Severe Storms

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Mon Sep 02 2024 Valid 021200Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL TO WESTERN IDAHO AND ADJACENT PORTIONS OF NEVADA AND OREGON... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the Pacific Northwest may be capable of strong to severe wind gusts this afternoon and evening. ...Synopsis... Recent water-vapor imagery depicts a dominant upper ridge centered over the central CONUS. Flanking the ridge is a departing upper trough across the lower Great Lakes/Northeast and a more compact shortwave trough off the northern California coast. This upper-air regime will largely remain intact for the next 24 hours as the Northeast upper wave continues to move into the western Atlantic and the CA shortwave migrates towards the northern Rockies. At the surface, a slowing cold front draped from the Northeast into the southern Plains will continue to meander south through the day as a surface high builds over the Midwest. Isolated to scattered thunderstorms will be possible along this front and in the vicinity of a weak mid-level disturbance over western TX; however, weak flow aloft will hinder the potential for organized convection. Across the West, thunderstorms, including a few strong to severe storms, are expected ahead of the upper trough as it moves onshore over the next 24 hours. ...Nevada into eastern Oregon and Idaho... A modest plume of monsoonal moisture has been tracked from southern AZ into northern NV/eastern OR over the past few days, and has resulted in multiple rounds of thunderstorms across the Great Basin despite very limited low-level moisture and only modestly cool mid-level temperatures. These conditions were well-sampled by the 00 UTC MFR sounding, which depicts around 250 J/kg MLCAPE atop a very deep, dry boundary layer. This profile will be typical this afternoon across the region as ascent associated with the approaching wave overspreads the northern Great Basin/Pacific Northwest. Despite minimal buoyancy, LCL heights between 3-4 km will foster ample evaporative cooling of convective downdrafts that will support strong downburst winds. Increasing flow throughout the column will improve wind shear within the CAPE-bearing layer, promoting better storm longevity and organization (and hence a higher potential for producing strong/severe wind gusts) compared to previous days. Recent CAM solutions also hint at this potential with several HREF members showing isolated swaths of severe winds across northern NV into central and western ID and eastern OR. ..Moore/Kerr.. 09/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Mon Sep 02 2024 Valid 021200Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL TO WESTERN IDAHO AND ADJACENT PORTIONS OF NEVADA AND OREGON... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the Pacific Northwest may be capable of strong to severe wind gusts this afternoon and evening. ...Synopsis... Recent water-vapor imagery depicts a dominant upper ridge centered over the central CONUS. Flanking the ridge is a departing upper trough across the lower Great Lakes/Northeast and a more compact shortwave trough off the northern California coast. This upper-air regime will largely remain intact for the next 24 hours as the Northeast upper wave continues to move into the western Atlantic and the CA shortwave migrates towards the northern Rockies. At the surface, a slowing cold front draped from the Northeast into the southern Plains will continue to meander south through the day as a surface high builds over the Midwest. Isolated to scattered thunderstorms will be possible along this front and in the vicinity of a weak mid-level disturbance over western TX; however, weak flow aloft will hinder the potential for organized convection. Across the West, thunderstorms, including a few strong to severe storms, are expected ahead of the upper trough as it moves onshore over the next 24 hours. ...Nevada into eastern Oregon and Idaho... A modest plume of monsoonal moisture has been tracked from southern AZ into northern NV/eastern OR over the past few days, and has resulted in multiple rounds of thunderstorms across the Great Basin despite very limited low-level moisture and only modestly cool mid-level temperatures. These conditions were well-sampled by the 00 UTC MFR sounding, which depicts around 250 J/kg MLCAPE atop a very deep, dry boundary layer. This profile will be typical this afternoon across the region as ascent associated with the approaching wave overspreads the northern Great Basin/Pacific Northwest. Despite minimal buoyancy, LCL heights between 3-4 km will foster ample evaporative cooling of convective downdrafts that will support strong downburst winds. Increasing flow throughout the column will improve wind shear within the CAPE-bearing layer, promoting better storm longevity and organization (and hence a higher potential for producing strong/severe wind gusts) compared to previous days. Recent CAM solutions also hint at this potential with several HREF members showing isolated swaths of severe winds across northern NV into central and western ID and eastern OR. ..Moore/Kerr.. 09/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Mon Sep 02 2024 Valid 021200Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL TO WESTERN IDAHO AND ADJACENT PORTIONS OF NEVADA AND OREGON... