Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0259 PM CDT Tue Sep 09 2025 Valid 101200Z - 111200Z ...Washington State... An upper-level trough moving into the western U.S. will support another round of dry thunderstorms through tonight into the early Day 2 period. Numerous new fire ignitions from overnight thunderstorms occurred this morning across central WA. Cloud to ground lightning and minimal rainfall outside thunderstorm rain cores will continue to present an ignition threat in heavier, drought stressed fuels across the WA Cascades, and north central WA, particularly in the morning hours. Thunderstorm development will shift primarily to higher terrain by Wednesday afternoon across central WA. ...Eastern Great Basin and Western Utah... A robust mid-level jet (50-60 knots) rounding the base of the upper-level low over northern California combined with deep, well-mixed boundary layer will support breezy south-southwest surface winds of 15-25 mph Wednesday afternoon. The gusty winds along with relative humidity in the 15-20% range will result in elevated to locally critical fire weather conditions across east-central NV into western UT. Although fuels are only marginally dry, the stronger winds and low RH could contribute to wildfire spread. ..Williams.. 09/09/2025 .PREV DISCUSSION... /ISSUED 1255 AM CDT Tue Sep 09 2025/ ...Synopsis... For Wednesday, not much change in the upper-level pattern is expected from Tuesday. The upper-level trough in the West will shift into more of the Great Basin and the mid-level jet will extend farther northward. Showers and thunderstorms remain possible in the Northwest and northern Rockies. ...Eastern Great Basin into Idaho/Wyoming... Dry and breezy conditions appear likely during the afternoon. Winds of 15-25 mph will be possible along with RH of 15-20%. Even with these elevated to locally critical meteorological conditions, fuels are not likely to become receptive enough to support more than a locally elevated risk. ...Northwest/northern Rockies... While thunderstorms will be possible in association with the upper low, recent precipitation and substantial cloud cover should generally limit the overall risk for lightning ignitions. A continued downward trend in fuel receptiveness is expected Wednesday. Highlights do not appear warranted 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 0259 PM CDT Tue Sep 09 2025 Valid 101200Z - 111200Z ...Washington State... An upper-level trough moving into the western U.S. will support another round of dry thunderstorms through tonight into the early Day 2 period. Numerous new fire ignitions from overnight thunderstorms occurred this morning across central WA. Cloud to ground lightning and minimal rainfall outside thunderstorm rain cores will continue to present an ignition threat in heavier, drought stressed fuels across the WA Cascades, and north central WA, particularly in the morning hours. Thunderstorm development will shift primarily to higher terrain by Wednesday afternoon across central WA. ...Eastern Great Basin and Western Utah... A robust mid-level jet (50-60 knots) rounding the base of the upper-level low over northern California combined with deep, well-mixed boundary layer will support breezy south-southwest surface winds of 15-25 mph Wednesday afternoon. The gusty winds along with relative humidity in the 15-20% range will result in elevated to locally critical fire weather conditions across east-central NV into western UT. Although fuels are only marginally dry, the stronger winds and low RH could contribute to wildfire spread. ..Williams.. 09/09/2025 .PREV DISCUSSION... /ISSUED 1255 AM CDT Tue Sep 09 2025/ ...Synopsis... For Wednesday, not much change in the upper-level pattern is expected from Tuesday. The upper-level trough in the West will shift into more of the Great Basin and the mid-level jet will extend farther northward. Showers and thunderstorms remain possible in the Northwest and northern Rockies. ...Eastern Great Basin into Idaho/Wyoming... Dry and breezy conditions appear likely during the afternoon. Winds of 15-25 mph will be possible along with RH of 15-20%. Even with these elevated to locally critical meteorological conditions, fuels are not likely to become receptive enough to support more than a locally elevated risk. ...Northwest/northern Rockies... While thunderstorms will be possible in association with the upper low, recent precipitation and substantial cloud cover should generally limit the overall risk for lightning ignitions. A continued downward trend in fuel receptiveness is expected Wednesday. Highlights do not appear warranted 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 0259 PM CDT Tue Sep 09 2025 Valid 101200Z - 111200Z ...Washington State... An upper-level trough moving into the western U.S. will support another round of dry thunderstorms through tonight into the early Day 2 period. Numerous new fire ignitions from overnight thunderstorms occurred this morning across central WA. Cloud to ground lightning and minimal rainfall outside thunderstorm rain cores will continue to present an ignition threat in heavier, drought stressed fuels across the WA Cascades, and north central WA, particularly in the morning hours. Thunderstorm development will shift primarily to higher terrain by Wednesday afternoon across central WA. ...Eastern Great Basin and Western Utah... A robust mid-level jet (50-60 knots) rounding the base of the upper-level low over northern California combined with deep, well-mixed boundary layer will support breezy south-southwest surface winds of 15-25 mph Wednesday afternoon. The gusty winds along with relative humidity in the 15-20% range will result in elevated to locally critical fire weather conditions across east-central NV into western UT. Although fuels are only marginally dry, the stronger winds and low RH could contribute to wildfire spread. ..Williams.. 