Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0111 AM CDT Mon Apr 21 2025 Valid 211200Z - 221200Z ...Synopsis... A mid-level trough will impinge on the East Coast as a second trough traverses the Northern Plains today. Surface lee troughing is expected across the central High Plains as a mass response to the passing of the Northern Plains trough, resulting in dry downslope flow. By afternoon, 15-20 mph sustained southwesterly surface winds will overlap with 15-20 percent RH over much of the Central High Plains. Elevated highlights are in place from far northeast New Mexico into central Nebraska, where fuels are dry. ..Squitieri.. 04/21/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0111 AM CDT Mon Apr 21 2025 Valid 211200Z - 221200Z ...Synopsis... A mid-level trough will impinge on the East Coast as a second trough traverses the Northern Plains today. Surface lee troughing is expected across the central High Plains as a mass response to the passing of the Northern Plains trough, resulting in dry downslope flow. By afternoon, 15-20 mph sustained southwesterly surface winds will overlap with 15-20 percent RH over much of the Central High Plains. Elevated highlights are in place from far northeast New Mexico into central Nebraska, where fuels are dry. ..Squitieri.. 04/21/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0111 AM CDT Mon Apr 21 2025 Valid 211200Z - 221200Z ...Synopsis... A mid-level trough will impinge on the East Coast as a second trough traverses the Northern Plains today. Surface lee troughing is expected across the central High Plains as a mass response to the passing of the Northern Plains trough, resulting in dry downslope flow. By afternoon, 15-20 mph sustained southwesterly surface winds will overlap with 15-20 percent RH over much of the Central High Plains. Elevated highlights are in place from far northeast New Mexico into central Nebraska, where fuels are dry. ..Squitieri.. 04/21/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0111 AM CDT Mon Apr 21 2025 Valid 211200Z - 221200Z ...Synopsis... A mid-level trough will impinge on the East Coast as a second trough traverses the Northern Plains today. Surface lee troughing is expected across the central High Plains as a mass response to the passing of the Northern Plains trough, resulting in dry downslope flow. By afternoon, 15-20 mph sustained southwesterly surface winds will overlap with 15-20 percent RH over much of the Central High Plains. Elevated highlights are in place from far northeast New Mexico into central Nebraska, where fuels are dry. ..Squitieri.. 04/21/2025 ...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 1254 AM CDT Mon Apr 21 2025 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN HIGH PLAINS INTO PARTS OF SOUTHERN KANSAS... ...SUMMARY... Isolated severe thunderstorms are possible on Tuesday across portions of the southern Plains. ...Synopsis... Low-amplitude west/southwest mid/upper flow will prevail across the south-central and southeast states on Tuesday. A belt of stronger westerlies aloft will reside across the northern tier of the U.S. as a series of upper troughs migrate eastward from the northern Plains to the Northeast. At the surface, low pressure over Quebec and an associated cold front will be located from the Hudson Valley into the NC/VA Piedmont. Further west, low-level moist advection on south/southeasterly low level flow will allow modified Gulf moisture to spread northward from the Lower MS Valley into the southern High Plains. ...Southern Plains to southern KS... Modest Gulf moisture will spread north and west through the day to near the NM/TX border and across much of OK into southern KS. Forecast guidance suggest a weak shortwave impulse will eject across the southern Rockies in modest west/southwesterly flow aloft. While height tendencies will remain neutral, precluding much in the way of surface cyclogenesis, a sharpening dryline is forecast to extend from southwest KS into the OK/TX Panhandles, then southward near the NM/TX border. Low-level moist advection beneath steep midlevel lapse rates will support moderate destabilization (MLCAPE 1500-2500 J/kg). While deep-layer flow will remain modest, vertically veering wind profiles will contribute to supercell wind profiles, with elongated/straight hodographs. Isolated supercells will pose a risk for large hail. Furthermore, strong heating will result in steep low-level lapse rates and a well mixed boundary layer, supporting isolated strong to severe outflow gusts. As a southerly low-level jet increases during the evening, some potential will exist for convection to develop into an eastward developing MCS. If this occurs, some severe potential could persist eastward away from the dryline into portions of western north Texas and western OK. ...IA/WI/IL... A stalled frontal boundary will extent across the Mid-MO Valley into southern WI. Modest moisture return and persistent isentropic ascent along this boundary may be sufficient for isolated