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SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Mon Apr 28 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHERN MINNESOTA...NORTHERN IOWA...AND WESTERN WISCONSIN... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest later today into tonight, with a regional severe weather outbreak possible. The most dangerous period is likely during the late afternoon and evening when strong tornado potential should be maximized. Scattered large to very large hail and damaging winds are likely as well. ...Synopsis... A positively tilted mid/upper-level shortwave trough, with several embedded vorticity maxima, will move east-northeast through the day across the Great Plains and Upper Midwest. The southwest portion of the large-scale trough and an embedded midlevel cyclone will remain in place near the Four Corners through most of the period. A strong midlevel jet (70+ kt at 500 mb) will move from the central Plains toward the upper Midwest/Great Lakes later today into this evening. The primary surface cyclone will move from the eastern Dakotas toward the upper Great Lakes, as a trailing cold front moves through parts of the Great Plains and eventually the Upper Midwest. By late afternoon, a dryline will extend from near the MN/IA border southwestward into the southern High Plains. ...Upper Midwest... A regional severe weather outbreak still appears possible across the Upper Midwest, with a threat of strong tornadoes, very large hail, and swaths of damaging winds. No major changes have been made to the Moderate and Enhanced Risk areas. Extensive elevated convection and a possible MCS will likely be ongoing at the start of the forecast period across parts of ND/MN, and may tend to redevelop through the day. This could slow the northward advance of the warm front to some extent, but 60s F dewpoints are expected reach at least central MN into northern WI by mid/late afternoon. South of the warm front and east of the dryline, the environment is expected to become increasingly volatile through the afternoon, with strong instability (MLCAPE near/above 3000 J/kg) and deep-layer shear, and a persistently intense low-level jet that will maintain very favorable low-level shear/SRH. This environment will be conditionally favorable for long-track supercells with strong/intense tornado potential. Uncertainty remains regarding the evolution of diurnal convection across the warm sector. Guidance generally suggests that surface-based storms will develop near the surface low and along the prefrontal trough/dryline across southern MN, which could evolve quickly into a cluster or linear mode, though the environment would still support embedded supercell potential with all severe hazards possible. If development in this area is able to remain semi-discrete, then a couple long-track tornadic supercells could occur. Farther south into IA, stronger heating/mixing is expected near the dryline, though large-scale ascent and low-level convergence may be somewhat weaker compared to areas farther north. While guidance varies regarding the potential for development across IA during the afternoon, any supercell that can initiate and be sustained could become long-tracked within the expanding and very favorable warm sector, posing a threat for strong to intense tornadoes and very large hail. As the surface low and related boundaries move eastward, organized convection may develop in place and/or spread into parts of WI, with a threat of all severe hazards and some strong-tornado potential. Farther west, a couple of supercells may develop in the region between the prefrontal trough/dryline and cold front, and pose a threat of large hail and locally damaging gusts as they move across northeast NE/southeast SD into parts of MN/IA. ...Parts of KS/MO into the Southern Plains... While large-scale ascent will be comparatively weaker from KS/MO into the southern Plains, isolated to widely scattered storm development will be possible within a weakly capped environment. Instability and deep-layer shear will both be moderate to strong by late afternoon into the evening, and a few supercells may develop near the dryline. Large to very large hail and locally damaging winds will likely be the initial primary hazard, but increasing low-level SRH by early evening will result in some tornado threat as well. Additional strong to locally severe storm development will be possible overnight near the advancing cold front, aided by a continued nocturnal strengthening of the low-level jet. ..Dean/Weinman.. 04/28/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Mon Apr 28 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHERN MINNESOTA...NORTHERN IOWA...AND WESTERN WISCONSIN... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest later today into tonight, with a regional severe weather outbreak possible. The most dangerous period is likely during the late afternoon and evening when strong tornado potential should be maximized. Scattered large to very large hail and damaging winds are likely as well. ...Synopsis... A positively tilted mid/upper-level shortwave trough, with several embedded vorticity maxima, will move east-northeast through the day across the Great Plains and Upper Midwest. The southwest portion of the large-scale trough and an embedded midlevel cyclone will remain in place near the Four Corners through most of the period. A strong midlevel jet (70+ kt at 500 mb) will move from the central Plains toward the upper Midwest/Great Lakes later today into this evening. The primary surface cyclone will move from the eastern Dakotas toward the upper Great Lakes, as a trailing cold front moves through parts of the Great Plains and eventually