09/09/2025 .PREV DISCUSSION... /ISSUED 1255 AM CDT Tue Sep 09 2025/ ...Synopsis... For Wednesday, not much change in the upper-level pattern is expected from Tuesday. The upper-level trough in the West will shift into more of the Great Basin and the mid-level jet will extend farther northward. Showers and thunderstorms remain possible in the Northwest and northern Rockies. ...Eastern Great Basin into Idaho/Wyoming... Dry and breezy conditions appear likely during the afternoon. Winds of 15-25 mph will be possible along with RH of 15-20%. Even with these elevated to locally critical meteorological conditions, fuels are not likely to become receptive enough to support more than a locally elevated risk. ...Northwest/northern Rockies... While thunderstorms will be possible in association with the upper low, recent precipitation and substantial cloud cover should generally limit the overall risk for lightning ignitions. A continued downward trend in fuel receptiveness is expected Wednesday. Highlights do not appear warranted 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 0259 PM CDT Tue Sep 09 2025 Valid 101200Z - 111200Z ...Washington State... An upper-level trough moving into the western U.S. will support another round of dry thunderstorms through tonight into the early Day 2 period. Numerous new fire ignitions from overnight thunderstorms occurred this morning across central WA. Cloud to ground lightning and minimal rainfall outside thunderstorm rain cores will continue to present an ignition threat in heavier, drought stressed fuels across the WA Cascades, and north central WA, particularly in the morning hours. Thunderstorm development will shift primarily to higher terrain by Wednesday afternoon across central WA. ...Eastern Great Basin and Western Utah... A robust mid-level jet (50-60 knots) rounding the base of the upper-level low over northern California combined with deep, well-mixed boundary layer will support breezy south-southwest surface winds of 15-25 mph Wednesday afternoon. The gusty winds along with relative humidity in the 15-20% range will result in elevated to locally critical fire weather conditions across east-central NV into western UT. Although fuels are only marginally dry, the stronger winds and low RH could contribute to wildfire spread. ..Williams.. 09/09/2025 .PREV DISCUSSION... /ISSUED 1255 AM CDT Tue Sep 09 2025/ ...Synopsis... For Wednesday, not much change in the upper-level pattern is expected from Tuesday. The upper-level trough in the West will shift into more of the Great Basin and the mid-level jet will extend farther northward. Showers and thunderstorms remain possible in the Northwest and northern Rockies. ...Eastern Great Basin into Idaho/Wyoming... Dry and breezy conditions appear likely during the afternoon. Winds of 15-25 mph will be possible along with RH of 15-20%. Even with these elevated to locally critical meteorological conditions, fuels are not likely to become receptive enough to support more than a locally elevated risk. ...Northwest/northern Rockies... While thunderstorms will be possible in association with the upper low, recent precipitation and substantial cloud cover should generally limit the overall risk for lightning ignitions. A continued downward trend in fuel receptiveness is expected Wednesday. Highlights do not appear warranted at this time. ...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 0240 PM CDT Tue Sep 09 2025 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN COLORADO...WESTERN KANSAS...AND THE OKLAHOMA/TEXAS PANHANDLES... ...SUMMARY... Widely scattered severe storms are possible over the central and southern High Plains late this afternoon and evening. ...20z Update - Central/Southern High Plains... The Slight risk (level 2 of 5) has been expanded southward to include southwest KS and portions of the OK/TX Panhandles. This change is based on latest modified RAP/NAM/HRRR/RRFS forecast soundings, CAMs trends, as well as observation trends. Temperatures have warmed into the upper 80s to low 90s F across the region, nearing convective temperatures. Visible satellite imagery shows cumulus developing in southeast CO within modest low-level upslope flow, with minor convergence along the theta-e gradient and surface trough from the northeast TX Panhandle toward the CO/KS border. Isolated to widely scattered thunderstorms are expected to develop by late afternoon and spread east/southeast into this evening. Vertically veering wind profiles, with forecast hodographs becoming elongated/straight above 1-2 km, will support supercells. Steep low and midlevel lapse rates and 1000-2500 J/kg MLCAPE values amid favorable shear will favor large hail, with some potential for stones greater than 2 inch diameter possible. Strong gusts may also accompany stronger convection. ..Leitman.. 