Severe Storms

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0215 PM CDT Sat Jul 26 2025 Valid 281200Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MONTANA...THE DAKOTAS...IOWA...MINNESOTA...AND WISCONSIN... ...SUMMARY... Severe thunderstorms are possible from the northern Rockies into the Dakotas and Upper Midwest. ...Southeast Montana and the Dakotas to Wisconsin... A couple of shortwave impulses are forecast to move eastward through westerly flow aloft on Sunday. At the surface, low pressure is forecast over SD, with a surface front expected to develop south/southeast from southeast MT to the Mid-MO Valley into early Monday. A very moist airmass will be in place ahead of the surface low/front across SD into parts of MN/IA/WI. This will support a broad area of strong to extreme instability. However, uncertainty persists, and is mainly a result of how convection and a potential MCS will develop in the Day 2/Sunday period and what impacts those storms may have on the boundary layer across parts of the Upper Midwest. Nevertheless, it appears likely isolated storms will develop near the surface low and within the post-frontal regime from southeast MT into the Black Hills vicinity. This activity will pose a risk of mainly strong/severe gusts and perhaps some marginal hail. With eastward extent across SD into MN/IA/WI, storms will likely form along the southward-advancing front. Some guidance depicts a modest low-level jet developing during the evening. Coupled with sufficient effective shear, and strong instability, upscale growth into an MCS is possible. Where this may occur is uncertain as previously mentioned outflow from prior convection may result in lingering inhibition. Some severe wind risk appears possible and the Marginal risk (level 1 of 5) will be maintained, though higher probabilities may be needed in subsequent outlooks. ...Central MT... Isolated thunderstorms will develop over higher terrain during the afternoon/evening as a shortwave trough migrates through the upper ridge over the Pacific Northwest. Sufficient moisture will be in place and relatively cool temperatures aloft will aid in MLCAPE values approaching 1000 J/kg. Effective shear magnitudes around 25-30 kt will support occasionally organized cells. A deeply mixed boundary layer will foster locally strong/damaging wind potential. ..Leitman.. 07/26/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0215 PM CDT Sat Jul 26 2025 Valid 281200Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MONTANA...THE DAKOTAS...IOWA...MINNESOTA...AND WISCONSIN... ...SUMMARY... Severe thunderstorms are possible from the northern Rockies into the Dakotas and Upper Midwest. ...Southeast Montana and the Dakotas to Wisconsin... A couple of shortwave impulses are forecast to move eastward through westerly flow aloft on Sunday. At the surface, low pressure is forecast over SD, with a surface front expected to develop south/southeast from southeast MT to the Mid-MO Valley into early Monday. A very moist airmass will be in place ahead of the surface low/front across SD into parts of MN/IA/WI. This will support a broad area of strong to extreme instability. However, uncertainty persists, and is mainly a result of how convection and a potential MCS will develop in the Day 2/Sunday period and what impacts those storms may have on the boundary layer across parts of the Upper Midwest. Nevertheless, it appears likely isolated storms will develop near the surface low and within the post-frontal regime from southeast MT into the Black Hills vicinity. This activity will pose a risk of mainly strong/severe gusts and perhaps some marginal hail. With eastward extent across SD into MN/IA/WI, storms will likely form along the southward-advancing front. Some guidance depicts a modest low-level jet developing during the evening. Coupled with sufficient effective shear, and strong instability, upscale growth into an MCS is possible. Where this may occur is uncertain as previously mentioned outflow from prior convection may result in lingering inhibition. Some severe wind risk appears possible and the Marginal risk (level 1 of 5) will be maintained, though higher probabilities may be needed in subsequent outlooks. ...Central MT... Isolated thunderstorms will develop over higher terrain during the afternoon/evening as a shortwave trough migrates through the upper ridge over the Pacific Northwest. Sufficient moisture will be in place and relatively cool temperatures aloft will aid in MLCAPE values approaching 1000 J/kg. Effective shear magnitudes around 25-30 kt will support occasionally organized cells. A deeply mixed boundary layer will foster locally strong/damaging wind potential. ..Leitman.. 07/26/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0215 PM CDT Sat Jul 26 2025 Valid 281200Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MONTANA...THE DAKOTAS...IOWA...MINNESOTA...AND WISCONSIN... ...SUMMARY... Severe thunderstorms are possible from the northern Rockies into the Dakotas and Upper Midwest. ...Southeast Montana and the Dakotas to Wisconsin... A couple of shortwave impulses are forecast to move eastward through westerly flow aloft on Sunday. At the surface, low pressure is forecast over SD, with a surface front expected to develop south/southeast from southeast MT to the Mid-MO Valley into early Monday. A very moist airmass will be in place ahead of the surface low/front across SD into parts of MN/IA/WI. This will support a broad area of strong to extreme instability. However, uncertainty persists, and is mainly a result of how convection and a potential MCS will develop in the Day 2/Sunday period and what impacts those storms may have on the boundary layer across parts of the Upper Midwest. Nevertheless, it appears likely isolated storms will develop near the surface low and within the post-frontal regime from southeast MT into the Black Hills vicinity. This activity will pose a risk of mainly strong/severe gusts and perhaps some marginal hail. With eastward extent across SD into MN/IA/WI, storms will likely form along the southward-advancing front. Some guidance depicts a modest low-level jet developing during the evening. Coupled with sufficient effective shear, and strong instability, upscale growth into an MCS is possible. Where this may occur is uncertain as previously mentioned outflow from prior convection may result in lingering inhibition. Some severe wind risk appears possible and the Marginal risk (level 1 of 5) will be maintained, though higher probabilities may be needed in subsequent outlooks. ...Central MT... Isolated thunderstorms will develop over higher terrain during the afternoon/evening as a shortwave trough migrates through the upper ridge over the Pacific Northwest. Sufficient moisture will be in place and relatively cool temperatures aloft will aid in MLCAPE values approaching 1000 J/kg. Effective shear magnitudes around 25-30 kt will support occasionally organized cells. A deeply mixed boundary layer will foster locally strong/damaging wind potential. ..Leitman.. 