Severe Storms

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0452 PM CDT Sun Mar 16 2025 Valid 181200Z - 241200Z An active fire weather pattern will continue across much of the central/southern Plains through the extended period with multiple days of Elevated to Critical fire weather expected. Extremely Critical fire weather conditions are likely on D3 - Tuesday across the southern Plains. Another day of Critical fire weather concerns is likely on D6 - Friday again across the Southern Plains. ...D3-Tuesday, Central High Plains, Southern Plains... Across the western Pacific, a trough will begin deepen D3 - Tuesday, with westerly flow aloft overspreading the southern Rockies. As this occurs, strong surface low development is expected by Tuesday afternoon. Models are starting to come into better agreement on the eastern placement of the dryline and resulting dry conditions, which has led to confidence in expanding the 70 percent probabilities eastward into central/eastern Oklahoma and Kansas as well as north-central Texas. Extremely Critical conditions will be possible across eastern New Mexico into the Texas Panhandle, possibly extending into western and central Oklahoma for a couple of hours Tuesday afternoon. Fuels in this region have undergone extreme fire weather conditions in the last few days and will be extremely susceptible to fire spread. Relative humidity reductions to 10-15 percent will be possible amid sustained winds 30+ mph. This will create a very dangerous conditions for fire spread on Tuesday afternoon. The dryline will mix eastward in the afternoon/evening on Tuesday, with relative humidity dropping rapidly amid very strong wind gusts along and ahead of the dryline/cold front along with a shift from southerly to southwest to westerly winds across portions of central Oklahoma and Kansas. This may lead to rapid changes in conditions and fire behavior near any ongoing fires. ...D4-D6 Wednesday/Friday, Southern Plains... Post frontal northwesterly flow will bring potential for Elevated fire concerns across portions of eastern New Mexico into the Texas Panhandle on D4 - Wednesday. Winds will shift to become southeasterly on Thursday, but conditions look to remain very dry and breezy, with slow moisture return late D5/Thursday into D6/Friday. A belt of strong west-southwesterly flow aloft will overspread southern Plains again on Friday with surface low development expected across Kansas/Oklahoma. On D6 - Friday 40 percent probabilities were upgraded to 70 percent across western Texas into the Texas and Oklahoma Panhandles to account for development of the next surface low across the central Plains. It is possible Elevated fire concerns continue D7 - Saturday and D8 - Sunday with strong post frontal northwesterly flow regime returning. ..Thornton.. 03/16/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 0235 CONCERNING TORNADO WATCH 54... FOR EASTERN PENNSYLVANIA...CENTRAL MARYLAND...AND NORTHERN VIRGINIA
Mesoscale Discussion 0235 NWS Storm Prediction Center Norman OK 0326 PM CDT Sun Mar 16 2025 Areas affected...eastern Pennsylvania...central Maryland...and northern Virginia Concerning...Tornado Watch 54... Valid 162026Z - 162200Z The severe weather threat for Tornado Watch 54 continues. SUMMARY...Sporadic damaging wind gusts are possible through the remainder of the afternoon. No watch is expected downstream of watch 54. DISCUSSION...Skies have cleared across northern Virginia into southern Pennsylvania over the past few hours which has allowed temperatures to increase into the 70s ahead of the line of storms. Despite the warming temperatures, instability has had little change as the warming has also started to mix out surface dewpoints with some sites across northern Virginia now falling into the mid 50s. MLCAPE around 250 J/kg should persist ahead of this line of storms for the next 1 to 2 hours which may allow for some sporadic damaging wind gusts from the more organized cells. In fact, a few weak supercell type structures have developed which will locally increase the damaging wind/brief tornado threat. Storm motions should keep these storms within watch 54 for the awhile longer. Therefore, by the time storms move east of the watch, stabilizing effects of early-evening transition should limit the surface-based instability. Therefore, no watch is anticipated downstream of watch 54 at this time. ..Bentley/Gleason.. 03/16/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...PHI...BGM...AKQ...CTP...LWX...RNK... LAT...LON 38267957 39177900 40497778 41277705 41567682 41577623 41247533 39927597 38567676 37657788 37607878 37717947 38267957 Read more

MD 0233 CONCERNING SEVERE THUNDERSTORM WATCH 55... FOR CENTRAL NEW YORK
Mesoscale Discussion 0233 NWS Storm Prediction Center Norman OK 0302 PM CDT Sun Mar 16 2025 Areas affected...central New York Concerning...Severe Thunderstorm Watch 55... Valid 162002Z - 162130Z The severe weather threat for Severe Thunderstorm Watch 55 continues. SUMMARY...The damaging wind gusts will persist for a few more hours across central New York before the threat wanes. DISCUSSION...A well-developed line of storms has produced numerous reports of damaging wind gusts and some measured severe wind gusts across western/central Pennsylvania and western New York. Some weak instability remains across central New York which may be sufficient to sustain these storms for a few more hours. Synoptic winds are gusting to 35-40 knots ahead of this line of storms and an 85 knot low-level jet is present on the BGM VWP around 2km. Therefore any surface based convection will likely have the potential for severe wind gusts this afternoon. Cloud cover is extensive ahead of this line of storms and the boundary layer will start to cool in the next 1 to 2 hours. Therefore, this line of storms is probably past its peak and should start to weaken in the next 1 to 2 hours. Severe thunderstorm watch 55 has been expanded ahead of these storms to cover this threat for that time period. While some local extensions of watch 55 may be necessary, no downstream watch is anticipated. ..Bentley/Gleason.. 03/16/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ALY...BGM...BUF...CTP... LAT...LON 42307415 41967504 41907614 41977696 42387734 42877744 43327738 43397701 43457658 43617642 43647609 43657527 43547461 42987427 42307415 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0301 PM CDT Sun Mar 16 2025 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF UPSTATE NEW YORK...THE MID-ATLANTIC...AND THE SOUTHEAST... ...SUMMARY... Damaging wind and a few tornadoes remain possible through the remainder of this afternoon and evening across parts of upstate New York, the Mid-Atlantic and the Southeast. ...20z Update... The main forecast changes for 20z have been to reduce probabilities behind the squall line ongoing over PA and western NY state, and expand slightly ahead of the more persistent bowing segments over northern NY. Lingering cloud cover and modest surface moisture greatly limit available buoyancy ahead of the line. With only a few hundred J/kg of MUCAPE, decreasing with eastward extent, a gradual loss in intensity is expected over the next several hours over northeastern PA and NY. Still, very strong gradient winds and flow aloft will support some potential for convective-enhanced damaging gusts through this evening. 300-400 m2/s2 of 0-3km SRH may also support the threat for a couple of brief QLCS tornadoes while the line maintains intensity. Probabilities have also be trimmed farther south over parts of the western Carolinas, GA and northern FL as the main convective band and cold front have shifted east. Some isolated thunderstorm redevelopment remains possible over parts of the Blue Ridge Mountains of western VA and into the central Carolinas where diurnal heating has steepened low-level lapse rates immediately ahead of the synoptic cold front. While confidence in severe potential is modest given meager buoyancy, the steep lapse rates could support damaging gusts or marginal hail, should more sustained convection redevelop as indicated by some CAMS. These storms may eventually shift eastward into the mid Atlantic late this afternoon and into the early evening, where low-level synoptic flow remains fairly strong. Will maintain the Slight Risk for damaging gusts and isolated tornado potential over parts of the Mid Atlantic into tonight. ..Lyons.. 03/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sun Mar 16 2025/ ...Ohio Valley into the Mid-Atlantic... A highly amplified upper trough over the MS Valley this morning will advance eastward over much of the eastern CONUS today. An embedded 100+ kt southwesterly mid-level jet and associated large-scale ascent will overspread the upper OH Valley and western Mid-Atlantic regions through this evening. The primary surface low over eastern Lower MI will develop northeastward into Ontario and Quebec through the day, while an attendant cold front sweeps eastward across the OH Valley/Mid-Atlantic through the period. Recent visible satellite imagery shows some clearing ahead of the synoptic cold front in eastern OH and western PA. Although low-level moisture will be somewhat limited, with surface dewpoints generally in the mid to upper 50s, cool mid-level temperatures will overspread the narrow warm sector this afternoon. This, combined with daytime heating, will support a narrow zone of up to 250-500 J/kg of MLCAPE just ahead of the cold front and/or pre-frontal trough, which should be sufficient for surface-based convection. Bands of low-topped thunderstorms have developed both along and just ahead of the cold front. This activity will move quickly east-northeastward across WV, western/central PA, and parts of NY through the day. With strong low/mid-level flow already in place per area VWPs, this line should pose a threat for mainly scattered damaging winds, with peak gusts perhaps reaching up to 60-70 mph. There will also be rather strong low-level shear in place, which may support some threat for a few tornadoes embedded within the line, especially if low-level flow can remain backed more to a southeasterly component. The northeastward extent of this severe wind and tornado risk into the Mid-Atlantic and NY remains unclear, as persistent cloud cover will inhibit daytime heating to some extent. Still, most guidance shows one or more lines persisting through the afternoon and evening while posing some wind threat. Severe probabilities have been adjusted northeastward across parts of the Mid-Atlantic to account for latest observational and guidance trends. ...Southeast/Carolinas... The southern portion of the highly amplified upper trough will continue eastward across the lower MS Valley and Southeast today, as an intense southerly low-level jet shifts east across north FL and the Carolinas through this evening. Ongoing pre-frontal convection has mostly weakened late this morning/early afternoon, with a couple of stronger cells persisting over southeast GA and north FL where greater low-level moisture and instability is present. Adequately enlarged low-level hodographs within a gradually destabilizing airmass (1000-1500 J/kg MLCAPE across north-central FL, with weaker instability over the coastal Carolinas) should continue to support organized convection through the afternoon and evening, before activity eventually moves offshore. Broken line segments (mainly Carolinas) and some supercells (mainly southeast GA and north FL) will pose a threat for scattered damaging winds (peak gusts up to 55-70 mph) and a few tornadoes. