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SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Sun Apr 27 2025 Valid 291200Z - 301200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN PARTS OF OH TO WESTERN PA/NY... ...SUMMARY... Scattered severe thunderstorms are likely across parts of the Lower Great Lakes on Tuesday afternoon/evening. Scattered severe thunderstorms are possible southwestward into the southern Great Plains. Isolated significant-severe potential, mainly from hail, is apparent across west Texas and separately in parts of the eastern Midwest to Lower Great Lakes. ...Synopsis... A consolidated shortwave trough should move east across the Great Lakes and southeast Canada. A southern-stream trough over the Southwest to northwest Mexico should drift east. Primary surface cyclone over northeast ON should quickly progress towards the Canadian Maritimes. An attendant cold front will push across the central to Lower Great Lakes Tuesday afternoon and evening. A weaker surface low should remain anchored over the TX Trans-Pecos. ...Eastern Midwest/Lower Great Lakes... The eastern extent of a pervasive EML will support potential for at least moderate buoyancy across a broadening warm-moist sector ahead of the aforementioned cold front. Rather strong mid-level westerlies should be present from the Great Lakes vicinity northward, trailing in magnitude but still moderate to strong across the OH Valley. While evolution of early-day convection from late D2 is uncertain, potential exists for pronounced boundary-layer heating amid robust low-level moistening to the northeast. With stronger mid-level height falls north of the international border, overall setup could favor discrete to semi-discrete supercells that eventually merge into clusters/short lines by evening. Confidence is sufficient in upgrading/expanding categorical risks along with adding a significant severe highlight, most likely for hail at this time. ...TX/OK... Multiple rounds of thunderstorms are expected through the period along a convectively modulated, quasi-stationary baroclinic zone. This renders enough uncertainty to mitigate a corridor of greater severe potential, but a mesoscale-driven Enhanced Risk may be needed in later outlooks. Adequate mid-level southwesterlies will persist through the period for supercells, with most guidance hinting at training convection along the west/southwest to east-northeast oriented portion of the zone near the Red River. More probable scenario for very large hail should exist to the southwest of that corridor, with a few dryline supercells favored in the late afternoon to early evening. ..Grams.. 04/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Sun Apr 27 2025 Valid 291200Z - 301200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN PARTS OF OH TO WESTERN PA/NY... ...SUMMARY... Scattered severe thunderstorms are likely across parts of the Lower Great Lakes on Tuesday afternoon/evening. Scattered severe thunderstorms are possible southwestward into the southern Great Plains. Isolated significant-severe potential, mainly from hail, is apparent across west Texas and separately in parts of the eastern Midwest to Lower Great Lakes. ...Synopsis... A consolidated shortwave trough should move east across the Great Lakes and southeast Canada. A southern-stream trough over the Southwest to northwest Mexico should drift east. Primary surface cyclone over northeast ON should quickly progress towards the Canadian Maritimes. An attendant cold front will push across the central to Lower Great Lakes Tuesday afternoon and evening. A weaker surface low should remain anchored over the TX Trans-Pecos. ...Eastern Midwest/Lower Great Lakes... The eastern extent of a pervasive EML will support potential for at least moderate buoyancy across a broadening warm-moist sector ahead of the aforementioned cold front. Rather strong mid-level westerlies should be present from the Great Lakes vicinity northward, trailing in magnitude but still moderate to strong across the OH Valley. While evolution of early-day convection from late D2 is uncertain, potential exists for pronounced boundary-layer heating amid robust low-level moistening to the northeast. With stronger mid-level height falls north of the international border, overall setup could favor discrete to semi-discrete supercells that eventually merge into clusters/short lines by evening. Confidence is sufficient in upgrading/expanding categorical risks along with adding a significant severe highlight, most likely for hail at this time. ...TX/OK... Multiple rounds of thunderstorms are expected through the period along a convectively modulated, quasi-stationary baroclinic zone. This renders enough uncertainty to mitigate a corridor of greater severe potential, but a mesoscale-driven Enhanced Risk may be needed in later outlooks. Adequate mid-level southwesterlies will persist through the period for supercells, with most guidance hinting at training convection along the west/southwest to east-northeast oriented portion of the zone near the Red River. More probable scenario for very large hail should exist to the southwest of that corridor, with a few dryline supercells favored in the late afternoon to early evening. ..Grams.. 04/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Sun Apr 27 2025 Valid 291200Z - 301200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN PARTS OF OH TO WESTERN PA/NY... ...SUMMARY... Scattered severe thunderstorms are likely across parts of the Lower Great Lakes on Tuesday afternoon/evening. Scattered severe thunderstorms are possible southwestward into the southern Great Plains. Isolated significant-severe potential, mainly from hail, is apparent across west Texas and separately in parts of the eastern Midwest to Lower Great Lakes. ...Synopsis... A consolidated shortwave trough should move east across the Great Lakes and southeast Canada. A southern-stream trough over the Southwest to northwest Mexico should drift east. Primary surface cyclone over northeast ON should quickly progress towards the Canadian Maritimes. An attendant cold front will push across the central to Lower Great Lakes Tuesday afternoon and evening. A weaker surface low should remain anchored over the TX Trans-Pecos. ...Eastern Midwest/Lower Great Lakes... The eastern extent of a pervasive EML will support potential for at least moderate buoyancy across a broadening warm-moist sector ahead of the aforementioned cold front. Rather strong mid-level westerlies should be present from the Great Lakes vicinity northward, trailing in magnitude but still moderate to strong across the OH Valley. While evolution of early-day convection from late D2 is uncertain, potential exists for pronounced boundary-layer heating amid robust low-level moistening to the northeast. With stronger mid-level height falls north of the international border, overall setup could favor discrete to semi-discrete supercells that eventually merge into clusters/short lines by evening. Confidence is sufficient in upgrading/expanding categorical risks along with adding a significant severe highlight, most likely for hail at this time. ...TX/OK... Multiple rounds of thunderstorms are expected through the period along a convectively modulated, quasi-stationary baroclinic zone. This renders enough uncertainty to mitigate a corridor of greater severe potential, but a mesoscale-driven Enhanced Risk may be needed in later outlooks. Adequate mid-level southwesterlies will persist through the period for supercells, with most guidance hinting at training convection along the west/southwest to east-northeast oriented portion of the zone near the Red River. More probable scenario for very large hail should exist to the southwest of that corridor, with a few dryline supercells favored in the late afternoon to early evening. ..Grams.. 