07/26/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0215 PM CDT Sat Jul 26 2025 Valid 281200Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MONTANA...THE DAKOTAS...IOWA...MINNESOTA...AND WISCONSIN... ...SUMMARY... Severe thunderstorms are possible from the northern Rockies into the Dakotas and Upper Midwest. ...Southeast Montana and the Dakotas to Wisconsin... A couple of shortwave impulses are forecast to move eastward through westerly flow aloft on Sunday. At the surface, low pressure is forecast over SD, with a surface front expected to develop south/southeast from southeast MT to the Mid-MO Valley into early Monday. A very moist airmass will be in place ahead of the surface low/front across SD into parts of MN/IA/WI. This will support a broad area of strong to extreme instability. However, uncertainty persists, and is mainly a result of how convection and a potential MCS will develop in the Day 2/Sunday period and what impacts those storms may have on the boundary layer across parts of the Upper Midwest. Nevertheless, it appears likely isolated storms will develop near the surface low and within the post-frontal regime from southeast MT into the Black Hills vicinity. This activity will pose a risk of mainly strong/severe gusts and perhaps some marginal hail. With eastward extent across SD into MN/IA/WI, storms will likely form along the southward-advancing front. Some guidance depicts a modest low-level jet developing during the evening. Coupled with sufficient effective shear, and strong instability, upscale growth into an MCS is possible. Where this may occur is uncertain as previously mentioned outflow from prior convection may result in lingering inhibition. Some severe wind risk appears possible and the Marginal risk (level 1 of 5) will be maintained, though higher probabilities may be needed in subsequent outlooks. ...Central MT... Isolated thunderstorms will develop over higher terrain during the afternoon/evening as a shortwave trough migrates through the upper ridge over the Pacific Northwest. Sufficient moisture will be in place and relatively cool temperatures aloft will aid in MLCAPE values approaching 1000 J/kg. Effective shear magnitudes around 25-30 kt will support occasionally organized cells. A deeply mixed boundary layer will foster locally strong/damaging wind potential. ..Leitman.. 07/26/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0215 PM CDT Sat Jul 26 2025 Valid 281200Z - 291200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MONTANA...THE DAKOTAS...IOWA...MINNESOTA...AND WISCONSIN... ...SUMMARY... Severe thunderstorms are possible from the northern Rockies into the Dakotas and Upper Midwest. ...Southeast Montana and the Dakotas to Wisconsin... A couple of shortwave impulses are forecast to move eastward through westerly flow aloft on Sunday. At the surface, low pressure is forecast over SD, with a surface front expected to develop south/southeast from southeast MT to the Mid-MO Valley into early Monday. A very moist airmass will be in place ahead of the surface low/front across SD into parts of MN/IA/WI. This will support a broad area of strong to extreme instability. However, uncertainty persists, and is mainly a result of how convection and a potential MCS will develop in the Day 2/Sunday period and what impacts those storms may have on the boundary layer across parts of the Upper Midwest. Nevertheless, it appears likely isolated storms will develop near the surface low and within the post-frontal regime from southeast MT into the Black Hills vicinity. This activity will pose a risk of mainly strong/severe gusts and perhaps some marginal hail. With eastward extent across SD into MN/IA/WI, storms will likely form along the southward-advancing front. Some guidance depicts a modest low-level jet developing during the evening. Coupled with sufficient effective shear, and strong instability, upscale growth into an MCS is possible. Where this may occur is uncertain as previously mentioned outflow from prior convection may result in lingering inhibition. Some severe wind risk appears possible and the Marginal risk (level 1 of 5) will be maintained, though higher probabilities may be needed in subsequent outlooks. ...Central MT... Isolated thunderstorms will develop over higher terrain during the afternoon/evening as a shortwave trough migrates through the upper ridge over the Pacific Northwest. Sufficient moisture will be in place and relatively cool temperatures aloft will aid in MLCAPE values approaching 1000 J/kg. Effective shear magnitudes around 25-30 kt will support occasionally organized cells. A deeply mixed boundary layer will foster locally strong/damaging wind potential. ..Leitman.. 