Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0203 AM CDT Sat May 18 2024 Valid 181200Z - 191200Z ...NO CRITICAL AREAS... ...Synopsis... Mid level ridging will start to build into the central CONUS today with a series of troughs moving through the Northwest and northern Plains. At this time, dry fuels are concentrated across portions of the Southwest and southern High Plains. However, winds will be mostly light across this region on Saturday. Some dry and breezy (15 to 20 mph) conditions are possible across southern Arizona as mid-level flow strengthens, but fuels are not dry enough to support large fires at this time. ..Bentley.. 05/18/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Sat May 18 2024 Valid 191200Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF WESTERN AND CENTRAL KANSAS... ...SUMMARY... Severe thunderstorms are most likely across parts of Kansas Sunday afternoon and evening. Significant damaging gusts, large to very large hail, and a few tornadoes all appear possible. ...NE/KS/OK... A weak upper shortwave impulse over NE Sunday morning will quickly lift northeast. Some convection may be ongoing across NE/KS during the morning, but is forecast to quickly weaken/shift east. This early activity may suppress severe potential across northeast NE during the afternoon as airmass recovery is uncertain. By afternoon, another upper shortwave trough is forecast to eject from the southern/central Rockies into KS, and then the Lower MO Valley by Monday morning. This secondary shortwave trough will be the focus for the primary severe risk during the afternoon/evening. A surface dryline is forecast to extend southward from near the NE/KS/CO border into western KS and then near the OK/TX border. To the east of the dryline, dewpoints into the low/mid 60s are expected across OK into central/eastern KS (somewhat lower across northern KS and southern NE). Very steep midlevel lapse rates (greater than 8 C/km) will be in place. Capping will suppress convection until mid/late afternoon, when large-scale ascent increases amid strong heating and continued warm/moist advection. High-based storms along the dryline will initially pose a risk of large hail and damaging gusts. Forecast guidance (including HREF and CAMs) show a strong signal for upscale growth into an intense bow is possible across KS. Upscale growth is possible via consolidating outflow and an increasing low-level jet during the late afternoon/early evening. Significant gusts will be possible if this scenario evolves as expected. Large to very hail and a few tornadoes also will be possible. Hail greater than 2 inches in diameter will be possible early in convective evolution, but eastward extent of this risk is uncertain and dependent on storm mode. Severe potential southward along the dryline into western OK is more uncertain and conditional. If a storm can develop and be maintained, all severe hazards would be possible, particularly very large hail and damaging gusts. ...SD vicinity... Southerly low-level flow will transport mid/upper 50s F dewpoints northward into northern NE/SD and southern ND. A cold front is forecast to develop eastward during the late Sunday afternoon into Sunday night. Steep midlevel lapse rates will be in place, but an EML will likely limit a greater severe risk. Nevertheless, MUCAPE to around 1500 J/kg will support elevated convection ahead of the cold front. Isolated hail will be the main risk. However, if an organized line of storms can develop, some gusty winds also are possible. ...Lower MO Valley toward the Mid-MS Valley... Convection from NE/KS may dissipate over the area during the morning. However, a warm front is expected to slowly lift northward through the day, allowing from some airmass recovery and destabilization. Convection may redevelop near this boundary during the afternoon. This activity may produce marginally severe hail and gusty winds. ...FL... An upper trough from the Mid-Atlantic to the northern Gulf will shift east over the Atlantic on Sunday. A belt of enhanced west/southwesterly flow (30-40 kt at 700 mb) will overspread the FL peninsula ahead of the trough. Mid to upper 60s F surface dewpoints and strong heating will contribute to MLCAPE values around 1500-2500 J/kg. Steep low-level lapse rates will support isolated strong gusts in water-loaded downdrafts. Elongated/straight forecast hodographs and modest midlevel lapse rates (6.5-7 C/km) suggest isolated large hail also is possible. Effective shear around 30 kt suggests organized updrafts may be somewhat transient. If confidence increases regarding coverage of organized severe convection, higher probabilities may be needed in subsequent outlooks. ..Leitman.. 