Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0134 PM CST Sun Dec 03 2023 Valid 032000Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF WESTERN PENNSYLVANIA AND VICINITY... ...SUMMARY... Isolated, marginally severe thunderstorms are possible over western Pennsylvania and vicinity this afternoon. ...20Z Update... Low-topped convection is increasing this afternoon from eastern OH into western PA, in advance of a dynamic mid/upper-level shortwave trough approaching the upper OH Valley. Uncertainty remains regarding the potential for stronger storms to mature within the favorably sheared but weakly unstable environment, but some potential remains for gusty/locally damaging winds, hail of 0.5-1 inch in diameter, and possibly a brief tornado. See the previous outlook discussion below for more information, and MCD 2302 regarding the short-term threat across western PA and vicinity. ..Dean.. 12/03/2023 .PREV DISCUSSION... /ISSUED 1018 AM CST Sun Dec 03 2023/ ...Upper OH Valley... Morning water vapor imagery shows a fast-moving intense shortwave trough over central IL. This feature will become negatively tilted this afternoon as it races eastward into parts of OH/PA/NY. A strong mid/upper level jet is associated with this system, with 90+ knot winds at 500mb and 150+ knots at 300mb providing significant mesoscale forcing in the left-front quad of the jet as it tracks into western PA around peak heating. Most 12z models show the development of scattered fast-moving showers and isolated thunderstorms later today (mainly 20-01z), but luckily thermodynamics are expected to be quite weak (CAPE values generally 200-500 J/kg and dewpoints only around 50F). The combination of very steep mid-level lapse rates, ambient vorticity, and strong lift could result in funnel clouds or a brief tornado from this convection, along with small hail and gusty winds. However, the overall severe threat appears marginal due to the weak instability. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0134 PM CST Sun Dec 03 2023 Valid 032000Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF WESTERN PENNSYLVANIA AND VICINITY... ...SUMMARY... Isolated, marginally severe thunderstorms are possible over western Pennsylvania and vicinity this afternoon. ...20Z Update... Low-topped convection is increasing this afternoon from eastern OH into western PA, in advance of a dynamic mid/upper-level shortwave trough approaching the upper OH Valley. Uncertainty remains regarding the potential for stronger storms to mature within the favorably sheared but weakly unstable environment, but some potential remains for gusty/locally damaging winds, hail of 0.5-1 inch in diameter, and possibly a brief tornado. See the previous outlook discussion below for more information, and MCD 2302 regarding the short-term threat across western PA and vicinity. ..Dean.. 12/03/2023 .PREV DISCUSSION... /ISSUED 1018 AM CST Sun Dec 03 2023/ ...Upper OH Valley... Morning water vapor imagery shows a fast-moving intense shortwave trough over central IL. This feature will become negatively tilted this afternoon as it races eastward into parts of OH/PA/NY. A strong mid/upper level jet is associated with this system, with 90+ knot winds at 500mb and 150+ knots at 300mb providing significant mesoscale forcing in the left-front quad of the jet as it tracks into western PA around peak heating. Most 12z models show the development of scattered fast-moving showers and isolated thunderstorms later today (mainly 20-01z), but luckily thermodynamics are expected to be quite weak (CAPE values generally 200-500 J/kg and dewpoints only around 50F). The combination of very steep mid-level lapse rates, ambient vorticity, and strong lift could result in funnel clouds or a brief tornado from this convection, along with small hail and gusty winds. However, the overall severe threat appears marginal due to the weak instability. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0134 PM CST Sun Dec 03 2023 Valid 032000Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF WESTERN PENNSYLVANIA AND VICINITY... ...SUMMARY... Isolated, marginally severe thunderstorms are possible over western Pennsylvania and vicinity this afternoon. ...20Z Update... Low-topped convection is increasing this afternoon from eastern OH into western PA, in advance of a dynamic mid/upper-level shortwave trough approaching the upper OH Valley. Uncertainty remains regarding the potential for stronger storms to mature within the favorably sheared but weakly unstable environment, but some potential remains for gusty/locally damaging winds, hail of 0.5-1 inch in diameter, and possibly a brief tornado. See