Aggregator

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0428 PM CDT Sat Jun 29 2024 Valid 011200Z - 071200Z While initially limited in scope, fire-weather concerns appear likely to increase through the extended forecast period as a strong ridge of high pressure builds over the West Coast. Very hot temperatures and dry surface conditions should gradually increase fire danger over much of the West, as stronger northwest flow over the Great Basin will continue through mid to late week. Ridge breakdown is expected late in the forecast period as early as next weekend. Uncertainty on the character of the pattern following this transition remains high, but dry and breezy conditions are possible through much of next week and into next weekend across the interior Northwest and Great Basin ...Interior Pac. Northwest & northern Great Basin... As the ridge builds quickly this weekend, enhanced flow aloft will develop along the eastern periphery as a weak trough moves south out of Canada. At the surface, a weak cold front should move south into the Great Basin, enhancing surface winds and the chance for isolated thunderstorms over parts of OR, NV, UT, and ID. Isolated critical fire-weather conditions could occur D3/Mon as the gusty winds and low RH spread through the northern Great Basin and Snake River Valley. Behind the front, dry northwesterly surface flow should continue through the first part of the week as the ridge aloft intensifies. Very warm temperatures should allow for an increase in fire danger indices through the week before another shortwave trough and cold front pass along the eastern portion of the ridge D5/Wed and D6/Thur. Gusty surface winds are likely over portions of the northern Great Basin and southern ID along, with very dry surface conditions. With increasingly dry fuels, critical fire-weather conditions may develop. At the end of the forecast period, most medium-range guidance shows the upper-ridge breaking down ahead of a trough moving into the Pacific Northwest. It remains unclear exactly how this transition will evolve, with some guidance showing an increase in showers and thunderstorms, while others show a more substantial increase in hot, dry and windy conditions with trough passage. Regardless of the outcome, an increase in fire-weather potential is very likely, owing to the antecedent hot and dry conditions beneath the weakening ridge. ...Northern CA... Under the ridge aloft, a thermal trough is likely to extend from the Desert Southwest through northern CA, leading to poor RH recovery and occasional gusty winds from early to mid week next week. Gusty northerly winds are possible in portions of northern CA, especially in/around the Sacramento Valley. Drying fuels and the increase in temperatures are likely to support at least some isolated fire-weather risk through the next several days, though the exact coverage and duration are currently unclear. ..Lyons.. 06/29/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0428 PM CDT Sat Jun 29 2024 Valid 011200Z - 071200Z While initially limited in scope, fire-weather concerns appear likely to increase through the extended forecast period as a strong ridge of high pressure builds over the West Coast. Very hot temperatures and dry surface conditions should gradually increase fire danger over much of the West, as stronger northwest flow over the Great Basin will continue through mid to late week. Ridge breakdown is expected late in the forecast period as early as next weekend. Uncertainty on the character of the pattern following this transition remains high, but dry and breezy conditions are possible through much of next week and into next weekend across the interior Northwest and Great Basin ...Interior Pac. Northwest & northern Great Basin... As the ridge builds quickly this weekend, enhanced flow aloft will develop along the eastern periphery as a weak trough moves south out of Canada. At the surface, a weak cold front should move south into the Great Basin, enhancing surface winds and the chance for isolated thunderstorms over parts of OR, NV, UT, and ID. Isolated critical fire-weather conditions could occur D3/Mon as the gusty winds and low RH spread through the northern Great Basin and Snake River Valley. Behind the front, dry northwesterly surface flow should continue through the first part of the week as the ridge aloft intensifies. Very warm temperatures should allow for an increase in fire danger indices through the week before another shortwave trough and cold front pass along the eastern portion of the ridge D5/Wed and D6/Thur. Gusty surface winds are likely over portions of the northern Great Basin and southern ID along, with very dry surface conditions. With increasingly dry fuels, critical fire-weather conditions may develop. At the end of the forecast period, most medium-range guidance shows the upper-ridge breaking down ahead of a trough moving into the Pacific Northwest. It remains unclear exactly how this transition will evolve, with some guidance showing an increase in showers and thunderstorms, while others show a more substantial increase in hot, dry and windy conditions with trough passage. Regardless of the outcome, an increase in fire-weather potential is very likely, owing to the antecedent hot and dry conditions beneath the weakening ridge. ...Northern CA... Under the ridge aloft, a thermal trough is likely to extend from the Desert Southwest through northern CA, leading to poor RH recovery and occasional gusty winds from early to mid week next week. Gusty northerly winds are possible in portions of northern CA, especially in/around the Sacramento Valley. Drying fuels and the increase in temperatures are likely to support at least some isolated fire-weather risk through the next several days, though the exact coverage and duration are currently unclear. ..Lyons.. 06/29/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0485 Status Updates
STATUS FOR WATCH 0485 HAS NOT BEEN ISSUED YET Read more

WW 0484 Status Updates
STATUS FOR WATCH 0484 HAS NOT BEEN ISSUED YET Read more

MD 1475 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF NORTHERN WV INTO MD AND NORTHERN VA
Mesoscale Discussion 1475 NWS Storm Prediction Center Norman OK 0230 PM CDT Sat Jun 29 2024 Areas affected...portions of northern WV into MD and northern VA Concerning...Severe potential...Watch possible Valid 291930Z - 292100Z Probability of Watch Issuance...40 percent SUMMARY...Isolated strong storms may produce locally damaging gusts into early evening. Area is being monitored for possible watch issuance. DISCUSSION...Isolated thunderstorms are developing within weak to moderate instability and modest vertical shear. A narrow corridor may exist where more favorable shear overlaps with stronger instability and steep low-level lapse rates. A few strong to isolated severe storms capable of mainly damaging gusts (45-60 mph) will be possible into early evening. While spatial/temporal extent of the risk is expected to remain limited, a small severe thunderstorm watch is being considered. ..Leitman/Gleason.. 06/29/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LWX...PBZ...RLX... LAT...LON 39558101 39717857 39717717 39457695 39077717 38997762 38877915 38838009 38878085 39058157 39358145 39528123 39558101 Read more

WW 0482 Status Updates
STATUS REPORT ON WW 482 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 NW ZZV TO 20 SW DUJ TO 30 SSE ELM. ..LEITMAN..06/29/24 ATTN...WFO...PBZ...CLE...CTP... STATUS REPORT FOR WT 482 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS OHC013-019-031-059-067-081-111-119-121-157-292140- OH . OHIO COUNTIES INCLUDED ARE BELMONT CARROLL COSHOCTON GUERNSEY HARRISON JEFFERSON MONROE MUSKINGUM NOBLE TUSCARAWAS PAC003-005-007-009-013-021-027-033-035-037-051-055-057-059-061- 063-067-081-087-093-097-099-109-111-113-119-125-129-292140- PA . PENNSYLVANIA COUNTIES INCLUDED ARE ALLEGHENY ARMSTRONG BEAVER BEDFORD BLAIR CAMBRIA CENTRE CLEARFIELD CLINTON COLUMBIA FAYETTE FRANKLIN FULTON GREENE HUNTINGDON INDIANA JUNIATA LYCOMING MIFFLIN MONTOUR NORTHUMBERLAND PERRY SNYDER SOMERSET Read more

WW 0483 Status Updates
STATUS FOR WATCH 0483 HAS NOT BEEN ISSUED YET Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sat Jun 29 2024 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY/MID-ATLANTIC...OZARKS VICINITY...AND THE SOUTHERN/CENTRAL HIGH PLAINS...... ...SUMMARY... Damaging thunderstorm gusts and a few tornadoes appear possible today over parts of the Lower Great Lakes to upper Ohio Valley and Mid-Atlantic. Severe gusts may also be focused this afternoon and evening over the Ozarks vicinity, and the Raton Mesa and adjacent south-central High Plains. ...20Z Update... Extended the Slight Risk westward toward Indiana due to ongoing severe cluster of storms, and an extremely moist air mass ahead of it. GPS PWAT values exceed 2.25" over much of the area, and low-level lapse rates continue to steepen just south, which should support corridors of damaging wind. Farther east, tornado watch 482 remains in effect from eastern OH into PA and toward the NY border. Scattered storms persist, and southwesterly low-level winds will aid theta-e advection into the region. In addition, 0-1 km SRH remains favorable at over 150 m2/s2 from OH to central PA, with stronger values up to 300 m2/s2 into NY where the air mass is less unstable. As such, stronger cells developing this afternoon may acquire rotation with tornado potential. Overnight, the strong shortwave trough will move across southwest Ontario, skirting the Lake Ontario area and into northern NY. Given the strength of the trough, and forecast theta-e advection around 850 mb ahead of the system, additional nocturnal storms producing wind or hail will be possible. ..Jewell.. 