Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0137 AM CDT Fri Sep 05 2025 Valid 051200Z - 061200Z ...Synopsis... A mid-level trough will traverse the Midwest/Great Lakes Regions as upper ridging remains in place over the Interior West, but with a small but pronounced mid-level impulse impinging on the northern California coastline today. This impulse, in tandem with adequate instability, will provide enough lift to support at least scattered thunderstorms to portions of the Pacific Northwest this afternoon into the overnight hours. These storms will move atop a modestly dry boundary layer, with wet and dry storm modes both possible. Nonetheless, these storms will overspread dry fuel beds, especially from the central/northern Cascades and points east. Dry thunderstorm highlights remain in place for the possibility of lightning strikes (some dry) posing a hazard for fuel ignition. ..Squitieri.. 09/05/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0137 AM CDT Fri Sep 05 2025 Valid 051200Z - 061200Z ...Synopsis... A mid-level trough will traverse the Midwest/Great Lakes Regions as upper ridging remains in place over the Interior West, but with a small but pronounced mid-level impulse impinging on the northern California coastline today. This impulse, in tandem with adequate instability, will provide enough lift to support at least scattered thunderstorms to portions of the Pacific Northwest this afternoon into the overnight hours. These storms will move atop a modestly dry boundary layer, with wet and dry storm modes both possible. Nonetheless, these storms will overspread dry fuel beds, especially from the central/northern Cascades and points east. Dry thunderstorm highlights remain in place for the possibility of lightning strikes (some dry) posing a hazard for fuel ignition. ..Squitieri.. 09/05/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0137 AM CDT Fri Sep 05 2025 Valid 051200Z - 061200Z ...Synopsis... A mid-level trough will traverse the Midwest/Great Lakes Regions as upper ridging remains in place over the Interior West, but with a small but pronounced mid-level impulse impinging on the northern California coastline today. This impulse, in tandem with adequate instability, will provide enough lift to support at least scattered thunderstorms to portions of the Pacific Northwest this afternoon into the overnight hours. These storms will move atop a modestly dry boundary layer, with wet and dry storm modes both possible. Nonetheless, these storms will overspread dry fuel beds, especially from the central/northern Cascades and points east. Dry thunderstorm highlights remain in place for the possibility of lightning strikes (some dry) posing a hazard for fuel ignition. ..Squitieri.. 09/05/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1251 AM CDT Fri Sep 05 2025 Valid 061200Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE MID-ATLANTIC INTO NEW ENGLAND... ...SUMMARY... Widely scattered to scattered thunderstorms will pose primarily a risk of damaging wind gusts across parts of the Mid-Atlantic into New England on Saturday. ...Synopsis... Troughing will remain across the Midwest into the Northeast on Saturday. A cold front along/near the Appalachians will make eastward progress through the day. Severe potential will focus along and ahead of this front depending on where destabilization can occur. Another shortwave trough will move through northern California into the Northwest. ...Mid-Atlantic into New England... A surface cold front in the general vicinity of the Appalachians will be the focus for potential afternoon thunderstorm development. The timing of this feature remains uncertain in guidance. This timing, along with cloud cover associated with the Great Lakes trough, will play a large role in where destabilization can occur during the afternoon. Confidence in storm coverage is higher with northward extent given the better mid-level ascent across southern New England. However, this area also may have greater cloud cover concerns. Even so, there are models that show temperatures in the upper 70s to low 80s F. Should these warmer temperatures occur, there will likely be a narrow corridor of greater severe potential from southern New England into northern portions of the Mid-Atlantic region. Strong/damaging winds would be the primary hazard as convection mixes down the stronger 850 mb winds. Mid-level lapse rates will be rather poor, though long hodographs could promote marginally severe hail in any discrete storms that can develop and persist. Discrete modes will likely be short-lived given the deep-layer flow parallel to the cold front. Farther south into the Piedmont, surface heating and buoyancy will be greater. Shear will eventually taper off with southern extent. However, mid-level ascent will be weaker with near neutral mid-level height tendencies. Storm coverage may end up tied to locally greater ascent from a subtle shortwave/MCV. Isolated wind damage would be possible with the strongest storms. ...Northwest... A compact shortwave trough should move through Oregon, favorably timed with peak diurnal heating. Widely scattered to scattered storms will be possible. Temperatures of around -13 to -15 C at 500 mb will support at least low-end buoyancy. The primary uncertainty with regard to severe potential will be the quality of low-level moisture. Most models suggest strong mixing will occur with the NAM being the outlier with low-level moisture. There is additional uncertainty in surface heating given smoke within the region. Confidence in severe storm coverage is too low for probabilities, but strong to marginally severe surface gusts and isolated hail would be possible if greater moisture remains during the afternoon. ..Wendt.. 