Storm Prediction Center

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0718 AM CDT Mon Jul 20 2026 Valid 201300Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE UPPER MIDWEST AND GREAT LAKES... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTH CAROLINA AND FAR SOUTHERN VIRGINIA... ...SUMMARY... Severe thunderstorms are expected across portions of the Upper Midwest and Great Lakes vicinity, especially late this afternoon and tonight. Swaths of damaging winds, large hail, and a few tornadoes will all be possible. Isolated damaging wind gusts may also occur over parts of the Carolinas and southern Virginia. ...Upper Midwest/Great Lakes... Radar/IR satellite composite this morning shows a decaying MCS over far northern IA into west-central WI with warm-advection-related storms moving east-southeast atop the MCS cold pool. This convective activity is occurring downstream of a seasonably potent mid-level shortwave trough and associated jet streak. Surface analysis this morning places a front over the mid MS Valley extending north-northwest and intersecting an outflow boundary over southwest MN. A surface low over western ON is forecast to develop east across north-central ON as an attendant cold front pushes southeast across the Upper Midwest. The front over the mid- to upper MS Valley will advance northeast as a warm front and the warm sector will become increasingly narrow with northward extent in the northern WI vicinity. A warm and seasonably moist airmass will advect northeast into WI in wake of the morning showers/thunderstorms, while a plume of elevated mixed-layer air overspreads the region from the west. Models generally show upper 60s to lower/middle 70s F surface dewpoints contributing to a very unstable boundary layer by mid-late afternoon. However, considerable uncertainty remains regarding details with this forecast update due in part to the morning convection and downstream destabilization/hazard specifics for later this afternoon/evening. It is plausible the initial storms that develop later this afternoon will quickly organize into supercells given strong deep-layer shear and ample buoyancy ahead of the cold front. In agreement with prior forecast thinking, a corridor of large hail and tornado risk will extend from Iowa across Wisconsin into Upper MI. Forecast soundings show elongated hodographs with 35-50 kt 700 mb flow, which will act to enlarge hodographs and perhaps support a couple of strong tornadoes. However, will defer any potential severe changes to later outlook updates if greater confidence and morning convective details are resolved. Eventually, a few clusters will probably evolve this evening, with a continued damaging wind and some tornado risk persisting southeastward before eventually waning overnight. ...Carolinas and southern Virginia... Strong heating to the south of a west-east oriented stalled front will contribute to moderate buoyancy by early to mid afternoon. Rich low-level moisture (surface dewpoints in the 70s F) and moist tropospheric profiles will yield high PW and the potential for water-loaded downdrafts with the more intense thunderstorm cores. Scattered thunderstorms with an isolated to scattered wind-damage threat will probably focus during the 18-00 UTC period. ...Florida... Tropical Depression Two is forecast to slowly intensify across the northeast Gulf of America today and tonight (refer to NHC's latest forecast details). Model guidance shows some gradual strengthening of 2-3km AGL flow, especially across the western Florida Peninsula. Yet, forecast soundings imply the possibility for transient supercell structures will likely be limited/low due to substantially weaker flow in the midlevels---precluding a low-severe highlight at this time. ..Smith/Broyles.. 07/20/2026 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0718 AM CDT Mon Jul 20 2026 Valid 201300Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE UPPER MIDWEST AND GREAT LAKES... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTH CAROLINA AND FAR SOUTHERN VIRGINIA... ...SUMMARY... Severe thunderstorms are expected across portions of the Upper Midwest and Great Lakes vicinity, especially late this afternoon and tonight. Swaths of damaging winds, large hail, and a few tornadoes will all be possible. Isolated damaging wind gusts may also occur over parts of the Carolinas and southern Virginia. ...Upper Midwest/Great Lakes... Radar/IR satellite composite this morning shows a decaying MCS over far northern IA into west-central WI with warm-advection-related storms moving east-southeast atop the MCS cold pool. This convective activity is occurring downstream of a seasonably potent mid-level shortwave trough and associated jet streak. Surface analysis this morning places a front over the mid MS Valley extending north-northwest and intersecting an outflow boundary over southwest MN. A surface low over western ON is forecast to develop east across north-central ON as an attendant cold front pushes southeast across the Upper Midwest. The front