Severe Storms

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CST Wed Dec 20 2023 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible on Friday from southern California across much of the Southwest. A few isolated thunderstorms are possible along the Middle Texas Coast Saturday morning as well. ...Synopsis... An upper low is expected to be centered off the southern CA coast early Friday morning before devolving into a more progressive open wave and moving eastward across the Southwest States and northern Mexico. Strong forcing for ascent, cold mid-level temperatures, and increased mid-level moisture will accompany this system, supporting the potential for thunderstorms across much of southern CA and Southwest. Isolated thunderstorms will likely be ongoing over southern CA/AZ early Friday morning, with thunderstorms expected to gradually shift eastward with parent upper system, ending with isolated thunderstorms over southeast NM and far west TX Saturday morning. Given the cold mid-level temperatures and enhanced mid-level flow through the base of this wave, a few instances of small hail are possible. Any hail should be small and sporadic enough to preclude the need for any probabilities. Low-level flow is expected to increase from south TX into the Panhandle ahead of the approaching system Friday night into Saturday morning. Eastern periphery of this increasing flow may interact with enough low-level moisture to support isolated elevated thunderstorm in the vicinity of the Middle TX Coast. ..Mosier.. 12/20/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 AM CST Wed Dec 20 2023 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible on Friday from southern California across much of the Southwest. A few isolated thunderstorms are possible along the Middle Texas Coast Saturday morning as well. ...Synopsis... An upper low is expected to be centered off the southern CA coast early Friday morning before devolving into a more progressive open wave and moving eastward across the Southwest States and northern Mexico. Strong forcing for ascent, cold mid-level temperatures, and increased mid-level moisture will accompany this system, supporting the potential for thunderstorms across much of southern CA and Southwest. Isolated thunderstorms will likely be ongoing over southern CA/AZ early Friday morning, with thunderstorms expected to gradually shift eastward with parent upper system, ending with isolated thunderstorms over southeast NM and far west TX Saturday morning. Given the cold mid-level temperatures and enhanced mid-level flow through the base of this wave, a few instances of small hail are possible. Any hail should be small and sporadic enough to preclude the need for any probabilities. Low-level flow is expected to increase from south TX into the Panhandle ahead of the approaching system Friday night into Saturday morning. Eastern periphery of this increasing flow may interact with enough low-level moisture to support isolated elevated thunderstorm in the vicinity of the Middle TX Coast. ..Mosier.. 12/20/2023 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1250 AM CST Wed Dec 20 2023 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Mid-level troughs will progress across the western and central CONUS tomorrow/Thursday, supporting continued low-level moisture return and precipitation across the Plains as cooler air remains in place over the eastern CONUS and Intermountain West. When also considering the continued precipitation accumulations over California, significant wildfire-spread potential continues to appear negligible over most of the U.S. ..Squitieri.. 12/20/2023 ...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 1250 AM CST Wed Dec 20 2023 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Mid-level troughs will progress across the western and central CONUS tomorrow/Thursday, supporting continued low-level moisture return and precipitation across the Plains as cooler air remains in place over the eastern CONUS and Intermountain West. When also considering the continued precipitation accumulations over California, significant wildfire-spread potential continues to appear negligible over most of the U.S. ..Squitieri.. 12/20/2023 ...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 1250 AM CST Wed Dec 20 2023 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Mid-level troughs will progress across the western and central CONUS tomorrow/Thursday, supporting continued low-level moisture return and precipitation across the Plains as cooler air remains in place over the eastern CONUS and Intermountain West. When also considering the continued precipitation accumulations over California, significant wildfire-spread potential continues to appear negligible over most of the U.S. ..Squitieri.. 12/20/2023 ...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 1250 AM CST Wed Dec 20 2023 Valid 211200Z - 221200Z ...NO CRITICAL AREAS... ...Synopsis... Mid-level troughs will progress across the western and central CONUS tomorrow/Thursday, supporting continued low-level moisture return and precipitation across the Plains as cooler air remains in place over the eastern CONUS and Intermountain West. When also considering the continued precipitation accumulations over California, significant wildfire-spread potential continues to appear negligible over most of the U.S. ..Squitieri.. 12/20/2023 ...