Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1102 AM CST Wed Nov 15 2023 Valid 161200Z - 171200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... No severe thunderstorm risk is forecast across the continental United States on Thursday. ...Synopsis... A residual mid-level low and associated trough over the eastern Gulf of Mexico/FL Peninsula will slowly drift east through late Thursday night. A weakening surface low over the central Gulf of Mexico will be superceded by a developing low in between the FL Peninsula and the Bahamas. A few widely spaced thunderstorms are possible over the FL Peninsula during day, but appreciable cloudiness and/or meager lapse rates will limit thunderstorm coverage. Elsewhere, a mid-level low over the eastern Pacific will feature a few weak disturbances rotating cyclonically through the base of the larger-scale trough. A couple of lightning flashes are possible with weak convection near the coast of central CA and perhaps over the Sonoran Desert. Farther east, a surface cold front will sweep southeast from the Dakotas into the Great Lakes/Ozarks. Thunderstorms are not expected with the front. ..Smith.. 11/15/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1102 AM CST Wed Nov 15 2023 Valid 161200Z - 171200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... No severe thunderstorm risk is forecast across the continental United States on Thursday. ...Synopsis... A residual mid-level low and associated trough over the eastern Gulf of Mexico/FL Peninsula will slowly drift east through late Thursday night. A weakening surface low over the central Gulf of Mexico will be superceded by a developing low in between the FL Peninsula and the Bahamas. A few widely spaced thunderstorms are possible over the FL Peninsula during day, but appreciable cloudiness and/or meager lapse rates will limit thunderstorm coverage. Elsewhere, a mid-level low over the eastern Pacific will feature a few weak disturbances rotating cyclonically through the base of the larger-scale trough. A couple of lightning flashes are possible with weak convection near the coast of central CA and perhaps over the Sonoran Desert. Farther east, a surface cold front will sweep southeast from the Dakotas into the Great Lakes/Ozarks. Thunderstorms are not expected with the front. ..Smith.. 11/15/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1102 AM CST Wed Nov 15 2023 Valid 161200Z - 171200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... No severe thunderstorm risk is forecast across the continental United States on Thursday. ...Synopsis... A residual mid-level low and associated trough over the eastern Gulf of Mexico/FL Peninsula will slowly drift east through late Thursday night. A weakening surface low over the central Gulf of Mexico will be superceded by a developing low in between the FL Peninsula and the Bahamas. A few widely spaced thunderstorms are possible over the FL Peninsula during day, but appreciable cloudiness and/or meager lapse rates will limit thunderstorm coverage. Elsewhere, a mid-level low over the eastern Pacific will feature a few weak disturbances rotating cyclonically through the base of the larger-scale trough. A couple of lightning flashes are possible with weak convection near the coast of central CA and perhaps over the Sonoran Desert. Farther east, a surface cold front will sweep southeast from the Dakotas into the Great Lakes/Ozarks. Thunderstorms are not expected with the front. ..Smith.. 11/15/2023 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1042 AM CST Wed Nov 15 2023 Valid 151700Z - 161200Z ...NO CRITICAL AREAS... The current D1 Fire Weather Outlook remains on track with no changes needed. See previous discussion below for more information. ..Thornton.. 11/15/2023 .PREV DISCUSSION... /ISSUED 0108 AM CST Wed Nov 15 2023/ ...Synopsis... Fire weather potential appears to be limited for today across the country. Early-morning surface observations show very dry conditions along the central High Plains of CO and WY, where dewpoints are in the teens to low 20s after subsequent days of downslope warming/drying. Dry conditions are also noted across the southern Appalachians, where RH values have been in the 20-30% range over the past two days. The maintenance of a stout surface high over the East Coast will continue to favor relatively light winds over the southern Appalachians for today. To the west, increasing southwesterly flow over the inter-mountain West will support areas of breezy downslope winds. Localized elevated fire weather conditions are possible across southeast WY to northeast CO, where the potential for 15 mph overlapping with 15-20% RH seems highest. Stronger winds are expected to the west within the higher terrain, but increasing cloud cover (already noted upstream in IR imagery) should limit diurnal RH reductions. ...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 1042 AM CST Wed Nov 15 2023 Valid 151700Z - 161200Z ...NO CRITICAL AREAS... The current D1 Fire Weather Outlook remains on track with no changes needed. See previous discussion below for more information. ..Thornton.. 