09/05/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1251 AM CDT Fri Sep 05 2025 Valid 061200Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE MID-ATLANTIC INTO NEW ENGLAND... ...SUMMARY... Widely scattered to scattered thunderstorms will pose primarily a risk of damaging wind gusts across parts of the Mid-Atlantic into New England on Saturday. ...Synopsis... Troughing will remain across the Midwest into the Northeast on Saturday. A cold front along/near the Appalachians will make eastward progress through the day. Severe potential will focus along and ahead of this front depending on where destabilization can occur. Another shortwave trough will move through northern California into the Northwest. ...Mid-Atlantic into New England... A surface cold front in the general vicinity of the Appalachians will be the focus for potential afternoon thunderstorm development. The timing of this feature remains uncertain in guidance. This timing, along with cloud cover associated with the Great Lakes trough, will play a large role in where destabilization can occur during the afternoon. Confidence in storm coverage is higher with northward extent given the better mid-level ascent across southern New England. However, this area also may have greater cloud cover concerns. Even so, there are models that show temperatures in the upper 70s to low 80s F. Should these warmer temperatures occur, there will likely be a narrow corridor of greater severe potential from southern New England into northern portions of the Mid-Atlantic region. Strong/damaging winds would be the primary hazard as convection mixes down the stronger 850 mb winds. Mid-level lapse rates will be rather poor, though long hodographs could promote marginally severe hail in any discrete storms that can develop and persist. Discrete modes will likely be short-lived given the deep-layer flow parallel to the cold front. Farther south into the Piedmont, surface heating and buoyancy will be greater. Shear will eventually taper off with southern extent. However, mid-level ascent will be weaker with near neutral mid-level height tendencies. Storm coverage may end up tied to locally greater ascent from a subtle shortwave/MCV. Isolated wind damage would be possible with the strongest storms. ...Northwest... A compact shortwave trough should move through Oregon, favorably timed with peak diurnal heating. Widely scattered to scattered storms will be possible. Temperatures of around -13 to -15 C at 500 mb will support at least low-end buoyancy. The primary uncertainty with regard to severe potential will be the quality of low-level moisture. Most models suggest strong mixing will occur with the NAM being the outlier with low-level moisture. There is additional uncertainty in surface heating given smoke within the region. Confidence in severe storm coverage is too low for probabilities, but strong to marginally severe surface gusts and isolated hail would be possible if greater moisture remains during the afternoon. ..Wendt.. 09/05/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1251 AM CDT Fri Sep 05 2025 Valid 061200Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE MID-ATLANTIC INTO NEW ENGLAND... ...SUMMARY... Widely scattered to scattered thunderstorms will pose primarily a risk of damaging wind gusts across parts of the Mid-Atlantic into New England on Saturday. ...Synopsis... Troughing will remain across the Midwest into the Northeast on Saturday. A cold front along/near the Appalachians will make eastward progress through the day. Severe potential will focus along and ahead of this front depending on where destabilization can occur. Another shortwave trough will move through northern California into the Northwest. ...Mid-Atlantic into New England... A surface cold front in the general vicinity of the Appalachians will be the focus for potential afternoon thunderstorm development. The timing of this feature remains uncertain in guidance. This timing, along with cloud cover associated with the Great Lakes trough, will play a large role in where destabilization can occur during the afternoon. Confidence in storm coverage is higher with northward extent given the better mid-level ascent across southern New England. However, this area also may have greater cloud cover concerns. Even so, there are models that show temperatures in the upper 70s to low 80s F. Should these warmer temperatures occur, there will likely be a narrow corridor of greater severe potential from southern New England into northern portions of the Mid-Atlantic region. Strong/damaging winds would be the primary hazard as convection mixes down the stronger 850 mb winds. Mid-level lapse rates will be rather poor, though long hodographs could promote marginally severe hail in any discrete