Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jul 27 2025 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN/CENTRAL MINNESOTA AND FAR EASTERN SOUTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC STATES... ...SUMMARY... Severe thunderstorms are expected this afternoon and evening across parts of the Upper Midwest to western Great Lakes. Other severe storms are also possible in parts of the northern Plains, central Appalachians, and Mid-Atlantic. ...20Z Update... Both the Slight and Enhanced risks were expanded slightly west-southwestward in eastern SD with this update. Here, the latest guidance has come into relatively good agreement, depicting convective development ahead of a gradually evolving surface low into this evening. Very steep deep-layer lapse rates/extreme surface-based buoyancy and 40-50 kt of effective shear will promote supercells/organized clusters capable of producing large hail and severe wind gusts. Farther east, the Marginal risk was expanded southward across southeastern NC into northern SC. Strong heating/destabilization will promote damaging wind gusts with any small thunderstorm clusters that evolve. ..Weinman.. 07/27/2025 .PREV DISCUSSION... /ISSUED 1200 PM CDT Sun Jul 27 2025/ ...Upper Midwest/western Great Lakes including MN/eastern SD... A convectively enhanced mid-level shortwave trough over northern/eastern North Dakota will continue generally eastward toward northern Minnesota, with a modest flattening of the downstream upper-level ridge into tonight. A modest deepening of the surface low will occur across eastern South Dakota toward the southwest Minnesota border vicinity, with intense thunderstorm development later today generally expected to focus along the southeastward-advancing front, although differential heating and a convectively aided cluster/possible MCV across northeast South Dakota at midday may also be factors. Given the strong buoyancy near/south of the front, and very steep lapse rates/elevated mixed layer impinging from the west-southwest, modestly strong wind profiles will be sufficient for intense supercell development with initial storms, including large hail potential (higher magnitudes possible especially eastern South Dakotas and southwest Minnesota) and some tornado risk. Multiple southeastward-moving clusters should evolve this evening with an increasing likelihood of damaging wind across southern Minnesota into western/northern Wisconsin. Portions of the region have been upgraded to an Enhanced Risk. ...Mid-Atlantic/Central Appalachians... Scattered afternoon thunderstorms will continue to increase regionally. Similar to previous days, mid-level lapse rates will be weak and considerable mid-level moisture will keep the overall potential somewhat limited/isolated. However, the strongest cells will be capable of occasional gusty/damaging winds, with a somewhat higher probability of wind damage seemingly existing across eastern Virginia where buoyancy will be greater. ...Montana... Strong heating will occur this afternoon across much of central/eastern Montana, where deep boundary-layer mixing will lead to inverted-v profiles. Scattered thunderstorms are forecast to develop along a corridor from southwest into central Montana by late afternoon. These high-based storms may pose a risk of a few severe-caliber wind gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jul 27 2025 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN/CENTRAL MINNESOTA AND FAR EASTERN SOUTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC STATES... ...SUMMARY... Severe thunderstorms are expected this afternoon and evening across parts of the Upper Midwest to western Great Lakes. Other severe storms are also possible in parts of the northern Plains, central Appalachians, and Mid-Atlantic. ...20Z Update... Both the Slight and Enhanced risks were expanded slightly west-southwestward in eastern SD with this update. Here, the latest guidance has come into relatively good agreement, depicting convective development ahead of a gradually evolving surface low into this evening. Very steep deep-layer lapse rates/extreme surface-based buoyancy and 40-50 kt of effective shear will promote supercells/organized clusters capable of producing large hail and severe wind gusts. Farther east, the Marginal risk was expanded southward across southeastern NC into northern SC. Strong heating/destabilization will promote damaging wind gusts with any small thunderstorm clusters that evolve. ..Weinman.. 07/27/2025 .PREV DISCUSSION... /ISSUED 1200 PM CDT Sun Jul 27 2025/ ...Upper Midwest/western Great Lakes including MN/eastern SD... A convectively enhanced mid-level shortwave trough over northern/eastern North Dakota will continue generally eastward toward northern Minnesota, with a modest flattening of the downstream upper-level ridge into tonight. A modest deepening of the surface low will occur across eastern South Dakota toward the southwest Minnesota border vicinity, with intense thunderstorm development later today generally expected to focus along the southeastward-advancing front, although differential heating and a convectively aided cluster/possible MCV across northeast South Dakota at midday may also be factors. Given the strong buoyancy near/south of the front, and very steep lapse rates/elevated mixed layer impinging from the west-southwest, modestly strong wind profiles will be sufficient for intense supercell development with initial storms, including large hail potential (higher magnitudes possible especially eastern South Dakotas and southwest Minnesota) and some