the Upper Midwest. By late afternoon, a dryline will extend from near the MN/IA border southwestward into the southern High Plains. ...Upper Midwest... A regional severe weather outbreak still appears possible across the Upper Midwest, with a threat of strong tornadoes, very large hail, and swaths of damaging winds. No major changes have been made to the Moderate and Enhanced Risk areas. Extensive elevated convection and a possible MCS will likely be ongoing at the start of the forecast period across parts of ND/MN, and may tend to redevelop through the day. This could slow the northward advance of the warm front to some extent, but 60s F dewpoints are expected reach at least central MN into northern WI by mid/late afternoon. South of the warm front and east of the dryline, the environment is expected to become increasingly volatile through the afternoon, with strong instability (MLCAPE near/above 3000 J/kg) and deep-layer shear, and a persistently intense low-level jet that will maintain very favorable low-level shear/SRH. This environment will be conditionally favorable for long-track supercells with strong/intense tornado potential. Uncertainty remains regarding the evolution of diurnal convection across the warm sector. Guidance generally suggests that surface-based storms will develop near the surface low and along the prefrontal trough/dryline across southern MN, which could evolve quickly into a cluster or linear mode, though the environment would still support embedded supercell potential with all severe hazards possible. If development in this area is able to remain semi-discrete, then a couple long-track tornadic supercells could occur. Farther south into IA, stronger heating/mixing is expected near the dryline, though large-scale ascent and low-level convergence may be somewhat weaker compared to areas farther north. While guidance varies regarding the potential for development across IA during the afternoon, any supercell that can initiate and be sustained could become long-tracked within the expanding and very favorable warm sector, posing a threat for strong to intense tornadoes and very large hail. As the surface low and related boundaries move eastward, organized convection may develop in place and/or spread into parts of WI, with a threat of all severe hazards and some strong-tornado potential. Farther west, a couple of supercells may develop in the region between the prefrontal trough/dryline and cold front, and pose a threat of large hail and locally damaging gusts as they move across northeast NE/southeast SD into parts of MN/IA. ...Parts of KS/MO into the Southern Plains... While large-scale ascent will be comparatively weaker from KS/MO into the southern Plains, isolated to widely scattered storm development will be possible within a weakly capped environment. Instability and deep-layer shear will both be moderate to strong by late afternoon into the evening, and a few supercells may develop near the dryline. Large to very large hail and locally damaging winds will likely be the initial primary hazard, but increasing low-level SRH by early evening will result in some tornado threat as well. Additional strong to locally severe storm development will be possible overnight near the advancing cold front, aided by a continued nocturnal strengthening of the low-level jet. ..Dean/Weinman.. 04/28/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Mon Apr 28 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHERN MINNESOTA...NORTHERN IOWA...AND WESTERN WISCONSIN... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest later today into tonight, with a regional severe weather outbreak possible. The most dangerous period is likely during the late afternoon and evening when strong tornado potential should be maximized. Scattered large to very large hail and damaging winds are likely as well. ...Synopsis... A positively tilted mid/upper-level shortwave trough, with several embedded vorticity maxima, will move east-northeast through the day across the Great Plains and Upper Midwest. The southwest portion of the large-scale trough and an embedded midlevel cyclone will remain in place near the Four Corners through most of the period. A strong midlevel jet (70+ kt at 500 mb) will move from the central Plains toward the upper Midwest/Great Lakes later today into this evening. The primary surface cyclone will move from the eastern Dakotas toward the upper Great Lakes, as a trailing cold front moves through parts of the Great Plains and eventually the Upper Midwest. By late afternoon, a dryline will extend from near the MN/IA border southwestward into the southern High Plains. ...Upper Midwest... A regional severe weather outbreak still appears possible across the Upper Midwest, with a threat of strong tornadoes, very large hail, and swaths of damaging winds. No major changes have been made to the Moderate and Enhanced Risk areas. Extensive elevated convection and a possible MCS will likely be ongoing at the start of the forecast period across parts of ND/MN, and may tend to redevelop through the day. This could slow the northward advance of the warm front to some extent, but 60s F dewpoints are expected reach at least central MN into northern WI by mid/late afternoon. South of the warm front and east of the dryline, the environment is expected to become increasingly volatile through the afternoon, with strong instability (MLCAPE near/above 3000 J/kg) and deep-layer shear, and a persistently intense low-level jet that will maintain very favorable low-level shear/SRH. This environment will be conditionally favorable for long-track supercells with strong/intense tornado potential. Uncertainty remains regarding the evolution of diurnal convection