Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1121 AM CDT Thu Jul 31 2025 Valid 311700Z - 011200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE CENTRAL AND EASTERN GREAT BASIN... No changes to the ongoing forecast. ..Wendt.. 07/31/2025 .PREV DISCUSSION... /ISSUED 0247 AM CDT Thu Jul 31 2025/ ...Synopsis... Broad mid-level troughing will overspread the Interior West today, with multiple mid-level impulses poised to pivot around the trough through the Day 1 period. Upper support with a glancing mid-level impulse will encourage dry and windy conditions across portions of the eastern Great Basin. 20+ mph sustained southwesterly surface winds amid 15 percent RH will overspread dry fuels for several hours during the afternoon, warranting Critical highlights. Mid-level moisture will continue to advect northward across the Pacific Northwest and overspread a relatively dry low-level airmass. High-based thunderstorms will develop during the afternoon and evening hours, with a mix of wet and dry storms possible. Given receptive fuels, isolated dry thunderstorm highlights have been added. ...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 1121 AM CDT Thu Jul 31 2025 Valid 311700Z - 011200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE CENTRAL AND EASTERN GREAT BASIN... No changes to the ongoing forecast. ..Wendt.. 07/31/2025 .PREV DISCUSSION... /ISSUED 0247 AM CDT Thu Jul 31 2025/ ...Synopsis... Broad mid-level troughing will overspread the Interior West today, with multiple mid-level impulses poised to pivot around the trough through the Day 1 period. Upper support with a glancing mid-level impulse will encourage dry and windy conditions across portions of the eastern Great Basin. 20+ mph sustained southwesterly surface winds amid 15 percent RH will overspread dry fuels for several hours during the afternoon, warranting Critical highlights. Mid-level moisture will continue to advect northward across the Pacific Northwest and overspread a relatively dry low-level airmass. High-based thunderstorms will develop during the afternoon and evening hours, with a mix of wet and dry storms possible. Given receptive fuels, isolated dry thunderstorm highlights have been added. ...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 1121 AM CDT Thu Jul 31 2025 Valid 311700Z - 011200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE CENTRAL AND EASTERN GREAT BASIN... No changes to the ongoing forecast. ..Wendt.. 07/31/2025 .PREV DISCUSSION... /ISSUED 0247 AM CDT Thu Jul 31 2025/ ...Synopsis... Broad mid-level troughing will overspread the Interior West today, with multiple mid-level impulses poised to pivot around the trough through the Day 1 period. Upper support with a glancing mid-level impulse will encourage dry and windy conditions across portions of the eastern Great Basin. 20+ mph sustained southwesterly surface winds amid 15 percent RH will overspread dry fuels for several hours during the afternoon, warranting Critical highlights. Mid-level moisture will continue to advect northward across the Pacific Northwest and overspread a relatively dry low-level airmass. High-based thunderstorms will develop during the afternoon and evening hours, with a mix of wet and dry storms possible. Given receptive fuels, isolated dry thunderstorm highlights have been added. ...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 1121 AM CDT Thu Jul 31 2025 Valid 311700Z - 011200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE CENTRAL AND EASTERN GREAT BASIN... No changes to the ongoing forecast. ..Wendt.. 07/31/2025 .PREV DISCUSSION... /ISSUED 0247 AM CDT Thu Jul 31 2025/ ...Synopsis... Broad mid-level troughing will overspread the Interior West today, with multiple mid-level impulses poised to pivot around the trough through the Day 1 period. Upper support with a glancing mid-level impulse will encourage dry and windy conditions across portions of the eastern Great Basin. 20+ mph sustained southwesterly surface winds amid 15 percent RH will overspread dry fuels for several hours during the afternoon, warranting Critical highlights. Mid-level moisture will continue to advect northward across the Pacific Northwest and overspread a relatively dry low-level airmass. High-based thunderstorms will develop during the afternoon and evening hours, with a mix of wet and dry storms possible. Given receptive fuels, isolated dry thunderstorm highlights have been added. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Thu Jul 31 16:24:01 UTC 2025.

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Thu Jul 31 2025 Valid 311630Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-ATLANTIC STATES AND FROM THE COLORADO FRONT RANGE INTO EASTERN AND NORTHERN WYOMING... ...SUMMARY... Severe thunderstorms capable of damaging winds are possible this afternoon and early evening across the Mid-Atlantic region. Other severe wind and hail producing storms are also possible across the central/northern High Plains. ...Mid Atlantic Region... Midday visible-satellite imagery indicates a moist airmass via a swelling cumulus field from the upper OH Valley eastward into the Mid-Atlantic states and Long Island. Additional heating of an extremely moist boundary layer (12 UTC raobs at IAD and WAL showing 17-18 g/kg lowest 100-mb mean mixing ratios), will result in temperatures warming through the 80s deg F with 74-78 dewpoints to the east of the Fall Line. An upstream mid-level shortwave trough over WI/IL will continue to progress eastward towards the region and promote the gradual southward movement of a weak cold front. Despite weak mid-level lapse rates, the aforementioned warming/destabilization through mid afternoon will promote scattered thunderstorms along/ahead of the front. Forecast hodographs will be elongated due to 50-70 kt upper-level flow, which will support storm organization in the form of multicell clusters and possibly a few weak supercell structures. Weak low-level flow and a deep/moisture-rich profile will facilitate water-loaded downdrafts with the stronger cores. Widely scattered 50-65 mph gusts capable of wind damage will be the primary severe concern before much of this activity moves east of the coast by mid evening. ...High Plains... No change from the previous forecast thinking. Weak shortwave ridging will reside across the central Rockies/plains northward into the northern High Plains. Surface observations and satellite data depict a seasonably moist airmass abutted to the Front Range and northward into the eastern WY. Heating over the higher terrain and along a residual frontal zone will aid in scattered storm development this afternoon. The strongest cells will pose some risk of hail and gusty winds over the higher terrain before spreading onto the plains by late afternoon. Forecast soundings in this region show moderately steep mid-level lapse rates, MLCAPE values of 1000-1500 J/kg, and