Severe Storms

WW 582 SEVERE TSTM CO KS NE 142100Z - 150300Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 582 NWS Storm Prediction Center Norman OK 300 PM MDT Wed Aug 14 2019 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Eastern Colorado Far northwest Kansas Southwest Nebraska Panhandle * Effective this Wednesday afternoon and evening from 300 PM until 900 PM MDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible Isolated damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...A supercell or two may become sustained along a weak boundary near the Wyoming-Colorado-Nebraska border, moving southeast across eastern Colorado into northwest Kansas. The severe thunderstorm watch area is approximately along and 70 statute miles east and west of a line from 60 miles north northwest of Akron CO to 45 miles southwest of Burlington CO. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU2). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 550. Mean storm motion vector 32030. ...Grams Read more

WW 0582 Status Updates
STATUS FOR WATCH 0582 HAS NOT BEEN ISSUED YET Read more

MD 1737 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF NORTHEAST IN INTO NORTHWEST OH
Mesoscale Discussion 1737 NWS Storm Prediction Center Norman OK 0310 PM CDT Wed Aug 14 2019 Areas affected...portions of northeast IN into northwest OH Concerning...Severe potential...Watch unlikely Valid 142010Z - 142145Z Probability of Watch Issuance...5 percent SUMMARY...A couple of strong storms could produce marginal hail and gusty winds through the remainder of the afternoon. DISCUSSION...Isolated thunderstorms have increased in intensity this afternoon from Marshall to Allen counties in IN and Van Wert County in OH. The most intense cell currently is near Fort Wayne, where a cell has interacted with an outflow boundary from a previous decaying cell. This cell has shown some weak rotation, which has probably been enhanced by the interaction with the aforementioned boundary. Some strong gusts and marginal hail are possible with strongest cells this afternoon given around 30 kt effective shear and a weak mid/upper level impulse migrating through westerly deep layer flow. Midlevel lapse rates will remain poor and limit severe hail potential. Steep low level lapse rates and a deeply-mixed sub-cloud layer will favor some stronger downdrafts and gusty winds. Overall, the threat should remain limited in intensity and coverage and a watch is not expected. ..Leitman/Grams.. 08/14/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CLE...ILN...IWX... LAT...LON 41638654 41658622 41338515 40908383 40548322 40338326 40108359 40188419 40658542 41188634 41468661 41638654 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Wed Aug 14 2019 Valid 151200Z - 161200Z The elevated delineation was expanded to further cover portions of the Snake River Plain and Great Divide Basin, where the latest guidance suggests elevated to potentially locally critical conditions may occur. In addition, a couple of dry strikes may occur along the periphery of overall wetter, very isolated storms across northern Idaho into western and southwestern Montana during the late afternoon hours. However, the very sparse storm coverage and overall lack of receptiveness of fuels precludes an isolated thunderstorm delineation. Otherwise, the forecast remains on track (see below for details). ..Squitieri.. 08/14/2019 .PREV DISCUSSION... /ISSUED 1251 AM CDT Wed Aug 14 2019/ ...Synopsis... Mid-level flow will strengthen across portions of the Pacific Northwest and northern Rockies as a couple of shortwaves migrate through the area. Farther south, weak ridging will remain in place across the Southwest. In the East, broadly cyclonic flow aloft will remain in place. ...Eastern Idaho into southwestern Wyoming... Surface flow in this region will be slightly stronger compared to prior days owing to 1) stronger mid-level flow (40-50 kts) and 2) vertical mixing processes. This stronger (15-25 mph) surface flow will occur within areas of dry fuels, with RH values flirting with critical thresholds (around 15% or so) for a few hours in the afternoon/early evening. These conditions are consistent with elevated fire weather, though locally critical conditions cannot be ruled out especially in terrain-favored areas that typically experience locally stronger wind speeds. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Wed Aug 14 2019 Valid 151200Z - 161200Z The elevated delineation was expanded to further cover portions of the Snake River Plain and Great Divide Basin, where the latest guidance suggests elevated to potentially locally critical conditions may occur. In addition, a couple of dry strikes may occur along the periphery of overall wetter, very isolated storms across northern Idaho into western and southwestern Montana during the late afternoon hours. However, the very sparse storm coverage and overall lack of receptiveness of fuels precludes an isolated thunderstorm delineation. Otherwise, the forecast remains on track (see below for details). ..Squitieri.. 08/14/2019 .PREV DISCUSSION... /ISSUED 1251 AM CDT Wed Aug 14 2019/ ...Synopsis... Mid-level flow will strengthen across portions of the Pacific Northwest and northern Rockies as a couple of shortwaves migrate through the area. Farther south, weak ridging will remain in place across the Southwest. In the East, broadly cyclonic flow aloft will remain in place. ...Eastern Idaho into southwestern Wyoming... Surface flow in this region will be slightly stronger compared to prior days owing to 1) stronger mid-level flow (40-50 kts) and 2) vertical mixing processes. This stronger (15-25 mph) surface flow will occur within areas of dry fuels, with RH values flirting with critical thresholds (around 15% or so) for a few hours in the afternoon/early evening. These conditions are consistent with elevated fire weather, though locally critical conditions cannot be ruled out especially in terrain-favored areas that typically experience locally stronger wind speeds. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Wed Aug 14 2019 Valid 151200Z - 161200Z The elevated delineation was expanded to further cover portions of the Snake River Plain and Great Divide Basin, where the latest guidance suggests elevated to potentially locally critical conditions may occur. In addition, a couple of dry strikes may occur along the periphery of overall wetter, very isolated storms across northern Idaho into western and southwestern Montana during the late afternoon hours. However, the very sparse storm coverage and overall lack of receptiveness of fuels precludes an isolated thunderstorm delineation. Otherwise, the forecast remains on track (see below for details). ..Squitieri.. 