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0301 PM CDT Sun Mar 16 2025 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF UPSTATE NEW YORK...THE MID-ATLANTIC...AND THE SOUTHEAST... ...SUMMARY... Damaging wind and a few tornadoes remain possible through the remainder of this afternoon and evening across parts of upstate New York, the Mid-Atlantic and the Southeast. ...20z Update... The main forecast changes for 20z have been to reduce probabilities behind the squall line ongoing over PA and western NY state, and expand slightly ahead of the more persistent bowing segments over northern NY. Lingering cloud cover and modest surface moisture greatly limit available buoyancy ahead of the line. With only a few hundred J/kg of MUCAPE, decreasing with eastward extent, a gradual loss in intensity is expected over the next several hours over northeastern PA and NY. Still, very strong gradient winds and flow aloft will support some potential for convective-enhanced damaging gusts through this evening. 300-400 m2/s2 of 0-3km SRH may also support the threat for a couple of brief QLCS tornadoes while the line maintains intensity. Probabilities have also be trimmed farther south over parts of the western Carolinas, GA and northern FL as the main convective band and cold front have shifted east. Some isolated thunderstorm redevelopment remains possible over parts of the Blue Ridge Mountains of western VA and into the central Carolinas where diurnal heating has steepened low-level lapse rates immediately ahead of the synoptic cold front. While confidence in severe potential is modest given meager buoyancy, the steep lapse rates could support damaging gusts or marginal hail, should more sustained convection redevelop as indicated by some CAMS. These storms may eventually shift eastward into the mid Atlantic late this afternoon and into the early evening, where low-level synoptic flow remains fairly strong. Will maintain the Slight Risk for damaging gusts and isolated tornado potential over parts of the Mid Atlantic into tonight. ..Lyons.. 03/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sun Mar 16 2025/ ...Ohio Valley into the Mid-Atlantic... A highly amplified upper trough over the MS Valley this morning will advance eastward over much of the eastern CONUS today. An embedded 100+ kt southwesterly mid-level jet and associated large-scale ascent will overspread the upper OH Valley and western Mid-Atlantic regions through this evening. The primary surface low over eastern Lower MI will develop northeastward into Ontario and Quebec through the day, while an attendant cold front sweeps eastward across the OH Valley/Mid-Atlantic through the period. Recent visible satellite imagery shows some clearing ahead of the synoptic cold front in eastern OH and western PA. Although low-level moisture will be somewhat limited, with surface dewpoints generally in the mid to upper 50s, cool mid-level temperatures will overspread the narrow warm sector this afternoon. This, combined with daytime heating, will support a narrow zone of up to 250-500 J/kg of MLCAPE just ahead of the cold front and/or pre-frontal trough, which should be sufficient for surface-based convection. Bands of low-topped thunderstorms have developed both along and just ahead of the cold front. This activity will move quickly east-northeastward across WV, western/central PA, and parts of NY through the day. With strong low/mid-level flow already in place per area VWPs, this line should pose a threat for mainly scattered damaging winds, with peak gusts perhaps reaching up to 60-70 mph. There will also be rather strong low-level shear in place, which may support some threat for a few tornadoes embedded within the line, especially if low-level flow can remain backed more to a southeasterly component. The northeastward extent of this severe wind and tornado risk into the Mid-Atlantic and NY remains unclear, as persistent cloud cover will inhibit daytime heating to some extent. Still, most guidance shows one or more lines persisting through the afternoon and evening while posing some wind threat. Severe probabilities have been adjusted northeastward across parts of the Mid-Atlantic to account for latest observational and guidance trends. ...Southeast/Carolinas... The southern portion of the highly amplified upper trough will continue eastward across the lower MS Valley and Southeast today, as an intense southerly low-level jet shifts east across north FL and the Carolinas through this evening. Ongoing pre-frontal convection has mostly weakened late this morning/early afternoon, with a couple of stronger cells persisting over southeast GA and north FL where greater low-level moisture and instability is present. Adequately enlarged low-level hodographs within a gradually destabilizing airmass (1000-1500 J/kg MLCAPE across north-central FL, with weaker instability over the coastal Carolinas) should continue to support organized convection through the afternoon and evening, before activity eventually moves offshore. Broken line segments (mainly Carolinas) and some supercells (mainly southeast GA and north FL) will pose a threat for scattered damaging winds (peak gusts up to 55-70 mph) and a few tornadoes. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0301 PM CDT Sun Mar 16 2025 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF UPSTATE NEW YORK...THE MID-ATLANTIC...AND THE SOUTHEAST... ...SUMMARY... Damaging wind and a few tornadoes remain possible through the remainder of this afternoon and evening across parts of upstate New York, the Mid-Atlantic and the Southeast. ...20z Update... The main forecast changes for 20z have been to reduce probabilities behind the squall line ongoing over PA and western NY state, and expand slightly ahead of the more persistent bowing segments over northern NY. Lingering cloud cover and modest surface moisture greatly limit available buoyancy ahead of the line. With only a few hundred J/kg of MUCAPE, decreasing with eastward extent, a gradual loss in intensity is expected over the next several hours over northeastern PA and NY. Still, very strong gradient winds and flow aloft will support some potential for convective-enhanced damaging gusts through this evening. 300-400 m2/s2 of 0-3km SRH may also support the threat for a couple of brief QLCS tornadoes while the line maintains intensity. Probabilities have also be trimmed farther south over parts of the western Carolinas, GA and northern FL as the main convective band and cold front have shifted east. Some isolated thunderstorm redevelopment remains possible over parts of the Blue Ridge Mountains of western VA and into the central Carolinas where diurnal heating has steepened low-level lapse rates immediately ahead of the synoptic cold front. While confidence in severe potential is modest given meager buoyancy, the steep lapse rates could support damaging gusts or marginal hail, should more sustained convection redevelop as indicated by some CAMS. These storms may eventually shift eastward into the mid Atlantic late this afternoon and into the early evening, where low-level synoptic flow remains fairly strong. Will maintain the Slight Risk for damaging gusts and isolated tornado potential over parts of the Mid Atlantic into tonight. ..Lyons.. 03/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sun Mar 16 2025/ ...Ohio Valley into the Mid-Atlantic... A highly amplified upper trough over the MS Valley this morning will advance eastward over much of the eastern CONUS today. An embedded 100+ kt southwesterly mid-level jet and associated large-scale ascent will overspread the upper OH Valley and western Mid-Atlantic regions through this evening. The primary surface low over eastern Lower MI will develop northeastward into Ontario and Quebec through the day, while an attendant cold front sweeps eastward across the OH Valley/Mid-Atlantic through the period. Recent visible satellite imagery shows some clearing ahead of the synoptic cold front in eastern OH and western PA. Although low-level moisture will be somewhat limited, with surface dewpoints generally in the mid to upper 50s, cool mid-level temperatures will overspread the narrow warm sector this afternoon. This, combined with daytime heating, will support a narrow zone of up to 250-500 J/kg of MLCAPE just ahead of the cold front and/or pre-frontal trough, which should be sufficient for surface-based convection. Bands of low-topped thunderstorms have developed both along and just ahead of the cold front. This activity will move quickly east-northeastward across WV, western/central PA, and parts of NY through the day. With strong low/mid-level flow already in place per area VWPs, this line should pose a threat for mainly scattered damaging winds, with peak gusts perhaps reaching up to 60-70 mph. There will also be rather strong low-level shear in place, which may support some threat for a few tornadoes embedded within the line, especially if low-level flow can remain backed more to a southeasterly component. The northeastward extent of this severe wind and tornado risk into the Mid-Atlantic and NY remains unclear, as persistent cloud cover will inhibit daytime heating to some extent. Still, most guidance shows one or more lines persisting through the afternoon and evening while posing some wind threat. Severe probabilities have been adjusted northeastward across parts of the Mid-Atlantic to account for latest observational and guidance trends. ...Southeast/Carolinas... The southern portion of the highly amplified upper trough will continue eastward across the lower MS Valley and Southeast today, as an intense southerly low-level jet shifts east across north FL and the Carolinas through this evening. Ongoing pre-frontal convection has mostly weakened late this morning/early afternoon, with a couple of stronger cells persisting over southeast GA and north FL where greater low-level moisture and instability is present. Adequately enlarged low-level hodographs within a gradually destabilizing airmass (1000-1500 J/kg MLCAPE across north-central FL, with weaker instability over the coastal Carolinas) should continue to support organized convection through the afternoon and evening, before activity eventually moves offshore. Broken line segments (mainly Carolinas) and some supercells (mainly southeast GA and north FL) will pose a threat for scattered damaging winds (peak gusts up to 55-70 mph) and a few tornadoes. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0301 PM CDT Sun Mar 16 2025 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF UPSTATE NEW YORK...THE MID-ATLANTIC...AND THE SOUTHEAST... ...SUMMARY... Damaging wind and a few tornadoes remain possible through the remainder of this afternoon and evening across parts of upstate New York, the Mid-Atlantic and the Southeast. ...20z Update... The main forecast changes for 20z have been to reduce probabilities behind the squall line ongoing over PA and western NY state, and expand slightly ahead of the more persistent bowing segments over northern NY. Lingering cloud cover and modest surface moisture greatly limit available buoyancy ahead of the line. With only a few hundred J/kg of MUCAPE, decreasing with eastward extent, a gradual loss in intensity is expected over the next several hours over northeastern PA and NY. Still, very strong gradient winds and flow aloft will support some potential for convective-enhanced damaging gusts through this evening. 300-400 m2/s2 of 0-3km SRH may also support the threat for a couple of brief QLCS tornadoes while the line maintains intensity. Probabilities have also be trimmed farther south over parts of the western Carolinas, GA and northern FL as the main convective band and cold front have shifted east. Some isolated thunderstorm redevelopment remains possible over parts of the Blue Ridge Mountains of western VA and into the central Carolinas where diurnal heating has steepened low-level lapse rates immediately ahead of the synoptic cold front. While confidence in severe potential is modest given meager buoyancy, the steep lapse rates could support damaging gusts or marginal hail, should more sustained convection redevelop as indicated by some CAMS. These storms may eventually shift eastward into the mid Atlantic late this afternoon and into the early evening, where low-level synoptic flow remains fairly strong. Will maintain the Slight Risk for damaging gusts and isolated tornado potential over parts of the Mid Atlantic into tonight. ..Lyons.. 