sufficient vertical shear for transient supercell structures. Upscale growth into a linear cluster or two may evolve (supported by recent HREF guidance), and this appears most probable near the WY/CO/NE border during the early evening. A gradual transition from primarily a hail risk to a threat favoring severe gusts may occur as outflow becomes more pervasive as storm coverage and outflow increases during the evening. ...ID/Western MT... A mid-level trough over northern NV will move slowly northward through tonight into the northern Rockies. Forcing for ascent attendant to this upper feature coupled with orographic circulations will likely result in scattered storms developing by mid to late afternoon. Very steep lapse rates and dry sub-cloud layers will promote evaporative cooling and an isolated risk for severe gusts (60-70 mph) with the stronger cores and outflow surges. ...AR/LA... Scattered diurnally driven storms will likely evolve in the vicinity of a weakness in the southern U.S. mid-level anticyclone. A very moist boundary layer amid moderate buoyancy may result in a few stronger water-loaded microbursts capable of 50-65 mph gusts and pockets of wind damage. ..Smith/Thornton.. 07/31/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Thu Jul 31 2025 Valid 311630Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-ATLANTIC STATES AND FROM THE COLORADO FRONT RANGE INTO EASTERN AND NORTHERN WYOMING... ...SUMMARY... Severe thunderstorms capable of damaging winds are possible this afternoon and early evening across the Mid-Atlantic region. Other severe wind and hail producing storms are also possible across the central/northern High Plains. ...Mid Atlantic Region... Midday visible-satellite imagery indicates a moist airmass via a swelling cumulus field from the upper OH Valley eastward into the Mid-Atlantic states and Long Island. Additional heating of an extremely moist boundary layer (12 UTC raobs at IAD and WAL showing 17-18 g/kg lowest 100-mb mean mixing ratios), will result in temperatures warming through the 80s deg F with 74-78 dewpoints to the east of the Fall Line. An upstream mid-level shortwave trough over WI/IL will continue to progress eastward towards the region and promote the gradual southward movement of a weak cold front. Despite weak mid-level lapse rates, the aforementioned warming/destabilization through mid afternoon will promote scattered thunderstorms along/ahead of the front. Forecast hodographs will be elongated due to 50-70 kt upper-level flow, which will support storm organization in the form of multicell clusters and possibly a few weak supercell structures. Weak low-level flow and a deep/moisture-rich profile will facilitate water-loaded downdrafts with the stronger cores. Widely scattered 50-65 mph gusts capable of wind damage will be the primary severe concern before much of this activity moves east of the coast by mid evening. ...High Plains... No change from the previous forecast thinking. Weak shortwave ridging will reside across the central Rockies/plains northward into the northern High Plains. Surface observations and satellite data depict a seasonably moist airmass abutted to the Front Range and northward into the eastern WY. Heating over the higher terrain and along a residual frontal zone will aid in scattered storm development this afternoon. The strongest cells will pose some risk of hail and gusty winds over the higher terrain before spreading onto the plains by late afternoon. Forecast soundings in this region show moderately steep mid-level lapse rates, MLCAPE values of 1000-1500 J/kg, and sufficient vertical shear for transient supercell structures. Upscale growth into a linear cluster or two may evolve (supported by recent HREF guidance), and this appears most probable near the WY/CO/NE border during the early evening. A gradual transition from primarily a hail risk to a threat favoring severe gusts may occur as outflow becomes more pervasive as storm coverage and outflow increases during the evening. ...ID/Western MT... A mid-level trough over northern NV will move slowly northward through tonight into the northern Rockies. Forcing for ascent attendant to this upper feature coupled with orographic circulations will likely result in scattered storms developing by mid to late afternoon. Very steep lapse rates and dry sub-cloud layers will promote evaporative cooling and an isolated risk for severe gusts (60-70 mph) with the stronger cores and outflow surges. ...AR/LA... Scattered diurnally driven storms will likely evolve in the vicinity of a weakness in the southern U.S. mid-level anticyclone. A very moist boundary layer amid moderate buoyancy may result in a few stronger water-loaded microbursts capable of 50-65 mph gusts and pockets of wind damage. ..Smith/Thornton.. 07/31/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Thu Jul 31 2025 Valid 311630Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-ATLANTIC STATES AND FROM THE COLORADO FRONT RANGE INTO EASTERN AND NORTHERN WYOMING... ...SUMMARY... Severe thunderstorms capable of damaging winds are possible this afternoon and early evening across the Mid-Atlantic region. Other severe wind and hail producing storms are also possible across the central/northern High Plains. ...Mid Atlantic Region... Midday visible-satellite imagery indicates a moist airmass via a swelling cumulus field from the upper OH Valley eastward into the Mid-Atlantic states and Long Island. Additional heating of an extremely moist boundary layer (12 UTC raobs at IAD and WAL showing 17-18 g/kg lowest 100-mb mean mixing ratios), will result in temperatures warming through the 80s deg F with 74-78 dewpoints to the east of the Fall Line. An upstream mid-level shortwave trough over WI/IL will continue to progress eastward towards the region and promote the gradual southward movement of a weak cold front. Despite weak mid-level lapse rates, the aforementioned warming/destabilization through mid afternoon will promote scattered thunderstorms along/ahead of the front. Forecast hodographs will be elongated due to 50-70 kt upper-level flow, which will support storm organization in the form of multicell clusters and possibly a few weak supercell structures. Weak low-level flow and a deep/moisture-rich profile will facilitate water-loaded downdrafts with the stronger cores. Widely scattered 50-65 mph gusts capable of wind damage will be the primary severe concern before much of this activity moves east of the coast by mid evening. ...High Plains... No change from the previous forecast thinking. Weak shortwave ridging will reside across the central Rockies/plains northward into the northern High Plains. Surface observations and satellite data depict a seasonably moist airmass abutted to the Front Range and northward into the eastern WY. Heating over the higher terrain and along a residual frontal zone will aid in scattered