across the warm sector. Guidance generally suggests that surface-based storms will develop near the surface low and along the prefrontal trough/dryline across southern MN, which could evolve quickly into a cluster or linear mode, though the environment would still support embedded supercell potential with all severe hazards possible. If development in this area is able to remain semi-discrete, then a couple long-track tornadic supercells could occur. Farther south into IA, stronger heating/mixing is expected near the dryline, though large-scale ascent and low-level convergence may be somewhat weaker compared to areas farther north. While guidance varies regarding the potential for development across IA during the afternoon, any supercell that can initiate and be sustained could become long-tracked within the expanding and very favorable warm sector, posing a threat for strong to intense tornadoes and very large hail. As the surface low and related boundaries move eastward, organized convection may develop in place and/or spread into parts of WI, with a threat of all severe hazards and some strong-tornado potential. Farther west, a couple of supercells may develop in the region between the prefrontal trough/dryline and cold front, and pose a threat of large hail and locally damaging gusts as they move across northeast NE/southeast SD into parts of MN/IA. ...Parts of KS/MO into the Southern Plains... While large-scale ascent will be comparatively weaker from KS/MO into the southern Plains, isolated to widely scattered storm development will be possible within a weakly capped environment. Instability and deep-layer shear will both be moderate to strong by late afternoon into the evening, and a few supercells may develop near the dryline. Large to very large hail and locally damaging winds will likely be the initial primary hazard, but increasing low-level SRH by early evening will result in some tornado threat as well. Additional strong to locally severe storm development will be possible overnight near the advancing cold front, aided by a continued nocturnal strengthening of the low-level jet. ..Dean/Weinman.. 04/28/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Mon Apr 28 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHERN MINNESOTA...NORTHERN IOWA...AND WESTERN WISCONSIN... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest later today into tonight, with a regional severe weather outbreak possible. The most dangerous period is likely during the late afternoon and evening when strong tornado potential should be maximized. Scattered large to very large hail and damaging winds are likely as well. ...Synopsis... A positively tilted mid/upper-level shortwave trough, with several embedded vorticity maxima, will move east-northeast through the day across the Great Plains and Upper Midwest. The southwest portion of the large-scale trough and an embedded midlevel cyclone will remain in place near the Four Corners through most of the period. A strong midlevel jet (70+ kt at 500 mb) will move from the central Plains toward the upper Midwest/Great Lakes later today into this evening. The primary surface cyclone will move from the eastern Dakotas toward the upper Great Lakes, as a trailing cold front moves through parts of the Great Plains and eventually the Upper Midwest. By late afternoon, a dryline will extend from near the MN/IA border southwestward into the southern High Plains. ...Upper Midwest... A regional severe weather outbreak still appears possible across the Upper Midwest, with a threat of strong tornadoes, very large hail, and swaths of damaging winds. No major changes have been made to the Moderate and Enhanced Risk areas. Extensive elevated convection and a possible MCS will likely be ongoing at the start of the forecast period across parts of ND/MN, and may tend to redevelop through the day. This could slow the northward advance of the warm front to some extent, but 60s F dewpoints are expected reach at least central MN into northern WI by mid/late afternoon. South of the warm front and east of the dryline, the environment is expected to become increasingly volatile through the afternoon, with strong instability (MLCAPE near/above 3000 J/kg) and deep-layer shear, and a persistently intense low-level jet that will maintain very favorable low-level shear/SRH. This environment will be conditionally favorable for long-track supercells with strong/intense tornado potential. Uncertainty remains regarding the evolution of diurnal convection across the warm sector. Guidance generally suggests that surface-based storms will develop near the surface low and along the prefrontal trough/dryline across southern MN, which could evolve quickly into a cluster or linear mode, though the environment would still support embedded supercell potential with all severe hazards possible. If development in this area is able to remain semi-discrete, then a couple long-track tornadic supercells could occur. Farther south into IA, stronger heating/mixing is expected near the dryline, though large-scale ascent and low-level convergence may be somewhat weaker compared to areas farther north. While guidance varies regarding the potential for development across IA during the afternoon, any supercell that can initiate and be sustained could become long-tracked within the expanding and very favorable warm sector, posing a threat for strong to intense tornadoes and very large hail. As the surface low and related boundaries move eastward, organized convection may develop in place and/or spread into parts of WI, with a threat of all severe hazards and some strong-tornado potential. Farther west, a couple of supercells may develop in the region between the prefrontal