Severe Storms

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0631 PM CST Tue Nov 13 2018 Valid 140100Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected tonight. ...01Z Outlook Update... Only change to the previous outlook was to further trim the general thunder line from the west based on the progression of the cold front. Low-level moisture and instability ahead of the front (i.e. over central and southern Florida) remain supportive of isolated thunderstorms. ..Mosier.. 11/14/2018 Read more

No watches are valid as of Wed Nov 14 00:36:02 UTC 2018.

No Mesoscale Discussions are in effect as of Wed Nov 14 00:36:02 UTC 2018.

No watches are valid as of Tue Nov 13 23:53:02 UTC 2018.

No Mesoscale Discussions are in effect as of Tue Nov 13 23:53:02 UTC 2018.

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0125 PM CST Tue Nov 13 2018 Valid 132000Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today. ...20Z Outlook Update... Only minor changes have been made to the categorical (10 percent) risk of thunderstorms line, mainly to account for the progression of the cold front. The front continues to advance slowly southeastward, beneath the northwestern periphery of mid-level subtropical ridging centered over the southwestern Atlantic. Relatively warm mid-level temperatures may generally tend to suppress convection developing in response to daytime heating of the moist boundary layer over the Florida Peninsula. But a couple of showers have begun to generate a few lightning strikes, and similar such isolated to widely scattered activity may continue into this evening. ..Kerr.. 11/13/2018 .PREV DISCUSSION... /ISSUED 1021 AM CST Tue Nov 13 2018/ ...FL/GA... Virtually no changes have been made to the ongoing forecast. Scattered showers and isolated thunderstorms will be possible today and tonight over parts of southern GA and much of FL. Forecast soundings show poor lapse rates and minimal convergence/shear, suggesting that lightning activity will be limited over land, and the severe threat is low. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0125 PM CST Tue Nov 13 2018 Valid 132000Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today. ...20Z Outlook Update... Only minor changes have been made to the categorical (10 percent) risk of thunderstorms line, mainly to account for the progression of the cold front. The front continues to advance slowly southeastward, beneath the northwestern periphery of mid-level subtropical ridging centered over the southwestern Atlantic. Relatively warm mid-level temperatures may generally tend to suppress convection developing in response to daytime heating of the moist boundary layer over the Florida Peninsula. But a couple of showers have begun to generate a few lightning strikes, and similar such isolated to widely scattered activity may continue into this evening. ..Kerr.. 11/13/2018 .PREV DISCUSSION... /ISSUED 1021 AM CST Tue Nov 13 2018/ ...FL/GA... Virtually no changes have been made to the ongoing forecast. Scattered showers and isolated thunderstorms will be possible today and tonight over parts of southern GA and much of FL. Forecast soundings show poor lapse rates and minimal convergence/shear, suggesting that lightning activity will be limited over land, and the severe threat is low. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0125 PM CST Tue Nov 13 2018 Valid 132000Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today. ...20Z Outlook Update... Only minor changes have been made to the categorical (10 percent) risk of thunderstorms line, mainly to account for the progression of the cold front. The front continues to advance slowly southeastward, beneath the northwestern periphery of mid-level subtropical ridging centered over the southwestern Atlantic. Relatively warm mid-level temperatures may generally tend to suppress convection developing in response to daytime heating of the moist boundary layer over the Florida Peninsula. But a couple of showers have begun to generate a few lightning strikes, and similar such isolated to widely scattered activity may continue into this evening. ..Kerr.. 11/13/2018 .PREV DISCUSSION... /ISSUED 1021 AM CST Tue Nov 13 2018/ ...FL/GA... Virtually no changes have been made to the ongoing forecast. Scattered showers and isolated thunderstorms will be possible today and tonight over parts of southern GA and much of FL. Forecast soundings show poor lapse rates and minimal convergence/shear, suggesting that lightning activity will be limited over land, and the severe threat is low. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1249 PM CST Tue Nov 13 2018 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SAN GABRIEL MOUNTAINS VICINITY... ...CRITICAL FIRE WEATHER AREA FOR SAN JACINTO TO LAGUNA MOUNTAIN RANGES... No changes are needed to the previous forecast. The development of critical fire-weather conditions appears likely, confined mostly to the San Gabriel and San Jacinto/Laguna Mountains. Areas in between these two mountain ranges will be quite dry, but current model guidance still suggests winds will not be as strong as adjacent areas. The possibility of connecting the two critical areas will monitored in subsequent outlooks as higher-resolution model guidance becomes available. ..Karstens.. 11/13/2018 .PREV DISCUSSION... /ISSUED 0130 AM CST Tue Nov 13 2018/ ...Synopsis... With an upper-level trough in the central CONUS continuing to track eastward, the southwest CONUS will fall under a ridge during Day 2. While surface high pressure will also weaken with the departing of the upper-level trough, an inverted surface trough will remain in place cross California, maintaining a modest pressure gradient (though not as strong as previous days). With offshore flow being continuous across the area, low-level air is expected to remain quite dry, with very dry fuels in place that will continue to promote potential for fire spread/growth. ...Southern California... With at least a moderate pressure gradient established across California, relatively strong offshore flow will again be a concern across the southern California Foothills, especially during the morning hours. Latest model guidance suggests 20-30 mph sustained east-northeasterly winds will be likely during the morning hours, accompanied by critically low RH in two distinct areas, with the first area being the San Gabriel Mountain vicinity and the second being along the San Jacinto and Laguna Mountain Ranges. In addition, localized extremely critical conditions (over 30 mph winds with the critical RH) may occur for brief periods of time over these same areas, but the brevity and spatially constricted nature of these conditions precludes an extremely critical delineation. From the afternoon to the end of the period, a gradual weakening trend in wind speeds are expected, with elevated to critical conditions persisting, as critically low RH and very dry fuels will continue to support wildfire spread. ...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 1249 PM CST Tue Nov 13 2018 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SAN GABRIEL MOUNTAINS VICINITY... ...CRITICAL FIRE WEATHER AREA FOR SAN JACINTO TO LAGUNA MOUNTAIN RANGES... No changes are needed to the previous forecast. The development of critical fire-weather conditions appears likely, confined mostly to the San Gabriel and San Jacinto/Laguna Mountains. Areas in between these two mountain ranges will be quite dry, but current model guidance still suggests winds will not be as strong as adjacent areas. The possibility of connecting the two critical areas will monitored in subsequent outlooks as higher-resolution model guidance becomes available. ..Karstens.. 11/13/2018 .PREV DISCUSSION... /ISSUED 0130 AM CST Tue Nov 13 2018/ ...Synopsis... With an upper-level trough in the central CONUS continuing to track eastward, the southwest CONUS will fall under a ridge during Day 2. While surface high pressure will also weaken with the departing of the upper-level trough, an inverted surface trough will remain in place cross California, maintaining a modest pressure gradient (though not as strong as previous days). With offshore flow being continuous across the area, low-level air is expected to remain quite dry, with very dry fuels in place that will continue to promote potential for fire spread/growth. ...Southern California... With at least a moderate pressure gradient established across California, relatively strong offshore flow will again be a concern across the southern California Foothills, especially during the morning hours. Latest model guidance suggests 20-30 mph sustained east-northeasterly winds will be likely during the morning hours, accompanied by critically low RH in two distinct areas, with the first area being the San Gabriel Mountain vicinity and the second being along the San Jacinto and Laguna Mountain Ranges. In addition, localized extremely critical conditions (over 30 mph winds with the critical RH) may occur for brief periods of time over these same areas, but the brevity and spatially constricted nature of these conditions precludes an extremely critical delineation. From the afternoon to the end of the period, a gradual weakening trend in wind speeds are expected, with elevated to critical conditions persisting, as critically low RH and very dry fuels will continue to support wildfire spread. ...