05/18/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Sat May 18 2024 Valid 191200Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF WESTERN AND CENTRAL KANSAS... ...SUMMARY... Severe thunderstorms are most likely across parts of Kansas Sunday afternoon and evening. Significant damaging gusts, large to very large hail, and a few tornadoes all appear possible. ...NE/KS/OK... A weak upper shortwave impulse over NE Sunday morning will quickly lift northeast. Some convection may be ongoing across NE/KS during the morning, but is forecast to quickly weaken/shift east. This early activity may suppress severe potential across northeast NE during the afternoon as airmass recovery is uncertain. By afternoon, another upper shortwave trough is forecast to eject from the southern/central Rockies into KS, and then the Lower MO Valley by Monday morning. This secondary shortwave trough will be the focus for the primary severe risk during the afternoon/evening. A surface dryline is forecast to extend southward from near the NE/KS/CO border into western KS and then near the OK/TX border. To the east of the dryline, dewpoints into the low/mid 60s are expected across OK into central/eastern KS (somewhat lower across northern KS and southern NE). Very steep midlevel lapse rates (greater than 8 C/km) will be in place. Capping will suppress convection until mid/late afternoon, when large-scale ascent increases amid strong heating and continued warm/moist advection. High-based storms along the dryline will initially pose a risk of large hail and damaging gusts. Forecast guidance (including HREF and CAMs) show a strong signal for upscale growth into an intense bow is possible across KS. Upscale growth is possible via consolidating outflow and an increasing low-level jet during the late afternoon/early evening. Significant gusts will be possible if this scenario evolves as expected. Large to very hail and a few tornadoes also will be possible. Hail greater than 2 inches in diameter will be possible early in convective evolution, but eastward extent of this risk is uncertain and dependent on storm mode. Severe potential southward along the dryline into western OK is more uncertain and conditional. If a storm can develop and be maintained, all severe hazards would be possible, particularly very large hail and damaging gusts. ...SD vicinity... Southerly low-level flow will transport mid/upper 50s F dewpoints northward into northern NE/SD and southern ND. A cold front is forecast to develop eastward during the late Sunday afternoon into Sunday night. Steep midlevel lapse rates will be in place, but an EML will likely limit a greater severe risk. Nevertheless, MUCAPE to around 1500 J/kg will support elevated convection ahead of the cold front. Isolated hail will be the main risk. However, if an organized line of storms can develop, some gusty winds also are possible. ...Lower MO Valley toward the Mid-MS Valley... Convection from NE/KS may dissipate over the area during the morning. However, a warm front is expected to slowly lift northward through the day, allowing from some airmass recovery and destabilization. Convection may redevelop near this boundary during the afternoon. This activity may produce marginally severe hail and gusty winds. ...FL... An upper trough from the Mid-Atlantic to the northern Gulf will shift east over the Atlantic on Sunday. A belt of enhanced west/southwesterly flow (30-40 kt at 700 mb) will overspread the FL peninsula ahead of the trough. Mid to upper 60s F surface dewpoints and strong heating will contribute to MLCAPE values around 1500-2500 J/kg. Steep low-level lapse rates will support isolated strong gusts in water-loaded downdrafts. Elongated/straight forecast hodographs and modest midlevel lapse rates (6.5-7 C/km) suggest isolated large hail also is possible. Effective shear around 30 kt suggests organized updrafts may be somewhat transient. If confidence increases regarding coverage of organized severe convection, higher probabilities may be needed in subsequent outlooks. ..Leitman.. 05/18/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Sat May 18 2024 Valid 191200Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF WESTERN AND CENTRAL KANSAS... ...SUMMARY... Severe thunderstorms are most likely across parts of Kansas Sunday afternoon and evening. Significant damaging gusts, large to very large hail, and a few tornadoes all appear possible. ...NE/KS/OK... A weak upper shortwave impulse over NE Sunday morning will quickly lift northeast. Some convection may be ongoing across NE/KS during the morning, but is forecast to quickly weaken/shift east. This early activity may suppress severe potential across northeast NE during the afternoon as airmass recovery is uncertain. By afternoon, another upper shortwave trough is forecast to eject from the southern/central Rockies into KS, and then the Lower MO Valley by Monday morning. This secondary shortwave trough will be the focus for the primary severe risk during the afternoon/evening. A surface dryline is forecast to extend southward from near the NE/KS/CO border into western KS and then near the OK/TX border. To the east of the dryline, dewpoints into the low/mid 60s are expected across OK into central/eastern KS (somewhat lower across northern KS and southern NE). Very steep midlevel lapse rates (greater than 8 C/km) will be in place. Capping will suppress convection until mid/late afternoon, when large-scale ascent increases amid strong heating and continued warm/moist advection. High-based storms along the dryline will initially pose a risk of