Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1153 AM CDT Tue Oct 31 2023 Valid 011200Z - 021200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears low on Wednesday. ...Synopsis... A mid/upper-level shortwave trough initially over the lower Great Lakes region is forecast to move quickly northeastward toward northern New England and the Canadian Maritimes on Wednesday. In its wake, a broad upper trough will remain in place across much of the central/eastern CONUS. Farther west, a low-amplitude midlevel shortwave trough will approach the Pacific Northwest during the afternoon/evening. Dry and stable conditions resulting from cold surface ridging will continue to limit thunderstorm potential over most of the CONUS. While some weak convection could accompany the shortwave trough and attendant precipitation shield across the Pacific Northwest, instability currently appears too weak to support any substantial thunderstorm potential through the forecast period. ..Dean.. 10/31/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1153 AM CDT Tue Oct 31 2023 Valid 011200Z - 021200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears low on Wednesday. ...Synopsis... A mid/upper-level shortwave trough initially over the lower Great Lakes region is forecast to move quickly northeastward toward northern New England and the Canadian Maritimes on Wednesday. In its wake, a broad upper trough will remain in place across much of the central/eastern CONUS. Farther west, a low-amplitude midlevel shortwave trough will approach the Pacific Northwest during the afternoon/evening. Dry and stable conditions resulting from cold surface ridging will continue to limit thunderstorm potential over most of the CONUS. While some weak convection could accompany the shortwave trough and attendant precipitation shield across the Pacific Northwest, instability currently appears too weak to support any substantial thunderstorm potential through the forecast period. ..Dean.. 10/31/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1153 AM CDT Tue Oct 31 2023 Valid 011200Z - 021200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears low on Wednesday. ...Synopsis... A mid/upper-level shortwave trough initially over the lower Great Lakes region is forecast to move quickly northeastward toward northern New England and the Canadian Maritimes on Wednesday. In its wake, a broad upper trough will remain in place across much of the central/eastern CONUS. Farther west, a low-amplitude midlevel shortwave trough will approach the Pacific Northwest during the afternoon/evening. Dry and stable conditions resulting from cold surface ridging will continue to limit thunderstorm potential over most of the CONUS. While some weak convection could accompany the shortwave trough and attendant precipitation shield across the Pacific Northwest, instability currently appears too weak to support any substantial thunderstorm potential through the forecast period. ..Dean.. 10/31/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1153 AM CDT Tue Oct 31 2023 Valid 011200Z - 021200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears low on Wednesday. ...Synopsis... A mid/upper-level shortwave trough initially over the lower Great Lakes region is forecast to move quickly northeastward toward northern New England and the Canadian Maritimes on Wednesday. In its wake, a broad upper trough will remain in place across much of the central/eastern CONUS. Farther west, a low-amplitude midlevel shortwave trough will approach the Pacific Northwest during the afternoon/evening. Dry and stable conditions resulting from cold surface ridging will continue to limit thunderstorm potential over most of the CONUS. While some weak convection could accompany the shortwave trough and attendant precipitation shield across the Pacific Northwest, instability currently appears too weak to support any substantial thunderstorm potential through the forecast period. ..Dean.. 10/31/2023 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1153 AM CDT Tue Oct 31 2023 Valid 011200Z - 021200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears low on Wednesday. ...Synopsis... A mid/upper-level shortwave trough initially over the lower Great Lakes region is forecast to move quickly northeastward toward northern New England and the Canadian Maritimes on Wednesday. In its wake, a broad upper trough will remain in place across much of the central/eastern CONUS. Farther west, a low-amplitude midlevel shortwave trough will approach the Pacific Northwest during the afternoon/evening. Dry and stable conditions resulting from cold surface ridging will continue to limit thunderstorm potential over most of the CONUS. While some weak convection could accompany the shortwave trough and attendant precipitation shield across the Pacific Northwest, instability currently appears too weak to support any substantial thunderstorm potential through the forecast period. ..Dean.. 10/31/2023 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1140 AM CDT Tue Oct 31 2023 Valid 311700Z - 011200Z ...Southern California... The latest observations from 16 UTC indicate that Elevated to locally Critical fire weather conditions