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 1249 PM CST Tue Nov 13 2018 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SAN GABRIEL MOUNTAINS VICINITY... ...CRITICAL FIRE WEATHER AREA FOR SAN JACINTO TO LAGUNA MOUNTAIN RANGES... No changes are needed to the previous forecast. The development of critical fire-weather conditions appears likely, confined mostly to the San Gabriel and San Jacinto/Laguna Mountains. Areas in between these two mountain ranges will be quite dry, but current model guidance still suggests winds will not be as strong as adjacent areas. The possibility of connecting the two critical areas will monitored in subsequent outlooks as higher-resolution model guidance becomes available. ..Karstens.. 11/13/2018 .PREV DISCUSSION... /ISSUED 0130 AM CST Tue Nov 13 2018/ ...Synopsis... With an upper-level trough in the central CONUS continuing to track eastward, the southwest CONUS will fall under a ridge during Day 2. While surface high pressure will also weaken with the departing of the upper-level trough, an inverted surface trough will remain in place cross California, maintaining a modest pressure gradient (though not as strong as previous days). With offshore flow being continuous across the area, low-level air is expected to remain quite dry, with very dry fuels in place that will continue to promote potential for fire spread/growth. ...Southern California... With at least a moderate pressure gradient established across California, relatively strong offshore flow will again be a concern across the southern California Foothills, especially during the morning hours. Latest model guidance suggests 20-30 mph sustained east-northeasterly winds will be likely during the morning hours, accompanied by critically low RH in two distinct areas, with the first area being the San Gabriel Mountain vicinity and the second being along the San Jacinto and Laguna Mountain Ranges. In addition, localized extremely critical conditions (over 30 mph winds with the critical RH) may occur for brief periods of time over these same areas, but the brevity and spatially constricted nature of these conditions precludes an extremely critical delineation. From the afternoon to the end of the period, a gradual weakening trend in wind speeds are expected, with elevated to critical conditions persisting, as critically low RH and very dry fuels will continue to support wildfire spread. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1101 AM CST Tue Nov 13 2018 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms appears negligible across the U.S. Wednesday through Wednesday night. ...Discussion... The westerlies appear likely to trend less amplified, but cold/dry and/or stable conditions now present across much of the nation will be slow to modify through this period. Models do continue to indicate that fairly significant lower/mid tropospheric cyclogenesis may occur within a remnant southern branch of mid-latitude westerlies, from the southern Plains through the Mid South region by late Wednesday night. This will occur generally above/to the northwest of the shallow leading edge of the ongoing low-level arctic intrusion, which is expected to advance off the south Atlantic coast, into northern Florida, and through much of the northern/western Gulf of Mexico by 12Z Wednesday. However, it appears that associated forcing will contribute to a developing surface low across the Tennessee Valley, and a bit more prominent surface frontal wave from the northeastern Gulf of Mexico into the vicinity of the South Carolina coast, Wednesday through Wednesday night. This may be accompanied by sufficient destabilization to support a risk for weak thunderstorm activity above the cold/stable surface based air, mainly along the frontal zone across parts of northern Florida and the Florida Panhandle into the piedmont and coastal plain of the Carolinas. However, the spread among the various model output appears sizable concerning the extent of this potential, and the possibility of isolated thunderstorm activity across the Florida Peninsula. Highest thunderstorm probabilities probably will remain focused along the front east of the south Atlantic coast, and perhaps across parts of the southeastern Gulf of Mexico. Across and inland of coastal areas, the risk for severe storms still appears negligible. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: <5% - None Hail: <5% - None ..Kerr.. 11/13/2018 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1101 AM CST Tue Nov 13 2018 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms appears negligible across the U.S. Wednesday through Wednesday night. ...Discussion... The westerlies appear likely to trend less amplified, but cold/dry and/or stable conditions now present across much of the nation will be slow to modify through this period. Models do continue to indicate that fairly significant lower/mid tropospheric cyclogenesis may occur within a remnant southern branch of mid-latitude westerlies, from the southern Plains through the Mid South region by late Wednesday night. This will occur generally