11/15/2023 .PREV DISCUSSION... /ISSUED 0108 AM CST Wed Nov 15 2023/ ...Synopsis... Fire weather potential appears to be limited for today across the country. Early-morning surface observations show very dry conditions along the central High Plains of CO and WY, where dewpoints are in the teens to low 20s after subsequent days of downslope warming/drying. Dry conditions are also noted across the southern Appalachians, where RH values have been in the 20-30% range over the past two days. The maintenance of a stout surface high over the East Coast will continue to favor relatively light winds over the southern Appalachians for today. To the west, increasing southwesterly flow over the inter-mountain West will support areas of breezy downslope winds. Localized elevated fire weather conditions are possible across southeast WY to northeast CO, where the potential for 15 mph overlapping with 15-20% RH seems highest. Stronger winds are expected to the west within the higher terrain, but increasing cloud cover (already noted upstream in IR imagery) should limit diurnal RH reductions. ...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 1042 AM CST Wed Nov 15 2023 Valid 151700Z - 161200Z ...NO CRITICAL AREAS... The current D1 Fire Weather Outlook remains on track with no changes needed. See previous discussion below for more information. ..Thornton.. 11/15/2023 .PREV DISCUSSION... /ISSUED 0108 AM CST Wed Nov 15 2023/ ...Synopsis... Fire weather potential appears to be limited for today across the country. Early-morning surface observations show very dry conditions along the central High Plains of CO and WY, where dewpoints are in the teens to low 20s after subsequent days of downslope warming/drying. Dry conditions are also noted across the southern Appalachians, where RH values have been in the 20-30% range over the past two days. The maintenance of a stout surface high over the East Coast will continue to favor relatively light winds over the southern Appalachians for today. To the west, increasing southwesterly flow over the inter-mountain West will support areas of breezy downslope winds. Localized elevated fire weather conditions are possible across southeast WY to northeast CO, where the potential for 15 mph overlapping with 15-20% RH seems highest. Stronger winds are expected to the west within the higher terrain, but increasing cloud cover (already noted upstream in IR imagery) should limit diurnal RH reductions. ...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 1042 AM CST Wed Nov 15 2023 Valid 151700Z - 161200Z ...NO CRITICAL AREAS... The current D1 Fire Weather Outlook remains on track with no changes needed. See previous discussion below for more information. ..Thornton.. 11/15/2023 .PREV DISCUSSION... /ISSUED 0108 AM CST Wed Nov 15 2023/ ...Synopsis... Fire weather potential appears to be limited for today across the country. Early-morning surface observations show very dry conditions along the central High Plains of CO and WY, where dewpoints are in the teens to low 20s after subsequent days of downslope warming/drying. Dry conditions are also noted across the southern Appalachians, where RH values have been in the 20-30% range over the past two days. The maintenance of a stout surface high over the East Coast will continue to favor relatively light winds over the southern Appalachians for today. To the west, increasing southwesterly flow over the inter-mountain West will support areas of breezy downslope winds. Localized elevated fire weather conditions are possible across southeast WY to northeast CO, where the potential for 15 mph overlapping with 15-20% RH seems highest. Stronger winds are expected to the west within the higher terrain, but increasing cloud cover (already noted upstream in IR imagery) should limit diurnal RH reductions. ...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 1042 AM CST Wed Nov 15 2023 Valid 151700Z - 161200Z ...NO CRITICAL AREAS... The current D1 Fire Weather Outlook remains on track with no changes needed. See previous discussion below for more information. ..Thornton.. 11/15/2023 .PREV DISCUSSION... /ISSUED 0108 AM CST Wed Nov 15 2023/ ...Synopsis... Fire weather potential appears to be limited for today across the country. Early-morning surface observations show very dry conditions along the central High Plains of CO and WY, where dewpoints are in the teens to low 20s after subsequent days of downslope warming/drying. Dry conditions are also noted across the southern Appalachians, where RH values have been in the 20-30% range over the past two days. The maintenance of a stout surface high over the East Coast will continue to favor relatively light winds over the southern Appalachians for today. To the west, increasing southwesterly flow over the inter-mountain West will support areas of breezy downslope winds. Localized elevated fire weather conditions are possible across southeast WY to northeast CO, where the potential for 15 mph overlapping with 15-20% RH seems highest. Stronger winds are expected to the west within the higher terrain, but increasing cloud cover (already noted upstream in IR imagery) should limit diurnal RH reductions. ...