08/14/2019 .PREV DISCUSSION... /ISSUED 1251 AM CDT Wed Aug 14 2019/ ...Synopsis... Mid-level flow will strengthen across portions of the Pacific Northwest and northern Rockies as a couple of shortwaves migrate through the area. Farther south, weak ridging will remain in place across the Southwest. In the East, broadly cyclonic flow aloft will remain in place. ...Eastern Idaho into southwestern Wyoming... Surface flow in this region will be slightly stronger compared to prior days owing to 1) stronger mid-level flow (40-50 kts) and 2) vertical mixing processes. This stronger (15-25 mph) surface flow will occur within areas of dry fuels, with RH values flirting with critical thresholds (around 15% or so) for a few hours in the afternoon/early evening. These conditions are consistent with elevated fire weather, though locally critical conditions cannot be ruled out especially in terrain-favored areas that typically experience locally stronger wind speeds. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0257 PM CDT Wed Aug 14 2019 Valid 151200Z - 161200Z The elevated delineation was expanded to further cover portions of the Snake River Plain and Great Divide Basin, where the latest guidance suggests elevated to potentially locally critical conditions may occur. In addition, a couple of dry strikes may occur along the periphery of overall wetter, very isolated storms across northern Idaho into western and southwestern Montana during the late afternoon hours. However, the very sparse storm coverage and overall lack of receptiveness of fuels precludes an isolated thunderstorm delineation. Otherwise, the forecast remains on track (see below for details). ..Squitieri.. 08/14/2019 .PREV DISCUSSION... /ISSUED 1251 AM CDT Wed Aug 14 2019/ ...Synopsis... Mid-level flow will strengthen across portions of the Pacific Northwest and northern Rockies as a couple of shortwaves migrate through the area. Farther south, weak ridging will remain in place across the Southwest. In the East, broadly cyclonic flow aloft will remain in place. ...Eastern Idaho into southwestern Wyoming... Surface flow in this region will be slightly stronger compared to prior days owing to 1) stronger mid-level flow (40-50 kts) and 2) vertical mixing processes. This stronger (15-25 mph) surface flow will occur within areas of dry fuels, with RH values flirting with critical thresholds (around 15% or so) for a few hours in the afternoon/early evening. These conditions are consistent with elevated fire weather, though locally critical conditions cannot be ruled out especially in terrain-favored areas that typically experience locally stronger wind speeds. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1736 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF SOUTHEASTERN WY...WESTERN NE...AND EASTERN CO
Mesoscale Discussion 1736 NWS Storm Prediction Center Norman OK 0254 PM CDT Wed Aug 14 2019 Areas affected...Portions of southeastern WY...western NE...and eastern CO Concerning...Severe potential...Watch possible Valid 141954Z - 142200Z Probability of Watch Issuance...60 percent SUMMARY...A gradual increase in an isolated severe risk should occur this afternoon. Large hail, damaging winds, and perhaps a couple tornadoes will all be possible. Watch issuance may be needed by 22Z (4 PM MDT). DISCUSSION...Cumulus is slowly building across the Laramie Mountains of southeastern WY and the Front Range in northern/central CO. Current expectations are for convective inhibition to gradually erode through the remainder of the afternoon across eastern CO, southeastern WY, and parts of western NE. 19Z surface analysis shows a weak surface low over southeastern WY, with a front extending southeastward from this low across the central High Plains. Surface dewpoints across this region are several degrees lower than yesterday, generally in the mid to upper 50s, but up to the lower 60s along and just north of the surface boundary. Still, steep mid-level lapse rates emanating from the Rockies have overspread this area, which coupled with strong diurnal heating will likely support 1500-2500 J/kg of MLCAPE through peak heating. With modestly enhanced northwesterly flow persisting aloft, large-scale forcing for ascent will remain nebulous across the central High Plains this afternoon. This lends some uncertainty regarding overall storm coverage. Isolated storms should eventually form over the higher terrain and slowly move east-southeastward. Additional convective development may occur with weak low-level convergence along the surface boundary extending into parts of western NE. Rather weak low-level flow is expected to persist through the early evening, but northwesterly flow does increase above 3 km, which is promoting around 35-45 kt of effective bulk shear. The presence of steep mid-level lapse rates, moderate instability, and enough shear to support supercells suggests isolated large hail should be the primary threat initially. Very large hail, potentially in excess of 2 inches in diameter, could occur with the strongest storms. A couple of tornadoes may also be possible along and immediately to the cool side of the front where low-level flow is backed to southeasterly, locally augmenting effective SRH. Depending on observational trends, a watch may be needed for some part of this area by 22Z. ..Gleason/Grams.. 08/14/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LBF...GLD...PUB...BOU...CYS... LAT...LON 41040470 41460487 42320535 42540521 42660469 42640404 42080273 41170177 40200142 39510138 38960163 38490213 38350319 38420426 38710465 41040470 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Wed Aug 14 2019 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... Scattered severe thunderstorms with very large hail, a couple tornadoes, and damaging winds are possible across parts of the central and northern High Plains from late afternoon into tonight. ...DISCUSSION... A couple changes to the outlook have been made for this issuance. The first change is to add thunder into parts of the Four Corners region where isolated thunderstorms have developed this afternoon. The second is to add thunder across parts of southeast Oklahoma where thunderstorms have developed on the southern edge of the Ouachita Mountains. ..Broyles.. 