storms that can develop and persist. Discrete modes will likely be short-lived given the deep-layer flow parallel to the cold front. Farther south into the Piedmont, surface heating and buoyancy will be greater. Shear will eventually taper off with southern extent. However, mid-level ascent will be weaker with near neutral mid-level height tendencies. Storm coverage may end up tied to locally greater ascent from a subtle shortwave/MCV. Isolated wind damage would be possible with the strongest storms. ...Northwest... A compact shortwave trough should move through Oregon, favorably timed with peak diurnal heating. Widely scattered to scattered storms will be possible. Temperatures of around -13 to -15 C at 500 mb will support at least low-end buoyancy. The primary uncertainty with regard to severe potential will be the quality of low-level moisture. Most models suggest strong mixing will occur with the NAM being the outlier with low-level moisture. There is additional uncertainty in surface heating given smoke within the region. Confidence in severe storm coverage is too low for probabilities, but strong to marginally severe surface gusts and isolated hail would be possible if greater moisture remains during the afternoon. ..Wendt.. 09/05/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1251 AM CDT Fri Sep 05 2025 Valid 061200Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE MID-ATLANTIC INTO NEW ENGLAND... ...SUMMARY... Widely scattered to scattered thunderstorms will pose primarily a risk of damaging wind gusts across parts of the Mid-Atlantic into New England on Saturday. ...Synopsis... Troughing will remain across the Midwest into the Northeast on Saturday. A cold front along/near the Appalachians will make eastward progress through the day. Severe potential will focus along and ahead of this front depending on where destabilization can occur. Another shortwave trough will move through northern California into the Northwest. ...Mid-Atlantic into New England... A surface cold front in the general vicinity of the Appalachians will be the focus for potential afternoon thunderstorm development. The timing of this feature remains uncertain in guidance. This timing, along with cloud cover associated with the Great Lakes trough, will play a large role in where destabilization can occur during the afternoon. Confidence in storm coverage is higher with northward extent given the better mid-level ascent across southern New England. However, this area also may have greater cloud cover concerns. Even so, there are models that show temperatures in the upper 70s to low 80s F. Should these warmer temperatures occur, there will likely be a narrow corridor of greater severe potential from southern New England into northern portions of the Mid-Atlantic region. Strong/damaging winds would be the primary hazard as convection mixes down the stronger 850 mb winds. Mid-level lapse rates will be rather poor, though long hodographs could promote marginally severe hail in any discrete storms that can develop and persist. Discrete modes will likely be short-lived given the deep-layer flow parallel to the cold front. Farther south into the Piedmont, surface heating and buoyancy will be greater. Shear will eventually taper off with southern extent. However, mid-level ascent will be weaker with near neutral mid-level height tendencies. Storm coverage may end up tied to locally greater ascent from a subtle shortwave/MCV. Isolated wind damage would be possible with the strongest storms. ...Northwest... A compact shortwave trough should move through Oregon, favorably timed with peak diurnal heating. Widely scattered to scattered storms will be possible. Temperatures of around -13 to -15 C at 500 mb will support at least low-end buoyancy. The primary uncertainty with regard to severe potential will be the quality of low-level moisture. Most models suggest strong mixing will occur with the NAM being the outlier with low-level moisture. There is additional uncertainty in surface heating given smoke within the region. Confidence in severe storm coverage is too low for probabilities, but strong to marginally severe surface gusts and isolated hail would be possible if greater moisture remains during the afternoon. ..Wendt.. 09/05/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1251 AM CDT Fri Sep 05 2025 Valid 061200Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE MID-ATLANTIC INTO NEW ENGLAND... ...SUMMARY... Widely scattered to scattered thunderstorms will pose primarily a risk of damaging wind gusts across parts of the Mid-Atlantic into New England on Saturday. ...Synopsis... Troughing will remain across the Midwest into the Northeast on Saturday. A cold front along/near the Appalachians will make eastward progress through the day. Severe potential will focus along and ahead of this front depending on where destabilization can occur. Another shortwave trough will move through northern California into the Northwest. ...Mid-Atlantic into New England... A surface cold front in the general vicinity of the Appalachians will be the focus for potential afternoon thunderstorm development. The timing of this feature remains uncertain in guidance. This timing, along with cloud cover associated with the Great Lakes