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the Pacific Northwest may be capable of strong to severe wind gusts this afternoon and evening. ...Synopsis... Recent water-vapor imagery depicts a dominant upper ridge centered over the central CONUS. Flanking the ridge is a departing upper trough across the lower Great Lakes/Northeast and a more compact shortwave trough off the northern California coast. This upper-air regime will largely remain intact for the next 24 hours as the Northeast upper wave continues to move into the western Atlantic and the CA shortwave migrates towards the northern Rockies. At the surface, a slowing cold front draped from the Northeast into the southern Plains will continue to meander south through the day as a surface high builds over the Midwest. Isolated to scattered thunderstorms will be possible along this front and in the vicinity of a weak mid-level disturbance over western TX; however, weak flow aloft will hinder the potential for organized convection. Across the West, thunderstorms, including a few strong to severe storms, are expected ahead of the upper trough as it moves onshore over the next 24 hours. ...Nevada into eastern Oregon and Idaho... A modest plume of monsoonal moisture has been tracked from southern AZ into northern NV/eastern OR over the past few days, and has resulted in multiple rounds of thunderstorms across the Great Basin despite very limited low-level moisture and only modestly cool mid-level temperatures. These conditions were well-sampled by the 00 UTC MFR sounding, which depicts around 250 J/kg MLCAPE atop a very deep, dry boundary layer. This profile will be typical this afternoon across the region as ascent associated with the approaching wave overspreads the northern Great Basin/Pacific Northwest. Despite minimal buoyancy, LCL heights between 3-4 km will foster ample evaporative cooling of convective downdrafts that will support strong downburst winds. Increasing flow throughout the column will improve wind shear within the CAPE-bearing layer, promoting better storm longevity and organization (and hence a higher potential for producing strong/severe wind gusts) compared to previous days. Recent CAM solutions also hint at this potential with several HREF members showing isolated swaths of severe winds across northern NV into central and western ID and eastern OR. ..Moore/Kerr.. 09/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Mon Sep 02 2024 Valid 021200Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL TO WESTERN IDAHO AND ADJACENT PORTIONS OF NEVADA AND OREGON... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the Pacific Northwest may be capable of strong to severe wind gusts this afternoon and evening. ...Synopsis... Recent water-vapor imagery depicts a dominant upper ridge centered over the central CONUS. Flanking the ridge is a departing upper trough across the lower Great Lakes/Northeast and a more compact shortwave trough off the northern California coast. This upper-air regime will largely remain intact for the next 24 hours as the Northeast upper wave continues to move into the western Atlantic and the CA shortwave migrates towards the northern Rockies. At the surface, a slowing cold front draped from the Northeast into the southern Plains will continue to meander south through the day as a surface high builds over the Midwest. Isolated to scattered thunderstorms will be possible along this front and in the vicinity of a weak mid-level disturbance over western TX; however, weak flow aloft will hinder the potential for organized convection. Across the West, thunderstorms, including a few strong to severe storms, are expected ahead of the upper trough as it moves onshore over the next 24 hours. ...Nevada into eastern Oregon and Idaho... A modest plume of monsoonal moisture has been tracked from southern AZ into northern NV/eastern OR over the past few days, and has resulted in multiple rounds of thunderstorms across the Great Basin despite very limited low-level moisture and only modestly cool mid-level temperatures. These conditions were well-sampled by the 00 UTC MFR sounding, which depicts around 250 J/kg MLCAPE atop a very deep, dry boundary layer. This profile will be typical this afternoon across the region as ascent associated with the approaching wave overspreads the northern Great Basin/Pacific Northwest. Despite minimal buoyancy, LCL heights between 3-4 km will foster ample evaporative cooling of convective downdrafts that will support strong downburst winds. Increasing flow throughout the column will improve wind shear within the CAPE-bearing layer, promoting better storm longevity and organization (and hence a higher potential for producing strong/severe wind gusts) compared to previous days. Recent CAM solutions also hint at this potential with several HREF members showing isolated swaths of severe winds across northern NV into central and western ID and eastern OR. ..Moore/Kerr.. 09/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Mon Sep 02 2024 Valid 021200Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL TO WESTERN IDAHO AND ADJACENT PORTIONS OF NEVADA AND OREGON... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the Pacific Northwest may be capable of strong to severe wind gusts this afternoon and evening. ...Synopsis... Recent water-vapor imagery depicts a dominant upper ridge centered over the central CONUS. Flanking the ridge is a departing upper trough across the lower Great Lakes/Northeast and a more compact shortwave trough off the northern California coast. This upper-air regime will largely remain intact for the next 24 hours as the Northeast upper wave continues to move into the western Atlantic and the CA shortwave migrates towards the northern Rockies. At the surface, a slowing cold front draped from the Northeast into the southern Plains will continue to meander south through the day as a surface high builds over the Midwest. Isolated to scattered thunderstorms will be possible along this front and in the vicinity of a weak mid-level disturbance over western TX; however, weak flow aloft will hinder the potential for organized convection. Across the West, thunderstorms, including a few strong to severe storms, are expected ahead of the upper trough as it moves onshore over the next 24 hours. ...Nevada into eastern Oregon and Idaho... A modest plume of monsoonal moisture has been tracked from southern AZ into northern NV/eastern OR over the past few days, and has resulted in multiple rounds of thunderstorms across the Great Basin despite very limited low-level moisture and only modestly cool mid-level temperatures. These conditions were well-sampled by the 00 UTC MFR sounding, which depicts around 250 J/kg MLCAPE atop a very deep, dry boundary layer. This profile will be typical this afternoon across the region as ascent associated with the approaching wave overspreads the northern Great Basin/Pacific Northwest. Despite minimal buoyancy, LCL heights between 3-4 km will foster ample evaporative cooling of convective downdrafts that will support strong downburst winds. Increasing flow throughout the column will improve wind shear within the CAPE-bearing layer, promoting better storm longevity and organization (and hence a higher potential for producing strong/severe wind gusts) compared to previous days. Recent CAM solutions also hint at this potential with several HREF members showing isolated swaths of severe winds across northern NV into central and western ID and eastern OR. ..Moore/Kerr.. 09/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1241 AM CDT Mon Sep 02 2024 Valid 021200Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL TO WESTERN IDAHO AND ADJACENT PORTIONS OF NEVADA AND OREGON... ...SUMMARY... Isolated to scattered thunderstorms across the northern Great Basin and parts of the Pacific Northwest may be capable of strong to severe wind gusts this afternoon and evening. ...Synopsis... Recent water-vapor imagery depicts a dominant upper ridge centered over the central CONUS. Flanking the ridge is a departing upper trough across the lower Great Lakes/Northeast and a more compact shortwave trough off the northern California coast. This upper-air regime will largely remain intact for the next 24 hours as the Northeast upper wave continues to move into the western Atlantic and the CA shortwave migrates towards the northern Rockies. At the surface, a slowing cold front draped from the Northeast into the southern Plains will continue to meander south through the day as a surface high builds over the Midwest. Isolated to scattered thunderstorms will be possible along this front and in the vicinity of a weak mid-level disturbance over western TX; however, weak flow aloft will hinder the potential for organized convection. Across the West, thunderstorms, including a few strong to severe storms, are expected ahead of the upper trough as it moves onshore over the next 24 hours. ...Nevada into eastern Oregon and Idaho... A modest plume of monsoonal moisture has been tracked from southern AZ into northern NV/eastern OR over the past few days, and has resulted in multiple rounds of thunderstorms across the Great Basin despite very limited low-level moisture and only modestly cool mid-level temperatures. These conditions were well-sampled by the 00 UTC MFR sounding, which depicts around 250 J/kg MLCAPE atop a very deep, dry boundary layer. This profile will be typical this afternoon across the region as ascent associated with the approaching wave overspreads the northern Great Basin/Pacific Northwest. Despite minimal buoyancy, LCL heights between 3-4 km will foster ample evaporative cooling of convective downdrafts that will support strong downburst winds. Increasing