08/14/2019 .PREV DISCUSSION... /ISSUED 1130 AM CDT Wed Aug 14 2019/ ...Northern/central High Plains... Confidence in storm coverage and initiation corridors are lower today compared to yesterday. Surface dew points are drier this morning with 50s prevalent to low 60s in KS in the wake of yesterday's convective overturning. Nevertheless, persistent mid-level west-northwesterlies will maintain very steep lapse rates atop the residual boundary-layer moisture and should yield a plume of MLCAPE from 1500-2500 J/kg at peak heating from the Black Hills/eastern WY south across far eastern CO/western KS. Forcing for ascent will be rather weak near the higher terrain and southerly low-level flow dominates eastern CO at present. Convective initiation should be delayed until late afternoon and may be sparse in the central High Plains, with storm coverage beyond a cell or two highly questionable within the corridor most favorable for supercells. Still, effective bulk shear of 40-50 kt with relatively straight hodographs will support the risk of a couple supercells capable of producing isolated very large hail. The tornado threat will likely depend on a discrete cell interacting with the somewhat greater low-level shear/hodograph curvature expected near the CO/KS/NE border area along the east edge of the greater buoyancy. Somewhat greater confidence in convective initiation is across southeast MT/northeast WY owing to peripheral influence of a minor shortwave trough approaching from the Canadian Rockies. Isolated to perhaps scattered storms should develop along the northern extent of the buoyancy plume. There is some signal for upscale growth into a small, increasingly elevated MCS downstream across portions of western SD/NE tonight as a 25-35 kt nocturnal low-level jet develops across the Panhandles to southwest NE. Isolated severe wind and hail will remain possible into the early overnight. ...Central Gulf Coast to the Mid-Atlantic... The effective surface boundary, modulated by convective outflow, will continue to sag southward toward the Central Gulf Coast and southeastward toward the South/Mid-Atlantic coasts. The richer moisture (PW greater than 2 inches) and large buoyancy (MLCAPE of 2500-3500 J/kg) should be confined to the eastern Carolinas southwestward into the central Gulf Coast. Vertical shear will be very weak and boundary/storm mergers will largely drive isolated downburst potential. Somewhat stronger deep-layer shear is expected farther north toward Chesapeake Bay, which could compensate some for the weaker buoyancy and poor mid-level lapse rates. ...Northern IN vicinity... A diffuse surface front will provide a focus for thunderstorm development this afternoon, as a minor mid-level impulse approaches from southern WI. Lingering low-level moisture and surface heating will support MLCAPE of 1000-1500 J/kg, while deep-layer vertical shear will be at least marginally favorable for a couple organized/supercell storms. Very weak low-level flow will greatly limit hodograph size/SRH magnitude, but there will be modest vertical vorticity along the surface boundary. A couple of storms with hail/wind near severe criteria and a brief tornado are all possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Wed Aug 14 2019 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... Scattered severe thunderstorms with very large hail, a couple tornadoes, and damaging winds are possible across parts of the central and northern High Plains from late afternoon into tonight. ...DISCUSSION... A couple changes to the outlook have been made for this issuance. The first change is to add thunder into parts of the Four Corners region where isolated thunderstorms have developed this afternoon. The second is to add thunder across parts of southeast Oklahoma where thunderstorms have developed on the southern edge of the Ouachita Mountains. ..Broyles.. 08/14/2019 .PREV DISCUSSION... /ISSUED 1130 AM CDT Wed Aug 14 2019/ ...Northern/central High Plains... Confidence in storm coverage and initiation corridors are lower today compared to yesterday. Surface dew points are drier this morning with 50s prevalent to low 60s in KS in the wake of yesterday's convective overturning. Nevertheless, persistent mid-level west-northwesterlies will maintain very steep lapse rates atop the residual boundary-layer moisture and should yield a plume of MLCAPE from 1500-2500 J/kg at peak heating from the Black Hills/eastern WY south across far eastern CO/western KS. Forcing for ascent will be rather weak near the higher terrain and southerly low-level flow dominates eastern CO at present. Convective initiation should be delayed until late afternoon and may be sparse in the central High Plains, with storm coverage beyond a cell or two highly questionable within the corridor most favorable for supercells. Still, effective bulk shear of 40-50 kt with relatively straight hodographs will support the risk of a couple supercells capable of producing isolated very large hail. The tornado threat will likely depend on a discrete cell interacting with the somewhat greater low-level shear/hodograph curvature expected near the CO/KS/NE border area along the east edge of the greater buoyancy. Somewhat greater confidence in convective initiation is across southeast MT/northeast WY owing to peripheral influence of a minor shortwave trough approaching from the Canadian Rockies. Isolated to perhaps scattered storms should develop along the northern extent of the buoyancy plume. There is some signal for upscale growth into a small, increasingly elevated MCS downstream across portions of western SD/NE tonight as a 25-35 kt nocturnal low-level jet develops across the Panhandles to southwest NE. Isolated severe wind and hail will remain possible into the early overnight. ...Central Gulf Coast to the Mid-Atlantic... The effective surface boundary, modulated by convective outflow, will continue to sag southward toward the Central Gulf Coast and southeastward toward the South/Mid-Atlantic coasts. The richer moisture (PW greater than 2 inches) and large buoyancy (MLCAPE of 2500-3500 J/kg) should be confined to the eastern Carolinas southwestward into the central Gulf Coast. Vertical shear will be very weak and boundary/storm mergers will largely drive isolated downburst potential. Somewhat stronger deep-layer shear is expected farther north toward Chesapeake Bay, which could compensate some for the weaker buoyancy and poor mid-level lapse rates. ...Northern IN vicinity... A diffuse surface front will provide a focus for thunderstorm development this afternoon, as a minor mid-level impulse approaches from southern WI. Lingering