over the mid- to upper MS Valley will advance northeast as a warm front and the warm sector will become increasingly narrow with northward extent in the northern WI vicinity. A warm and seasonably moist airmass will advect northeast into WI in wake of the morning showers/thunderstorms, while a plume of elevated mixed-layer air overspreads the region from the west. Models generally show upper 60s to lower/middle 70s F surface dewpoints contributing to a very unstable boundary layer by mid-late afternoon. However, considerable uncertainty remains regarding details with this forecast update due in part to the morning convection and downstream destabilization/hazard specifics for later this afternoon/evening. It is plausible the initial storms that develop later this afternoon will quickly organize into supercells given strong deep-layer shear and ample buoyancy ahead of the cold front. In agreement with prior forecast thinking, a corridor of large hail and tornado risk will extend from Iowa across Wisconsin into Upper MI. Forecast soundings show elongated hodographs with 35-50 kt 700 mb flow, which will act to enlarge hodographs and perhaps support a couple of strong tornadoes. However, will defer any potential severe changes to later outlook updates if greater confidence and morning convective details are resolved. Eventually, a few clusters will probably evolve this evening, with a continued damaging wind and some tornado risk persisting southeastward before eventually waning overnight. ...Carolinas and southern Virginia... Strong heating to the south of a west-east oriented stalled front will contribute to moderate buoyancy by early to mid afternoon. Rich low-level moisture (surface dewpoints in the 70s F) and moist tropospheric profiles will yield high PW and the potential for water-loaded downdrafts with the more intense thunderstorm cores. Scattered thunderstorms with an isolated to scattered wind-damage threat will probably focus during the 18-00 UTC period. ...Florida... Tropical Depression Two is forecast to slowly intensify across the northeast Gulf of America today and tonight (refer to NHC's latest forecast details). Model guidance shows some gradual strengthening of 2-3km AGL flow, especially across the western Florida Peninsula. Yet, forecast soundings imply the possibility for transient supercell structures will likely be limited/low due to substantially weaker flow in the midlevels---precluding a low-severe highlight at this time. ..Smith/Broyles.. 07/20/2026 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0718 AM CDT Mon Jul 20 2026 Valid 201300Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE UPPER MIDWEST AND GREAT LAKES... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTH CAROLINA AND FAR SOUTHERN VIRGINIA... ...SUMMARY... Severe thunderstorms are expected across portions of the Upper Midwest and Great Lakes vicinity, especially late this afternoon and tonight. Swaths of damaging winds, large hail, and a few tornadoes will all be possible. Isolated damaging wind gusts may also occur over parts of the Carolinas and southern Virginia. ...Upper Midwest/Great Lakes... Radar/IR satellite composite this morning shows a decaying MCS over far northern IA into west-central WI with warm-advection-related storms moving east-southeast atop the MCS cold pool. This convective activity is occurring downstream of a seasonably potent mid-level shortwave trough and associated jet streak. Surface analysis this morning places a front over the mid MS Valley extending north-northwest and intersecting an outflow boundary over southwest MN. A surface low over western ON is forecast to develop east across north-central ON as an attendant cold front pushes southeast across the Upper Midwest. The front over the mid- to upper MS Valley will advance northeast as a warm front and the warm sector will become increasingly narrow with northward extent in the northern WI vicinity. A warm and seasonably moist airmass will advect northeast into WI in wake of the morning showers/thunderstorms, while a plume of elevated mixed-layer air overspreads the region from the west. Models generally show upper 60s to lower/middle 70s F surface dewpoints contributing to a very unstable boundary layer by mid-late afternoon. However, considerable uncertainty remains regarding details with this forecast update due in part to the morning convection and downstream destabilization/hazard specifics for later this afternoon/evening. It is plausible the initial storms that develop later this afternoon will quickly organize into supercells given strong deep-layer shear and ample buoyancy ahead of the cold front. In agreement with prior forecast thinking, a corridor of large hail and tornado risk will extend from Iowa across Wisconsin into Upper MI. Forecast soundings show elongated hodographs with 35-50 kt 700 mb flow, which will act to enlarge hodographs and perhaps support a couple of strong tornadoes. However, will defer any potential severe changes to later outlook updates if greater