flow throughout the column will improve wind shear within the CAPE-bearing layer, promoting better storm longevity and organization (and hence a higher potential for producing strong/severe wind gusts) compared to previous days. Recent CAM solutions also hint at this potential with several HREF members showing isolated swaths of severe winds across northern NV into central and western ID and eastern OR. ..Moore/Kerr.. 09/02/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 PM CDT Sun Sep 01 2024 Valid 020100Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated to scattered thunderstorms will continue into the late evening and overnight hours from the Mid-Atlantic region into the southern CONUS, Four Corners region, and Pacific Northwest. ...Summary... Isolated to scattered thunderstorms are expected to persist into the early morning hours across parts of the Mid-Atlantic, but the overall severe threat appears sufficiently low to remove risk probabilities. ...Mid-Atlantic... Thunderstorms across the Mid-Atlantic region have shown signs of steady weakening over the past hour based on regional reflectivity imagery, MRMS echo-top heights, and cloud-top temperatures. 00 UTC soundings along the East Coast, and downstream from ongoing multicell clusters, sampled around 500-1000 J/kg MLCAPE with around 20 knots of mid-level flow. A sporadic strong updraft or two will remain possible this evening along the outflow boundaries of ongoing convection given these environmental conditions. However, the onset of nocturnal cooling will continue to modulate mixed-layer buoyancy (with an attendance increase in inhibition), which should maintain the overall weakening trend. Latest CAM solutions support this scenario with increasingly sparse thunderstorm coverage heading into the early morning hours. Consequently, the overall severe potential appears sufficiently low to warrant removing risk probabilities. ..Moore.. 09/02/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 PM CDT Sun Sep 01 2024 Valid 020100Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated to scattered thunderstorms will continue into the late evening and overnight hours from the Mid-Atlantic region into the southern CONUS, Four Corners region, and Pacific Northwest. ...Summary... Isolated to scattered thunderstorms are expected to persist into the early morning hours across parts of the Mid-Atlantic, but the overall severe threat appears sufficiently low to remove risk probabilities. ...Mid-Atlantic... Thunderstorms across the Mid-Atlantic region have shown signs of steady weakening over the past hour based on regional reflectivity imagery, MRMS echo-top heights, and cloud-top temperatures. 00 UTC soundings along the East Coast, and downstream from ongoing multicell clusters, sampled around 500-1000 J/kg MLCAPE with around 20 knots of mid-level flow. A sporadic strong updraft or two will remain possible this evening along the outflow boundaries of ongoing convection given these environmental conditions. However, the onset of nocturnal cooling will continue to modulate mixed-layer buoyancy (with an attendance increase in inhibition), which should maintain the overall weakening trend. Latest CAM solutions support this scenario with increasingly sparse thunderstorm coverage heading into the early morning hours. Consequently, the overall severe potential appears sufficiently low to warrant removing risk probabilities. ..Moore.. 09/02/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 PM CDT Sun Sep 01 2024 Valid 020100Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated to scattered thunderstorms will continue into the late evening and overnight hours from the Mid-Atlantic region into the southern CONUS, Four Corners region, and Pacific Northwest. ...Summary... Isolated to scattered thunderstorms are expected to persist into the early morning hours across parts of the Mid-Atlantic, but the overall severe threat appears sufficiently low to remove risk probabilities. ...Mid-Atlantic... Thunderstorms across the Mid-Atlantic region have shown signs of steady weakening over the past hour based on regional reflectivity imagery, MRMS echo-top heights, and cloud-top temperatures. 00 UTC soundings along the East Coast, and downstream from ongoing multicell clusters, sampled around 500-1000 J/kg MLCAPE with around 20 knots of mid-level flow. A sporadic strong updraft or two will remain possible this evening along the outflow boundaries of ongoing convection given these environmental conditions. However, the onset of nocturnal cooling will continue to modulate mixed-layer buoyancy (with an attendance increase in inhibition), which should maintain the overall weakening trend. Latest CAM solutions support this scenario with increasingly sparse thunderstorm coverage heading into the early morning hours. Consequently, the overall severe potential appears sufficiently low to warrant removing risk probabilities. ..Moore.. 09/02/2024 Read more

No Mesoscale Discussions are in effect as of Sun Sep 1 22:16:01 UTC 2024.