low-level moisture and surface heating will support MLCAPE of 1000-1500 J/kg, while deep-layer vertical shear will be at least marginally favorable for a couple organized/supercell storms. Very weak low-level flow will greatly limit hodograph size/SRH magnitude, but there will be modest vertical vorticity along the surface boundary. A couple of storms with hail/wind near severe criteria and a brief tornado are all possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Wed Aug 14 2019 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... Scattered severe thunderstorms with very large hail, a couple tornadoes, and damaging winds are possible across parts of the central and northern High Plains from late afternoon into tonight. ...DISCUSSION... A couple changes to the outlook have been made for this issuance. The first change is to add thunder into parts of the Four Corners region where isolated thunderstorms have developed this afternoon. The second is to add thunder across parts of southeast Oklahoma where thunderstorms have developed on the southern edge of the Ouachita Mountains. ..Broyles.. 08/14/2019 .PREV DISCUSSION... /ISSUED 1130 AM CDT Wed Aug 14 2019/ ...Northern/central High Plains... Confidence in storm coverage and initiation corridors are lower today compared to yesterday. Surface dew points are drier this morning with 50s prevalent to low 60s in KS in the wake of yesterday's convective overturning. Nevertheless, persistent mid-level west-northwesterlies will maintain very steep lapse rates atop the residual boundary-layer moisture and should yield a plume of MLCAPE from 1500-2500 J/kg at peak heating from the Black Hills/eastern WY south across far eastern CO/western KS. Forcing for ascent will be rather weak near the higher terrain and southerly low-level flow dominates eastern CO at present. Convective initiation should be delayed until late afternoon and may be sparse in the central High Plains, with storm coverage beyond a cell or two highly questionable within the corridor most favorable for supercells. Still, effective bulk shear of 40-50 kt with relatively straight hodographs will support the risk of a couple supercells capable of producing isolated very large hail. The tornado threat will likely depend on a discrete cell interacting with the somewhat greater low-level shear/hodograph curvature expected near the CO/KS/NE border area along the east edge of the greater buoyancy. Somewhat greater confidence in convective initiation is across southeast MT/northeast WY owing to peripheral influence of a minor shortwave trough approaching from the Canadian Rockies. Isolated to perhaps scattered storms should develop along the northern extent of the buoyancy plume. There is some signal for upscale growth into a small, increasingly elevated MCS downstream across portions of western SD/NE tonight as a 25-35 kt nocturnal low-level jet develops across the Panhandles to southwest NE. Isolated severe wind and hail will remain possible into the early overnight. ...Central Gulf Coast to the Mid-Atlantic... The effective surface boundary, modulated by convective outflow, will continue to sag southward toward the Central Gulf Coast and southeastward toward the South/Mid-Atlantic coasts. The richer moisture (PW greater than 2 inches) and large buoyancy (MLCAPE of 2500-3500 J/kg) should be confined to the eastern Carolinas southwestward into the central Gulf Coast. Vertical shear will be very weak and boundary/storm mergers will largely drive isolated downburst potential. Somewhat stronger deep-layer shear is expected farther north toward Chesapeake Bay, which could compensate some for the weaker buoyancy and poor mid-level lapse rates. ...Northern IN vicinity... A diffuse surface front will provide a focus for thunderstorm development this afternoon, as a minor mid-level impulse approaches from southern WI. Lingering low-level moisture and surface heating will support MLCAPE of 1000-1500 J/kg, while deep-layer vertical shear will be at least marginally favorable for a couple organized/supercell storms. Very weak low-level flow will greatly limit hodograph size/SRH magnitude, but there will be modest vertical vorticity along the surface boundary. A couple of storms with hail/wind near severe criteria and a brief tornado are all possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0241 PM CDT Wed Aug 14 2019 Valid 142000Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN HIGH PLAINS... ...SUMMARY... Scattered severe thunderstorms with very large hail, a couple tornadoes, and damaging winds are possible across parts of the central and northern High Plains from late afternoon into tonight. ...DISCUSSION... A couple changes to the outlook have been made for this issuance. The first change is to add thunder into parts of the Four Corners region where isolated thunderstorms have developed this afternoon. The second is to add thunder across parts of southeast Oklahoma where thunderstorms have developed on the southern edge of the Ouachita Mountains. ..Broyles.. 08/14/2019 .PREV DISCUSSION... /ISSUED 1130 AM CDT Wed Aug 14 2019/ ...Northern/central High Plains... Confidence in storm coverage and initiation corridors are lower today compared to yesterday. Surface dew points are drier this morning with 50s prevalent to low 60s in KS in the wake of yesterday's convective overturning. Nevertheless, persistent mid-level west-northwesterlies will maintain very steep lapse rates atop the residual boundary-layer moisture and should yield a plume of MLCAPE from 1500-2500 J/kg at peak heating from the Black Hills/eastern WY south across far eastern CO/western KS. Forcing for ascent will be rather weak near the higher terrain and southerly low-level flow dominates eastern CO at present. Convective initiation should be delayed until late afternoon and may be sparse in the central High Plains, with storm coverage beyond a cell or two highly questionable within the corridor most favorable for supercells. Still, effective bulk shear of 40-50 kt with relatively straight hodographs will support the risk of a couple supercells capable of producing isolated very large hail. The tornado threat will likely depend on a discrete cell interacting with the somewhat greater low-level shear/hodograph curvature expected near the CO/KS/NE border area along the east edge of the greater buoyancy. Somewhat greater confidence in convective initiation is across southeast MT/northeast WY owing to peripheral influence of a minor shortwave trough approaching from the Canadian Rockies. Isolated