continue across the wind prone mountains and valleys of Los Angeles and Ventura Counties, with poor overnight RH recoveries near 5-10% and sustained wind speeds of 20-30 mph atop at least modestly receptive fuels. While sustained winds speeds are forecast to decrease across the area beginning this afternoon as the surface pressure gradient weakens, locally Elevated fire weather conditions will remain possible as lingering breeziness overlaps a very dry air mass. ...Southeast... Elevated to locally Critical fire weather conditions are likely today across portions of Louisiana, Mississippi, Alabama, and Georgia in the wake of a mostly-dry cold front (generally less than 0.1 inch of rain was observed). The primary adjustment with this forecast update was to expand the Elevated area slightly in all directions to account for recent trends in weather and fuel guidance. Despite high temperatures only reaching the 50s, the dry post-frontal dry air (minimum RH values near 25-30%) combined with sustained wind speeds near 15 mph and critically receptive fuels (Moderate to Exceptional drought across parts of these areas in the U.S. Drought Monitor) should allow for several hours of Elevated to locally Critical conditions this afternoon and early evening. ..Elliott.. 10/31/2023 .PREV DISCUSSION... /ISSUED 0107 AM CDT Tue Oct 31 2023/ ...Synopsis... A mid-level trough and accompanying surface anticyclone will traverse the central and eastern CONUS today, supporting the southeastward surge of cooler, drier air across the Southeast. Here, RH may dip below 30 percent in the post-cold-frontal airmass, with 10-15 mph sustained northwesterly surface winds supporting Elevated meteorological conditions across portions of central Louisiana into central Mississippi and Alabama. The eastern shunt of the surface anticyclone will relax the pressure gradient across southern California. While dry offshore flow will persist into the morning hours (hence the Elevated highlights), offshore wind speeds should subside with time, tempering the wildfire-spread threat later in the day. ...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 1140 AM CDT Tue Oct 31 2023 Valid 311700Z - 011200Z ...Southern California... The latest observations from 16 UTC indicate that Elevated to locally Critical fire weather conditions continue across the wind prone mountains and valleys of Los Angeles and Ventura Counties, with poor overnight RH recoveries near 5-10% and sustained wind speeds of 20-30 mph atop at least modestly receptive fuels. While sustained winds speeds are forecast to decrease across the area beginning this afternoon as the surface pressure gradient weakens, locally Elevated fire weather conditions will remain possible as lingering breeziness overlaps a very dry air mass. ...Southeast... Elevated to locally Critical fire weather conditions are likely today across portions of Louisiana, Mississippi, Alabama, and Georgia in the wake of a mostly-dry cold front (generally less than 0.1 inch of rain was observed). The primary adjustment with this forecast update was to expand the Elevated area slightly in all directions to account for recent trends in weather and fuel guidance. Despite high temperatures only reaching the 50s, the dry post-frontal dry air (minimum RH values near 25-30%) combined with sustained wind speeds near 15 mph and critically receptive fuels (Moderate to Exceptional drought across parts of these areas in the U.S. Drought Monitor) should allow for several hours of Elevated to locally Critical conditions this afternoon and early evening. ..Elliott.. 10/31/2023 .PREV DISCUSSION... /ISSUED 0107 AM CDT Tue Oct 31 2023/ ...Synopsis... A mid-level trough and accompanying surface anticyclone will traverse the central and eastern CONUS today, supporting the southeastward surge of cooler, drier air across the Southeast. Here, RH may dip below 30 percent in the post-cold-frontal airmass, with 10-15 mph sustained northwesterly surface winds supporting Elevated meteorological conditions across portions of central Louisiana into central Mississippi and Alabama. The eastern shunt of the surface anticyclone will relax the pressure gradient across southern California. While dry offshore flow will persist into the morning hours (hence the Elevated highlights), offshore wind speeds should subside with time, tempering the wildfire-spread threat later in the day. ...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 1140 AM CDT Tue Oct 31 2023 Valid 311700Z - 011200Z ...Southern California... The latest observations from 16 UTC indicate that Elevated to locally Critical fire weather conditions continue across the wind prone mountains and valleys of Los Angeles and Ventura Counties, with poor overnight RH recoveries near 5-10% and sustained wind speeds of 20-30 mph atop at least modestly receptive fuels. While sustained winds speeds are forecast to decrease across the area beginning this afternoon as the surface pressure gradient weakens, locally Elevated fire weather conditions will remain possible as lingering breeziness overlaps a very dry air mass. ...Southeast... Elevated to locally Critical fire weather conditions are likely today across portions of Louisiana, Mississippi, Alabama, and Georgia in the wake of a mostly-dry cold front (generally less than 0.1 inch of rain was observed). The primary adjustment with this forecast update was to expand the Elevated area slightly in all directions to account for recent trends in weather and fuel guidance. Despite high temperatures only reaching the 50s, the dry post-frontal dry air (minimum RH values near 25-30%) combined with sustained wind speeds near 15 mph and critically receptive fuels (Moderate to Exceptional drought across parts of these areas in the U.S. Drought Monitor) should allow for several hours of Elevated to locally Critical conditions this afternoon and early evening. ..Elliott.. 