confidence and morning convective details are resolved. Eventually, a few clusters will probably evolve this evening, with a continued damaging wind and some tornado risk persisting southeastward before eventually waning overnight. ...Carolinas and southern Virginia... Strong heating to the south of a west-east oriented stalled front will contribute to moderate buoyancy by early to mid afternoon. Rich low-level moisture (surface dewpoints in the 70s F) and moist tropospheric profiles will yield high PW and the potential for water-loaded downdrafts with the more intense thunderstorm cores. Scattered thunderstorms with an isolated to scattered wind-damage threat will probably focus during the 18-00 UTC period. ...Florida... Tropical Depression Two is forecast to slowly intensify across the northeast Gulf of America today and tonight (refer to NHC's latest forecast details). Model guidance shows some gradual strengthening of 2-3km AGL flow, especially across the western Florida Peninsula. Yet, forecast soundings imply the possibility for transient supercell structures will likely be limited/low due to substantially weaker flow in the midlevels---precluding a low-severe highlight at this time. ..Smith/Broyles.. 07/20/2026 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0718 AM CDT Mon Jul 20 2026 Valid 201300Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE UPPER MIDWEST AND GREAT LAKES... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTH CAROLINA AND FAR SOUTHERN VIRGINIA... ...SUMMARY... Severe thunderstorms are expected across portions of the Upper Midwest and Great Lakes vicinity, especially late this afternoon and tonight. Swaths of damaging winds, large hail, and a few tornadoes will all be possible. Isolated damaging wind gusts may also occur over parts of the Carolinas and southern Virginia. ...Upper Midwest/Great Lakes... Radar/IR satellite composite this morning shows a decaying MCS over far northern IA into west-central WI with warm-advection-related storms moving east-southeast atop the MCS cold pool. This convective activity is occurring downstream of a seasonably potent mid-level shortwave trough and associated jet streak. Surface analysis this morning places a front over the mid MS Valley extending north-northwest and intersecting an outflow boundary over southwest MN. A surface low over western ON is forecast to develop east across north-central ON as an attendant cold front pushes southeast across the Upper Midwest. The front over the mid- to upper MS Valley will advance northeast as a warm front and the warm sector will become increasingly narrow with northward extent in the northern WI vicinity. A warm and seasonably moist airmass will advect northeast into WI in wake of the morning showers/thunderstorms, while a plume of elevated mixed-layer air overspreads the region from the west. Models generally show upper 60s to lower/middle 70s F surface dewpoints contributing to a very unstable boundary layer by mid-late afternoon. However, considerable uncertainty remains regarding details with this forecast update due in part to the morning convection and downstream destabilization/hazard specifics for later this afternoon/evening. It is plausible the initial storms that develop later this afternoon will quickly organize into supercells given strong deep-layer shear and ample buoyancy ahead of the cold front. In agreement with prior forecast thinking, a corridor of large hail and tornado risk will extend from Iowa across Wisconsin into Upper MI. Forecast soundings show elongated hodographs with 35-50 kt 700 mb flow, which will act to enlarge hodographs and perhaps support a couple of strong tornadoes. However, will defer any potential severe changes to later outlook updates if greater confidence and morning convective details are resolved. Eventually, a few clusters will probably evolve this evening, with a continued damaging wind and some tornado risk persisting southeastward before eventually waning overnight. ...Carolinas and southern Virginia... Strong heating to the south of a west-east oriented stalled front will contribute to moderate buoyancy by early to mid afternoon. Rich low-level moisture (surface dewpoints in the 70s F) and moist tropospheric profiles will yield high PW and the potential for water-loaded downdrafts with the more intense thunderstorm cores. Scattered thunderstorms with an isolated to scattered wind-damage threat will probably focus during the 18-00 UTC period. ...Florida... Tropical Depression Two is forecast to slowly intensify across the northeast Gulf of America today and tonight (refer to NHC's latest forecast details). Model guidance shows some gradual strengthening of 2-3km AGL flow, especially across the western Florida Peninsula. Yet, forecast soundings imply the possibility for transient supercell structures will likely be limited/low due to substantially weaker flow in the midlevels---precluding a low-severe highlight at this time. ..Smith/Broyles.. 