Severe Storms

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0318 PM CDT Wed Oct 02 2024 Valid 041200Z - 101200Z Fire weather concerns will be focused across the Pacific Northwest/Great Basin into the northern Rockies and central/northern Great Plains late this week into the weekend followed by decreasing potential for widespread fire weather concerns heading into next week. Confidence continues to increase in the arrival of an upper trough (currently noted over the northeastern Pacific in water-vapor imagery) on D3/Friday across the Pacific Northwest. This feature is forecast to quickly progress east into the northern Plains with an associated surface cyclone and attendant dry cold front. These features will support strengthening winds over regions with very dry fuels with the potential for critical fire weather conditions. Unseasonably warm and dry conditions are forecast to continue across much of the southwest to central CONUS through the middle of next week as an upper ridge builds east in the wake of the Fri/Sat system. Widespread fuel drying is anticipated during this period due to the hot/dry conditions, but relatively benign surface gradient winds should limit the potential for widespread wind-driven fire concerns. ...D3/Friday... Widespread fire weather concerns are anticipated on Friday. The greatest fire weather threat is expected to emerge across northern NV into adjacent areas of CA, OR, and ID where dry downslope flow will increase through the day with the arrival of strong westerly mid-level winds. Forecast guidance continues to trend towards stronger wind speeds with subsequent model runs, with the most recent GEFS showing 50-70% probability for sustained winds of 30 mph in the lee of the northern Sierra Nevada and southern Cascades. This trend also suggests that the areal coverage of elevated to critical fire weather conditions will be greater than previously expected, warranting not only higher risk probabilities, but an expansion of the 40% risk area into portions of southwest MT in the lee of the Bitterroot Mountains. Further east, increasing westerly flow across the WY Basin should promote elevated to critical fire weather conditions within a similar, but slightly weaker, downslope regime. Across the Plains, southerly winds are expected to strengthen across NE into the Dakotas as a surface low attendant to the approaching upper wave deepens in the lee of the Canadian Rockies. Moisture recovery is expected to be minimal in the wake of today's (Wednesday's) frontal passage across the northern Plains. RH reductions within the dry return flow regime remain somewhat uncertain, but a strong wind signal among a variety of guidance suites coupled with very dry fuels (ERCs above the 90th percentile) should promote a fire weather concern. ...D4/Saturday... A dry cold front is expected to push southeast across the northern to central Plains through the day on Saturday as the upper wave and attendant surface low progress quickly into the Great Lakes region. Sustained northwesterly winds behind the front are expected to be fairly strong, most likely between 20-30 mph, with the strongest winds expected across the Dakotas. Confidence in the fire weather potential is greatest across southern WY into western NE where the driest conditions will overlap with 20+ mph winds. Confidence in critical conditions decreases with northward extent where cooler post-frontal air may limit RH reductions. Further forecast refinements are expected, but in general this synoptic regime will likely resemble the recent frontal intrusion into the Plains on Mon, Sept 30, which resulted in widespread critical fire weather conditions. ..Moore.. 10/02/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0230 PM CDT Wed Oct 02 2024 Valid 022000Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...20Z Update... Forecast remains on track with no changes needed to the outlook. Previous forecast discussion appended below. ..Mosier.. 10/02/2024 .PREV DISCUSSION... /ISSUED 1121 AM CDT Wed Oct 02 2024/ ...Synopsis... Latest visible satellite imagery and surface observations indicate a quasi-stationary surface boundary extending across portions of northern FL. South of the boundary, diurnal heating of a moist air mass, coupled with sea breeze circulations, will support scattered diurnal thunderstorm development. Deep tropospheric moisture and steepening low-level lapse rates may support a few wet microbursts with strong-gust potential over central FL -- where any localized clustering occurs. However, weak deep-layer shear and poor midlevel lapse rates should limit the organization and intensity of storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0230 PM CDT Wed Oct 02 2024 Valid 022000Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...20Z Update... Forecast remains on track with no changes needed to the outlook. Previous forecast discussion appended below. ..Mosier.. 