to perhaps scattered storms should develop along the northern extent of the buoyancy plume. There is some signal for upscale growth into a small, increasingly elevated MCS downstream across portions of western SD/NE tonight as a 25-35 kt nocturnal low-level jet develops across the Panhandles to southwest NE. Isolated severe wind and hail will remain possible into the early overnight. ...Central Gulf Coast to the Mid-Atlantic... The effective surface boundary, modulated by convective outflow, will continue to sag southward toward the Central Gulf Coast and southeastward toward the South/Mid-Atlantic coasts. The richer moisture (PW greater than 2 inches) and large buoyancy (MLCAPE of 2500-3500 J/kg) should be confined to the eastern Carolinas southwestward into the central Gulf Coast. Vertical shear will be very weak and boundary/storm mergers will largely drive isolated downburst potential. Somewhat stronger deep-layer shear is expected farther north toward Chesapeake Bay, which could compensate some for the weaker buoyancy and poor mid-level lapse rates. ...Northern IN vicinity... A diffuse surface front will provide a focus for thunderstorm development this afternoon, as a minor mid-level impulse approaches from southern WI. Lingering low-level moisture and surface heating will support MLCAPE of 1000-1500 J/kg, while deep-layer vertical shear will be at least marginally favorable for a couple organized/supercell storms. Very weak low-level flow will greatly limit hodograph size/SRH magnitude, but there will be modest vertical vorticity along the surface boundary. A couple of storms with hail/wind near severe criteria and a brief tornado are all possible. Read more

No watches are valid as of Wed Aug 14 18:40:01 UTC 2019.

MD 1735 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF EASTERN SC...SOUTHERN AL/GA...THE WESTERN FL PANHANDLE
Mesoscale Discussion 1735 NWS Storm Prediction Center Norman OK 0138 PM CDT Wed Aug 14 2019 Areas affected...portions of eastern SC...southern AL/GA...the western FL Panhandle Concerning...Severe potential...Watch unlikely Valid 141838Z - 142045Z Probability of Watch Issuance...5 percent SUMMARY...A few strong wind gusts will be possible through the afternoon from the central Gulf Coast vicinity northeast toward eastern South Carolina. DISCUSSION...Numerous thunderstorms have developed this afternoon along a southward-sagging cold front. Temperatures well into the 90s and dewpoints in the mid to upper 70s have resulted in moderate to strong instability, with 18z mesoanalysis indicating 2000-3000 J/kg MLCAPE. Effective shear is weak across the region and will limit sustained organized features. However, PW values over 2 inches and low level lapse rates around 7.5-8.5 C/km will support sporadic strong downbursts. A couple of locally damaging gusts will especially be possible if any clusters begin to surge/forward propagate through storm mergers and/or along outflow interactions. Overall, the threat will remain transient and a watch is not expected. ..Leitman/Grams.. 08/14/2019 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ILM...CHS...CAE...JAX...FFC...TAE...BMX...MOB... LAT...LON 31978781 32148575 32528407 32718322 33138133 33867958 33717907 33417898 32987937 32418000 31788076 30668147 30538380 30328574 30318662 30448743 30758780 31118810 31438829 31798825 31978781 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Wed Aug 14 2019 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe storms are expected across parts of the central and northern Plains on Thursday. Isolated severe storms are possible from Ohio into west-central Pennsylvania and across parts of the eastern Carolinas. ...Central and Northern Plains... West to northwest mid-level flow will be in place across the central U.S. on Thursday as a low-amplitude shortwave trough moves east-southeastward into the northern Plains. At the surface, a low will deepen across southwest Kansas as a cold front moves southeastward across eastern Colorado, western Nebraska and central South Dakota. Elevated convection should be ongoing in parts of the central Plains during the morning associated with the exit region of the low-level jet. This convection should help determine where the strongest instability develops. Surface dewpoints along and ahead of the front should be from the upper 50s to the lower 60s F. As surface heating takes place during the day, pockets of moderate instability appear likely to develop by afternoon from parts of central South Dakota southward into west-central Nebraska and Kansas. As low-level convergence increases along the front, surface-based thunderstorms are forecast to form. This convection should organize and move southeastward across parts the central and northern Plains during the late afternoon and early evening. MCS development will be possible. At this point, the two areas with the greatest potential appear to be in eastern South Dakota and in central Kansas. The models develop moderate instability in both of these areas. NAM forecast soundings at Aberdeen, SD show 0-6 km shear values in the 30 to 40 kt range while deep-layer shear is a bit stronger further south across Nebraska and Kansas. This should be sufficient for supercell development and large hail will be possible with cells that develop near the pockets of strongest instability. Due to the expected split in the instability field, have broken the significant hail probabilities into two areas. The first is in eastern South Dakota with the second in north-central Kansas and southwest Nebraska. Supercells will also have a potential for wind-damage and an isolated tornado threat. A more substantial wind damage threat could develop if cells can congeal into a persistent line segment during the early to mid evening. ...Upper Ohio Valley... West to southwest mid-level flow will be in place on Thursday from the Ohio Valley into the Northeast. At the surface, a front will advance eastward across upper Ohio Valley as a low develops along the front. Surface dewpoints ahead of the front should be in the mid 60s F allowing for moderate destabilization by afternoon. Convection is forecast to initiate along and ahead of the front during the afternoon from eastern Ohio into west-central Pennsylvania and southward into the Virginias. Although lapse rates are not expected to be that steep, forecast soundings do show 0-6 km shear values in the 30 to 40 kt range. For this reason, a few marginally severe storms may develop in the late afternoon with potential for strong wind gusts and hail. ...Eastern Carolinas... An upper-level trough will move eastward from the Tennessee Valley into the southern Appalachians on Thursday. At the surface, a cold front is forecast to move into the southern Appalachians. To the east of the front, surface dewpoints should be in the mid to upper 60s F. In response, a narrow corridor of moderate instability will be possible just ahead of the front by afternoon across the central and eastern Carolinas. Although deep-layer shear is forecast to be below 30 kt in most areas, steep low-level lapse rates near peak heating may be enough for marginally severe multicells. A few strong wind gusts will be the most likely hazard. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Broyles.. 08/14/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Wed Aug 14 2019 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe storms are expected across parts of the central and northern Plains on Thursday. Isolated severe storms are possible from Ohio into west-central Pennsylvania and across parts of the eastern Carolinas. ...Central and Northern Plains... West to northwest mid-level flow will be in place across the central U.S. on Thursday as a low-amplitude shortwave trough moves east-southeastward into the northern Plains. At the surface, a low will deepen across southwest Kansas as a cold front moves southeastward across eastern Colorado, western Nebraska and central South Dakota. Elevated convection should be ongoing in parts of the central Plains during the morning associated with the exit region of the low-level jet. This convection should help determine where the strongest instability develops. Surface dewpoints along and ahead of the front should be from the upper 50s to the lower 60s F. As surface heating takes place during the day, pockets of moderate instability appear likely to develop by afternoon from parts of central South Dakota southward into west-central Nebraska and Kansas. As low-level convergence increases along the front, surface-based thunderstorms are forecast to form. This convection should organize and move southeastward across parts the central and northern Plains during the late afternoon and early evening. MCS development will be possible. At this point, the two areas with the greatest potential appear to be in eastern South Dakota and in central Kansas. The models develop moderate instability in both of these areas. NAM forecast soundings at Aberdeen, SD show 0-6 km shear values in the 30 to 40 kt range while deep-layer shear is a bit stronger further south across Nebraska and Kansas. This should be sufficient for supercell development and large hail will be possible with cells that develop near the pockets of strongest instability. Due to the expected split in the instability field, have broken the significant hail probabilities into two areas. The first is in eastern South Dakota with the second in north-central Kansas and southwest Nebraska. Supercells will also have a potential for wind-damage and an isolated tornado threat. A more substantial wind damage threat could develop if cells can congeal into a persistent line segment during the early to mid evening. ...Upper Ohio Valley... West to southwest mid-level flow will be in place on Thursday from the Ohio Valley into the Northeast. At the surface, a front will advance eastward across upper Ohio Valley as a low develops along the front. Surface dewpoints ahead of the front should be in the mid 60s F allowing for moderate destabilization by afternoon. Convection is forecast to initiate along and ahead of the front during the afternoon from eastern Ohio into west-central Pennsylvania and southward into the Virginias. Although lapse rates are not expected to be that steep, forecast soundings do show 0-6 km shear values in the 30 to 40 kt range. For this reason, a few marginally severe storms may develop in the late afternoon with potential for strong wind gusts and hail. ...Eastern Carolinas... An upper-level trough will move eastward from the Tennessee Valley into the southern Appalachians on Thursday. At the surface, a cold front is forecast to move into the southern Appalachians. To the east of the front, surface dewpoints should be in the mid to upper 60s F. In response, a narrow corridor of moderate instability will be possible just ahead of the front by afternoon across the central and eastern Carolinas. Although deep-layer shear is forecast to be below 30 kt in most areas, steep low-level lapse rates near peak heating may be enough for marginally severe multicells. A few strong wind gusts will be the most likely hazard. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Broyles.. 08/14/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Wed Aug 14 2019 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe storms are expected across parts of the central and northern Plains on Thursday. Isolated severe storms are possible from Ohio into west-central Pennsylvania and across parts of the eastern Carolinas. ...Central and Northern Plains... West to northwest mid-level flow will be in place across the central U.S. on Thursday as a low-amplitude shortwave trough moves east-southeastward into the northern Plains. At the surface, a low will deepen across southwest Kansas as a cold front moves southeastward across eastern Colorado, western Nebraska and central South Dakota. Elevated convection should be ongoing in parts of the central Plains during the morning associated with the exit region of the low-level jet. This convection should help determine where the strongest instability develops. Surface dewpoints along and ahead of the front should be from the upper 50s to the lower 60s F. As surface heating takes place during the day, pockets of moderate instability appear likely to develop by afternoon from parts of central South Dakota southward into west-central Nebraska and Kansas. As low-level convergence increases along the front, surface-based thunderstorms are forecast to form. This convection should organize and move southeastward across parts the central and northern Plains during the late afternoon and early evening. MCS development will be possible. At this point, the two areas with the greatest potential appear to be in eastern South Dakota and in central Kansas. The models develop moderate instability in both of these areas. NAM forecast soundings at Aberdeen, SD show 0-6 km shear values in the 30 to 40 kt range while deep-layer shear is a bit stronger further south across Nebraska and Kansas. This should be sufficient for supercell