06/29/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Jun 29 2024/ ...Lower Great Lakes and Upper Ohio Valley into the Mid-Atlantic... A loosely organized band of convection is ongoing across parts of northern/central OH. As an upper trough over the Great Lakes and eastern Canada continues to move eastward through the period, current expectations are for convection to gradually increase in coverage and intensity this afternoon across eastern OH into western PA. Recent visible satellite imagery shows substantial cloudiness across this area, which should hinder diurnal heating to some extent. Still, even modest heating of the rather moist low-level airmass should support at least weak instability by late this afternoon. Low-level and deep-layer shear appear sufficiently strong for a mix of multicells and supercells. Damaging winds will be a concern with any bowing cluster that can form and spread eastward across parts of the Mid-Atlantic through the afternoon/evening. A couple of tornadoes may also occur with any sustained supercell or embedded QLCS circulations. See Mesoscale Discussion 1472 for more details on the short-term severe threat across OH into northern WV and western PA. There also appears to be some chance for additional convection to develop along the cold front across IL/IN this afternoon, perhaps associated with a remnant MCV over eastern MO. Substantial cloudiness is present across much of this region ahead of the front. But, any thunderstorms that can form may be capable of producing isolated hail and/or strong to damaging winds. Considered including this area in a Slight Risk, but confidence remains low in robust convection persisting with eastward extent into the OH Valley in the wake of earlier thunderstorm activity. ...Ozarks... A Slight Risk for damaging winds has been introduced for southern MO, northeast OK, and vicinity. Outflow from earlier convection, along with the slowly sagging cold front, should continue southward across these areas through late afternoon while also providing a focus for additional convection. Moderate to strong instability is forecast to develop this afternoon in a narrow zone along/ahead of the front. While deep-layer shear should remain fairly modest, most 12Z guidance shows a greater concentration of robust convection developing across southern MO and vicinity late this afternoon and early evening. Loosely organized clusters capable of producing mainly damaging winds should spread generally east-southeastward through the evening. Isolated hail may also occur. ...Southern/Central High Plains... No changes have been made to the Slight Risk across the southern/central High Plains. Scattered thunderstorms are expected to develop during the late afternoon and evening in a weak post-frontal, upslope flow regime. Generally upper 50s to low 60s surface dewpoints and steep mid-level lapse rates will support a narrow corridor of moderate instability by late afternoon. While mid-level flow is expected to remain weak, vertically veering wind profiles with height through mid/upper levels will support sufficient deep shear for transient, slow-moving supercells and loosely organized clusters developing off the higher terrain of southern CO and northern NM. Occasional severe gusts appear possible with this activity as low-level lapse rates become steepened through diurnal heating. Some hail may also occur with the strongest cores. ...Michigan... Despite veered low-level winds ahead of the cold front and weak mid-level lapse rates, boundary-layer heating should yield a plume of weak instability, with MLCAPE around 500-1000 J/kg by this afternoon. Strong speed shear will support hodograph elongation. This may yield a supercell or two capable of isolated severe hail and locally strong wind gusts in the eastern U.P. into Lower MI. But, overall coverage of strong/severe thunderstorms is expected to remain rather limited across this area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sat Jun 29 2024 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY/MID-ATLANTIC...OZARKS VICINITY...AND THE SOUTHERN/CENTRAL HIGH PLAINS...... ...SUMMARY... Damaging thunderstorm gusts and a few tornadoes appear possible today over parts of the Lower Great Lakes to upper Ohio Valley and Mid-Atlantic. Severe gusts may also be focused this afternoon and evening over the Ozarks vicinity, and the Raton Mesa and adjacent south-central High Plains. ...20Z Update... Extended the Slight Risk westward toward Indiana due to ongoing severe cluster of storms, and an extremely moist air mass ahead of it. GPS PWAT values exceed 2.25" over much of the area, and low-level lapse rates continue to steepen just south, which should support corridors of damaging wind. Farther east, tornado watch 482 remains in effect from eastern OH into PA and toward the NY border. Scattered storms persist, and southwesterly low-level winds will aid theta-e advection into the region. In addition, 0-1 km SRH remains favorable at over 150 m2/s2 from OH to central PA, with stronger values up to 300 m2/s2 into NY where the air mass is less unstable. As such, stronger cells developing this afternoon may acquire rotation with tornado potential. Overnight, the strong shortwave trough will move across southwest Ontario, skirting the Lake Ontario area and into northern NY. Given the strength of the trough, and forecast theta-e advection around 850 mb ahead of the system, additional nocturnal storms producing wind or hail will be possible. ..Jewell.. 06/29/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Jun 29 2024/ ...Lower Great Lakes and Upper Ohio Valley into the Mid-Atlantic... A loosely organized band of convection is ongoing across parts of northern/central OH. As an upper trough over the Great Lakes and eastern Canada continues to move eastward through the period, current expectations are for convection to gradually increase in coverage and intensity this afternoon across eastern OH into western PA. Recent visible satellite imagery shows substantial cloudiness across this area, which should hinder diurnal heating to some extent. Still, even modest heating of the rather moist low-level airmass should support at least weak instability by late this afternoon. Low-level and deep-layer shear appear sufficiently strong for a mix of multicells and supercells. Damaging winds will be a concern with any bowing cluster that can form and spread eastward across parts of the Mid-Atlantic through the afternoon/evening. A couple of tornadoes may also occur with any sustained supercell or embedded QLCS circulations. See Mesoscale Discussion 1472 for more details on the short-term severe threat across OH into northern WV and western PA. There also appears to be some chance for additional convection to develop along the cold front across IL/IN this afternoon, perhaps associated with a remnant MCV over eastern MO. Substantial cloudiness is present across much of this region ahead of the front. But, any thunderstorms that can form may be capable of producing isolated hail and/or strong to damaging winds. Considered including this area in a Slight Risk, but confidence remains low in robust convection persisting with eastward extent into the OH Valley in the wake of earlier thunderstorm activity. ...Ozarks... A Slight Risk for damaging winds has been introduced for southern MO, northeast OK, and vicinity. Outflow from earlier convection, along with the slowly sagging cold front, should continue southward across these areas through late afternoon while also providing a focus for additional convection. Moderate to strong instability is forecast to develop this afternoon in a narrow zone along/ahead of the front. While deep-layer shear should remain fairly modest, most 12Z guidance shows a greater concentration of robust convection developing across southern MO and vicinity late this afternoon and early evening. Loosely organized clusters capable of producing mainly damaging winds should spread generally east-southeastward through the evening. Isolated hail may also occur. ...Southern/Central High Plains... No changes have been made to the Slight Risk across the southern/central High Plains. Scattered thunderstorms are expected to develop during the late afternoon and evening in a weak post-frontal, upslope flow regime. Generally upper 50s to low 60s surface dewpoints and steep mid-level lapse rates will support a narrow corridor of moderate instability by late afternoon. While mid-level flow is expected to remain weak, vertically veering wind profiles with height through mid/upper levels will support sufficient deep shear for transient, slow-moving supercells and loosely organized clusters developing off the higher terrain of southern CO and northern NM. Occasional severe gusts appear possible with this activity as low-level lapse rates become steepened through diurnal heating. Some hail may also occur with the strongest cores. ...Michigan... Despite veered low-level winds ahead of the cold front and weak mid-level lapse rates, boundary-layer heating should yield a plume of weak instability, with MLCAPE around 500-1000 J/kg by this afternoon. Strong speed shear will support hodograph elongation. This may yield a supercell or two capable of isolated severe hail and locally strong wind gusts in the eastern U.P. into Lower MI. But, overall coverage of strong/severe thunderstorms is expected to remain rather limited across this area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sat Jun 29 2024 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY/MID-ATLANTIC...OZARKS VICINITY...AND THE SOUTHERN/CENTRAL HIGH PLAINS...... ...SUMMARY... Damaging thunderstorm gusts and a few tornadoes appear possible today over parts of the Lower Great Lakes to upper Ohio Valley and Mid-Atlantic. Severe gusts may also be focused this afternoon and evening over the Ozarks vicinity, and the Raton Mesa and adjacent south-central High Plains. ...20Z Update... Extended the Slight Risk westward toward Indiana due to ongoing severe cluster of storms, and an extremely moist air mass ahead of it. GPS PWAT values exceed 2.25" over much of the area, and low-level lapse rates continue to steepen just south, which should support corridors of damaging wind. Farther east, tornado watch 482 remains in effect from eastern OH into PA and toward the NY border. Scattered storms persist, and southwesterly low-level winds will aid theta-e advection into the region. In addition, 0-1 km SRH remains favorable at over 150 m2/s2 from OH to central PA, with stronger values up to 300 m2/s2 into NY where the air mass is less unstable. As such, stronger cells developing this afternoon may acquire rotation with tornado potential. Overnight, the strong shortwave trough will move across southwest Ontario, skirting the Lake Ontario area and into northern NY. Given the strength of the trough, and forecast theta-e advection around 850 mb ahead of the system, additional nocturnal storms producing wind or hail will be possible. ..Jewell.. 