07/26/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Sat Jul 26 2025 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MN...WI...AND UPPER MI... ...SUMMARY... Severe thunderstorms are possible across the Upper Midwest, as well as across portions of the Mid-Atlantic and New England region. ...Upper Midwest... Uncertainty still exists for Sunday's forecast, driven by convection in the Day 1/Saturday period persisting into parts of MN early in the forecast period. However, forecast guidance is consistent in bringing an upper shortwave trough across MN/WI/Upper MI, with 40-60 kt 500 mb westerly flow overspreading the region coincident with the shortwave feature. At the surface, a very moist airmass will be in place with dewpoints mostly in the 70s. This will support a corridor of strong to extreme instability (MLCAPE 3000-5000 J/kg from western SD into MN and portions of northern WI/Upper MI). A weak surface front/trough will develop east/southeast through the period and may intersect outflow from morning activity. This should focus thunderstorm develop/re-intensification as the airmass rapidly destabilizes/recovers ahead of or in the wake of any lingering early morning thunderstorm activity. While the spatial extent of greater severe potential remains a bit uncertain, the best consistency across multiple forecast models suggests severe/damaging wind potential will be greater across parts of MN/northern WI and parts of Upper MI. A Slight risk (level 2 of 5) has been included to account for latest trends in guidance and an overall favorable synoptic/mesoscale pattern for an organized line of convection producing damaging gusts. Convection may persist downstream during the evening/nighttime hours into IA/IL/southern WI, but uncertainty is greater in these areas, so the Marginal risk (level 1 of 5) has been maintained. ...Mid-Atlantic Vicinity... A couple of shortwave impulses are expected to move through northwesterly flow aloft across the Mid-Atlantic vicinity Sunday morning/afternoon. Deep shear will remain weak, with only around 15-25 kt northwesterly flow depicted in forecast soundings. Nevertheless, a very moist airmass with dewpoints in the 70s and PW values over 2 inches, will be in place across the region. This will support strong instability in the 2000-3000 J/kg MLCAPE range. Where strong heating occurs, steepening low-level lapse rates are noted in forecast soundings. Thunderstorms are expected to develop over higher terrain as a weak surface boundary sags southward. Additional convection may develop along a surface trough across the VA/NC Piedmont. Isolated strong/damaging gusts associated with wet downbursts will be possible as storms develop south/southeast through early evening. ..Leitman.. 07/26/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Sat Jul 26 2025 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MN...WI...AND UPPER MI... ...SUMMARY... Severe thunderstorms are possible across the Upper Midwest, as well as across portions of the Mid-Atlantic and New England region. ...Upper Midwest... Uncertainty still exists for Sunday's forecast, driven by convection in the Day 1/Saturday period persisting into parts of MN early in the forecast period. However, forecast guidance is consistent in bringing an upper shortwave trough across MN/WI/Upper MI, with 40-60 kt 500 mb westerly flow overspreading the region coincident with the shortwave feature. At the surface, a very moist airmass will be in place with dewpoints mostly in the 70s. This will support a corridor of strong to extreme instability (MLCAPE 3000-5000 J/kg from western SD into MN and portions of northern WI/Upper MI). A weak surface front/trough will develop east/southeast through the period and may intersect outflow from morning activity. This should focus thunderstorm develop/re-intensification as the airmass rapidly destabilizes/recovers ahead of or in the wake of any lingering early morning thunderstorm activity. While the spatial extent of greater severe potential remains a bit uncertain, the best consistency across multiple forecast models suggests severe/damaging wind potential will be greater across parts of MN/northern WI and parts of Upper MI. A Slight risk (level 2 of 5) has been included to account for latest trends in guidance and an overall favorable synoptic/mesoscale pattern for an organized line of convection producing damaging gusts. Convection may persist downstream during the evening/nighttime hours into IA/IL/southern WI, but uncertainty is greater in these areas, so the Marginal risk (level 1 of 5) has been maintained. ...Mid-Atlantic Vicinity... A couple of shortwave impulses are expected to move through northwesterly flow aloft across the Mid-Atlantic vicinity Sunday morning/afternoon. Deep shear will remain weak, with only around 15-25 kt northwesterly flow depicted in forecast soundings. Nevertheless, a very moist airmass with dewpoints in the 70s and PW values over 2 inches, will be in place across the region. This will support strong instability in the 2000-3000 J/kg MLCAPE range. Where strong heating occurs, steepening low-level lapse rates are noted in forecast soundings. Thunderstorms are expected to develop over higher terrain as a weak surface boundary sags southward. Additional convection may develop along a surface trough across the VA/NC Piedmont. Isolated strong/damaging gusts associated with wet downbursts will be possible as storms develop south/southeast through early evening. ..Leitman.. 07/26/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Sat Jul 26 2025 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MN...WI...AND UPPER MI... ...SUMMARY... Severe thunderstorms are possible across the Upper Midwest, as well as across portions of the Mid-Atlantic and New England region. ...Upper Midwest... Uncertainty still exists for Sunday's forecast, driven by convection in the Day 1/Saturday period persisting into parts of MN early in the forecast period. However, forecast guidance is consistent in bringing an upper shortwave trough across MN/WI/Upper MI, with 40-60 kt 500 mb westerly flow overspreading the region coincident with the shortwave feature. At the surface, a very moist airmass will be in place with dewpoints mostly in the 70s. This will support a corridor of strong to extreme instability (MLCAPE 3000-5000 J/kg from western SD into MN and portions of northern WI/Upper MI). A weak surface front/trough will develop east/southeast through the period and may intersect outflow from morning activity. This should focus thunderstorm develop/re-intensification as the airmass rapidly destabilizes/recovers ahead of or in the wake of any lingering early morning thunderstorm activity. While the spatial extent of greater