thunderstorm development amid weak diurnal destabilization. Low to midlevel flow will remain rather weak, but rapidly increase above 700 mb, supporting effective shear magnitudes greater than 40 kt. Cold temperatures aloft (-17 C near 500 mb) will support MLCAPE to around 500 J/kg, and isolated convection could produce sporadic hail. ...Carolinas... A cold front associated with a surface low over Quebec will develop southeast across the Mid-Atlantic and Carolinas during the afternoon/evening. Strong heating of a modestly moist boundary layer ahead of the front will support a corridor of MLCAPE up to 1000-1500 J/kg. Weak low-level southwesterly flow will increase with height, support effective shear magnitudes up to 35 kt. This should be sufficient for a few stronger/organized cells. Steep low-level lapse rates and somewhat elongated hodographs suggest transient supercells capable of strong gusts and isolated hail will be possible. ..Leitman.. 04/21/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CDT Mon Apr 21 2025 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN HIGH PLAINS INTO PARTS OF SOUTHERN KANSAS... ...SUMMARY... Isolated severe thunderstorms are possible on Tuesday across portions of the southern Plains. ...Synopsis... Low-amplitude west/southwest mid/upper flow will prevail across the south-central and southeast states on Tuesday. A belt of stronger westerlies aloft will reside across the northern tier of the U.S. as a series of upper troughs migrate eastward from the northern Plains to the Northeast. At the surface, low pressure over Quebec and an associated cold front will be located from the Hudson Valley into the NC/VA Piedmont. Further west, low-level moist advection on south/southeasterly low level flow will allow modified Gulf moisture to spread northward from the Lower MS Valley into the southern High Plains. ...Southern Plains to southern KS... Modest Gulf moisture will spread north and west through the day to near the NM/TX border and across much of OK into southern KS. Forecast guidance suggest a weak shortwave impulse will eject across the southern Rockies in modest west/southwesterly flow aloft. While height tendencies will remain neutral, precluding much in the way of surface cyclogenesis, a sharpening dryline is forecast to extend from southwest KS into the OK/TX Panhandles, then southward near the NM/TX border. Low-level moist advection beneath steep midlevel lapse rates will support moderate destabilization (MLCAPE 1500-2500 J/kg). While deep-layer flow will remain modest, vertically veering wind profiles will contribute to supercell wind profiles, with elongated/straight hodographs. Isolated supercells will pose a risk for large hail. Furthermore, strong heating will result in steep low-level lapse rates and a well mixed boundary layer, supporting isolated strong to severe outflow gusts. As a southerly low-level jet increases during the evening, some potential will exist for convection to develop into an eastward developing MCS. If this occurs, some severe potential could persist eastward away from the dryline into portions of western north Texas and western OK. ...IA/WI/IL... A stalled frontal boundary will extent across the Mid-MO Valley into southern WI. Modest moisture return and persistent isentropic ascent along this boundary may be sufficient for isolated thunderstorm development amid weak diurnal destabilization. Low to midlevel flow will remain rather weak, but rapidly increase above 700 mb, supporting effective shear magnitudes greater than 40 kt. Cold temperatures aloft (-17 C near 500 mb) will support MLCAPE to around 500 J/kg, and isolated convection could produce sporadic hail. ...Carolinas... A cold front associated with a surface low over Quebec will develop southeast across the Mid-Atlantic and Carolinas during the afternoon/evening. Strong heating of a modestly moist boundary layer ahead of the front will support a corridor of MLCAPE up to 1000-1500 J/kg. Weak low-level southwesterly flow will increase with height, support effective shear magnitudes up to 35 kt. This should be sufficient for a few stronger/organized cells. Steep low-level lapse rates and somewhat elongated hodographs suggest transient supercells capable of strong gusts and isolated hail will be possible. ..Leitman.. 