07/20/2026 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0302 AM CDT Mon Jul 20 2026 Valid 231200Z - 281200Z ...DISCUSSION... Upper troughing will persist across the eastern U.S. through early next week. Meanwhile, a strong, amplified upper ridge will envelop the western half of the CONUS. This should largely limit greater severe potential beneath the upper ridge, though some daily mesoscale-driven strong thunderstorm risk could develop over parts of the Plains as moist southerly low-level flow maintains moisture across the central portions of the country. While any stronger flow aloft will mostly remain north of the international border, some model guidance trends over the last 24 hours indicate strengthening northwesterly flow aloft is possible as a shortwave impulse or two migrates atop the upper ridge and over parts of the northern Plains and Great Lakes. This could support an increasing severe risk across these areas over the weekend, though confidence is too low for any 15 percent probability areas at this time. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0302 AM CDT Mon Jul 20 2026 Valid 231200Z - 281200Z ...DISCUSSION... Upper troughing will persist across the eastern U.S. through early next week. Meanwhile, a strong, amplified upper ridge will envelop the western half of the CONUS. This should largely limit greater severe potential beneath the upper ridge, though some daily mesoscale-driven strong thunderstorm risk could develop over parts of the Plains as moist southerly low-level flow maintains moisture across the central portions of the country. While any stronger flow aloft will mostly remain north of the international border, some model guidance trends over the last 24 hours indicate strengthening northwesterly flow aloft is possible as a shortwave impulse or two migrates atop the upper ridge and over parts of the northern Plains and Great Lakes. This could support an increasing severe risk across these areas over the weekend, though confidence is too low for any 15 percent probability areas at this time. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0302 AM CDT Mon Jul 20 2026 Valid 231200Z - 281200Z ...DISCUSSION... Upper troughing will persist across the eastern U.S. through early next week. Meanwhile, a strong, amplified upper ridge will envelop the western half of the CONUS. This should largely limit greater severe potential beneath the upper ridge, though some daily mesoscale-driven strong thunderstorm risk could develop over parts of the Plains as moist southerly low-level flow maintains moisture across the central portions of the country. While any stronger flow aloft will mostly remain north of the international border, some model guidance trends over the last 24 hours indicate strengthening northwesterly flow aloft is possible as a shortwave impulse or two migrates atop the upper ridge and over parts of the northern Plains and Great Lakes. This could support an increasing severe risk across these areas over the weekend, though confidence is too low for any 15 percent probability areas at this time. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0221 AM CDT Mon Jul 20 2026 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF NORTH CAROLINA INTO SOUTHEAST VIRGINIA... ...SUMMARY... Isolated strong to severe thunderstorms will pose a risk for damaging wind gusts across parts of southeast Virginia and North Carolina. ...Mid-Atlantic to New England... Several shortwave impulses will migrate through persistent upper troughing over the East on Wednesday. At the surface, low pressure will lift northeast across Quebec. A trailing cold front will move east/southeast across portions of the region, become positioned from the Mid-Atlantic coast into central NC by Thursday morning. Southerly low-level flow ahead of the front will maintain a seasonally moist airmass. Moderate destabilization is expected across parts of the Mid-Atlantic into NC where boundary-layer moisture is greater and stronger heating may occur. Weak instability will be located over New England. Around 30-40 kt southwesterly flow from 850-500 mb will provide sufficient vertical shear for some organized cells/clusters. Isolated strong to severe storms producing damaging winds are expected across portions of the Mid-Atlantic into New England, with the greatest risk across parts of VA/NC and vicinity. ..Leitman.. 07/20/2026 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0221 AM CDT Mon Jul 20 2026 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF NORTH CAROLINA INTO SOUTHEAST VIRGINIA... ...SUMMARY... Isolated strong to severe thunderstorms will pose a risk for damaging wind gusts across parts of southeast Virginia and North Carolina. ...Mid-Atlantic to New England... Several shortwave impulses will migrate through persistent upper troughing over the East on Wednesday. At the surface, low pressure will lift northeast across Quebec. A trailing cold front will move east/southeast across portions of the region, become positioned from the Mid-Atlantic coast into central NC by Thursday morning. Southerly low-level flow ahead of the front will maintain a seasonally moist airmass. Moderate destabilization is expected across parts of the Mid-Atlantic into NC where boundary-layer moisture is greater and stronger heating may occur. Weak instability will be located over New England. Around 30-40 kt southwesterly flow from 850-500 mb will provide sufficient vertical shear for some organized cells/clusters. Isolated strong to severe storms producing damaging winds are expected across portions of the Mid-Atlantic into New England, with the greatest risk across parts of VA/NC and vicinity. ..Leitman.. 