development and large hail will be possible with cells that develop near the pockets of strongest instability. Due to the expected split in the instability field, have broken the significant hail probabilities into two areas. The first is in eastern South Dakota with the second in north-central Kansas and southwest Nebraska. Supercells will also have a potential for wind-damage and an isolated tornado threat. A more substantial wind damage threat could develop if cells can congeal into a persistent line segment during the early to mid evening. ...Upper Ohio Valley... West to southwest mid-level flow will be in place on Thursday from the Ohio Valley into the Northeast. At the surface, a front will advance eastward across upper Ohio Valley as a low develops along the front. Surface dewpoints ahead of the front should be in the mid 60s F allowing for moderate destabilization by afternoon. Convection is forecast to initiate along and ahead of the front during the afternoon from eastern Ohio into west-central Pennsylvania and southward into the Virginias. Although lapse rates are not expected to be that steep, forecast soundings do show 0-6 km shear values in the 30 to 40 kt range. For this reason, a few marginally severe storms may develop in the late afternoon with potential for strong wind gusts and hail. ...Eastern Carolinas... An upper-level trough will move eastward from the Tennessee Valley into the southern Appalachians on Thursday. At the surface, a cold front is forecast to move into the southern Appalachians. To the east of the front, surface dewpoints should be in the mid to upper 60s F. In response, a narrow corridor of moderate instability will be possible just ahead of the front by afternoon across the central and eastern Carolinas. Although deep-layer shear is forecast to be below 30 kt in most areas, steep low-level lapse rates near peak heating may be enough for marginally severe multicells. A few strong wind gusts will be the most likely hazard. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Broyles.. 08/14/2019 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 PM CDT Wed Aug 14 2019 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe storms are expected across parts of the central and northern Plains on Thursday. Isolated severe storms are possible from Ohio into west-central Pennsylvania and across parts of the eastern Carolinas. ...Central and Northern Plains... West to northwest mid-level flow will be in place across the central U.S. on Thursday as a low-amplitude shortwave trough moves east-southeastward into the northern Plains. At the surface, a low will deepen across southwest Kansas as a cold front moves southeastward across eastern Colorado, western Nebraska and central South Dakota. Elevated convection should be ongoing in parts of the central Plains during the morning associated with the exit region of the low-level jet. This convection should help determine where the strongest instability develops. Surface dewpoints along and ahead of the front should be from the upper 50s to the lower 60s F. As surface heating takes place during the day, pockets of moderate instability appear likely to develop by afternoon from parts of central South Dakota southward into west-central Nebraska and Kansas. As low-level convergence increases along the front, surface-based thunderstorms are forecast to form. This convection should organize and move southeastward across parts the central and northern Plains during the late afternoon and early evening. MCS development will be possible. At this point, the two areas with the greatest potential appear to be in eastern South Dakota and in central Kansas. The models develop moderate instability in both of these areas. NAM forecast soundings at Aberdeen, SD show 0-6 km shear values in the 30 to 40 kt range while deep-layer shear is a bit stronger further south across Nebraska and Kansas. This should be sufficient for supercell development and large hail will be possible with cells that develop near the pockets of strongest instability. Due to the expected split in the instability field, have broken the significant hail probabilities into two areas. The first is in eastern South Dakota with the second in north-central Kansas and southwest Nebraska. Supercells will also have a potential for wind-damage and an isolated tornado threat. A more substantial wind damage threat could develop if cells can congeal into a persistent line segment during the early to mid evening. ...Upper Ohio Valley... West to southwest mid-level flow will be in place on Thursday from the Ohio Valley into the Northeast. At the surface, a front will advance eastward across upper Ohio Valley as a low develops along the front. Surface dewpoints ahead of the front should be in the mid 60s F allowing for moderate destabilization by afternoon. Convection is forecast to initiate along and ahead of the front during the afternoon from eastern Ohio into west-central Pennsylvania and southward into the Virginias. Although lapse rates are not expected to be that steep, forecast soundings do show 0-6 km shear values in the 30 to 40 kt range. For this reason, a few marginally severe storms may develop in the late afternoon with potential for strong wind gusts and hail. ...Eastern Carolinas... An upper-level trough will move eastward from the Tennessee Valley into the southern Appalachians on Thursday. At the surface, a cold front is forecast to move into the southern Appalachians. To the east of the front, surface dewpoints should be in the mid to upper 60s F. In response, a narrow corridor of moderate instability will be possible just ahead of the front by afternoon across the central and eastern Carolinas. Although deep-layer shear is forecast to be below 30 kt in most areas, steep low-level lapse rates near peak heating may be enough for marginally severe multicells. A few strong wind gusts will be the most likely hazard. ...MAXIMUM RISK BY HAZARD... Tornado: 5% - Slight Wind: 15% - Slight Hail: 15% SIG - Slight ..Broyles.. 