severe potential remains a bit uncertain, the best consistency across multiple forecast models suggests severe/damaging wind potential will be greater across parts of MN/northern WI and parts of Upper MI. A Slight risk (level 2 of 5) has been included to account for latest trends in guidance and an overall favorable synoptic/mesoscale pattern for an organized line of convection producing damaging gusts. Convection may persist downstream during the evening/nighttime hours into IA/IL/southern WI, but uncertainty is greater in these areas, so the Marginal risk (level 1 of 5) has been maintained. ...Mid-Atlantic Vicinity... A couple of shortwave impulses are expected to move through northwesterly flow aloft across the Mid-Atlantic vicinity Sunday morning/afternoon. Deep shear will remain weak, with only around 15-25 kt northwesterly flow depicted in forecast soundings. Nevertheless, a very moist airmass with dewpoints in the 70s and PW values over 2 inches, will be in place across the region. This will support strong instability in the 2000-3000 J/kg MLCAPE range. Where strong heating occurs, steepening low-level lapse rates are noted in forecast soundings. Thunderstorms are expected to develop over higher terrain as a weak surface boundary sags southward. Additional convection may develop along a surface trough across the VA/NC Piedmont. Isolated strong/damaging gusts associated with wet downbursts will be possible as storms develop south/southeast through early evening. ..Leitman.. 07/26/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Sat Jul 26 2025 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MN...WI...AND UPPER MI... ...SUMMARY... Severe thunderstorms are possible across the Upper Midwest, as well as across portions of the Mid-Atlantic and New England region. ...Upper Midwest... Uncertainty still exists for Sunday's forecast, driven by convection in the Day 1/Saturday period persisting into parts of MN early in the forecast period. However, forecast guidance is consistent in bringing an upper shortwave trough across MN/WI/Upper MI, with 40-60 kt 500 mb westerly flow overspreading the region coincident with the shortwave feature. At the surface, a very moist airmass will be in place with dewpoints mostly in the 70s. This will support a corridor of strong to extreme instability (MLCAPE 3000-5000 J/kg from western SD into MN and portions of northern WI/Upper MI). A weak surface front/trough will develop east/southeast through the period and may intersect outflow from morning activity. This should focus thunderstorm develop/re-intensification as the airmass rapidly destabilizes/recovers ahead of or in the wake of any lingering early morning thunderstorm activity. While the spatial extent of greater severe potential remains a bit uncertain, the best consistency across multiple forecast models suggests severe/damaging wind potential will be greater across parts of MN/northern WI and parts of Upper MI. A Slight risk (level 2 of 5) has been included to account for latest trends in guidance and an overall favorable synoptic/mesoscale pattern for an organized line of convection producing damaging gusts. Convection may persist downstream during the evening/nighttime hours into IA/IL/southern WI, but uncertainty is greater in these areas, so the Marginal risk (level 1 of 5) has been maintained. ...Mid-Atlantic Vicinity... A couple of shortwave impulses are expected to move through northwesterly flow aloft across the Mid-Atlantic vicinity Sunday morning/afternoon. Deep shear will remain weak, with only around 15-25 kt northwesterly flow depicted in forecast soundings. Nevertheless, a very moist airmass with dewpoints in the 70s and PW values over 2 inches, will be in place across the region. This will support strong instability in the 2000-3000 J/kg MLCAPE range. Where strong heating occurs, steepening low-level lapse rates are noted in forecast soundings. Thunderstorms are expected to develop over higher terrain as a weak surface boundary sags southward. Additional convection may develop along a surface trough across the VA/NC Piedmont. Isolated strong/damaging gusts associated with wet downbursts will be possible as storms develop south/southeast through early evening. ..Leitman.. 07/26/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Sat Jul 26 2025 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MN...WI...AND UPPER MI... ...SUMMARY... Severe thunderstorms are possible across the Upper Midwest, as well as across portions of the Mid-Atlantic and New England region. ...Upper Midwest... Uncertainty still exists for Sunday's forecast, driven by convection in the Day 1/Saturday period persisting into parts of MN early in the forecast period. However, forecast guidance is consistent in bringing an upper shortwave trough across MN/WI/Upper MI, with 40-60 kt 500 mb westerly flow overspreading the region coincident with the shortwave feature. At the surface, a very moist airmass will be in place with dewpoints mostly in the 70s. This will support a corridor of strong to extreme instability (MLCAPE 3000-5000 J/kg from western SD into MN and portions of northern WI/Upper MI). A weak surface front/trough will develop east/southeast through the period and may intersect outflow from morning activity. This should focus thunderstorm develop/re-intensification as the airmass rapidly destabilizes/recovers ahead of or in the wake of any lingering early morning thunderstorm activity. While the spatial extent of greater severe potential remains a bit uncertain, the best consistency across multiple forecast models suggests severe/damaging wind potential will be greater across parts of MN/northern WI and parts of Upper MI. A Slight risk (level 2 of 5) has been included to account for latest trends in guidance and an overall favorable synoptic/mesoscale pattern for an organized line of convection producing damaging gusts. Convection may persist downstream during the evening/nighttime hours into IA/IL/southern WI, but uncertainty is greater in these areas, so the Marginal risk (level 1 of 5) has been maintained. ...Mid-Atlantic Vicinity... A couple of shortwave impulses are expected to move through northwesterly flow aloft across the Mid-Atlantic vicinity Sunday morning/afternoon. Deep shear will remain weak, with only around 15-25 kt northwesterly flow depicted in forecast soundings. Nevertheless, a very moist airmass with dewpoints in the 70s and PW values over 2 inches, will be in place across the region. This will support strong instability in the 2000-3000 J/kg MLCAPE range. Where strong heating occurs, steepening low-level lapse rates are noted in forecast soundings. Thunderstorms are expected to develop over higher terrain as a weak surface boundary sags southward. Additional convection may develop along a surface trough across the VA/NC Piedmont. Isolated strong/damaging gusts associated with wet downbursts will be possible as storms develop south/southeast through early evening. ..Leitman.. 