10/02/2024 .PREV DISCUSSION... /ISSUED 1121 AM CDT Wed Oct 02 2024/ ...Synopsis... Latest visible satellite imagery and surface observations indicate a quasi-stationary surface boundary extending across portions of northern FL. South of the boundary, diurnal heating of a moist air mass, coupled with sea breeze circulations, will support scattered diurnal thunderstorm development. Deep tropospheric moisture and steepening low-level lapse rates may support a few wet microbursts with strong-gust potential over central FL -- where any localized clustering occurs. However, weak deep-layer shear and poor midlevel lapse rates should limit the organization and intensity of storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0230 PM CDT Wed Oct 02 2024 Valid 022000Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...20Z Update... Forecast remains on track with no changes needed to the outlook. Previous forecast discussion appended below. ..Mosier.. 10/02/2024 .PREV DISCUSSION... /ISSUED 1121 AM CDT Wed Oct 02 2024/ ...Synopsis... Latest visible satellite imagery and surface observations indicate a quasi-stationary surface boundary extending across portions of northern FL. South of the boundary, diurnal heating of a moist air mass, coupled with sea breeze circulations, will support scattered diurnal thunderstorm development. Deep tropospheric moisture and steepening low-level lapse rates may support a few wet microbursts with strong-gust potential over central FL -- where any localized clustering occurs. However, weak deep-layer shear and poor midlevel lapse rates should limit the organization and intensity of storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0230 PM CDT Wed Oct 02 2024 Valid 022000Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...20Z Update... Forecast remains on track with no changes needed to the outlook. Previous forecast discussion appended below. ..Mosier.. 10/02/2024 .PREV DISCUSSION... /ISSUED 1121 AM CDT Wed Oct 02 2024/ ...Synopsis... Latest visible satellite imagery and surface observations indicate a quasi-stationary surface boundary extending across portions of northern FL. South of the boundary, diurnal heating of a moist air mass, coupled with sea breeze circulations, will support scattered diurnal thunderstorm development. Deep tropospheric moisture and steepening low-level lapse rates may support a few wet microbursts with strong-gust potential over central FL -- where any localized clustering occurs. However, weak deep-layer shear and poor midlevel lapse rates should limit the organization and intensity of storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0230 PM CDT Wed Oct 02 2024 Valid 022000Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...20Z Update... Forecast remains on track with no changes needed to the outlook. Previous forecast discussion appended below. ..Mosier.. 10/02/2024 .PREV DISCUSSION... /ISSUED 1121 AM CDT Wed Oct 02 2024/ ...Synopsis... Latest visible satellite imagery and surface observations indicate a quasi-stationary surface boundary extending across portions of northern FL. South of the boundary, diurnal heating of a moist air mass, coupled with sea breeze circulations, will support scattered diurnal thunderstorm development. Deep tropospheric moisture and steepening low-level lapse rates may support a few wet microbursts with strong-gust potential over central FL -- where any localized clustering occurs. However, weak deep-layer shear and poor midlevel lapse rates should limit the organization and intensity of storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0230 PM CDT Wed Oct 02 2024 Valid 022000Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...20Z Update... Forecast remains on track with no changes needed to the outlook. Previous forecast discussion appended below. ..Mosier.. 10/02/2024 .PREV DISCUSSION... /ISSUED 1121 AM CDT Wed Oct 02 2024/ ...Synopsis... Latest visible satellite imagery and surface observations indicate a quasi-stationary surface boundary extending across portions of northern FL. South of the boundary, diurnal heating of a moist air mass, coupled with sea breeze circulations, will support scattered diurnal thunderstorm development. Deep tropospheric moisture and steepening low-level lapse rates may support a few wet microbursts with strong-gust potential over central FL -- where any localized clustering occurs. However, weak deep-layer shear and poor midlevel lapse rates should limit the organization and intensity of storms. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0230 PM CDT Wed Oct 02 2024 Valid 022000Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected through tonight. ...20Z Update... Forecast remains on track with no changes needed to the outlook. Previous forecast discussion appended below. ..Mosier.. 