the previous outlook discussion below for more information, and MCD 2302 regarding the short-term threat across western PA and vicinity. ..Dean.. 12/03/2023 .PREV DISCUSSION... /ISSUED 1018 AM CST Sun Dec 03 2023/ ...Upper OH Valley... Morning water vapor imagery shows a fast-moving intense shortwave trough over central IL. This feature will become negatively tilted this afternoon as it races eastward into parts of OH/PA/NY. A strong mid/upper level jet is associated with this system, with 90+ knot winds at 500mb and 150+ knots at 300mb providing significant mesoscale forcing in the left-front quad of the jet as it tracks into western PA around peak heating. Most 12z models show the development of scattered fast-moving showers and isolated thunderstorms later today (mainly 20-01z), but luckily thermodynamics are expected to be quite weak (CAPE values generally 200-500 J/kg and dewpoints only around 50F). The combination of very steep mid-level lapse rates, ambient vorticity, and strong lift could result in funnel clouds or a brief tornado from this convection, along with small hail and gusty winds. However, the overall severe threat appears marginal due to the weak instability. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0134 PM CST Sun Dec 03 2023 Valid 032000Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF WESTERN PENNSYLVANIA AND VICINITY... ...SUMMARY... Isolated, marginally severe thunderstorms are possible over western Pennsylvania and vicinity this afternoon. ...20Z Update... Low-topped convection is increasing this afternoon from eastern OH into western PA, in advance of a dynamic mid/upper-level shortwave trough approaching the upper OH Valley. Uncertainty remains regarding the potential for stronger storms to mature within the favorably sheared but weakly unstable environment, but some potential remains for gusty/locally damaging winds, hail of 0.5-1 inch in diameter, and possibly a brief tornado. See the previous outlook discussion below for more information, and MCD 2302 regarding the short-term threat across western PA and vicinity. ..Dean.. 12/03/2023 .PREV DISCUSSION... /ISSUED 1018 AM CST Sun Dec 03 2023/ ...Upper OH Valley... Morning water vapor imagery shows a fast-moving intense shortwave trough over central IL. This feature will become negatively tilted this afternoon as it races eastward into parts of OH/PA/NY. A strong mid/upper level jet is associated with this system, with 90+ knot winds at 500mb and 150+ knots at 300mb providing significant mesoscale forcing in the left-front quad of the jet as it tracks into western PA around peak heating. Most 12z models show the development of scattered fast-moving showers and isolated thunderstorms later today (mainly 20-01z), but luckily thermodynamics are expected to be quite weak (CAPE values generally 200-500 J/kg and dewpoints only around 50F). The combination of very steep mid-level lapse rates, ambient vorticity, and strong lift could result in funnel clouds or a brief tornado from this convection, along with small hail and gusty winds. However, the overall severe threat appears marginal due to the weak instability. Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1049 AM CST Sun Dec 03 2023 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Synopsis... An upper-level trough will cover much of the central/eastern CONUS on Monday. One embedded shortwave trough will move quickly from the lower OH Valley toward the Mid Atlantic during the day, while an upstream shortwave digs southeastward from the northern Great Plains toward the mid MS Valley. Generally dry and stable conditions will cover most of the CONUS, resulting in limited thunderstorm potential. Weak destabilization and ascent attendant to the shortwave initially over the OH Valley may support sporadic lightning flashes with low-topped convection from southern IN through KY into western VA. Otherwise, while weak convection may affect coastal regions of the Pacific Northwest and also parts of central/south FL, thunderstorm probabilities appear low across these areas at this time. ..Dean.. 12/03/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1049 AM CST Sun Dec 03 2023 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Synopsis... An upper-level trough will cover much of the central/eastern CONUS on Monday. One embedded shortwave trough will move quickly from the lower OH Valley toward the Mid Atlantic during the day, while an upstream shortwave digs southeastward from the northern Great Plains toward the mid MS Valley. Generally dry and stable conditions will cover most of the CONUS, resulting in limited thunderstorm potential. Weak destabilization