09/09/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Sep 09 2025/ ...Central and Southern High Plains... The upper ridge axis will remain over the Rockies today, with northwest flow aloft across the Plains states. High-based thunderstorms are expected to develop off the high terrain of central CO and northern NM by mid-afternoon, while isolated cells form over a remnant boundary over eastern CO/western KS. Backed low-level winds, steep low and mid-level lapse rates, and CAPE values ranging from 1000-2500 J/kg will promote a risk of a few severe storms through the afternoon. Large hail appears to be the main concern, with gusty/damaging winds also possible in the strongest cells. Activity may persist through much of the evening as it progresses eastward into an increasingly moist boundary layer air mass. 12z CAMs show a consistent signal of multiple rounds of storms affecting parts of eastern CO/western KS, so have added a small SLGT risk for this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Tue Sep 09 2025 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN COLORADO...WESTERN KANSAS...AND THE OKLAHOMA/TEXAS PANHANDLES... ...SUMMARY... Widely scattered severe storms are possible over the central and southern High Plains late this afternoon and evening. ...20z Update - Central/Southern High Plains... The Slight risk (level 2 of 5) has been expanded southward to include southwest KS and portions of the OK/TX Panhandles. This change is based on latest modified RAP/NAM/HRRR/RRFS forecast soundings, CAMs trends, as well as observation trends. Temperatures have warmed into the upper 80s to low 90s F across the region, nearing convective temperatures. Visible satellite imagery shows cumulus developing in southeast CO within modest low-level upslope flow, with minor convergence along the theta-e gradient and surface trough from the northeast TX Panhandle toward the CO/KS border. Isolated to widely scattered thunderstorms are expected to develop by late afternoon and spread east/southeast into this evening. Vertically veering wind profiles, with forecast hodographs becoming elongated/straight above 1-2 km, will support supercells. Steep low and midlevel lapse rates and 1000-2500 J/kg MLCAPE values amid favorable shear will favor large hail, with some potential for stones greater than 2 inch diameter possible. Strong gusts may also accompany stronger convection. ..Leitman.. 09/09/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Sep 09 2025/ ...Central and Southern High Plains... The upper ridge axis will remain over the Rockies today, with northwest flow aloft across the Plains states. High-based thunderstorms are expected to develop off the high terrain of central CO and northern NM by mid-afternoon, while isolated cells form over a remnant boundary over eastern CO/western KS. Backed low-level winds, steep low and mid-level lapse rates, and CAPE values ranging from 1000-2500 J/kg will promote a risk of a few severe storms through the afternoon. Large hail appears to be the main concern, with gusty/damaging winds also possible in the strongest cells. Activity may persist through much of the evening as it progresses eastward into an increasingly moist boundary layer air mass. 12z CAMs show a consistent signal of multiple rounds of storms affecting parts of eastern CO/western KS, so have added a small SLGT risk for this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Tue Sep 09 2025 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN COLORADO...WESTERN KANSAS...AND THE OKLAHOMA/TEXAS PANHANDLES... ...SUMMARY... Widely scattered severe storms are possible over the central and southern High Plains late this afternoon and evening. ...20z Update - Central/Southern High Plains... The Slight risk (level 2 of 5) has been expanded southward to include southwest KS and portions of the OK/TX Panhandles. This change is based on latest modified RAP/NAM/HRRR/RRFS forecast soundings, CAMs trends, as well as observation trends. Temperatures have warmed into the upper 80s to low 90s F across the region, nearing convective temperatures. Visible satellite imagery shows cumulus developing in southeast CO within modest low-level upslope flow, with minor convergence along the theta-e gradient and surface trough from the northeast TX Panhandle toward the CO/KS border. Isolated to widely scattered thunderstorms are expected to develop by late afternoon and spread east/southeast into this evening. Vertically veering wind profiles, with forecast hodographs becoming elongated/straight above 1-2 km, will support supercells. Steep low and midlevel lapse rates and 1000-2500 J/kg MLCAPE values amid favorable shear will favor large hail, with some potential for stones greater than 2 inch diameter possible. Strong gusts may also accompany stronger convection. ..Leitman.. 09/09/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Sep 09 2025/ ...Central and Southern High Plains... The upper ridge axis will remain over the Rockies today, with northwest flow aloft across the Plains states. High-based thunderstorms are expected to develop off the high terrain of central CO and northern NM by mid-afternoon, while isolated cells form over a remnant boundary over eastern CO/western KS. Backed low-level winds, steep low and mid-level lapse rates, and CAPE values ranging from 1000-2500 J/kg will promote a risk of a few severe storms through the afternoon. Large hail appears to be the main concern, with gusty/damaging winds also possible in the strongest cells. Activity may persist through much of the evening as it progresses eastward into an increasingly moist boundary layer air mass. 12z CAMs show a consistent signal of multiple rounds of storms affecting parts of eastern CO/western KS, so have added a small SLGT risk for this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Tue Sep 09 2025 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN COLORADO...WESTERN KANSAS...AND THE OKLAHOMA/TEXAS PANHANDLES... ...SUMMARY... Widely scattered severe storms are possible over the central and southern High Plains late this