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 1249 AM CST Wed Dec 20 2023 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... ...Synopsis... Upper-ridging will overspread the central and eastern U.S. as a mid-level trough meanders along the California coast today. Surface high pressure will reinforce cooler temperatures from the Mississippi River to the Atlantic coastline, as well as over the Intermountain West. Meanwhile, surface lee troughing will encourage modest moisture return across the Plains states, with the West Coast mid-level trough supporting appreciable precipitation accumulations over much of California. The culmination of the aforementioned synoptic setup will be quiescent fire-weather conditions over the CONUS. ..Squitieri.. 12/20/2023 ...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 1249 AM CST Wed Dec 20 2023 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... ...Synopsis... Upper-ridging will overspread the central and eastern U.S. as a mid-level trough meanders along the California coast today. Surface high pressure will reinforce cooler temperatures from the Mississippi River to the Atlantic coastline, as well as over the Intermountain West. Meanwhile, surface lee troughing will encourage modest moisture return across the Plains states, with the West Coast mid-level trough supporting appreciable precipitation accumulations over much of California. The culmination of the aforementioned synoptic setup will be quiescent fire-weather conditions over the CONUS. ..Squitieri.. 12/20/2023 ...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 1249 AM CST Wed Dec 20 2023 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... ...Synopsis... Upper-ridging will overspread the central and eastern U.S. as a mid-level trough meanders along the California coast today. Surface high pressure will reinforce cooler temperatures from the Mississippi River to the Atlantic coastline, as well as over the Intermountain West. Meanwhile, surface lee troughing will encourage modest moisture return across the Plains states, with the West Coast mid-level trough supporting appreciable precipitation accumulations over much of California. The culmination of the aforementioned synoptic setup will be quiescent fire-weather conditions over the CONUS. ..Squitieri.. 12/20/2023 ...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 1249 AM CST Wed Dec 20 2023 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... ...Synopsis... Upper-ridging will overspread the central and eastern U.S. as a mid-level trough meanders along the California coast today. Surface high pressure will reinforce cooler temperatures from the Mississippi River to the Atlantic coastline, as well as over the Intermountain West. Meanwhile, surface lee troughing will encourage modest moisture return across the Plains states, with the West Coast mid-level trough supporting appreciable precipitation accumulations over much of California. The culmination of the aforementioned synoptic setup will be quiescent fire-weather conditions over the CONUS. ..Squitieri.. 12/20/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1246 AM CST Wed Dec 20 2023 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are expected across coastal portions of central and southern California, as well as southern Arizona, on Thursday. ...Synopsis... A low-amplitude shortwave trough is expected to begin the period over the southern High Plains before continuing eastward throughout the day across the southern Plains. A modest moist air mass will be in place ahead of this shortwave across TX and OK, with mid 50s dewpoints likely reaching into far northwest TX. Even with this increased low-level moisture, warm mid-level temperatures and resulting poor mid-level lapse rates should temper buoyancy. A few lightning flashes may occur, but the limited buoyancy should keep the majority of updrafts too weak and shallow to produce lightning. Farther west, an upper low is forecast to be centered about 320 miles off the southern CA coast early Thursday morning. This low is expected to drift gradually southward throughout the first part of the day before then tracking more eastward towards the coast overnight and into Friday morning. Persistent forcing for ascent, ample mid-level moisture, and cold mid-level temperatures associated with this low will help support isolated thunderstorm development along the coast throughout the day. As the low moves gradually eastward, showers and thunderstorms are expected to expand eastward across southern Arizona early Friday morning. ..Mosier.. 12/20/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1246 AM CST Wed Dec 20 2023 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are expected across coastal portions of central and southern California, as well as southern Arizona, on Thursday. ...Synopsis... A low-amplitude shortwave trough is expected to begin the period over the southern High Plains before continuing eastward throughout the day across the southern Plains. A modest moist air mass will be in place ahead of this shortwave across TX and OK, with mid 50s dewpoints likely reaching into far northwest TX. Even with this increased low-level moisture, warm mid-level temperatures and resulting poor mid-level lapse rates should temper buoyancy. A few lightning flashes may occur, but the limited buoyancy should keep the majority of updrafts too weak and shallow to produce lightning. Farther west, an upper low is forecast to be centered about 320 miles off the southern CA coast early Thursday morning. This low is expected to drift gradually southward throughout the first part of the day before then tracking more eastward towards the coast overnight and into Friday morning. Persistent forcing for ascent, ample mid-level moisture, and cold mid-level temperatures associated with this low will help support isolated thunderstorm development along the coast throughout the day. As the low moves gradually eastward, showers and thunderstorms are expected to expand eastward across southern Arizona early Friday morning. ..Mosier.. 