trough, will play a large role in where destabilization can occur during the afternoon. Confidence in storm coverage is higher with northward extent given the better mid-level ascent across southern New England. However, this area also may have greater cloud cover concerns. Even so, there are models that show temperatures in the upper 70s to low 80s F. Should these warmer temperatures occur, there will likely be a narrow corridor of greater severe potential from southern New England into northern portions of the Mid-Atlantic region. Strong/damaging winds would be the primary hazard as convection mixes down the stronger 850 mb winds. Mid-level lapse rates will be rather poor, though long hodographs could promote marginally severe hail in any discrete storms that can develop and persist. Discrete modes will likely be short-lived given the deep-layer flow parallel to the cold front. Farther south into the Piedmont, surface heating and buoyancy will be greater. Shear will eventually taper off with southern extent. However, mid-level ascent will be weaker with near neutral mid-level height tendencies. Storm coverage may end up tied to locally greater ascent from a subtle shortwave/MCV. Isolated wind damage would be possible with the strongest storms. ...Northwest... A compact shortwave trough should move through Oregon, favorably timed with peak diurnal heating. Widely scattered to scattered storms will be possible. Temperatures of around -13 to -15 C at 500 mb will support at least low-end buoyancy. The primary uncertainty with regard to severe potential will be the quality of low-level moisture. Most models suggest strong mixing will occur with the NAM being the outlier with low-level moisture. There is additional uncertainty in surface heating given smoke within the region. Confidence in severe storm coverage is too low for probabilities, but strong to marginally severe surface gusts and isolated hail would be possible if greater moisture remains during the afternoon. ..Wendt.. 09/05/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1251 AM CDT Fri Sep 05 2025 Valid 061200Z - 071200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE MID-ATLANTIC INTO NEW ENGLAND... ...SUMMARY... Widely scattered to scattered thunderstorms will pose primarily a risk of damaging wind gusts across parts of the Mid-Atlantic into New England on Saturday. ...Synopsis... Troughing will remain across the Midwest into the Northeast on Saturday. A cold front along/near the Appalachians will make eastward progress through the day. Severe potential will focus along and ahead of this front depending on where destabilization can occur. Another shortwave trough will move through northern California into the Northwest. ...Mid-Atlantic into New England... A surface cold front in the general vicinity of the Appalachians will be the focus for potential afternoon thunderstorm development. The timing of this feature remains uncertain in guidance. This timing, along with cloud cover associated with the Great Lakes trough, will play a large role in where destabilization can occur during the afternoon. Confidence in storm coverage is higher with northward extent given the better mid-level ascent across southern New England. However, this area also may have greater cloud cover concerns. Even so, there are models that show temperatures in the upper 70s to low 80s F. Should these warmer temperatures occur, there will likely be a narrow corridor of greater severe potential from southern New England into northern portions of the Mid-Atlantic region. Strong/damaging winds would be the primary hazard as convection mixes down the stronger 850 mb winds. Mid-level lapse rates will be rather poor, though long hodographs could promote marginally severe hail in any discrete storms that can develop and persist. Discrete modes will likely be short-lived given the deep-layer flow parallel to the cold front. Farther south into the Piedmont, surface heating and buoyancy will be greater. Shear will eventually taper off with southern extent. However, mid-level ascent will be weaker with near neutral mid-level height tendencies. Storm coverage may end up tied to locally greater ascent from a subtle shortwave/MCV. Isolated wind damage would be possible with the strongest storms. ...Northwest... A compact shortwave trough should move through Oregon, favorably timed with peak diurnal heating. Widely scattered to scattered storms will be possible. Temperatures of around -13 to -15 C at 500 mb will support at least low-end buoyancy. The primary uncertainty with regard to severe potential will be the quality of low-level moisture. Most models suggest strong mixing will occur with the NAM being the outlier with low-level moisture. There is additional uncertainty in surface heating given smoke within the region. Confidence in severe storm coverage is too low for probabilities, but strong to marginally severe surface gusts and isolated hail would be possible if greater moisture remains during the afternoon. ..Wendt.. 