storm development this afternoon. The strongest cells will pose some risk of hail and gusty winds over the higher terrain before spreading onto the plains by late afternoon. Forecast soundings in this region show moderately steep mid-level lapse rates, MLCAPE values of 1000-1500 J/kg, and sufficient vertical shear for transient supercell structures. Upscale growth into a linear cluster or two may evolve (supported by recent HREF guidance), and this appears most probable near the WY/CO/NE border during the early evening. A gradual transition from primarily a hail risk to a threat favoring severe gusts may occur as outflow becomes more pervasive as storm coverage and outflow increases during the evening. ...ID/Western MT... A mid-level trough over northern NV will move slowly northward through tonight into the northern Rockies. Forcing for ascent attendant to this upper feature coupled with orographic circulations will likely result in scattered storms developing by mid to late afternoon. Very steep lapse rates and dry sub-cloud layers will promote evaporative cooling and an isolated risk for severe gusts (60-70 mph) with the stronger cores and outflow surges. ...AR/LA... Scattered diurnally driven storms will likely evolve in the vicinity of a weakness in the southern U.S. mid-level anticyclone. A very moist boundary layer amid moderate buoyancy may result in a few stronger water-loaded microbursts capable of 50-65 mph gusts and pockets of wind damage. ..Smith/Thornton.. 07/31/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Thu Jul 31 2025 Valid 311630Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-ATLANTIC STATES AND FROM THE COLORADO FRONT RANGE INTO EASTERN AND NORTHERN WYOMING... ...SUMMARY... Severe thunderstorms capable of damaging winds are possible this afternoon and early evening across the Mid-Atlantic region. Other severe wind and hail producing storms are also possible across the central/northern High Plains. ...Mid Atlantic Region... Midday visible-satellite imagery indicates a moist airmass via a swelling cumulus field from the upper OH Valley eastward into the Mid-Atlantic states and Long Island. Additional heating of an extremely moist boundary layer (12 UTC raobs at IAD and WAL showing 17-18 g/kg lowest 100-mb mean mixing ratios), will result in temperatures warming through the 80s deg F with 74-78 dewpoints to the east of the Fall Line. An upstream mid-level shortwave trough over WI/IL will continue to progress eastward towards the region and promote the gradual southward movement of a weak cold front. Despite weak mid-level lapse rates, the aforementioned warming/destabilization through mid afternoon will promote scattered thunderstorms along/ahead of the front. Forecast hodographs will be elongated due to 50-70 kt upper-level flow, which will support storm organization in the form of multicell clusters and possibly a few weak supercell structures. Weak low-level flow and a deep/moisture-rich profile will facilitate water-loaded downdrafts with the stronger cores. Widely scattered 50-65 mph gusts capable of wind damage will be the primary severe concern before much of this activity moves east of the coast by mid evening. ...High Plains... No change from the previous forecast thinking. Weak shortwave ridging will reside across the central Rockies/plains northward into the northern High Plains. Surface observations and satellite data depict a seasonably moist airmass abutted to the Front Range and northward into the eastern WY. Heating over the higher terrain and along a residual frontal zone will aid in scattered storm development this afternoon. The strongest cells will pose some risk of hail and gusty winds over the higher terrain before spreading onto the plains by late afternoon. Forecast soundings in this region show moderately steep mid-level lapse rates, MLCAPE values of 1000-1500 J/kg, and sufficient vertical shear for transient supercell structures. Upscale growth into a linear cluster or two may evolve (supported by recent HREF guidance), and this appears most probable near the WY/CO/NE border during the early evening. A gradual transition from primarily a hail risk to a threat favoring severe gusts may occur as outflow becomes more pervasive as storm coverage and outflow increases during the evening. ...ID/Western MT... A mid-level trough over northern NV will move slowly northward through tonight into the northern Rockies. Forcing for ascent attendant to this upper feature coupled with orographic circulations will likely result in scattered storms developing by mid to late afternoon. Very steep lapse rates and dry sub-cloud layers will promote evaporative cooling and an isolated risk for severe gusts (60-70 mph) with the stronger cores and outflow surges. ...AR/LA... Scattered diurnally driven storms will likely evolve in the vicinity of a weakness in the southern U.S. mid-level anticyclone. A very moist boundary layer amid moderate buoyancy may result in a few stronger water-loaded microbursts capable of 50-65 mph gusts and pockets of wind damage. ..Smith/Thornton.. 07/31/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Thu Jul 31 2025 Valid 311630Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-ATLANTIC STATES AND FROM THE COLORADO FRONT RANGE INTO EASTERN AND NORTHERN WYOMING... ...SUMMARY... Severe thunderstorms capable of damaging winds are possible this afternoon and early evening across the Mid-Atlantic region. Other severe wind and hail producing storms are also possible across the central/northern High Plains. ...Mid Atlantic Region... Midday visible-satellite imagery indicates a moist airmass via a swelling cumulus field from the upper OH Valley eastward into the Mid-Atlantic states and Long Island. Additional heating of an extremely moist boundary layer (12 UTC raobs at IAD and WAL showing 17-18 g/kg lowest 100-mb mean mixing ratios), will result in temperatures warming through the 80s deg F with 74-78 dewpoints to the east of the Fall Line. An upstream mid-level shortwave trough over WI/IL will continue to progress eastward towards the region and promote the gradual southward movement of a weak cold front. Despite weak mid-level lapse rates, the aforementioned warming/destabilization through mid afternoon will promote scattered thunderstorms along/ahead of the front. Forecast hodographs will be elongated due to 50-70 kt upper-level flow, which will support storm organization in the form of multicell clusters and possibly a few weak supercell structures. Weak low-level flow and a deep/moisture-rich profile will facilitate water-loaded downdrafts with the stronger cores. Widely scattered 50-65 mph gusts capable of wind damage will be the primary severe concern before much of this activity moves east of the coast by mid evening. ...High Plains... No change from the previous forecast thinking. Weak shortwave ridging will reside across