10/31/2023 .PREV DISCUSSION... /ISSUED 0107 AM CDT Tue Oct 31 2023/ ...Synopsis... A mid-level trough and accompanying surface anticyclone will traverse the central and eastern CONUS today, supporting the southeastward surge of cooler, drier air across the Southeast. Here, RH may dip below 30 percent in the post-cold-frontal airmass, with 10-15 mph sustained northwesterly surface winds supporting Elevated meteorological conditions across portions of central Louisiana into central Mississippi and Alabama. The eastern shunt of the surface anticyclone will relax the pressure gradient across southern California. While dry offshore flow will persist into the morning hours (hence the Elevated highlights), offshore wind speeds should subside with time, tempering the wildfire-spread threat later in the day. ...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 1140 AM CDT Tue Oct 31 2023 Valid 311700Z - 011200Z ...Southern California... The latest observations from 16 UTC indicate that Elevated to locally Critical fire weather conditions continue across the wind prone mountains and valleys of Los Angeles and Ventura Counties, with poor overnight RH recoveries near 5-10% and sustained wind speeds of 20-30 mph atop at least modestly receptive fuels. While sustained winds speeds are forecast to decrease across the area beginning this afternoon as the surface pressure gradient weakens, locally Elevated fire weather conditions will remain possible as lingering breeziness overlaps a very dry air mass. ...Southeast... Elevated to locally Critical fire weather conditions are likely today across portions of Louisiana, Mississippi, Alabama, and Georgia in the wake of a mostly-dry cold front (generally less than 0.1 inch of rain was observed). The primary adjustment with this forecast update was to expand the Elevated area slightly in all directions to account for recent trends in weather and fuel guidance. Despite high temperatures only reaching the 50s, the dry post-frontal dry air (minimum RH values near 25-30%) combined with sustained wind speeds near 15 mph and critically receptive fuels (Moderate to Exceptional drought across parts of these areas in the U.S. Drought Monitor) should allow for several hours of Elevated to locally Critical conditions this afternoon and early evening. ..Elliott.. 10/31/2023 .PREV DISCUSSION... /ISSUED 0107 AM CDT Tue Oct 31 2023/ ...Synopsis... A mid-level trough and accompanying surface anticyclone will traverse the central and eastern CONUS today, supporting the southeastward surge of cooler, drier air across the Southeast. Here, RH may dip below 30 percent in the post-cold-frontal airmass, with 10-15 mph sustained northwesterly surface winds supporting Elevated meteorological conditions across portions of central Louisiana into central Mississippi and Alabama. The eastern shunt of the surface anticyclone will relax the pressure gradient across southern California. While dry offshore flow will persist into the morning hours (hence the Elevated highlights), offshore wind speeds should subside with time, tempering the wildfire-spread threat later in the day. ...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 1140 AM CDT Tue Oct 31 2023 Valid 311700Z - 011200Z ...Southern California... The latest observations from 16 UTC indicate that Elevated to locally Critical fire weather conditions continue across the wind prone mountains and valleys of Los Angeles and Ventura Counties, with poor overnight RH recoveries near 5-10% and sustained wind speeds of 20-30 mph atop at least modestly receptive fuels. While sustained winds speeds are forecast to decrease across the area beginning this afternoon as the surface pressure gradient weakens, locally Elevated fire weather conditions will remain possible as lingering breeziness overlaps a very dry air mass. ...Southeast... Elevated to locally Critical fire weather conditions are likely today across portions of Louisiana, Mississippi, Alabama, and Georgia in the wake of a mostly-dry cold front (generally less than 0.1 inch of rain was observed). The primary adjustment with this forecast update was to expand the Elevated area slightly in all directions to account for recent trends in weather and fuel guidance. Despite high temperatures only reaching the 50s, the dry post-frontal dry air (minimum RH values near 25-30%) combined with sustained wind speeds near 15 mph and critically receptive fuels (Moderate to Exceptional drought across parts of these areas in the U.S. Drought Monitor) should allow for several hours of Elevated to locally Critical conditions this afternoon and early evening. ..Elliott.. 