06/29/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Jun 29 2024/ ...Lower Great Lakes and Upper Ohio Valley into the Mid-Atlantic... A loosely organized band of convection is ongoing across parts of northern/central OH. As an upper trough over the Great Lakes and eastern Canada continues to move eastward through the period, current expectations are for convection to gradually increase in coverage and intensity this afternoon across eastern OH into western PA. Recent visible satellite imagery shows substantial cloudiness across this area, which should hinder diurnal heating to some extent. Still, even modest heating of the rather moist low-level airmass should support at least weak instability by late this afternoon. Low-level and deep-layer shear appear sufficiently strong for a mix of multicells and supercells. Damaging winds will be a concern with any bowing cluster that can form and spread eastward across parts of the Mid-Atlantic through the afternoon/evening. A couple of tornadoes may also occur with any sustained supercell or embedded QLCS circulations. See Mesoscale Discussion 1472 for more details on the short-term severe threat across OH into northern WV and western PA. There also appears to be some chance for additional convection to develop along the cold front across IL/IN this afternoon, perhaps associated with a remnant MCV over eastern MO. Substantial cloudiness is present across much of this region ahead of the front. But, any thunderstorms that can form may be capable of producing isolated hail and/or strong to damaging winds. Considered including this area in a Slight Risk, but confidence remains low in robust convection persisting with eastward extent into the OH Valley in the wake of earlier thunderstorm activity. ...Ozarks... A Slight Risk for damaging winds has been introduced for southern MO, northeast OK, and vicinity. Outflow from earlier convection, along with the slowly sagging cold front, should continue southward across these areas through late afternoon while also providing a focus for additional convection. Moderate to strong instability is forecast to develop this afternoon in a narrow zone along/ahead of the front. While deep-layer shear should remain fairly modest, most 12Z guidance shows a greater concentration of robust convection developing across southern MO and vicinity late this afternoon and early evening. Loosely organized clusters capable of producing mainly damaging winds should spread generally east-southeastward through the evening. Isolated hail may also occur. ...Southern/Central High Plains... No changes have been made to the Slight Risk across the southern/central High Plains. Scattered thunderstorms are expected to develop during the late afternoon and evening in a weak post-frontal, upslope flow regime. Generally upper 50s to low 60s surface dewpoints and steep mid-level lapse rates will support a narrow corridor of moderate instability by late afternoon. While mid-level flow is expected to remain weak, vertically veering wind profiles with height through mid/upper levels will support sufficient deep shear for transient, slow-moving supercells and loosely organized clusters developing off the higher terrain of southern CO and northern NM. Occasional severe gusts appear possible with this activity as low-level lapse rates become steepened through diurnal heating. Some hail may also occur with the strongest cores. ...Michigan... Despite veered low-level winds ahead of the cold front and weak mid-level lapse rates, boundary-layer heating should yield a plume of weak instability, with MLCAPE around 500-1000 J/kg by this afternoon. Strong speed shear will support hodograph elongation. This may yield a supercell or two capable of isolated severe hail and locally strong wind gusts in the eastern U.P. into Lower MI. But, overall coverage of strong/severe thunderstorms is expected to remain rather limited across this area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sat Jun 29 2024 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY/MID-ATLANTIC...OZARKS VICINITY...AND THE SOUTHERN/CENTRAL HIGH PLAINS...... ...SUMMARY... Damaging thunderstorm gusts and a few tornadoes appear possible today over parts of the Lower Great Lakes to upper Ohio Valley and Mid-Atlantic. Severe gusts may also be focused this afternoon and evening over the Ozarks vicinity, and the Raton Mesa and adjacent south-central High Plains. ...20Z Update... Extended the Slight Risk westward toward Indiana due to ongoing severe cluster of storms, and an extremely moist air mass ahead of it. GPS PWAT values exceed 2.25" over much of the area, and low-level lapse rates continue to steepen just south, which should support corridors of damaging wind. Farther east, tornado watch 482 remains in effect from eastern OH into PA and toward the NY border. Scattered storms persist, and southwesterly low-level winds will aid theta-e advection into the region. In addition, 0-1 km SRH remains favorable at over 150 m2/s2 from OH to central PA, with stronger values up to 300 m2/s2 into NY where the air mass is less unstable. As such, stronger cells developing this afternoon may acquire rotation with tornado potential. Overnight, the strong shortwave trough will move across southwest Ontario, skirting the Lake Ontario area and into northern NY. Given the strength of the trough, and forecast theta-e advection around 850 mb ahead of the system, additional nocturnal storms producing wind or hail will be possible. ..Jewell.. 06/29/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Jun 29 2024/ ...Lower Great Lakes and Upper Ohio Valley into the Mid-Atlantic... A loosely organized band of convection is ongoing across parts of northern/central OH. As an upper trough over the Great Lakes and eastern Canada continues to move eastward through the period, current expectations are for convection to gradually increase in coverage and intensity this afternoon across eastern OH into western PA. Recent visible satellite imagery shows substantial cloudiness across this area, which should hinder diurnal heating to some extent. Still, even modest heating of the rather moist low-level airmass should support at least weak instability by late this afternoon. Low-level and deep-layer shear appear sufficiently strong for a mix of multicells and supercells. Damaging winds will be a concern with any bowing cluster that can form and spread eastward across parts of the Mid-Atlantic through the afternoon/evening. A couple of tornadoes may also occur with any sustained supercell or embedded QLCS circulations. See Mesoscale Discussion 1472 for more details on the short-term severe threat across OH into northern WV and western PA. There also appears to be some chance for additional convection to develop along the cold front across IL/IN this afternoon, perhaps associated with a remnant MCV over eastern MO. Substantial cloudiness is present across much of this region ahead of the front. But, any thunderstorms that can form may be capable of producing isolated hail and/or strong to damaging winds. Considered including this area in a Slight Risk, but confidence remains low in robust convection persisting with eastward extent into the OH Valley in the wake of earlier thunderstorm activity. ...Ozarks... A Slight Risk for damaging winds has been introduced for southern MO, northeast OK, and vicinity. Outflow from earlier convection, along with the slowly sagging cold front, should continue southward across these areas through late afternoon while also providing a focus for additional convection. Moderate to strong instability is forecast to develop this afternoon in a narrow zone along/ahead of the front. While deep-layer shear should remain fairly modest, most 12Z guidance shows a greater concentration of robust convection developing across southern MO and vicinity late this afternoon and early evening. Loosely organized clusters capable of producing mainly damaging winds should spread generally east-southeastward through the evening. Isolated hail may also occur. ...Southern/Central High Plains... No changes have been made to the Slight Risk across the southern/central High Plains. Scattered thunderstorms are expected to develop during the late afternoon and evening in a weak post-frontal, upslope flow regime. Generally upper 50s to low 60s surface dewpoints and steep mid-level lapse rates will support a narrow corridor of moderate instability by late afternoon. While mid-level flow is expected to remain weak, vertically veering wind profiles with height through mid/upper levels will support sufficient deep shear for transient, slow-moving supercells and loosely organized clusters developing off the higher terrain of southern CO and northern NM. Occasional severe gusts appear possible with this activity as low-level lapse rates become steepened through diurnal heating. Some hail may also occur with the strongest cores. ...Michigan... Despite veered low-level winds ahead of the cold front and weak mid-level lapse rates, boundary-layer heating should yield a plume of weak instability, with MLCAPE around 500-1000 J/kg by this afternoon. Strong speed shear