10/02/2024 .PREV DISCUSSION... /ISSUED 1121 AM CDT Wed Oct 02 2024/ ...Synopsis... Latest visible satellite imagery and surface observations indicate a quasi-stationary surface boundary extending across portions of northern FL. South of the boundary, diurnal heating of a moist air mass, coupled with sea breeze circulations, will support scattered diurnal thunderstorm development. Deep tropospheric moisture and steepening low-level lapse rates may support a few wet microbursts with strong-gust potential over central FL -- where any localized clustering occurs. However, weak deep-layer shear and poor midlevel lapse rates should limit the organization and intensity of storms. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Wed Oct 02 2024 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Friday. ...Discussion... Stronger flow aloft will remain confined to the northern half of the U.S. Friday, with a couple of troughs progressing through this belt of flow -- one moving across the northwestern quarter of the country, and a second crossing the Great Lakes and eventually reaching New England. While both of these upper systems will be accompanied by a surface cold front, low-level moisture -- and thus any appreciable instability -- will remain confined to the southeastern quarter of the CONUS. Showers and a few thunderstorms will again be possible -- mainly across the Gulf Coast states. However, with flow aloft remaining weak in tandem with synoptic-scale upper ridging, severe weather is not expected. ..Goss.. 10/02/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Wed Oct 02 2024 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Friday. ...Discussion... Stronger flow aloft will remain confined to the northern half of the U.S. Friday, with a couple of troughs progressing through this belt of flow -- one moving across the northwestern quarter of the country, and a second crossing the Great Lakes and eventually reaching New England. While both of these upper systems will be accompanied by a surface cold front, low-level moisture -- and thus any appreciable instability -- will remain confined to the southeastern quarter of the CONUS. Showers and a few thunderstorms will again be possible -- mainly across the Gulf Coast states. However, with flow aloft remaining weak in tandem with synoptic-scale upper ridging, severe weather is not expected. ..Goss.. 10/02/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Wed Oct 02 2024 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Friday. ...Discussion... Stronger flow aloft will remain confined to the northern half of the U.S. Friday, with a couple of troughs progressing through this belt of flow -- one moving across the northwestern quarter of the country, and a second crossing the Great Lakes and eventually reaching New England. While both of these upper systems will be accompanied by a surface cold front, low-level moisture -- and thus any appreciable instability -- will remain confined to the southeastern quarter of the CONUS. Showers and a few thunderstorms will again be possible -- mainly across the Gulf Coast states. However, with flow aloft remaining weak in tandem with synoptic-scale upper ridging, severe weather is not expected. ..Goss.. 10/02/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Wed Oct 02 2024 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Friday. ...Discussion... Stronger flow aloft will remain confined to the northern half of the U.S. Friday, with a couple of troughs progressing through this belt of flow -- one moving across the northwestern quarter of the country, and a second crossing the Great Lakes and eventually reaching New England. While both of these upper systems will be accompanied by a surface cold front, low-level moisture -- and thus any appreciable instability -- will remain confined to the southeastern quarter of the CONUS. Showers and a few thunderstorms will again be possible -- mainly across the Gulf Coast states. However, with flow aloft remaining weak in tandem with synoptic-scale upper ridging, severe weather is not expected. ..Goss.. 10/02/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Wed Oct 02 2024 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Friday. ...Discussion... Stronger flow aloft will remain confined to the northern half of the U.S. Friday, with a couple of troughs progressing through this belt of flow -- one moving across the northwestern quarter of the country, and a second crossing the Great Lakes and eventually reaching New England. While both of these upper systems will be accompanied by a surface cold front, low-level moisture -- and thus any appreciable instability -- will remain confined to the southeastern quarter of the CONUS. Showers and a few thunderstorms will again be possible -- mainly across the Gulf Coast states. However, with flow aloft remaining weak in tandem with synoptic-scale upper ridging, severe weather is not expected. ..Goss.. 10/02/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 PM CDT Wed Oct 02 