the central Rockies/plains northward into the northern High Plains. Surface observations and satellite data depict a seasonably moist airmass abutted to the Front Range and northward into the eastern WY. Heating over the higher terrain and along a residual frontal zone will aid in scattered storm development this afternoon. The strongest cells will pose some risk of hail and gusty winds over the higher terrain before spreading onto the plains by late afternoon. Forecast soundings in this region show moderately steep mid-level lapse rates, MLCAPE values of 1000-1500 J/kg, and sufficient vertical shear for transient supercell structures. Upscale growth into a linear cluster or two may evolve (supported by recent HREF guidance), and this appears most probable near the WY/CO/NE border during the early evening. A gradual transition from primarily a hail risk to a threat favoring severe gusts may occur as outflow becomes more pervasive as storm coverage and outflow increases during the evening. ...ID/Western MT... A mid-level trough over northern NV will move slowly northward through tonight into the northern Rockies. Forcing for ascent attendant to this upper feature coupled with orographic circulations will likely result in scattered storms developing by mid to late afternoon. Very steep lapse rates and dry sub-cloud layers will promote evaporative cooling and an isolated risk for severe gusts (60-70 mph) with the stronger cores and outflow surges. ...AR/LA... Scattered diurnally driven storms will likely evolve in the vicinity of a weakness in the southern U.S. mid-level anticyclone. A very moist boundary layer amid moderate buoyancy may result in a few stronger water-loaded microbursts capable of 50-65 mph gusts and pockets of wind damage. ..Smith/Thornton.. 07/31/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Thu Jul 31 2025 Valid 311630Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-ATLANTIC STATES AND FROM THE COLORADO FRONT RANGE INTO EASTERN AND NORTHERN WYOMING... ...SUMMARY... Severe thunderstorms capable of damaging winds are possible this afternoon and early evening across the Mid-Atlantic region. Other severe wind and hail producing storms are also possible across the central/northern High Plains. ...Mid Atlantic Region... Midday visible-satellite imagery indicates a moist airmass via a swelling cumulus field from the upper OH Valley eastward into the Mid-Atlantic states and Long Island. Additional heating of an extremely moist boundary layer (12 UTC raobs at IAD and WAL showing 17-18 g/kg lowest 100-mb mean mixing ratios), will result in temperatures warming through the 80s deg F with 74-78 dewpoints to the east of the Fall Line. An upstream mid-level shortwave trough over WI/IL will continue to progress eastward towards the region and promote the gradual southward movement of a weak cold front. Despite weak mid-level lapse rates, the aforementioned warming/destabilization through mid afternoon will promote scattered thunderstorms along/ahead of the front. Forecast hodographs will be elongated due to 50-70 kt upper-level flow, which will support storm organization in the form of multicell clusters and possibly a few weak supercell structures. Weak low-level flow and a deep/moisture-rich profile will facilitate water-loaded downdrafts with the stronger cores. Widely scattered 50-65 mph gusts capable of wind damage will be the primary severe concern before much of this activity moves east of the coast by mid evening. ...High Plains... No change from the previous forecast thinking. Weak shortwave ridging will reside across the central Rockies/plains northward into the northern High Plains. Surface observations and satellite data depict a seasonably moist airmass abutted to the Front Range and northward into the eastern WY. Heating over the higher terrain and along a residual frontal zone will aid in scattered storm development this afternoon. The strongest cells will pose some risk of hail and gusty winds over the higher terrain before spreading onto the plains by late afternoon. Forecast soundings in this region show moderately steep mid-level lapse rates, MLCAPE values of 1000-1500 J/kg, and sufficient vertical shear for transient supercell structures. Upscale growth into a linear cluster or two may evolve (supported by recent HREF guidance), and this appears most probable near the WY/CO/NE border during the early evening. A gradual transition from primarily a hail risk to a threat favoring severe gusts may occur as outflow becomes more pervasive as storm coverage and outflow increases during the evening. ...ID/Western MT... A mid-level trough over northern NV will move slowly northward through tonight into the northern Rockies. Forcing for ascent attendant to this upper feature coupled with orographic circulations will likely result in scattered storms developing by mid to late afternoon. Very steep lapse rates and dry sub-cloud layers will promote evaporative cooling and an isolated risk for severe gusts (60-70 mph) with the stronger cores and outflow surges. ...AR/LA... Scattered diurnally driven storms will likely evolve in the vicinity of a weakness in the southern U.S. mid-level anticyclone. A very moist boundary layer amid moderate buoyancy may result in a few stronger water-loaded microbursts capable of 50-65 mph gusts and pockets of wind damage. ..Smith/Thornton.. 07/31/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Thu Jul 31 2025 Valid 311630Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-ATLANTIC STATES AND FROM THE COLORADO FRONT RANGE INTO EASTERN AND NORTHERN WYOMING... ...SUMMARY... Severe thunderstorms capable of damaging winds are possible this afternoon and early evening across the Mid-Atlantic region. Other severe wind and hail producing storms are also possible across the central/northern High Plains. ...Mid Atlantic Region... Midday visible-satellite imagery indicates a moist airmass via a swelling cumulus field from the upper OH Valley eastward into the Mid-Atlantic states and Long Island. Additional heating of an extremely moist boundary layer (12 UTC raobs at IAD and WAL showing 17-18 g/kg lowest 100-mb mean mixing ratios), will result in temperatures warming through the 80s deg F with 74-78 dewpoints to the east of the Fall Line. An upstream mid-level shortwave trough over WI/IL will continue to progress eastward towards the region and promote the gradual southward movement of a weak cold front. Despite weak mid-level lapse rates, the aforementioned warming/destabilization through mid afternoon will promote scattered thunderstorms along/ahead of the front. Forecast hodographs will be elongated due to 50-70 kt upper-level flow, which will support storm organization in the form of multicell clusters and possibly a few weak supercell structures. Weak low-level flow and a deep/moisture-rich profile will facilitate water-loaded downdrafts