04/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Sun Apr 27 2025 Valid 291200Z - 301200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN PARTS OF OH TO WESTERN PA/NY... ...SUMMARY... Scattered severe thunderstorms are likely across parts of the Lower Great Lakes on Tuesday afternoon/evening. Scattered severe thunderstorms are possible southwestward into the southern Great Plains. Isolated significant-severe potential, mainly from hail, is apparent across west Texas and separately in parts of the eastern Midwest to Lower Great Lakes. ...Synopsis... A consolidated shortwave trough should move east across the Great Lakes and southeast Canada. A southern-stream trough over the Southwest to northwest Mexico should drift east. Primary surface cyclone over northeast ON should quickly progress towards the Canadian Maritimes. An attendant cold front will push across the central to Lower Great Lakes Tuesday afternoon and evening. A weaker surface low should remain anchored over the TX Trans-Pecos. ...Eastern Midwest/Lower Great Lakes... The eastern extent of a pervasive EML will support potential for at least moderate buoyancy across a broadening warm-moist sector ahead of the aforementioned cold front. Rather strong mid-level westerlies should be present from the Great Lakes vicinity northward, trailing in magnitude but still moderate to strong across the OH Valley. While evolution of early-day convection from late D2 is uncertain, potential exists for pronounced boundary-layer heating amid robust low-level moistening to the northeast. With stronger mid-level height falls north of the international border, overall setup could favor discrete to semi-discrete supercells that eventually merge into clusters/short lines by evening. Confidence is sufficient in upgrading/expanding categorical risks along with adding a significant severe highlight, most likely for hail at this time. ...TX/OK... Multiple rounds of thunderstorms are expected through the period along a convectively modulated, quasi-stationary baroclinic zone. This renders enough uncertainty to mitigate a corridor of greater severe potential, but a mesoscale-driven Enhanced Risk may be needed in later outlooks. Adequate mid-level southwesterlies will persist through the period for supercells, with most guidance hinting at training convection along the west/southwest to east-northeast oriented portion of the zone near the Red River. More probable scenario for very large hail should exist to the southwest of that corridor, with a few dryline supercells favored in the late afternoon to early evening. ..Grams.. 04/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Sun Apr 27 2025 Valid 291200Z - 301200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN PARTS OF OH TO WESTERN PA/NY... ...SUMMARY... Scattered severe thunderstorms are likely across parts of the Lower Great Lakes on Tuesday afternoon/evening. Scattered severe thunderstorms are possible southwestward into the southern Great Plains. Isolated significant-severe potential, mainly from hail, is apparent across west Texas and separately in parts of the eastern Midwest to Lower Great Lakes. ...Synopsis... A consolidated shortwave trough should move east across the Great Lakes and southeast Canada. A southern-stream trough over the Southwest to northwest Mexico should drift east. Primary surface cyclone over northeast ON should quickly progress towards the Canadian Maritimes. An attendant cold front will push across the central to Lower Great Lakes Tuesday afternoon and evening. A weaker surface low should remain anchored over the TX Trans-Pecos. ...Eastern Midwest/Lower Great Lakes... The eastern extent of a pervasive EML will support potential for at least moderate buoyancy across a broadening warm-moist sector ahead of the aforementioned cold front. Rather strong mid-level westerlies should be present from the Great Lakes vicinity northward, trailing in magnitude but still moderate to strong across the OH Valley. While evolution of early-day convection from late D2 is uncertain, potential exists for pronounced boundary-layer heating amid robust low-level moistening to the northeast. With stronger mid-level height falls north of the international border, overall setup could favor discrete to semi-discrete supercells that eventually merge into clusters/short lines by evening. Confidence is sufficient in upgrading/expanding categorical risks along with adding a significant severe highlight, most likely for hail at this time. ...TX/OK... Multiple rounds of thunderstorms are expected through the period along a convectively modulated, quasi-stationary baroclinic zone. This renders enough uncertainty to mitigate a corridor of greater severe potential, but a mesoscale-driven Enhanced Risk may be needed in later outlooks. Adequate mid-level southwesterlies will persist through the period for supercells, with most guidance hinting at training convection along the west/southwest to east-northeast oriented portion of the zone near the Red River. More probable scenario for very large hail should exist to the southwest of that corridor, with a few dryline supercells favored in the late afternoon to early evening. ..Grams.. 04/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Sun Apr 27 2025 Valid 291200Z - 301200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN PARTS OF OH TO WESTERN PA/NY... ...SUMMARY... Scattered severe thunderstorms are likely across parts of the Lower Great Lakes on Tuesday afternoon/evening. Scattered severe thunderstorms are possible southwestward into the southern Great Plains. Isolated significant-severe potential, mainly from hail, is apparent across west Texas and separately in parts of the eastern Midwest to Lower Great Lakes. ...Synopsis... A consolidated shortwave trough should move east across the Great Lakes and southeast Canada. A southern-stream trough over the Southwest to northwest Mexico should drift east. Primary surface cyclone over northeast ON should quickly progress towards the Canadian Maritimes. An attendant cold front will push across the central to Lower Great Lakes Tuesday afternoon and evening. A weaker surface low should remain anchored over the TX Trans-Pecos. ...Eastern Midwest/Lower Great Lakes... The eastern extent of a pervasive EML will support potential for at least moderate buoyancy across a broadening warm-moist sector ahead of the aforementioned cold front. Rather strong mid-level westerlies should be present from the Great Lakes vicinity northward, trailing in magnitude but still moderate to strong across the OH Valley. While evolution of early-day convection from late D2 is uncertain, potential exists for pronounced boundary-layer heating amid robust low-level moistening to the northeast. With stronger mid-level height falls north of the international border, overall setup could favor discrete to semi-discrete supercells that eventually merge into clusters/short lines by evening. Confidence is sufficient in upgrading/expanding categorical risks along with adding a significant severe highlight, most likely for hail at this time. ...TX/OK... Multiple rounds of thunderstorms are expected through the period along a convectively modulated, quasi-stationary baroclinic zone. This renders enough uncertainty to mitigate a corridor of greater severe potential, but a mesoscale-driven Enhanced Risk may be needed in later outlooks. Adequate mid-level southwesterlies will persist through the period for supercells, with most guidance hinting at training convection along the west/southwest to east-northeast oriented portion of the zone near the Red River. More probable scenario for very large hail should exist to the southwest of that corridor, with a few dryline supercells favored in the late afternoon to early evening. ..Grams.. 