will support hodograph elongation. This may yield a supercell or two capable of isolated severe hail and locally strong wind gusts in the eastern U.P. into Lower MI. But, overall coverage of strong/severe thunderstorms is expected to remain rather limited across this area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sat Jun 29 2024 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY/MID-ATLANTIC...OZARKS VICINITY...AND THE SOUTHERN/CENTRAL HIGH PLAINS...... ...SUMMARY... Damaging thunderstorm gusts and a few tornadoes appear possible today over parts of the Lower Great Lakes to upper Ohio Valley and Mid-Atlantic. Severe gusts may also be focused this afternoon and evening over the Ozarks vicinity, and the Raton Mesa and adjacent south-central High Plains. ...20Z Update... Extended the Slight Risk westward toward Indiana due to ongoing severe cluster of storms, and an extremely moist air mass ahead of it. GPS PWAT values exceed 2.25" over much of the area, and low-level lapse rates continue to steepen just south, which should support corridors of damaging wind. Farther east, tornado watch 482 remains in effect from eastern OH into PA and toward the NY border. Scattered storms persist, and southwesterly low-level winds will aid theta-e advection into the region. In addition, 0-1 km SRH remains favorable at over 150 m2/s2 from OH to central PA, with stronger values up to 300 m2/s2 into NY where the air mass is less unstable. As such, stronger cells developing this afternoon may acquire rotation with tornado potential. Overnight, the strong shortwave trough will move across southwest Ontario, skirting the Lake Ontario area and into northern NY. Given the strength of the trough, and forecast theta-e advection around 850 mb ahead of the system, additional nocturnal storms producing wind or hail will be possible. ..Jewell.. 06/29/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Jun 29 2024/ ...Lower Great Lakes and Upper Ohio Valley into the Mid-Atlantic... A loosely organized band of convection is ongoing across parts of northern/central OH. As an upper trough over the Great Lakes and eastern Canada continues to move eastward through the period, current expectations are for convection to gradually increase in coverage and intensity this afternoon across eastern OH into western PA. Recent visible satellite imagery shows substantial cloudiness across this area, which should hinder diurnal heating to some extent. Still, even modest heating of the rather moist low-level airmass should support at least weak instability by late this afternoon. Low-level and deep-layer shear appear sufficiently strong for a mix of multicells and supercells. Damaging winds will be a concern with any bowing cluster that can form and spread eastward across parts of the Mid-Atlantic through the afternoon/evening. A couple of tornadoes may also occur with any sustained supercell or embedded QLCS circulations. See Mesoscale Discussion 1472 for more details on the short-term severe threat across OH into northern WV and western PA. There also appears to be some chance for additional convection to develop along the cold front across IL/IN this afternoon, perhaps associated with a remnant MCV over eastern MO. Substantial cloudiness is present across much of this region ahead of the front. But, any thunderstorms that can form may be capable of producing isolated hail and/or strong to damaging winds. Considered including this area in a Slight Risk, but confidence remains low in robust convection persisting with eastward extent into the OH Valley in the wake of earlier thunderstorm activity. ...Ozarks... A Slight Risk for damaging winds has been introduced for southern MO, northeast OK, and vicinity. Outflow from earlier convection, along with the slowly sagging cold front, should continue southward across these areas through late afternoon while also providing a focus for additional convection. Moderate to strong instability is forecast to develop this afternoon in a narrow zone along/ahead of the front. While deep-layer shear should remain fairly modest, most 12Z guidance shows a greater concentration of robust convection developing across southern MO and vicinity late this afternoon and early evening. Loosely organized clusters capable of producing mainly damaging winds should spread generally east-southeastward through the evening. Isolated hail may also occur. ...Southern/Central High Plains... No changes have been made to the Slight Risk across the southern/central High Plains. Scattered thunderstorms are expected to develop during the late afternoon and evening in a weak post-frontal, upslope flow regime. Generally upper 50s to low 60s surface dewpoints and steep mid-level lapse rates will support a narrow corridor of moderate instability by late afternoon. While mid-level flow is expected to remain weak, vertically veering wind profiles with height through mid/upper levels will support sufficient deep shear for transient, slow-moving supercells and loosely organized clusters developing off the higher terrain of southern CO and northern NM. Occasional severe gusts appear possible with this activity as low-level lapse rates become steepened through diurnal heating. Some hail may also occur with the strongest cores. ...Michigan... Despite veered low-level winds ahead of the cold front and weak mid-level lapse rates, boundary-layer heating should yield a plume of weak instability, with MLCAPE around 500-1000 J/kg by this afternoon. Strong speed shear will support hodograph elongation. This may yield a supercell or two capable of isolated severe hail and locally strong wind gusts in the eastern U.P. into Lower MI. But, overall coverage of strong/severe thunderstorms is expected to remain rather limited across this area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sat Jun 29 2024 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY/MID-ATLANTIC...OZARKS VICINITY...AND THE SOUTHERN/CENTRAL HIGH PLAINS...... ...SUMMARY... Damaging thunderstorm gusts and a few tornadoes appear possible today over parts of the Lower Great Lakes to upper Ohio Valley and Mid-Atlantic. Severe gusts may also be focused this afternoon and evening over the Ozarks vicinity, and the Raton Mesa and adjacent south-central High Plains. ...20Z Update... Extended the Slight Risk westward toward Indiana due to ongoing severe cluster of storms, and an extremely moist air mass ahead of it. GPS PWAT values exceed 2.25" over much of the area, and low-level lapse rates continue to steepen just south, which should support corridors of damaging wind. Farther east, tornado watch 482 remains in effect from eastern OH into PA and toward the NY border. Scattered storms persist, and southwesterly low-level winds will aid theta-e advection into the region. In addition, 0-1 km SRH remains favorable at over 150 m2/s2 from OH to central PA, with stronger values up to 300 m2/s2 into NY where the air mass is less unstable. As such, stronger cells developing this afternoon may acquire rotation with tornado potential. Overnight, the strong shortwave trough will move across southwest Ontario, skirting the Lake Ontario area and into northern NY. Given the strength of the trough, and forecast theta-e advection around 850 mb ahead of the system, additional nocturnal storms producing wind or hail will be possible. ..Jewell.. 06/29/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Jun 29 2024/ ...Lower Great Lakes and Upper Ohio Valley into the Mid-Atlantic... A loosely organized band of convection is ongoing across parts of northern/central OH. As an upper trough over the Great Lakes and eastern Canada continues to move eastward through the period, current expectations are for convection to gradually increase in coverage and intensity this afternoon across eastern OH into western PA. Recent visible satellite imagery shows substantial cloudiness across this area, which should hinder diurnal heating to some extent. Still, even modest heating of the rather moist low-level airmass should support at least weak instability by late this afternoon. Low-level and deep-layer shear appear sufficiently strong for a mix of multicells and supercells. Damaging winds will be a concern with any bowing cluster that can form and spread eastward across parts of the Mid-Atlantic through the afternoon/evening. A couple of tornadoes may also occur with any sustained supercell or embedded QLCS circulations. See Mesoscale Discussion 1472 for more details on the short-term severe threat across OH into northern WV and western PA. There also appears to be some chance for additional convection to develop along the cold front across IL/IN this afternoon, perhaps associated with a remnant MCV over eastern MO. Substantial cloudiness is present across much of this region ahead of the front. But, any thunderstorms that can form may be capable of producing isolated hail and/or strong to damaging winds. Considered including this area in a Slight Risk, but confidence remains low in robust convection persisting with eastward extent into the OH Valley in the wake of earlier thunderstorm activity. ...Ozarks... A Slight Risk for damaging winds has been introduced for southern MO, northeast OK, and vicinity. Outflow from earlier convection, along with the slowly sagging cold front, should continue southward across these areas through late afternoon while also providing a focus for additional convection. Moderate to strong instability is forecast to develop this afternoon in a narrow zone along/ahead of the front. While deep-layer shear should remain fairly modest, most 12Z guidance shows a greater concentration of robust convection developing across southern MO and vicinity late this afternoon and early evening. Loosely organized clusters capable of producing mainly damaging winds should spread generally east-southeastward through the evening. Isolated hail may also occur. ...Southern/Central High Plains... No changes have been made to the