09/05/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1239 AM CDT Fri Sep 05 2025 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE BORDER AREAS OF TN/MS/AL TO WV/OH... ...SUMMARY... Scattered damaging winds, isolated severe hail, and a brief tornado or two are possible from the Upper Ohio to Tennessee Valleys during the late afternoon and evening. ...Upper OH to TN Valleys... Neutral mid-level height change and initially weak convergence along a slow-moving cold front should delay diurnal convective development. But eastward progression of a low-amplitude impulse, currently over western KS, and strengthening low-level convergence should yield scattered thunderstorms in the late afternoon to early evening. The bulk of strong mid-level flow will largely lag behind the portion of the front that is south of the Upper OH Valley. But with the late day timing of storms, an extensive plume of moderate buoyancy should be prevalent ahead of it. Several multicell clusters and transient supercell structures should develop during the evening within the moderately sheared, southwesterly flow regime. Scattered damaging winds will be the primary hazard, with isolated severe hail and a brief tornado also possible. The severe threat will diminish towards late evening given the extensive overturning and lack of stronger low-level flow/shear to sustain the threat overnight. ...North TX to Mid-South... An elongated mid-level thermal trough, characterized by 500-mb temperatures of -10 to -12 C, will extend into north TX, well to the south of a persistent vertically stacked cyclone over northern ON. Most guidance suggests low to mid-level wind fields will be modest and contain veer-back-veer signatures. Strong speed shear should be mainly confined above 500 mb, coincident with poor upper-level lapse rates atop steeper mid-level lapse rates. Consensus of CAM guidance suggests a messy convective mode should be common as convection increases in the late afternoon and evening, along the more west/east-oriented portion of the surface cold front. Given these factors, have maintained a level 1-MRGL risk for an isolated severe hail/wind threat with a southward shift based on latest guidance. ..Grams/Squitieri.. 09/05/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1239 AM CDT Fri Sep 05 2025 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE BORDER AREAS OF TN/MS/AL TO WV/OH... ...SUMMARY... Scattered damaging winds, isolated severe hail, and a brief tornado or two are possible from the Upper Ohio to Tennessee Valleys during the late afternoon and evening. ...Upper OH to TN Valleys... Neutral mid-level height change and initially weak convergence along a slow-moving cold front should delay diurnal convective development. But eastward progression of a low-amplitude impulse, currently over western KS, and strengthening low-level convergence should yield scattered thunderstorms in the late afternoon to early evening. The bulk of strong mid-level flow will largely lag behind the portion of the front that is south of the Upper OH Valley. But with the late day timing of storms, an extensive plume of moderate buoyancy should be prevalent ahead of it. Several multicell clusters and transient supercell structures should develop during the evening within the moderately sheared, southwesterly flow regime. Scattered damaging winds will be the primary hazard, with isolated severe hail and a brief tornado also possible. The severe threat will diminish towards late evening given the extensive overturning and lack of stronger low-level flow/shear to sustain the threat overnight. ...North TX to Mid-South... An elongated mid-level thermal trough, characterized by 500-mb temperatures of -10 to -12 C, will extend into north TX, well to the south of a persistent vertically stacked cyclone over northern ON. Most guidance suggests low to mid-level wind fields will be modest and contain veer-back-veer signatures. Strong speed shear should be mainly confined above 500 mb, coincident with poor upper-level lapse rates atop steeper mid-level lapse rates. Consensus of CAM guidance suggests a messy convective mode should be common as convection increases in the late afternoon and evening, along the more west/east-oriented portion of the surface cold front. Given these factors, have maintained a level 1-MRGL risk for an isolated severe hail/wind threat with a southward shift based on latest guidance. ..Grams/Squitieri.. 09/05/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1239 AM CDT Fri Sep 05 2025 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE BORDER AREAS OF TN/MS/AL TO WV/OH... ...SUMMARY... Scattered damaging winds, isolated severe hail, and a brief tornado or two are possible from the Upper Ohio to Tennessee Valleys during the late afternoon and evening. ...Upper OH to TN Valleys... Neutral mid-level height change and initially weak convergence along a slow-moving cold front should delay diurnal convective development. But eastward progression of a low-amplitude impulse, currently over western KS, and strengthening low-level convergence should yield scattered thunderstorms in the late afternoon to early evening. The bulk of strong mid-level flow will largely lag behind the portion of the front that is south of the Upper OH Valley. But with the late day timing of storms, an extensive plume of moderate buoyancy should be prevalent ahead of it. Several multicell clusters and transient supercell structures should develop during the evening within the