afternoon and evening. ...20z Update - Central/Southern High Plains... The Slight risk (level 2 of 5) has been expanded southward to include southwest KS and portions of the OK/TX Panhandles. This change is based on latest modified RAP/NAM/HRRR/RRFS forecast soundings, CAMs trends, as well as observation trends. Temperatures have warmed into the upper 80s to low 90s F across the region, nearing convective temperatures. Visible satellite imagery shows cumulus developing in southeast CO within modest low-level upslope flow, with minor convergence along the theta-e gradient and surface trough from the northeast TX Panhandle toward the CO/KS border. Isolated to widely scattered thunderstorms are expected to develop by late afternoon and spread east/southeast into this evening. Vertically veering wind profiles, with forecast hodographs becoming elongated/straight above 1-2 km, will support supercells. Steep low and midlevel lapse rates and 1000-2500 J/kg MLCAPE values amid favorable shear will favor large hail, with some potential for stones greater than 2 inch diameter possible. Strong gusts may also accompany stronger convection. ..Leitman.. 09/09/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Sep 09 2025/ ...Central and Southern High Plains... The upper ridge axis will remain over the Rockies today, with northwest flow aloft across the Plains states. High-based thunderstorms are expected to develop off the high terrain of central CO and northern NM by mid-afternoon, while isolated cells form over a remnant boundary over eastern CO/western KS. Backed low-level winds, steep low and mid-level lapse rates, and CAPE values ranging from 1000-2500 J/kg will promote a risk of a few severe storms through the afternoon. Large hail appears to be the main concern, with gusty/damaging winds also possible in the strongest cells. Activity may persist through much of the evening as it progresses eastward into an increasingly moist boundary layer air mass. 12z CAMs show a consistent signal of multiple rounds of storms affecting parts of eastern CO/western KS, so have added a small SLGT risk for this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Tue Sep 09 2025 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN COLORADO...WESTERN KANSAS...AND THE OKLAHOMA/TEXAS PANHANDLES... ...SUMMARY... Widely scattered severe storms are possible over the central and southern High Plains late this afternoon and evening. ...20z Update - Central/Southern High Plains... The Slight risk (level 2 of 5) has been expanded southward to include southwest KS and portions of the OK/TX Panhandles. This change is based on latest modified RAP/NAM/HRRR/RRFS forecast soundings, CAMs trends, as well as observation trends. Temperatures have warmed into the upper 80s to low 90s F across the region, nearing convective temperatures. Visible satellite imagery shows cumulus developing in southeast CO within modest low-level upslope flow, with minor convergence along the theta-e gradient and surface trough from the northeast TX Panhandle toward the CO/KS border. Isolated to widely scattered thunderstorms are expected to develop by late afternoon and spread east/southeast into this evening. Vertically veering wind profiles, with forecast hodographs becoming elongated/straight above 1-2 km, will support supercells. Steep low and midlevel lapse rates and 1000-2500 J/kg MLCAPE values amid favorable shear will favor large hail, with some potential for stones greater than 2 inch diameter possible. Strong gusts may also accompany stronger convection. ..Leitman.. 09/09/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Sep 09 2025/ ...Central and Southern High Plains... The upper ridge axis will remain over the Rockies today, with northwest flow aloft across the Plains states. High-based thunderstorms are expected to develop off the high terrain of central CO and northern NM by mid-afternoon, while isolated cells form over a remnant boundary over eastern CO/western KS. Backed low-level winds, steep low and mid-level lapse rates, and CAPE values ranging from 1000-2500 J/kg will promote a risk of a few severe storms through the afternoon. Large hail appears to be the main concern, with gusty/damaging winds also possible in the strongest cells. Activity may persist through much of the evening as it progresses eastward into an increasingly moist boundary layer air mass. 12z CAMs show a consistent signal of multiple rounds of storms affecting parts of eastern CO/western KS, so have added a small SLGT risk for this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Tue Sep 09 2025 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN COLORADO...WESTERN KANSAS...AND THE OKLAHOMA/TEXAS PANHANDLES... ...SUMMARY... Widely scattered severe storms are possible over the central and southern High Plains late this afternoon and evening. ...20z Update - Central/Southern High Plains... The Slight risk (level 2 of 5) has been expanded southward to include southwest KS and portions of the OK/TX Panhandles. This change is based on latest modified RAP/NAM/HRRR/RRFS forecast soundings, CAMs trends, as well as observation trends. Temperatures have warmed into the upper 80s to low 90s F across the region, nearing convective temperatures. Visible satellite imagery shows cumulus developing in southeast CO within modest low-level upslope flow, with minor convergence along the theta-e gradient and surface trough from the northeast TX Panhandle toward the CO/KS border. Isolated to widely scattered thunderstorms are expected to develop by late afternoon and spread east/southeast into this evening. Vertically veering wind profiles, with forecast hodographs becoming elongated/straight above 1-2 km, will support supercells. Steep low and midlevel lapse rates and 1000-2500 J/kg MLCAPE values amid favorable shear will favor large hail, with some potential for stones greater than 2 inch diameter possible. Strong gusts may also accompany stronger convection. ..Leitman.. 