04/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Sun Apr 27 2025 Valid 291200Z - 301200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN PARTS OF OH TO WESTERN PA/NY... ...SUMMARY... Scattered severe thunderstorms are likely across parts of the Lower Great Lakes on Tuesday afternoon/evening. Scattered severe thunderstorms are possible southwestward into the southern Great Plains. Isolated significant-severe potential, mainly from hail, is apparent across west Texas and separately in parts of the eastern Midwest to Lower Great Lakes. ...Synopsis... A consolidated shortwave trough should move east across the Great Lakes and southeast Canada. A southern-stream trough over the Southwest to northwest Mexico should drift east. Primary surface cyclone over northeast ON should quickly progress towards the Canadian Maritimes. An attendant cold front will push across the central to Lower Great Lakes Tuesday afternoon and evening. A weaker surface low should remain anchored over the TX Trans-Pecos. ...Eastern Midwest/Lower Great Lakes... The eastern extent of a pervasive EML will support potential for at least moderate buoyancy across a broadening warm-moist sector ahead of the aforementioned cold front. Rather strong mid-level westerlies should be present from the Great Lakes vicinity northward, trailing in magnitude but still moderate to strong across the OH Valley. While evolution of early-day convection from late D2 is uncertain, potential exists for pronounced boundary-layer heating amid robust low-level moistening to the northeast. With stronger mid-level height falls north of the international border, overall setup could favor discrete to semi-discrete supercells that eventually merge into clusters/short lines by evening. Confidence is sufficient in upgrading/expanding categorical risks along with adding a significant severe highlight, most likely for hail at this time. ...TX/OK... Multiple rounds of thunderstorms are expected through the period along a convectively modulated, quasi-stationary baroclinic zone. This renders enough uncertainty to mitigate a corridor of greater severe potential, but a mesoscale-driven Enhanced Risk may be needed in later outlooks. Adequate mid-level southwesterlies will persist through the period for supercells, with most guidance hinting at training convection along the west/southwest to east-northeast oriented portion of the zone near the Red River. More probable scenario for very large hail should exist to the southwest of that corridor, with a few dryline supercells favored in the late afternoon to early evening. ..Grams.. 04/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Sun Apr 27 2025 Valid 291200Z - 301200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN PARTS OF OH TO WESTERN PA/NY... ...SUMMARY... Scattered severe thunderstorms are likely across parts of the Lower Great Lakes on Tuesday afternoon/evening. Scattered severe thunderstorms are possible southwestward into the southern Great Plains. Isolated significant-severe potential, mainly from hail, is apparent across west Texas and separately in parts of the eastern Midwest to Lower Great Lakes. ...Synopsis... A consolidated shortwave trough should move east across the Great Lakes and southeast Canada. A southern-stream trough over the Southwest to northwest Mexico should drift east. Primary surface cyclone over northeast ON should quickly progress towards the Canadian Maritimes. An attendant cold front will push across the central to Lower Great Lakes Tuesday afternoon and evening. A weaker surface low should remain anchored over the TX Trans-Pecos. ...Eastern Midwest/Lower Great Lakes... The eastern extent of a pervasive EML will support potential for at least moderate buoyancy across a broadening warm-moist sector ahead of the aforementioned cold front. Rather strong mid-level westerlies should be present from the Great Lakes vicinity northward, trailing in magnitude but still moderate to strong across the OH Valley. While evolution of early-day convection from late D2 is uncertain, potential exists for pronounced boundary-layer heating amid robust low-level moistening to the northeast. With stronger mid-level height falls north of the international border, overall setup could favor discrete to semi-discrete supercells that eventually merge into clusters/short lines by evening. Confidence is sufficient in upgrading/expanding categorical risks along with adding a significant severe highlight, most likely for hail at this time. ...TX/OK... Multiple rounds of thunderstorms are expected through the period along a convectively modulated, quasi-stationary baroclinic zone. This renders enough uncertainty to mitigate a corridor of greater severe potential, but a mesoscale-driven Enhanced Risk may be needed in later outlooks. Adequate mid-level southwesterlies will persist through the period for supercells, with most guidance hinting at training convection along the west/southwest to east-northeast oriented portion of the zone near the Red River. More probable scenario for very large hail should exist to the southwest of that corridor, with a few dryline supercells favored in the late afternoon to early evening. ..Grams.. 04/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 PM CDT Sun Apr 27 2025 Valid 291200Z - 301200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS IN PARTS OF OH TO WESTERN PA/NY... ...SUMMARY... Scattered severe thunderstorms are likely across parts of the Lower Great Lakes on Tuesday afternoon/evening. Scattered severe thunderstorms are possible southwestward into the southern Great Plains. Isolated significant-severe potential, mainly from hail, is apparent across west Texas and separately in parts of the eastern Midwest to Lower Great Lakes. ...Synopsis... A consolidated shortwave trough should move east across the Great Lakes and southeast Canada. A southern-stream trough over the Southwest to northwest Mexico should drift east. Primary surface cyclone over northeast ON should quickly progress towards the Canadian Maritimes. An attendant cold front will push across the central to Lower Great Lakes Tuesday afternoon and evening. A weaker surface low should remain anchored over the TX Trans-Pecos. ...Eastern Midwest/Lower Great Lakes... The eastern extent of a pervasive EML will support potential for at least moderate buoyancy across a broadening warm-moist sector ahead of the aforementioned cold front. Rather strong mid-level westerlies should be present from the Great Lakes vicinity northward, trailing in magnitude but still moderate to strong across the OH Valley. While evolution of early-day convection from late D2 is uncertain, potential exists for pronounced boundary-layer heating amid robust low-level moistening to the northeast. With stronger mid-level height falls north of the international border, overall setup could favor discrete to semi-discrete supercells that eventually merge into clusters/short lines by evening. Confidence is sufficient in upgrading/expanding categorical risks along with adding a significant severe highlight, most likely for hail at this time. ...TX/OK... Multiple rounds of thunderstorms are expected through the period along a convectively modulated, quasi-stationary baroclinic zone. This renders enough uncertainty to mitigate a corridor of greater severe potential, but a mesoscale-driven Enhanced Risk may be needed in later outlooks. Adequate mid-level southwesterlies will persist through the period for supercells, with most guidance hinting at training convection along the west/southwest to east-northeast oriented portion of the zone near the Red River. More probable scenario for very large hail should exist to the southwest of that corridor, with a few dryline supercells favored in the late afternoon to early evening. ..Grams.. 