04/21/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CDT Mon Apr 21 2025 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN HIGH PLAINS INTO PARTS OF SOUTHERN KANSAS... ...SUMMARY... Isolated severe thunderstorms are possible on Tuesday across portions of the southern Plains. ...Synopsis... Low-amplitude west/southwest mid/upper flow will prevail across the south-central and southeast states on Tuesday. A belt of stronger westerlies aloft will reside across the northern tier of the U.S. as a series of upper troughs migrate eastward from the northern Plains to the Northeast. At the surface, low pressure over Quebec and an associated cold front will be located from the Hudson Valley into the NC/VA Piedmont. Further west, low-level moist advection on south/southeasterly low level flow will allow modified Gulf moisture to spread northward from the Lower MS Valley into the southern High Plains. ...Southern Plains to southern KS... Modest Gulf moisture will spread north and west through the day to near the NM/TX border and across much of OK into southern KS. Forecast guidance suggest a weak shortwave impulse will eject across the southern Rockies in modest west/southwesterly flow aloft. While height tendencies will remain neutral, precluding much in the way of surface cyclogenesis, a sharpening dryline is forecast to extend from southwest KS into the OK/TX Panhandles, then southward near the NM/TX border. Low-level moist advection beneath steep midlevel lapse rates will support moderate destabilization (MLCAPE 1500-2500 J/kg). While deep-layer flow will remain modest, vertically veering wind profiles will contribute to supercell wind profiles, with elongated/straight hodographs. Isolated supercells will pose a risk for large hail. Furthermore, strong heating will result in steep low-level lapse rates and a well mixed boundary layer, supporting isolated strong to severe outflow gusts. As a southerly low-level jet increases during the evening, some potential will exist for convection to develop into an eastward developing MCS. If this occurs, some severe potential could persist eastward away from the dryline into portions of western north Texas and western OK. ...IA/WI/IL... A stalled frontal boundary will extent across the Mid-MO Valley into southern WI. Modest moisture return and persistent isentropic ascent along this boundary may be sufficient for isolated thunderstorm development amid weak diurnal destabilization. Low to midlevel flow will remain rather weak, but rapidly increase above 700 mb, supporting effective shear magnitudes greater than 40 kt. Cold temperatures aloft (-17 C near 500 mb) will support MLCAPE to around 500 J/kg, and isolated convection could produce sporadic hail. ...Carolinas... A cold front associated with a surface low over Quebec will develop southeast across the Mid-Atlantic and Carolinas during the afternoon/evening. Strong heating of a modestly moist boundary layer ahead of the front will support a corridor of MLCAPE up to 1000-1500 J/kg. Weak low-level southwesterly flow will increase with height, support effective shear magnitudes up to 35 kt. This should be sufficient for a few stronger/organized cells. Steep low-level lapse rates and somewhat elongated hodographs suggest transient supercells capable of strong gusts and isolated hail will be possible. ..Leitman.. 04/21/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CDT Mon Apr 21 2025 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN HIGH PLAINS INTO PARTS OF SOUTHERN KANSAS... ...SUMMARY... Isolated severe thunderstorms are possible on Tuesday across portions of the southern Plains. ...Synopsis... Low-amplitude west/southwest mid/upper flow will prevail across the south-central and southeast states on Tuesday. A belt of stronger westerlies aloft will reside across the northern tier of the U.S. as a series of upper troughs migrate eastward from the northern Plains to the Northeast. At the surface, low pressure over Quebec and an associated cold front will be located from the Hudson Valley into the NC/VA Piedmont. Further west, low-level moist advection on south/southeasterly low level flow will allow modified Gulf moisture to spread northward from the Lower MS Valley into the southern High Plains. ...Southern Plains to southern KS... Modest Gulf moisture will spread north and west through the day to near the NM/TX border and across much of OK into southern KS. Forecast guidance suggest a weak shortwave impulse will eject across the southern Rockies in modest west/southwesterly flow aloft. While height tendencies will remain neutral, precluding much in the way of surface cyclogenesis, a sharpening dryline is forecast to extend from southwest KS into the OK/TX Panhandles, then southward near the NM/TX border. Low-level moist advection beneath steep midlevel lapse rates will support moderate destabilization (MLCAPE 1500-2500 J/kg). While deep-layer flow will remain modest, vertically veering wind profiles will contribute to supercell wind profiles, with elongated/straight hodographs. Isolated supercells will pose a risk for large hail. Furthermore, strong heating will result in steep low-level lapse rates and a well mixed boundary layer, supporting isolated strong to severe outflow gusts. As a southerly low-level jet increases during the evening, some potential will exist for convection to develop into an eastward developing MCS. If this occurs, some severe potential could persist eastward away from the dryline into portions of western north Texas and western OK. ...IA/WI/IL... A stalled frontal boundary will extent across the Mid-MO Valley into southern WI. Modest moisture return and persistent isentropic ascent along this boundary