and ascent attendant to the shortwave initially over the OH Valley may support sporadic lightning flashes with low-topped convection from southern IN through KY into western VA. Otherwise, while weak convection may affect coastal regions of the Pacific Northwest and also parts of central/south FL, thunderstorm probabilities appear low across these areas at this time. ..Dean.. 12/03/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1049 AM CST Sun Dec 03 2023 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Synopsis... An upper-level trough will cover much of the central/eastern CONUS on Monday. One embedded shortwave trough will move quickly from the lower OH Valley toward the Mid Atlantic during the day, while an upstream shortwave digs southeastward from the northern Great Plains toward the mid MS Valley. Generally dry and stable conditions will cover most of the CONUS, resulting in limited thunderstorm potential. Weak destabilization and ascent attendant to the shortwave initially over the OH Valley may support sporadic lightning flashes with low-topped convection from southern IN through KY into western VA. Otherwise, while weak convection may affect coastal regions of the Pacific Northwest and also parts of central/south FL, thunderstorm probabilities appear low across these areas at this time. ..Dean.. 12/03/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1049 AM CST Sun Dec 03 2023 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Synopsis... An upper-level trough will cover much of the central/eastern CONUS on Monday. One embedded shortwave trough will move quickly from the lower OH Valley toward the Mid Atlantic during the day, while an upstream shortwave digs southeastward from the northern Great Plains toward the mid MS Valley. Generally dry and stable conditions will cover most of the CONUS, resulting in limited thunderstorm potential. Weak destabilization and ascent attendant to the shortwave initially over the OH Valley may support sporadic lightning flashes with low-topped convection from southern IN through KY into western VA. Otherwise, while weak convection may affect coastal regions of the Pacific Northwest and also parts of central/south FL, thunderstorm probabilities appear low across these areas at this time. ..Dean.. 12/03/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1049 AM CST Sun Dec 03 2023 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Synopsis... An upper-level trough will cover much of the central/eastern CONUS on Monday. One embedded shortwave trough will move quickly from the lower OH Valley toward the Mid Atlantic during the day, while an upstream shortwave digs southeastward from the northern Great Plains toward the mid MS Valley. Generally dry and stable conditions will cover most of the CONUS, resulting in limited thunderstorm potential. Weak destabilization and ascent attendant to the shortwave initially over the OH Valley may support sporadic lightning flashes with low-topped convection from southern IN through KY into western VA. Otherwise, while weak convection may affect coastal regions of the Pacific Northwest and also parts of central/south FL, thunderstorm probabilities appear low across these areas at this time. ..Dean.. 12/03/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1049 AM CST Sun Dec 03 2023 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Synopsis... An upper-level trough will cover much of the central/eastern CONUS on Monday. One embedded shortwave trough will move quickly from the lower OH Valley toward the Mid Atlantic during the day, while an upstream shortwave digs southeastward from the northern Great Plains toward the mid MS Valley. Generally dry and stable conditions will cover most of the CONUS, resulting in limited thunderstorm potential. Weak destabilization and ascent attendant to the shortwave initially over the OH Valley may support sporadic lightning flashes with low-topped convection from southern IN through KY into western VA. Otherwise, while weak convection may affect coastal regions of the Pacific Northwest and also parts of central/south FL, thunderstorm probabilities appear low across these areas at this time. ..Dean.. 12/03/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1049 AM CST Sun Dec 03 2023 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Monday. ...Synopsis... An upper-level trough will cover much of the central/eastern CONUS on Monday. One embedded shortwave trough will move quickly from the lower OH Valley toward the Mid Atlantic during the day, while an upstream shortwave digs southeastward from the northern Great Plains toward the mid MS Valley. Generally dry and stable conditions will cover most of the CONUS, resulting in limited thunderstorm potential. Weak destabilization and ascent attendant to the shortwave initially over the OH Valley may support sporadic lightning flashes with low-topped convection from southern IN through KY into western VA. Otherwise, while weak convection may affect coastal regions of the Pacific Northwest and also parts of central/south FL, thunderstorm probabilities appear low across these areas at this time. ..Dean.. 12/03/2023 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1048 AM CST Sun Dec 03 2023 Valid 031700Z - 041200Z ...NO CRITICAL AREAS... No changes. See previous discussion below. ..Bentley.. 