with the stronger cores. Widely scattered 50-65 mph gusts capable of wind damage will be the primary severe concern before much of this activity moves east of the coast by mid evening. ...High Plains... No change from the previous forecast thinking. Weak shortwave ridging will reside across the central Rockies/plains northward into the northern High Plains. Surface observations and satellite data depict a seasonably moist airmass abutted to the Front Range and northward into the eastern WY. Heating over the higher terrain and along a residual frontal zone will aid in scattered storm development this afternoon. The strongest cells will pose some risk of hail and gusty winds over the higher terrain before spreading onto the plains by late afternoon. Forecast soundings in this region show moderately steep mid-level lapse rates, MLCAPE values of 1000-1500 J/kg, and sufficient vertical shear for transient supercell structures. Upscale growth into a linear cluster or two may evolve (supported by recent HREF guidance), and this appears most probable near the WY/CO/NE border during the early evening. A gradual transition from primarily a hail risk to a threat favoring severe gusts may occur as outflow becomes more pervasive as storm coverage and outflow increases during the evening. ...ID/Western MT... A mid-level trough over northern NV will move slowly northward through tonight into the northern Rockies. Forcing for ascent attendant to this upper feature coupled with orographic circulations will likely result in scattered storms developing by mid to late afternoon. Very steep lapse rates and dry sub-cloud layers will promote evaporative cooling and an isolated risk for severe gusts (60-70 mph) with the stronger cores and outflow surges. ...AR/LA... Scattered diurnally driven storms will likely evolve in the vicinity of a weakness in the southern U.S. mid-level anticyclone. A very moist boundary layer amid moderate buoyancy may result in a few stronger water-loaded microbursts capable of 50-65 mph gusts and pockets of wind damage. ..Smith/Thornton.. 07/31/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Thu Jul 31 2025 Valid 311630Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-ATLANTIC STATES AND FROM THE COLORADO FRONT RANGE INTO EASTERN AND NORTHERN WYOMING... ...SUMMARY... Severe thunderstorms capable of damaging winds are possible this afternoon and early evening across the Mid-Atlantic region. Other severe wind and hail producing storms are also possible across the central/northern High Plains. ...Mid Atlantic Region... Midday visible-satellite imagery indicates a moist airmass via a swelling cumulus field from the upper OH Valley eastward into the Mid-Atlantic states and Long Island. Additional heating of an extremely moist boundary layer (12 UTC raobs at IAD and WAL showing 17-18 g/kg lowest 100-mb mean mixing ratios), will result in temperatures warming through the 80s deg F with 74-78 dewpoints to the east of the Fall Line. An upstream mid-level shortwave trough over WI/IL will continue to progress eastward towards the region and promote the gradual southward movement of a weak cold front. Despite weak mid-level lapse rates, the aforementioned warming/destabilization through mid afternoon will promote scattered thunderstorms along/ahead of the front. Forecast hodographs will be elongated due to 50-70 kt upper-level flow, which will support storm organization in the form of multicell clusters and possibly a few weak supercell structures. Weak low-level flow and a deep/moisture-rich profile will facilitate water-loaded downdrafts with the stronger cores. Widely scattered 50-65 mph gusts capable of wind damage will be the primary severe concern before much of this activity moves east of the coast by mid evening. ...High Plains... No change from the previous forecast thinking. Weak shortwave ridging will reside across the central Rockies/plains northward into the northern High Plains. Surface observations and satellite data depict a seasonably moist airmass abutted to the Front Range and northward into the eastern WY. Heating over the higher terrain and along a residual frontal zone will aid in scattered storm development this afternoon. The strongest cells will pose some risk of hail and gusty winds over the higher terrain before spreading onto the plains by late afternoon. Forecast soundings in this region show moderately steep mid-level lapse rates, MLCAPE values of 1000-1500 J/kg, and sufficient vertical shear for transient supercell structures. Upscale growth into a linear cluster or two may evolve (supported by recent HREF guidance), and this appears most probable near the WY/CO/NE border during the early evening. A gradual transition from primarily a hail risk to a threat favoring severe gusts may occur as outflow becomes more pervasive as storm coverage and outflow increases during the evening. ...ID/Western MT... A mid-level trough over northern NV will move slowly northward through tonight into the northern Rockies. Forcing for ascent attendant to this upper feature coupled with orographic circulations will likely result in scattered storms developing by mid to late afternoon. Very steep lapse rates and dry sub-cloud layers will promote evaporative cooling and an isolated risk for severe gusts (60-70 mph) with the stronger cores and outflow surges. ...AR/LA... Scattered diurnally driven storms will likely evolve in the vicinity of a weakness in the southern U.S. mid-level anticyclone. A very moist boundary layer amid moderate buoyancy may result in a few stronger water-loaded microbursts capable of 50-65 mph gusts and pockets of wind damage. ..Smith/Thornton.. 07/31/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Thu Jul 31 2025 Valid 311630Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-ATLANTIC STATES AND FROM THE COLORADO FRONT RANGE INTO EASTERN AND NORTHERN WYOMING... ...SUMMARY... Severe thunderstorms capable of damaging winds are possible this afternoon and early evening across the Mid-Atlantic region. Other severe wind and hail producing storms are also possible across the central/northern High Plains. ...Mid Atlantic Region... Midday visible-satellite imagery indicates a moist airmass via a swelling cumulus field from the upper OH Valley eastward into the Mid-Atlantic states and Long Island. Additional heating of an extremely moist boundary layer (12 UTC raobs at IAD and WAL showing 17-18 g/kg lowest 100-mb mean mixing ratios), will result in temperatures warming through the 80s deg F with 74-78 dewpoints to the east of the Fall Line. An upstream mid-level shortwave trough over WI/IL will continue to progress eastward towards the region and promote the gradual southward movement of a weak cold front. Despite weak mid-level lapse rates, the aforementioned warming/destabilization through mid afternoon will promote scattered thunderstorms along/ahead of