large hail and damaging gusts. Forecast guidance (including HREF and CAMs) show a strong signal for upscale growth into an intense bow is possible across KS. Upscale growth is possible via consolidating outflow and an increasing low-level jet during the late afternoon/early evening. Significant gusts will be possible if this scenario evolves as expected. Large to very hail and a few tornadoes also will be possible. Hail greater than 2 inches in diameter will be possible early in convective evolution, but eastward extent of this risk is uncertain and dependent on storm mode. Severe potential southward along the dryline into western OK is more uncertain and conditional. If a storm can develop and be maintained, all severe hazards would be possible, particularly very large hail and damaging gusts. ...SD vicinity... Southerly low-level flow will transport mid/upper 50s F dewpoints northward into northern NE/SD and southern ND. A cold front is forecast to develop eastward during the late Sunday afternoon into Sunday night. Steep midlevel lapse rates will be in place, but an EML will likely limit a greater severe risk. Nevertheless, MUCAPE to around 1500 J/kg will support elevated convection ahead of the cold front. Isolated hail will be the main risk. However, if an organized line of storms can develop, some gusty winds also are possible. ...Lower MO Valley toward the Mid-MS Valley... Convection from NE/KS may dissipate over the area during the morning. However, a warm front is expected to slowly lift northward through the day, allowing from some airmass recovery and destabilization. Convection may redevelop near this boundary during the afternoon. This activity may produce marginally severe hail and gusty winds. ...FL... An upper trough from the Mid-Atlantic to the northern Gulf will shift east over the Atlantic on Sunday. A belt of enhanced west/southwesterly flow (30-40 kt at 700 mb) will overspread the FL peninsula ahead of the trough. Mid to upper 60s F surface dewpoints and strong heating will contribute to MLCAPE values around 1500-2500 J/kg. Steep low-level lapse rates will support isolated strong gusts in water-loaded downdrafts. Elongated/straight forecast hodographs and modest midlevel lapse rates (6.5-7 C/km) suggest isolated large hail also is possible. Effective shear around 30 kt suggests organized updrafts may be somewhat transient. If confidence increases regarding coverage of organized severe convection, higher probabilities may be needed in subsequent outlooks. ..Leitman.. 05/18/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1250 AM CDT Sat May 18 2024 Valid 191200Z - 201200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF WESTERN AND CENTRAL KANSAS... ...SUMMARY... Severe thunderstorms are most likely across parts of Kansas Sunday afternoon and evening. Significant damaging gusts, large to very large hail, and a few tornadoes all appear possible. ...NE/KS/OK... A weak upper shortwave impulse over NE Sunday morning will quickly lift northeast. Some convection may be ongoing across NE/KS during the morning, but is forecast to quickly weaken/shift east. This early activity may suppress severe potential across northeast NE during the afternoon as airmass recovery is uncertain. By afternoon, another upper shortwave trough is forecast to eject from the southern/central Rockies into KS, and then the Lower MO Valley by Monday morning. This secondary shortwave trough will be the focus for the primary severe risk during the afternoon/evening. A surface dryline is forecast to extend southward from near the NE/KS/CO border into western KS and then near the OK/TX border. To the east of the dryline, dewpoints into the low/mid 60s are expected across OK into central/eastern KS (somewhat lower across northern KS and southern NE). Very steep midlevel lapse rates (greater than 8 C/km) will be in place. Capping will suppress convection until mid/late afternoon, when large-scale ascent increases amid strong heating and continued warm/moist advection. High-based storms along the dryline will initially pose a risk of large hail and damaging gusts. Forecast guidance (including HREF and CAMs) show a strong signal for upscale growth into an intense bow is possible across KS. Upscale growth is possible via consolidating outflow and an increasing low-level jet during the late afternoon/early evening. Significant gusts will be possible if this scenario evolves as expected. Large to very hail and a few tornadoes also will be possible. Hail greater than 2 inches in diameter will be possible early in convective evolution, but eastward extent of this risk is uncertain and dependent on storm mode. Severe potential southward along the dryline into western OK is more uncertain and conditional. If a storm can develop and be maintained, all severe hazards would be possible, particularly very large hail and damaging gusts. ...SD vicinity... Southerly low-level flow will transport mid/upper 50s F dewpoints northward into northern NE/SD and southern ND. A cold front is forecast to develop eastward during the late Sunday afternoon into Sunday night. Steep midlevel lapse rates will be in