07/26/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Sat Jul 26 2025 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MN...WI...AND UPPER MI... ...SUMMARY... Severe thunderstorms are possible across the Upper Midwest, as well as across portions of the Mid-Atlantic and New England region. ...Upper Midwest... Uncertainty still exists for Sunday's forecast, driven by convection in the Day 1/Saturday period persisting into parts of MN early in the forecast period. However, forecast guidance is consistent in bringing an upper shortwave trough across MN/WI/Upper MI, with 40-60 kt 500 mb westerly flow overspreading the region coincident with the shortwave feature. At the surface, a very moist airmass will be in place with dewpoints mostly in the 70s. This will support a corridor of strong to extreme instability (MLCAPE 3000-5000 J/kg from western SD into MN and portions of northern WI/Upper MI). A weak surface front/trough will develop east/southeast through the period and may intersect outflow from morning activity. This should focus thunderstorm develop/re-intensification as the airmass rapidly destabilizes/recovers ahead of or in the wake of any lingering early morning thunderstorm activity. While the spatial extent of greater severe potential remains a bit uncertain, the best consistency across multiple forecast models suggests severe/damaging wind potential will be greater across parts of MN/northern WI and parts of Upper MI. A Slight risk (level 2 of 5) has been included to account for latest trends in guidance and an overall favorable synoptic/mesoscale pattern for an organized line of convection producing damaging gusts. Convection may persist downstream during the evening/nighttime hours into IA/IL/southern WI, but uncertainty is greater in these areas, so the Marginal risk (level 1 of 5) has been maintained. ...Mid-Atlantic Vicinity... A couple of shortwave impulses are expected to move through northwesterly flow aloft across the Mid-Atlantic vicinity Sunday morning/afternoon. Deep shear will remain weak, with only around 15-25 kt northwesterly flow depicted in forecast soundings. Nevertheless, a very moist airmass with dewpoints in the 70s and PW values over 2 inches, will be in place across the region. This will support strong instability in the 2000-3000 J/kg MLCAPE range. Where strong heating occurs, steepening low-level lapse rates are noted in forecast soundings. Thunderstorms are expected to develop over higher terrain as a weak surface boundary sags southward. Additional convection may develop along a surface trough across the VA/NC Piedmont. Isolated strong/damaging gusts associated with wet downbursts will be possible as storms develop south/southeast through early evening. ..Leitman.. 07/26/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Sat Jul 26 2025 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MN...WI...AND UPPER MI... ...SUMMARY... Severe thunderstorms are possible across the Upper Midwest, as well as across portions of the Mid-Atlantic and New England region. ...Upper Midwest... Uncertainty still exists for Sunday's forecast, driven by convection in the Day 1/Saturday period persisting into parts of MN early in the forecast period. However, forecast guidance is consistent in bringing an upper shortwave trough across MN/WI/Upper MI, with 40-60 kt 500 mb westerly flow overspreading the region coincident with the shortwave feature. At the surface, a very moist airmass will be in place with dewpoints mostly in the 70s. This will support a corridor of strong to extreme instability (MLCAPE 3000-5000 J/kg from western SD into MN and portions of northern WI/Upper MI). A weak surface front/trough will develop east/southeast through the period and may intersect outflow from morning activity. This should focus thunderstorm develop/re-intensification as the airmass rapidly destabilizes/recovers ahead of or in the wake of any lingering early morning thunderstorm activity. While the spatial extent of greater severe potential remains a bit uncertain, the best consistency across multiple forecast models suggests severe/damaging wind potential will be greater across parts of MN/northern WI and parts of Upper MI. A Slight risk (level 2 of 5) has been included to account for latest trends in guidance and an overall favorable synoptic/mesoscale pattern for an organized line of convection producing damaging gusts. Convection may persist downstream during the evening/nighttime hours into IA/IL/southern WI, but uncertainty is greater in these areas, so the Marginal risk (level 1 of 5) has been maintained. ...Mid-Atlantic Vicinity... A couple of shortwave impulses are expected to move through northwesterly flow aloft across the Mid-Atlantic vicinity Sunday morning/afternoon. Deep shear will remain weak, with only around 15-25 kt northwesterly flow depicted in forecast soundings. Nevertheless, a very moist airmass with dewpoints in the 70s and PW values over 2 inches, will be in place across the region. This will support strong instability in the 2000-3000 J/kg MLCAPE range. Where strong heating occurs, steepening low-level lapse rates are noted in forecast soundings. Thunderstorms are expected to develop over higher terrain as a weak surface boundary sags southward. Additional convection may develop along a surface trough across the VA/NC Piedmont. Isolated strong/damaging gusts associated with wet downbursts will be possible as storms develop south/southeast through early evening. ..Leitman.. 