10/31/2023 .PREV DISCUSSION... /ISSUED 0107 AM CDT Tue Oct 31 2023/ ...Synopsis... A mid-level trough and accompanying surface anticyclone will traverse the central and eastern CONUS today, supporting the southeastward surge of cooler, drier air across the Southeast. Here, RH may dip below 30 percent in the post-cold-frontal airmass, with 10-15 mph sustained northwesterly surface winds supporting Elevated meteorological conditions across portions of central Louisiana into central Mississippi and Alabama. The eastern shunt of the surface anticyclone will relax the pressure gradient across southern California. While dry offshore flow will persist into the morning hours (hence the Elevated highlights), offshore wind speeds should subside with time, tempering the wildfire-spread threat later in the day. ...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 1140 AM CDT Tue Oct 31 2023 Valid 311700Z - 011200Z ...Southern California... The latest observations from 16 UTC indicate that Elevated to locally Critical fire weather conditions continue across the wind prone mountains and valleys of Los Angeles and Ventura Counties, with poor overnight RH recoveries near 5-10% and sustained wind speeds of 20-30 mph atop at least modestly receptive fuels. While sustained winds speeds are forecast to decrease across the area beginning this afternoon as the surface pressure gradient weakens, locally Elevated fire weather conditions will remain possible as lingering breeziness overlaps a very dry air mass. ...Southeast... Elevated to locally Critical fire weather conditions are likely today across portions of Louisiana, Mississippi, Alabama, and Georgia in the wake of a mostly-dry cold front (generally less than 0.1 inch of rain was observed). The primary adjustment with this forecast update was to expand the Elevated area slightly in all directions to account for recent trends in weather and fuel guidance. Despite high temperatures only reaching the 50s, the dry post-frontal dry air (minimum RH values near 25-30%) combined with sustained wind speeds near 15 mph and critically receptive fuels (Moderate to Exceptional drought across parts of these areas in the U.S. Drought Monitor) should allow for several hours of Elevated to locally Critical conditions this afternoon and early evening. ..Elliott.. 10/31/2023 .PREV DISCUSSION... /ISSUED 0107 AM CDT Tue Oct 31 2023/ ...Synopsis... A mid-level trough and accompanying surface anticyclone will traverse the central and eastern CONUS today, supporting the southeastward surge of cooler, drier air across the Southeast. Here, RH may dip below 30 percent in the post-cold-frontal airmass, with 10-15 mph sustained northwesterly surface winds supporting Elevated meteorological conditions across portions of central Louisiana into central Mississippi and Alabama. The eastern shunt of the surface anticyclone will relax the pressure gradient across southern California. While dry offshore flow will persist into the morning hours (hence the Elevated highlights), offshore wind speeds should subside with time, tempering the wildfire-spread threat later in the day. ...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 1140 AM CDT Tue Oct 31 2023 Valid 311700Z - 011200Z ...Southern California... The latest observations from 16 UTC indicate that Elevated to locally Critical fire weather conditions continue across the wind prone mountains and valleys of Los Angeles and Ventura Counties, with poor overnight RH recoveries near 5-10% and sustained wind speeds of 20-30 mph atop at least modestly receptive fuels. While sustained winds speeds are forecast to decrease across the area beginning this afternoon as the surface pressure gradient weakens, locally Elevated fire weather conditions will remain possible as lingering breeziness overlaps a very dry air mass. ...Southeast... Elevated to locally Critical fire weather conditions are likely today across portions of Louisiana, Mississippi, Alabama, and Georgia in the wake of a mostly-dry cold front (generally less than 0.1 inch of rain was observed). The primary adjustment with this forecast update was to expand the Elevated area slightly in all directions to account for recent trends in weather and fuel guidance. Despite high temperatures only reaching the 50s, the dry post-frontal dry air (minimum RH values near 25-30%) combined with sustained wind speeds near 15 mph and critically receptive fuels (Moderate to Exceptional drought across parts of these areas in the U.S. Drought Monitor) should allow for several hours of Elevated to locally Critical conditions this afternoon and early evening. ..Elliott.. 10/31/2023 .PREV DISCUSSION... /ISSUED 0107 AM CDT Tue Oct 31 2023/ ...Synopsis... A mid-level trough and accompanying surface anticyclone will traverse the central and eastern CONUS today, supporting the southeastward surge of cooler, drier air across the Southeast. Here, RH may dip below 30 percent in the post-cold-frontal airmass, with 10-15 mph sustained northwesterly surface winds supporting Elevated meteorological conditions across portions of central Louisiana into central Mississippi and Alabama. The eastern shunt of the surface anticyclone will relax the pressure gradient across southern California. While dry offshore flow will persist into the morning hours (hence the Elevated highlights), offshore wind speeds should subside with time, tempering the wildfire-spread threat later in the day. ...