place, but an EML will likely limit a greater severe risk. Nevertheless, MUCAPE to around 1500 J/kg will support elevated convection ahead of the cold front. Isolated hail will be the main risk. However, if an organized line of storms can develop, some gusty winds also are possible. ...Lower MO Valley toward the Mid-MS Valley... Convection from NE/KS may dissipate over the area during the morning. However, a warm front is expected to slowly lift northward through the day, allowing from some airmass recovery and destabilization. Convection may redevelop near this boundary during the afternoon. This activity may produce marginally severe hail and gusty winds. ...FL... An upper trough from the Mid-Atlantic to the northern Gulf will shift east over the Atlantic on Sunday. A belt of enhanced west/southwesterly flow (30-40 kt at 700 mb) will overspread the FL peninsula ahead of the trough. Mid to upper 60s F surface dewpoints and strong heating will contribute to MLCAPE values around 1500-2500 J/kg. Steep low-level lapse rates will support isolated strong gusts in water-loaded downdrafts. Elongated/straight forecast hodographs and modest midlevel lapse rates (6.5-7 C/km) suggest isolated large hail also is possible. Effective shear around 30 kt suggests organized updrafts may be somewhat transient. If confidence increases regarding coverage of organized severe convection, higher probabilities may be needed in subsequent outlooks. ..Leitman.. 05/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Sat May 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN NORTH FL AND SOUTH GA... ...SUMMARY... The most probable corridor for damaging winds is across the Florida Panhandle to the South Atlantic Coast, this morning into the afternoon. Isolated damaging winds and sporadic severe hail will be possible during the afternoon into the evening across much of the Southeast, and over parts of the Upper Midwest to eastern Kansas. ...Southeast... Increasing convective development is expected this morning across the northern Gulf Coast region from LA to the FL Panhandle. This should occur in response to isentropic ascent within the 700-mb baroclinic zone, amid a difluent upper flow regime in the right-rear quadrant of an intense upper jet advancing northeast over the Deep South to southern Appalachians. Outflow from a Friday evening MCS that decayed over south GA and north FL should serve as the primary downstream baroclinic zone later this morning as convection consolidates and spreads east-northeast. Amid a relatively nebulous surface pattern due to the lack of cyclogenesis, low-level flow outside of convective influences should remain weak. Southwesterly deep-layer speed shear will be favorable for occasional linear clustering through the morning into the afternoon before convection moves off the southern Atlantic Coast. Scattered damaging winds from strong to isolated severe wind gusts remain possible. Additional storms should form along the Florida Atlantic Coast sea breeze during the afternoon with an isolated severe threat possible. At least scattered afternoon thunderstorms are expected over the TN Valley to southern Appalachians ahead of the primary shortwave impulse embedded within the positive-tilt, southern-stream trough. Uncertainty exists over the degree of destabilization in the wake of the extensive morning convection farther south-southeast. With only moderate deep-layer shear expected between the trough and the mid-level jet near the Gulf Coast, have held severe wind/hail probabilities at level 1-MRGL. ...Upper Midwest to KS... A shortwave trough across the Prairie Provinces into the northern Great Plains will move east into far northwest ON by early Sunday. Attendant surface cyclone will track more north-northeastward as it occludes, with the trailing cold front shifting east of the Upper MS Valley and south in KS during the afternoon. Low-level convergence along the front should be sufficient for isolated to scattered thunderstorms, as a moderately unstable airmass with MLCAPE of 1000-2000 J/kg becomes established at peak heating. The bulk of strong mid-level west-southwesterlies will remain confined behind the front. Moderate deep-layer shear should overspread the Lake Superior region, as flow substantially weakens with southern extent. Isolated severe hail and damaging winds will be most likely across the Upper Midwest portion of the area. Locally strong to severe wind gusts and small hail may also occur within the weakly sheared environment along the front into KS. The severe threat will wane after dusk. ..Grams/Bentley.. 