tornado risk. Multiple southeastward-moving clusters should evolve this evening with an increasing likelihood of damaging wind across southern Minnesota into western/northern Wisconsin. Portions of the region have been upgraded to an Enhanced Risk. ...Mid-Atlantic/Central Appalachians... Scattered afternoon thunderstorms will continue to increase regionally. Similar to previous days, mid-level lapse rates will be weak and considerable mid-level moisture will keep the overall potential somewhat limited/isolated. However, the strongest cells will be capable of occasional gusty/damaging winds, with a somewhat higher probability of wind damage seemingly existing across eastern Virginia where buoyancy will be greater. ...Montana... Strong heating will occur this afternoon across much of central/eastern Montana, where deep boundary-layer mixing will lead to inverted-v profiles. Scattered thunderstorms are forecast to develop along a corridor from southwest into central Montana by late afternoon. These high-based storms may pose a risk of a few severe-caliber wind gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jul 27 2025 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN/CENTRAL MINNESOTA AND FAR EASTERN SOUTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC STATES... ...SUMMARY... Severe thunderstorms are expected this afternoon and evening across parts of the Upper Midwest to western Great Lakes. Other severe storms are also possible in parts of the northern Plains, central Appalachians, and Mid-Atlantic. ...20Z Update... Both the Slight and Enhanced risks were expanded slightly west-southwestward in eastern SD with this update. Here, the latest guidance has come into relatively good agreement, depicting convective development ahead of a gradually evolving surface low into this evening. Very steep deep-layer lapse rates/extreme surface-based buoyancy and 40-50 kt of effective shear will promote supercells/organized clusters capable of producing large hail and severe wind gusts. Farther east, the Marginal risk was expanded southward across southeastern NC into northern SC. Strong heating/destabilization will promote damaging wind gusts with any small thunderstorm clusters that evolve. ..Weinman.. 07/27/2025 .PREV DISCUSSION... /ISSUED 1200 PM CDT Sun Jul 27 2025/ ...Upper Midwest/western Great Lakes including MN/eastern SD... A convectively enhanced mid-level shortwave trough over northern/eastern North Dakota will continue generally eastward toward northern Minnesota, with a modest flattening of the downstream upper-level ridge into tonight. A modest deepening of the surface low will occur across eastern South Dakota toward the southwest Minnesota border vicinity, with intense thunderstorm development later today generally expected to focus along the southeastward-advancing front, although differential heating and a convectively aided cluster/possible MCV across northeast South Dakota at midday may also be factors. Given the strong buoyancy near/south of the front, and very steep lapse rates/elevated mixed layer impinging from the west-southwest, modestly strong wind profiles will be sufficient for intense supercell development with initial storms, including large hail potential (higher magnitudes possible especially eastern South Dakotas and southwest Minnesota) and some tornado risk. Multiple southeastward-moving clusters should evolve this evening with an increasing likelihood of damaging wind across southern Minnesota into western/northern Wisconsin. Portions of the region have been upgraded to an Enhanced Risk. ...Mid-Atlantic/Central Appalachians... Scattered afternoon thunderstorms will continue to increase regionally. Similar to previous days, mid-level lapse rates will be weak and considerable mid-level moisture will keep the overall potential somewhat limited/isolated. However, the strongest cells will be capable of occasional gusty/damaging winds, with a somewhat higher probability of wind damage seemingly existing across eastern Virginia where buoyancy will be greater. ...Montana... Strong heating will occur this afternoon across much of central/eastern Montana, where deep boundary-layer mixing will lead to inverted-v profiles. Scattered thunderstorms are forecast to develop along a corridor from southwest into central Montana by late afternoon. These high-based storms may pose a risk of a few severe-caliber wind gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jul 27 2025 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN/CENTRAL MINNESOTA AND FAR EASTERN SOUTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC STATES... ...SUMMARY... Severe thunderstorms are expected this afternoon and evening across parts of the Upper Midwest to western Great Lakes. Other severe storms are also possible in parts of the northern Plains, central Appalachians, and Mid-Atlantic. ...20Z Update... Both the Slight and Enhanced risks were expanded slightly west-southwestward in eastern SD with this update. Here, the latest guidance has come into relatively good agreement, depicting convective development ahead of a gradually evolving surface low into this evening. Very steep deep-layer lapse rates/extreme surface-based buoyancy and 40-50 kt of effective shear will promote supercells/organized clusters capable of producing large hail and severe wind gusts. Farther east, the Marginal risk was expanded southward across southeastern NC into northern SC. Strong heating/destabilization will promote damaging wind gusts with any small thunderstorm clusters that evolve. ..Weinman.. 