No watches are valid as of Sun Sep 1 22:16:01 UTC 2024.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0416 PM CDT Sun Sep 01 2024 Valid 031200Z - 091200Z A midlevel trough and accompanying midlevel speed max will move across the northern Rockies on D3/Tue, bringing an increase in surface winds across portions of Idaho and Wyoming. High pressure will build in across the western US D4/Wednesday through D8/Saturday, with a warming and drying trend. As this occurs, monsoonal moisture will gradually shift southward with drying conditions extending into the desert Southwest through D7/Friday. Winds will remain mostly light where fuels are dry, keeping fire weather concerns low. ...Dry/Windy... As a midlevel speed max moves across Idaho into Montana D3/Tuesday, Critical conditions will be likely in the Snake River Plain, where relative humidity in the teens and sustained westerly winds around 20 mph will overlap critically dry fuels. Across eastern Wyoming, Elevated to Critical fire weather conditions will be possible as a surface low deepens and westerly gradients increase across the Dakotas. Downslope warming and drying will result in relative humidity reductions into the upper teens to 20s amid sustained winds at 15-20 mph. A 40 percent delineation was added with this outlook. ...Isolated Dry Thunderstorms... Thunderstorm potential will continue across the northern Rockies on D3/Tuesday, though gradually increasing moisture and precipitation cast uncertainty on the overall fire-weather risk, which precludes Isolated Dry Thunderstorm probabilities. ..Thornton.. 09/01/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0416 PM CDT Sun Sep 01 2024 Valid 031200Z - 091200Z A midlevel trough and accompanying midlevel speed max will move across the northern Rockies on D3/Tue, bringing an increase in surface winds across portions of Idaho and Wyoming. High pressure will build in across the western US D4/Wednesday through D8/Saturday, with a warming and drying trend. As this occurs, monsoonal moisture will gradually shift southward with drying conditions extending into the desert Southwest through D7/Friday. Winds will remain mostly light where fuels are dry, keeping fire weather concerns low. ...Dry/Windy... As a midlevel speed max moves across Idaho into Montana D3/Tuesday, Critical conditions will be likely in the Snake River Plain, where relative humidity in the teens and sustained westerly winds around 20 mph will overlap critically dry fuels. Across eastern Wyoming, Elevated to Critical fire weather conditions will be possible as a surface low deepens and westerly gradients increase across the Dakotas. Downslope warming and drying will result in relative humidity reductions into the upper teens to 20s amid sustained winds at 15-20 mph. A 40 percent delineation was added with this outlook. ...Isolated Dry Thunderstorms... Thunderstorm potential will continue across the northern Rockies on D3/Tuesday, though gradually increasing moisture and precipitation cast uncertainty on the overall fire-weather risk, which precludes Isolated Dry Thunderstorm probabilities. ..Thornton.. 09/01/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0416 PM CDT Sun Sep 01 2024 Valid 031200Z - 091200Z A midlevel trough and accompanying midlevel speed max will move across the northern Rockies on D3/Tue, bringing an increase in surface winds across portions of Idaho and Wyoming. High pressure will build in across the western US D4/Wednesday through D8/Saturday, with a warming and drying trend. As this occurs, monsoonal moisture will gradually shift southward with drying conditions extending into the desert Southwest through D7/Friday. Winds will remain mostly light where fuels are dry, keeping fire weather concerns low. ...Dry/Windy... As a midlevel speed max moves across Idaho into Montana D3/Tuesday, Critical conditions will be likely in the Snake River Plain, where relative humidity in the teens and sustained westerly winds around 20 mph will overlap critically dry fuels. Across eastern Wyoming, Elevated to Critical fire weather conditions will be possible as a surface low deepens and westerly gradients increase across the Dakotas. Downslope warming and drying will result in relative humidity reductions into the upper teens to 20s amid sustained winds at 15-20 mph. A 40 percent delineation was added with this outlook. ...Isolated Dry Thunderstorms... Thunderstorm potential will continue across the northern Rockies on D3/Tuesday, though gradually increasing moisture and precipitation cast uncertainty on the overall fire-weather risk, which precludes Isolated Dry Thunderstorm probabilities. ..Thornton.. 