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 1042 AM CST Wed Nov 15 2023 Valid 151700Z - 161200Z ...NO CRITICAL AREAS... The current D1 Fire Weather Outlook remains on track with no changes needed. See previous discussion below for more information. ..Thornton.. 11/15/2023 .PREV DISCUSSION... /ISSUED 0108 AM CST Wed Nov 15 2023/ ...Synopsis... Fire weather potential appears to be limited for today across the country. Early-morning surface observations show very dry conditions along the central High Plains of CO and WY, where dewpoints are in the teens to low 20s after subsequent days of downslope warming/drying. Dry conditions are also noted across the southern Appalachians, where RH values have been in the 20-30% range over the past two days. The maintenance of a stout surface high over the East Coast will continue to favor relatively light winds over the southern Appalachians for today. To the west, increasing southwesterly flow over the inter-mountain West will support areas of breezy downslope winds. Localized elevated fire weather conditions are possible across southeast WY to northeast CO, where the potential for 15 mph overlapping with 15-20% RH seems highest. Stronger winds are expected to the west within the higher terrain, but increasing cloud cover (already noted upstream in IR imagery) should limit diurnal RH reductions. ...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 1042 AM CST Wed Nov 15 2023 Valid 151700Z - 161200Z ...NO CRITICAL AREAS... The current D1 Fire Weather Outlook remains on track with no changes needed. See previous discussion below for more information. ..Thornton.. 11/15/2023 .PREV DISCUSSION... /ISSUED 0108 AM CST Wed Nov 15 2023/ ...Synopsis... Fire weather potential appears to be limited for today across the country. Early-morning surface observations show very dry conditions along the central High Plains of CO and WY, where dewpoints are in the teens to low 20s after subsequent days of downslope warming/drying. Dry conditions are also noted across the southern Appalachians, where RH values have been in the 20-30% range over the past two days. The maintenance of a stout surface high over the East Coast will continue to favor relatively light winds over the southern Appalachians for today. To the west, increasing southwesterly flow over the inter-mountain West will support areas of breezy downslope winds. Localized elevated fire weather conditions are possible across southeast WY to northeast CO, where the potential for 15 mph overlapping with 15-20% RH seems highest. Stronger winds are expected to the west within the higher terrain, but increasing cloud cover (already noted upstream in IR imagery) should limit diurnal RH reductions. ...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 1042 AM CST Wed Nov 15 2023 Valid 151700Z - 161200Z ...NO CRITICAL AREAS... The current D1 Fire Weather Outlook remains on track with no changes needed. See previous discussion below for more information. ..Thornton.. 11/15/2023 .PREV DISCUSSION... /ISSUED 0108 AM CST Wed Nov 15 2023/ ...Synopsis... Fire weather potential appears to be limited for today across the country. Early-morning surface observations show very dry conditions along the central High Plains of CO and WY, where dewpoints are in the teens to low 20s after subsequent days of downslope warming/drying. Dry conditions are also noted across the southern Appalachians, where RH values have been in the 20-30% range over the past two days. The maintenance of a stout surface high over the East Coast will continue to favor relatively light winds over the southern Appalachians for today. To the west, increasing southwesterly flow over the inter-mountain West will support areas of breezy downslope winds. Localized elevated fire weather conditions are possible across southeast WY to northeast CO, where the potential for 15 mph overlapping with 15-20% RH seems highest. Stronger winds are expected to the west within the higher terrain, but increasing cloud cover (already noted upstream in IR imagery) should limit diurnal RH reductions. ...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 1031 AM CST Wed Nov 15 2023 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE FLORIDA KEYS INTO EXTREME SOUTHERN FLORIDA... ...SUMMARY... A brief tornado cannot be completely ruled out across portions of the Florida Keys into extreme southern Florida this afternoon and evening. ...Synopsis... Generally zonal mid-level flow will overspread much of the northern CONUS today as a pronounced upper-level trough impinges on the western U.S. and a more subtle mid-level shortwave overspreads the southern FL Peninsula. Surface high pressure and associated cooler air will remain in place across most of the Interior West to the East Coast, suppressing thunderstorm potential. However, some thunderstorm potential exists across parts of southern