07/26/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Sat Jul 26 2025 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MN...WI...AND UPPER MI... ...SUMMARY... Severe thunderstorms are possible across the Upper Midwest, as well as across portions of the Mid-Atlantic and New England region. ...Upper Midwest... Uncertainty still exists for Sunday's forecast, driven by convection in the Day 1/Saturday period persisting into parts of MN early in the forecast period. However, forecast guidance is consistent in bringing an upper shortwave trough across MN/WI/Upper MI, with 40-60 kt 500 mb westerly flow overspreading the region coincident with the shortwave feature. At the surface, a very moist airmass will be in place with dewpoints mostly in the 70s. This will support a corridor of strong to extreme instability (MLCAPE 3000-5000 J/kg from western SD into MN and portions of northern WI/Upper MI). A weak surface front/trough will develop east/southeast through the period and may intersect outflow from morning activity. This should focus thunderstorm develop/re-intensification as the airmass rapidly destabilizes/recovers ahead of or in the wake of any lingering early morning thunderstorm activity. While the spatial extent of greater severe potential remains a bit uncertain, the best consistency across multiple forecast models suggests severe/damaging wind potential will be greater across parts of MN/northern WI and parts of Upper MI. A Slight risk (level 2 of 5) has been included to account for latest trends in guidance and an overall favorable synoptic/mesoscale pattern for an organized line of convection producing damaging gusts. Convection may persist downstream during the evening/nighttime hours into IA/IL/southern WI, but uncertainty is greater in these areas, so the Marginal risk (level 1 of 5) has been maintained. ...Mid-Atlantic Vicinity... A couple of shortwave impulses are expected to move through northwesterly flow aloft across the Mid-Atlantic vicinity Sunday morning/afternoon. Deep shear will remain weak, with only around 15-25 kt northwesterly flow depicted in forecast soundings. Nevertheless, a very moist airmass with dewpoints in the 70s and PW values over 2 inches, will be in place across the region. This will support strong instability in the 2000-3000 J/kg MLCAPE range. Where strong heating occurs, steepening low-level lapse rates are noted in forecast soundings. Thunderstorms are expected to develop over higher terrain as a weak surface boundary sags southward. Additional convection may develop along a surface trough across the VA/NC Piedmont. Isolated strong/damaging gusts associated with wet downbursts will be possible as storms develop south/southeast through early evening. ..Leitman.. 07/26/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Sat Jul 26 2025 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MN...WI...AND UPPER MI... ...SUMMARY... Severe thunderstorms are possible across the Upper Midwest, as well as across portions of the Mid-Atlantic and New England region. ...Upper Midwest... Uncertainty still exists for Sunday's forecast, driven by convection in the Day 1/Saturday period persisting into parts of MN early in the forecast period. However, forecast guidance is consistent in bringing an upper shortwave trough across MN/WI/Upper MI, with 40-60 kt 500 mb westerly flow overspreading the region coincident with the shortwave feature. At the surface, a very moist airmass will be in place with dewpoints mostly in the 70s. This will support a corridor of strong to extreme instability (MLCAPE 3000-5000 J/kg from western SD into MN and portions of northern WI/Upper MI). A weak surface front/trough will develop east/southeast through the period and may intersect outflow from morning activity. This should focus thunderstorm develop/re-intensification as the airmass rapidly destabilizes/recovers ahead of or in the wake of any lingering early morning thunderstorm activity. While the spatial extent of greater severe potential remains a bit uncertain, the best consistency across multiple forecast models suggests severe/damaging wind potential will be greater across parts of MN/northern WI and parts of Upper MI. A Slight risk (level 2 of 5) has been included to account for latest trends in guidance and an overall favorable synoptic/mesoscale pattern for an organized line of convection producing damaging gusts. Convection may persist downstream during the evening/nighttime hours into IA/IL/southern WI, but uncertainty is greater in these areas, so the Marginal risk (level 1 of 5) has been maintained. ...Mid-Atlantic Vicinity... A couple of shortwave impulses are expected to move through northwesterly flow aloft across the Mid-Atlantic vicinity Sunday morning/afternoon. Deep shear will remain weak, with only around 15-25 kt northwesterly flow depicted in forecast soundings. Nevertheless, a very moist airmass with dewpoints in the 70s and PW values over 2 inches, will be in place across the region. This will support strong instability in the 2000-3000 J/kg MLCAPE range. Where strong heating occurs, steepening low-level lapse rates are noted in forecast soundings. Thunderstorms are expected to develop over higher terrain as a weak surface boundary sags southward. Additional convection may develop along a surface trough across the VA/NC Piedmont. Isolated strong/damaging gusts associated with wet downbursts will be possible as storms develop south/southeast through early evening. ..Leitman.. 