may be sufficient for isolated thunderstorm development amid weak diurnal destabilization. Low to midlevel flow will remain rather weak, but rapidly increase above 700 mb, supporting effective shear magnitudes greater than 40 kt. Cold temperatures aloft (-17 C near 500 mb) will support MLCAPE to around 500 J/kg, and isolated convection could produce sporadic hail. ...Carolinas... A cold front associated with a surface low over Quebec will develop southeast across the Mid-Atlantic and Carolinas during the afternoon/evening. Strong heating of a modestly moist boundary layer ahead of the front will support a corridor of MLCAPE up to 1000-1500 J/kg. Weak low-level southwesterly flow will increase with height, support effective shear magnitudes up to 35 kt. This should be sufficient for a few stronger/organized cells. Steep low-level lapse rates and somewhat elongated hodographs suggest transient supercells capable of strong gusts and isolated hail will be possible. ..Leitman.. 04/21/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CDT Mon Apr 21 2025 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN HIGH PLAINS INTO PARTS OF SOUTHERN KANSAS... ...SUMMARY... Isolated severe thunderstorms are possible on Tuesday across portions of the southern Plains. ...Synopsis... Low-amplitude west/southwest mid/upper flow will prevail across the south-central and southeast states on Tuesday. A belt of stronger westerlies aloft will reside across the northern tier of the U.S. as a series of upper troughs migrate eastward from the northern Plains to the Northeast. At the surface, low pressure over Quebec and an associated cold front will be located from the Hudson Valley into the NC/VA Piedmont. Further west, low-level moist advection on south/southeasterly low level flow will allow modified Gulf moisture to spread northward from the Lower MS Valley into the southern High Plains. ...Southern Plains to southern KS... Modest Gulf moisture will spread north and west through the day to near the NM/TX border and across much of OK into southern KS. Forecast guidance suggest a weak shortwave impulse will eject across the southern Rockies in modest west/southwesterly flow aloft. While height tendencies will remain neutral, precluding much in the way of surface cyclogenesis, a sharpening dryline is forecast to extend from southwest KS into the OK/TX Panhandles, then southward near the NM/TX border. Low-level moist advection beneath steep midlevel lapse rates will support moderate destabilization (MLCAPE 1500-2500 J/kg). While deep-layer flow will remain modest, vertically veering wind profiles will contribute to supercell wind profiles, with elongated/straight hodographs. Isolated supercells will pose a risk for large hail. Furthermore, strong heating will result in steep low-level lapse rates and a well mixed boundary layer, supporting isolated strong to severe outflow gusts. As a southerly low-level jet increases during the evening, some potential will exist for convection to develop into an eastward developing MCS. If this occurs, some severe potential could persist eastward away from the dryline into portions of western north Texas and western OK. ...IA/WI/IL... A stalled frontal boundary will extent across the Mid-MO Valley into southern WI. Modest moisture return and persistent isentropic ascent along this boundary may be sufficient for isolated thunderstorm development amid weak diurnal destabilization. Low to midlevel flow will remain rather weak, but rapidly increase above 700 mb, supporting effective shear magnitudes greater than 40 kt. Cold temperatures aloft (-17 C near 500 mb) will support MLCAPE to around 500 J/kg, and isolated convection could produce sporadic hail. ...Carolinas... A cold front associated with a surface low over Quebec will develop southeast across the Mid-Atlantic and Carolinas during the afternoon/evening. Strong heating of a modestly moist boundary layer ahead of the front will support a corridor of MLCAPE up to 1000-1500 J/kg. Weak low-level southwesterly flow will increase with height, support effective shear magnitudes up to 35 kt. This should be sufficient for a few stronger/organized cells. Steep low-level lapse rates and somewhat elongated hodographs suggest transient supercells capable of strong gusts and isolated hail will be possible. ..Leitman.. 