09/09/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Sep 09 2025/ ...Central and Southern High Plains... The upper ridge axis will remain over the Rockies today, with northwest flow aloft across the Plains states. High-based thunderstorms are expected to develop off the high terrain of central CO and northern NM by mid-afternoon, while isolated cells form over a remnant boundary over eastern CO/western KS. Backed low-level winds, steep low and mid-level lapse rates, and CAPE values ranging from 1000-2500 J/kg will promote a risk of a few severe storms through the afternoon. Large hail appears to be the main concern, with gusty/damaging winds also possible in the strongest cells. Activity may persist through much of the evening as it progresses eastward into an increasingly moist boundary layer air mass. 12z CAMs show a consistent signal of multiple rounds of storms affecting parts of eastern CO/western KS, so have added a small SLGT risk for this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Tue Sep 09 2025 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN COLORADO...WESTERN KANSAS...AND THE OKLAHOMA/TEXAS PANHANDLES... ...SUMMARY... Widely scattered severe storms are possible over the central and southern High Plains late this afternoon and evening. ...20z Update - Central/Southern High Plains... The Slight risk (level 2 of 5) has been expanded southward to include southwest KS and portions of the OK/TX Panhandles. This change is based on latest modified RAP/NAM/HRRR/RRFS forecast soundings, CAMs trends, as well as observation trends. Temperatures have warmed into the upper 80s to low 90s F across the region, nearing convective temperatures. Visible satellite imagery shows cumulus developing in southeast CO within modest low-level upslope flow, with minor convergence along the theta-e gradient and surface trough from the northeast TX Panhandle toward the CO/KS border. Isolated to widely scattered thunderstorms are expected to develop by late afternoon and spread east/southeast into this evening. Vertically veering wind profiles, with forecast hodographs becoming elongated/straight above 1-2 km, will support supercells. Steep low and midlevel lapse rates and 1000-2500 J/kg MLCAPE values amid favorable shear will favor large hail, with some potential for stones greater than 2 inch diameter possible. Strong gusts may also accompany stronger convection. ..Leitman.. 09/09/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Sep 09 2025/ ...Central and Southern High Plains... The upper ridge axis will remain over the Rockies today, with northwest flow aloft across the Plains states. High-based thunderstorms are expected to develop off the high terrain of central CO and northern NM by mid-afternoon, while isolated cells form over a remnant boundary over eastern CO/western KS. Backed low-level winds, steep low and mid-level lapse rates, and CAPE values ranging from 1000-2500 J/kg will promote a risk of a few severe storms through the afternoon. Large hail appears to be the main concern, with gusty/damaging winds also possible in the strongest cells. Activity may persist through much of the evening as it progresses eastward into an increasingly moist boundary layer air mass. 12z CAMs show a consistent signal of multiple rounds of storms affecting parts of eastern CO/western KS, so have added a small SLGT risk for this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Tue Sep 09 2025 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN COLORADO...WESTERN KANSAS...AND THE OKLAHOMA/TEXAS PANHANDLES... ...SUMMARY... Widely scattered severe storms are possible over the central and southern High Plains late this afternoon and evening. ...20z Update - Central/Southern High Plains... The Slight risk (level 2 of 5) has been expanded southward to include southwest KS and portions of the OK/TX Panhandles. This change is based on latest modified RAP/NAM/HRRR/RRFS forecast soundings, CAMs trends, as well as observation trends. Temperatures have warmed into the upper 80s to low 90s F across the region, nearing convective temperatures. Visible satellite imagery shows cumulus developing in southeast CO within modest low-level upslope flow, with minor convergence along the theta-e gradient and surface trough from the northeast TX Panhandle toward the CO/KS border. Isolated to widely scattered thunderstorms are expected to develop by late afternoon and spread east/southeast into this evening. Vertically veering wind profiles, with forecast hodographs becoming elongated/straight above 1-2 km, will support supercells. Steep low and midlevel lapse rates and 1000-2500 J/kg MLCAPE values amid favorable shear will favor large hail, with some potential for stones greater than 2 inch diameter possible. Strong gusts may also accompany stronger convection. ..Leitman.. 