12/20/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1246 AM CST Wed Dec 20 2023 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are expected across coastal portions of central and southern California, as well as southern Arizona, on Thursday. ...Synopsis... A low-amplitude shortwave trough is expected to begin the period over the southern High Plains before continuing eastward throughout the day across the southern Plains. A modest moist air mass will be in place ahead of this shortwave across TX and OK, with mid 50s dewpoints likely reaching into far northwest TX. Even with this increased low-level moisture, warm mid-level temperatures and resulting poor mid-level lapse rates should temper buoyancy. A few lightning flashes may occur, but the limited buoyancy should keep the majority of updrafts too weak and shallow to produce lightning. Farther west, an upper low is forecast to be centered about 320 miles off the southern CA coast early Thursday morning. This low is expected to drift gradually southward throughout the first part of the day before then tracking more eastward towards the coast overnight and into Friday morning. Persistent forcing for ascent, ample mid-level moisture, and cold mid-level temperatures associated with this low will help support isolated thunderstorm development along the coast throughout the day. As the low moves gradually eastward, showers and thunderstorms are expected to expand eastward across southern Arizona early Friday morning. ..Mosier.. 12/20/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1246 AM CST Wed Dec 20 2023 Valid 211200Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are expected across coastal portions of central and southern California, as well as southern Arizona, on Thursday. ...Synopsis... A low-amplitude shortwave trough is expected to begin the period over the southern High Plains before continuing eastward throughout the day across the southern Plains. A modest moist air mass will be in place ahead of this shortwave across TX and OK, with mid 50s dewpoints likely reaching into far northwest TX. Even with this increased low-level moisture, warm mid-level temperatures and resulting poor mid-level lapse rates should temper buoyancy. A few lightning flashes may occur, but the limited buoyancy should keep the majority of updrafts too weak and shallow to produce lightning. Farther west, an upper low is forecast to be centered about 320 miles off the southern CA coast early Thursday morning. This low is expected to drift gradually southward throughout the first part of the day before then tracking more eastward towards the coast overnight and into Friday morning. Persistent forcing for ascent, ample mid-level moisture, and cold mid-level temperatures associated with this low will help support isolated thunderstorm development along the coast throughout the day. As the low moves gradually eastward, showers and thunderstorms are expected to expand eastward across southern Arizona early Friday morning. ..Mosier.. 12/20/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1143 PM CST Tue Dec 19 2023 Valid 201200Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms will be possible across parts of southern/central California and over portions of the Southwest. The severe-thunderstorm threat appears low. ...Synopsis... A deep-layer cyclone is forecast to move slowly southward off of the CA coast through the day. Downstream of this cyclone, a low-amplitude midlevel shortwave trough is forecast to move across parts of the Southwest and southern Rockies. An expansive surface ridge will cover much of the central/eastern CONUS, which should generally preclude thunderstorm development east of the Rockies. Midlevel moistening in advance of the Southwest shortwave will support elevated convection and perhaps sporadic lightning flashes across parts of AZ/NM. Somewhat more vigorous convection and greater thunderstorm coverage will be possible across parts of CA, in association with the offshore low. ...California... Deep southerly flow to the east of the offshore low will maintain modest low/midlevel moisture across near-coastal areas of southern/central CA. While the low will remain offshore through the period, a band of convection may move onshore during the day and possibly persist into the evening, in association with gradual cooling aloft and favorably difluent upper-level flow. Inland destabilization will likely remain quite limited, but increasing vertical shear may support modestly organized convection at times. A couple strong storms will be possible as stronger offshore convection approaches the coast, but instability currently appears too weak to support an organized severe-thunderstorm threat. ..Dean/Squitieri.. 12/20/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1143 PM CST Tue Dec 19 2023 Valid 201200Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms will be possible across parts of southern/central California and over portions of the Southwest. The severe-thunderstorm threat appears low. ...Synopsis... A deep-layer cyclone is forecast to move slowly southward off of the CA coast through the day. Downstream of this cyclone, a low-amplitude midlevel shortwave trough is forecast to move across parts of the Southwest and southern Rockies. An expansive surface ridge will cover much of the central/eastern CONUS, which should generally preclude thunderstorm development east of the Rockies. Midlevel moistening in advance of the Southwest shortwave will support elevated convection and perhaps sporadic lightning flashes across parts of AZ/NM. Somewhat more vigorous convection and greater thunderstorm coverage will be possible across parts of CA, in association with the offshore low. ...California... Deep southerly flow to the east of the offshore low will maintain modest low/midlevel moisture across near-coastal areas of southern/central CA. While the low will remain offshore through the period, a band of convection may move onshore during the day and possibly persist into the evening, in association with gradual cooling aloft and favorably difluent upper-level flow. Inland destabilization will likely remain quite limited, but increasing vertical shear may support modestly organized convection at times. A couple strong storms will be possible as stronger offshore convection approaches the coast, but instability currently appears too weak to support an organized severe-thunderstorm threat. ..Dean/Squitieri.. 