07/20/2026 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0221 AM CDT Mon Jul 20 2026 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF NORTH CAROLINA INTO SOUTHEAST VIRGINIA... ...SUMMARY... Isolated strong to severe thunderstorms will pose a risk for damaging wind gusts across parts of southeast Virginia and North Carolina. ...Mid-Atlantic to New England... Several shortwave impulses will migrate through persistent upper troughing over the East on Wednesday. At the surface, low pressure will lift northeast across Quebec. A trailing cold front will move east/southeast across portions of the region, become positioned from the Mid-Atlantic coast into central NC by Thursday morning. Southerly low-level flow ahead of the front will maintain a seasonally moist airmass. Moderate destabilization is expected across parts of the Mid-Atlantic into NC where boundary-layer moisture is greater and stronger heating may occur. Weak instability will be located over New England. Around 30-40 kt southwesterly flow from 850-500 mb will provide sufficient vertical shear for some organized cells/clusters. Isolated strong to severe storms producing damaging winds are expected across portions of the Mid-Atlantic into New England, with the greatest risk across parts of VA/NC and vicinity. ..Leitman.. 07/20/2026 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0149 AM CDT Mon Jul 20 2026 Valid 211200Z - 221200Z ...Synopsis... Along the northwestern periphery of a large-scale ridge encompassing much of the central and western CONUS, ample midlevel moisture will be in place atop a warm and dry air mass across parts of northern CA into OR. This will yield inverted-V profiles with weak (albeit sufficient) buoyancy for isolated high-based thunderstorms across the area during the afternoon and evening hours. Given relatively weak large-scale forcing for ascent, the greatest confidence in thunderstorm development is over the Cascades in southern/central OR. While 0.8 to 1.2 inch PW may promote a mix of wet/dry storms, relatively fast storm motions and the dry boundary layer should limit rainfall. As a result, isolated lightning-induced ignitions will be possible. Elsewhere across the CONUS, minimal fire-weather concerns are expected. ..Weinman.. 07/20/2026 ...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 0149 AM CDT Mon Jul 20 2026 Valid 211200Z - 221200Z ...Synopsis... Along the northwestern periphery of a large-scale ridge encompassing much of the central and western CONUS, ample midlevel moisture will be in place atop a warm and dry air mass across parts of northern CA into OR. This will yield inverted-V profiles with weak (albeit sufficient) buoyancy for isolated high-based thunderstorms across the area during the afternoon and evening hours. Given relatively weak large-scale forcing for ascent, the greatest confidence in thunderstorm development is over the Cascades in southern/central OR. While 0.8 to 1.2 inch PW may promote a mix of wet/dry storms, relatively fast storm motions and the dry boundary layer should limit rainfall. As a result, isolated lightning-induced ignitions will be possible. Elsewhere across the CONUS, minimal fire-weather concerns are expected. ..Weinman.. 07/20/2026 ...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 0149 AM CDT Mon Jul 20 2026 Valid 211200Z - 221200Z ...Synopsis... Along the northwestern periphery of a large-scale ridge encompassing much of the central and western CONUS, ample midlevel moisture will be in place atop a warm and dry air mass across parts of northern CA into OR. This will yield inverted-V profiles with weak (albeit sufficient) buoyancy for isolated high-based thunderstorms across the area during the afternoon and evening hours. Given relatively weak large-scale forcing for ascent, the greatest confidence in thunderstorm development is over the Cascades in southern/central OR. While 0.8 to 1.2 inch PW may promote a mix of wet/dry storms, relatively fast storm motions and the dry boundary layer should limit rainfall. As a result, isolated lightning-induced ignitions will be possible. Elsewhere across the CONUS, minimal fire-weather concerns are expected. ..Weinman.. 07/20/2026 ...