09/01/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0416 PM CDT Sun Sep 01 2024 Valid 031200Z - 091200Z A midlevel trough and accompanying midlevel speed max will move across the northern Rockies on D3/Tue, bringing an increase in surface winds across portions of Idaho and Wyoming. High pressure will build in across the western US D4/Wednesday through D8/Saturday, with a warming and drying trend. As this occurs, monsoonal moisture will gradually shift southward with drying conditions extending into the desert Southwest through D7/Friday. Winds will remain mostly light where fuels are dry, keeping fire weather concerns low. ...Dry/Windy... As a midlevel speed max moves across Idaho into Montana D3/Tuesday, Critical conditions will be likely in the Snake River Plain, where relative humidity in the teens and sustained westerly winds around 20 mph will overlap critically dry fuels. Across eastern Wyoming, Elevated to Critical fire weather conditions will be possible as a surface low deepens and westerly gradients increase across the Dakotas. Downslope warming and drying will result in relative humidity reductions into the upper teens to 20s amid sustained winds at 15-20 mph. A 40 percent delineation was added with this outlook. ...Isolated Dry Thunderstorms... Thunderstorm potential will continue across the northern Rockies on D3/Tuesday, though gradually increasing moisture and precipitation cast uncertainty on the overall fire-weather risk, which precludes Isolated Dry Thunderstorm probabilities. ..Thornton.. 09/01/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0416 PM CDT Sun Sep 01 2024 Valid 031200Z - 091200Z A midlevel trough and accompanying midlevel speed max will move across the northern Rockies on D3/Tue, bringing an increase in surface winds across portions of Idaho and Wyoming. High pressure will build in across the western US D4/Wednesday through D8/Saturday, with a warming and drying trend. As this occurs, monsoonal moisture will gradually shift southward with drying conditions extending into the desert Southwest through D7/Friday. Winds will remain mostly light where fuels are dry, keeping fire weather concerns low. ...Dry/Windy... As a midlevel speed max moves across Idaho into Montana D3/Tuesday, Critical conditions will be likely in the Snake River Plain, where relative humidity in the teens and sustained westerly winds around 20 mph will overlap critically dry fuels. Across eastern Wyoming, Elevated to Critical fire weather conditions will be possible as a surface low deepens and westerly gradients increase across the Dakotas. Downslope warming and drying will result in relative humidity reductions into the upper teens to 20s amid sustained winds at 15-20 mph. A 40 percent delineation was added with this outlook. ...Isolated Dry Thunderstorms... Thunderstorm potential will continue across the northern Rockies on D3/Tuesday, though gradually increasing moisture and precipitation cast uncertainty on the overall fire-weather risk, which precludes Isolated Dry Thunderstorm probabilities. ..Thornton.. 09/01/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0416 PM CDT Sun Sep 01 2024 Valid 031200Z - 091200Z A midlevel trough and accompanying midlevel speed max will move across the northern Rockies on D3/Tue, bringing an increase in surface winds across portions of Idaho and Wyoming. High pressure will build in across the western US D4/Wednesday through D8/Saturday, with a warming and drying trend. As this occurs, monsoonal moisture will gradually shift southward with drying conditions extending into the desert Southwest through D7/Friday. Winds will remain mostly light where fuels are dry, keeping fire weather concerns low. ...Dry/Windy... As a midlevel speed max moves across Idaho into Montana D3/Tuesday, Critical conditions will be likely in the Snake River Plain, where relative humidity in the teens and sustained westerly winds around 20 mph will overlap critically dry fuels. Across eastern Wyoming, Elevated to Critical fire weather conditions will be possible as a surface low deepens and westerly gradients increase across the Dakotas. Downslope warming and drying will result in relative humidity reductions into the upper teens to 20s amid sustained winds at 15-20 mph. A 40 percent delineation was added with this outlook. ...Isolated Dry Thunderstorms... Thunderstorm potential will continue across the northern Rockies on D3/Tuesday, though gradually increasing moisture and precipitation cast uncertainty on the overall fire-weather risk, which precludes Isolated Dry Thunderstorm probabilities. ..Thornton.. 09/01/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0416 PM CDT Sun Sep 01 2024 Valid 031200Z - 091200Z A midlevel trough and accompanying midlevel speed max will move across the northern Rockies on D3/Tue, bringing an increase in surface winds across portions of Idaho and Wyoming. High pressure will build in across the western US D4/Wednesday through D8/Saturday, with a warming and drying trend. As this occurs, monsoonal moisture will gradually shift southward with drying conditions extending into the desert Southwest through D7/Friday. Winds will remain mostly light where fuels are dry, keeping fire weather concerns low. ...Dry/Windy... As a midlevel speed max moves across Idaho into Montana D3/Tuesday, Critical conditions will be likely in the Snake River Plain, where relative humidity in the teens and sustained westerly winds around 20 mph will overlap critically dry fuels. Across eastern Wyoming, Elevated to Critical fire weather conditions will be possible as a surface low deepens and westerly gradients increase across the Dakotas. Downslope warming and drying will result in relative humidity reductions into the upper teens to 20s amid sustained winds at 15-20 mph. A 40 percent delineation was added with this outlook. ...Isolated Dry Thunderstorms... Thunderstorm potential will continue across the northern Rockies on D3/Tuesday, though gradually increasing moisture and precipitation cast uncertainty on the overall fire-weather risk, which precludes Isolated Dry Thunderstorm probabilities. ..Thornton.. 