09/09/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Sep 09 2025/ ...Central and Southern High Plains... The upper ridge axis will remain over the Rockies today, with northwest flow aloft across the Plains states. High-based thunderstorms are expected to develop off the high terrain of central CO and northern NM by mid-afternoon, while isolated cells form over a remnant boundary over eastern CO/western KS. Backed low-level winds, steep low and mid-level lapse rates, and CAPE values ranging from 1000-2500 J/kg will promote a risk of a few severe storms through the afternoon. Large hail appears to be the main concern, with gusty/damaging winds also possible in the strongest cells. Activity may persist through much of the evening as it progresses eastward into an increasingly moist boundary layer air mass. 12z CAMs show a consistent signal of multiple rounds of storms affecting parts of eastern CO/western KS, so have added a small SLGT risk for this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Tue Sep 09 2025 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN COLORADO...WESTERN KANSAS...AND THE OKLAHOMA/TEXAS PANHANDLES... ...SUMMARY... Widely scattered severe storms are possible over the central and southern High Plains late this afternoon and evening. ...20z Update - Central/Southern High Plains... The Slight risk (level 2 of 5) has been expanded southward to include southwest KS and portions of the OK/TX Panhandles. This change is based on latest modified RAP/NAM/HRRR/RRFS forecast soundings, CAMs trends, as well as observation trends. Temperatures have warmed into the upper 80s to low 90s F across the region, nearing convective temperatures. Visible satellite imagery shows cumulus developing in southeast CO within modest low-level upslope flow, with minor convergence along the theta-e gradient and surface trough from the northeast TX Panhandle toward the CO/KS border. Isolated to widely scattered thunderstorms are expected to develop by late afternoon and spread east/southeast into this evening. Vertically veering wind profiles, with forecast hodographs becoming elongated/straight above 1-2 km, will support supercells. Steep low and midlevel lapse rates and 1000-2500 J/kg MLCAPE values amid favorable shear will favor large hail, with some potential for stones greater than 2 inch diameter possible. Strong gusts may also accompany stronger convection. ..Leitman.. 09/09/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Sep 09 2025/ ...Central and Southern High Plains... The upper ridge axis will remain over the Rockies today, with northwest flow aloft across the Plains states. High-based thunderstorms are expected to develop off the high terrain of central CO and northern NM by mid-afternoon, while isolated cells form over a remnant boundary over eastern CO/western KS. Backed low-level winds, steep low and mid-level lapse rates, and CAPE values ranging from 1000-2500 J/kg will promote a risk of a few severe storms through the afternoon. Large hail appears to be the main concern, with gusty/damaging winds also possible in the strongest cells. Activity may persist through much of the evening as it progresses eastward into an increasingly moist boundary layer air mass. 12z CAMs show a consistent signal of multiple rounds of storms affecting parts of eastern CO/western KS, so have added a small SLGT risk for this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Tue Sep 09 2025 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN COLORADO...WESTERN KANSAS...AND THE OKLAHOMA/TEXAS PANHANDLES... ...SUMMARY... Widely scattered severe storms are possible over the central and southern High Plains late this afternoon and evening. ...20z Update - Central/Southern High Plains... The Slight risk (level 2 of 5) has been expanded southward to include southwest KS and portions of the OK/TX Panhandles. This change is based on latest modified RAP/NAM/HRRR/RRFS forecast soundings, CAMs trends, as well as observation trends. Temperatures have warmed into the upper 80s to low 90s F across the region, nearing convective temperatures. Visible satellite imagery shows cumulus developing in southeast CO within modest low-level upslope flow, with minor convergence along the theta-e gradient and surface trough from the northeast TX Panhandle toward the CO/KS border. Isolated to widely scattered thunderstorms are expected to develop by late afternoon and spread east/southeast into this evening. Vertically veering wind profiles, with forecast hodographs becoming elongated/straight above 1-2 km, will support supercells. Steep low and midlevel lapse rates and 1000-2500 J/kg MLCAPE values amid favorable shear will favor large hail, with some potential for stones greater than 2 inch diameter possible. Strong gusts may also accompany stronger convection. ..Leitman.. 09/09/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Sep 09 2025/ ...Central and Southern High Plains... The upper ridge axis will remain over the Rockies today, with northwest flow aloft across the Plains states. High-based thunderstorms are expected to develop off the high terrain of central CO and northern NM by mid-afternoon, while isolated cells form over a remnant boundary over eastern CO/western KS. Backed low-level winds, steep low and mid-level lapse rates, and CAPE values ranging from 1000-2500 J/kg will promote a risk of a few severe storms through the afternoon. Large hail appears to be the main concern, with gusty/damaging winds also possible in the strongest cells. Activity may persist through much of the evening as it progresses eastward into an increasingly moist boundary layer air mass. 12z CAMs show a consistent signal of multiple rounds of storms affecting parts of eastern CO/western KS, so have added a small SLGT risk for this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Tue Sep 09 2025 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN COLORADO...WESTERN KANSAS...AND THE OKLAHOMA/TEXAS PANHANDLES... ...SUMMARY... Widely scattered severe