07/27/2025 .PREV DISCUSSION... /ISSUED 1200 PM CDT Sun Jul 27 2025/ ...Upper Midwest/western Great Lakes including MN/eastern SD... A convectively enhanced mid-level shortwave trough over northern/eastern North Dakota will continue generally eastward toward northern Minnesota, with a modest flattening of the downstream upper-level ridge into tonight. A modest deepening of the surface low will occur across eastern South Dakota toward the southwest Minnesota border vicinity, with intense thunderstorm development later today generally expected to focus along the southeastward-advancing front, although differential heating and a convectively aided cluster/possible MCV across northeast South Dakota at midday may also be factors. Given the strong buoyancy near/south of the front, and very steep lapse rates/elevated mixed layer impinging from the west-southwest, modestly strong wind profiles will be sufficient for intense supercell development with initial storms, including large hail potential (higher magnitudes possible especially eastern South Dakotas and southwest Minnesota) and some tornado risk. Multiple southeastward-moving clusters should evolve this evening with an increasing likelihood of damaging wind across southern Minnesota into western/northern Wisconsin. Portions of the region have been upgraded to an Enhanced Risk. ...Mid-Atlantic/Central Appalachians... Scattered afternoon thunderstorms will continue to increase regionally. Similar to previous days, mid-level lapse rates will be weak and considerable mid-level moisture will keep the overall potential somewhat limited/isolated. However, the strongest cells will be capable of occasional gusty/damaging winds, with a somewhat higher probability of wind damage seemingly existing across eastern Virginia where buoyancy will be greater. ...Montana... Strong heating will occur this afternoon across much of central/eastern Montana, where deep boundary-layer mixing will lead to inverted-v profiles. Scattered thunderstorms are forecast to develop along a corridor from southwest into central Montana by late afternoon. These high-based storms may pose a risk of a few severe-caliber wind gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jul 27 2025 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN/CENTRAL MINNESOTA AND FAR EASTERN SOUTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC STATES... ...SUMMARY... Severe thunderstorms are expected this afternoon and evening across parts of the Upper Midwest to western Great Lakes. Other severe storms are also possible in parts of the northern Plains, central Appalachians, and Mid-Atlantic. ...20Z Update... Both the Slight and Enhanced risks were expanded slightly west-southwestward in eastern SD with this update. Here, the latest guidance has come into relatively good agreement, depicting convective development ahead of a gradually evolving surface low into this evening. Very steep deep-layer lapse rates/extreme surface-based buoyancy and 40-50 kt of effective shear will promote supercells/organized clusters capable of producing large hail and severe wind gusts. Farther east, the Marginal risk was expanded southward across southeastern NC into northern SC. Strong heating/destabilization will promote damaging wind gusts with any small thunderstorm clusters that evolve. ..Weinman.. 07/27/2025 .PREV DISCUSSION... /ISSUED 1200 PM CDT Sun Jul 27 2025/ ...Upper Midwest/western Great Lakes including MN/eastern SD... A convectively enhanced mid-level shortwave trough over northern/eastern North Dakota will continue generally eastward toward northern Minnesota, with a modest flattening of the downstream upper-level ridge into tonight. A modest deepening of the surface low will occur across eastern South Dakota toward the southwest Minnesota border vicinity, with intense thunderstorm development later today generally expected to focus along the southeastward-advancing front, although differential heating and a convectively aided cluster/possible MCV across northeast South Dakota at midday may also be factors. Given the strong buoyancy near/south of the front, and very steep lapse rates/elevated mixed layer impinging from the west-southwest, modestly strong wind profiles will be sufficient for intense supercell development with initial storms, including large hail potential (higher magnitudes possible especially eastern South Dakotas and southwest Minnesota) and some tornado risk. Multiple southeastward-moving clusters should evolve this evening with an increasing likelihood of damaging wind across southern Minnesota into western/northern Wisconsin. Portions of the region have been upgraded to an Enhanced Risk. ...Mid-Atlantic/Central Appalachians... Scattered afternoon thunderstorms will continue to increase regionally. Similar to previous days, mid-level lapse rates will be weak and considerable mid-level moisture will keep the overall potential somewhat limited/isolated. However, the strongest cells will be capable of occasional gusty/damaging winds, with a somewhat higher probability of wind damage seemingly existing across eastern Virginia where buoyancy will be greater. ...Montana... Strong heating will occur this afternoon across much of central/eastern Montana, where deep boundary-layer mixing will lead to inverted-v profiles. Scattered thunderstorms are forecast to develop along a corridor from southwest into central Montana by late afternoon. These high-based storms may pose a risk of a few severe-caliber wind gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jul 27 2025 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN/CENTRAL