09/01/2024 ...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 0255 PM CDT Sun Sep 01 2024 Valid 012000Z - 021200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF UPSTATE NEW YORK AND SOUTHERN NEW ENGLAND INTO THE CAROLINAS AND SOUTHERN APPALACHIANS... ...SUMMARY... Strong to severe thunderstorms capable of producing isolated damaging winds may still occur this afternoon across parts of the southern Appalachians into the Mid-Atlantic and southern New England. ...20Z Update... The previous forecast remains on track, with only slight changes made to the thunder line to reflect the latest guidance consensus and observations. ..Squitieri.. 09/01/2024 .PREV DISCUSSION... /ISSUED 1125 AM CDT Sun Sep 01 2024/ ...Southern Appalachians into the Mid-Atlantic and Southern New England... Thunderstorms should gradually increase in coverage this afternoon along/south of a diffuse front that extends from the Mid-South/lower OH Valley into the Mid-Atlantic. Late morning visible satellite imagery shows substantial cloud cover in the vicinity of the boundary. Nevertheless, daytime heating of a moist low-level air mass should allow at least weak/pockets of moderate instability to develop by early to mid afternoon along and south/east of the front. Modest ascent with an upper trough over eastern Canada and adjacent Great Lakes/Northeast U.S., in combination with orographic ascent, will likely contribute to thunderstorm development through the afternoon and early evening. Mid-level flow and related deep-layer shear will remain fairly modest, especially with southward extent across the Mid-Atlantic into the Carolinas and southern Appalachians. Mid-level flow should still prove sufficient to support modest thunderstorm organization. Multiple loosely organized multicell clusters may eventually develop and consolidate by late afternoon and early evening, posing some threat for isolated strong to damaging winds while moving generally eastward. The greatest concentration of thunderstorms should exist across parts of southern VA into NC and upstate SC where greater instability (MLCAPE on the order of 2000-2500 J/kg) is forecast this afternoon. ...Western/Northern New York into Northern New England... The upper-level trough and associated surface cold front will move east today across Ontario/Quebec provinces and Northeast U.S., with weak surface-based instability possibly developing in advance of the front. This may result in a narrow, low-topped line of convection (possibly with little lightning) moving east and accompanied by some risk for strong/locally damaging gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Sun Sep 01 2024 Valid 012000Z - 021200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF UPSTATE NEW YORK AND SOUTHERN NEW ENGLAND INTO THE CAROLINAS AND SOUTHERN APPALACHIANS... ...SUMMARY... Strong to severe thunderstorms capable of producing isolated damaging winds may still occur this afternoon across parts of the southern Appalachians into the Mid-Atlantic and southern New England. ...20Z Update... The previous forecast remains on track, with only slight changes made to the thunder line to reflect the latest guidance consensus and observations. ..Squitieri.. 09/01/2024 .PREV DISCUSSION... /ISSUED 1125 AM CDT Sun Sep 01 2024/ ...Southern Appalachians into the Mid-Atlantic and Southern New England... Thunderstorms should gradually increase in coverage this afternoon along/south of a diffuse front that extends from the Mid-South/lower OH Valley into the Mid-Atlantic. Late morning visible satellite imagery shows substantial cloud cover in the vicinity of the boundary. Nevertheless, daytime heating of a moist low-level air mass should allow at least weak/pockets of moderate instability to develop by early to mid afternoon along and south/east of the front. Modest ascent with an upper trough over eastern Canada and adjacent Great Lakes/Northeast U.S., in combination with orographic ascent, will likely contribute to thunderstorm development through the afternoon and early evening. Mid-level flow and related deep-layer shear will remain fairly modest, especially with southward extent across the Mid-Atlantic into the Carolinas and southern Appalachians. Mid-level flow should still prove sufficient to support modest thunderstorm organization. Multiple loosely organized multicell clusters may eventually develop and consolidate by late afternoon and early evening, posing some threat for isolated strong to damaging winds while moving generally eastward. The greatest concentration of thunderstorms should exist across parts of southern VA into NC and upstate SC where greater instability (MLCAPE on the order of 2000-2500 J/kg) is forecast this afternoon. ...Western/Northern New York into Northern New England... The upper-level trough and associated surface cold front will move east today across Ontario/Quebec provinces and Northeast U.S., with weak surface-based instability possibly developing in advance of the front. This may result in a narrow, low-topped line of convection (possibly with little lightning) moving east and accompanied by some risk for strong/locally damaging gusts. Read more