storms are possible over the central and southern High Plains late this afternoon and evening. ...20z Update - Central/Southern High Plains... The Slight risk (level 2 of 5) has been expanded southward to include southwest KS and portions of the OK/TX Panhandles. This change is based on latest modified RAP/NAM/HRRR/RRFS forecast soundings, CAMs trends, as well as observation trends. Temperatures have warmed into the upper 80s to low 90s F across the region, nearing convective temperatures. Visible satellite imagery shows cumulus developing in southeast CO within modest low-level upslope flow, with minor convergence along the theta-e gradient and surface trough from the northeast TX Panhandle toward the CO/KS border. Isolated to widely scattered thunderstorms are expected to develop by late afternoon and spread east/southeast into this evening. Vertically veering wind profiles, with forecast hodographs becoming elongated/straight above 1-2 km, will support supercells. Steep low and midlevel lapse rates and 1000-2500 J/kg MLCAPE values amid favorable shear will favor large hail, with some potential for stones greater than 2 inch diameter possible. Strong gusts may also accompany stronger convection. ..Leitman.. 09/09/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Sep 09 2025/ ...Central and Southern High Plains... The upper ridge axis will remain over the Rockies today, with northwest flow aloft across the Plains states. High-based thunderstorms are expected to develop off the high terrain of central CO and northern NM by mid-afternoon, while isolated cells form over a remnant boundary over eastern CO/western KS. Backed low-level winds, steep low and mid-level lapse rates, and CAPE values ranging from 1000-2500 J/kg will promote a risk of a few severe storms through the afternoon. Large hail appears to be the main concern, with gusty/damaging winds also possible in the strongest cells. Activity may persist through much of the evening as it progresses eastward into an increasingly moist boundary layer air mass. 12z CAMs show a consistent signal of multiple rounds of storms affecting parts of eastern CO/western KS, so have added a small SLGT risk for this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Tue Sep 09 2025 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN COLORADO...WESTERN KANSAS...AND THE OKLAHOMA/TEXAS PANHANDLES... ...SUMMARY... Widely scattered severe storms are possible over the central and southern High Plains late this afternoon and evening. ...20z Update - Central/Southern High Plains... The Slight risk (level 2 of 5) has been expanded southward to include southwest KS and portions of the OK/TX Panhandles. This change is based on latest modified RAP/NAM/HRRR/RRFS forecast soundings, CAMs trends, as well as observation trends. Temperatures have warmed into the upper 80s to low 90s F across the region, nearing convective temperatures. Visible satellite imagery shows cumulus developing in southeast CO within modest low-level upslope flow, with minor convergence along the theta-e gradient and surface trough from the northeast TX Panhandle toward the CO/KS border. Isolated to widely scattered thunderstorms are expected to develop by late afternoon and spread east/southeast into this evening. Vertically veering wind profiles, with forecast hodographs becoming elongated/straight above 1-2 km, will support supercells. Steep low and midlevel lapse rates and 1000-2500 J/kg MLCAPE values amid favorable shear will favor large hail, with some potential for stones greater than 2 inch diameter possible. Strong gusts may also accompany stronger convection. ..Leitman.. 09/09/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Sep 09 2025/ ...Central and Southern High Plains... The upper ridge axis will remain over the Rockies today, with northwest flow aloft across the Plains states. High-based thunderstorms are expected to develop off the high terrain of central CO and northern NM by mid-afternoon, while isolated cells form over a remnant boundary over eastern CO/western KS. Backed low-level winds, steep low and mid-level lapse rates, and CAPE values ranging from 1000-2500 J/kg will promote a risk of a few severe storms through the afternoon. Large hail appears to be the main concern, with gusty/damaging winds also possible in the strongest cells. Activity may persist through much of the evening as it progresses eastward into an increasingly moist boundary layer air mass. 12z CAMs show a consistent signal of multiple rounds of storms affecting parts of eastern CO/western KS, so have added a small SLGT risk for this region. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0240 PM CDT Tue Sep 09 2025 Valid 092000Z - 101200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN COLORADO...WESTERN KANSAS...AND THE OKLAHOMA/TEXAS PANHANDLES... ...SUMMARY... Widely scattered severe storms are possible over the central and southern High Plains late this afternoon and evening. ...20z Update - Central/Southern High Plains... The Slight risk (level 2 of 5) has been expanded southward to include southwest KS and portions of the OK/TX Panhandles. This change is based on latest modified RAP/NAM/HRRR/RRFS forecast soundings, CAMs trends, as well as observation trends. Temperatures have warmed into the upper 80s to low 90s F across the region, nearing convective temperatures. Visible satellite imagery shows cumulus developing in southeast CO within modest low-level upslope flow, with minor convergence along the theta-e gradient and surface trough from the northeast TX Panhandle toward the CO/KS border. Isolated to widely scattered thunderstorms are expected to develop by late afternoon and spread east/southeast into this evening. Vertically veering wind profiles, with forecast hodographs becoming elongated/straight above 1-2 km, will support supercells. Steep low and midlevel lapse rates and 1000-2500 J/kg MLCAPE values amid favorable shear will favor large hail, with some potential for stones greater than 2 inch diameter possible. Strong gusts may also accompany stronger convection. ..Leitman.. 