08/14/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Wed Aug 14 2019 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE CENTRAL/NORTHERN HIGH PLAINS... ...SUMMARY... Scattered severe thunderstorms with very large hail, a couple tornadoes, and damaging winds are possible across parts of the central and northern High Plains from late afternoon into tonight. ...Northern/central High Plains... Confidence in storm coverage and initiation corridors are lower today compared to yesterday. Surface dew points are drier this morning with 50s prevalent to low 60s in KS in the wake of yesterday's convective overturning. Nevertheless, persistent mid-level west-northwesterlies will maintain very steep lapse rates atop the residual boundary-layer moisture and should yield a plume of MLCAPE from 1500-2500 J/kg at peak heating from the Black Hills/eastern WY south across far eastern CO/western KS. Forcing for ascent will be rather weak near the higher terrain and southerly low-level flow dominates eastern CO at present. Convective initiation should be delayed until late afternoon and may be sparse in the central High Plains, with storm coverage beyond a cell or two highly questionable within the corridor most favorable for supercells. Still, effective bulk shear of 40-50 kt with relatively straight hodographs will support the risk of a couple supercells capable of producing isolated very large hail. The tornado threat will likely depend on a discrete cell interacting with the somewhat greater low-level shear/hodograph curvature expected near the CO/KS/NE border area along the east edge of the greater buoyancy. Somewhat greater confidence in convective initiation is across southeast MT/northeast WY owing to peripheral influence of a minor shortwave trough approaching from the Canadian Rockies. Isolated to perhaps scattered storms should develop along the northern extent of the buoyancy plume. There is some signal for upscale growth into a small, increasingly elevated MCS downstream across portions of western SD/NE tonight as a 25-35 kt nocturnal low-level jet develops across the Panhandles to southwest NE. Isolated severe wind and hail will remain possible into the early overnight. ...Central Gulf Coast to the Mid-Atlantic... The effective surface boundary, modulated by convective outflow, will continue to sag southward toward the Central Gulf Coast and southeastward toward the South/Mid-Atlantic coasts. The richer moisture (PW greater than 2 inches) and large buoyancy (MLCAPE of 2500-3500 J/kg) should be confined to the eastern Carolinas southwestward into the central Gulf Coast. Vertical shear will be very weak and boundary/storm mergers will largely drive isolated downburst potential. Somewhat stronger deep-layer shear is expected farther north toward Chesapeake Bay, which could compensate some for the weaker buoyancy and poor mid-level lapse rates. ...Northern IN vicinity... A diffuse surface front will provide a focus for thunderstorm development this afternoon, as a minor mid-level impulse approaches from southern WI. Lingering low-level moisture and surface heating will support MLCAPE of 1000-1500 J/kg, while deep-layer vertical shear will be at least marginally favorable for a couple organized/supercell storms. Very weak low-level flow will greatly limit hodograph size/SRH magnitude, but there will be modest vertical vorticity along the surface boundary. A couple of storms with hail/wind near severe criteria and a brief tornado are all possible. ..Grams/Leitman.. 08/14/2019 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Wed Aug 14 2019 Valid 141630Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS PARTS OF THE CENTRAL/NORTHERN HIGH PLAINS... ...SUMMARY... Scattered severe thunderstorms with very large hail, a couple tornadoes, and damaging winds are possible across parts of the central and northern High Plains from late afternoon into tonight. ...Northern/central High Plains... Confidence in storm coverage and initiation corridors are lower today compared to yesterday. Surface dew points are drier this morning with 50s prevalent to low 60s in KS in the wake of yesterday's convective overturning. Nevertheless, persistent mid-level west-northwesterlies will maintain very steep lapse rates atop the residual boundary-layer moisture and should yield a plume of MLCAPE from 1500-2500 J/kg at peak heating from the Black Hills/eastern WY south across far eastern CO/western KS. Forcing for ascent will be rather weak near the higher terrain and southerly low-level flow dominates eastern CO at present. Convective initiation should be delayed until late afternoon and may be sparse in the central High Plains, with storm coverage beyond a cell or two highly questionable within the corridor most favorable for supercells. Still, effective bulk shear of 40-50 kt with relatively straight hodographs will support the risk of a couple supercells capable of producing isolated very large hail. The tornado threat will likely depend on a discrete cell interacting with the somewhat greater low-level shear/hodograph curvature expected near the CO/KS/NE border area along the east edge of the greater buoyancy. Somewhat greater confidence in convective initiation is across southeast MT/northeast WY owing to peripheral influence of a minor shortwave trough approaching from the Canadian Rockies. Isolated to perhaps scattered storms should develop along the northern extent of the buoyancy plume. There is some signal for upscale growth into a small, increasingly elevated MCS downstream across portions of western SD/NE tonight as a 25-35 kt nocturnal low-level jet develops across the Panhandles to southwest NE. Isolated severe wind and hail will remain possible into the early overnight. ...Central Gulf Coast to the Mid-Atlantic... The effective surface boundary, modulated by convective outflow, will continue to sag southward toward the Central Gulf Coast and southeastward toward the South/Mid-Atlantic coasts. The richer moisture (PW greater than 2 inches) and large buoyancy (MLCAPE of 2500-3500 J/kg) should be confined to the eastern Carolinas southwestward into the central Gulf Coast. Vertical shear will be very weak and boundary/storm mergers will largely drive isolated downburst potential. Somewhat stronger deep-layer shear is expected farther north toward Chesapeake Bay, which could compensate some for the weaker buoyancy and poor mid-level lapse rates. ...Northern IN vicinity... A diffuse surface front will provide a focus for thunderstorm development this afternoon, as a minor mid-level impulse approaches from southern WI. Lingering low-level moisture and surface heating will support MLCAPE of 1000-1500 J/kg, while deep-layer vertical shear will be at least marginally favorable for a couple organized/supercell storms. Very weak low-level flow will greatly limit hodograph size/SRH magnitude, but there will be modest vertical vorticity along the surface boundary. A couple of storms with hail/wind near severe criteria and a brief tornado are all possible. ..Grams/Leitman.. 08/14/2019 Read more