04/27/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Sun Apr 27 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS IN SOUTHERN MN/NORTHERN IA/WESTERN WI... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest on Monday into Monday night, 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 positive-tilt, upper-level trough will consist of multiple embedded shortwave impulses, moving east-northeast from the central High Plains to the Upper Midwest. A belt of 70+ kt 500-mb southwesterlies will be present from the central Great Plains to the Upper MS Valley on Monday afternoon. Primary surface cyclone should deepen slightly during the day as it advances from eastern SD to the Upper Great Lakes. A dryline will extend from the Mid-MO Valley south-southwest into west TX. A cold front will overtake the dryline as it surges southeast Monday night. ...Upper Midwest... After coordination with affected WFOs, primary adjustments have occurred along the southern extent of the severe probabilities to account for a more conditional, but still potentially significant severe threat. An arc of elevated thunderstorms will be ongoing at 12Z Monday from ND across the Upper MS Valley. Isolated large hail will be possible with these morning storms as they move east-northeast. Additional elevated storms will redevelop towards midday/early afternoon to the northeast of the aforementioned surface low. This will slow the advancement of the surface warm front into central MN, but strengthen differential surface heating across the baroclinic zone, with greater warming nosing north from NE into southeast SD. Surface-based storm development should occur by mid-afternoon across a portion of the Mid-MO Valley into southwest/west-central MN along the dryline to surface low. Large hail should be the primary initial threat, but cells may congeal into linear clusters, especially near/across the warm front. A mix of hail/wind/embedded tornadoes is likely, with the latter increasing with southern/eastern extent during late afternoon owing to stronger low-level shear across southeast MN/northeast IA into western WI. Open warm-sector storm development ahead of the dryline is nebulous with low confidence on the degree of ascent ahead of the dryline given the synoptic setup. Conditionally, both the buoyancy/shear parameter space is volatile and supportive of potential for multiple long-track, tornadic supercells. Timing of mid-level height falls tends to favor the evening period after peak heating but CAM signals, outside of the 12Z FV3, are sparse. Greater large-scale ascent appears focused from far northeast IA into WI. This region remains the most favorable for discrete warm-sector development during the evening. Otherwise, upstream linear clusters from southern/eastern MN will likely spread across northern/central WI into parts of Upper MI with a mixed mode of all hazards persisting, before eventually weakening overnight. ...Eastern KS/northern MO to west TX... Overall forcing will be weaker farther south along the dryline, but subtle mid-level height falls across a mostly uncapped warm sector should result in isolated to scattered supercell development during the late afternoon to evening. This appears most likely across western north TX into southwest OK where greater boundary-layer heating and a nocturnally strengthening low-level jet are anticipated. ..Grams.. 04/27/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Sun Apr 27 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS IN SOUTHERN MN/NORTHERN IA/WESTERN WI... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest on Monday into Monday night, 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 positive-tilt, upper-level trough will consist of multiple embedded shortwave impulses, moving east-northeast from the central High Plains to the Upper Midwest. A belt of 70+ kt 500-mb southwesterlies will be present from the central Great Plains to the Upper MS Valley on Monday afternoon. Primary surface cyclone should deepen slightly during the day as it advances from eastern SD to the Upper Great Lakes. A dryline will extend from the Mid-MO Valley south-southwest into west TX. A cold front will overtake the dryline as it surges southeast Monday night. ...Upper Midwest... After coordination with affected WFOs, primary adjustments have occurred along the southern extent of the severe probabilities to account for a more conditional, but still potentially significant severe threat. An arc of elevated thunderstorms will be ongoing at 12Z Monday from ND across the Upper MS Valley. Isolated large hail will be possible with these morning storms as they move east-northeast. Additional elevated storms will redevelop towards midday/early afternoon to the northeast of the aforementioned surface low. This will slow the advancement of the surface warm front into central MN, but strengthen differential surface heating across the baroclinic zone, with greater warming nosing north from NE into southeast SD. Surface-based storm development should occur by mid-afternoon across a portion of the Mid-MO Valley into southwest/west-central MN along the dryline to surface low. Large hail should be the primary initial threat, but cells may congeal into linear clusters, especially near/across the warm front. A mix of hail/wind/embedded tornadoes is likely, with the latter increasing with southern/eastern extent during late afternoon owing to stronger low-level shear across southeast MN/northeast IA into western WI. Open warm-sector storm development ahead of the dryline is nebulous with low confidence on the degree of ascent ahead of the dryline given the synoptic setup. Conditionally, both the buoyancy/shear parameter space is volatile and supportive of potential for multiple long-track, tornadic supercells. Timing of mid-level height falls tends to favor the evening period after peak heating but CAM signals, outside of the 12Z FV3, are sparse. Greater large-scale ascent appears focused from far northeast IA into WI. This region remains the most favorable for discrete warm-sector development during the evening. Otherwise, upstream linear clusters from southern/eastern MN will likely spread across northern/central WI into parts of Upper MI with a mixed mode of all hazards persisting, before eventually weakening overnight. ...Eastern KS/northern MO to west TX... Overall forcing will be weaker farther south along the dryline, but subtle mid-level height falls across a mostly uncapped warm sector should result in isolated to scattered supercell development during the late afternoon to evening. This appears most likely across western north TX into southwest OK where greater boundary-layer heating and a nocturnally strengthening low-level jet are anticipated. ..Grams.. 04/27/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Sun Apr 27 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS IN SOUTHERN MN/NORTHERN IA/WESTERN WI... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest on Monday into Monday night, 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 positive-tilt, upper-level trough will consist of multiple embedded shortwave impulses, moving east-northeast from the central High Plains to the Upper Midwest. A belt of 70+ kt 500-mb southwesterlies will be present from the central Great Plains to the Upper MS Valley on Monday afternoon. Primary surface cyclone should deepen slightly during the day as it advances from eastern SD to the Upper Great Lakes. A dryline will extend from the Mid-MO Valley south-southwest into west TX. A cold front will overtake the dryline as it surges southeast Monday night. ...Upper Midwest... After coordination with affected WFOs, primary adjustments have occurred along the southern extent of the severe probabilities to account for a more conditional, but still potentially significant severe threat. An arc of elevated thunderstorms will be ongoing at 12Z Monday from ND across the Upper MS Valley. Isolated large hail will be possible with these morning storms as they move east-northeast. Additional elevated storms will redevelop towards midday/early afternoon to the northeast of the aforementioned surface low. This will slow the advancement of the surface warm front into central MN, but strengthen differential surface heating across the baroclinic zone, with greater warming nosing north from NE into southeast SD. Surface-based storm development should occur by mid-afternoon across a portion of the Mid-MO Valley into southwest/west-central MN along the dryline to surface low. Large hail should be the primary initial threat, but cells may congeal into linear clusters, especially near/across the warm front. A mix of hail/wind/embedded tornadoes is likely, with the latter increasing with southern/eastern extent during late afternoon owing to stronger low-level shear across southeast MN/northeast IA into western WI. Open warm-sector storm development ahead of the dryline is nebulous with low confidence on the degree of ascent ahead of the dryline given the synoptic setup. Conditionally, both the buoyancy/shear parameter space is volatile and supportive of potential for multiple long-track, tornadic supercells. Timing of mid-level height falls tends to favor the evening period after peak heating but CAM signals, outside of the 12Z FV3, are sparse. Greater large-scale ascent appears focused from far northeast IA into WI. This region remains the most favorable for discrete warm-sector development during the evening. Otherwise, upstream linear clusters from southern/eastern MN will likely spread across northern/central WI into parts of Upper MI with a mixed mode of all hazards persisting, before eventually weakening overnight. ...Eastern KS/northern MO to west TX... Overall forcing will be weaker farther south along the dryline, but subtle mid-level height falls across a mostly uncapped warm sector should result in isolated to scattered supercell development during the late afternoon to evening. This appears most likely across western north TX into southwest OK where greater boundary-layer heating and a nocturnally strengthening low-level jet are anticipated. ..Grams.. 04/27/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Sun Apr 27 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS IN SOUTHERN MN/NORTHERN IA/WESTERN WI... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest on Monday into Monday night, 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 positive-tilt, upper-level trough will consist of multiple embedded shortwave impulses, moving east-northeast from the central High Plains to the Upper Midwest. A belt of 70+ kt 500-mb southwesterlies will be present from the central Great Plains to the Upper MS Valley on Monday afternoon. Primary surface cyclone should deepen slightly during the day as it advances from eastern SD to the Upper Great Lakes. A dryline will extend from the Mid-MO Valley south-southwest into west TX. A cold front will overtake the dryline as it surges southeast Monday night. ...Upper Midwest... After coordination with affected WFOs, primary adjustments have occurred along the southern extent of the severe probabilities to account for a more conditional, but still potentially significant severe threat. An arc of elevated thunderstorms will be ongoing at 12Z Monday from ND across the Upper MS Valley. Isolated large hail will be possible with these morning storms as they move east-northeast. Additional elevated storms will redevelop towards midday/early afternoon to the northeast of the aforementioned surface low. This will slow the advancement of the surface warm front into central MN, but strengthen differential surface heating across the baroclinic zone, with greater warming nosing north from NE into southeast SD. Surface-based storm development should occur by mid-afternoon across a portion of the Mid-MO Valley into southwest/west-central MN along the dryline to surface low. Large hail should be the primary initial threat, but cells may congeal into linear clusters, especially near/across the warm front. A mix of hail/wind/embedded tornadoes is likely, with the latter increasing with southern/eastern extent during late afternoon owing to stronger low-level shear across southeast MN/northeast IA into western WI. Open warm-sector storm development ahead of the dryline is nebulous with low confidence on the degree of ascent ahead of the dryline given the synoptic setup. Conditionally, both the buoyancy/shear parameter space is volatile and supportive of potential for multiple long-track, tornadic supercells. Timing of mid-level height falls tends to favor the evening period after peak heating but CAM signals, outside of the 12Z FV3, are sparse. Greater large-scale ascent appears focused from far northeast IA into WI. This region remains the most favorable for discrete warm-sector development during the evening. Otherwise, upstream linear clusters from southern/eastern MN will likely spread across northern/central WI into parts of Upper MI with a mixed mode of all hazards persisting, before eventually weakening overnight. ...Eastern KS/northern MO to west TX... Overall forcing will be weaker farther south along the dryline, but subtle mid-level height falls across a mostly uncapped warm sector should result in isolated to scattered supercell development during the late afternoon to evening. This appears most likely across western north TX into southwest OK where greater boundary-layer heating and a nocturnally strengthening low-level jet are anticipated. ..Grams.. 04/27/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Sun Apr 27 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS IN SOUTHERN MN/NORTHERN IA/WESTERN WI... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest on Monday into Monday night, 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 positive-tilt, upper-level trough will consist of multiple embedded shortwave impulses, moving east-northeast from the central High Plains to the Upper Midwest. A belt of 70+ kt 500-mb southwesterlies will be present from the central Great Plains to the Upper MS Valley on Monday afternoon. Primary surface cyclone should deepen slightly during the day as it advances from eastern SD to the Upper Great Lakes. A dryline will extend from the Mid-MO Valley south-southwest into west TX. A cold front will overtake the dryline as it surges southeast Monday night. ...Upper Midwest... After coordination with affected WFOs, primary adjustments have occurred along the southern extent of the severe probabilities to account for a more conditional, but still potentially significant severe threat. An arc of elevated thunderstorms will be ongoing at 12Z Monday from ND across the Upper MS Valley. Isolated large hail will be possible with these morning storms as they move east-northeast. Additional elevated storms will redevelop towards midday/early afternoon to the northeast of the aforementioned surface low. This will slow the advancement of the surface warm front into central MN, but strengthen differential surface heating across the baroclinic zone, with greater warming nosing north from NE into southeast SD. Surface-based storm development should occur by mid-afternoon across a portion of the Mid-MO Valley into southwest/west-central MN along the dryline to surface low. Large hail should be the primary initial threat, but cells may congeal into linear clusters, especially near/across the warm front. A mix of hail/wind/embedded tornadoes is likely, with the latter increasing with southern/eastern extent during late afternoon owing to stronger low-level shear across southeast MN/northeast IA into western WI. Open warm-sector storm development ahead of the dryline is nebulous with low confidence on the degree of ascent ahead of the dryline given the synoptic setup. Conditionally, both the buoyancy/shear parameter space is volatile and supportive of potential for multiple long-track, tornadic supercells. Timing of mid-level height falls tends to favor the evening period after peak heating but CAM signals, outside of the 12Z FV3, are sparse. Greater large-scale ascent appears focused from far northeast IA into WI. This region remains the most favorable for discrete warm-sector development during the evening. Otherwise, upstream linear clusters from southern/eastern MN will likely spread across northern/central WI into parts of Upper MI with a mixed mode of all hazards persisting, before eventually weakening overnight. ...Eastern KS/northern MO to west TX... Overall forcing will be weaker farther south along the dryline, but subtle mid-level height falls across a mostly uncapped warm sector should result in isolated to scattered supercell development during the late afternoon to evening. This appears most likely across western north TX into southwest OK where greater boundary-layer heating and a nocturnally strengthening low-level jet are anticipated. ..Grams.. 04/27/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Sun Apr 27 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS IN SOUTHERN MN/NORTHERN IA/WESTERN WI... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest on Monday into Monday night, 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 positive-tilt, upper-level trough will consist of multiple embedded shortwave impulses, moving east-northeast from the central High Plains to the Upper Midwest. A belt of 70+ kt 500-mb southwesterlies will be present from the central Great Plains to the Upper MS Valley on Monday afternoon. Primary surface cyclone should deepen slightly during the day as it advances from eastern SD to the Upper Great Lakes. A dryline will extend from the Mid-MO Valley south-southwest into west TX. A cold front will overtake the dryline as it surges southeast Monday night. ...Upper Midwest... After coordination with affected WFOs, primary adjustments have occurred along the southern extent of the severe probabilities to account for a more conditional, but still potentially significant severe threat. An arc of elevated thunderstorms will be ongoing at 12Z Monday from ND across the Upper MS Valley. Isolated large hail will be possible with these morning storms as they move east-northeast. Additional elevated storms will redevelop towards midday/early afternoon to the northeast of the aforementioned surface low. This will slow the advancement of the surface warm front into central MN, but strengthen differential surface heating across the baroclinic zone, with greater warming nosing north from NE into southeast SD. Surface-based storm development should occur by mid-afternoon across a portion of the Mid-MO Valley into southwest/west-central MN along the dryline to surface low. Large hail should be the primary initial threat, but cells may congeal into linear clusters, especially near/across the warm front. A mix of hail/wind/embedded tornadoes is likely, with the latter increasing with southern/eastern extent during late afternoon owing to stronger low-level shear across southeast MN/northeast IA into western WI. Open warm-sector storm development ahead of the dryline is nebulous with low confidence on the degree of ascent ahead of the dryline given the synoptic setup. Conditionally, both the buoyancy/shear parameter space is volatile and supportive of potential for multiple long-track, tornadic supercells. Timing of mid-level height falls tends to favor the evening period after peak heating but CAM signals, outside of the 12Z FV3, are sparse. Greater large-scale ascent appears focused from far northeast IA into WI. This region remains the most favorable for discrete warm-sector development during the evening. Otherwise, upstream linear clusters from southern/eastern MN will likely spread across northern/central WI into parts of Upper MI with a mixed mode of all hazards persisting, before eventually weakening overnight. ...Eastern KS/northern MO to west TX... Overall forcing will be weaker farther south along the dryline, but subtle mid-level height falls across a mostly uncapped warm sector should result in isolated to scattered supercell development during the late afternoon to evening. This appears most likely across western north TX into southwest OK where greater boundary-layer heating and a nocturnally strengthening low-level jet are anticipated. ..Grams.. 04/27/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Sun Apr 27 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS IN SOUTHERN MN/NORTHERN IA/WESTERN WI... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest on Monday into Monday night, 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 positive-tilt, upper-level trough will consist of multiple embedded shortwave impulses, moving east-northeast from the central High Plains to the Upper Midwest. A belt of 70+ kt 500-mb southwesterlies will be present from the central Great Plains to the Upper MS Valley on Monday afternoon. Primary surface cyclone should deepen slightly during the day as it advances from eastern SD to the Upper Great Lakes. A dryline will extend from the Mid-MO Valley south-southwest into west TX. A cold front will overtake the dryline as it surges southeast Monday night. ...Upper Midwest... After coordination with affected WFOs, primary adjustments have occurred along the southern extent of the severe probabilities to account for a more conditional, but still potentially significant severe threat. An arc of elevated thunderstorms will be ongoing at 12Z Monday from ND across the Upper MS Valley. Isolated large hail will be possible with these morning storms as they move east-northeast. Additional elevated storms will redevelop towards midday/early afternoon to the northeast of the aforementioned surface low. This will slow the advancement of the surface warm front into central MN, but strengthen differential surface heating across the baroclinic zone, with greater warming nosing north from NE into southeast SD. Surface-based storm development should occur by mid-afternoon across a portion of the Mid-MO Valley into southwest/west-central MN along the dryline to surface low. Large hail should be the primary initial