05/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Sat May 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN NORTH FL AND SOUTH GA... ...SUMMARY... The most probable corridor for damaging winds is across the Florida Panhandle to the South Atlantic Coast, this morning into the afternoon. Isolated damaging winds and sporadic severe hail will be possible during the afternoon into the evening across much of the Southeast, and over parts of the Upper Midwest to eastern Kansas. ...Southeast... Increasing convective development is expected this morning across the northern Gulf Coast region from LA to the FL Panhandle. This should occur in response to isentropic ascent within the 700-mb baroclinic zone, amid a difluent upper flow regime in the right-rear quadrant of an intense upper jet advancing northeast over the Deep South to southern Appalachians. Outflow from a Friday evening MCS that decayed over south GA and north FL should serve as the primary downstream baroclinic zone later this morning as convection consolidates and spreads east-northeast. Amid a relatively nebulous surface pattern due to the lack of cyclogenesis, low-level flow outside of convective influences should remain weak. Southwesterly deep-layer speed shear will be favorable for occasional linear clustering through the morning into the afternoon before convection moves off the southern Atlantic Coast. Scattered damaging winds from strong to isolated severe wind gusts remain possible. Additional storms should form along the Florida Atlantic Coast sea breeze during the afternoon with an isolated severe threat possible. At least scattered afternoon thunderstorms are expected over the TN Valley to southern Appalachians ahead of the primary shortwave impulse embedded within the positive-tilt, southern-stream trough. Uncertainty exists over the degree of destabilization in the wake of the extensive morning convection farther south-southeast. With only moderate deep-layer shear expected between the trough and the mid-level jet near the Gulf Coast, have held severe wind/hail probabilities at level 1-MRGL. ...Upper Midwest to KS... A shortwave trough across the Prairie Provinces into the northern Great Plains will move east into far northwest ON by early Sunday. Attendant surface cyclone will track more north-northeastward as it occludes, with the trailing cold front shifting east of the Upper MS Valley and south in KS during the afternoon. Low-level convergence along the front should be sufficient for isolated to scattered thunderstorms, as a moderately unstable airmass with MLCAPE of 1000-2000 J/kg becomes established at peak heating. The bulk of strong mid-level west-southwesterlies will remain confined behind the front. Moderate deep-layer shear should overspread the Lake Superior region, as flow substantially weakens with southern extent. Isolated severe hail and damaging winds will be most likely across the Upper Midwest portion of the area. Locally strong to severe wind gusts and small hail may also occur within the weakly sheared environment along the front into KS. The severe threat will wane after dusk. ..Grams/Bentley.. 05/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Sat May 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN NORTH FL AND SOUTH GA... ...SUMMARY... The most probable corridor for damaging winds is across the Florida Panhandle to the South Atlantic Coast, this morning into the afternoon. Isolated damaging winds and sporadic severe hail will be possible during the afternoon into the evening across much of the Southeast, and over parts of the Upper Midwest to eastern Kansas. ...Southeast... Increasing convective development is expected this morning across the northern Gulf Coast region from LA to the FL Panhandle. This should occur in response to isentropic ascent within the 700-mb baroclinic zone, amid a difluent upper flow regime in the right-rear quadrant of an intense upper jet advancing northeast over the Deep South to southern Appalachians. Outflow from a Friday evening MCS that decayed over south GA and north FL should serve as the primary downstream baroclinic zone later this morning as convection consolidates and spreads east-northeast. Amid a relatively nebulous surface pattern due to the lack of cyclogenesis, low-level flow outside of convective influences should remain weak. Southwesterly deep-layer speed shear will be favorable for occasional linear clustering through the morning into the afternoon before convection moves off the southern Atlantic Coast. Scattered damaging winds from strong to isolated severe wind gusts remain possible. Additional storms should form along the Florida Atlantic Coast sea breeze during the afternoon with an isolated severe threat possible. At least scattered afternoon thunderstorms are expected over the TN Valley to southern Appalachians ahead of the primary shortwave impulse embedded within the positive-tilt, southern-stream trough. Uncertainty exists over the degree of destabilization in the wake of the extensive morning convection farther south-southeast. With only moderate deep-layer shear expected between the trough and the mid-level jet near the Gulf Coast, have held severe wind/hail probabilities at level 1-MRGL. ...Upper Midwest to KS... A shortwave trough across the Prairie Provinces into the northern Great Plains will move east into far northwest ON by early Sunday. Attendant surface cyclone will track more north-northeastward as it occludes, with the trailing cold front shifting east of the Upper MS Valley and south in KS during the afternoon. Low-level convergence along the front should be sufficient for isolated to scattered thunderstorms, as a moderately unstable airmass with MLCAPE of 1000-2000 J/kg becomes established at peak heating. The bulk of strong mid-level west-southwesterlies will remain confined behind the front. Moderate deep-layer shear should overspread the Lake Superior region, as flow substantially weakens with southern extent. Isolated severe hail and damaging winds will be most likely across the Upper Midwest portion of the area. Locally strong to severe wind gusts and small hail may also occur within the weakly sheared environment along the front into KS. The severe threat will wane after dusk. ..Grams/Bentley.. 