the front. Forecast hodographs will be elongated due to 50-70 kt upper-level flow, which will support storm organization in the form of multicell clusters and possibly a few weak supercell structures. Weak low-level flow and a deep/moisture-rich profile will facilitate water-loaded downdrafts with the stronger cores. Widely scattered 50-65 mph gusts capable of wind damage will be the primary severe concern before much of this activity moves east of the coast by mid evening. ...High Plains... No change from the previous forecast thinking. Weak shortwave ridging will reside across the central Rockies/plains northward into the northern High Plains. Surface observations and satellite data depict a seasonably moist airmass abutted to the Front Range and northward into the eastern WY. Heating over the higher terrain and along a residual frontal zone will aid in scattered storm development this afternoon. The strongest cells will pose some risk of hail and gusty winds over the higher terrain before spreading onto the plains by late afternoon. Forecast soundings in this region show moderately steep mid-level lapse rates, MLCAPE values of 1000-1500 J/kg, and sufficient vertical shear for transient supercell structures. Upscale growth into a linear cluster or two may evolve (supported by recent HREF guidance), and this appears most probable near the WY/CO/NE border during the early evening. A gradual transition from primarily a hail risk to a threat favoring severe gusts may occur as outflow becomes more pervasive as storm coverage and outflow increases during the evening. ...ID/Western MT... A mid-level trough over northern NV will move slowly northward through tonight into the northern Rockies. Forcing for ascent attendant to this upper feature coupled with orographic circulations will likely result in scattered storms developing by mid to late afternoon. Very steep lapse rates and dry sub-cloud layers will promote evaporative cooling and an isolated risk for severe gusts (60-70 mph) with the stronger cores and outflow surges. ...AR/LA... Scattered diurnally driven storms will likely evolve in the vicinity of a weakness in the southern U.S. mid-level anticyclone. A very moist boundary layer amid moderate buoyancy may result in a few stronger water-loaded microbursts capable of 50-65 mph gusts and pockets of wind damage. ..Smith/Thornton.. 07/31/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Thu Jul 31 2025 Valid 311630Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-ATLANTIC STATES AND FROM THE COLORADO FRONT RANGE INTO EASTERN AND NORTHERN WYOMING... ...SUMMARY... Severe thunderstorms capable of damaging winds are possible this afternoon and early evening across the Mid-Atlantic region. Other severe wind and hail producing storms are also possible across the central/northern High Plains. ...Mid Atlantic Region... Midday visible-satellite imagery indicates a moist airmass via a swelling cumulus field from the upper OH Valley eastward into the Mid-Atlantic states and Long Island. Additional heating of an extremely moist boundary layer (12 UTC raobs at IAD and WAL showing 17-18 g/kg lowest 100-mb mean mixing ratios), will result in temperatures warming through the 80s deg F with 74-78 dewpoints to the east of the Fall Line. An upstream mid-level shortwave trough over WI/IL will continue to progress eastward towards the region and promote the gradual southward movement of a weak cold front. Despite weak mid-level lapse rates, the aforementioned warming/destabilization through mid afternoon will promote scattered thunderstorms along/ahead of the front. Forecast hodographs will be elongated due to 50-70 kt upper-level flow, which will support storm organization in the form of multicell clusters and possibly a few weak supercell structures. Weak low-level flow and a deep/moisture-rich profile will facilitate water-loaded downdrafts with the stronger cores. Widely scattered 50-65 mph gusts capable of wind damage will be the primary severe concern before much of this activity moves east of the coast by mid evening. ...High Plains... No change from the previous forecast thinking. Weak shortwave ridging will reside across the central Rockies/plains northward into the northern High Plains. Surface observations and satellite data depict a seasonably moist airmass abutted to the Front Range and northward into the eastern WY. Heating over the higher terrain and along a residual frontal zone will aid in scattered storm development this afternoon. The strongest cells will pose some risk of hail and gusty winds over the higher terrain before spreading onto the plains by late afternoon. Forecast soundings in this region show moderately steep mid-level lapse rates, MLCAPE values of 1000-1500 J/kg, and sufficient vertical shear for transient supercell structures. Upscale growth into a linear cluster or two may evolve (supported by recent HREF guidance), and this appears most probable near the WY/CO/NE border during the early evening. A gradual transition from primarily a hail risk to a threat favoring severe gusts may occur as outflow becomes more pervasive as storm coverage and outflow increases during the evening. ...ID/Western MT... A mid-level trough over northern NV will move slowly northward through tonight into the northern Rockies. Forcing for ascent attendant to this upper feature coupled with orographic circulations will likely result in scattered storms developing by mid to late afternoon. Very steep lapse rates and dry sub-cloud layers will promote evaporative cooling and an isolated risk for severe gusts (60-70 mph) with the stronger cores and outflow surges. ...AR/LA... Scattered diurnally driven storms will likely evolve in the vicinity of a weakness in the southern U.S. mid-level anticyclone. A very moist boundary layer amid moderate buoyancy may result in a few stronger water-loaded microbursts capable of 50-65 mph gusts and pockets of wind damage. ..Smith/Thornton.. 