trough/dryline and cold front, and pose a threat of large hail and locally damaging gusts as they move across northeast NE/southeast SD into parts of MN/IA. ...Parts of KS/MO into the Southern Plains... While large-scale ascent will be comparatively weaker from KS/MO into the southern Plains, isolated to widely scattered storm development will be possible within a weakly capped environment. Instability and deep-layer shear will both be moderate to strong by late afternoon into the evening, and a few supercells may develop near the dryline. Large to very large hail and locally damaging winds will likely be the initial primary hazard, but increasing low-level SRH by early evening will result in some tornado threat as well. Additional strong to locally severe storm development will be possible overnight near the advancing cold front, aided by a continued nocturnal strengthening of the low-level jet. ..Dean/Weinman.. 04/28/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Mon Apr 28 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHERN MINNESOTA...NORTHERN IOWA...AND WESTERN WISCONSIN... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest later today into tonight, with a regional severe weather outbreak possible. The most dangerous period is likely during the late afternoon and evening when strong tornado potential should be maximized. Scattered large to very large hail and damaging winds are likely as well. ...Synopsis... A positively tilted mid/upper-level shortwave trough, with several embedded vorticity maxima, will move east-northeast through the day across the Great Plains and Upper Midwest. The southwest portion of the large-scale trough and an embedded midlevel cyclone will remain in place near the Four Corners through most of the period. A strong midlevel jet (70+ kt at 500 mb) will move from the central Plains toward the upper Midwest/Great Lakes later today into this evening. The primary surface cyclone will move from the eastern Dakotas toward the upper Great Lakes, as a trailing cold front moves through parts of the Great Plains and eventually the Upper Midwest. By late afternoon, a dryline will extend from near the MN/IA border southwestward into the southern High Plains. ...Upper Midwest... A regional severe weather outbreak still appears possible across the Upper Midwest, with a threat of strong tornadoes, very large hail, and swaths of damaging winds. No major changes have been made to the Moderate and Enhanced Risk areas. Extensive elevated convection and a possible MCS will likely be ongoing at the start of the forecast period across parts of ND/MN, and may tend to redevelop through the day. This could slow the northward advance of the warm front to some extent, but 60s F dewpoints are expected reach at least central MN into northern WI by mid/late afternoon. South of the warm front and east of the dryline, the environment is expected to become increasingly volatile through the afternoon, with strong instability (MLCAPE near/above 3000 J/kg) and deep-layer shear, and a persistently intense low-level jet that will maintain very favorable low-level shear/SRH. This environment will be conditionally favorable for long-track supercells with strong/intense tornado potential. Uncertainty remains regarding the evolution of diurnal convection across the warm sector. Guidance generally suggests that surface-based storms will develop near the surface low and along the prefrontal trough/dryline across southern MN, which could evolve quickly into a cluster or linear mode, though the environment would still support embedded supercell potential with all severe hazards possible. If development in this area is able to remain semi-discrete, then a couple long-track tornadic supercells could occur. Farther south into IA, stronger heating/mixing is expected near the dryline, though large-scale ascent and low-level convergence may be somewhat weaker compared to areas farther north. While guidance varies regarding the potential for development across IA during the afternoon, any supercell that can initiate and be sustained could become long-tracked within the expanding and very favorable warm sector, posing a threat for strong to intense tornadoes and very large hail. As the surface low and related boundaries move eastward, organized convection may develop in place and/or spread into parts of WI, with a threat of all severe hazards and some strong-tornado potential. Farther west, a couple of supercells may develop in the region between the prefrontal trough/dryline and cold front, and pose a threat of large hail and locally damaging gusts as they move across northeast NE/southeast SD into parts of MN/IA. ...Parts of KS/MO into the Southern Plains... While large-scale ascent will be comparatively weaker from KS/MO into the southern Plains, isolated to widely scattered storm development will be possible within a weakly capped environment. Instability and deep-layer shear will both be moderate to strong by late afternoon into the evening, and a few supercells may develop near the dryline. Large to very large hail and locally damaging winds will likely be the initial primary hazard, but increasing low-level SRH by early evening will result in some tornado threat as well. Additional strong to locally severe storm development will be possible overnight near the advancing cold front, aided by a continued nocturnal strengthening of the low-level jet. ..Dean/Weinman.. 04/28/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Mon Apr 28 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHERN MINNESOTA...NORTHERN IOWA...AND WESTERN WISCONSIN... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest later today into tonight, with a regional severe weather outbreak possible. The most dangerous period is likely during the late afternoon and evening when strong tornado potential should be maximized. Scattered large to very large hail and damaging winds are likely as well. ...Synopsis... A positively tilted mid/upper-level shortwave trough, with several embedded vorticity maxima, will move east-northeast through the day across the Great Plains and Upper Midwest. The southwest portion of the large-scale trough and an embedded midlevel cyclone will remain in place near the Four Corners through most of the period. A strong midlevel jet (70+ kt at 500 mb) will move from the central Plains toward the upper Midwest/Great Lakes later today into this evening. The primary surface cyclone will move from the eastern Dakotas toward the upper Great Lakes, as a trailing cold front moves through parts of the Great Plains and eventually the Upper Midwest. By late afternoon, a dryline will extend from near the MN/IA border southwestward into the southern High Plains. ...Upper Midwest... A regional severe weather outbreak still appears possible across the Upper Midwest, with a threat of strong tornadoes, very large hail, and swaths of damaging winds. No major changes have been made to the Moderate and Enhanced Risk areas. Extensive elevated convection and a possible MCS will likely be ongoing at the start of the forecast period across parts of ND/MN, and may tend to redevelop through the day. This could slow the northward advance of the warm front to some extent, but 60s F dewpoints are expected reach at least central MN into northern WI by mid/late afternoon. South of the warm front and east of the dryline, the environment is expected to become increasingly volatile through the afternoon, with strong instability (MLCAPE near/above 3000 J/kg) and deep-layer shear, and a persistently intense low-level jet that will maintain very favorable low-level shear/SRH. This environment will be conditionally favorable for long-track supercells with strong/intense tornado potential. Uncertainty remains regarding the evolution of diurnal convection across the warm sector. Guidance generally suggests that surface-based storms will develop near the surface low and along the prefrontal trough/dryline across southern MN, which could evolve quickly into a cluster or linear mode, though the environment would still support embedded supercell potential with all severe hazards possible. If development in this area is able to remain semi-discrete, then a couple long-track tornadic supercells could occur. Farther south into IA, stronger heating/mixing is expected near the dryline, though large-scale ascent and low-level convergence may be somewhat weaker compared to areas farther north. While guidance varies regarding the potential for development across IA during the afternoon, any supercell that can initiate and be sustained could become long-tracked within the expanding and very favorable warm sector, posing a threat for strong to intense tornadoes and very large hail. As the surface low and related boundaries move eastward, organized convection may develop in place and/or spread into parts of WI, with a threat of all severe hazards and some strong-tornado potential. Farther west, a couple of supercells may develop in the region between the prefrontal trough/dryline and cold front, and pose a threat of large hail and locally damaging gusts as they move across northeast NE/southeast SD into parts of MN/IA. ...Parts of KS/MO into the Southern Plains... While large-scale ascent will be comparatively weaker from KS/MO into the southern Plains, isolated to widely scattered storm development will be possible within a weakly capped environment. Instability and deep-layer shear will both be moderate to strong by late afternoon into the evening, and a few supercells may develop near the dryline. Large to very large hail and locally damaging winds will likely be the initial primary hazard, but increasing low-level SRH by early evening will result in some tornado threat as well. Additional strong to locally severe storm development will be possible overnight near the advancing cold front, aided by a continued nocturnal strengthening of the low-level jet. ..Dean/Weinman.. 04/28/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Mon Apr 28 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHERN MINNESOTA...NORTHERN IOWA...AND WESTERN WISCONSIN... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest later today into tonight, with a regional severe weather outbreak possible. The most dangerous period is likely during the late afternoon and evening when strong tornado potential should be maximized. Scattered large to very large hail and damaging winds are likely as well. ...Synopsis... A positively tilted mid/upper-level shortwave trough, with several embedded vorticity maxima, will move east-northeast through the day across the Great Plains and Upper Midwest. The southwest portion of the large-scale trough and an embedded midlevel cyclone will remain in place near the Four Corners through most of the period. A strong midlevel jet (70+ kt at 500 mb) will move from the central Plains toward the upper Midwest/Great Lakes later today into this evening. The primary surface cyclone will move from the eastern Dakotas toward the upper Great Lakes, as a trailing cold front moves through parts of the Great Plains and eventually the Upper Midwest. By late afternoon, a dryline will extend from near the MN/IA border southwestward into the southern High Plains. ...Upper Midwest... A regional severe weather outbreak still appears possible across the Upper Midwest, with a threat of strong tornadoes, very large hail, and swaths of damaging winds. No major changes