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 0148 AM CDT Mon Jul 20 2026 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... ...Synopsis... Along the northwestern periphery of an expansive upper ridge over the West, a low-amplitude midlevel disturbance and accompanying influx of midlevel moisture will overspread parts of the Northwest today. While this should support isolated high-based showers, weak buoyancy and warm EL temperatures should limit thunderstorm potential. With that said, an isolated storm or two cannot be entirely ruled out over the Cascades in OR. Elsewhere, a limited overlap of dry/windy conditions atop receptive fuels will reduce fire-weather concerns across the CONUS. ..Weinman.. 07/20/2026 ...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 0148 AM CDT Mon Jul 20 2026 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... ...Synopsis... Along the northwestern periphery of an expansive upper ridge over the West, a low-amplitude midlevel disturbance and accompanying influx of midlevel moisture will overspread parts of the Northwest today. While this should support isolated high-based showers, weak buoyancy and warm EL temperatures should limit thunderstorm potential. With that said, an isolated storm or two cannot be entirely ruled out over the Cascades in OR. Elsewhere, a limited overlap of dry/windy conditions atop receptive fuels will reduce fire-weather concerns across the CONUS. ..Weinman.. 07/20/2026 ...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 0148 AM CDT Mon Jul 20 2026 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... ...Synopsis... Along the northwestern periphery of an expansive upper ridge over the West, a low-amplitude midlevel disturbance and accompanying influx of midlevel moisture will overspread parts of the Northwest today. While this should support isolated high-based showers, weak buoyancy and warm EL temperatures should limit thunderstorm potential. With that said, an isolated storm or two cannot be entirely ruled out over the Cascades in OR. Elsewhere, a limited overlap of dry/windy conditions atop receptive fuels will reduce fire-weather concerns across the CONUS. ..Weinman.. 07/20/2026 ...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 1239 AM CDT Mon Jul 20 2026 Valid 211200Z - 221200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHERN INDIANA...NORTHEAST KENTUCKY...SOUTHERN/EASTERN OHIO...WEST VIRGINIA...NORTHERN VIRGINIA...MARYLAND...AND PENNSYLVANIA... ...SUMMARY... Numerous severe thunderstorms are expected across a broad region from the Ohio Valley into the Mid-Atlantic and Northeast on Tuesday. All severe hazards are possible, but swaths of damaging wind gusts should be the primary severe risk Tuesday afternoon into the nighttime hours. ...Ohio Valley to the Mid-Atlantic and Northeast... An upper trough will be oriented over the region on Tuesday, with several shortwave impulses migrating through the larger-scale system. At the surface, low pressure will move across southern Ontario into Quebec. A trailing cold front will move across much of the Midwest through the period, becoming positioned from western PA to TN and northern AR/OK by Wednesday morning. Ahead of the main surface front, surface prefrontal troughing is expected to develop across western/central NY into the Mid-Atlantic vicinity. Rich boundary-layer moisture will overspread much of the area, with dewpoints from the mid-60s to low 70s F commonplace. This will aid in development of moderate to strong instability. Deep-layer flow will be strong for this time of year, with 40-60 kt flow at 500 mb, and 30-50 kt in the 850-700 mb layer. Forecast soundings indicate supercell wind profiles with favorably curved low-level hodographs becoming elongated above 2-3 km across much of the region. Convective evolution remains a bit uncertain, but a mix of supercells and one or more bowing linear segments are expected across the Ohio Valley into the Mid-Atlantic. Significant severe (2+ inch hail, 65+ kt winds, etc) potential is unclear, and will largely depend on storm mode and mesoscale evolution of convection. Temperatures aloft are relatively warm, around -5 to -7 C at 500 mb, and this may inhibit sig hail potential. Meanwhile, 65+ kt gusts could occur if a well-organized bowing structure and stronger cold pool can develop. Given warm/moist low-levels and limited low-level lapse rates, confidence in this scenario is low. As a result, the CIG 1 area from the prior Day 3 outlook has been removed for now. Where supercells can be maintained, a risk for a few tornadoes also is possible. While details regarding storm mode and evolution remain somewhat uncertain, the overall environment will support a severe risk across a broad region on Tuesday/Tuesday evening. Swaths of damaging winds still appear to be the greatest risk, though all hazards are possible. ..Leitman.. 