moderately sheared, southwesterly flow regime. Scattered damaging winds will be the primary hazard, with isolated severe hail and a brief tornado also possible. The severe threat will diminish towards late evening given the extensive overturning and lack of stronger low-level flow/shear to sustain the threat overnight. ...North TX to Mid-South... An elongated mid-level thermal trough, characterized by 500-mb temperatures of -10 to -12 C, will extend into north TX, well to the south of a persistent vertically stacked cyclone over northern ON. Most guidance suggests low to mid-level wind fields will be modest and contain veer-back-veer signatures. Strong speed shear should be mainly confined above 500 mb, coincident with poor upper-level lapse rates atop steeper mid-level lapse rates. Consensus of CAM guidance suggests a messy convective mode should be common as convection increases in the late afternoon and evening, along the more west/east-oriented portion of the surface cold front. Given these factors, have maintained a level 1-MRGL risk for an isolated severe hail/wind threat with a southward shift based on latest guidance. ..Grams/Squitieri.. 09/05/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1239 AM CDT Fri Sep 05 2025 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE BORDER AREAS OF TN/MS/AL TO WV/OH... ...SUMMARY... Scattered damaging winds, isolated severe hail, and a brief tornado or two are possible from the Upper Ohio to Tennessee Valleys during the late afternoon and evening. ...Upper OH to TN Valleys... Neutral mid-level height change and initially weak convergence along a slow-moving cold front should delay diurnal convective development. But eastward progression of a low-amplitude impulse, currently over western KS, and strengthening low-level convergence should yield scattered thunderstorms in the late afternoon to early evening. The bulk of strong mid-level flow will largely lag behind the portion of the front that is south of the Upper OH Valley. But with the late day timing of storms, an extensive plume of moderate buoyancy should be prevalent ahead of it. Several multicell clusters and transient supercell structures should develop during the evening within the moderately sheared, southwesterly flow regime. Scattered damaging winds will be the primary hazard, with isolated severe hail and a brief tornado also possible. The severe threat will diminish towards late evening given the extensive overturning and lack of stronger low-level flow/shear to sustain the threat overnight. ...North TX to Mid-South... An elongated mid-level thermal trough, characterized by 500-mb temperatures of -10 to -12 C, will extend into north TX, well to the south of a persistent vertically stacked cyclone over northern ON. Most guidance suggests low to mid-level wind fields will be modest and contain veer-back-veer signatures. Strong speed shear should be mainly confined above 500 mb, coincident with poor upper-level lapse rates atop steeper mid-level lapse rates. Consensus of CAM guidance suggests a messy convective mode should be common as convection increases in the late afternoon and evening, along the more west/east-oriented portion of the surface cold front. Given these factors, have maintained a level 1-MRGL risk for an isolated severe hail/wind threat with a southward shift based on latest guidance. ..Grams/Squitieri.. 09/05/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1239 AM CDT Fri Sep 05 2025 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE BORDER AREAS OF TN/MS/AL TO WV/OH... ...SUMMARY... Scattered damaging winds, isolated severe hail, and a brief tornado or two are possible from the Upper Ohio to Tennessee Valleys during the late afternoon and evening. ...Upper OH to TN Valleys... Neutral mid-level height change and initially weak convergence along a slow-moving cold front should delay diurnal convective development. But eastward progression of a low-amplitude impulse, currently over western KS, and strengthening low-level convergence should yield scattered thunderstorms in the late afternoon to early evening. The bulk of strong mid-level flow will largely lag behind the portion of the front that is south of the Upper OH Valley. But with the late day timing of storms, an extensive plume of moderate buoyancy should be prevalent ahead of it. Several multicell clusters and transient supercell structures should develop during the evening within the moderately sheared, southwesterly flow regime. Scattered damaging winds will be the primary hazard, with isolated severe hail and a brief tornado also possible. The severe threat will diminish towards late evening given the extensive overturning and lack of stronger low-level flow/shear to sustain the threat overnight. ...North TX to Mid-South... An elongated mid-level thermal trough, characterized by 500-mb temperatures of -10 to -12 C, will extend into north TX, well to the south of a persistent vertically stacked cyclone over northern ON. Most guidance suggests low to mid-level wind fields will be modest and contain veer-back-veer signatures. Strong speed shear should be mainly confined above 500 mb, coincident with poor upper-level lapse rates atop steeper mid-level lapse rates. Consensus of CAM guidance suggests a messy convective mode should be common as convection increases in the late afternoon and evening, along the more west/east-oriented portion of the surface cold front. Given these factors, have maintained a level 1-MRGL risk for an isolated severe hail/wind threat with a southward shift based on latest guidance. ..Grams/Squitieri.. 