threat, but cells may congeal into linear clusters, especially near/across the warm front. A mix of hail/wind/embedded tornadoes is likely, with the latter increasing with southern/eastern extent during late afternoon owing to stronger low-level shear across southeast MN/northeast IA into western WI. Open warm-sector storm development ahead of the dryline is nebulous with low confidence on the degree of ascent ahead of the dryline given the synoptic setup. Conditionally, both the buoyancy/shear parameter space is volatile and supportive of potential for multiple long-track, tornadic supercells. Timing of mid-level height falls tends to favor the evening period after peak heating but CAM signals, outside of the 12Z FV3, are sparse. Greater large-scale ascent appears focused from far northeast IA into WI. This region remains the most favorable for discrete warm-sector development during the evening. Otherwise, upstream linear clusters from southern/eastern MN will likely spread across northern/central WI into parts of Upper MI with a mixed mode of all hazards persisting, before eventually weakening overnight. ...Eastern KS/northern MO to west TX... Overall forcing will be weaker farther south along the dryline, but subtle mid-level height falls across a mostly uncapped warm sector should result in isolated to scattered supercell development during the late afternoon to evening. This appears most likely across western north TX into southwest OK where greater boundary-layer heating and a nocturnally strengthening low-level jet are anticipated. ..Grams.. 04/27/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Sun Apr 27 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS IN SOUTHERN MN/NORTHERN IA/WESTERN WI... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest on Monday into Monday night, 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 positive-tilt, upper-level trough will consist of multiple embedded shortwave impulses, moving east-northeast from the central High Plains to the Upper Midwest. A belt of 70+ kt 500-mb southwesterlies will be present from the central Great Plains to the Upper MS Valley on Monday afternoon. Primary surface cyclone should deepen slightly during the day as it advances from eastern SD to the Upper Great Lakes. A dryline will extend from the Mid-MO Valley south-southwest into west TX. A cold front will overtake the dryline as it surges southeast Monday night. ...Upper Midwest... After coordination with affected WFOs, primary adjustments have occurred along the southern extent of the severe probabilities to account for a more conditional, but still potentially significant severe threat. An arc of elevated thunderstorms will be ongoing at 12Z Monday from ND across the Upper MS Valley. Isolated large hail will be possible with these morning storms as they move east-northeast. Additional elevated storms will redevelop towards midday/early afternoon to the northeast of the aforementioned surface low. This will slow the advancement of the surface warm front into central MN, but strengthen differential surface heating across the baroclinic zone, with greater warming nosing north from NE into southeast SD. Surface-based storm development should occur by mid-afternoon across a portion of the Mid-MO Valley into southwest/west-central MN along the dryline to surface low. Large hail should be the primary initial threat, but cells may congeal into linear clusters, especially near/across the warm front. A mix of hail/wind/embedded tornadoes is likely, with the latter increasing with southern/eastern extent during late afternoon owing to stronger low-level shear across southeast MN/northeast IA into western WI. Open warm-sector storm development ahead of the dryline is nebulous with low confidence on the degree of ascent ahead of the dryline given the synoptic setup. Conditionally, both the buoyancy/shear parameter space is volatile and supportive of potential for multiple long-track, tornadic supercells. Timing of mid-level height falls tends to favor the evening period after peak heating but CAM signals, outside of the 12Z FV3, are sparse. Greater large-scale ascent appears focused from far northeast IA into WI. This region remains the most favorable for discrete warm-sector development during the evening. Otherwise, upstream linear clusters from southern/eastern MN will likely spread across northern/central WI into parts of Upper MI with a mixed mode of all hazards persisting, before eventually weakening overnight. ...Eastern KS/northern MO to west TX... Overall forcing will be weaker farther south along the dryline, but subtle mid-level height falls across a mostly uncapped warm sector should result in isolated to scattered supercell development during the late afternoon to evening. This appears most likely across western north TX into southwest OK where greater boundary-layer heating and a nocturnally strengthening low-level jet are anticipated. ..Grams.. 04/27/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Sun Apr 27 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS IN SOUTHERN MN/NORTHERN IA/WESTERN WI... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest on Monday into Monday night, 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 positive-tilt, upper-level trough will consist of multiple embedded shortwave impulses, moving east-northeast from the central High Plains to the Upper Midwest. A belt of 70+ kt 500-mb southwesterlies will be present from the central Great Plains to the Upper MS Valley on Monday afternoon. Primary surface cyclone should deepen slightly during the day as it advances from eastern SD to the Upper Great Lakes. A dryline will extend from the Mid-MO Valley south-southwest into west TX. A cold front will overtake the dryline as it surges southeast Monday night. ...Upper Midwest... After coordination with affected WFOs, primary adjustments have occurred along the southern extent of the severe probabilities to account for a more conditional, but still potentially significant severe threat. An arc of elevated thunderstorms will be ongoing at 12Z Monday from ND across the Upper MS Valley. Isolated large hail will be possible with these morning storms as they move east-northeast. Additional elevated storms will redevelop towards midday/early afternoon to the northeast of the aforementioned surface low. This will slow the advancement of the surface warm front into central MN, but strengthen differential surface heating across the baroclinic zone, with greater warming nosing north from NE into southeast SD. Surface-based storm development should occur by mid-afternoon across a portion of the Mid-MO Valley into southwest/west-central MN along the dryline to surface low. Large hail should be the primary initial threat, but cells may congeal into linear clusters, especially near/across the warm front. A mix of hail/wind/embedded tornadoes is likely, with the latter increasing with southern/eastern extent during late afternoon owing to stronger low-level shear across southeast MN/northeast IA into western WI. Open warm-sector storm development ahead of the dryline is nebulous with low confidence on the degree of ascent ahead of the dryline given the synoptic setup. Conditionally, both the buoyancy/shear parameter space is volatile and supportive of potential for multiple long-track, tornadic supercells. Timing of mid-level height falls tends to favor the evening period after peak heating but CAM signals, outside of the 12Z FV3, are sparse. Greater large-scale ascent appears focused from far northeast IA into WI. This region remains the most favorable for discrete warm-sector development during the evening. Otherwise, upstream linear clusters from southern/eastern MN will likely spread across northern/central WI into parts of Upper MI with a mixed mode of all hazards persisting, before eventually weakening overnight. ...Eastern KS/northern MO to west TX... Overall forcing will be weaker farther south along the dryline, but subtle mid-level height falls across a mostly uncapped warm sector should result in isolated to scattered supercell development during the late afternoon to evening. This appears most likely across western north TX into southwest OK where greater boundary-layer heating and a nocturnally strengthening low-level jet are anticipated. ..Grams.. 