12/20/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1143 PM CST Tue Dec 19 2023 Valid 201200Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms will be possible across parts of southern/central California and over portions of the Southwest. The severe-thunderstorm threat appears low. ...Synopsis... A deep-layer cyclone is forecast to move slowly southward off of the CA coast through the day. Downstream of this cyclone, a low-amplitude midlevel shortwave trough is forecast to move across parts of the Southwest and southern Rockies. An expansive surface ridge will cover much of the central/eastern CONUS, which should generally preclude thunderstorm development east of the Rockies. Midlevel moistening in advance of the Southwest shortwave will support elevated convection and perhaps sporadic lightning flashes across parts of AZ/NM. Somewhat more vigorous convection and greater thunderstorm coverage will be possible across parts of CA, in association with the offshore low. ...California... Deep southerly flow to the east of the offshore low will maintain modest low/midlevel moisture across near-coastal areas of southern/central CA. While the low will remain offshore through the period, a band of convection may move onshore during the day and possibly persist into the evening, in association with gradual cooling aloft and favorably difluent upper-level flow. Inland destabilization will likely remain quite limited, but increasing vertical shear may support modestly organized convection at times. A couple strong storms will be possible as stronger offshore convection approaches the coast, but instability currently appears too weak to support an organized severe-thunderstorm threat. ..Dean/Squitieri.. 12/20/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1143 PM CST Tue Dec 19 2023 Valid 201200Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms will be possible across parts of southern/central California and over portions of the Southwest. The severe-thunderstorm threat appears low. ...Synopsis... A deep-layer cyclone is forecast to move slowly southward off of the CA coast through the day. Downstream of this cyclone, a low-amplitude midlevel shortwave trough is forecast to move across parts of the Southwest and southern Rockies. An expansive surface ridge will cover much of the central/eastern CONUS, which should generally preclude thunderstorm development east of the Rockies. Midlevel moistening in advance of the Southwest shortwave will support elevated convection and perhaps sporadic lightning flashes across parts of AZ/NM. Somewhat more vigorous convection and greater thunderstorm coverage will be possible across parts of CA, in association with the offshore low. ...California... Deep southerly flow to the east of the offshore low will maintain modest low/midlevel moisture across near-coastal areas of southern/central CA. While the low will remain offshore through the period, a band of convection may move onshore during the day and possibly persist into the evening, in association with gradual cooling aloft and favorably difluent upper-level flow. Inland destabilization will likely remain quite limited, but increasing vertical shear may support modestly organized convection at times. A couple strong storms will be possible as stronger offshore convection approaches the coast, but instability currently appears too weak to support an organized severe-thunderstorm threat. ..Dean/Squitieri.. 12/20/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0645 PM CST Tue Dec 19 2023 Valid 200100Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected for the remainder of tonight. ...Synopsis... Multiple bands of generally weak convection will persist into this evening across parts of central and northern CA, to the east of a deep-layer cyclone moving southward off the northern CA coast. Weak instability may continue to support sporadic lightning flashes early this evening, before a gradual weakening trend later tonight with the onset of nocturnal cooling/stabilization. Elsewhere, generally dry and stable conditions will limit thunderstorm potential into Wednesday morning. ..Dean.. 12/20/2023 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0645 PM CST Tue Dec 19 2023 Valid 200100Z - 201200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected for the remainder of tonight. ...Synopsis... Multiple bands of generally weak convection will persist into this evening across parts of central and northern CA, to the east of a deep-layer cyclone moving southward off the northern CA coast. Weak instability may continue to support sporadic lightning flashes early this evening, before a gradual weakening trend later tonight with the onset of nocturnal cooling/stabilization. Elsewhere, generally dry and stable conditions will limit thunderstorm potential into Wednesday morning. ..Dean.. 12/20/2023 Read more