03/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sun Mar 16 2025/ ...Ohio Valley into the Mid-Atlantic... A highly amplified upper trough over the MS Valley this morning will advance eastward over much of the eastern CONUS today. An embedded 100+ kt southwesterly mid-level jet and associated large-scale ascent will overspread the upper OH Valley and western Mid-Atlantic regions through this evening. The primary surface low over eastern Lower MI will develop northeastward into Ontario and Quebec through the day, while an attendant cold front sweeps eastward across the OH Valley/Mid-Atlantic through the period. Recent visible satellite imagery shows some clearing ahead of the synoptic cold front in eastern OH and western PA. Although low-level moisture will be somewhat limited, with surface dewpoints generally in the mid to upper 50s, cool mid-level temperatures will overspread the narrow warm sector this afternoon. This, combined with daytime heating, will support a narrow zone of up to 250-500 J/kg of MLCAPE just ahead of the cold front and/or pre-frontal trough, which should be sufficient for surface-based convection. Bands of low-topped thunderstorms have developed both along and just ahead of the cold front. This activity will move quickly east-northeastward across WV, western/central PA, and parts of NY through the day. With strong low/mid-level flow already in place per area VWPs, this line should pose a threat for mainly scattered damaging winds, with peak gusts perhaps reaching up to 60-70 mph. There will also be rather strong low-level shear in place, which may support some threat for a few tornadoes embedded within the line, especially if low-level flow can remain backed more to a southeasterly component. The northeastward extent of this severe wind and tornado risk into the Mid-Atlantic and NY remains unclear, as persistent cloud cover will inhibit daytime heating to some extent. Still, most guidance shows one or more lines persisting through the afternoon and evening while posing some wind threat. Severe probabilities have been adjusted northeastward across parts of the Mid-Atlantic to account for latest observational and guidance trends. ...Southeast/Carolinas... The southern portion of the highly amplified upper trough will continue eastward across the lower MS Valley and Southeast today, as an intense southerly low-level jet shifts east across north FL and the Carolinas through this evening. Ongoing pre-frontal convection has mostly weakened late this morning/early afternoon, with a couple of stronger cells persisting over southeast GA and north FL where greater low-level moisture and instability is present. Adequately enlarged low-level hodographs within a gradually destabilizing airmass (1000-1500 J/kg MLCAPE across north-central FL, with weaker instability over the coastal Carolinas) should continue to support organized convection through the afternoon and evening, before activity eventually moves offshore. Broken line segments (mainly Carolinas) and some supercells (mainly southeast GA and north FL) will pose a threat for scattered damaging winds (peak gusts up to 55-70 mph) and a few tornadoes. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0301 PM CDT Sun Mar 16 2025 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF UPSTATE NEW YORK...THE MID-ATLANTIC...AND THE SOUTHEAST... ...SUMMARY... Damaging wind and a few tornadoes remain possible through the remainder of this afternoon and evening across parts of upstate New York, the Mid-Atlantic and the Southeast. ...20z Update... The main forecast changes for 20z have been to reduce probabilities behind the squall line ongoing over PA and western NY state, and expand slightly ahead of the more persistent bowing segments over northern NY. Lingering cloud cover and modest surface moisture greatly limit available buoyancy ahead of the line. With only a few hundred J/kg of MUCAPE, decreasing with eastward extent, a gradual loss in intensity is expected over the next several hours over northeastern PA and NY. Still, very strong gradient winds and flow aloft will support some potential for convective-enhanced damaging gusts through this evening. 300-400 m2/s2 of 0-3km SRH may also support the threat for a couple of brief QLCS tornadoes while the line maintains intensity. Probabilities have also be trimmed farther south over parts of the western Carolinas, GA and northern FL as the main convective band and cold front have shifted east. Some isolated thunderstorm redevelopment remains possible over parts of the Blue Ridge Mountains of western VA and into the central Carolinas where diurnal heating has steepened low-level lapse rates immediately ahead of the synoptic cold front. While confidence in severe potential is modest given meager buoyancy, the steep lapse rates could support damaging gusts or marginal hail, should more sustained convection redevelop as indicated by some CAMS. These storms may eventually shift eastward into the mid Atlantic late this afternoon and into the early evening, where low-level synoptic flow remains fairly strong. Will maintain the Slight Risk for damaging gusts and isolated tornado potential over parts of the Mid Atlantic into tonight. ..Lyons.. 03/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sun Mar 16 2025/ ...Ohio Valley into the Mid-Atlantic... A highly amplified upper trough over the MS Valley this morning will advance eastward over much of the eastern CONUS today. An embedded 100+ kt southwesterly mid-level jet and associated large-scale ascent will overspread the upper OH Valley and western Mid-Atlantic regions through this evening. The primary surface low over eastern Lower MI will develop northeastward into Ontario and Quebec through the day, while an attendant cold front sweeps eastward across the OH Valley/Mid-Atlantic through the period. Recent visible satellite imagery shows some clearing ahead of the synoptic cold front in eastern OH and western PA. Although low-level moisture will be somewhat limited, with surface dewpoints generally in the mid to upper 50s, cool mid-level temperatures will overspread the narrow warm sector this afternoon. This, combined with daytime heating, will support a narrow zone of up to 250-500 J/kg of MLCAPE just ahead of the cold front and/or pre-frontal trough, which should be sufficient for surface-based convection. Bands of low-topped thunderstorms have developed both along and just ahead of the cold front. This activity will move quickly east-northeastward across WV, western/central PA, and parts of NY through the day. With strong low/mid-level flow already in place per area VWPs, this line should pose a threat for mainly scattered damaging winds, with peak gusts perhaps reaching up to 60-70 mph. There will also be rather strong low-level shear in place, which may support some threat for a few tornadoes embedded within the line, especially if low-level flow can remain backed more to a southeasterly component. The northeastward extent of this severe wind and tornado risk into the Mid-Atlantic and NY remains unclear, as persistent cloud cover will inhibit daytime heating to some extent. Still, most guidance shows one or more lines persisting through the afternoon and evening while posing some wind threat. Severe probabilities have been adjusted northeastward across parts of the Mid-Atlantic to account for latest observational and guidance trends. ...Southeast/Carolinas... The southern portion of the highly amplified upper trough will continue eastward across the lower MS Valley and Southeast today, as an intense southerly low-level jet shifts east across north FL and the Carolinas through this evening. Ongoing pre-frontal convection has mostly weakened late this morning/early afternoon, with a couple of stronger cells persisting over southeast GA and north FL where greater low-level moisture and instability is present. Adequately enlarged low-level hodographs within a gradually destabilizing airmass (1000-1500 J/kg MLCAPE across north-central FL, with weaker instability over the coastal Carolinas) should continue to support organized convection through the afternoon and evening, before activity eventually moves offshore. Broken line segments (mainly Carolinas) and some supercells (mainly southeast GA and north FL) will pose a threat for scattered damaging winds (peak gusts up to 55-70 mph) and a few tornadoes. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0301 PM CDT Sun Mar 16 2025 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF UPSTATE NEW YORK...THE MID-ATLANTIC...AND THE SOUTHEAST... ...SUMMARY... Damaging wind and a few tornadoes remain possible through the remainder of this afternoon and evening across parts of upstate New York, the Mid-Atlantic and the Southeast. ...20z Update... The main forecast changes for 20z have been to reduce probabilities behind the squall line ongoing over PA and western NY state, and expand slightly ahead of the more persistent bowing segments over northern NY. Lingering cloud cover and modest surface moisture greatly limit available buoyancy ahead of the line. With only a few hundred J/kg of MUCAPE, decreasing with eastward extent, a gradual loss in intensity is expected over the next several hours over northeastern PA and NY. Still, very strong gradient winds and flow aloft will support some potential for convective-enhanced damaging gusts through this evening. 300-400 m2/s2 of 0-3km SRH may also support the threat for a couple of brief QLCS tornadoes while the line maintains intensity. Probabilities have also be trimmed farther south over parts of the western Carolinas, GA and northern FL as the main convective band and cold front have shifted east. Some isolated thunderstorm redevelopment remains possible over parts of the Blue Ridge Mountains of western VA and into the central Carolinas where diurnal heating has steepened low-level lapse rates immediately ahead of the synoptic cold front. While confidence in severe potential is modest given meager buoyancy, the steep lapse rates could support damaging gusts or marginal hail, should more sustained convection redevelop as indicated by some CAMS. These storms may eventually shift eastward into the mid Atlantic late this afternoon and into the early evening, where low-level synoptic flow remains fairly strong. Will maintain the Slight Risk for damaging gusts and isolated tornado potential over parts of the Mid Atlantic into tonight. ..Lyons.. 