04/27/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Sun Apr 27 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS IN SOUTHERN MN/NORTHERN IA/WESTERN WI... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest on Monday into Monday night, 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 positive-tilt, upper-level trough will consist of multiple embedded shortwave impulses, moving east-northeast from the central High Plains to the Upper Midwest. A belt of 70+ kt 500-mb southwesterlies will be present from the central Great Plains to the Upper MS Valley on Monday afternoon. Primary surface cyclone should deepen slightly during the day as it advances from eastern SD to the Upper Great Lakes. A dryline will extend from the Mid-MO Valley south-southwest into west TX. A cold front will overtake the dryline as it surges southeast Monday night. ...Upper Midwest... After coordination with affected WFOs, primary adjustments have occurred along the southern extent of the severe probabilities to account for a more conditional, but still potentially significant severe threat. An arc of elevated thunderstorms will be ongoing at 12Z Monday from ND across the Upper MS Valley. Isolated large hail will be possible with these morning storms as they move east-northeast. Additional elevated storms will redevelop towards midday/early afternoon to the northeast of the aforementioned surface low. This will slow the advancement of the surface warm front into central MN, but strengthen differential surface heating across the baroclinic zone, with greater warming nosing north from NE into southeast SD. Surface-based storm development should occur by mid-afternoon across a portion of the Mid-MO Valley into southwest/west-central MN along the dryline to surface low. Large hail should be the primary initial threat, but cells may congeal into linear clusters, especially near/across the warm front. A mix of hail/wind/embedded tornadoes is likely, with the latter increasing with southern/eastern extent during late afternoon owing to stronger low-level shear across southeast MN/northeast IA into western WI. Open warm-sector storm development ahead of the dryline is nebulous with low confidence on the degree of ascent ahead of the dryline given the synoptic setup. Conditionally, both the buoyancy/shear parameter space is volatile and supportive of potential for multiple long-track, tornadic supercells. Timing of mid-level height falls tends to favor the evening period after peak heating but CAM signals, outside of the 12Z FV3, are sparse. Greater large-scale ascent appears focused from far northeast IA into WI. This region remains the most favorable for discrete warm-sector development during the evening. Otherwise, upstream linear clusters from southern/eastern MN will likely spread across northern/central WI into parts of Upper MI with a mixed mode of all hazards persisting, before eventually weakening overnight. ...Eastern KS/northern MO to west TX... Overall forcing will be weaker farther south along the dryline, but subtle mid-level height falls across a mostly uncapped warm sector should result in isolated to scattered supercell development during the late afternoon to evening. This appears most likely across western north TX into southwest OK where greater boundary-layer heating and a nocturnally strengthening low-level jet are anticipated. ..Grams.. 04/27/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1233 PM CDT Sun Apr 27 2025 Valid 281200Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS IN SOUTHERN MN/NORTHERN IA/WESTERN WI... ...SUMMARY... Multiple corridors of severe thunderstorms are expected across the Upper Midwest on Monday into Monday night, 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 positive-tilt, upper-level trough will consist of multiple embedded shortwave impulses, moving east-northeast from the central High Plains to the Upper Midwest. A belt of 70+ kt 500-mb southwesterlies will be present from the central Great Plains to the Upper MS Valley on Monday afternoon. Primary surface cyclone should deepen slightly during the day as it advances from eastern SD to the Upper Great Lakes. A dryline will extend from the Mid-MO Valley south-southwest into west TX. A cold front will overtake the dryline as it surges southeast Monday night. ...Upper Midwest... After coordination with affected WFOs, primary adjustments have occurred along the southern extent of the severe probabilities to account for a more conditional, but still potentially significant severe threat. An arc of elevated thunderstorms will be ongoing at 12Z Monday from ND across the Upper MS Valley. Isolated large hail will be possible with these morning storms as they move east-northeast. Additional elevated storms will redevelop towards midday/early afternoon to the northeast of the aforementioned surface low. This will slow the advancement of the surface warm front into central MN, but strengthen differential surface heating across the baroclinic zone, with greater warming nosing north from NE into southeast SD. Surface-based storm development should occur by mid-afternoon across a portion of the Mid-MO Valley into southwest/west-central MN along the dryline to surface low. Large hail should be the primary initial threat, but cells may congeal into linear clusters, especially near/across the warm front. A mix of hail/wind/embedded tornadoes is likely, with the latter increasing with southern/eastern extent during late afternoon owing to stronger low-level shear across southeast MN/northeast IA into western WI. Open warm-sector storm development ahead of the dryline is nebulous with low confidence on the degree of ascent ahead of the dryline given the synoptic setup. Conditionally, both the buoyancy/shear parameter space is volatile and supportive of potential for multiple long-track, tornadic supercells. Timing of mid-level height falls tends to favor the evening period after peak heating but CAM signals, outside of the 12Z FV3, are sparse. Greater large-scale ascent appears focused from far northeast IA into WI. This region remains the most favorable for discrete warm-sector development during the evening. Otherwise, upstream linear clusters from southern/eastern MN will likely spread across northern/central WI into parts of Upper MI with a mixed mode of all hazards persisting, before eventually weakening overnight. ...Eastern KS/northern MO to west TX... Overall forcing will be weaker farther south along the dryline, but subtle mid-level height falls across a mostly uncapped warm sector should result in isolated to scattered supercell development during the late afternoon to evening. This appears most likely across western north TX into southwest OK where greater boundary-layer heating and a nocturnally strengthening low-level jet are anticipated. ..Grams.. 04/27/2025 Read more