MINNESOTA AND FAR EASTERN SOUTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC STATES... ...SUMMARY... Severe thunderstorms are expected this afternoon and evening across parts of the Upper Midwest to western Great Lakes. Other severe storms are also possible in parts of the northern Plains, central Appalachians, and Mid-Atlantic. ...20Z Update... Both the Slight and Enhanced risks were expanded slightly west-southwestward in eastern SD with this update. Here, the latest guidance has come into relatively good agreement, depicting convective development ahead of a gradually evolving surface low into this evening. Very steep deep-layer lapse rates/extreme surface-based buoyancy and 40-50 kt of effective shear will promote supercells/organized clusters capable of producing large hail and severe wind gusts. Farther east, the Marginal risk was expanded southward across southeastern NC into northern SC. Strong heating/destabilization will promote damaging wind gusts with any small thunderstorm clusters that evolve. ..Weinman.. 07/27/2025 .PREV DISCUSSION... /ISSUED 1200 PM CDT Sun Jul 27 2025/ ...Upper Midwest/western Great Lakes including MN/eastern SD... A convectively enhanced mid-level shortwave trough over northern/eastern North Dakota will continue generally eastward toward northern Minnesota, with a modest flattening of the downstream upper-level ridge into tonight. A modest deepening of the surface low will occur across eastern South Dakota toward the southwest Minnesota border vicinity, with intense thunderstorm development later today generally expected to focus along the southeastward-advancing front, although differential heating and a convectively aided cluster/possible MCV across northeast South Dakota at midday may also be factors. Given the strong buoyancy near/south of the front, and very steep lapse rates/elevated mixed layer impinging from the west-southwest, modestly strong wind profiles will be sufficient for intense supercell development with initial storms, including large hail potential (higher magnitudes possible especially eastern South Dakotas and southwest Minnesota) and some tornado risk. Multiple southeastward-moving clusters should evolve this evening with an increasing likelihood of damaging wind across southern Minnesota into western/northern Wisconsin. Portions of the region have been upgraded to an Enhanced Risk. ...Mid-Atlantic/Central Appalachians... Scattered afternoon thunderstorms will continue to increase regionally. Similar to previous days, mid-level lapse rates will be weak and considerable mid-level moisture will keep the overall potential somewhat limited/isolated. However, the strongest cells will be capable of occasional gusty/damaging winds, with a somewhat higher probability of wind damage seemingly existing across eastern Virginia where buoyancy will be greater. ...Montana... Strong heating will occur this afternoon across much of central/eastern Montana, where deep boundary-layer mixing will lead to inverted-v profiles. Scattered thunderstorms are forecast to develop along a corridor from southwest into central Montana by late afternoon. These high-based storms may pose a risk of a few severe-caliber wind gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jul 27 2025 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN/CENTRAL MINNESOTA AND FAR EASTERN SOUTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC STATES... ...SUMMARY... Severe thunderstorms are expected this afternoon and evening across parts of the Upper Midwest to western Great Lakes. Other severe storms are also possible in parts of the northern Plains, central Appalachians, and Mid-Atlantic. ...20Z Update... Both the Slight and Enhanced risks were expanded slightly west-southwestward in eastern SD with this update. Here, the latest guidance has come into relatively good agreement, depicting convective development ahead of a gradually evolving surface low into this evening. Very steep deep-layer lapse rates/extreme surface-based buoyancy and 40-50 kt of effective shear will promote supercells/organized clusters capable of producing large hail and severe wind gusts. Farther east, the Marginal risk was expanded southward across southeastern NC into northern SC. Strong heating/destabilization will promote damaging wind gusts with any small thunderstorm clusters that evolve. ..Weinman.. 07/27/2025 .PREV DISCUSSION... /ISSUED 1200 PM CDT Sun Jul 27 2025/ ...Upper Midwest/western Great Lakes including MN/eastern SD... A convectively enhanced mid-level shortwave trough over northern/eastern North Dakota will continue generally eastward toward northern Minnesota, with a modest flattening of the downstream upper-level ridge into tonight. A modest deepening of the surface low will occur across eastern South Dakota toward the southwest Minnesota border vicinity, with intense thunderstorm development later today generally expected to focus along the southeastward-advancing front, although differential heating and a convectively aided cluster/possible MCV across northeast South Dakota at midday may also be factors. Given the strong buoyancy near/south of the front, and very steep lapse rates/elevated mixed layer impinging from the west-southwest, modestly strong wind profiles will be sufficient for intense supercell development with initial storms, including large hail potential (higher magnitudes possible especially eastern South Dakotas and southwest Minnesota) and some tornado risk. Multiple southeastward-moving clusters should evolve this evening with an increasing likelihood of damaging wind across