above/to the northwest of the shallow leading edge of the ongoing low-level arctic intrusion, which is expected to advance off the south Atlantic coast, into northern Florida, and through much of the northern/western Gulf of Mexico by 12Z Wednesday. However, it appears that associated forcing will contribute to a developing surface low across the Tennessee Valley, and a bit more prominent surface frontal wave from the northeastern Gulf of Mexico into the vicinity of the South Carolina coast, Wednesday through Wednesday night. This may be accompanied by sufficient destabilization to support a risk for weak thunderstorm activity above the cold/stable surface based air, mainly along the frontal zone across parts of northern Florida and the Florida Panhandle into the piedmont and coastal plain of the Carolinas. However, the spread among the various model output appears sizable concerning the extent of this potential, and the possibility of isolated thunderstorm activity across the Florida Peninsula. Highest thunderstorm probabilities probably will remain focused along the front east of the south Atlantic coast, and perhaps across parts of the southeastern Gulf of Mexico. Across and inland of coastal areas, the risk for severe storms still appears negligible. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: <5% - None Hail: <5% - None ..Kerr.. 11/13/2018 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1101 AM CST Tue Nov 13 2018 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms appears negligible across the U.S. Wednesday through Wednesday night. ...Discussion... The westerlies appear likely to trend less amplified, but cold/dry and/or stable conditions now present across much of the nation will be slow to modify through this period. Models do continue to indicate that fairly significant lower/mid tropospheric cyclogenesis may occur within a remnant southern branch of mid-latitude westerlies, from the southern Plains through the Mid South region by late Wednesday night. This will occur generally above/to the northwest of the shallow leading edge of the ongoing low-level arctic intrusion, which is expected to advance off the south Atlantic coast, into northern Florida, and through much of the northern/western Gulf of Mexico by 12Z Wednesday. However, it appears that associated forcing will contribute to a developing surface low across the Tennessee Valley, and a bit more prominent surface frontal wave from the northeastern Gulf of Mexico into the vicinity of the South Carolina coast, Wednesday through Wednesday night. This may be accompanied by sufficient destabilization to support a risk for weak thunderstorm activity above the cold/stable surface based air, mainly along the frontal zone across parts of northern Florida and the Florida Panhandle into the piedmont and coastal plain of the Carolinas. However, the spread among the various model output appears sizable concerning the extent of this potential, and the possibility of isolated thunderstorm activity across the Florida Peninsula. Highest thunderstorm probabilities probably will remain focused along the front east of the south Atlantic coast, and perhaps across parts of the southeastern Gulf of Mexico. Across and inland of coastal areas, the risk for severe storms still appears negligible. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: <5% - None Hail: <5% - None ..Kerr.. 11/13/2018 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1101 AM CST Tue Nov 13 2018 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for severe thunderstorms appears negligible across the U.S. Wednesday through Wednesday night. ...Discussion... The westerlies appear likely to trend less amplified, but cold/dry and/or stable conditions now present across much of the nation will be slow to modify through this period. Models do continue to indicate that fairly significant lower/mid tropospheric cyclogenesis may occur within a remnant southern branch of mid-latitude westerlies, from the southern Plains through the Mid South region by late Wednesday night. This will occur generally above/to the northwest of the shallow leading edge of the ongoing low-level arctic intrusion, which is expected to advance off the south Atlantic coast, into northern Florida, and through much of the northern/western Gulf of Mexico by 12Z Wednesday. However, it appears that associated forcing will contribute to a developing surface low across the Tennessee Valley, and a bit more prominent surface frontal wave from the northeastern Gulf of Mexico into the vicinity of the South Carolina coast, Wednesday through Wednesday night. This may be accompanied by sufficient destabilization to support a risk for weak thunderstorm activity above the cold/stable surface based air, mainly along the frontal zone across parts of northern Florida and the Florida