CA into the Great Basin in advance of the approaching mid-level trough. Thunderstorms should continue to develop through the period ahead of a meandering surface low along the Gulf coastal waters, with thunderstorm potential extending into the southern Florida Peninsula. ...Florida Keys into extreme southern Florida... Marginal buoyancy, in the form of tall/thin CAPE, remains in place across the FL keys, and is mainly driven by mid 70s F surface dewpoints beneath poor mid-level lapse rates. Through the day, the approach of the subtle mid-level trough will encourage a low-level mass response in the form of strengthening east-southeasterly 850 mb winds, which will support modestly curved hodographs. As such, any of the storms that can remain sustained within this zone of marginal instability may pose a brief tornado risk this afternoon. ..Squitieri.. 11/15/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1031 AM CST Wed Nov 15 2023 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE FLORIDA KEYS INTO EXTREME SOUTHERN FLORIDA... ...SUMMARY... A brief tornado cannot be completely ruled out across portions of the Florida Keys into extreme southern Florida this afternoon and evening. ...Synopsis... Generally zonal mid-level flow will overspread much of the northern CONUS today as a pronounced upper-level trough impinges on the western U.S. and a more subtle mid-level shortwave overspreads the southern FL Peninsula. Surface high pressure and associated cooler air will remain in place across most of the Interior West to the East Coast, suppressing thunderstorm potential. However, some thunderstorm potential exists across parts of southern CA into the Great Basin in advance of the approaching mid-level trough. Thunderstorms should continue to develop through the period ahead of a meandering surface low along the Gulf coastal waters, with thunderstorm potential extending into the southern Florida Peninsula. ...Florida Keys into extreme southern Florida... Marginal buoyancy, in the form of tall/thin CAPE, remains in place across the FL keys, and is mainly driven by mid 70s F surface dewpoints beneath poor mid-level lapse rates. Through the day, the approach of the subtle mid-level trough will encourage a low-level mass response in the form of strengthening east-southeasterly 850 mb winds, which will support modestly curved hodographs. As such, any of the storms that can remain sustained within this zone of marginal instability may pose a brief tornado risk this afternoon. ..Squitieri.. 11/15/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1031 AM CST Wed Nov 15 2023 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE FLORIDA KEYS INTO EXTREME SOUTHERN FLORIDA... ...SUMMARY... A brief tornado cannot be completely ruled out across portions of the Florida Keys into extreme southern Florida this afternoon and evening. ...Synopsis... Generally zonal mid-level flow will overspread much of the northern CONUS today as a pronounced upper-level trough impinges on the western U.S. and a more subtle mid-level shortwave overspreads the southern FL Peninsula. Surface high pressure and associated cooler air will remain in place across most of the Interior West to the East Coast, suppressing thunderstorm potential. However, some thunderstorm potential exists across parts of southern CA into the Great Basin in advance of the approaching mid-level trough. Thunderstorms should continue to develop through the period ahead of a meandering surface low along the Gulf coastal waters, with thunderstorm potential extending into the southern Florida Peninsula. ...Florida Keys into extreme southern Florida... Marginal buoyancy, in the form of tall/thin CAPE, remains in place across the FL keys, and is mainly driven by mid 70s F surface dewpoints beneath poor mid-level lapse rates. Through the day, the approach of the subtle mid-level trough will encourage a low-level mass response in the form of strengthening east-southeasterly 850 mb winds, which will support modestly curved hodographs. As such, any of the storms that can remain sustained within this zone of marginal instability may pose a brief tornado risk this afternoon. ..Squitieri.. 11/15/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1031 AM CST Wed Nov 15 2023 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE FLORIDA KEYS INTO EXTREME SOUTHERN FLORIDA... ...SUMMARY... A brief tornado cannot be completely ruled out across portions of the Florida Keys into extreme southern Florida this afternoon and evening. ...Synopsis... Generally zonal mid-level flow will overspread much of the northern CONUS today as a pronounced upper-level trough impinges on the western U.S. and a more subtle mid-level shortwave overspreads the southern FL Peninsula. Surface high pressure and associated cooler air will remain in place across most of the Interior West to the East Coast, suppressing thunderstorm potential. However, some thunderstorm potential exists across parts of southern CA into the Great Basin in advance of the approaching mid-level trough. Thunderstorms