05/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Sat May 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN NORTH FL AND SOUTH GA... ...SUMMARY... The most probable corridor for damaging winds is across the Florida Panhandle to the South Atlantic Coast, this morning into the afternoon. Isolated damaging winds and sporadic severe hail will be possible during the afternoon into the evening across much of the Southeast, and over parts of the Upper Midwest to eastern Kansas. ...Southeast... Increasing convective development is expected this morning across the northern Gulf Coast region from LA to the FL Panhandle. This should occur in response to isentropic ascent within the 700-mb baroclinic zone, amid a difluent upper flow regime in the right-rear quadrant of an intense upper jet advancing northeast over the Deep South to southern Appalachians. Outflow from a Friday evening MCS that decayed over south GA and north FL should serve as the primary downstream baroclinic zone later this morning as convection consolidates and spreads east-northeast. Amid a relatively nebulous surface pattern due to the lack of cyclogenesis, low-level flow outside of convective influences should remain weak. Southwesterly deep-layer speed shear will be favorable for occasional linear clustering through the morning into the afternoon before convection moves off the southern Atlantic Coast. Scattered damaging winds from strong to isolated severe wind gusts remain possible. Additional storms should form along the Florida Atlantic Coast sea breeze during the afternoon with an isolated severe threat possible. At least scattered afternoon thunderstorms are expected over the TN Valley to southern Appalachians ahead of the primary shortwave impulse embedded within the positive-tilt, southern-stream trough. Uncertainty exists over the degree of destabilization in the wake of the extensive morning convection farther south-southeast. With only moderate deep-layer shear expected between the trough and the mid-level jet near the Gulf Coast, have held severe wind/hail probabilities at level 1-MRGL. ...Upper Midwest to KS... A shortwave trough across the Prairie Provinces into the northern Great Plains will move east into far northwest ON by early Sunday. Attendant surface cyclone will track more north-northeastward as it occludes, with the trailing cold front shifting east of the Upper MS Valley and south in KS during the afternoon. Low-level convergence along the front should be sufficient for isolated to scattered thunderstorms, as a moderately unstable airmass with MLCAPE of 1000-2000 J/kg becomes established at peak heating. The bulk of strong mid-level west-southwesterlies will remain confined behind the front. Moderate deep-layer shear should overspread the Lake Superior region, as flow substantially weakens with southern extent. Isolated severe hail and damaging winds will be most likely across the Upper Midwest portion of the area. Locally strong to severe wind gusts and small hail may also occur within the weakly sheared environment along the front into KS. The severe threat will wane after dusk. ..Grams/Bentley.. 05/18/2024 Read more

MD 0822 CONCERNING SEVERE THUNDERSTORM WATCH 255... FOR SOUTHEASTERN NORTH DAKOTA...NORTHEASTERN SOUTH DAKOTA...WEST CENTRAL/NORTHWESTERN MINNESOTA
Mesoscale Discussion 0822 NWS Storm Prediction Center Norman OK 1137 PM CDT Fri May 17 2024 Areas affected...southeastern North Dakota...northeastern South Dakota...west central/northwestern Minnesota Concerning...Severe Thunderstorm Watch 255... Valid 180437Z - 180600Z The severe weather threat for Severe Thunderstorm Watch 255 continues. SUMMARY...A few locally strong surface gusts remain possible with lingering convection spreading across and east of the Red River vicinity through 1-2 AM CDT, but the severe weather threat appears to have generally diminished. DISCUSSION...A convective outflow driven/enhanced cold front has advanced east of the the Red River, and southeastward through central South Dakota portions of the mid Missouri Valley. Ahead of this boundary, lower/mid-levels remain relatively dry as the boundary-layer continues to cool, resulting in diminishing instability. However, mid-level lapse rates are still steep enough to maintain sufficient instability to support continuing convective development in the presence of strong lift along a 30-50+ kt southerly 850 mb jet axis. While stronger convection is increasingly focused to the cool side of the surface front, thermodynamic profiles may remain conducive to occasional strong, but generally sub-severe, surface gusts in the more vigorous lingering convection as it gradually spreads eastward into the overnight hours. ..Kerr.. 05/18/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DLH...MPX...FGF...ABR...BIS... LAT...LON 48749430 47809432 46519536 45109688 44979819 45569872 46719792 48529655 48929584 48749430 Read more