03/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sun Mar 16 2025/ ...Ohio Valley into the Mid-Atlantic... A highly amplified upper trough over the MS Valley this morning will advance eastward over much of the eastern CONUS today. An embedded 100+ kt southwesterly mid-level jet and associated large-scale ascent will overspread the upper OH Valley and western Mid-Atlantic regions through this evening. The primary surface low over eastern Lower MI will develop northeastward into Ontario and Quebec through the day, while an attendant cold front sweeps eastward across the OH Valley/Mid-Atlantic through the period. Recent visible satellite imagery shows some clearing ahead of the synoptic cold front in eastern OH and western PA. Although low-level moisture will be somewhat limited, with surface dewpoints generally in the mid to upper 50s, cool mid-level temperatures will overspread the narrow warm sector this afternoon. This, combined with daytime heating, will support a narrow zone of up to 250-500 J/kg of MLCAPE just ahead of the cold front and/or pre-frontal trough, which should be sufficient for surface-based convection. Bands of low-topped thunderstorms have developed both along and just ahead of the cold front. This activity will move quickly east-northeastward across WV, western/central PA, and parts of NY through the day. With strong low/mid-level flow already in place per area VWPs, this line should pose a threat for mainly scattered damaging winds, with peak gusts perhaps reaching up to 60-70 mph. There will also be rather strong low-level shear in place, which may support some threat for a few tornadoes embedded within the line, especially if low-level flow can remain backed more to a southeasterly component. The northeastward extent of this severe wind and tornado risk into the Mid-Atlantic and NY remains unclear, as persistent cloud cover will inhibit daytime heating to some extent. Still, most guidance shows one or more lines persisting through the afternoon and evening while posing some wind threat. Severe probabilities have been adjusted northeastward across parts of the Mid-Atlantic to account for latest observational and guidance trends. ...Southeast/Carolinas... The southern portion of the highly amplified upper trough will continue eastward across the lower MS Valley and Southeast today, as an intense southerly low-level jet shifts east across north FL and the Carolinas through this evening. Ongoing pre-frontal convection has mostly weakened late this morning/early afternoon, with a couple of stronger cells persisting over southeast GA and north FL where greater low-level moisture and instability is present. Adequately enlarged low-level hodographs within a gradually destabilizing airmass (1000-1500 J/kg MLCAPE across north-central FL, with weaker instability over the coastal Carolinas) should continue to support organized convection through the afternoon and evening, before activity eventually moves offshore. Broken line segments (mainly Carolinas) and some supercells (mainly southeast GA and north FL) will pose a threat for scattered damaging winds (peak gusts up to 55-70 mph) and a few tornadoes. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0301 PM CDT Sun Mar 16 2025 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF UPSTATE NEW YORK...THE MID-ATLANTIC...AND THE SOUTHEAST... ...SUMMARY... Damaging wind and a few tornadoes remain possible through the remainder of this afternoon and evening across parts of upstate New York, the Mid-Atlantic and the Southeast. ...20z Update... The main forecast changes for 20z have been to reduce probabilities behind the squall line ongoing over PA and western NY state, and expand slightly ahead of the more persistent bowing segments over northern NY. Lingering cloud cover and modest surface moisture greatly limit available buoyancy ahead of the line. With only a few hundred J/kg of MUCAPE, decreasing with eastward extent, a gradual loss in intensity is expected over the next several hours over northeastern PA and NY. Still, very strong gradient winds and flow aloft will support some potential for convective-enhanced damaging gusts through this evening. 300-400 m2/s2 of 0-3km SRH may also support the threat for a couple of brief QLCS tornadoes while the line maintains intensity. Probabilities have also be trimmed farther south over parts of the western Carolinas, GA and northern FL as the main convective band and cold front have shifted east. Some isolated thunderstorm redevelopment remains possible over parts of the Blue Ridge Mountains of western VA and into the central Carolinas where diurnal heating has steepened low-level lapse rates immediately ahead of the synoptic cold front. While confidence in severe potential is modest given meager buoyancy, the steep lapse rates could support damaging gusts or marginal hail, should more sustained convection redevelop as indicated by some CAMS. These storms may eventually shift eastward into the mid Atlantic late this afternoon and into the early evening, where low-level synoptic flow remains fairly strong. Will maintain the Slight Risk for damaging gusts and isolated tornado potential over parts of the Mid Atlantic into tonight. ..Lyons.. 03/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sun Mar 16 2025/ ...Ohio Valley into the Mid-Atlantic... A highly amplified upper trough over the MS Valley this morning will advance eastward over much of the eastern CONUS today. An embedded 100+ kt southwesterly mid-level jet and associated large-scale ascent will overspread the upper OH Valley and western Mid-Atlantic regions through this evening. The primary surface low over eastern Lower MI will develop northeastward into Ontario and Quebec through the day, while an attendant cold front sweeps eastward across the OH Valley/Mid-Atlantic through the period. Recent visible satellite imagery shows some clearing ahead of the synoptic cold front in eastern OH and western PA. Although low-level moisture will be somewhat limited, with surface dewpoints generally in the mid to upper 50s, cool mid-level temperatures will overspread the narrow warm sector this afternoon. This, combined with daytime heating, will support a narrow zone of up to 250-500 J/kg of MLCAPE just ahead of the cold front and/or pre-frontal trough, which should be sufficient for surface-based convection. Bands of low-topped thunderstorms have developed both along and just ahead of the cold front. This activity will move quickly east-northeastward across WV, western/central PA, and parts of NY through the day. With strong low/mid-level flow already in place per area VWPs, this line should pose a threat for mainly scattered damaging winds, with peak gusts perhaps reaching up to 60-70 mph. There will also be rather strong low-level shear in place, which may support some threat for a few tornadoes embedded within the line, especially if low-level flow can remain backed more to a southeasterly component. The northeastward extent of this severe wind and tornado risk into the Mid-Atlantic and NY remains unclear, as persistent cloud cover will inhibit daytime heating to some extent. Still, most guidance shows one or more lines persisting through the afternoon and evening while posing some wind threat. Severe probabilities have been adjusted northeastward across parts of the Mid-Atlantic to account for latest observational and guidance trends. ...Southeast/Carolinas... The southern portion of the highly amplified upper trough will continue eastward across the lower MS Valley and Southeast today, as an intense southerly low-level jet shifts east across north FL and the Carolinas through this evening. Ongoing pre-frontal convection has mostly weakened late this morning/early afternoon, with a couple of stronger cells persisting over southeast GA and north FL where greater low-level moisture and instability is present. Adequately enlarged low-level hodographs within a gradually destabilizing airmass (1000-1500 J/kg MLCAPE across north-central FL, with weaker instability over the coastal Carolinas) should continue to support organized convection through the afternoon and evening, before activity eventually moves offshore. Broken line segments (mainly Carolinas) and some supercells (mainly southeast GA and north FL) will pose a threat for scattered damaging winds (peak gusts up to 55-70 mph) and a few tornadoes. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0301 PM CDT Sun Mar 16 2025 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF UPSTATE NEW YORK...THE MID-ATLANTIC...AND THE SOUTHEAST... ...SUMMARY... Damaging wind and a few tornadoes remain possible through the remainder of this afternoon and evening across parts of upstate New York, the Mid-Atlantic and the Southeast. ...20z Update... The main forecast changes for 20z have been to reduce probabilities behind the squall line ongoing over PA and western NY state, and expand slightly ahead of the more persistent bowing segments over northern NY. Lingering cloud cover and modest surface moisture greatly limit available buoyancy ahead of the line. With only a few hundred J/kg of MUCAPE, decreasing with eastward extent, a gradual loss in intensity is expected over the next several hours over northeastern PA and NY. Still, very strong gradient winds and flow aloft will support some potential for convective-enhanced damaging gusts through this evening. 300-400 m2/s2 of 0-3km SRH may also support the threat for a couple of brief QLCS tornadoes while the line maintains intensity. Probabilities have also be trimmed farther south over parts of the western Carolinas, GA and northern FL as the main convective band and cold front have shifted east. Some isolated thunderstorm redevelopment remains possible over parts of the Blue Ridge Mountains of western VA and into the central Carolinas where diurnal heating has steepened low-level lapse rates immediately ahead of the synoptic cold front. While confidence in severe potential is modest given meager buoyancy, the steep lapse rates could support damaging gusts or marginal hail, should more sustained convection redevelop as indicated by some CAMS. These storms may eventually shift eastward into the mid Atlantic late this afternoon and into the early evening, where low-level synoptic flow remains fairly strong. Will maintain the Slight Risk for damaging gusts and isolated tornado potential over parts of the Mid Atlantic into tonight. ..Lyons.. 03/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sun Mar 16 2025/ ...Ohio Valley into the Mid-Atlantic... A highly amplified upper trough over the MS Valley this morning will advance eastward over much of the eastern CONUS today. An embedded 100+ kt southwesterly mid-level jet and associated large-scale ascent will overspread the upper OH Valley and western Mid-Atlantic regions through this evening. The primary surface low over eastern Lower MI will develop northeastward into Ontario and Quebec through the day, while an attendant cold front sweeps eastward across the OH Valley/Mid-Atlantic through the period. Recent visible satellite imagery shows some clearing ahead of the synoptic cold front in eastern OH and western PA. Although low-level moisture will be somewhat limited, with surface dewpoints generally in the mid to upper 50s, cool mid-level temperatures will overspread the narrow warm sector this afternoon. This, combined with daytime heating, will support a narrow zone of up to 250-500 J/kg of MLCAPE just ahead of the cold front and/or pre-frontal trough, which should be sufficient for surface-based convection. Bands of low-topped thunderstorms have developed both along and just ahead of the cold front. This activity will move quickly east-northeastward across WV, western/central PA, and parts of NY through the day. With strong low/mid-level flow already in place per area VWPs, this line should pose a threat for mainly scattered damaging winds, with peak gusts perhaps reaching up to 60-70 mph. There will also be rather strong low-level shear in place, which may support some threat for a few tornadoes embedded within the line, especially if low-level flow can remain backed more to a southeasterly component. The northeastward extent of this severe wind and tornado risk into the Mid-Atlantic and NY remains unclear, as persistent cloud cover will inhibit daytime heating to some extent. Still, most guidance shows one or more lines persisting through the afternoon and evening while posing some wind threat. Severe probabilities have been adjusted northeastward across parts of the Mid-Atlantic to account for latest observational and guidance trends. ...Southeast/Carolinas... The southern portion of the highly amplified upper trough will continue eastward across the lower MS Valley and Southeast today, as an intense southerly low-level jet shifts east across north FL and the Carolinas through this evening. Ongoing pre-frontal convection has mostly weakened late this morning/early afternoon, with a couple of stronger cells persisting over southeast GA and north FL where greater low-level moisture and instability is present. Adequately enlarged low-level hodographs within a gradually destabilizing airmass (1000-1500 J/kg MLCAPE across north-central FL, with weaker instability over the coastal Carolinas) should continue to support organized convection through the afternoon and evening, before activity eventually moves offshore. Broken line segments (mainly Carolinas) and some supercells (mainly southeast GA and north FL) will pose a threat for scattered damaging winds (peak gusts up to 55-70 mph) and a few tornadoes. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0301 PM CDT Sun Mar 16 2025 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF UPSTATE NEW YORK...THE MID-ATLANTIC...AND THE SOUTHEAST... ...SUMMARY... Damaging wind and a few tornadoes remain possible through the remainder of this afternoon and evening across parts of upstate New York, the Mid-Atlantic and the Southeast. ...20z Update... The main forecast changes for 20z have been to reduce probabilities behind the squall line ongoing over PA and western NY state, and expand slightly ahead of the more persistent bowing segments over northern NY. Lingering cloud cover and modest surface moisture greatly limit available buoyancy ahead of the line. With only a few hundred J/kg of MUCAPE, decreasing with eastward extent, a gradual loss in intensity is expected over the next several hours over northeastern PA and NY. Still, very strong gradient winds and flow aloft will support some potential for convective-enhanced damaging gusts through this evening. 300-400 m2/s2 of 0-3km SRH may also support the threat for a couple of brief QLCS tornadoes while the line maintains intensity. Probabilities have also be trimmed farther south over parts of the western Carolinas, GA and northern FL as the main convective band and cold front have shifted east. Some isolated thunderstorm redevelopment remains possible over parts of the Blue Ridge Mountains of western VA and into the central Carolinas where diurnal heating has steepened low-level lapse rates immediately ahead of the synoptic cold front. While confidence in severe potential is modest given meager buoyancy, the steep lapse rates could support damaging gusts or marginal hail, should more sustained convection redevelop as indicated by some CAMS. These storms may eventually shift eastward into the mid Atlantic late this afternoon and into the early evening, where low-level synoptic flow remains fairly strong. Will maintain the Slight Risk for damaging gusts and isolated tornado potential over parts of the Mid Atlantic into tonight. ..Lyons.. 03/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sun Mar 16 2025/ ...Ohio Valley into the Mid-Atlantic... A highly amplified upper trough over the MS Valley this morning will advance eastward over much of the eastern CONUS today. An embedded 100+ kt southwesterly mid-level jet and associated large-scale ascent will overspread the upper OH Valley and western Mid-Atlantic regions through this evening. The primary surface low over eastern Lower MI will develop northeastward into Ontario and Quebec through the day, while an attendant cold front sweeps eastward across the OH Valley/Mid-Atlantic through the period. Recent visible satellite imagery shows some clearing ahead of the synoptic cold front in eastern OH and western PA. Although low-level moisture will be somewhat limited, with surface dewpoints generally in the mid to upper 50s, cool mid-level temperatures will overspread the narrow warm sector this afternoon. This, combined with daytime heating, will support a narrow zone of up to 250-500 J/kg of MLCAPE just ahead of the cold front and/or pre-frontal trough, which should be sufficient for surface-based convection. Bands of low-topped thunderstorms have developed both along and just ahead of the cold front. This activity will move quickly east-northeastward across WV, western/central PA, and parts of NY through the day. With strong low/mid-level flow already in place per area VWPs, this line should pose a threat for mainly scattered damaging winds, with peak gusts perhaps reaching up to 60-70 mph. There will also be rather strong low-level shear in place, which may support some threat for a few tornadoes embedded within the line, especially if low-level flow can remain backed more to a southeasterly component. The northeastward extent of this severe wind and tornado risk into the Mid-Atlantic and NY remains unclear, as persistent cloud cover will inhibit daytime heating to some extent. Still, most guidance shows one or more lines persisting through the afternoon and evening while posing some wind threat. Severe probabilities have been adjusted northeastward across parts of the Mid-Atlantic to account for latest observational and guidance trends. ...Southeast/Carolinas... The southern portion of the highly amplified upper trough will continue eastward across the lower MS Valley and Southeast today, as an intense southerly low-level jet shifts east across north FL and the Carolinas through this evening. Ongoing pre-frontal convection has mostly weakened late this morning/early afternoon, with a couple of stronger cells persisting over southeast GA and north FL where greater low-level moisture and instability is present. Adequately enlarged low-level hodographs within a gradually destabilizing airmass (1000-1500 J/kg MLCAPE across north-central FL, with weaker instability over the coastal Carolinas) should continue to support organized convection through the afternoon and evening, before activity eventually moves offshore. Broken line segments (mainly Carolinas) and some supercells (mainly southeast GA and north FL) will pose a threat for scattered damaging winds (peak gusts up to 55-70 mph) and a few tornadoes. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0301 PM CDT Sun Mar 16 2025 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF UPSTATE NEW YORK...THE MID-ATLANTIC...AND THE SOUTHEAST... ...SUMMARY... Damaging wind and a few tornadoes remain possible through the remainder of this afternoon and evening across parts of upstate New York, the Mid-Atlantic and the Southeast. ...20z Update... The main forecast changes for 20z have been to reduce probabilities behind the squall line ongoing over PA and western NY state, and expand slightly ahead of the more persistent bowing segments over northern NY. Lingering cloud cover and modest surface moisture greatly limit available buoyancy ahead of the line. With only a few hundred J/kg of MUCAPE, decreasing with eastward extent, a gradual loss in intensity is expected over the next several hours over northeastern PA and NY. Still, very strong gradient winds and flow aloft will support some potential for convective-enhanced damaging gusts through this evening. 300-400 m2/s2 of 0-3km SRH may also support the threat for a couple of brief QLCS tornadoes while the line maintains intensity. Probabilities have also be trimmed farther south over parts of the western Carolinas, GA and northern FL as the main convective band and cold front have shifted east. Some isolated thunderstorm redevelopment remains possible over parts of the Blue Ridge Mountains of western VA and into the central Carolinas where diurnal heating has steepened low-level lapse rates immediately ahead of the synoptic cold front. While confidence in severe potential is modest given meager buoyancy, the steep lapse rates could support damaging gusts or marginal hail, should more sustained convection redevelop as indicated by some CAMS. These storms may eventually shift eastward into the mid Atlantic late this afternoon and into the early evening, where low-level synoptic flow remains fairly strong. Will maintain the Slight Risk for damaging gusts and isolated tornado potential over parts of the Mid Atlantic into tonight. ..Lyons.. 03/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sun Mar 16 2025/ ...Ohio Valley into the Mid-Atlantic... A highly amplified upper trough over the MS Valley this morning will advance eastward over much of the eastern CONUS today. An embedded 100+ kt southwesterly mid-level jet and associated large-scale ascent will overspread the upper OH Valley and western Mid-Atlantic regions through this evening. The primary surface low over eastern Lower MI will develop northeastward into Ontario and Quebec through the day, while an attendant cold front sweeps eastward across the OH Valley/Mid-Atlantic through the period. Recent visible satellite imagery shows some clearing ahead of the synoptic cold front in eastern OH and western PA. Although low-level moisture will be somewhat limited, with surface dewpoints generally in the mid to upper 50s, cool mid-level temperatures will overspread the narrow warm sector this afternoon. This, combined with daytime heating, will support a narrow zone of up to 250-500 J/kg of MLCAPE just ahead of the cold front and/or pre-frontal trough, which should be sufficient for surface-based convection. Bands of low-topped thunderstorms have developed both along and just ahead of the cold front. This activity will move quickly east-northeastward across WV, western/central PA, and parts of NY through the day. With strong low/mid-level flow already in place per area VWPs, this line should pose a threat for mainly scattered damaging winds, with peak gusts perhaps reaching up to 60-70 mph. There will also be rather strong low-level shear in place, which may support some threat for a few tornadoes embedded within the line, especially if low-level flow can remain backed more to a southeasterly component. The northeastward extent of this severe wind and tornado risk into the Mid-Atlantic and NY remains unclear, as persistent cloud cover will inhibit daytime heating to some extent. Still, most guidance shows one or more lines persisting through the afternoon and evening while posing some wind threat. Severe probabilities have been adjusted northeastward across parts of the Mid-Atlantic to account for latest observational and guidance trends. ...Southeast/Carolinas... The southern portion of the highly amplified upper trough will continue eastward across the lower MS Valley and Southeast today, as an intense southerly low-level jet shifts east across north FL and the Carolinas through this evening. Ongoing pre-frontal convection has mostly weakened late this morning/early afternoon, with a couple of stronger cells persisting over southeast GA and north FL where greater low-level moisture and instability is present. Adequately enlarged low-level hodographs within a gradually destabilizing airmass (1000-1500 J/kg MLCAPE across north-central FL, with weaker instability over the coastal Carolinas) should continue to support organized convection through the afternoon and evening, before activity eventually moves offshore. Broken line segments (mainly Carolinas) and some supercells (mainly southeast GA and north FL) will pose a threat for scattered damaging winds (peak gusts up to 55-70 mph) and a few tornadoes. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0301 PM CDT Sun Mar 16 2025 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF UPSTATE NEW YORK...THE MID-ATLANTIC...AND THE SOUTHEAST... ...SUMMARY... Damaging wind and a few tornadoes remain possible through the remainder of this afternoon and evening across parts of upstate New York, the Mid-Atlantic and the Southeast. ...20z Update... The main forecast changes for 20z have been to reduce probabilities behind the squall line ongoing over PA and western NY state, and expand slightly ahead of the more persistent bowing segments over northern NY. Lingering cloud cover and modest surface moisture greatly limit available buoyancy ahead of the line. With only a few hundred J/kg of MUCAPE, decreasing with eastward extent, a gradual loss in intensity is expected over the next several hours over northeastern PA and NY. Still, very strong gradient winds and flow aloft will support some potential for convective-enhanced damaging gusts through this evening. 