04/21/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CDT Mon Apr 21 2025 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN HIGH PLAINS INTO PARTS OF SOUTHERN KANSAS... ...SUMMARY... Isolated severe thunderstorms are possible on Tuesday across portions of the southern Plains. ...Synopsis... Low-amplitude west/southwest mid/upper flow will prevail across the south-central and southeast states on Tuesday. A belt of stronger westerlies aloft will reside across the northern tier of the U.S. as a series of upper troughs migrate eastward from the northern Plains to the Northeast. At the surface, low pressure over Quebec and an associated cold front will be located from the Hudson Valley into the NC/VA Piedmont. Further west, low-level moist advection on south/southeasterly low level flow will allow modified Gulf moisture to spread northward from the Lower MS Valley into the southern High Plains. ...Southern Plains to southern KS... Modest Gulf moisture will spread north and west through the day to near the NM/TX border and across much of OK into southern KS. Forecast guidance suggest a weak shortwave impulse will eject across the southern Rockies in modest west/southwesterly flow aloft. While height tendencies will remain neutral, precluding much in the way of surface cyclogenesis, a sharpening dryline is forecast to extend from southwest KS into the OK/TX Panhandles, then southward near the NM/TX border. Low-level moist advection beneath steep midlevel lapse rates will support moderate destabilization (MLCAPE 1500-2500 J/kg). While deep-layer flow will remain modest, vertically veering wind profiles will contribute to supercell wind profiles, with elongated/straight hodographs. Isolated supercells will pose a risk for large hail. Furthermore, strong heating will result in steep low-level lapse rates and a well mixed boundary layer, supporting isolated strong to severe outflow gusts. As a southerly low-level jet increases during the evening, some potential will exist for convection to develop into an eastward developing MCS. If this occurs, some severe potential could persist eastward away from the dryline into portions of western north Texas and western OK. ...IA/WI/IL... A stalled frontal boundary will extent across the Mid-MO Valley into southern WI. Modest moisture return and persistent isentropic ascent along this boundary may be sufficient for isolated thunderstorm development amid weak diurnal destabilization. Low to midlevel flow will remain rather weak, but rapidly increase above 700 mb, supporting effective shear magnitudes greater than 40 kt. Cold temperatures aloft (-17 C near 500 mb) will support MLCAPE to around 500 J/kg, and isolated convection could produce sporadic hail. ...Carolinas... A cold front associated with a surface low over Quebec will develop southeast across the Mid-Atlantic and Carolinas during the afternoon/evening. Strong heating of a modestly moist boundary layer ahead of the front will support a corridor of MLCAPE up to 1000-1500 J/kg. Weak low-level southwesterly flow will increase with height, support effective shear magnitudes up to 35 kt. This should be sufficient for a few stronger/organized cells. Steep low-level lapse rates and somewhat elongated hodographs suggest transient supercells capable of strong gusts and isolated hail will be possible. ..Leitman.. 04/21/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CDT Mon Apr 21 2025 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN HIGH PLAINS INTO PARTS OF SOUTHERN KANSAS... ...SUMMARY... Isolated severe thunderstorms are possible on Tuesday across portions of the southern Plains. ...Synopsis... Low-amplitude west/southwest mid/upper flow will prevail across the south-central and southeast states on Tuesday. A belt of stronger westerlies aloft will reside across the northern tier of the U.S. as a series of upper troughs migrate eastward from the northern Plains to the Northeast. At the surface, low pressure over Quebec and an associated cold front will be located from the Hudson Valley into the NC/VA Piedmont. Further west, low-level moist advection on south/southeasterly low level flow will allow modified Gulf moisture to spread northward from the Lower MS Valley into the southern High Plains. ...Southern Plains to southern KS... Modest Gulf moisture will spread north and west through the day to near the NM/TX border and across much of OK into southern KS. Forecast guidance suggest a weak shortwave impulse will eject across the southern Rockies in modest west/southwesterly flow aloft. While height tendencies will remain neutral, precluding much in the way of surface cyclogenesis, a sharpening dryline is forecast to extend from southwest KS into the OK/TX Panhandles, then southward near the NM/TX border. Low-level moist advection beneath steep midlevel lapse rates will support moderate destabilization (MLCAPE 1500-2500 J/kg). While deep-layer flow will remain modest, vertically veering wind profiles will contribute to supercell wind profiles, with elongated/straight hodographs. Isolated supercells will pose a risk for large hail. Furthermore, strong heating will result in steep low-level lapse rates and a well mixed boundary layer, supporting isolated strong to severe outflow gusts. As a southerly low-level jet increases during the evening, some potential will exist for convection to develop into an eastward developing MCS. If this occurs, some severe potential could persist eastward away from the dryline into portions of western north Texas and western OK. ...IA/WI/IL... A stalled frontal boundary will extent across the Mid-MO Valley into southern WI. Modest moisture return and persistent