should continue to develop through the period ahead of a meandering surface low along the Gulf coastal waters, with thunderstorm potential extending into the southern Florida Peninsula. ...Florida Keys into extreme southern Florida... Marginal buoyancy, in the form of tall/thin CAPE, remains in place across the FL keys, and is mainly driven by mid 70s F surface dewpoints beneath poor mid-level lapse rates. Through the day, the approach of the subtle mid-level trough will encourage a low-level mass response in the form of strengthening east-southeasterly 850 mb winds, which will support modestly curved hodographs. As such, any of the storms that can remain sustained within this zone of marginal instability may pose a brief tornado risk this afternoon. ..Squitieri.. 11/15/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1031 AM CST Wed Nov 15 2023 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE FLORIDA KEYS INTO EXTREME SOUTHERN FLORIDA... ...SUMMARY... A brief tornado cannot be completely ruled out across portions of the Florida Keys into extreme southern Florida this afternoon and evening. ...Synopsis... Generally zonal mid-level flow will overspread much of the northern CONUS today as a pronounced upper-level trough impinges on the western U.S. and a more subtle mid-level shortwave overspreads the southern FL Peninsula. Surface high pressure and associated cooler air will remain in place across most of the Interior West to the East Coast, suppressing thunderstorm potential. However, some thunderstorm potential exists across parts of southern CA into the Great Basin in advance of the approaching mid-level trough. Thunderstorms should continue to develop through the period ahead of a meandering surface low along the Gulf coastal waters, with thunderstorm potential extending into the southern Florida Peninsula. ...Florida Keys into extreme southern Florida... Marginal buoyancy, in the form of tall/thin CAPE, remains in place across the FL keys, and is mainly driven by mid 70s F surface dewpoints beneath poor mid-level lapse rates. Through the day, the approach of the subtle mid-level trough will encourage a low-level mass response in the form of strengthening east-southeasterly 850 mb winds, which will support modestly curved hodographs. As such, any of the storms that can remain sustained within this zone of marginal instability may pose a brief tornado risk this afternoon. ..Squitieri.. 11/15/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1031 AM CST Wed Nov 15 2023 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE FLORIDA KEYS INTO EXTREME SOUTHERN FLORIDA... ...SUMMARY... A brief tornado cannot be completely ruled out across portions of the Florida Keys into extreme southern Florida this afternoon and evening. ...Synopsis... Generally zonal mid-level flow will overspread much of the northern CONUS today as a pronounced upper-level trough impinges on the western U.S. and a more subtle mid-level shortwave overspreads the southern FL Peninsula. Surface high pressure and associated cooler air will remain in place across most of the Interior West to the East Coast, suppressing thunderstorm potential. However, some thunderstorm potential exists across parts of southern CA into the Great Basin in advance of the approaching mid-level trough. Thunderstorms should continue to develop through the period ahead of a meandering surface low along the Gulf coastal waters, with thunderstorm potential extending into the southern Florida Peninsula. ...Florida Keys into extreme southern Florida... Marginal buoyancy, in the form of tall/thin CAPE, remains in place across the FL keys, and is mainly driven by mid 70s F surface dewpoints beneath poor mid-level lapse rates. Through the day, the approach of the subtle mid-level trough will encourage a low-level mass response in the form of strengthening east-southeasterly 850 mb winds, which will support modestly curved hodographs. As such, any of the storms that can remain sustained within this zone of marginal instability may pose a brief tornado risk this afternoon. ..Squitieri.. 11/15/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1031 AM CST Wed Nov 15 2023 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE FLORIDA KEYS INTO EXTREME SOUTHERN FLORIDA... ...SUMMARY... A brief tornado cannot be completely ruled out across portions of the Florida Keys into extreme southern Florida this afternoon and evening. ...Synopsis... Generally zonal mid-level flow will overspread much of the northern CONUS today as a pronounced upper-level trough impinges on the western U.S. and a more subtle mid-level shortwave overspreads the southern FL Peninsula. Surface high pressure and associated cooler air will remain in place across most of the Interior West to the East Coast, suppressing thunderstorm potential. However, some thunderstorm potential exists across parts of southern CA into the Great Basin in advance of the approaching mid-level trough. Thunderstorms should continue to develop through the period ahead of a meandering surface low along the Gulf coastal waters, with thunderstorm potential extending into the southern Florida Peninsula. ...Florida Keys into extreme southern Florida... Marginal buoyancy, in the form of tall/thin CAPE, remains in place across the FL keys, and is mainly driven by mid 70s F surface dewpoints beneath poor mid-level lapse rates. Through the day, the approach of the subtle mid-level trough will encourage a low-level mass response in the form of strengthening east-southeasterly 850 mb winds, which will support modestly curved hodographs. As such, any of the storms that can remain sustained within this zone of marginal instability may pose a brief tornado risk this afternoon. ..Squitieri.. 