Slight Risk across the southern/central High Plains. Scattered thunderstorms are expected to develop during the late afternoon and evening in a weak post-frontal, upslope flow regime. Generally upper 50s to low 60s surface dewpoints and steep mid-level lapse rates will support a narrow corridor of moderate instability by late afternoon. While mid-level flow is expected to remain weak, vertically veering wind profiles with height through mid/upper levels will support sufficient deep shear for transient, slow-moving supercells and loosely organized clusters developing off the higher terrain of southern CO and northern NM. Occasional severe gusts appear possible with this activity as low-level lapse rates become steepened through diurnal heating. Some hail may also occur with the strongest cores. ...Michigan... Despite veered low-level winds ahead of the cold front and weak mid-level lapse rates, boundary-layer heating should yield a plume of weak instability, with MLCAPE around 500-1000 J/kg by this afternoon. Strong speed shear will support hodograph elongation. This may yield a supercell or two capable of isolated severe hail and locally strong wind gusts in the eastern U.P. into Lower MI. But, overall coverage of strong/severe thunderstorms is expected to remain rather limited across this area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sat Jun 29 2024 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY/MID-ATLANTIC...OZARKS VICINITY...AND THE SOUTHERN/CENTRAL HIGH PLAINS...... ...SUMMARY... Damaging thunderstorm gusts and a few tornadoes appear possible today over parts of the Lower Great Lakes to upper Ohio Valley and Mid-Atlantic. Severe gusts may also be focused this afternoon and evening over the Ozarks vicinity, and the Raton Mesa and adjacent south-central High Plains. ...20Z Update... Extended the Slight Risk westward toward Indiana due to ongoing severe cluster of storms, and an extremely moist air mass ahead of it. GPS PWAT values exceed 2.25" over much of the area, and low-level lapse rates continue to steepen just south, which should support corridors of damaging wind. Farther east, tornado watch 482 remains in effect from eastern OH into PA and toward the NY border. Scattered storms persist, and southwesterly low-level winds will aid theta-e advection into the region. In addition, 0-1 km SRH remains favorable at over 150 m2/s2 from OH to central PA, with stronger values up to 300 m2/s2 into NY where the air mass is less unstable. As such, stronger cells developing this afternoon may acquire rotation with tornado potential. Overnight, the strong shortwave trough will move across southwest Ontario, skirting the Lake Ontario area and into northern NY. Given the strength of the trough, and forecast theta-e advection around 850 mb ahead of the system, additional nocturnal storms producing wind or hail will be possible. ..Jewell.. 06/29/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Jun 29 2024/ ...Lower Great Lakes and Upper Ohio Valley into the Mid-Atlantic... A loosely organized band of convection is ongoing across parts of northern/central OH. As an upper trough over the Great Lakes and eastern Canada continues to move eastward through the period, current expectations are for convection to gradually increase in coverage and intensity this afternoon across eastern OH into western PA. Recent visible satellite imagery shows substantial cloudiness across this area, which should hinder diurnal heating to some extent. Still, even modest heating of the rather moist low-level airmass should support at least weak instability by late this afternoon. Low-level and deep-layer shear appear sufficiently strong for a mix of multicells and supercells. Damaging winds will be a concern with any bowing cluster that can form and spread eastward across parts of the Mid-Atlantic through the afternoon/evening. A couple of tornadoes may also occur with any sustained supercell or embedded QLCS circulations. See Mesoscale Discussion 1472 for more details on the short-term severe threat across OH into northern WV and western PA. There also appears to be some chance for additional convection to develop along the cold front across IL/IN this afternoon, perhaps associated with a remnant MCV over eastern MO. Substantial cloudiness is present across much of this region ahead of the front. But, any thunderstorms that can form may be capable of producing isolated hail and/or strong to damaging winds. Considered including this area in a Slight Risk, but confidence remains low in robust convection persisting with eastward extent into the OH Valley in the wake of earlier thunderstorm activity. ...Ozarks... A Slight Risk for damaging winds has been introduced for southern MO, northeast OK, and vicinity. Outflow from earlier convection, along with the slowly sagging cold front, should continue southward across these areas through late afternoon while also providing a focus for additional convection. Moderate to strong instability is forecast to develop this afternoon in a narrow zone along/ahead of the front. While deep-layer shear should remain fairly modest, most 12Z guidance shows a greater concentration of robust convection developing across southern MO and vicinity late this afternoon and early evening. Loosely organized clusters capable of producing mainly damaging winds should spread generally east-southeastward through the evening. Isolated hail may also occur. ...Southern/Central High Plains... No changes have been made to the Slight Risk across the southern/central High Plains. Scattered thunderstorms are expected to develop during the late afternoon and evening in a weak post-frontal, upslope flow regime. Generally upper 50s to low 60s surface dewpoints and steep mid-level lapse rates will support a narrow corridor of moderate instability by late afternoon. While mid-level flow is expected to remain weak, vertically veering wind profiles with height through mid/upper levels will support sufficient deep shear for transient, slow-moving supercells and loosely organized clusters developing off the higher terrain of southern CO and northern NM. Occasional severe gusts appear possible with this activity as low-level lapse rates become steepened through diurnal heating. Some hail may also occur with the strongest cores. ...Michigan... Despite veered low-level winds ahead of the cold front and weak mid-level lapse rates, boundary-layer heating should yield a plume of weak instability, with MLCAPE around 500-1000 J/kg by this afternoon. Strong speed shear will support hodograph elongation. This may yield a supercell or two capable of isolated severe hail and locally strong wind gusts in the eastern U.P. into Lower MI. But, overall coverage of strong/severe thunderstorms is expected to remain rather limited across this area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sat Jun 29 2024 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY/MID-ATLANTIC...OZARKS VICINITY...AND THE SOUTHERN/CENTRAL HIGH PLAINS...... ...SUMMARY... Damaging thunderstorm gusts and a few tornadoes appear possible today over parts of the Lower Great Lakes to upper Ohio Valley and Mid-Atlantic. Severe gusts may also be focused this afternoon and evening over the Ozarks vicinity, and the Raton Mesa and adjacent south-central High Plains. ...20Z Update... Extended the Slight Risk westward toward Indiana due to ongoing severe cluster of storms, and an extremely moist air mass ahead of it. GPS PWAT values exceed 2.25" over much of the area, and low-level lapse rates continue to steepen just south, which should support corridors of damaging wind. Farther east, tornado watch 482 remains in effect from eastern OH into PA and toward the NY border. Scattered storms persist, and southwesterly low-level winds will aid theta-e advection into the region. In addition, 0-1 km SRH remains favorable at over 150 m2/s2 from OH to central PA, with stronger values up to 300 m2/s2 into NY where the air mass is less unstable. As such, stronger cells developing this afternoon may acquire rotation with tornado potential. Overnight, the strong shortwave trough will move across southwest Ontario, skirting the Lake Ontario area and into northern NY. Given the strength of the trough, and forecast theta-e advection around 850 mb ahead of the system, additional nocturnal storms producing wind or hail will be possible. ..Jewell.. 06/29/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Jun 29 2024/ ...Lower Great Lakes and Upper Ohio Valley into the Mid-Atlantic... A loosely organized band of convection is ongoing across parts of northern/central OH. As an upper trough over the Great Lakes and eastern Canada continues to move eastward through the period, current expectations are for convection to gradually increase in coverage and intensity this afternoon across eastern OH into western PA. Recent visible satellite imagery shows substantial cloudiness across this area, which should hinder diurnal heating to some extent. Still, even modest heating of the rather moist low-level airmass should support at least weak instability by late this afternoon. Low-level and deep-layer shear appear sufficiently strong for a mix of multicells and supercells. Damaging winds will be a concern with any bowing cluster that can form and spread eastward across parts of the Mid-Atlantic through the afternoon/evening. A couple of tornadoes may also occur with any sustained supercell or embedded QLCS circulations. See Mesoscale Discussion 1472 for more details on the short-term severe threat across OH into northern WV and western PA. There also appears to be some chance for additional convection to develop along the cold front across IL/IN this afternoon, perhaps associated with a remnant MCV over eastern MO. Substantial cloudiness is present across much of this region ahead of the front. But, any thunderstorms that can form may be capable of producing isolated hail and/or strong to damaging winds. Considered