07/31/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Thu Jul 31 2025 Valid 311630Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-ATLANTIC STATES AND FROM THE COLORADO FRONT RANGE INTO EASTERN AND NORTHERN WYOMING... ...SUMMARY... Severe thunderstorms capable of damaging winds are possible this afternoon and early evening across the Mid-Atlantic region. Other severe wind and hail producing storms are also possible across the central/northern High Plains. ...Mid Atlantic Region... Midday visible-satellite imagery indicates a moist airmass via a swelling cumulus field from the upper OH Valley eastward into the Mid-Atlantic states and Long Island. Additional heating of an extremely moist boundary layer (12 UTC raobs at IAD and WAL showing 17-18 g/kg lowest 100-mb mean mixing ratios), will result in temperatures warming through the 80s deg F with 74-78 dewpoints to the east of the Fall Line. An upstream mid-level shortwave trough over WI/IL will continue to progress eastward towards the region and promote the gradual southward movement of a weak cold front. Despite weak mid-level lapse rates, the aforementioned warming/destabilization through mid afternoon will promote scattered thunderstorms along/ahead of the front. Forecast hodographs will be elongated due to 50-70 kt upper-level flow, which will support storm organization in the form of multicell clusters and possibly a few weak supercell structures. Weak low-level flow and a deep/moisture-rich profile will facilitate water-loaded downdrafts with the stronger cores. Widely scattered 50-65 mph gusts capable of wind damage will be the primary severe concern before much of this activity moves east of the coast by mid evening. ...High Plains... No change from the previous forecast thinking. Weak shortwave ridging will reside across the central Rockies/plains northward into the northern High Plains. Surface observations and satellite data depict a seasonably moist airmass abutted to the Front Range and northward into the eastern WY. Heating over the higher terrain and along a residual frontal zone will aid in scattered storm development this afternoon. The strongest cells will pose some risk of hail and gusty winds over the higher terrain before spreading onto the plains by late afternoon. Forecast soundings in this region show moderately steep mid-level lapse rates, MLCAPE values of 1000-1500 J/kg, and sufficient vertical shear for transient supercell structures. Upscale growth into a linear cluster or two may evolve (supported by recent HREF guidance), and this appears most probable near the WY/CO/NE border during the early evening. A gradual transition from primarily a hail risk to a threat favoring severe gusts may occur as outflow becomes more pervasive as storm coverage and outflow increases during the evening. ...ID/Western MT... A mid-level trough over northern NV will move slowly northward through tonight into the northern Rockies. Forcing for ascent attendant to this upper feature coupled with orographic circulations will likely result in scattered storms developing by mid to late afternoon. Very steep lapse rates and dry sub-cloud layers will promote evaporative cooling and an isolated risk for severe gusts (60-70 mph) with the stronger cores and outflow surges. ...AR/LA... Scattered diurnally driven storms will likely evolve in the vicinity of a weakness in the southern U.S. mid-level anticyclone. A very moist boundary layer amid moderate buoyancy may result in a few stronger water-loaded microbursts capable of 50-65 mph gusts and pockets of wind damage. ..Smith/Thornton.. 07/31/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Thu Jul 31 2025 Valid 311630Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-ATLANTIC STATES AND FROM THE COLORADO FRONT RANGE INTO EASTERN AND NORTHERN WYOMING... ...SUMMARY... Severe thunderstorms capable of damaging winds are possible this afternoon and early evening across the Mid-Atlantic region. Other severe wind and hail producing storms are also possible across the central/northern High Plains. ...Mid Atlantic Region... Midday visible-satellite imagery indicates a moist airmass via a swelling cumulus field from the upper OH Valley eastward into the Mid-Atlantic states and Long Island. Additional heating of an extremely moist boundary layer (12 UTC raobs at IAD and WAL showing 17-18 g/kg lowest 100-mb mean mixing ratios), will result in temperatures warming through the 80s deg F with 74-78 dewpoints to the east of the Fall Line. An upstream mid-level shortwave trough over WI/IL will continue to progress eastward towards the region and promote the gradual southward movement of a weak cold front. Despite weak mid-level lapse rates, the aforementioned warming/destabilization through mid afternoon will promote scattered thunderstorms along/ahead of the front. Forecast hodographs will be elongated due to 50-70 kt upper-level flow, which will support storm organization in the form of multicell clusters and possibly a few weak supercell structures. Weak low-level flow and a deep/moisture-rich profile will facilitate water-loaded downdrafts with the stronger cores. Widely scattered 50-65 mph gusts capable of wind damage will be the primary severe concern before much of this activity moves east of the coast by mid evening. ...High Plains... No change from the previous forecast thinking. Weak shortwave ridging will reside across the central Rockies/plains northward into the northern High Plains. Surface observations and satellite data depict a seasonably moist airmass abutted to the Front Range and northward into the eastern WY. Heating over the higher terrain and along a residual frontal zone will aid in scattered storm development this afternoon. The strongest cells will pose some risk of hail and gusty winds over the higher terrain before spreading onto the plains by late afternoon. Forecast soundings in this region show moderately steep mid-level lapse rates, MLCAPE values of 1000-1500 J/kg, and sufficient vertical shear for transient supercell structures. Upscale growth into a linear cluster or two may evolve (supported by recent HREF guidance), and this appears most probable near the WY/CO/NE border during the early evening. A gradual transition from primarily a hail risk to a threat favoring severe gusts may occur as outflow becomes more pervasive as storm coverage and outflow increases during the evening. ...ID/Western MT... A mid-level trough over northern NV will move slowly northward through tonight into the northern Rockies. Forcing for ascent attendant to this upper feature coupled with orographic circulations will likely result in scattered storms developing by mid to late afternoon. Very steep lapse rates and dry sub-cloud layers will promote evaporative cooling and an isolated risk for severe gusts (60-70 mph) with the stronger cores and outflow surges. ...AR/LA... Scattered diurnally driven storms will likely evolve in the vicinity of a weakness in the southern U.S. mid-level anticyclone. A very moist boundary layer amid moderate buoyancy may result in a few stronger water-loaded microbursts capable of 50-65 mph gusts and pockets of wind damage. ..Smith/Thornton.. 