07/26/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1232 PM CDT Sat Jul 26 2025 Valid 271200Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF MN...WI...AND UPPER MI... ...SUMMARY... Severe thunderstorms are possible across the Upper Midwest, as well as across portions of the Mid-Atlantic and New England region. ...Upper Midwest... Uncertainty still exists for Sunday's forecast, driven by convection in the Day 1/Saturday period persisting into parts of MN early in the forecast period. However, forecast guidance is consistent in bringing an upper shortwave trough across MN/WI/Upper MI, with 40-60 kt 500 mb westerly flow overspreading the region coincident with the shortwave feature. At the surface, a very moist airmass will be in place with dewpoints mostly in the 70s. This will support a corridor of strong to extreme instability (MLCAPE 3000-5000 J/kg from western SD into MN and portions of northern WI/Upper MI). A weak surface front/trough will develop east/southeast through the period and may intersect outflow from morning activity. This should focus thunderstorm develop/re-intensification as the airmass rapidly destabilizes/recovers ahead of or in the wake of any lingering early morning thunderstorm activity. While the spatial extent of greater severe potential remains a bit uncertain, the best consistency across multiple forecast models suggests severe/damaging wind potential will be greater across parts of MN/northern WI and parts of Upper MI. A Slight risk (level 2 of 5) has been included to account for latest trends in guidance and an overall favorable synoptic/mesoscale pattern for an organized line of convection producing damaging gusts. Convection may persist downstream during the evening/nighttime hours into IA/IL/southern WI, but uncertainty is greater in these areas, so the Marginal risk (level 1 of 5) has been maintained. ...Mid-Atlantic Vicinity... A couple of shortwave impulses are expected to move through northwesterly flow aloft across the Mid-Atlantic vicinity Sunday morning/afternoon. Deep shear will remain weak, with only around 15-25 kt northwesterly flow depicted in forecast soundings. Nevertheless, a very moist airmass with dewpoints in the 70s and PW values over 2 inches, will be in place across the region. This will support strong instability in the 2000-3000 J/kg MLCAPE range. Where strong heating occurs, steepening low-level lapse rates are noted in forecast soundings. Thunderstorms are expected to develop over higher terrain as a weak surface boundary sags southward. Additional convection may develop along a surface trough across the VA/NC Piedmont. Isolated strong/damaging gusts associated with wet downbursts will be possible as storms develop south/southeast through early evening. ..Leitman.. 07/26/2025 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1152 AM CDT Sat Jul 26 2025 Valid 261700Z - 271200Z ...17z Update... The prior forecast remains valid with minor adjustments for the most recent guidance. Scattered thunderstorms, with isolated dry strikes, remain likely over portions of the northern Great Basin and northern Rockies this afternoon/evening. The edges of the IsoDryT area have been adjusted for recent heavier precipitation. Additional scattered storms are possible into parts of southwestern MT supporting some risk for lightning ignitions. Across the eastern Great Basin and Western Slope, dry/breezy conditions with RH below 15% and winds greater than 15 mph are likely this afternoon and evening from UT/AZ into parts of CO/WY. Minor adjustments were made to areas where recent rainfall has limited fuel availability. Otherwise, see the prior discussion for more information. ..Lyons.. 07/26/2025 .PREV DISCUSSION... /ISSUED 0138 AM CDT Sat Jul 26 2025/ ...Synopsis... A broad upper trough will overspread much of the western U.S. while upper ridging persists east of the Rockies today. Multiple embedded mid-level impulses will traverse the northern Great Basin into the northern Rockies during the afternoon, encouraging dry and breezy conditions across parts of the Great Basin into the Four Corners region, as well as thunderstorm development into the Pacific Northwest. By afternoon peak heating, southwesterly sustained surface winds will reach 15-25 mph as RH dips to 10-20 percent across the eastern Great Basin/Four Corners. Elevated highlights have been maintained given the presence of dry fuels. Farther to the northwest, from Northeast California to the Idaho/Montana border, adequate mid-level moisture and deep-layer ascent will support isolated to scattered thunderstorm development atop a dry boundary layer. High-based thunderstorms will produce a mix of wet and dry strikes atop receptive fuels, warranting the continuation of isolated dry thunderstorm highlights. ...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 1152 AM CDT Sat Jul 26 2025 Valid 261700Z - 271200Z ...17z Update... The prior forecast remains valid with minor adjustments for the most recent guidance. Scattered thunderstorms, with isolated dry strikes, remain likely over portions of the northern Great Basin and northern Rockies this afternoon/evening. The edges of the IsoDryT area have been adjusted for recent heavier precipitation. Additional scattered storms are possible into parts of southwestern MT supporting some risk for lightning ignitions. Across the eastern Great Basin and Western Slope, dry/breezy conditions with RH below 15% and winds greater than 15 mph are likely this afternoon and evening from UT/AZ into parts of CO/WY. Minor adjustments were made to areas where recent rainfall has limited fuel availability. Otherwise, see the prior discussion for more information. ..Lyons.. 07/26/2025 .PREV DISCUSSION... /ISSUED 0138 AM CDT Sat Jul 26 2025/ ...Synopsis... A broad upper trough will overspread much of the western U.S. while upper ridging persists east of the Rockies today. Multiple embedded mid-level impulses will traverse the northern Great Basin into the northern Rockies during the afternoon, encouraging dry and breezy conditions across parts of the Great Basin into the Four Corners region, as well as thunderstorm development into the Pacific Northwest. By afternoon peak heating, southwesterly sustained surface winds will reach 15-25 mph as RH dips to 10-20 percent across the eastern Great Basin/Four Corners. Elevated highlights have been maintained given the presence of dry fuels. Farther to the northwest, from Northeast California to the Idaho/Montana border, adequate mid-level moisture and deep-layer ascent will support isolated to scattered thunderstorm development atop a dry boundary layer. High-based thunderstorms will produce a mix of wet and dry strikes atop receptive fuels, warranting the continuation of isolated dry thunderstorm highlights. ...