have been made to the Moderate and Enhanced Risk areas. Extensive elevated convection and a possible MCS will likely be ongoing at the start of the forecast period across parts of ND/MN, and may tend to redevelop through the day. This could slow the northward advance of the warm front to some extent, but 60s F dewpoints are expected reach at least central MN into northern WI by mid/late afternoon. South of the warm front and east of the dryline, the environment is expected to become increasingly volatile through the afternoon, with strong instability (MLCAPE near/above 3000 J/kg) and deep-layer shear, and a persistently intense low-level jet that will maintain very favorable low-level shear/SRH. This environment will be conditionally favorable for long-track supercells with strong/intense tornado potential. Uncertainty remains regarding the evolution of diurnal convection across the warm sector. Guidance generally suggests that surface-based storms will develop near the surface low and along the prefrontal trough/dryline across southern MN, which could evolve quickly into a cluster or linear mode, though the environment would still support embedded supercell potential with all severe hazards possible. If development in this area is able to remain semi-discrete, then a couple long-track tornadic supercells could occur. Farther south into IA, stronger heating/mixing is expected near the dryline, though large-scale ascent and low-level convergence may be somewhat weaker compared to areas farther north. While guidance varies regarding the potential for development across IA during the afternoon, any supercell that can initiate and be sustained could become long-tracked within the expanding and very favorable warm sector, posing a threat for strong to intense tornadoes and very large hail. As the surface low and related boundaries move eastward, organized convection may develop in place and/or spread into parts of WI, with a threat of all severe hazards and some strong-tornado potential. Farther west, a couple of supercells may develop in the region between the prefrontal trough/dryline and cold front, and pose a threat of large hail and locally damaging gusts as they move across northeast NE/southeast SD into parts of MN/IA. ...Parts of KS/MO into the Southern Plains... While large-scale ascent will be comparatively weaker from KS/MO into the southern Plains, isolated to widely scattered storm development will be possible within a weakly capped environment. Instability and deep-layer shear will both be moderate to strong by late afternoon into the evening, and a few supercells may develop near the dryline. Large to very large hail and locally damaging winds will likely be the initial primary hazard, but increasing low-level SRH by early evening will result in some tornado threat as well. Additional strong to locally severe storm development will be possible overnight near the advancing cold front, aided by a continued nocturnal strengthening of the low-level jet. ..Dean/Weinman.. 04/28/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Mon Apr 28 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS FOR SOUTHERN MINNESOTA...NORTHERN IOWA...AND WESTERN WISCONSIN... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest later today into tonight, with a regional severe weather outbreak possible. The most dangerous period is likely during the late afternoon and evening when strong tornado potential should be maximized. Scattered large to very large hail and damaging winds are likely as well. ...Synopsis... A positively tilted mid/upper-level shortwave trough, with several embedded vorticity maxima, will move east-northeast through the day across the Great Plains and Upper Midwest. The southwest portion of the large-scale trough and an embedded midlevel cyclone will remain in place near the Four Corners through most of the period. A strong midlevel jet (70+ kt at 500 mb) will move from the central Plains toward the upper Midwest/Great Lakes later today into this evening. The primary surface cyclone will move from the eastern Dakotas toward the upper Great Lakes, as a trailing cold front moves through parts of the Great Plains and eventually the Upper Midwest. By late afternoon, a dryline will extend from near the MN/IA border southwestward into the southern High Plains. ...Upper Midwest... A regional severe weather outbreak still appears possible across the Upper Midwest, with a threat of strong tornadoes, very large hail, and swaths of damaging winds. No major changes have been made to the Moderate and Enhanced Risk areas. Extensive elevated convection and a possible MCS will likely be ongoing at the start of the forecast period across parts of ND/MN, and may tend to redevelop through the day. This could slow the northward advance of the warm front to some extent, but 60s F dewpoints are expected reach at least central MN into northern WI by mid/late afternoon. South of the warm front and east of the dryline, the environment is expected to become increasingly volatile through the afternoon, with strong instability (MLCAPE near/above 3000 J/kg) and deep-layer shear, and a persistently intense low-level jet that will maintain very favorable low-level shear/SRH. This environment will be conditionally favorable for long-track supercells with strong/intense tornado potential. Uncertainty remains regarding the evolution of diurnal convection across the warm sector. Guidance generally suggests that surface-based storms will develop near the surface low and along the prefrontal trough/dryline across southern MN, which could evolve quickly into a cluster or linear mode, though the environment would still support embedded supercell potential with all severe