southern Minnesota into western/northern Wisconsin. Portions of the region have been upgraded to an Enhanced Risk. ...Mid-Atlantic/Central Appalachians... Scattered afternoon thunderstorms will continue to increase regionally. Similar to previous days, mid-level lapse rates will be weak and considerable mid-level moisture will keep the overall potential somewhat limited/isolated. However, the strongest cells will be capable of occasional gusty/damaging winds, with a somewhat higher probability of wind damage seemingly existing across eastern Virginia where buoyancy will be greater. ...Montana... Strong heating will occur this afternoon across much of central/eastern Montana, where deep boundary-layer mixing will lead to inverted-v profiles. Scattered thunderstorms are forecast to develop along a corridor from southwest into central Montana by late afternoon. These high-based storms may pose a risk of a few severe-caliber wind gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jul 27 2025 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN/CENTRAL MINNESOTA AND FAR EASTERN SOUTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC STATES... ...SUMMARY... Severe thunderstorms are expected this afternoon and evening across parts of the Upper Midwest to western Great Lakes. Other severe storms are also possible in parts of the northern Plains, central Appalachians, and Mid-Atlantic. ...20Z Update... Both the Slight and Enhanced risks were expanded slightly west-southwestward in eastern SD with this update. Here, the latest guidance has come into relatively good agreement, depicting convective development ahead of a gradually evolving surface low into this evening. Very steep deep-layer lapse rates/extreme surface-based buoyancy and 40-50 kt of effective shear will promote supercells/organized clusters capable of producing large hail and severe wind gusts. Farther east, the Marginal risk was expanded southward across southeastern NC into northern SC. Strong heating/destabilization will promote damaging wind gusts with any small thunderstorm clusters that evolve. ..Weinman.. 07/27/2025 .PREV DISCUSSION... /ISSUED 1200 PM CDT Sun Jul 27 2025/ ...Upper Midwest/western Great Lakes including MN/eastern SD... A convectively enhanced mid-level shortwave trough over northern/eastern North Dakota will continue generally eastward toward northern Minnesota, with a modest flattening of the downstream upper-level ridge into tonight. A modest deepening of the surface low will occur across eastern South Dakota toward the southwest Minnesota border vicinity, with intense thunderstorm development later today generally expected to focus along the southeastward-advancing front, although differential heating and a convectively aided cluster/possible MCV across northeast South Dakota at midday may also be factors. Given the strong buoyancy near/south of the front, and very steep lapse rates/elevated mixed layer impinging from the west-southwest, modestly strong wind profiles will be sufficient for intense supercell development with initial storms, including large hail potential (higher magnitudes possible especially eastern South Dakotas and southwest Minnesota) and some tornado risk. Multiple southeastward-moving clusters should evolve this evening with an increasing likelihood of damaging wind across southern Minnesota into western/northern Wisconsin. Portions of the region have been upgraded to an Enhanced Risk. ...Mid-Atlantic/Central Appalachians... Scattered afternoon thunderstorms will continue to increase regionally. Similar to previous days, mid-level lapse rates will be weak and considerable mid-level moisture will keep the overall potential somewhat limited/isolated. However, the strongest cells will be capable of occasional gusty/damaging winds, with a somewhat higher probability of wind damage seemingly existing across eastern Virginia where buoyancy will be greater. ...Montana... Strong heating will occur this afternoon across much of central/eastern Montana, where deep boundary-layer mixing will lead to inverted-v profiles. Scattered thunderstorms are forecast to develop along a corridor from southwest into central Montana by late afternoon. These high-based storms may pose a risk of a few severe-caliber wind gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jul 27 2025 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN/CENTRAL MINNESOTA AND FAR EASTERN SOUTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC STATES... ...SUMMARY... Severe thunderstorms are expected this afternoon and evening across parts of the Upper Midwest to western Great Lakes. Other severe storms are also possible in parts of the northern Plains, central Appalachians, and Mid-Atlantic. ...20Z Update... Both the Slight and Enhanced risks were expanded slightly west-southwestward in eastern SD with this update. Here, the latest guidance has come into relatively good agreement, depicting convective development ahead of a gradually evolving surface low into this evening. Very steep deep-layer lapse rates/extreme surface-based buoyancy and 40-50 kt of effective shear will promote supercells/organized clusters capable of producing large hail and severe wind gusts. Farther east, the Marginal risk was expanded southward across southeastern NC into northern SC. Strong heating/destabilization will promote damaging wind gusts with any small thunderstorm clusters that evolve. ..Weinman.. 