including this area in a Slight Risk, but confidence remains low in robust convection persisting with eastward extent into the OH Valley in the wake of earlier thunderstorm activity. ...Ozarks... A Slight Risk for damaging winds has been introduced for southern MO, northeast OK, and vicinity. Outflow from earlier convection, along with the slowly sagging cold front, should continue southward across these areas through late afternoon while also providing a focus for additional convection. Moderate to strong instability is forecast to develop this afternoon in a narrow zone along/ahead of the front. While deep-layer shear should remain fairly modest, most 12Z guidance shows a greater concentration of robust convection developing across southern MO and vicinity late this afternoon and early evening. Loosely organized clusters capable of producing mainly damaging winds should spread generally east-southeastward through the evening. Isolated hail may also occur. ...Southern/Central High Plains... No changes have been made to the Slight Risk across the southern/central High Plains. Scattered thunderstorms are expected to develop during the late afternoon and evening in a weak post-frontal, upslope flow regime. Generally upper 50s to low 60s surface dewpoints and steep mid-level lapse rates will support a narrow corridor of moderate instability by late afternoon. While mid-level flow is expected to remain weak, vertically veering wind profiles with height through mid/upper levels will support sufficient deep shear for transient, slow-moving supercells and loosely organized clusters developing off the higher terrain of southern CO and northern NM. Occasional severe gusts appear possible with this activity as low-level lapse rates become steepened through diurnal heating. Some hail may also occur with the strongest cores. ...Michigan... Despite veered low-level winds ahead of the cold front and weak mid-level lapse rates, boundary-layer heating should yield a plume of weak instability, with MLCAPE around 500-1000 J/kg by this afternoon. Strong speed shear will support hodograph elongation. This may yield a supercell or two capable of isolated severe hail and locally strong wind gusts in the eastern U.P. into Lower MI. But, overall coverage of strong/severe thunderstorms is expected to remain rather limited across this area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sat Jun 29 2024 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY/MID-ATLANTIC...OZARKS VICINITY...AND THE SOUTHERN/CENTRAL HIGH PLAINS...... ...SUMMARY... Damaging thunderstorm gusts and a few tornadoes appear possible today over parts of the Lower Great Lakes to upper Ohio Valley and Mid-Atlantic. Severe gusts may also be focused this afternoon and evening over the Ozarks vicinity, and the Raton Mesa and adjacent south-central High Plains. ...20Z Update... Extended the Slight Risk westward toward Indiana due to ongoing severe cluster of storms, and an extremely moist air mass ahead of it. GPS PWAT values exceed 2.25" over much of the area, and low-level lapse rates continue to steepen just south, which should support corridors of damaging wind. Farther east, tornado watch 482 remains in effect from eastern OH into PA and toward the NY border. Scattered storms persist, and southwesterly low-level winds will aid theta-e advection into the region. In addition, 0-1 km SRH remains favorable at over 150 m2/s2 from OH to central PA, with stronger values up to 300 m2/s2 into NY where the air mass is less unstable. As such, stronger cells developing this afternoon may acquire rotation with tornado potential. Overnight, the strong shortwave trough will move across southwest Ontario, skirting the Lake Ontario area and into northern NY. Given the strength of the trough, and forecast theta-e advection around 850 mb ahead of the system, additional nocturnal storms producing wind or hail will be possible. ..Jewell.. 06/29/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Jun 29 2024/ ...Lower Great Lakes and Upper Ohio Valley into the Mid-Atlantic... A loosely organized band of convection is ongoing across parts of northern/central OH. As an upper trough over the Great Lakes and eastern Canada continues to move eastward through the period, current expectations are for convection to gradually increase in coverage and intensity this afternoon across eastern OH into western PA. Recent visible satellite imagery shows substantial cloudiness across this area, which should hinder diurnal heating to some extent. Still, even modest heating of the rather moist low-level airmass should support at least weak instability by late this afternoon. Low-level and deep-layer shear appear sufficiently strong for a mix of multicells and supercells. Damaging winds will be a concern with any bowing cluster that can form and spread eastward across parts of the Mid-Atlantic through the afternoon/evening. A couple of tornadoes may also occur with any sustained supercell or embedded QLCS circulations. See Mesoscale Discussion 1472 for more details on the short-term severe threat across OH into northern WV and western PA. There also appears to be some chance for additional convection to develop along the cold front across IL/IN this afternoon, perhaps associated with a remnant MCV over eastern MO. Substantial cloudiness is present across much of this region ahead of the front. But, any thunderstorms that can form may be capable of producing isolated hail and/or strong to damaging winds. Considered including this area in a Slight Risk, but confidence remains low in robust convection persisting with eastward extent into the OH Valley in the wake of earlier thunderstorm activity. ...Ozarks... A Slight Risk for damaging winds has been introduced for southern MO, northeast OK, and vicinity. Outflow from earlier convection, along with the slowly sagging cold front, should continue southward across these areas through late afternoon while also providing a focus for additional convection. Moderate to strong instability is forecast to develop this afternoon in a narrow zone along/ahead of the front. While deep-layer shear should remain fairly modest, most 12Z guidance shows a greater concentration of robust convection developing across southern MO and vicinity late this afternoon and early evening. Loosely organized clusters capable of producing mainly damaging winds should spread generally east-southeastward through the evening. Isolated hail may also occur. ...Southern/Central High Plains... No changes have been made to the Slight Risk across the southern/central High Plains. Scattered thunderstorms are expected to develop during the late afternoon and evening in a weak post-frontal, upslope flow regime. Generally upper 50s to low 60s surface dewpoints and steep mid-level lapse rates will support a narrow corridor of moderate instability by late afternoon. While mid-level flow is expected to remain weak, vertically veering wind profiles with height through mid/upper levels will support sufficient deep shear for transient, slow-moving supercells and loosely organized clusters developing off the higher terrain of southern CO and northern NM. Occasional severe gusts appear possible with this activity as low-level lapse rates become steepened through diurnal heating. Some hail may also occur with the strongest cores. ...Michigan... Despite veered low-level winds ahead of the cold front and weak mid-level lapse rates, boundary-layer heating should yield a plume of weak instability, with MLCAPE around 500-1000 J/kg by this afternoon. Strong speed shear will support hodograph elongation. This may yield a supercell or two capable of isolated severe hail and locally strong wind gusts in the eastern U.P. into Lower MI. But, overall coverage of strong/severe thunderstorms is expected to remain rather limited across this area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sat Jun 29 2024 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY/MID-ATLANTIC...OZARKS VICINITY...AND THE SOUTHERN/CENTRAL HIGH PLAINS...... ...SUMMARY... Damaging thunderstorm gusts and a few tornadoes appear possible today over parts of the Lower Great Lakes to upper Ohio Valley and Mid-Atlantic. Severe gusts may also be focused this afternoon and evening over the Ozarks vicinity, and the Raton Mesa and adjacent south-central High Plains. ...20Z Update... Extended the Slight Risk westward toward Indiana due to ongoing severe cluster of storms, and an extremely moist air mass ahead of it. GPS PWAT values exceed 2.25" over much of the area, and low-level lapse rates continue to steepen just south, which should support corridors of damaging wind. Farther east, tornado watch 482 remains in effect from eastern OH into PA and toward the NY border. Scattered storms persist, and southwesterly low-level winds will aid theta-e advection into the region. In addition, 0-1 km SRH remains favorable at over 150 m2/s2 from OH to central PA, with stronger values up to 300 m2/s2 into NY where the air mass is less unstable. As such, stronger cells developing this afternoon may acquire rotation with tornado potential. Overnight, the strong shortwave trough will move across southwest Ontario, skirting the Lake Ontario area and into northern NY. Given the strength of the trough, and forecast theta-e advection around 850 mb ahead of the system, additional nocturnal storms producing wind or hail will be possible. ..Jewell.. 