07/31/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1115 AM CDT Thu Jul 31 2025 Valid 311630Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE MID-ATLANTIC STATES AND FROM THE COLORADO FRONT RANGE INTO EASTERN AND NORTHERN WYOMING... ...SUMMARY... Severe thunderstorms capable of damaging winds are possible this afternoon and early evening across the Mid-Atlantic region. Other severe wind and hail producing storms are also possible across the central/northern High Plains. ...Mid Atlantic Region... Midday visible-satellite imagery indicates a moist airmass via a swelling cumulus field from the upper OH Valley eastward into the Mid-Atlantic states and Long Island. Additional heating of an extremely moist boundary layer (12 UTC raobs at IAD and WAL showing 17-18 g/kg lowest 100-mb mean mixing ratios), will result in temperatures warming through the 80s deg F with 74-78 dewpoints to the east of the Fall Line. An upstream mid-level shortwave trough over WI/IL will continue to progress eastward towards the region and promote the gradual southward movement of a weak cold front. Despite weak mid-level lapse rates, the aforementioned warming/destabilization through mid afternoon will promote scattered thunderstorms along/ahead of the front. Forecast hodographs will be elongated due to 50-70 kt upper-level flow, which will support storm organization in the form of multicell clusters and possibly a few weak supercell structures. Weak low-level flow and a deep/moisture-rich profile will facilitate water-loaded downdrafts with the stronger cores. Widely scattered 50-65 mph gusts capable of wind damage will be the primary severe concern before much of this activity moves east of the coast by mid evening. ...High Plains... No change from the previous forecast thinking. Weak shortwave ridging will reside across the central Rockies/plains northward into the northern High Plains. Surface observations and satellite data depict a seasonably moist airmass abutted to the Front Range and northward into the eastern WY. Heating over the higher terrain and along a residual frontal zone will aid in scattered storm development this afternoon. The strongest cells will pose some risk of hail and gusty winds over the higher terrain before spreading onto the plains by late afternoon. Forecast soundings in this region show moderately steep mid-level lapse rates, MLCAPE values of 1000-1500 J/kg, and sufficient vertical shear for transient supercell structures. Upscale growth into a linear cluster or two may evolve (supported by recent HREF guidance), and this appears most probable near the WY/CO/NE border during the early evening. A gradual transition from primarily a hail risk to a threat favoring severe gusts may occur as outflow becomes more pervasive as storm coverage and outflow increases during the evening. ...ID/Western MT... A mid-level trough over northern NV will move slowly northward through tonight into the northern Rockies. Forcing for ascent attendant to this upper feature coupled with orographic circulations will likely result in scattered storms developing by mid to late afternoon. Very steep lapse rates and dry sub-cloud layers will promote evaporative cooling and an isolated risk for severe gusts (60-70 mph) with the stronger cores and outflow surges. ...AR/LA... Scattered diurnally driven storms will likely evolve in the vicinity of a weakness in the southern U.S. mid-level anticyclone. A very moist boundary layer amid moderate buoyancy may result in a few stronger water-loaded microbursts capable of 50-65 mph gusts and pockets of wind damage. ..Smith/Thornton.. 07/31/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0736 AM CDT Thu Jul 31 2025 Valid 311300Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PORTIONS OF NORTH-CENTRAL COLORADO AND EASTERN WYOMING...AND PARTS OF THE MID ATLANTIC REGION... ...SUMMARY... A few severe storms capable of damaging winds are possible this afternoon across the Mid-Atlantic region. Other severe wind and hail producing storms are also possible across the central/northern High Plains. ...High Plains... A broad upper ridge remains in place across most of the southern US, with a weak trough over the western states. A plume of monsoonal moisture extends from NM into CO/WY/MT, leading to another round of afternoon thunderstorms across the Rockies. The strongest cells will pose some risk of hail and gusty winds over the higher terrain before spreading onto the plains by late afternoon. Forecast soundings in this region show moderately steep mid-level lapse rates, MLCAPE values of 1000-1500 J/kg, and sufficient vertical shear for transient supercell structures. This may be sufficient for widely scattered severe storms capable of large hail and damaging winds. ...Mid Atlantic Region... A weak cold front continues to sag southward across parts of PA and far southern New England this morning. Strong heating to the south of the boundary, coupled with a very moist air mass will lead to moderate afternoon MLCAPE values - despite weak mid-level lapse rates. Scattered thunderstorms are expected to form along/ahead of the front by mid-afternoon. A few severe storms are possible, with locally damaging wind gusts being the main concern. ...ID/Western MT... A shortwave trough is noted in morning water vapor imagery over NV lifting northward. Large scale forcing for ascent ahead of the trough will foster scattered high-based thunderstorms this afternoon across parts of ID and western MT. The strongest cells will be capable of gusty/damaging wind gusts. ..Hart/Grams.. 07/31/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0736 AM CDT Thu Jul 31 2025 Valid 311300Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PORTIONS OF NORTH-CENTRAL COLORADO AND EASTERN WYOMING...AND PARTS OF THE MID ATLANTIC REGION... ...SUMMARY... A few severe storms capable of damaging winds are possible this afternoon across the Mid-Atlantic region. Other severe wind and hail producing storms are also possible across the central/northern High Plains. ...High Plains... A broad upper ridge remains in place across most of the southern US, with a weak trough over the western states. A plume of monsoonal moisture extends from NM into CO/WY/MT, leading to another round of afternoon thunderstorms across the Rockies. The strongest cells will pose some risk of hail and gusty winds over the higher terrain before spreading onto the plains by late afternoon. Forecast soundings in this region show moderately steep mid-level lapse rates, MLCAPE values of 1000-1500 J/kg, and sufficient vertical shear for transient supercell structures. This may be sufficient for widely scattered severe storms capable of large hail and damaging winds. ...Mid Atlantic Region... A weak cold front continues to sag southward across parts of PA and far southern New England this morning. Strong heating to the south of the boundary, coupled with a very moist air mass will lead to moderate afternoon MLCAPE values - despite weak mid-level lapse rates. Scattered thunderstorms are expected to form along/ahead of the front by mid-afternoon. A few severe storms are possible, with locally damaging wind gusts being the main concern. ...ID/Western MT... A shortwave trough is noted in morning water vapor imagery over NV lifting northward. Large scale forcing for ascent ahead of the trough will foster scattered high-based thunderstorms this afternoon across parts of ID and western MT. The strongest cells will be capable of gusty/damaging wind gusts. ..Hart/Grams.. 07/31/2025 Read more