07/20/2026 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1239 AM CDT Mon Jul 20 2026 Valid 211200Z - 221200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHERN INDIANA...NORTHEAST KENTUCKY...SOUTHERN/EASTERN OHIO...WEST VIRGINIA...NORTHERN VIRGINIA...MARYLAND...AND PENNSYLVANIA... ...SUMMARY... Numerous severe thunderstorms are expected across a broad region from the Ohio Valley into the Mid-Atlantic and Northeast on Tuesday. All severe hazards are possible, but swaths of damaging wind gusts should be the primary severe risk Tuesday afternoon into the nighttime hours. ...Ohio Valley to the Mid-Atlantic and Northeast... An upper trough will be oriented over the region on Tuesday, with several shortwave impulses migrating through the larger-scale system. At the surface, low pressure will move across southern Ontario into Quebec. A trailing cold front will move across much of the Midwest through the period, becoming positioned from western PA to TN and northern AR/OK by Wednesday morning. Ahead of the main surface front, surface prefrontal troughing is expected to develop across western/central NY into the Mid-Atlantic vicinity. Rich boundary-layer moisture will overspread much of the area, with dewpoints from the mid-60s to low 70s F commonplace. This will aid in development of moderate to strong instability. Deep-layer flow will be strong for this time of year, with 40-60 kt flow at 500 mb, and 30-50 kt in the 850-700 mb layer. Forecast soundings indicate supercell wind profiles with favorably curved low-level hodographs becoming elongated above 2-3 km across much of the region. Convective evolution remains a bit uncertain, but a mix of supercells and one or more bowing linear segments are expected across the Ohio Valley into the Mid-Atlantic. Significant severe (2+ inch hail, 65+ kt winds, etc) potential is unclear, and will largely depend on storm mode and mesoscale evolution of convection. Temperatures aloft are relatively warm, around -5 to -7 C at 500 mb, and this may inhibit sig hail potential. Meanwhile, 65+ kt gusts could occur if a well-organized bowing structure and stronger cold pool can develop. Given warm/moist low-levels and limited low-level lapse rates, confidence in this scenario is low. As a result, the CIG 1 area from the prior Day 3 outlook has been removed for now. Where supercells can be maintained, a risk for a few tornadoes also is possible. While details regarding storm mode and evolution remain somewhat uncertain, the overall environment will support a severe risk across a broad region on Tuesday/Tuesday evening. Swaths of damaging winds still appear to be the greatest risk, though all hazards are possible. ..Leitman.. 07/20/2026 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0102 AM CDT Mon Jul 20 2026 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE UPPER MIDWEST AND GREAT LAKES... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTH CAROLINA AND FAR SOUTHERN VIRGINIA... ...SUMMARY... Severe thunderstorms are expected across portions of the Upper Midwest and Great Lakes vicinity, especially late this afternoon and tonight. Swaths of damaging winds, large hail, and a few tornadoes will all be possible. Isolated damaging wind gusts may also occur over parts of the Carolinas and southern Virginia. ...Upper Midwest/Great Lakes... A potentially active severe-weather scenario is expected later today into tonight, although some key uncertainties persist related to the potential impacts of early day convection and associated cloud debris. A substantial shortwave trough over southern Manitoba will continue to gradually amplify and spread southeastward to the Lake Superior vicinity through tonight, with a strengthening belt of mid/high-level west-northwesterly flow overspreading the Upper Midwest toward the Lake Michigan vicinity, highlighted by 50-70 kt mid-level winds and 100 kt winds in the upper levels across Minnesota/Wisconsin. An east/southeastward-advecting plume of steep mid-level lapse rates will overspread a warm sector with upper 60s to lower/middle 70s F dewpoints. Initially, a few early day storms could produce hail and perhaps some strong wind gusts across east/southeast Minnesota into western Wisconsin and eastern Iowa, amidst ample elevated instability and effective shear over 50 kt. This activity may continue to spread southeastward this morning but tend to wane during the day, leading to a potential regional break prior to additional/more vigorous development by late afternoon along the cold front as it progresses east-southeastward toward Wisconsin/Upper Michigan and northern/eastern Iowa. The initial storms should primarily be supercells given such strong deep-layer shear. A corridor of large hail and tornado risk is evident east of the instability axis from Iowa across Wisconsin into Upper MI. Even while near-surface winds may tend to veer with time, effective SRH may exceed 300 m2/s2, especially across Wisconsin toward Upper Michigan as supported by the seasonally very-strong 2-3 km AGL winds (700 mb winds in excess of 50 kt). The degree of SRH could support a couple strong tornadoes (EF2+), and somewhat higher tornado probabilities could be warranted in subsequent outlooks as early day convection details are resolved. While supercells will persist for a time, several storm clusters will evolve this evening, with a continued damaging wind and some tornado risk persisting southeastward this evening prior to storm intensity