09/09/2025 .PREV DISCUSSION... /ISSUED 1121 AM CDT Tue Sep 09 2025/ ...Central and Southern High Plains... The upper ridge axis will remain over the Rockies today, with northwest flow aloft across the Plains states. High-based thunderstorms are expected to develop off the high terrain of central CO and northern NM by mid-afternoon, while isolated cells form over a remnant boundary over eastern CO/western KS. Backed low-level winds, steep low and mid-level lapse rates, and CAPE values ranging from 1000-2500 J/kg will promote a risk of a few severe storms through the afternoon. Large hail appears to be the main concern, with gusty/damaging winds also possible in the strongest cells. Activity may persist through much of the evening as it progresses eastward into an increasingly moist boundary layer air mass. 12z CAMs show a consistent signal of multiple rounds of storms affecting parts of eastern CO/western KS, so have added a small SLGT risk for this region. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0153 PM CDT Tue Sep 09 2025 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS WESTERN SOUTH DAKOTA...MUCH OF NORTH DAKOTA...AND EASTERN MONTANA... ...SUMMARY... Isolated strong to severe thunderstorms are possible across Montana and the Dakotas on Thursday. Additional isolated storms are possible across the southern High Plains and Intermountain West. ...Discussion... Persistent southwesterly flow across the Rockies will maintain persistent lee troughing across the central/northern High Plains. East of this lee trough, a large reservoir of low to mid 60s dewpoints will be present across the Plains which will lead to moderate instability from Kansas to the Canadian border. Isolated thunderstorms may be possible by Thursday afternoon as inhibition erodes along this trough axis. Organized thunderstorms will be most likely from southwest South Dakota to western North Dakota/eastern Montana where stronger mid-level flow and weak height falls will be present. Very steep mid-level lapse rates and somewhat dry low-levels will support the potential for large hail some severe wind gust threat. Overall, weak forcing may keep storm coverage isolated. However, if greater storm coverage occurs, a hail driven Slight Risk may be warranted given at least marginal supercell wind profiles across the region. ..Bentley.. 09/09/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0153 PM CDT Tue Sep 09 2025 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS WESTERN SOUTH DAKOTA...MUCH OF NORTH DAKOTA...AND EASTERN MONTANA... ...SUMMARY... Isolated strong to severe thunderstorms are possible across Montana and the Dakotas on Thursday. Additional isolated storms are possible across the southern High Plains and Intermountain West. ...Discussion... Persistent southwesterly flow across the Rockies will maintain persistent lee troughing across the central/northern High Plains. East of this lee trough, a large reservoir of low to mid 60s dewpoints will be present across the Plains which will lead to moderate instability from Kansas to the Canadian border. Isolated thunderstorms may be possible by Thursday afternoon as inhibition erodes along this trough axis. Organized thunderstorms will be most likely from southwest South Dakota to western North Dakota/eastern Montana where stronger mid-level flow and weak height falls will be present. Very steep mid-level lapse rates and somewhat dry low-levels will support the potential for large hail some severe wind gust threat. Overall, weak forcing may keep storm coverage isolated. However, if greater storm coverage occurs, a hail driven Slight Risk may be warranted given at least marginal supercell wind profiles across the region. ..Bentley.. 09/09/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0153 PM CDT Tue Sep 09 2025 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS WESTERN SOUTH DAKOTA...MUCH OF NORTH DAKOTA...AND EASTERN MONTANA... ...SUMMARY... Isolated strong to severe thunderstorms are possible across Montana and the Dakotas on Thursday. Additional isolated storms are possible across the southern High Plains and Intermountain West. ...Discussion... Persistent southwesterly flow across the Rockies will maintain persistent lee troughing across the central/northern High Plains. East of this lee trough, a large reservoir of low to mid 60s dewpoints will be present across the Plains which will lead to moderate instability from Kansas to the Canadian border. Isolated thunderstorms may be possible by Thursday afternoon as inhibition erodes along this trough axis. Organized thunderstorms will be most likely from southwest South Dakota to western North Dakota/eastern Montana where stronger mid-level flow and weak height falls will be present. Very steep mid-level lapse rates and somewhat dry low-levels will support the potential for large hail some severe wind gust threat. Overall, weak forcing may keep storm coverage isolated. However, if greater storm coverage occurs, a hail driven Slight Risk may be warranted given at least marginal supercell wind profiles across the region. ..Bentley.. 09/09/2025 Read more