09/05/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1239 AM CDT Fri Sep 05 2025 Valid 051200Z - 061200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE BORDER AREAS OF TN/MS/AL TO WV/OH... ...SUMMARY... Scattered damaging winds, isolated severe hail, and a brief tornado or two are possible from the Upper Ohio to Tennessee Valleys during the late afternoon and evening. ...Upper OH to TN Valleys... Neutral mid-level height change and initially weak convergence along a slow-moving cold front should delay diurnal convective development. But eastward progression of a low-amplitude impulse, currently over western KS, and strengthening low-level convergence should yield scattered thunderstorms in the late afternoon to early evening. The bulk of strong mid-level flow will largely lag behind the portion of the front that is south of the Upper OH Valley. But with the late day timing of storms, an extensive plume of moderate buoyancy should be prevalent ahead of it. Several multicell clusters and transient supercell structures should develop during the evening within the moderately sheared, southwesterly flow regime. Scattered damaging winds will be the primary hazard, with isolated severe hail and a brief tornado also possible. The severe threat will diminish towards late evening given the extensive overturning and lack of stronger low-level flow/shear to sustain the threat overnight. ...North TX to Mid-South... An elongated mid-level thermal trough, characterized by 500-mb temperatures of -10 to -12 C, will extend into north TX, well to the south of a persistent vertically stacked cyclone over northern ON. Most guidance suggests low to mid-level wind fields will be modest and contain veer-back-veer signatures. Strong speed shear should be mainly confined above 500 mb, coincident with poor upper-level lapse rates atop steeper mid-level lapse rates. Consensus of CAM guidance suggests a messy convective mode should be common as convection increases in the late afternoon and evening, along the more west/east-oriented portion of the surface cold front. Given these factors, have maintained a level 1-MRGL risk for an isolated severe hail/wind threat with a southward shift based on latest guidance. ..Grams/Squitieri.. 09/05/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0747 PM CDT Thu Sep 04 2025 Valid 050100Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected tonight. ...Southwest/south-central KS... A sharpening cold front will sweep southward across KS tonight. Mostly elevated convection should increase to the cool side of this undercutting boundary, mainly during the early morning/pre-dawn hours. Initially steep mid-level lapse rates and adequate MUCAPE could support a few storms capable of producing small hail and locally strong gusts amid strengthening low-level northerlies. Overall severe potential still appears fairly low. ..Grams.. 09/05/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0747 PM CDT Thu Sep 04 2025 Valid 050100Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected tonight. ...Southwest/south-central KS... A sharpening cold front will sweep southward across KS tonight. Mostly elevated convection should increase to the cool side of this undercutting boundary, mainly during the early morning/pre-dawn hours. Initially steep mid-level lapse rates and adequate MUCAPE could support a few storms capable of producing small hail and locally strong gusts amid strengthening low-level northerlies. Overall severe potential still appears fairly low. ..Grams.. 09/05/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0747 PM CDT Thu Sep 04 2025 Valid 050100Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected tonight. ...Southwest/south-central KS... A sharpening cold front will sweep southward across KS tonight. Mostly elevated convection should increase to the cool side of this undercutting boundary, mainly during the early morning/pre-dawn hours. Initially steep mid-level lapse rates and adequate MUCAPE could support a few storms capable of producing small hail and locally strong gusts amid strengthening low-level northerlies. Overall severe potential still appears fairly low. ..Grams.. 09/05/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0747 PM CDT Thu Sep 04 2025 Valid 050100Z - 051200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not expected tonight. ...Southwest/south-central KS... A sharpening cold front will sweep southward across KS tonight. Mostly elevated convection should increase to the cool side of this undercutting boundary, mainly during the early morning/pre-dawn hours. Initially steep mid-level lapse rates and adequate MUCAPE could support a few storms capable of producing small hail and locally strong gusts amid strengthening low-level northerlies. Overall severe potential still appears fairly low. ..Grams.. 09/05/2025 Read more

No Mesoscale Discussions are in effect as of Thu Sep 4 23:31:02 UTC 2025.