WW 0256 Status Updates
STATUS REPORT ON WW 256 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 NE AAF TO 25 E TLH TO 25 S VLD TO 30 N CTY. REMAINING VALID PORTION OF WW 256 MAY BE ALLOWED TO EXPIRE AT 18/05Z. ..KERR..05/18/24 ATTN...WFO...JAX...TAE... STATUS REPORT FOR WT 256 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS FLC065-067-079-123-129-180500- FL . FLORIDA COUNTIES INCLUDED ARE JEFFERSON LAFAYETTE MADISON TAYLOR WAKULLA THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 256 TORNADO FL GA CW 172345Z - 180500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 256 NWS Storm Prediction Center Norman OK 745 PM EDT Fri May 17 2024 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of North Florida and Panhandle Southeast Georgia Coastal Waters * Effective this Friday night and Saturday morning from 745 PM until 100 AM EDT. * Primary threats include... A couple tornadoes possible Scattered damaging wind gusts to 70 mph possible Isolated large hail events to 1.5 inches in diameter possible SUMMARY...A broken band of severe thunderstorms will move east-southeast into the Florida Panhandle and adjacent portions of southeast Georgia and north Florida during this evening. In addition to the risk for a couple of tornadoes, severe gusts 60-70 mph resulting in wind damage will be possible with any embedded supercells or bowing segments, as they move east-southeast across the Watch area. The tornado watch area is approximately along and 35 statute miles north and south of a line from 25 miles south southeast of Brunswick GA to 45 miles southwest of Marianna FL. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and 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. && OTHER WATCH INFORMATION...CONTINUE...WW 253...WW 254...WW 255... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 30030. ...Smith Read more

WW 0255 Status Updates
STATUS REPORT ON WW 255 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 ESE MBG TO 35 SE JMS TO 15 NNW ROX. REMAINING VALID PORTION OF WW 255 MAY BE ALLOWED TO EXPIRE AT 18/05Z. ..KERR..05/18/24 ATTN...WFO...FGF...BIS...ABR... STATUS REPORT FOR WS 255 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MNC089-135-180500- MN . MINNESOTA COUNTIES INCLUDED ARE MARSHALL ROSEAU NDC021-045-073-081-180500- ND . NORTH DAKOTA COUNTIES INCLUDED ARE DICKEY LAMOURE RANSOM SARGENT SDC013-045-089-129-180500- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE BROWN EDMUNDS MCPHERSON Read more

WW 255 SEVERE TSTM MN ND SD 172230Z - 180500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 255 NWS Storm Prediction Center Norman OK 530 PM CDT Fri May 17 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Northwest Minnesota Eastern North Dakota Northern South Dakota * Effective this Friday afternoon from 530 PM until Midnight CDT. * Primary threats include... Scattered damaging wind gusts to 70 mph likely Isolated large hail events to 1.5 inches in diameter possible SUMMARY...A broken band of strong to severe thunderstorms will likely move east into the Watch area during the evening from the west. Severe gusts ranging from 60-70 mph and perhaps large hail are the main threats with the more intense thunderstorms. The severe thunderstorm watch area is approximately along and 85 statute miles east and west of a line from 20 miles north of Hallock MN to 20 miles east southeast of Mobridge SD. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU5). 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. && OTHER WATCH INFORMATION...CONTINUE...WW 253...WW 254... AVIATION...A few severe thunderstorms with hail surface and aloft to 1.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 400. Mean storm motion vector 25035. ...Smith Read more

WW 0256 Status Updates
STATUS REPORT ON WW 256 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 NNE AAF TO 10 NE TLH TO 10 WSW VLD TO 30 W SSI TO 35 ENE SSI. ..KERR..05/18/24 ATTN...WFO...JAX...TAE... STATUS REPORT FOR WT 256 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS FLC003-023-047-065-067-073-079-121-123-129-180440- FL . FLORIDA COUNTIES INCLUDED ARE BAKER COLUMBIA HAMILTON JEFFERSON LAFAYETTE LEON MADISON SUWANNEE TAYLOR WAKULLA GAC039-049-101-180440- GA . GEORGIA COUNTIES INCLUDED ARE CAMDEN CHARLTON ECHOLS AMZ450-180440- CW . ADJACENT COASTAL WATERS INCLUDED ARE Read more

WW 0255 Status Updates
STATUS REPORT ON WW 255 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 ESE MBG TO 35 SE JMS TO 35 NNW FAR TO 25 NW TVF TO 15 NNW ROX. ..KERR..05/18/24 ATTN...WFO...FGF...BIS...ABR... STATUS REPORT FOR WS 255 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MNC089-135-180440- MN . MINNESOTA COUNTIES INCLUDED ARE MARSHALL ROSEAU NDC021-045-073-081-180440- ND . NORTH DAKOTA COUNTIES INCLUDED ARE DICKEY LAMOURE RANSOM SARGENT SDC013-045-089-129-180440- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE BROWN EDMUNDS MCPHERSON WALWORTH Read more