hazards possible. If development in this area is able to remain semi-discrete, then a couple long-track tornadic supercells could occur. Farther south into IA, stronger heating/mixing is expected near the dryline, though large-scale ascent and low-level convergence may be somewhat weaker compared to areas farther north. While guidance varies regarding the potential for development across IA during the afternoon, any supercell that can initiate and be sustained could become long-tracked within the expanding and very favorable warm sector, posing a threat for strong to intense tornadoes and very large hail. As the surface low and related boundaries move eastward, organized convection may develop in place and/or spread into parts of WI, with a threat of all severe hazards and some strong-tornado potential. Farther west, a couple of supercells may develop in the region between the prefrontal trough/dryline and cold front, and pose a threat of large hail and locally damaging gusts as they move across northeast NE/southeast SD into parts of MN/IA. ...Parts of KS/MO into the Southern Plains... While large-scale ascent will be comparatively weaker from KS/MO into the southern Plains, isolated to widely scattered storm development will be possible within a weakly capped environment. Instability and deep-layer shear will both be moderate to strong by late afternoon into the evening, and a few supercells may develop near the dryline. Large to very large hail and locally damaging winds will likely be the initial primary hazard, but increasing low-level SRH by early evening will result in some tornado threat as well. Additional strong to locally severe storm development will be possible overnight near the advancing cold front, aided by a continued nocturnal strengthening of the low-level jet. ..Dean/Weinman.. 04/28/2025 Read more

WW 0179 Status Updates
STATUS REPORT ON WW 179 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 55 WSW RAP TO 35 NNE BHK. ..BROYLES..04/28/25 ATTN...WFO...BYZ...BIS...UNR... STATUS REPORT FOR WS 179 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NDC001-011-087-280640- ND . NORTH DAKOTA COUNTIES INCLUDED ARE ADAMS BOWMAN SLOPE SDC019-055-063-081-093-103-105-137-280640- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE BUTTE HAAKON HARDING LAWRENCE MEADE PENNINGTON PERKINS ZIEBACH THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 0179 Status Updates
STATUS REPORT ON WW 179 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 55 WSW RAP TO 35 NNE BHK. ..BROYLES..04/28/25 ATTN...WFO...BYZ...BIS...UNR... STATUS REPORT FOR WS 179 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NDC001-011-087-280640- ND . NORTH DAKOTA COUNTIES INCLUDED ARE ADAMS BOWMAN SLOPE SDC019-055-063-081-093-103-105-137-280640- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE BUTTE HAAKON HARDING LAWRENCE MEADE PENNINGTON PERKINS ZIEBACH THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

MD 0583 CONCERNING TORNADO WATCH 178... FOR CENTRAL PLAINS
Mesoscale Discussion 0583 NWS Storm Prediction Center Norman OK 1133 PM CDT Sun Apr 27 2025 Areas affected...Central Plains Concerning...Tornado Watch 178... Valid 280433Z - 280600Z The severe weather threat for Tornado Watch 178 continues. SUMMARY...Severe threat continues across northern Nebraska into southern South Dakota. WW178 will likely need to be extended beyond 05z. DISCUSSION...Intense LLJ currently extends across western KS into south-central SD. This feature will gradually translate east, focusing into eastern SD by 08z. Current radar trends suggest an MCS is maturing along the SD/NE border, and this complex should propagate downstream along the nose of the LLJ. Long-lived supercell -- tornadic at times -- is tracking across northeast Cherry County NE within a favorable warm advection zone, and very strong 0-3km SRH. Some tornado threat continues with this supercell, and any other discrete updrafts, though a gradual evolution into a larger complex is expected. Severe threat will continue well past 05z and ww178 will likely be extended to account for this scenario. ..Darrow.. 04/28/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FSD...ABR...LBF...UNR... LAT...LON 43110198 44229910 42989833 42010160 43110198 MOST PROBABLE PEAK TORNADO INTENSITY...100-130 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more

WW 179 SEVERE TSTM MT ND SD 272235Z - 280600Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 179 NWS Storm Prediction Center Norman OK 435 PM MDT Sun Apr 27 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Southeast Montana Southwest North Dakota Western South Dakota * Effective this Sunday afternoon from 435 PM until Midnight MDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Isolated damaging wind gusts to 70 mph possible A tornado or two possible SUMMARY...Severe storm development is expected across the region through the remainder of the afternoon into early/mid-evening, with large hail expected to the most probable risk, with damaging winds and possibly some/brief tornado risk as well. The severe thunderstorm watch area is approximately along and 80 statute miles east and west of a line from 45 miles west northwest of Baker MT to 35 miles east southeast of Rapid City SD. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU9). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 178... AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 24025. ...Guyer Read more

WW 0178 Status Updates
STATUS REPORT ON WW 178 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 E MHN TO 30 NNW MHN TO 15 SE PHP. ..BROYLES..04/28/25 ATTN...WFO...BOU...LBF...CYS...UNR... STATUS REPORT FOR WT 178 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NEC017-031-103-149-280640- NE . NEBRASKA COUNTIES INCLUDED ARE BROWN CHERRY KEYA PAHA ROCK SDC095-121-123-280640- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE MELLETTE TODD TRIPP THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 0178 Status Updates