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 1103 AM CDT Tue Oct 31 2023 Valid 311630Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible over parts of the Great Lakes and immediate vicinity, as well as off the southeastern Florida coast. ...Synopsis... Thunderstorm potential today is expected to remain largely over the Great Lakes and off the southeastern Florida Coast. A compact upper low is evident in mid-morning satellite imagery over southern WI/northern IL. This feature is expected to begin tracking to the east over the next 12 hours in tandem with the mean upper trough. 12 UTC soundings across the Midwest and Great Lakes sampled very cold temperatures aloft associated with this feature (500 mb temperatures between -30 to -40 C), which will overspread the warmer waters of the Great Lakes through the afternoon and evening. While buoyancy will be minimal, lapse rates should be sufficiently steep to support occasional lightning flashes over the Lakes and along the lake shores. Isolated thunderstorms are also possible along a residual boundary off the southeastern FL coast; however, convection should remain offshore. ..Moore/Thornton.. 10/31/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1103 AM CDT Tue Oct 31 2023 Valid 311630Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible over parts of the Great Lakes and immediate vicinity, as well as off the southeastern Florida coast. ...Synopsis... Thunderstorm potential today is expected to remain largely over the Great Lakes and off the southeastern Florida Coast. A compact upper low is evident in mid-morning satellite imagery over southern WI/northern IL. This feature is expected to begin tracking to the east over the next 12 hours in tandem with the mean upper trough. 12 UTC soundings across the Midwest and Great Lakes sampled very cold temperatures aloft associated with this feature (500 mb temperatures between -30 to -40 C), which will overspread the warmer waters of the Great Lakes through the afternoon and evening. While buoyancy will be minimal, lapse rates should be sufficiently steep to support occasional lightning flashes over the Lakes and along the lake shores. Isolated thunderstorms are also possible along a residual boundary off the southeastern FL coast; however, convection should remain offshore. ..Moore/Thornton.. 10/31/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1103 AM CDT Tue Oct 31 2023 Valid 311630Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible over parts of the Great Lakes and immediate vicinity, as well as off the southeastern Florida coast. ...Synopsis... Thunderstorm potential today is expected to remain largely over the Great Lakes and off the southeastern Florida Coast. A compact upper low is evident in mid-morning satellite imagery over southern WI/northern IL. This feature is expected to begin tracking to the east over the next 12 hours in tandem with the mean upper trough. 12 UTC soundings across the Midwest and Great Lakes sampled very cold temperatures aloft associated with this feature (500 mb temperatures between -30 to -40 C), which will overspread the warmer waters of the Great Lakes through the afternoon and evening. While buoyancy will be minimal, lapse rates should be sufficiently steep to support occasional lightning flashes over the Lakes and along the lake shores. Isolated thunderstorms are also possible along a residual boundary off the southeastern FL coast; however, convection should remain offshore. ..Moore/Thornton.. 10/31/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1103 AM CDT Tue Oct 31 2023 Valid 311630Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible over parts of the Great Lakes and immediate vicinity, as well as off the southeastern Florida coast. ...Synopsis... Thunderstorm potential today is expected to remain largely over the Great Lakes and off the southeastern Florida Coast. A compact upper low is evident in mid-morning satellite imagery over southern WI/northern IL. This feature is expected to begin tracking to the east over the next 12 hours in tandem with the mean upper trough. 12 UTC soundings across the Midwest and Great Lakes sampled very cold temperatures aloft associated with this feature (500 mb temperatures between -30 to -40 C), which will overspread the warmer waters of the Great Lakes through the afternoon and evening. While buoyancy will be minimal, lapse rates should be sufficiently steep to support occasional lightning flashes over the Lakes and along the lake shores. Isolated thunderstorms are also possible along a residual boundary off the southeastern FL coast; however, convection should remain offshore. ..Moore/Thornton.. 