07/27/2025 .PREV DISCUSSION... /ISSUED 1200 PM CDT Sun Jul 27 2025/ ...Upper Midwest/western Great Lakes including MN/eastern SD... A convectively enhanced mid-level shortwave trough over northern/eastern North Dakota will continue generally eastward toward northern Minnesota, with a modest flattening of the downstream upper-level ridge into tonight. A modest deepening of the surface low will occur across eastern South Dakota toward the southwest Minnesota border vicinity, with intense thunderstorm development later today generally expected to focus along the southeastward-advancing front, although differential heating and a convectively aided cluster/possible MCV across northeast South Dakota at midday may also be factors. Given the strong buoyancy near/south of the front, and very steep lapse rates/elevated mixed layer impinging from the west-southwest, modestly strong wind profiles will be sufficient for intense supercell development with initial storms, including large hail potential (higher magnitudes possible especially eastern South Dakotas and southwest Minnesota) and some tornado risk. Multiple southeastward-moving clusters should evolve this evening with an increasing likelihood of damaging wind across southern Minnesota into western/northern Wisconsin. Portions of the region have been upgraded to an Enhanced Risk. ...Mid-Atlantic/Central Appalachians... Scattered afternoon thunderstorms will continue to increase regionally. Similar to previous days, mid-level lapse rates will be weak and considerable mid-level moisture will keep the overall potential somewhat limited/isolated. However, the strongest cells will be capable of occasional gusty/damaging winds, with a somewhat higher probability of wind damage seemingly existing across eastern Virginia where buoyancy will be greater. ...Montana... Strong heating will occur this afternoon across much of central/eastern Montana, where deep boundary-layer mixing will lead to inverted-v profiles. Scattered thunderstorms are forecast to develop along a corridor from southwest into central Montana by late afternoon. These high-based storms may pose a risk of a few severe-caliber wind gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jul 27 2025 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN/CENTRAL MINNESOTA AND FAR EASTERN SOUTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC STATES... ...SUMMARY... Severe thunderstorms are expected this afternoon and evening across parts of the Upper Midwest to western Great Lakes. Other severe storms are also possible in parts of the northern Plains, central Appalachians, and Mid-Atlantic. ...20Z Update... Both the Slight and Enhanced risks were expanded slightly west-southwestward in eastern SD with this update. Here, the latest guidance has come into relatively good agreement, depicting convective development ahead of a gradually evolving surface low into this evening. Very steep deep-layer lapse rates/extreme surface-based buoyancy and 40-50 kt of effective shear will promote supercells/organized clusters capable of producing large hail and severe wind gusts. Farther east, the Marginal risk was expanded southward across southeastern NC into northern SC. Strong heating/destabilization will promote damaging wind gusts with any small thunderstorm clusters that evolve. ..Weinman.. 07/27/2025 .PREV DISCUSSION... /ISSUED 1200 PM CDT Sun Jul 27 2025/ ...Upper Midwest/western Great Lakes including MN/eastern SD... A convectively enhanced mid-level shortwave trough over northern/eastern North Dakota will continue generally eastward toward northern Minnesota, with a modest flattening of the downstream upper-level ridge into tonight. A modest deepening of the surface low will occur across eastern South Dakota toward the southwest Minnesota border vicinity, with intense thunderstorm development later today generally expected to focus along the southeastward-advancing front, although differential heating and a convectively aided cluster/possible MCV across northeast South Dakota at midday may also be factors. Given the strong buoyancy near/south of the front, and very steep lapse rates/elevated mixed layer impinging from the west-southwest, modestly strong wind profiles will be sufficient for intense supercell development with initial storms, including large hail potential (higher magnitudes possible especially eastern South Dakotas and southwest Minnesota) and some tornado risk. Multiple southeastward-moving clusters should evolve this evening with an increasing likelihood of damaging wind across southern Minnesota into western/northern Wisconsin. Portions of the region have been upgraded to an Enhanced Risk. ...Mid-Atlantic/Central Appalachians... Scattered afternoon thunderstorms will continue to increase regionally. Similar to previous days, mid-level lapse rates will be weak and considerable mid-level moisture will keep the overall potential somewhat limited/isolated. However, the strongest cells will be capable of occasional gusty/damaging winds, with a somewhat higher probability of wind damage seemingly existing across eastern Virginia where buoyancy will be greater. ...Montana... Strong heating will occur this afternoon across much of central/eastern Montana, where deep boundary-layer mixing will lead to inverted-v profiles. Scattered thunderstorms are forecast to develop along a corridor from southwest into central Montana by late afternoon. These high-based storms may pose a risk of a few severe-caliber wind gusts. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jul 27 2025 Valid 272000Z - 281200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN/CENTRAL MINNESOTA AND FAR EASTERN SOUTH DAKOTA... ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-ATLANTIC STATES... ...SUMMARY... Severe thunderstorms are expected this afternoon and evening across parts of the Upper Midwest to western Great Lakes. Other severe storms are also possible in parts of the northern Plains, central Appalachians, and Mid-Atlantic. ...20Z Update... Both the Slight and Enhanced risks were expanded slightly west-southwestward in eastern SD with this update. Here, the latest guidance has come into relatively good agreement, depicting convective development ahead of a gradually evolving surface low into this evening. Very steep deep-layer lapse rates/extreme surface-based buoyancy and 40-50 kt of effective shear will promote supercells/organized clusters capable of producing large hail and severe wind gusts. Farther east, the Marginal risk was expanded southward across southeastern NC into northern SC. Strong heating/destabilization will promote damaging wind gusts with any small thunderstorm clusters that evolve. ..Weinman.. 07/27/2025 .PREV DISCUSSION... /ISSUED 1200 PM CDT Sun Jul 27 2025/ ...Upper Midwest/western Great Lakes including MN/eastern SD... A convectively enhanced mid-level shortwave trough over northern/eastern North Dakota will continue generally eastward toward northern Minnesota, with a modest flattening of the downstream upper-level ridge into tonight. A modest deepening of the surface low will occur across eastern South Dakota toward the southwest Minnesota border vicinity, with intense thunderstorm development later today generally expected to focus along the southeastward-advancing front, although differential heating and a convectively aided cluster/possible MCV across northeast South Dakota at midday may also be factors. Given the strong buoyancy near/south of the front, and very steep lapse rates/elevated mixed layer impinging from the west-southwest, modestly strong wind profiles will be sufficient for intense supercell development with initial storms, including large hail potential (higher magnitudes possible especially eastern South Dakotas and southwest Minnesota) and some tornado risk. Multiple southeastward-moving clusters should evolve this evening with an increasing likelihood of damaging wind across southern Minnesota into western/northern Wisconsin. Portions of the region have been upgraded to an Enhanced Risk. ...Mid-Atlantic/Central Appalachians... Scattered afternoon thunderstorms will continue to increase regionally. Similar to previous days, mid-level lapse rates will be weak and considerable mid-level moisture will keep the overall potential somewhat limited/isolated. However, the strongest cells will be capable of occasional gusty/damaging winds, with a somewhat higher probability of wind damage seemingly existing across eastern Virginia where buoyancy will be greater. ...Montana... Strong heating will occur this afternoon across much of central/eastern Montana, where deep boundary-layer mixing will lead to inverted-v profiles. Scattered thunderstorms are forecast to develop along a corridor from southwest into central Montana by late afternoon. These high-based storms may pose a risk of a few severe-caliber wind gusts. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 PM CDT Sun Jul 27 2025 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM MONTANA INTO THE CENTRAL HIGH PLAINS EASTWARD TO PARTS OF THE MID-MISSISSIPPI VALLEY... ...SUMMARY... Severe thunderstorms are possible from southern Montana into the central High Plains as well as parts of the Mid-Missouri and Mid-Mississippi Valleys on Tuesday. ...Central Plains to Mid-MS Valley vicinity... Another day of severe storms/MCS potential will exist on Tuesday. However, uncertainty remains high given several rounds of severe storms expected over the coming days prior to Tuesday/Day 3. However, the severe risk appears to be shunted a bit south compared to prior days, with southern SD/NE into IA and southern WI/northern IL the more likely corridor for severe potential on Tuesday. Convection may be ongoing across parts of WI/IL Tuesday morning. Any outflow associated with this system could become a focus for redevelopment during the afternoon. Further west, a surface low will be located over southern NE/KS with a cold front somewhere in the vicinity of northeast CO/western NE Tuesday morning. The surface low/front and where the cold front possibly intersects the outflow boundary further east also will be a focus for severe thunderstorm development. Stronger westerly flow aloft will likely remain somewhat displaced from the corridor of favorable thermodynamics/low-level moisture and surface boundaries. Nevertheless, storms producing large hail and damaging/severe gusts appear likely somewhere within the broad region from the central Plains to the Mid-MS/Lake Michigan vicinity. Given uncertainty, will maintain the Marginal risk (level 1 of 5), but a corridor of greater potential will likely emerge in the coming day or two. ...MT into the Central High Plains... Abundant boundary layer moisture will persist even in the wake of the surface front from MT into eastern WY, western SD/NE and northeast CO. The low-level upslope flow regime will support thunderstorm development near higher terrain initially. This activity should intensify as it moves off higher terrain into a corridor of moderate to strong instability by late afternoon/early evening. Effective shear will be strongest across MT/northeast WY/western SD (around 40 kt), weakening with southward extent into northeast CO (around 20-25 kt). Steep lapse rates and elongated/straight hodographs suggest isolated large hail will be possible. Meanwhile, steep low-level lapse rates/mixing to near 700 mb should support isolated strong/severe gusts as well. ...Lower MI/IN/OH vicinity... A decaying MCS and associated MCV may be located over WI/IL Tuesday morning. This feature could develop east/southeast with time and become a focus for thunderstorm develop during the afternoon or evening within the very moist and strongly unstable airmass across the region. However, forecast guidance is not consistent with this scenario, possibly due to nebulous large-scale ascent. Given uncertainty/conditional nature of this potential risk, will hold off on expanding severe probabilities further east, but a risk area may be needed in later outlooks depending on trends. ..Leitman.. 