300-400 m2/s2 of 0-3km SRH may also support the threat for a couple of brief QLCS tornadoes while the line maintains intensity. Probabilities have also be trimmed farther south over parts of the western Carolinas, GA and northern FL as the main convective band and cold front have shifted east. Some isolated thunderstorm redevelopment remains possible over parts of the Blue Ridge Mountains of western VA and into the central Carolinas where diurnal heating has steepened low-level lapse rates immediately ahead of the synoptic cold front. While confidence in severe potential is modest given meager buoyancy, the steep lapse rates could support damaging gusts or marginal hail, should more sustained convection redevelop as indicated by some CAMS. These storms may eventually shift eastward into the mid Atlantic late this afternoon and into the early evening, where low-level synoptic flow remains fairly strong. Will maintain the Slight Risk for damaging gusts and isolated tornado potential over parts of the Mid Atlantic into tonight. ..Lyons.. 03/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sun Mar 16 2025/ ...Ohio Valley into the Mid-Atlantic... A highly amplified upper trough over the MS Valley this morning will advance eastward over much of the eastern CONUS today. An embedded 100+ kt southwesterly mid-level jet and associated large-scale ascent will overspread the upper OH Valley and western Mid-Atlantic regions through this evening. The primary surface low over eastern Lower MI will develop northeastward into Ontario and Quebec through the day, while an attendant cold front sweeps eastward across the OH Valley/Mid-Atlantic through the period. Recent visible satellite imagery shows some clearing ahead of the synoptic cold front in eastern OH and western PA. Although low-level moisture will be somewhat limited, with surface dewpoints generally in the mid to upper 50s, cool mid-level temperatures will overspread the narrow warm sector this afternoon. This, combined with daytime heating, will support a narrow zone of up to 250-500 J/kg of MLCAPE just ahead of the cold front and/or pre-frontal trough, which should be sufficient for surface-based convection. Bands of low-topped thunderstorms have developed both along and just ahead of the cold front. This activity will move quickly east-northeastward across WV, western/central PA, and parts of NY through the day. With strong low/mid-level flow already in place per area VWPs, this line should pose a threat for mainly scattered damaging winds, with peak gusts perhaps reaching up to 60-70 mph. There will also be rather strong low-level shear in place, which may support some threat for a few tornadoes embedded within the line, especially if low-level flow can remain backed more to a southeasterly component. The northeastward extent of this severe wind and tornado risk into the Mid-Atlantic and NY remains unclear, as persistent cloud cover will inhibit daytime heating to some extent. Still, most guidance shows one or more lines persisting through the afternoon and evening while posing some wind threat. Severe probabilities have been adjusted northeastward across parts of the Mid-Atlantic to account for latest observational and guidance trends. ...Southeast/Carolinas... The southern portion of the highly amplified upper trough will continue eastward across the lower MS Valley and Southeast today, as an intense southerly low-level jet shifts east across north FL and the Carolinas through this evening. Ongoing pre-frontal convection has mostly weakened late this morning/early afternoon, with a couple of stronger cells persisting over southeast GA and north FL where greater low-level moisture and instability is present. Adequately enlarged low-level hodographs within a gradually destabilizing airmass (1000-1500 J/kg MLCAPE across north-central FL, with weaker instability over the coastal Carolinas) should continue to support organized convection through the afternoon and evening, before activity eventually moves offshore. Broken line segments (mainly Carolinas) and some supercells (mainly southeast GA and north FL) will pose a threat for scattered damaging winds (peak gusts up to 55-70 mph) and a few tornadoes. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0301 PM CDT Sun Mar 16 2025 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF UPSTATE NEW YORK...THE MID-ATLANTIC...AND THE SOUTHEAST... ...SUMMARY... Damaging wind and a few tornadoes remain possible through the remainder of this afternoon and evening across parts of upstate New York, the Mid-Atlantic and the Southeast. ...20z Update... The main forecast changes for 20z have been to reduce probabilities behind the squall line ongoing over PA and western NY state, and expand slightly ahead of the more persistent bowing segments over northern NY. Lingering cloud cover and modest surface moisture greatly limit available buoyancy ahead of the line. With only a few hundred J/kg of MUCAPE, decreasing with eastward extent, a gradual loss in intensity is expected over the next several hours over northeastern PA and NY. Still, very strong gradient winds and flow aloft will support some potential for convective-enhanced damaging gusts through this evening. 300-400 m2/s2 of 0-3km SRH may also support the threat for a couple of brief QLCS tornadoes while the line maintains intensity. Probabilities have also be trimmed farther south over parts of the western Carolinas, GA and northern FL as the main convective band and cold front have shifted east. Some isolated thunderstorm redevelopment remains possible over parts of the Blue Ridge Mountains of western VA and into the central Carolinas where diurnal heating has steepened low-level lapse rates immediately ahead of the synoptic cold front. While confidence in severe potential is modest given meager buoyancy, the steep lapse rates could support damaging gusts or marginal hail, should more sustained convection redevelop as indicated by some CAMS. These storms may eventually shift eastward into the mid Atlantic late this afternoon and into the early evening, where low-level synoptic flow remains fairly strong. Will maintain the Slight Risk for damaging gusts and isolated tornado potential over parts of the Mid Atlantic into tonight. ..Lyons.. 03/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sun Mar 16 2025/ ...Ohio Valley into the Mid-Atlantic... A highly amplified upper trough over the MS Valley this morning will advance eastward over much of the eastern CONUS today. An embedded 100+ kt southwesterly mid-level jet and associated large-scale ascent will overspread the upper OH Valley and western Mid-Atlantic regions through this evening. The primary surface low over eastern Lower MI will develop northeastward into Ontario and Quebec through the day, while an attendant cold front sweeps eastward across the OH Valley/Mid-Atlantic through the period. Recent visible satellite imagery shows some clearing ahead of the synoptic cold front in eastern OH and western PA. Although low-level moisture will be somewhat limited, with surface dewpoints generally in the mid to upper 50s, cool mid-level temperatures will overspread the narrow warm sector this afternoon. This, combined with daytime heating, will support a narrow zone of up to 250-500 J/kg of MLCAPE just ahead of the cold front and/or pre-frontal trough, which should be sufficient for surface-based convection. Bands of low-topped thunderstorms have developed both along and just ahead of the cold front. This activity will move quickly east-northeastward across WV, western/central PA, and parts of NY through the day. With strong low/mid-level flow already in place per area VWPs, this line should pose a threat for mainly scattered damaging winds, with peak gusts perhaps reaching up to 60-70 mph. There will also be rather strong low-level shear in place, which may support some threat for a few tornadoes embedded within the line, especially if low-level flow can remain backed more to a southeasterly component. The northeastward extent of this severe wind and tornado risk into the Mid-Atlantic and NY remains unclear, as persistent cloud cover will inhibit daytime heating to some extent. Still, most guidance shows one or more lines persisting through the afternoon and evening while posing some wind threat. Severe probabilities have been adjusted northeastward across parts of the Mid-Atlantic to account for latest observational and guidance trends. ...Southeast/Carolinas... The southern portion of the highly amplified upper trough will continue eastward across the lower MS Valley and Southeast today, as an intense southerly low-level jet shifts east across north FL and the Carolinas through this evening. Ongoing pre-frontal convection has mostly weakened late this morning/early afternoon, with a couple of stronger cells persisting over southeast GA and north FL where greater low-level moisture and instability is present. Adequately enlarged low-level hodographs within a gradually destabilizing airmass (1000-1500 J/kg MLCAPE across north-central FL, with weaker instability over the coastal Carolinas) should continue to support organized convection through the afternoon and evening, before activity eventually moves offshore. Broken line segments (mainly Carolinas) and some supercells (mainly southeast GA and north FL) will pose a threat for scattered damaging winds (peak gusts up to 55-70 mph) and a few tornadoes. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0301 PM CDT Sun Mar 16 2025 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF UPSTATE NEW YORK...THE MID-ATLANTIC...AND THE SOUTHEAST... ...SUMMARY... Damaging wind and a few tornadoes remain possible through the remainder of this afternoon and evening across parts of upstate New York, the Mid-Atlantic and the Southeast. ...20z Update... The main forecast changes for 20z have been to reduce probabilities behind the squall line ongoing over PA and western NY state, and expand slightly ahead of the more persistent bowing segments over northern NY. Lingering cloud cover and modest surface moisture greatly limit available buoyancy ahead of the line. With only a few hundred J/kg of MUCAPE, decreasing with eastward extent, a gradual loss in intensity is expected over the next several hours over northeastern PA and NY. Still, very strong gradient winds and flow aloft will support some potential for convective-enhanced damaging gusts through this evening. 300-400 m2/s2 of 0-3km SRH may also support the threat for a couple of brief QLCS tornadoes while the line maintains intensity. Probabilities have also be trimmed farther south over parts of the western Carolinas, GA and northern FL as the main convective band and cold front have shifted east. Some isolated thunderstorm redevelopment remains possible over parts of the Blue Ridge Mountains of western VA and into the central Carolinas where diurnal heating has steepened low-level lapse rates immediately ahead of the synoptic cold front. While confidence in severe potential is modest given meager buoyancy, the steep lapse rates could support damaging gusts or marginal hail, should more sustained convection redevelop as indicated by some CAMS. These storms may eventually shift eastward into the mid Atlantic late this afternoon and into the early evening, where low-level synoptic flow remains fairly strong. Will maintain the Slight Risk for damaging gusts and isolated tornado potential over parts of the Mid Atlantic into tonight. ..Lyons.. 