11/15/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1031 AM CST Wed Nov 15 2023 Valid 151630Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE FLORIDA KEYS INTO EXTREME SOUTHERN FLORIDA... ...SUMMARY... A brief tornado cannot be completely ruled out across portions of the Florida Keys into extreme southern Florida this afternoon and evening. ...Synopsis... Generally zonal mid-level flow will overspread much of the northern CONUS today as a pronounced upper-level trough impinges on the western U.S. and a more subtle mid-level shortwave overspreads the southern FL Peninsula. Surface high pressure and associated cooler air will remain in place across most of the Interior West to the East Coast, suppressing thunderstorm potential. However, some thunderstorm potential exists across parts of southern CA into the Great Basin in advance of the approaching mid-level trough. Thunderstorms should continue to develop through the period ahead of a meandering surface low along the Gulf coastal waters, with thunderstorm potential extending into the southern Florida Peninsula. ...Florida Keys into extreme southern Florida... Marginal buoyancy, in the form of tall/thin CAPE, remains in place across the FL keys, and is mainly driven by mid 70s F surface dewpoints beneath poor mid-level lapse rates. Through the day, the approach of the subtle mid-level trough will encourage a low-level mass response in the form of strengthening east-southeasterly 850 mb winds, which will support modestly curved hodographs. As such, any of the storms that can remain sustained within this zone of marginal instability may pose a brief tornado risk this afternoon. ..Squitieri.. 11/15/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0642 AM CST Wed Nov 15 2023 Valid 151300Z - 161200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast. ...Synopsis/Discussion... The synoptic/upper-air pattern over the CONUS will be dominated by three troughs (and related smaller-scale features): 1. A northern-stream perturbation, splitting eastward out of mean troughing over the northeast Pacific, across BC and the Canadian Rockies. This feature should extend across much of SK and northern/western MT by 12Z tomorrow, remaining too removed from sufficient low-level theta-e to support thunderstorm potential despite cold air aloft. 2. A Pacific cutoff low, centered around 500-550 nm off the central CA coast, forecast to drift erratically southward/southwestward through the period. A basal shortwave trough is apparent in moisture-channel imagery approaching 130W, south of the main mid/ upper low, with sporadic lightning detected. This feature should eject northeastward across parts of the central/southern CA coastline between 00-03Z, while deamplifying. An associated band of enhanced large-scale DCVA/lift should precede the trough across the region and inland, steepening mid/upper-level lapse rates over a cool, moist, stable low-level profile. Elevated MUCAPE to around 500 J/kg is possible (rooted between 700-800 mb), amidst 35-40 kt effective-shear magnitudes. This indicates that the most vigorous cells may produce small hail or locally gusty winds through the stable low-level profiles. Organized severe appears unlikely. 3. A southern-stream trough -- initially apparent from central/ southern MS to a prominent low/middle-level vorticity max near the Mississippi River mouth, then across the central Gulf toward the Yucatan Peninsula. The low-level circulation should drift erratically near its present position today, then shift farther offshore and weaken tonight, as the trough aloft starts to eject away from the low-level vortex. A low-level baroclinic zone -- extending from the low east-southeastward over parts of south FL -- should remain quasistationary through the period. Mesobeta-scale oscillations of the diffuse surface boundary are possible in response to areas of precip (including embedded thunderstorms) to its north. Lapse rates, lift and deep shear each should remain too weak for overland severe. A few weak/shallow supercells may occur around the Keys, with slightly enlarged hodographs in deep low-level eaterlies, but weak flow aloft. The greatest convective coverage/intensity should remain over the open Gulf, where marine moisture/heat fluxes are maximized into the boundary layer near the Loop Current. ..Edwards/Gleason.. 11/15/2023 Read more