isentropic ascent along this boundary may be sufficient for isolated thunderstorm development amid weak diurnal destabilization. Low to midlevel flow will remain rather weak, but rapidly increase above 700 mb, supporting effective shear magnitudes greater than 40 kt. Cold temperatures aloft (-17 C near 500 mb) will support MLCAPE to around 500 J/kg, and isolated convection could produce sporadic hail. ...Carolinas... A cold front associated with a surface low over Quebec will develop southeast across the Mid-Atlantic and Carolinas during the afternoon/evening. Strong heating of a modestly moist boundary layer ahead of the front will support a corridor of MLCAPE up to 1000-1500 J/kg. Weak low-level southwesterly flow will increase with height, support effective shear magnitudes up to 35 kt. This should be sufficient for a few stronger/organized cells. Steep low-level lapse rates and somewhat elongated hodographs suggest transient supercells capable of strong gusts and isolated hail will be possible. ..Leitman.. 04/21/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1254 AM CDT Mon Apr 21 2025 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN HIGH PLAINS INTO PARTS OF SOUTHERN KANSAS... ...SUMMARY... Isolated severe thunderstorms are possible on Tuesday across portions of the southern Plains. ...Synopsis... Low-amplitude west/southwest mid/upper flow will prevail across the south-central and southeast states on Tuesday. A belt of stronger westerlies aloft will reside across the northern tier of the U.S. as a series of upper troughs migrate eastward from the northern Plains to the Northeast. At the surface, low pressure over Quebec and an associated cold front will be located from the Hudson Valley into the NC/VA Piedmont. Further west, low-level moist advection on south/southeasterly low level flow will allow modified Gulf moisture to spread northward from the Lower MS Valley into the southern High Plains. ...Southern Plains to southern KS... Modest Gulf moisture will spread north and west through the day to near the NM/TX border and across much of OK into southern KS. Forecast guidance suggest a weak shortwave impulse will eject across the southern Rockies in modest west/southwesterly flow aloft. While height tendencies will remain neutral, precluding much in the way of surface cyclogenesis, a sharpening dryline is forecast to extend from southwest KS into the OK/TX Panhandles, then southward near the NM/TX border. Low-level moist advection beneath steep midlevel lapse rates will support moderate destabilization (MLCAPE 1500-2500 J/kg). While deep-layer flow will remain modest, vertically veering wind profiles will contribute to supercell wind profiles, with elongated/straight hodographs. Isolated supercells will pose a risk for large hail. Furthermore, strong heating will result in steep low-level lapse rates and a well mixed boundary layer, supporting isolated strong to severe outflow gusts. As a southerly low-level jet increases during the evening, some potential will exist for convection to develop into an eastward developing MCS. If this occurs, some severe potential could persist eastward away from the dryline into portions of western north Texas and western OK. ...IA/WI/IL... A stalled frontal boundary will extent across the Mid-MO Valley into southern WI. Modest moisture return and persistent isentropic ascent along this boundary may be sufficient for isolated thunderstorm development amid weak diurnal destabilization. Low to midlevel flow will remain rather weak, but rapidly increase above 700 mb, supporting effective shear magnitudes greater than 40 kt. Cold temperatures aloft (-17 C near 500 mb) will support MLCAPE to around 500 J/kg, and isolated convection could produce sporadic hail. ...Carolinas... A cold front associated with a surface low over Quebec will develop southeast across the Mid-Atlantic and Carolinas during the afternoon/evening. Strong heating of a modestly moist boundary layer ahead of the front will support a corridor of MLCAPE up to 1000-1500 J/kg. Weak low-level southwesterly flow will increase with height, support effective shear magnitudes up to 35 kt. This should be sufficient for a few stronger/organized cells. Steep low-level lapse rates and somewhat elongated hodographs suggest transient supercells capable of strong gusts and isolated hail will be possible. ..Leitman.. 04/21/2025 Read more

MD 0510 CONCERNING TORNADO WATCH 156...158... FOR EAST ARKANSAS...NORTHWEST TENNESSEE...FAR WEST KENTUCKY...SOUTHEAST ILLINOIS...AND SOUTHWEST INDIANA