2024 Valid 041200Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Friday. ...Discussion... Stronger flow aloft will remain confined to the northern half of the U.S. Friday, with a couple of troughs progressing through this belt of flow -- one moving across the northwestern quarter of the country, and a second crossing the Great Lakes and eventually reaching New England. While both of these upper systems will be accompanied by a surface cold front, low-level moisture -- and thus any appreciable instability -- will remain confined to the southeastern quarter of the CONUS. Showers and a few thunderstorms will again be possible -- mainly across the Gulf Coast states. However, with flow aloft remaining weak in tandem with synoptic-scale upper ridging, severe weather is not expected. ..Goss.. 10/02/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0209 PM CDT Wed Oct 02 2024 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... The previous forecast remains on track with no adjustments required. Consideration was made for introducing an Elevated risk area across central NE to far western IA where winds will likely reach to near 20 mph. However, latest ensemble guidance shows somewhat poor agreement regarding post-frontal RH reductions and only 20-40% of reaching elevated wind/RH thresholds. Additionally, recent deterministic solutions have demonstrated a slight dry bias across the Plains, which introduces further uncertainty. Trends will continue to be monitored and highlights may be needed in subsequent forecasts. ..Moore.. 10/02/2024 .PREV DISCUSSION... /ISSUED 0157 AM CDT Wed Oct 02 2024/ ...Synopsis... The upper-level pattern will start to become less zonal on Thursday with a ridge traversing the Northwest and some troughing developing over the Upper Midwest. The surface pattern will be somewhat nebulous during the day Thursday with surface high pressure building into the northern Plains. Some breezy northeasterly flow may develop in portions of the Plains as this high moves south and the pressure gradient tightens. However, winds do not look that strong at this time, and the cooler airmass should lead to relative humidity mostly above 25 percent. Therefore, some localized elevated conditions are possible, but no Elevated delineation is justified at this time. ...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 0209 PM CDT Wed Oct 02 2024 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... The previous forecast remains on track with no adjustments required. Consideration was made for introducing an Elevated risk area across central NE to far western IA where winds will likely reach to near 20 mph. However, latest ensemble guidance shows somewhat poor agreement regarding post-frontal RH reductions and only 20-40% of reaching elevated wind/RH thresholds. Additionally, recent deterministic solutions have demonstrated a slight dry bias across the Plains, which introduces further uncertainty. Trends will continue to be monitored and highlights may be needed in subsequent forecasts. ..Moore.. 10/02/2024 .PREV DISCUSSION... /ISSUED 0157 AM CDT Wed Oct 02 2024/ ...Synopsis... The upper-level pattern will start to become less zonal on Thursday with a ridge traversing the Northwest and some troughing developing over the Upper Midwest. The surface pattern will be somewhat nebulous during the day Thursday with surface high pressure building into the northern Plains. Some breezy northeasterly flow may develop in portions of the Plains as this high moves south and the pressure gradient tightens. However, winds do not look that strong at this time, and the cooler airmass should lead to relative humidity mostly above 25 percent. Therefore, some localized elevated conditions are possible, but no Elevated delineation is justified at this time. ...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 0209 PM CDT Wed Oct 02 2024 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... The previous forecast remains on track with no adjustments required. Consideration was made for introducing an Elevated risk area across central NE to far western IA where winds will likely reach to near 20 mph. However, latest ensemble guidance shows somewhat poor agreement regarding post-frontal RH reductions and only 20-40% of reaching elevated wind/RH thresholds. Additionally, recent deterministic solutions have demonstrated a slight dry bias across the Plains, which introduces further uncertainty. Trends will continue to be monitored and highlights may be needed in subsequent forecasts. ..Moore.. 10/02/2024 .PREV DISCUSSION... /ISSUED 0157 AM CDT Wed Oct 02 2024/ ...Synopsis... The upper-level pattern will start to become less zonal on Thursday with a ridge traversing the Northwest and some troughing developing over the Upper Midwest. The surface pattern will be somewhat nebulous during the day Thursday with surface high pressure building into the northern Plains. Some breezy northeasterly flow may develop in portions of the Plains as this high moves south and the pressure gradient tightens. However, winds do not look that strong at this time, and the cooler airmass should lead to relative humidity mostly above 25 percent. Therefore, some localized elevated conditions are possible, but no Elevated delineation is justified at this time. ...