06/29/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Jun 29 2024/ ...Lower Great Lakes and Upper Ohio Valley into the Mid-Atlantic... A loosely organized band of convection is ongoing across parts of northern/central OH. As an upper trough over the Great Lakes and eastern Canada continues to move eastward through the period, current expectations are for convection to gradually increase in coverage and intensity this afternoon across eastern OH into western PA. Recent visible satellite imagery shows substantial cloudiness across this area, which should hinder diurnal heating to some extent. Still, even modest heating of the rather moist low-level airmass should support at least weak instability by late this afternoon. Low-level and deep-layer shear appear sufficiently strong for a mix of multicells and supercells. Damaging winds will be a concern with any bowing cluster that can form and spread eastward across parts of the Mid-Atlantic through the afternoon/evening. A couple of tornadoes may also occur with any sustained supercell or embedded QLCS circulations. See Mesoscale Discussion 1472 for more details on the short-term severe threat across OH into northern WV and western PA. There also appears to be some chance for additional convection to develop along the cold front across IL/IN this afternoon, perhaps associated with a remnant MCV over eastern MO. Substantial cloudiness is present across much of this region ahead of the front. But, any thunderstorms that can form may be capable of producing isolated hail and/or strong to damaging winds. Considered including this area in a Slight Risk, but confidence remains low in robust convection persisting with eastward extent into the OH Valley in the wake of earlier thunderstorm activity. ...Ozarks... A Slight Risk for damaging winds has been introduced for southern MO, northeast OK, and vicinity. Outflow from earlier convection, along with the slowly sagging cold front, should continue southward across these areas through late afternoon while also providing a focus for additional convection. Moderate to strong instability is forecast to develop this afternoon in a narrow zone along/ahead of the front. While deep-layer shear should remain fairly modest, most 12Z guidance shows a greater concentration of robust convection developing across southern MO and vicinity late this afternoon and early evening. Loosely organized clusters capable of producing mainly damaging winds should spread generally east-southeastward through the evening. Isolated hail may also occur. ...Southern/Central High Plains... No changes have been made to the Slight Risk across the southern/central High Plains. Scattered thunderstorms are expected to develop during the late afternoon and evening in a weak post-frontal, upslope flow regime. Generally upper 50s to low 60s surface dewpoints and steep mid-level lapse rates will support a narrow corridor of moderate instability by late afternoon. While mid-level flow is expected to remain weak, vertically veering wind profiles with height through mid/upper levels will support sufficient deep shear for transient, slow-moving supercells and loosely organized clusters developing off the higher terrain of southern CO and northern NM. Occasional severe gusts appear possible with this activity as low-level lapse rates become steepened through diurnal heating. Some hail may also occur with the strongest cores. ...Michigan... Despite veered low-level winds ahead of the cold front and weak mid-level lapse rates, boundary-layer heating should yield a plume of weak instability, with MLCAPE around 500-1000 J/kg by this afternoon. Strong speed shear will support hodograph elongation. This may yield a supercell or two capable of isolated severe hail and locally strong wind gusts in the eastern U.P. into Lower MI. But, overall coverage of strong/severe thunderstorms is expected to remain rather limited across this area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sat Jun 29 2024 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY/MID-ATLANTIC...OZARKS VICINITY...AND THE SOUTHERN/CENTRAL HIGH PLAINS...... ...SUMMARY... Damaging thunderstorm gusts and a few tornadoes appear possible today over parts of the Lower Great Lakes to upper Ohio Valley and Mid-Atlantic. Severe gusts may also be focused this afternoon and evening over the Ozarks vicinity, and the Raton Mesa and adjacent south-central High Plains. ...20Z Update... Extended the Slight Risk westward toward Indiana due to ongoing severe cluster of storms, and an extremely moist air mass ahead of it. GPS PWAT values exceed 2.25" over much of the area, and low-level lapse rates continue to steepen just south, which should support corridors of damaging wind. Farther east, tornado watch 482 remains in effect from eastern OH into PA and toward the NY border. Scattered storms persist, and southwesterly low-level winds will aid theta-e advection into the region. In addition, 0-1 km SRH remains favorable at over 150 m2/s2 from OH to central PA, with stronger values up to 300 m2/s2 into NY where the air mass is less unstable. As such, stronger cells developing this afternoon may acquire rotation with tornado potential. Overnight, the strong shortwave trough will move across southwest Ontario, skirting the Lake Ontario area and into northern NY. Given the strength of the trough, and forecast theta-e advection around 850 mb ahead of the system, additional nocturnal storms producing wind or hail will be possible. ..Jewell.. 06/29/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Jun 29 2024/ ...Lower Great Lakes and Upper Ohio Valley into the Mid-Atlantic... A loosely organized band of convection is ongoing across parts of northern/central OH. As an upper trough over the Great Lakes and eastern Canada continues to move eastward through the period, current expectations are for convection to gradually increase in coverage and intensity this afternoon across eastern OH into western PA. Recent visible satellite imagery shows substantial cloudiness across this area, which should hinder diurnal heating to some extent. Still, even modest heating of the rather moist low-level airmass should support at least weak instability by late this afternoon. Low-level and deep-layer shear appear sufficiently strong for a mix of multicells and supercells. Damaging winds will be a concern with any bowing cluster that can form and spread eastward across parts of the Mid-Atlantic through the afternoon/evening. A couple of tornadoes may also occur with any sustained supercell or embedded QLCS circulations. See Mesoscale Discussion 1472 for more details on the short-term severe threat across OH into northern WV and western PA. There also appears to be some chance for additional convection to develop along the cold front across IL/IN this afternoon, perhaps associated with a remnant MCV over eastern MO. Substantial cloudiness is present across much of this region ahead of the front. But, any thunderstorms that can form may be capable of producing isolated hail and/or strong to damaging winds. Considered including this area in a Slight Risk, but confidence remains low in robust convection persisting with eastward extent into the OH Valley in the wake of earlier thunderstorm activity. ...Ozarks... A Slight Risk for damaging winds has been introduced for southern MO, northeast OK, and vicinity. Outflow from earlier convection, along with the slowly sagging cold front, should continue southward across these areas through late afternoon while also providing a focus for additional convection. Moderate to strong instability is forecast to develop this afternoon in a narrow zone along/ahead of the front. While deep-layer shear should remain fairly modest, most 12Z guidance shows a greater concentration of robust convection developing across southern MO and vicinity late this afternoon and early evening. Loosely organized clusters capable of producing mainly damaging winds should spread generally east-southeastward through the evening. Isolated hail may also occur. ...Southern/Central High Plains... No changes have been made to the Slight Risk across the southern/central High Plains. Scattered thunderstorms are expected to develop during the late afternoon and evening in a weak post-frontal, upslope flow regime. Generally upper 50s to low 60s surface dewpoints and steep mid-level lapse rates will support a narrow corridor of moderate instability by late afternoon. While mid-level flow is expected to remain weak, vertically veering wind profiles with height through mid/upper levels will support sufficient deep shear for transient, slow-moving supercells and loosely organized clusters developing off the higher terrain of southern CO and northern NM. Occasional severe gusts appear possible with this activity as low-level lapse rates become steepened through diurnal heating. Some hail may also occur with the strongest cores. ...Michigan... Despite veered low-level winds ahead of the cold front and weak mid-level lapse rates, boundary-layer heating should yield a plume of weak instability, with MLCAPE around 500-1000 J/kg by this afternoon. Strong speed shear will support hodograph elongation. This may yield a supercell or two capable of isolated severe hail and locally strong wind gusts in the eastern U.P. into Lower MI. But, overall coverage of strong/severe thunderstorms is expected to remain rather limited across this area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sat Jun 29 2024 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY/MID-ATLANTIC...OZARKS VICINITY...AND THE SOUTHERN/CENTRAL HIGH PLAINS...... ...SUMMARY... Damaging thunderstorm gusts and a few tornadoes appear possible today over parts of the Lower Great Lakes to upper Ohio Valley and Mid-Atlantic. Severe gusts may also be focused this afternoon and evening over the Ozarks vicinity, and the Raton Mesa and adjacent south-central High Plains. ...20Z Update... Extended the Slight Risk westward toward Indiana due to ongoing severe cluster of storms, and an extremely moist air mass ahead of it. GPS PWAT values exceed 2.25" over much of the area, and low-level lapse rates continue to steepen just south, which should support corridors of damaging wind. Farther east, tornado watch 482 remains in effect from eastern OH into PA and toward the NY border. Scattered storms persist, and southwesterly low-level winds will aid theta-e advection into the region. In addition, 0-1 km SRH remains favorable at over 150 m2/s2 from OH to central PA, with stronger values up to 300 m2/s2 into NY where the air mass is less unstable. As such, stronger cells developing this afternoon may acquire rotation with tornado potential. Overnight, the strong shortwave trough will move across southwest Ontario, skirting the Lake Ontario area and into northern NY. Given the strength of the trough, and forecast theta-e advection around 850 mb ahead of the system, additional nocturnal storms producing wind or hail will be possible. ..Jewell.. 