Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0155 PM CST Sun Dec 03 2023 Valid 041200Z - 051200Z ...NO CRITICAL AREAS... No changes. See previous discussion below. ..Bentley.. 12/03/2023 .PREV DISCUSSION... /ISSUED 1228 AM CST Sun Dec 03 2023/ ...Synopsis... High pressure will build in across the western US on Monday, with a dry cold frontal passage bringing cooler temperatures across much of the Plains. Weakening westerly gradients will give way to lighter southerly winds, with higher afternoon relative humidity across the central and southern Plains. As such, fire weather concerns will remain low on Monday. ...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 0155 PM CST Sun Dec 03 2023 Valid 041200Z - 051200Z ...NO CRITICAL AREAS... No changes. See previous discussion below. ..Bentley.. 12/03/2023 .PREV DISCUSSION... /ISSUED 1228 AM CST Sun Dec 03 2023/ ...Synopsis... High pressure will build in across the western US on Monday, with a dry cold frontal passage bringing cooler temperatures across much of the Plains. Weakening westerly gradients will give way to lighter southerly winds, with higher afternoon relative humidity across the central and southern Plains. As such, fire weather concerns will remain low on Monday. ...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 0155 PM CST Sun Dec 03 2023 Valid 041200Z - 051200Z ...NO CRITICAL AREAS... No changes. See previous discussion below. ..Bentley.. 12/03/2023 .PREV DISCUSSION... /ISSUED 1228 AM CST Sun Dec 03 2023/ ...Synopsis... High pressure will build in across the western US on Monday, with a dry cold frontal passage bringing cooler temperatures across much of the Plains. Weakening westerly gradients will give way to lighter southerly winds, with higher afternoon relative humidity across the central and southern Plains. As such, fire weather concerns will remain low on Monday. ...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 0155 PM CST Sun Dec 03 2023 Valid 041200Z - 051200Z ...NO CRITICAL AREAS... No changes. See previous discussion below. ..Bentley.. 12/03/2023 .PREV DISCUSSION... /ISSUED 1228 AM CST Sun Dec 03 2023/ ...Synopsis... High pressure will build in across the western US on Monday, with a dry cold frontal passage bringing cooler temperatures across much of the Plains. Weakening westerly gradients will give way to lighter southerly winds, with higher afternoon relative humidity across the central and southern Plains. As such, fire weather concerns will remain low on Monday. ...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 0155 PM CST Sun Dec 03 2023 Valid 041200Z - 051200Z ...NO CRITICAL AREAS... No changes. See previous discussion below. ..Bentley.. 12/03/2023 .PREV DISCUSSION... /ISSUED 1228 AM CST Sun Dec 03 2023/ ...Synopsis... High pressure will build in across the western US on Monday, with a dry cold frontal passage bringing cooler temperatures across much of the Plains. Weakening westerly gradients will give way to lighter southerly winds, with higher afternoon relative humidity across the central and southern Plains. As such, fire weather concerns will remain low on Monday. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 2302 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR EASTERN OH WESTERN PA AND FAR SOUTHWEST NY STATE
Mesoscale Discussion 2302 NWS Storm Prediction Center Norman OK 1236 PM CST Sun Dec 03 2023 Areas affected...eastern OH Western PA and far southwest NY State Concerning...Severe potential...Watch unlikely Valid 031836Z - 032030Z Probability of Watch Issuance...20 percent SUMMARY...A few strong to severe storms may pose a risk for a brief tornado, damaging wind gusts and small hail this afternoon. Marginal buoyancy and uncertainty about the longevity and coverage of the severe threat suggests a weather watch is unlikely. DISCUSSION...Early afternoon observations showed a compact upper-low across the southern Great Lakes region into eastern OH and western PA. At the core of this feature, very cold air (-30C 500 mb) temps were observed moving quickly east. Beneath the cold core aloft, marginally moist surface conditions (dewpoints in the upper 40s to low 50s f) and strong forcing for ascent will allow for weak destabilization through the afternoon. Partial cloud breaks should also help support 400-600 J/kg of MUCAPE with steep low-level lapse rates in the lowest 4 km allowing for strong, low-topped, updrafts to develop and quickly spread eastward. Very strong flow aloft will support elongated hodographs and favorable vertical shear for organized storms, including supercell structures and short bowing segments. Abundant vertical vorticity in the lowest levels may also support updraft rotation and vertical stretching. A brief tornado, damaging gusts, and small hail appear possible with the strongest storms able to develop. Shallow convection evident in visible imagery over east-central OH should gradually deepen through the early afternoon as they continue into PA. The latest HRRR continues these initial updrafts across PA into far southwest NY by sunset. Uncertainty still remains rather high on the intensity of individual storms and the overall longevity of the severe threat. Given these uncertainties, and the marginal thermodynamics, a WW appears unlikely at this time. ..Lyons/Hart.. 12/03/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BUF...CTP...PBZ...CLE... LAT...LON 41288075 41818024 42297925 42417866 42267824 41907799 41137820 40647866 40387916 40217971 40218038 40198071 40328089 40648100 41068088 41288075 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 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