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 0209 PM CDT Wed Oct 02 2024 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... The previous forecast remains on track with no adjustments required. Consideration was made for introducing an Elevated risk area across central NE to far western IA where winds will likely reach to near 20 mph. However, latest ensemble guidance shows somewhat poor agreement regarding post-frontal RH reductions and only 20-40% of reaching elevated wind/RH thresholds. Additionally, recent deterministic solutions have demonstrated a slight dry bias across the Plains, which introduces further uncertainty. Trends will continue to be monitored and highlights may be needed in subsequent forecasts. ..Moore.. 10/02/2024 .PREV DISCUSSION... /ISSUED 0157 AM CDT Wed Oct 02 2024/ ...Synopsis... The upper-level pattern will start to become less zonal on Thursday with a ridge traversing the Northwest and some troughing developing over the Upper Midwest. The surface pattern will be somewhat nebulous during the day Thursday with surface high pressure building into the northern Plains. Some breezy northeasterly flow may develop in portions of the Plains as this high moves south and the pressure gradient tightens. However, winds do not look that strong at this time, and the cooler airmass should lead to relative humidity mostly above 25 percent. Therefore, some localized elevated conditions are possible, but no Elevated delineation is justified at this time. ...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 0209 PM CDT Wed Oct 02 2024 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... The previous forecast remains on track with no adjustments required. Consideration was made for introducing an Elevated risk area across central NE to far western IA where winds will likely reach to near 20 mph. However, latest ensemble guidance shows somewhat poor agreement regarding post-frontal RH reductions and only 20-40% of reaching elevated wind/RH thresholds. Additionally, recent deterministic solutions have demonstrated a slight dry bias across the Plains, which introduces further uncertainty. Trends will continue to be monitored and highlights may be needed in subsequent forecasts. ..Moore.. 10/02/2024 .PREV DISCUSSION... /ISSUED 0157 AM CDT Wed Oct 02 2024/ ...Synopsis... The upper-level pattern will start to become less zonal on Thursday with a ridge traversing the Northwest and some troughing developing over the Upper Midwest. The surface pattern will be somewhat nebulous during the day Thursday with surface high pressure building into the northern Plains. Some breezy northeasterly flow may develop in portions of the Plains as this high moves south and the pressure gradient tightens. However, winds do not look that strong at this time, and the cooler airmass should lead to relative humidity mostly above 25 percent. Therefore, some localized elevated conditions are possible, but no Elevated delineation is justified at this time. ...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 0209 PM CDT Wed Oct 02 2024 Valid 031200Z - 041200Z ...NO CRITICAL AREAS... The previous forecast remains on track with no adjustments required. Consideration was made for introducing an Elevated risk area across central NE to far western IA where winds will likely reach to near 20 mph. However, latest ensemble guidance shows somewhat poor agreement regarding post-frontal RH reductions and only 20-40% of reaching elevated wind/RH thresholds. Additionally, recent deterministic solutions have demonstrated a slight dry bias across the Plains, which introduces further uncertainty. Trends will continue to be monitored and highlights may be needed in subsequent forecasts. ..Moore.. 10/02/2024 .PREV DISCUSSION... /ISSUED 0157 AM CDT Wed Oct 02 2024/ ...Synopsis... The upper-level pattern will start to become less zonal on Thursday with a ridge traversing the Northwest and some troughing developing over the Upper Midwest. The surface pattern will be somewhat nebulous during the day Thursday with surface high pressure building into the northern Plains. Some breezy northeasterly flow may develop in portions of the Plains as this high moves south and the pressure gradient tightens. However, winds do not look that strong at this time, and the cooler airmass should lead to relative humidity mostly above 25 percent. Therefore, some localized elevated conditions are possible, but no Elevated delineation is justified at this time. ...Please see www.spc.noaa.gov/fire for graphic product... Read more