06/29/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Jun 29 2024/ ...Lower Great Lakes and Upper Ohio Valley into the Mid-Atlantic... A loosely organized band of convection is ongoing across parts of northern/central OH. As an upper trough over the Great Lakes and eastern Canada continues to move eastward through the period, current expectations are for convection to gradually increase in coverage and intensity this afternoon across eastern OH into western PA. Recent visible satellite imagery shows substantial cloudiness across this area, which should hinder diurnal heating to some extent. Still, even modest heating of the rather moist low-level airmass should support at least weak instability by late this afternoon. Low-level and deep-layer shear appear sufficiently strong for a mix of multicells and supercells. Damaging winds will be a concern with any bowing cluster that can form and spread eastward across parts of the Mid-Atlantic through the afternoon/evening. A couple of tornadoes may also occur with any sustained supercell or embedded QLCS circulations. See Mesoscale Discussion 1472 for more details on the short-term severe threat across OH into northern WV and western PA. There also appears to be some chance for additional convection to develop along the cold front across IL/IN this afternoon, perhaps associated with a remnant MCV over eastern MO. Substantial cloudiness is present across much of this region ahead of the front. But, any thunderstorms that can form may be capable of producing isolated hail and/or strong to damaging winds. Considered including this area in a Slight Risk, but confidence remains low in robust convection persisting with eastward extent into the OH Valley in the wake of earlier thunderstorm activity. ...Ozarks... A Slight Risk for damaging winds has been introduced for southern MO, northeast OK, and vicinity. Outflow from earlier convection, along with the slowly sagging cold front, should continue southward across these areas through late afternoon while also providing a focus for additional convection. Moderate to strong instability is forecast to develop this afternoon in a narrow zone along/ahead of the front. While deep-layer shear should remain fairly modest, most 12Z guidance shows a greater concentration of robust convection developing across southern MO and vicinity late this afternoon and early evening. Loosely organized clusters capable of producing mainly damaging winds should spread generally east-southeastward through the evening. Isolated hail may also occur. ...Southern/Central High Plains... No changes have been made to the Slight Risk across the southern/central High Plains. Scattered thunderstorms are expected to develop during the late afternoon and evening in a weak post-frontal, upslope flow regime. Generally upper 50s to low 60s surface dewpoints and steep mid-level lapse rates will support a narrow corridor of moderate instability by late afternoon. While mid-level flow is expected to remain weak, vertically veering wind profiles with height through mid/upper levels will support sufficient deep shear for transient, slow-moving supercells and loosely organized clusters developing off the higher terrain of southern CO and northern NM. Occasional severe gusts appear possible with this activity as low-level lapse rates become steepened through diurnal heating. Some hail may also occur with the strongest cores. ...Michigan... Despite veered low-level winds ahead of the cold front and weak mid-level lapse rates, boundary-layer heating should yield a plume of weak instability, with MLCAPE around 500-1000 J/kg by this afternoon. Strong speed shear will support hodograph elongation. This may yield a supercell or two capable of isolated severe hail and locally strong wind gusts in the eastern U.P. into Lower MI. But, overall coverage of strong/severe thunderstorms is expected to remain rather limited across this area. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0256 PM CDT Sat Jun 29 2024 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE OHIO VALLEY/MID-ATLANTIC...OZARKS VICINITY...AND THE SOUTHERN/CENTRAL HIGH PLAINS...... ...SUMMARY... Damaging thunderstorm gusts and a few tornadoes appear possible today over parts of the Lower Great Lakes to upper Ohio Valley and Mid-Atlantic. Severe gusts may also be focused this afternoon and evening over the Ozarks vicinity, and the Raton Mesa and adjacent south-central High Plains. ...20Z Update... Extended the Slight Risk westward toward Indiana due to ongoing severe cluster of storms, and an extremely moist air mass ahead of it. GPS PWAT values exceed 2.25" over much of the area, and low-level lapse rates continue to steepen just south, which should support corridors of damaging wind. Farther east, tornado watch 482 remains in effect from eastern OH into PA and toward the NY border. Scattered storms persist, and southwesterly low-level winds will aid theta-e advection into the region. In addition, 0-1 km SRH remains favorable at over 150 m2/s2 from OH to central PA, with stronger values up to 300 m2/s2 into NY where the air mass is less unstable. As such, stronger cells developing this afternoon may acquire rotation with tornado potential. Overnight, the strong shortwave trough will move across southwest Ontario, skirting the Lake Ontario area and into northern NY. Given the strength of the trough, and forecast theta-e advection around 850 mb ahead of the system, additional nocturnal storms producing wind or hail will be possible. ..Jewell.. 06/29/2024 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sat Jun 29 2024/ ...Lower Great Lakes and Upper Ohio Valley into the Mid-Atlantic... A loosely organized band of convection is ongoing across parts of northern/central OH. As an upper trough over the Great Lakes and eastern Canada continues to move eastward through the period, current expectations are for convection to gradually increase in coverage and intensity this afternoon across eastern OH into western PA. Recent visible satellite imagery shows substantial cloudiness across this area, which should hinder diurnal heating to some extent. Still, even modest heating of the rather moist low-level airmass should support at least weak instability by late this afternoon. Low-level and deep-layer shear appear sufficiently strong for a mix of multicells and supercells. Damaging winds will be a concern with any bowing cluster that can form and spread eastward across parts of the Mid-Atlantic through the afternoon/evening. A couple of tornadoes may also occur with any sustained supercell or embedded QLCS circulations. See Mesoscale Discussion 1472 for more details on the short-term severe threat across OH into northern WV and western PA. There also appears to be some chance for additional convection to develop along the cold front across IL/IN this afternoon, perhaps associated with a remnant MCV over eastern MO. Substantial cloudiness is present across much of this region ahead of the front. But, any thunderstorms that can form may be capable of producing isolated hail and/or strong to damaging winds. Considered including this area in a Slight Risk, but confidence remains low in robust convection persisting with eastward extent into the OH Valley in the wake of earlier thunderstorm activity. ...Ozarks... A Slight Risk for damaging winds has been introduced for southern MO, northeast OK, and vicinity. Outflow from earlier convection, along with the slowly sagging cold front, should continue southward across these areas through late afternoon while also providing a focus for additional convection. Moderate to strong instability is forecast to develop this afternoon in a narrow zone along/ahead of the front. While deep-layer shear should remain fairly modest, most 12Z guidance shows a greater concentration of robust convection developing across southern MO and vicinity late this afternoon and early evening. Loosely organized clusters capable of producing mainly damaging winds should spread generally east-southeastward through the evening. Isolated hail may also occur. ...Southern/Central High Plains... No changes have been made to the Slight Risk across the southern/central High Plains. Scattered thunderstorms are expected to develop during the late afternoon and evening in a weak post-frontal, upslope flow regime. Generally upper 50s to low 60s surface dewpoints and steep mid-level lapse rates will support a narrow corridor of moderate instability by late afternoon. While mid-level flow is expected to remain weak, vertically veering wind profiles with height through mid/upper levels will support sufficient deep shear for transient, slow-moving supercells and loosely organized clusters developing off the higher terrain of southern CO and northern NM. Occasional severe gusts appear possible with this activity as low-level lapse rates become steepened through diurnal heating. Some hail may also occur with the strongest cores. ...Michigan... Despite veered low-level winds ahead of the cold front and weak mid-level lapse rates, boundary-layer heating should yield a plume of weak instability, with MLCAPE around 500-1000 J/kg by this afternoon. Strong speed shear will support hodograph elongation. This may yield a supercell or two capable of isolated severe hail and locally strong wind gusts in the eastern U.P. into Lower MI. But, overall coverage of strong/severe thunderstorms is expected to remain rather limited across this area. Read more