Panhandle into the piedmont and coastal plain of the Carolinas. However, the spread among the various model output appears sizable concerning the extent of this potential, and the possibility of isolated thunderstorm activity across the Florida Peninsula. Highest thunderstorm probabilities probably will remain focused along the front east of the south Atlantic coast, and perhaps across parts of the southeastern Gulf of Mexico. Across and inland of coastal areas, the risk for severe storms still appears negligible. ...MAXIMUM RISK BY HAZARD... Tornado: <2% - None Wind: <5% - None Hail: <5% - None ..Kerr.. 11/13/2018 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1021 AM CST Tue Nov 13 2018 Valid 131630Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today. ...FL/GA... Virtually no changes have been made to the ongoing forecast. Scattered showers and isolated thunderstorms will be possible today and tonight over parts of southern GA and much of FL. Forecast soundings show poor lapse rates and minimal convergence/shear, suggesting that lightning activity will be limited over land, and the severe threat is low. ..Hart/Bentley.. 11/13/2018 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1021 AM CST Tue Nov 13 2018 Valid 131630Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today. ...FL/GA... Virtually no changes have been made to the ongoing forecast. Scattered showers and isolated thunderstorms will be possible today and tonight over parts of southern GA and much of FL. Forecast soundings show poor lapse rates and minimal convergence/shear, suggesting that lightning activity will be limited over land, and the severe threat is low. ..Hart/Bentley.. 11/13/2018 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1021 AM CST Tue Nov 13 2018 Valid 131630Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today. ...FL/GA... Virtually no changes have been made to the ongoing forecast. Scattered showers and isolated thunderstorms will be possible today and tonight over parts of southern GA and much of FL. Forecast soundings show poor lapse rates and minimal convergence/shear, suggesting that lightning activity will be limited over land, and the severe threat is low. ..Hart/Bentley.. 11/13/2018 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1021 AM CST Tue Nov 13 2018 Valid 131630Z - 141200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today. ...FL/GA... Virtually no changes have been made to the ongoing forecast. Scattered showers and isolated thunderstorms will be possible today and tonight over parts of southern GA and much of FL. Forecast soundings show poor lapse rates and minimal convergence/shear, suggesting that lightning activity will be limited over land, and the severe threat is low. ..Hart/Bentley.. 11/13/2018 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1005 AM CST Tue Nov 13 2018 Valid 131700Z - 141200Z ...EXTREMELY CRITICAL FIRE WEATHER AREA FOR SAN JACINTO TO LAGUNA MOUNTAIN RANGES... ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN CALIFORNIA... No changes are needed to the ongoing forecast. Extreme fire-weather conditions will develop by late morning into the afternoon across portions of Southern California. See the discussion below for additional details. ..Karstens.. 11/13/2018 .PREV DISCUSSION... /ISSUED 1234 AM CST Tue Nov 13 2018/ ...Synopsis... As a mid-level trough and associated surface high continue to move away from the southwest CONUS during the day, the strong pressure gradient will begin to considerably weaken, especially by afternoon. Consequently, surface fire weather conditions across portions of California will become progressively less favorable with time, compared to previous days. ...Southern California... During the morning hours, 20+ mph offshore flow, associated with a tightened pressure gradient, will prevail across southwest California, in tandem with critically low RH and very fuels supported of rapid fire growth/spread. Across the higher terrain and slopes of the San Jacinto to Laguna Mountain Ranges, sustained wind speeds of 30-40 mph may be observed, along with single-digit RH values. This surface wind/RH combination will yield a volatile environment, capable of supporting very rapid fire growth, hence the continuation of an extremely critical risk in this area. Similar conditions may also locally occur along the slopes of the San Gabriel mountains, to the Santa Monica mountains, but the brevity/localized nature of these stronger winds/lower RH precludes an extremely critical delineation over this area. By afternoon, deep-tropospheric mixing of weaker flow aloft, combined with the weakening of the synoptic scale gradient, will lead to winds subsiding to elevated/critical conditions for the remainder of the period. ...Please see www.spc.noaa.gov/fire for graphic product... Read more