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 1152 AM CDT Sat Jul 26 2025 Valid 261700Z - 271200Z ...17z Update... The prior forecast remains valid with minor adjustments for the most recent guidance. Scattered thunderstorms, with isolated dry strikes, remain likely over portions of the northern Great Basin and northern Rockies this afternoon/evening. The edges of the IsoDryT area have been adjusted for recent heavier precipitation. Additional scattered storms are possible into parts of southwestern MT supporting some risk for lightning ignitions. Across the eastern Great Basin and Western Slope, dry/breezy conditions with RH below 15% and winds greater than 15 mph are likely this afternoon and evening from UT/AZ into parts of CO/WY. Minor adjustments were made to areas where recent rainfall has limited fuel availability. Otherwise, see the prior discussion for more information. ..Lyons.. 07/26/2025 .PREV DISCUSSION... /ISSUED 0138 AM CDT Sat Jul 26 2025/ ...Synopsis... A broad upper trough will overspread much of the western U.S. while upper ridging persists east of the Rockies today. Multiple embedded mid-level impulses will traverse the northern Great Basin into the northern Rockies during the afternoon, encouraging dry and breezy conditions across parts of the Great Basin into the Four Corners region, as well as thunderstorm development into the Pacific Northwest. By afternoon peak heating, southwesterly sustained surface winds will reach 15-25 mph as RH dips to 10-20 percent across the eastern Great Basin/Four Corners. Elevated highlights have been maintained given the presence of dry fuels. Farther to the northwest, from Northeast California to the Idaho/Montana border, adequate mid-level moisture and deep-layer ascent will support isolated to scattered thunderstorm development atop a dry boundary layer. High-based thunderstorms will produce a mix of wet and dry strikes atop receptive fuels, warranting the continuation of isolated dry thunderstorm highlights. ...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 1152 AM CDT Sat Jul 26 2025 Valid 261700Z - 271200Z ...17z Update... The prior forecast remains valid with minor adjustments for the most recent guidance. Scattered thunderstorms, with isolated dry strikes, remain likely over portions of the northern Great Basin and northern Rockies this afternoon/evening. The edges of the IsoDryT area have been adjusted for recent heavier precipitation. Additional scattered storms are possible into parts of southwestern MT supporting some risk for lightning ignitions. Across the eastern Great Basin and Western Slope, dry/breezy conditions with RH below 15% and winds greater than 15 mph are likely this afternoon and evening from UT/AZ into parts of CO/WY. Minor adjustments were made to areas where recent rainfall has limited fuel availability. Otherwise, see the prior discussion for more information. ..Lyons.. 07/26/2025 .PREV DISCUSSION... /ISSUED 0138 AM CDT Sat Jul 26 2025/ ...Synopsis... A broad upper trough will overspread much of the western U.S. while upper ridging persists east of the Rockies today. Multiple embedded mid-level impulses will traverse the northern Great Basin into the northern Rockies during the afternoon, encouraging dry and breezy conditions across parts of the Great Basin into the Four Corners region, as well as thunderstorm development into the Pacific Northwest. By afternoon peak heating, southwesterly sustained surface winds will reach 15-25 mph as RH dips to 10-20 percent across the eastern Great Basin/Four Corners. Elevated highlights have been maintained given the presence of dry fuels. Farther to the northwest, from Northeast California to the Idaho/Montana border, adequate mid-level moisture and deep-layer ascent will support isolated to scattered thunderstorm development atop a dry boundary layer. High-based thunderstorms will produce a mix of wet and dry strikes atop receptive fuels, warranting the continuation of isolated dry thunderstorm highlights. ...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 1152 AM CDT Sat Jul 26 2025 Valid 261700Z - 271200Z ...17z Update... The prior forecast remains valid with minor adjustments for the most recent guidance. Scattered thunderstorms, with isolated dry strikes, remain likely over portions of the northern Great Basin and northern Rockies this afternoon/evening. The edges of the IsoDryT area have been adjusted for recent heavier precipitation. Additional scattered storms are possible into parts of southwestern MT supporting some risk for lightning ignitions. Across the eastern Great Basin and Western Slope, dry/breezy conditions with RH below 15% and winds greater than 15 mph are likely this afternoon and evening from UT/AZ into parts of CO/WY. Minor adjustments were made to areas where recent rainfall has limited fuel availability. Otherwise, see the prior discussion for more information. ..Lyons.. 07/26/2025 .PREV DISCUSSION... /ISSUED 0138 AM CDT Sat Jul 26 2025/ ...Synopsis... A broad upper trough will overspread much of the western U.S. while upper ridging persists east of the Rockies today. Multiple embedded mid-level impulses will traverse the northern Great Basin into the northern Rockies during the afternoon, encouraging dry and breezy conditions across parts of the Great Basin into the Four Corners region, as well as thunderstorm development into the Pacific Northwest. By afternoon peak heating, southwesterly sustained surface winds will reach 15-25 mph as RH dips to 10-20 percent across the eastern Great Basin/Four Corners. Elevated highlights have been maintained given the presence of dry fuels. Farther to the northwest, from Northeast California to the Idaho/Montana border, adequate mid-level moisture and deep-layer ascent will support isolated to scattered thunderstorm development atop a dry boundary layer. High-based thunderstorms will produce a mix of wet and dry strikes atop receptive fuels, warranting the continuation of isolated dry thunderstorm highlights. ...Please see www.spc.noaa.gov/fire for graphic product... Read more