MD 0821 CONCERNING SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY FOR SOUTHERN LOUISIANA AND FAR SOUTHERN MISSISSIPPI
Mesoscale Discussion 0821 NWS Storm Prediction Center Norman OK 0917 PM CDT Fri May 17 2024 Areas affected...southern Louisiana and far southern Mississippi Concerning...Severe potential...Severe Thunderstorm Watch likely Valid 180217Z - 180315Z Probability of Watch Issuance...80 percent SUMMARY...The severe weather threat will increase into the overnight hours across southern Louisiana and far southern Mississippi. DISCUSSION...A very moist Gulf airmass is in place across southern Louisiana this evening with a 18.5 mean mixing ratio on the 00Z LIX RAOB and mid to upper 70s dewpoints across most of the Delta. This deep moisture is supporting 2500 to 4000 J/kg MUCAPE (per SPC mesoanalysis) which should be maintained for much of the overnight period across the region. Strong shear (60 to 70 knots) will support supercells with a primary threat of large hail and damaging wind gusts. Weak low-level flow, per LIX 00Z RAOB and HDC VWP, combined with weak low-level lapse rates and at least partially elevated inflow bases, should limit the tornado threat during the overnight period. A severe thunderstorm watch is likely by 03Z to cover the overnight supercell threat. ..Bentley/Smith.. 05/18/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MOB...LIX...LCH... LAT...LON 29339361 29999288 30539157 30878975 30868887 30708861 30508843 30198841 29518871 29028896 28778959 28979075 29079140 29009212 28919270 28879291 29339361 Read more

MD 0820 CONCERNING TORNADO WATCH 256... FOR NORTHERN FLORIDA AND FAR SOUTHERN GEORGIA
Mesoscale Discussion 0820 NWS Storm Prediction Center Norman OK 0846 PM CDT Fri May 17 2024 Areas affected...Northern Florida and far southern Georgia Concerning...Tornado Watch 256... Valid 180146Z - 180315Z The severe weather threat for Tornado Watch 256 continues. SUMMARY...The severe weather threat will persist through the evening. DISCUSSION...Scattered supercells continue within tornado watch 256 and will continue to pose a threat for damaging wind gusts and potentially a tornado. Thus far the tornado threat has been limited, likely related to weak low-level lapse rates and lack of greater low-level updraft acceleration. Shear has also weakened with eastern extent and therefore, expect that the greater coverage threat for the remainder of the evening will be damaging wind gusts. Nonetheless, there is still some low-level cyclonic curvature and a brief tornado cannot be ruled out. ..Bentley.. 05/18/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...JAX...TAE... LAT...LON 30048464 30438475 31278292 31338149 30448146 30098252 30048371 30048464 Read more

MD 0819 CONCERNING SEVERE THUNDERSTORM WATCH 255... FOR SOUTHEASTERN NORTH DAKOTA AND NORTHEASTERN SOUTH DAKOTA
Mesoscale Discussion 0819 NWS Storm Prediction Center Norman OK 0807 PM CDT Fri May 17 2024 Areas affected...southeastern North Dakota and northeastern South Dakota Concerning...Severe Thunderstorm Watch 255... Valid 180107Z - 180300Z The severe weather threat for Severe Thunderstorm Watch 255 continues. SUMMARY...Peak surface gusts associated with ongoing thunderstorms have generally subsided, but could still increase once again across parts of northeastern South Dakota and southeastern North Dakota through 9-11 PM CDT. DISCUSSION...Based on cooling cloud tops, radar and lightning data, convection has undergone recent intensification in a cluster centered across south central North Dakota, and now shifting east of the Missouri River. This appears near the exit region of a seasonably strong high-level jet streak nosing into the northern high plains, which may help maintain convection as it spreads toward the Red River Valley this evening. Although probably unaccompanied by appreciable low-level moistening, the Rapid Refresh indicates considerable strengthening of south-southwesterly flow around 850 mb across central Nebraska toward the Watertown SD vicinity through 02-04Z. Forcing on the nose of this low-level jet may augment the upper support for convection, in the presence of limited instability, and downward mixing of this momentum could also support another uptick in potential for severe surface gusts. ..Kerr.. 05/18/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FGF...ABR...BIS... LAT...LON 45530047 46269974 46649874 47179771 46689651 45799689 45219839 45149975 45530047 Read more

WW 0256 Status Updates
STATUS REPORT ON WW 256 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 10 N AAF TO 5 NE TLH TO 15 WSW VLD TO 25 ESE AYS TO 35 ENE SSI. ..BENTLEY..05/18/24 ATTN...WFO...JAX...TAE... STATUS REPORT FOR WT 256 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS FLC003-023-047-065-067-073-079-121-123-129-180340- FL . FLORIDA COUNTIES INCLUDED ARE BAKER COLUMBIA HAMILTON JEFFERSON LAFAYETTE LEON MADISON SUWANNEE TAYLOR WAKULLA GAC039-049-101-180340- GA . GEORGIA COUNTIES INCLUDED ARE CAMDEN CHARLTON ECHOLS AMZ450-180340- CW . ADJACENT COASTAL WATERS INCLUDED ARE Read more