STATUS REPORT ON WW 178 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 SE SNY TO 40 ENE AIA TO 40 SW PHP. ..SPC..04/28/25 ATTN...WFO...BOU...LBF...CYS...UNR... STATUS REPORT FOR WT 178 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NEC005-017-031-075-091-103-171-280540- NE . NEBRASKA COUNTIES INCLUDED ARE ARTHUR BROWN CHERRY GRANT HOOKER KEYA PAHA THOMAS SDC007-071-095-121-123-280540- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE BENNETT JACKSON MELLETTE TODD TRIPP THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 0178 Status Updates
STATUS REPORT ON WW 178 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 SE SNY TO 40 ENE AIA TO 40 SW PHP. ..SPC..04/28/25 ATTN...WFO...BOU...LBF...CYS...UNR... STATUS REPORT FOR WT 178 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NEC005-017-031-075-091-103-171-280540- NE . NEBRASKA COUNTIES INCLUDED ARE ARTHUR BROWN CHERRY GRANT HOOKER KEYA PAHA THOMAS SDC007-071-095-121-123-280540- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE BENNETT JACKSON MELLETTE TODD TRIPP THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

WW 178 TORNADO CO NE SD 272155Z - 280500Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 178 NWS Storm Prediction Center Norman OK 355 PM MDT Sun Apr 27 2025 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Far Northeast Colorado Western Nebraska Southwest South Dakota * Effective this Sunday afternoon and evening from 355 PM until 1100 PM MDT. * Primary threats include... A couple tornadoes possible Scattered large hail and isolated very large hail events to 3 inches in diameter possible Isolated damaging wind gusts to 70 mph possible SUMMARY...Severe storms including supercells are expected this evening, with very large hail possible as the main and initial hazard. Tornado potential is expected to increase toward/after sunset as additional low-level moistening occurs. Damaging winds are also possible. The tornado watch area is approximately along and 70 statute miles east and west of a line from 85 miles northeast of Chadron NE to 60 miles west southwest of North Platte NE. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU8). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. && AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 3 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 23030. ...Guyer Read more

WW 0179 Status Updates
STATUS REPORT ON WW 179 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 15 SW RAP TO 40 ENE 4BQ TO 25 NE BHK. ..SPC..04/28/25 ATTN...WFO...BYZ...BIS...UNR... STATUS REPORT FOR WS 179 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MTC011-025-280540- MT . MONTANA COUNTIES INCLUDED ARE CARTER FALLON NDC001-011-087-280540- ND . NORTH DAKOTA COUNTIES INCLUDED ARE ADAMS BOWMAN SLOPE SDC019-055-063-081-093-103-105-137-280540- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE BUTTE HAAKON HARDING LAWRENCE MEADE PENNINGTON PERKINS ZIEBACH Read more

MD 0582 CONCERNING SEVERE THUNDERSTORM WATCH 179... FOR NORTHERN HIGH PLAINS
Mesoscale Discussion 0582 NWS Storm Prediction Center Norman OK 0930 PM CDT Sun Apr 27 2025 Areas affected...Northern High Plains Concerning...Severe Thunderstorm Watch 179... Valid 280230Z - 280400Z The severe weather threat for Severe Thunderstorm Watch 179 continues. SUMMARY...Severe threat continues with thunderstorms this evening. DISCUSSION...Low-level convergence is gradually shifting east this evening as the primary surface cyclone is now into northeast CO. Even so, the main boundary currently arcs along the western fringe of ww179 from Carter County MT-western Pennington County SD. Several longer-lived storms with large hail are progressing across southeast MT toward northwest SD, while more liner activity appears to be evolving along the wind shift over the western Black Hills. Hail remains the primary concern with this activity, though the potential for gusty winds with line segments is of some concern. Severe threat continues. ..Darrow.. 04/28/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ABR...BIS...UNR...BYZ...GGW... LAT...LON 43840400 46580679 46590342 43830079 43840400 MOST PROBABLE PEAK TORNADO INTENSITY...85-115 MPH MOST PROBABLE PEAK WIND GUST...65-80 MPH MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN Read more

WW 0178 Status Updates
STATUS REPORT ON WW 178 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 NNW SNY TO 20 N AIA TO 10 N CDR. ..SPC..04/28/25 ATTN...WFO...BOU...LBF...CYS...UNR... STATUS REPORT FOR WT 178 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS COC115-280440- CO . COLORADO COUNTIES INCLUDED ARE SEDGWICK NEC005-029-031-045-049-069-075-085-091-101-111-113-117-123-135- 161-171-280440- NE . NEBRASKA COUNTIES INCLUDED ARE ARTHUR CHASE CHERRY DAWES DEUEL GARDEN GRANT HAYES HOOKER KEITH LINCOLN LOGAN MCPHERSON MORRILL PERKINS SHERIDAN THOMAS SDC007-071-095-102-121-280440- SD Read more

WW 0179 Status Updates
STATUS REPORT ON WW 179 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 SW RAP TO 40 NNE 4BQ TO 20 NNW BHK. ..SPC..04/28/25 ATTN...WFO...BYZ...BIS...UNR... STATUS REPORT FOR WS 179 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MTC011-025-280440- MT . MONTANA COUNTIES INCLUDED ARE CARTER FALLON NDC001-011-087-280440- ND . NORTH DAKOTA COUNTIES INCLUDED ARE ADAMS BOWMAN SLOPE SDC019-033-047-055-063-081-093-103-105-137-280440- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE BUTTE CUSTER FALL RIVER HAAKON HARDING LAWRENCE MEADE PENNINGTON PERKINS ZIEBACH Read more