Mesoscale Discussion 0510 NWS Storm Prediction Center Norman OK 1144 PM CDT Sun Apr 20 2025 Areas affected...east Arkansas...northwest Tennessee...far west Kentucky...southeast Illinois...and southwest Indiana Concerning...Tornado Watch 156...158... Valid 210444Z - 210615Z The severe weather threat for Tornado Watch 156, 158 continues. SUMMARY...Thunderstorms will continue to slowly move east overnight. The tornado threat in Arkansas has sufficiently diminished to allow Tornado Watch #156 to expire at 12 AM CDT. Strong low-level flow may support a brief tornado or severe wind gust across Tornado Watch #158. DISCUSSION...A long-lived, mixed-mode convective line continues to move east across Arkansas, Missouri, and Illinois late this evening. Despite a favorable kinematic environment (0-1 km shear of 40-50 knots and 0-1 km SRH between 300-500 m2/s2), increasing convective inhibition and decreasing CAPE have resulted in a general decreasing trend in convective intensity. With the upper-/mid-level forcing moving farther away, this general decrease in intensity is expected to continue. Given the overall decrease in intensity, especially across Arkansas, Tornado Watch #156 will be allowed to expire at 12 AM CDT. Farther east/north in Tornado Watch #158, the strength of the kinematic environment may support a brief tornado or wind gust, despite the increasingly hostile thermodynamic environment. ..Marsh.. 04/21/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...OHX...IND...PAH...ILX...MEG...JAN...LSX...LZK... LAT...LON 33869233 36578960 37468906 39148903 38748705 36458803 34459015 33279176 33869233 MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

WW 0158 Status Updates
STATUS REPORT ON WW 158 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 N MEM TO 25 SSW PAH TO 30 W EVV TO 40 SW BMG. ..BROYLES..04/21/25 ATTN...WFO...ILX...PAH...MEG... STATUS REPORT FOR WT 158 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC069-210640- IL . ILLINOIS COUNTIES INCLUDED ARE HARDIN INC051-129-163-210640- IN . INDIANA COUNTIES INCLUDED ARE GIBSON POSEY VANDERBURGH KYC039-055-083-101-105-139-143-145-157-225-210640- KY . KENTUCKY COUNTIES INCLUDED ARE CARLISLE CRITTENDEN GRAVES HENDERSON HICKMAN LIVINGSTON LYON MCCRACKEN MARSHALL UNION Read more

WW 0158 Status Updates
STATUS REPORT ON WW 158 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 N MEM TO 25 SSW PAH TO 30 W EVV TO 40 SW BMG. ..BROYLES..04/21/25 ATTN...WFO...ILX...PAH...MEG... STATUS REPORT FOR WT 158 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS ILC069-210640- IL . ILLINOIS COUNTIES INCLUDED ARE HARDIN INC051-129-163-210640- IN . INDIANA COUNTIES INCLUDED ARE GIBSON POSEY VANDERBURGH KYC039-055-083-101-105-139-143-145-157-225-210640- KY . KENTUCKY COUNTIES INCLUDED ARE CARLISLE CRITTENDEN GRAVES HENDERSON HICKMAN LIVINGSTON LYON MCCRACKEN MARSHALL UNION Read more

WW 158 TORNADO IL IN KY TN 210250Z - 210900Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 158 NWS Storm Prediction Center Norman OK 950 PM CDT Sun Apr 20 2025 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Southern Illinois Southwest Indiana Western Kentucky Western Tennessee * Effective this Sunday night and Monday morning from 950 PM until 400 AM CDT. * Primary threats include... A couple tornadoes possible Isolated damaging wind gusts to 70 mph possible SUMMARY...The potential for severe thunderstorms, including a damaging wind and tornado risk, will develop east-northeastward through late evening and overnight, but generally on an increasingly isolated basis. The tornado watch area is approximately along and 30 statute miles east and west of a line from 150 miles north northeast of Paducah KY to 45 miles south southwest of Dyersburg TN. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU8). 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 155...WW 156...WW 157... AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 23030. ...Guyer Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1228 AM CDT Mon Apr 21 2025 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY AND CENTRAL GULF STATES... ...SUMMARY... A few strong storms are possible across the upper Ohio Valley and across portions of the central Gulf States. Gusty winds and marginally severe hail are the primary risks. ...Upper Ohio Valley... Mid-MS Valley short-wave trough is forecast to eject into the upper Great Lakes region by mid day as 70+kt 500mb speed max translates across northern IN into southern ON. 500mb wind fields will strengthen across the upper OH Valley in response to this feature as heights are suppressed ahead of the short wave. Latest model guidance suggests the associated cold front will surge into western OH/KY by 18z, subsequently advancing into western PA later in the evening. Modest boundary-layer heating should contribute to adequate buoyancy for robust updrafts, and scattered convection should develop ahead of the front as temperatures warm through the 70s. Gusty winds may accompany this activity, along with some risk for marginally severe hail. ...Central Gulf States... Synoptic front will trail across the TN Valley through the central Gulf States today serving as the focus for thunderstorms as convective temperatures are breached along this weakly-forced boundary. While 0-6km bulk shear should only be modest across this region, seasonally high PW values and MLCAPE in excess of 1500 J/kg suggest some risk for gusty winds and hail. Boundary-layer heating should prove instrumental in convective updraft strength today. ..Darrow/Squitieri.. 