eventually waning overnight. ...Carolinas and southern Virginia... Convection and related cloud debris may persist early today, but a moist air mass will again diurnally destabilize this afternoon along and south of a roughly west/east-oriented front. Daytime heating, 70s F dewpoints and surface convergence will aid storm formation and intensification this afternoon. MLCAPE in excess of 2000 J/kg, PWAT over 2.00", and mid-level westerly flow aloft of 15-20 kt will lead to multicellular storm mode with isolated damaging wind gusts during the afternoon until around sunset. ...Florida... Tropical Depression Two may gradually strengthen across the northeast Gulf of America today and tonight. Reference the National Hurricane Center for the latest development/forecast details. While various global models support the notion of a strengthening of southerly winds in the lowest 2-3km AGL, especially across the western Florida Peninsula, it currently appears that supercell-related tornado potential should remain low, largely attributable to the overall weakness of the Depression and weak wind aloft. ..Guyer/Weinman.. 07/20/2026 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0102 AM CDT Mon Jul 20 2026 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE UPPER MIDWEST AND GREAT LAKES... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS NORTH CAROLINA AND FAR SOUTHERN VIRGINIA... ...SUMMARY... Severe thunderstorms are expected across portions of the Upper Midwest and Great Lakes vicinity, especially late this afternoon and tonight. Swaths of damaging winds, large hail, and a few tornadoes will all be possible. Isolated damaging wind gusts may also occur over parts of the Carolinas and southern Virginia. ...Upper Midwest/Great Lakes... A potentially active severe-weather scenario is expected later today into tonight, although some key uncertainties persist related to the potential impacts of early day convection and associated cloud debris. A substantial shortwave trough over southern Manitoba will continue to gradually amplify and spread southeastward to the Lake Superior vicinity through tonight, with a strengthening belt of mid/high-level west-northwesterly flow overspreading the Upper Midwest toward the Lake Michigan vicinity, highlighted by 50-70 kt mid-level winds and 100 kt winds in the upper levels across Minnesota/Wisconsin. An east/southeastward-advecting plume of steep mid-level lapse rates will overspread a warm sector with upper 60s to lower/middle 70s F dewpoints. Initially, a few early day storms could produce hail and perhaps some strong wind gusts across east/southeast Minnesota into western Wisconsin and eastern Iowa, amidst ample elevated instability and effective shear over 50 kt. This activity may continue to spread southeastward this morning but tend to wane during the day, leading to a potential regional break prior to additional/more vigorous development by late afternoon along the cold front as it progresses east-southeastward toward Wisconsin/Upper Michigan and northern/eastern Iowa. The initial storms should primarily be supercells given such strong deep-layer shear. A corridor of large hail and tornado risk is evident east of the instability axis from Iowa across Wisconsin into Upper MI. Even while near-surface winds may tend to veer with time, effective SRH may exceed 300 m2/s2, especially across Wisconsin toward Upper Michigan as supported by the seasonally very-strong 2-3 km AGL winds (700 mb winds in excess of 50 kt). The degree of SRH could support a couple strong tornadoes (EF2+), and somewhat higher tornado probabilities could be warranted in subsequent outlooks as early day convection details are resolved. While supercells will persist for a time, several storm clusters will evolve this evening, with a continued damaging wind and some tornado risk persisting southeastward this evening prior to storm intensity eventually waning overnight. ...Carolinas and southern Virginia... Convection and related cloud debris may persist early today, but a moist air mass will again diurnally destabilize this afternoon along and south of a roughly west/east-oriented front. Daytime heating, 70s F dewpoints and surface convergence will aid storm formation and intensification this afternoon. MLCAPE in excess of 2000 J/kg, PWAT over 2.00", and mid-level westerly flow aloft of 15-20 kt will lead to multicellular storm mode with isolated damaging wind gusts during the afternoon until around sunset. ...Florida... Tropical Depression Two may gradually strengthen across the northeast Gulf of America today and tonight. Reference the National Hurricane Center for the latest development/forecast details. While various global models support the notion of a strengthening of southerly winds in the lowest 2-3km AGL, especially across the western Florida Peninsula, it currently appears that supercell-related tornado potential should remain low, largely attributable to the overall weakness of the Depression and weak wind aloft. ..Guyer/Weinman.. 07/20/2026 Read more