10/31/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1103 AM CDT Tue Oct 31 2023 Valid 311630Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible over parts of the Great Lakes and immediate vicinity, as well as off the southeastern Florida coast. ...Synopsis... Thunderstorm potential today is expected to remain largely over the Great Lakes and off the southeastern Florida Coast. A compact upper low is evident in mid-morning satellite imagery over southern WI/northern IL. This feature is expected to begin tracking to the east over the next 12 hours in tandem with the mean upper trough. 12 UTC soundings across the Midwest and Great Lakes sampled very cold temperatures aloft associated with this feature (500 mb temperatures between -30 to -40 C), which will overspread the warmer waters of the Great Lakes through the afternoon and evening. While buoyancy will be minimal, lapse rates should be sufficiently steep to support occasional lightning flashes over the Lakes and along the lake shores. Isolated thunderstorms are also possible along a residual boundary off the southeastern FL coast; however, convection should remain offshore. ..Moore/Thornton.. 10/31/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1103 AM CDT Tue Oct 31 2023 Valid 311630Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible over parts of the Great Lakes and immediate vicinity, as well as off the southeastern Florida coast. ...Synopsis... Thunderstorm potential today is expected to remain largely over the Great Lakes and off the southeastern Florida Coast. A compact upper low is evident in mid-morning satellite imagery over southern WI/northern IL. This feature is expected to begin tracking to the east over the next 12 hours in tandem with the mean upper trough. 12 UTC soundings across the Midwest and Great Lakes sampled very cold temperatures aloft associated with this feature (500 mb temperatures between -30 to -40 C), which will overspread the warmer waters of the Great Lakes through the afternoon and evening. While buoyancy will be minimal, lapse rates should be sufficiently steep to support occasional lightning flashes over the Lakes and along the lake shores. Isolated thunderstorms are also possible along a residual boundary off the southeastern FL coast; however, convection should remain offshore. ..Moore/Thornton.. 10/31/2023 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1103 AM CDT Tue Oct 31 2023 Valid 311630Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible over parts of the Great Lakes and immediate vicinity, as well as off the southeastern Florida coast. ...Synopsis... Thunderstorm potential today is expected to remain largely over the Great Lakes and off the southeastern Florida Coast. A compact upper low is evident in mid-morning satellite imagery over southern WI/northern IL. This feature is expected to begin tracking to the east over the next 12 hours in tandem with the mean upper trough. 12 UTC soundings across the Midwest and Great Lakes sampled very cold temperatures aloft associated with this feature (500 mb temperatures between -30 to -40 C), which will overspread the warmer waters of the Great Lakes through the afternoon and evening. While buoyancy will be minimal, lapse rates should be sufficiently steep to support occasional lightning flashes over the Lakes and along the lake shores. Isolated thunderstorms are also possible along a residual boundary off the southeastern FL coast; however, convection should remain offshore. ..Moore/Thornton.. 10/31/2023 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0748 AM CDT Tue Oct 31 2023 Valid 311300Z - 011200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible over parts of the Great Lakes and immediate vicinity. ...Synopsis... In the wake of a strong surface cold front -- moving through then offshore from south FL today -- a large, continental/polar air mass will reside over much of the CONUS. Within that, a surface low is nearly stacked with a compact cyclone's midlevel center -- now apparent in upper-air analyses and satellite imagery over western WI. An accompanying mid/upper-level trough extends to Lake Superior and to near STJ. The 500-mb low is forecast to weaken through much of the period, reaching extreme northern IN by 00Z, but with a strong, positively tilted shortwave trough still attached, from Lower MI to near PAH. Overnight, the deep-layer cyclone will lose definition, with a strong, open-wave trough at 500-mb from southern ON across OH to AL by 12Z. Cold midlevel air (-30 to -35 deg C at 500 mb) is expected to move across portions of the Upper Great Lakes region (especially Lakes Michigan/Huron) today, then Lower Great Lakes tonight, in the zone of strong DCVA immediately preceding the trough aloft. As that occurs, over the lakes and areas just downwind/inland in the boundary layer, low/middle-level lapse rates will steepen rapidly, with lake moisture and thermal fluxes contributing enough theta-e for convective plumes (including snow). MLCAPE of 100-300 J/kg is possible, some of which can extend into icing layers suitable for lightning generation. Greater potential convective coverage and lightning threat are evident compared to yesterday, given the stronger deep-layer forcing and low-level lift expected. However, overall thunderstorm coverage still may be marginal for a 10%/general-thunderstorm outlook area. ..Edwards/Smith.. 10/31/2023 Read more