12/03/2023 .PREV DISCUSSION... /ISSUED 1226 AM CST Sun Dec 03 2023/ ...Synopsis... Enhanced west to northwesterly upper-level flow across the Rockies into the High Plains will support dry downslope flow in to the Central High and Southern Plains this afternoon. Relative humidity reductions to around 15-20 percent with sustained winds around 20-25 mph will overlap across the Texas/Oklahoma Panhandles into far western Texas. While fuels in these regions remain above seasonal average for moistness, some drying can be expected in dormant fine fuels. Given low confidence in status of fuels, no areas have been included with this outlook, though Elevated meteorological conditions are possible. ...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 1048 AM CST Sun Dec 03 2023 Valid 031700Z - 041200Z ...NO CRITICAL AREAS... No changes. See previous discussion below. ..Bentley.. 12/03/2023 .PREV DISCUSSION... /ISSUED 1226 AM CST Sun Dec 03 2023/ ...Synopsis... Enhanced west to northwesterly upper-level flow across the Rockies into the High Plains will support dry downslope flow in to the Central High and Southern Plains this afternoon. Relative humidity reductions to around 15-20 percent with sustained winds around 20-25 mph will overlap across the Texas/Oklahoma Panhandles into far western Texas. While fuels in these regions remain above seasonal average for moistness, some drying can be expected in dormant fine fuels. Given low confidence in status of fuels, no areas have been included with this outlook, though Elevated meteorological conditions are possible. ...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 1048 AM CST Sun Dec 03 2023 Valid 031700Z - 041200Z ...NO CRITICAL AREAS... No changes. See previous discussion below. ..Bentley.. 12/03/2023 .PREV DISCUSSION... /ISSUED 1226 AM CST Sun Dec 03 2023/ ...Synopsis... Enhanced west to northwesterly upper-level flow across the Rockies into the High Plains will support dry downslope flow in to the Central High and Southern Plains this afternoon. Relative humidity reductions to around 15-20 percent with sustained winds around 20-25 mph will overlap across the Texas/Oklahoma Panhandles into far western Texas. While fuels in these regions remain above seasonal average for moistness, some drying can be expected in dormant fine fuels. Given low confidence in status of fuels, no areas have been included with this outlook, though Elevated meteorological conditions are possible. ...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 1048 AM CST Sun Dec 03 2023 Valid 031700Z - 041200Z ...NO CRITICAL AREAS... No changes. See previous discussion below. ..Bentley.. 12/03/2023 .PREV DISCUSSION... /ISSUED 1226 AM CST Sun Dec 03 2023/ ...Synopsis... Enhanced west to northwesterly upper-level flow across the Rockies into the High Plains will support dry downslope flow in to the Central High and Southern Plains this afternoon. Relative humidity reductions to around 15-20 percent with sustained winds around 20-25 mph will overlap across the Texas/Oklahoma Panhandles into far western Texas. While fuels in these regions remain above seasonal average for moistness, some drying can be expected in dormant fine fuels. Given low confidence in status of fuels, no areas have been included with this outlook, though Elevated meteorological conditions are possible. ...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 1048 AM CST Sun Dec 03 2023 Valid 031700Z - 041200Z ...NO CRITICAL AREAS... No changes. See previous discussion below. ..Bentley.. 12/03/2023 .PREV DISCUSSION... /ISSUED 1226 AM CST Sun Dec 03 2023/ ...Synopsis... Enhanced west to northwesterly upper-level flow across the Rockies into the High Plains will support dry downslope flow in to the Central High and Southern Plains this afternoon. Relative humidity reductions to around 15-20 percent with sustained winds around 20-25 mph will overlap across the Texas/Oklahoma Panhandles into far western Texas. While fuels in these regions remain above seasonal average for moistness, some drying can be expected in dormant fine fuels. Given low confidence in status of fuels, no areas have been included with this outlook, though Elevated meteorological conditions are possible. ...