04/21/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1228 AM CDT Mon Apr 21 2025 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY AND CENTRAL GULF STATES... ...SUMMARY... A few strong storms are possible across the upper Ohio Valley and across portions of the central Gulf States. Gusty winds and marginally severe hail are the primary risks. ...Upper Ohio Valley... Mid-MS Valley short-wave trough is forecast to eject into the upper Great Lakes region by mid day as 70+kt 500mb speed max translates across northern IN into southern ON. 500mb wind fields will strengthen across the upper OH Valley in response to this feature as heights are suppressed ahead of the short wave. Latest model guidance suggests the associated cold front will surge into western OH/KY by 18z, subsequently advancing into western PA later in the evening. Modest boundary-layer heating should contribute to adequate buoyancy for robust updrafts, and scattered convection should develop ahead of the front as temperatures warm through the 70s. Gusty winds may accompany this activity, along with some risk for marginally severe hail. ...Central Gulf States... Synoptic front will trail across the TN Valley through the central Gulf States today serving as the focus for thunderstorms as convective temperatures are breached along this weakly-forced boundary. While 0-6km bulk shear should only be modest across this region, seasonally high PW values and MLCAPE in excess of 1500 J/kg suggest some risk for gusty winds and hail. Boundary-layer heating should prove instrumental in convective updraft strength today. ..Darrow/Squitieri.. 04/21/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1228 AM CDT Mon Apr 21 2025 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY AND CENTRAL GULF STATES... ...SUMMARY... A few strong storms are possible across the upper Ohio Valley and across portions of the central Gulf States. Gusty winds and marginally severe hail are the primary risks. ...Upper Ohio Valley... Mid-MS Valley short-wave trough is forecast to eject into the upper Great Lakes region by mid day as 70+kt 500mb speed max translates across northern IN into southern ON. 500mb wind fields will strengthen across the upper OH Valley in response to this feature as heights are suppressed ahead of the short wave. Latest model guidance suggests the associated cold front will surge into western OH/KY by 18z, subsequently advancing into western PA later in the evening. Modest boundary-layer heating should contribute to adequate buoyancy for robust updrafts, and scattered convection should develop ahead of the front as temperatures warm through the 70s. Gusty winds may accompany this activity, along with some risk for marginally severe hail. ...Central Gulf States... Synoptic front will trail across the TN Valley through the central Gulf States today serving as the focus for thunderstorms as convective temperatures are breached along this weakly-forced boundary. While 0-6km bulk shear should only be modest across this region, seasonally high PW values and MLCAPE in excess of 1500 J/kg suggest some risk for gusty winds and hail. Boundary-layer heating should prove instrumental in convective updraft strength today. ..Darrow/Squitieri.. 04/21/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1228 AM CDT Mon Apr 21 2025 Valid 211200Z - 221200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER OHIO VALLEY AND CENTRAL GULF STATES... ...SUMMARY... A few strong storms are possible across the upper Ohio Valley and across portions of the central Gulf States. Gusty winds and marginally severe hail are the primary risks. ...Upper Ohio Valley... Mid-MS Valley short-wave trough is forecast to eject into the upper Great Lakes region by mid day as 70+kt 500mb speed max translates across northern IN into southern ON. 500mb wind fields will strengthen across the upper OH Valley in response to this feature as heights are suppressed ahead of the short wave. Latest model guidance suggests the associated cold front will surge into western OH/KY by 18z, subsequently advancing into western PA later in the evening. Modest boundary-layer heating should contribute to adequate buoyancy for robust updrafts, and scattered convection should develop ahead of the front as temperatures warm through the 70s. Gusty winds may accompany this activity, along with some risk for marginally severe hail. ...Central Gulf States... Synoptic front will trail across the TN Valley through the central Gulf States today serving as the focus for thunderstorms as convective temperatures are breached along this weakly-forced boundary. While 0-6km bulk shear should only be modest across this region, seasonally high PW values and MLCAPE in excess of 1500 J/kg suggest some risk for gusty winds and hail. Boundary-layer heating should prove instrumental in convective updraft strength today. ..Darrow/Squitieri.. 04/21/2025 Read more