03/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sun Mar 16 2025/ ...Ohio Valley into the Mid-Atlantic... A highly amplified upper trough over the MS Valley this morning will advance eastward over much of the eastern CONUS today. An embedded 100+ kt southwesterly mid-level jet and associated large-scale ascent will overspread the upper OH Valley and western Mid-Atlantic regions through this evening. The primary surface low over eastern Lower MI will develop northeastward into Ontario and Quebec through the day, while an attendant cold front sweeps eastward across the OH Valley/Mid-Atlantic through the period. Recent visible satellite imagery shows some clearing ahead of the synoptic cold front in eastern OH and western PA. Although low-level moisture will be somewhat limited, with surface dewpoints generally in the mid to upper 50s, cool mid-level temperatures will overspread the narrow warm sector this afternoon. This, combined with daytime heating, will support a narrow zone of up to 250-500 J/kg of MLCAPE just ahead of the cold front and/or pre-frontal trough, which should be sufficient for surface-based convection. Bands of low-topped thunderstorms have developed both along and just ahead of the cold front. This activity will move quickly east-northeastward across WV, western/central PA, and parts of NY through the day. With strong low/mid-level flow already in place per area VWPs, this line should pose a threat for mainly scattered damaging winds, with peak gusts perhaps reaching up to 60-70 mph. There will also be rather strong low-level shear in place, which may support some threat for a few tornadoes embedded within the line, especially if low-level flow can remain backed more to a southeasterly component. The northeastward extent of this severe wind and tornado risk into the Mid-Atlantic and NY remains unclear, as persistent cloud cover will inhibit daytime heating to some extent. Still, most guidance shows one or more lines persisting through the afternoon and evening while posing some wind threat. Severe probabilities have been adjusted northeastward across parts of the Mid-Atlantic to account for latest observational and guidance trends. ...Southeast/Carolinas... The southern portion of the highly amplified upper trough will continue eastward across the lower MS Valley and Southeast today, as an intense southerly low-level jet shifts east across north FL and the Carolinas through this evening. Ongoing pre-frontal convection has mostly weakened late this morning/early afternoon, with a couple of stronger cells persisting over southeast GA and north FL where greater low-level moisture and instability is present. Adequately enlarged low-level hodographs within a gradually destabilizing airmass (1000-1500 J/kg MLCAPE across north-central FL, with weaker instability over the coastal Carolinas) should continue to support organized convection through the afternoon and evening, before activity eventually moves offshore. Broken line segments (mainly Carolinas) and some supercells (mainly southeast GA and north FL) will pose a threat for scattered damaging winds (peak gusts up to 55-70 mph) and a few tornadoes. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0301 PM CDT Sun Mar 16 2025 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF UPSTATE NEW YORK...THE MID-ATLANTIC...AND THE SOUTHEAST... ...SUMMARY... Damaging wind and a few tornadoes remain possible through the remainder of this afternoon and evening across parts of upstate New York, the Mid-Atlantic and the Southeast. ...20z Update... The main forecast changes for 20z have been to reduce probabilities behind the squall line ongoing over PA and western NY state, and expand slightly ahead of the more persistent bowing segments over northern NY. Lingering cloud cover and modest surface moisture greatly limit available buoyancy ahead of the line. With only a few hundred J/kg of MUCAPE, decreasing with eastward extent, a gradual loss in intensity is expected over the next several hours over northeastern PA and NY. Still, very strong gradient winds and flow aloft will support some potential for convective-enhanced damaging gusts through this evening. 300-400 m2/s2 of 0-3km SRH may also support the threat for a couple of brief QLCS tornadoes while the line maintains intensity. Probabilities have also be trimmed farther south over parts of the western Carolinas, GA and northern FL as the main convective band and cold front have shifted east. Some isolated thunderstorm redevelopment remains possible over parts of the Blue Ridge Mountains of western VA and into the central Carolinas where diurnal heating has steepened low-level lapse rates immediately ahead of the synoptic cold front. While confidence in severe potential is modest given meager buoyancy, the steep lapse rates could support damaging gusts or marginal hail, should more sustained convection redevelop as indicated by some CAMS. These storms may eventually shift eastward into the mid Atlantic late this afternoon and into the early evening, where low-level synoptic flow remains fairly strong. Will maintain the Slight Risk for damaging gusts and isolated tornado potential over parts of the Mid Atlantic into tonight. ..Lyons.. 03/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sun Mar 16 2025/ ...Ohio Valley into the Mid-Atlantic... A highly amplified upper trough over the MS Valley this morning will advance eastward over much of the eastern CONUS today. An embedded 100+ kt southwesterly mid-level jet and associated large-scale ascent will overspread the upper OH Valley and western Mid-Atlantic regions through this evening. The primary surface low over eastern Lower MI will develop northeastward into Ontario and Quebec through the day, while an attendant cold front sweeps eastward across the OH Valley/Mid-Atlantic through the period. Recent visible satellite imagery shows some clearing ahead of the synoptic cold front in eastern OH and western PA. Although low-level moisture will be somewhat limited, with surface dewpoints generally in the mid to upper 50s, cool mid-level temperatures will overspread the narrow warm sector this afternoon. This, combined with daytime heating, will support a narrow zone of up to 250-500 J/kg of MLCAPE just ahead of the cold front and/or pre-frontal trough, which should be sufficient for surface-based convection. Bands of low-topped thunderstorms have developed both along and just ahead of the cold front. This activity will move quickly east-northeastward across WV, western/central PA, and parts of NY through the day. With strong low/mid-level flow already in place per area VWPs, this line should pose a threat for mainly scattered damaging winds, with peak gusts perhaps reaching up to 60-70 mph. There will also be rather strong low-level shear in place, which may support some threat for a few tornadoes embedded within the line, especially if low-level flow can remain backed more to a southeasterly component. The northeastward extent of this severe wind and tornado risk into the Mid-Atlantic and NY remains unclear, as persistent cloud cover will inhibit daytime heating to some extent. Still, most guidance shows one or more lines persisting through the afternoon and evening while posing some wind threat. Severe probabilities have been adjusted northeastward across parts of the Mid-Atlantic to account for latest observational and guidance trends. ...Southeast/Carolinas... The southern portion of the highly amplified upper trough will continue eastward across the lower MS Valley and Southeast today, as an intense southerly low-level jet shifts east across north FL and the Carolinas through this evening. Ongoing pre-frontal convection has mostly weakened late this morning/early afternoon, with a couple of stronger cells persisting over southeast GA and north FL where greater low-level moisture and instability is present. Adequately enlarged low-level hodographs within a gradually destabilizing airmass (1000-1500 J/kg MLCAPE across north-central FL, with weaker instability over the coastal Carolinas) should continue to support organized convection through the afternoon and evening, before activity eventually moves offshore. Broken line segments (mainly Carolinas) and some supercells (mainly southeast GA and north FL) will pose a threat for scattered damaging winds (peak gusts up to 55-70 mph) and a few tornadoes. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0301 PM CDT Sun Mar 16 2025 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF UPSTATE NEW YORK...THE MID-ATLANTIC...AND THE SOUTHEAST... ...SUMMARY... Damaging wind and a few tornadoes remain possible through the remainder of this afternoon and evening across parts of upstate New York, the Mid-Atlantic and the Southeast. ...20z Update... The main forecast changes for 20z have been to reduce probabilities behind the squall line ongoing over PA and western NY state, and expand slightly ahead of the more persistent bowing segments over northern NY. Lingering cloud cover and modest surface moisture greatly limit available buoyancy ahead of the line. With only a few hundred J/kg of MUCAPE, decreasing with eastward extent, a gradual loss in intensity is expected over the next several hours over northeastern PA and NY. Still, very strong gradient winds and flow aloft will support some potential for convective-enhanced damaging gusts through this evening. 300-400 m2/s2 of 0-3km SRH may also support the threat for a couple of brief QLCS tornadoes while the line maintains intensity. Probabilities have also be trimmed farther south over parts of the western Carolinas, GA and northern FL as the main convective band and cold front have shifted east. Some isolated thunderstorm redevelopment remains possible over parts of the Blue Ridge Mountains of western VA and into the central Carolinas where diurnal heating has steepened low-level lapse rates immediately ahead of the synoptic cold front. While confidence in severe potential is modest given meager buoyancy, the steep lapse rates could support damaging gusts or marginal hail, should more sustained convection redevelop as indicated by some CAMS. These storms may eventually shift eastward into the mid Atlantic late this afternoon and into the early evening, where low-level synoptic flow remains fairly strong. Will maintain the Slight Risk for damaging gusts and isolated tornado potential over parts of the Mid Atlantic into tonight. ..Lyons.. 03/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sun Mar 16 2025/ ...Ohio Valley into the Mid-Atlantic... A highly amplified upper trough over the MS Valley this morning will advance eastward over much of the eastern CONUS today. An embedded 100+ kt southwesterly mid-level jet and associated large-scale ascent will overspread the upper OH Valley and western Mid-Atlantic regions through this evening. The primary surface low over eastern Lower MI will develop northeastward into Ontario and Quebec through the day, while an attendant cold front sweeps eastward across the OH Valley/Mid-Atlantic through the period. Recent visible satellite imagery shows some clearing ahead of the synoptic cold front in eastern OH and western PA. Although low-level moisture will be somewhat limited, with surface dewpoints generally in the mid to upper 50s, cool mid-level temperatures will overspread the narrow warm sector this afternoon. This, combined with daytime heating, will support a narrow zone of up to 250-500 J/kg of MLCAPE just ahead of the cold front and/or pre-frontal trough, which should be sufficient for surface-based convection. Bands of low-topped thunderstorms have developed both along and just ahead of the cold front. This activity will move quickly east-northeastward across WV, western/central PA, and parts of NY through the day. With strong low/mid-level flow already in place per area VWPs, this line should pose a threat for mainly scattered damaging winds, with peak gusts perhaps reaching up to 60-70 mph. There will also be rather strong low-level shear in place, which may support some threat for a few tornadoes embedded within the line, especially if low-level flow can remain backed more to a southeasterly component. The northeastward extent of this severe wind and tornado risk into the Mid-Atlantic and NY remains unclear, as persistent cloud cover will inhibit daytime heating to some extent. Still, most guidance shows one or more lines persisting through the afternoon and evening while posing some wind threat. Severe probabilities have been adjusted northeastward across parts of the Mid-Atlantic to account for latest observational and guidance trends. ...Southeast/Carolinas... The southern portion of the highly amplified upper trough will continue eastward across the lower MS Valley and Southeast today, as an intense southerly low-level jet shifts east across north FL and the Carolinas through this evening. Ongoing pre-frontal convection has mostly weakened late this morning/early afternoon, with a couple of stronger cells persisting over southeast GA and north FL where greater low-level moisture and instability is present. Adequately enlarged low-level hodographs within a gradually destabilizing airmass (1000-1500 J/kg MLCAPE across north-central FL, with weaker instability over the coastal Carolinas) should continue to support organized convection through the afternoon and evening, before activity eventually moves offshore. Broken line segments (mainly Carolinas) and some supercells (mainly southeast GA and north FL) will pose a threat for scattered damaging winds (peak gusts up to 55-70 mph) and a few tornadoes. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0301 PM CDT Sun Mar 16 2025 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF UPSTATE NEW YORK...THE MID-ATLANTIC...AND THE SOUTHEAST... ...SUMMARY... Damaging wind and a few tornadoes remain possible through the remainder of this afternoon and evening across parts of upstate New York, the Mid-Atlantic and the Southeast. ...20z Update... The main forecast changes for 20z have been to reduce probabilities behind the squall line ongoing over PA and western NY state, and expand slightly ahead of the more persistent bowing segments over northern NY. Lingering cloud cover and modest surface moisture greatly limit available buoyancy ahead of the line. With only a few hundred J/kg of MUCAPE, decreasing with eastward extent, a gradual loss in intensity is expected over the next several hours over northeastern PA and NY. Still, very strong gradient winds and flow aloft will support some potential for convective-enhanced damaging gusts through this evening. 300-400 m2/s2 of 0-3km SRH may also support the threat for a couple of brief QLCS tornadoes while the line maintains intensity. Probabilities have also be trimmed farther south over parts of the western Carolinas, GA and northern FL as the main convective band and cold front have shifted east. Some isolated thunderstorm redevelopment remains possible over parts of the Blue Ridge Mountains of western VA and into the central Carolinas where diurnal heating has steepened low-level lapse rates immediately ahead of the synoptic cold front. While confidence in severe potential is modest given meager buoyancy, the steep lapse rates could support damaging gusts or marginal hail, should more sustained convection redevelop as indicated by some CAMS. These storms may eventually shift eastward into the mid Atlantic late this afternoon and into the early evening, where low-level synoptic flow remains fairly strong. Will maintain the Slight Risk for damaging gusts and isolated tornado potential over parts of the Mid Atlantic into tonight. ..Lyons.. 03/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sun Mar 16 2025/ ...Ohio Valley into the Mid-Atlantic... A highly amplified upper trough over the MS Valley this morning will advance eastward over much of the eastern CONUS today. An embedded 100+ kt southwesterly mid-level jet and associated large-scale ascent will overspread the upper OH Valley and western Mid-Atlantic regions through this evening. The primary surface low over eastern Lower MI will develop northeastward into Ontario and Quebec through the day, while an attendant cold front sweeps eastward across the OH Valley/Mid-Atlantic through the period. Recent visible satellite imagery shows some clearing ahead of the synoptic cold front in eastern OH and western PA. Although low-level moisture will be somewhat limited, with surface dewpoints generally in the mid to upper 50s, cool mid-level temperatures will overspread the narrow warm sector this afternoon. This, combined with daytime heating, will support a narrow zone of up to 250-500 J/kg of MLCAPE just ahead of the cold front and/or pre-frontal trough, which should be sufficient for surface-based convection. Bands of low-topped thunderstorms have developed both along and just ahead of the cold front. This activity will move quickly east-northeastward across WV, western/central PA, and parts of NY through the day. With strong low/mid-level flow already in place per area VWPs, this line should pose a threat for mainly scattered damaging winds, with peak gusts perhaps reaching up to 60-70 mph. There will also be rather strong low-level shear in place, which may support some threat for a few tornadoes embedded within the line, especially if low-level flow can remain backed more to a southeasterly component. The northeastward extent of this severe wind and tornado risk into the Mid-Atlantic and NY remains unclear, as persistent cloud cover will inhibit daytime heating to some extent. Still, most guidance shows one or more lines persisting through the afternoon and evening while posing some wind threat. Severe probabilities have been adjusted northeastward across parts of the Mid-Atlantic to account for latest observational and guidance trends. ...Southeast/Carolinas... The southern portion of the highly amplified upper trough will continue eastward across the lower MS Valley and Southeast today, as an intense southerly low-level jet shifts east across north FL and the Carolinas through this evening. Ongoing pre-frontal convection has mostly weakened late this morning/early afternoon, with a couple of stronger cells persisting over southeast GA and north FL where greater low-level moisture and instability is present. Adequately enlarged low-level hodographs within a gradually destabilizing airmass (1000-1500 J/kg MLCAPE across north-central FL, with weaker instability over the coastal Carolinas) should continue to support organized convection through the afternoon and evening, before activity eventually moves offshore. Broken line segments (mainly Carolinas) and some supercells (mainly southeast GA and north FL) will pose a threat for scattered damaging winds (peak gusts up to 55-70 mph) and a few tornadoes. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0301 PM CDT Sun Mar 16 2025 Valid 162000Z - 171200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF UPSTATE NEW YORK...THE MID-ATLANTIC...AND THE SOUTHEAST... ...SUMMARY... Damaging wind and a few tornadoes remain possible through the remainder of this afternoon and evening across parts of upstate New York, the Mid-Atlantic and the Southeast. ...20z Update... The main forecast changes for 20z have been to reduce probabilities behind the squall line ongoing over PA and western NY state, and expand slightly ahead of the more persistent bowing segments over northern NY. Lingering cloud cover and modest surface moisture greatly limit available buoyancy ahead of the line. With only a few hundred J/kg of MUCAPE, decreasing with eastward extent, a gradual loss in intensity is expected over the next several hours over northeastern PA and NY. Still, very strong gradient winds and flow aloft will support some potential for convective-enhanced damaging gusts through this evening. 300-400 m2/s2 of 0-3km SRH may also support the threat for a couple of brief QLCS tornadoes while the line maintains intensity. Probabilities have also be trimmed farther south over parts of the western Carolinas, GA and northern FL as the main convective band and cold front have shifted east. Some isolated thunderstorm redevelopment remains possible over parts of the Blue Ridge Mountains of western VA and into the central Carolinas where diurnal heating has steepened low-level lapse rates immediately ahead of the synoptic cold front. While confidence in severe potential is modest given meager buoyancy, the steep lapse rates could support damaging gusts or marginal hail, should more sustained convection redevelop as indicated by some CAMS. These storms may eventually shift eastward into the mid Atlantic late this afternoon and into the early evening, where low-level synoptic flow remains fairly strong. Will maintain the Slight Risk for damaging gusts and isolated tornado potential over parts of the Mid Atlantic into tonight. ..Lyons.. 03/16/2025 .PREV DISCUSSION... /ISSUED 1128 AM CDT Sun Mar 16 2025/ ...Ohio Valley into the Mid-Atlantic... A highly amplified upper trough over the MS Valley this morning will advance eastward over much of the eastern CONUS today. An embedded 100+ kt southwesterly mid-level jet and associated large-scale ascent will overspread the upper OH Valley and western Mid-Atlantic regions through this evening. The primary surface low over eastern Lower MI will develop northeastward into Ontario and Quebec through the day, while an attendant cold front sweeps eastward across the OH Valley/Mid-Atlantic through the period. Recent visible satellite imagery shows some clearing ahead of the synoptic cold front in eastern OH and western PA. Although low-level moisture will be somewhat limited, with surface dewpoints generally in the mid to upper 50s, cool mid-level temperatures will overspread the narrow warm sector this afternoon. This, combined with daytime heating, will support a narrow zone of up to 250-500 J/kg of MLCAPE just ahead of the cold front and/or pre-frontal trough, which should be sufficient for surface-based convection. Bands of low-topped thunderstorms have developed both along and just ahead of the cold front. This activity will move quickly east-northeastward across WV, western/central PA, and parts of NY through the day. With strong low/mid-level flow already in place per area VWPs, this line should pose a threat for mainly scattered damaging winds, with peak gusts perhaps reaching up to 60-70 mph. There will also be rather strong low-level shear in place, which may support some threat for a few tornadoes embedded within the line, especially if low-level flow can remain backed more to a southeasterly component. The northeastward extent of this severe wind and tornado risk into the Mid-Atlantic and NY remains unclear, as persistent cloud cover will inhibit daytime heating to some extent. Still, most guidance shows one or more lines persisting through the afternoon and evening while posing some wind threat. Severe probabilities have been adjusted northeastward across parts of the Mid-Atlantic to account for latest observational and guidance trends. ...Southeast/Carolinas... The southern portion of the highly amplified upper trough will continue eastward across the lower MS Valley and Southeast today, as an intense southerly low-level jet shifts east across north FL and the Carolinas through this evening. Ongoing pre-frontal convection has mostly weakened late this morning/early afternoon, with a couple of stronger cells persisting over southeast GA and north FL where greater low-level moisture and instability is present. Adequately enlarged low-level hodographs within a gradually destabilizing airmass (1000-1500 J/kg MLCAPE across north-central FL, with weaker instability over the coastal Carolinas) should continue to support organized convection through the afternoon and evening, before activity eventually moves offshore. Broken line segments (mainly Carolinas) and some supercells (mainly southeast GA and north FL) will pose a threat for scattered damaging winds (peak gusts up to 55-70 mph) and a few tornadoes. Read more