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 1048 AM CST Sun Dec 03 2023 Valid 031700Z - 041200Z ...NO CRITICAL AREAS... No changes. See previous discussion below. ..Bentley.. 12/03/2023 .PREV DISCUSSION... /ISSUED 1226 AM CST Sun Dec 03 2023/ ...Synopsis... Enhanced west to northwesterly upper-level flow across the Rockies into the High Plains will support dry downslope flow in to the Central High and Southern Plains this afternoon. Relative humidity reductions to around 15-20 percent with sustained winds around 20-25 mph will overlap across the Texas/Oklahoma Panhandles into far western Texas. While fuels in these regions remain above seasonal average for moistness, some drying can be expected in dormant fine fuels. Given low confidence in status of fuels, no areas have been included with this outlook, though Elevated meteorological conditions are possible. ...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 1048 AM CST Sun Dec 03 2023 Valid 031700Z - 041200Z ...NO CRITICAL AREAS... No changes. See previous discussion below. ..Bentley.. 12/03/2023 .PREV DISCUSSION... /ISSUED 1226 AM CST Sun Dec 03 2023/ ...Synopsis... Enhanced west to northwesterly upper-level flow across the Rockies into the High Plains will support dry downslope flow in to the Central High and Southern Plains this afternoon. Relative humidity reductions to around 15-20 percent with sustained winds around 20-25 mph will overlap across the Texas/Oklahoma Panhandles into far western Texas. While fuels in these regions remain above seasonal average for moistness, some drying can be expected in dormant fine fuels. Given low confidence in status of fuels, no areas have been included with this outlook, though Elevated meteorological conditions are possible. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1018 AM CST Sun Dec 03 2023 Valid 031630Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PORTIONS OF WESTERN PENNSYLVANIA AND VICINITY... ...SUMMARY... Isolated, marginally severe thunderstorms are possible over western Pennsylvania and vicinity this afternoon. ...Upper OH Valley... Morning water vapor imagery shows a fast-moving intense shortwave trough over central IL. This feature will become negatively tilted this afternoon as it races eastward into parts of OH/PA/NY. A strong mid/upper level jet is associated with this system, with 90+ knot winds at 500mb and 150+ knots at 300mb providing significant mesoscale forcing in the left-front quad of the jet as it tracks into western PA around peak heating. Most 12z models show the development of scattered fast-moving showers and isolated thunderstorms later today (mainly 20-01z), but luckily thermodynamics are expected to be quite weak (CAPE values generally 200-500 J/kg and dewpoints only around 50F). The combination of very steep mid-level lapse rates, ambient vorticity, and strong lift could result in funnel clouds or a brief tornado from this convection, along with small hail and gusty winds. However, the overall severe threat appears marginal due to the weak instability. ..Hart/Lyons.. 12/03/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1018 AM CST Sun Dec 03 2023 Valid 031630Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PORTIONS OF WESTERN PENNSYLVANIA AND VICINITY... ...SUMMARY... Isolated, marginally severe thunderstorms are possible over western Pennsylvania and vicinity this afternoon. ...Upper OH Valley... Morning water vapor imagery shows a fast-moving intense shortwave trough over central IL. This feature will become negatively tilted this afternoon as it races eastward into parts of OH/PA/NY. A strong mid/upper level jet is associated with this system, with 90+ knot winds at 500mb and 150+ knots at 300mb providing significant mesoscale forcing in the left-front quad of the jet as it tracks into western PA around peak heating. Most 12z models show the development of scattered fast-moving showers and isolated thunderstorms later today (mainly 20-01z), but luckily thermodynamics are expected to be quite weak (CAPE values generally 200-500 J/kg and dewpoints only around 50F). The combination of very steep mid-level lapse rates, ambient vorticity, and strong lift could result in funnel clouds or a brief tornado from this convection, along with small hail and gusty winds. However, the overall severe threat appears marginal due to the weak instability. ..Hart/Lyons.. 12/03/2023 Read more