07/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 PM CDT Sun Jul 27 2025 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM MONTANA INTO THE CENTRAL HIGH PLAINS EASTWARD TO PARTS OF THE MID-MISSISSIPPI VALLEY... ...SUMMARY... Severe thunderstorms are possible from southern Montana into the central High Plains as well as parts of the Mid-Missouri and Mid-Mississippi Valleys on Tuesday. ...Central Plains to Mid-MS Valley vicinity... Another day of severe storms/MCS potential will exist on Tuesday. However, uncertainty remains high given several rounds of severe storms expected over the coming days prior to Tuesday/Day 3. However, the severe risk appears to be shunted a bit south compared to prior days, with southern SD/NE into IA and southern WI/northern IL the more likely corridor for severe potential on Tuesday. Convection may be ongoing across parts of WI/IL Tuesday morning. Any outflow associated with this system could become a focus for redevelopment during the afternoon. Further west, a surface low will be located over southern NE/KS with a cold front somewhere in the vicinity of northeast CO/western NE Tuesday morning. The surface low/front and where the cold front possibly intersects the outflow boundary further east also will be a focus for severe thunderstorm development. Stronger westerly flow aloft will likely remain somewhat displaced from the corridor of favorable thermodynamics/low-level moisture and surface boundaries. Nevertheless, storms producing large hail and damaging/severe gusts appear likely somewhere within the broad region from the central Plains to the Mid-MS/Lake Michigan vicinity. Given uncertainty, will maintain the Marginal risk (level 1 of 5), but a corridor of greater potential will likely emerge in the coming day or two. ...MT into the Central High Plains... Abundant boundary layer moisture will persist even in the wake of the surface front from MT into eastern WY, western SD/NE and northeast CO. The low-level upslope flow regime will support thunderstorm development near higher terrain initially. This activity should intensify as it moves off higher terrain into a corridor of moderate to strong instability by late afternoon/early evening. Effective shear will be strongest across MT/northeast WY/western SD (around 40 kt), weakening with southward extent into northeast CO (around 20-25 kt). Steep lapse rates and elongated/straight hodographs suggest isolated large hail will be possible. Meanwhile, steep low-level lapse rates/mixing to near 700 mb should support isolated strong/severe gusts as well. ...Lower MI/IN/OH vicinity... A decaying MCS and associated MCV may be located over WI/IL Tuesday morning. This feature could develop east/southeast with time and become a focus for thunderstorm develop during the afternoon or evening within the very moist and strongly unstable airmass across the region. However, forecast guidance is not consistent with this scenario, possibly due to nebulous large-scale ascent. Given uncertainty/conditional nature of this potential risk, will hold off on expanding severe probabilities further east, but a risk area may be needed in later outlooks depending on trends. ..Leitman.. 07/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 PM CDT Sun Jul 27 2025 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM MONTANA INTO THE CENTRAL HIGH PLAINS EASTWARD TO PARTS OF THE MID-MISSISSIPPI VALLEY... ...SUMMARY... Severe thunderstorms are possible from southern Montana into the central High Plains as well as parts of the Mid-Missouri and Mid-Mississippi Valleys on Tuesday. ...Central Plains to Mid-MS Valley vicinity... Another day of severe storms/MCS potential will exist on Tuesday. However, uncertainty remains high given several rounds of severe storms expected over the coming days prior to Tuesday/Day 3. However, the severe risk appears to be shunted a bit south compared to prior days, with southern SD/NE into IA and southern WI/northern IL the more likely corridor for severe potential on Tuesday. Convection may be ongoing across parts of WI/IL Tuesday morning. Any outflow associated with this system could become a focus for redevelopment during the afternoon. Further west, a surface low will be located over southern NE/KS with a cold front somewhere in the vicinity of northeast CO/western NE Tuesday morning. The surface low/front and where the cold front possibly intersects the outflow boundary further east also will be a focus for severe thunderstorm development. Stronger westerly flow aloft will likely remain somewhat displaced from the corridor of favorable thermodynamics/low-level moisture and surface boundaries. Nevertheless, storms producing large hail and damaging/severe gusts appear likely somewhere within the broad region from the central Plains to the Mid-MS/Lake Michigan vicinity. Given uncertainty, will maintain the Marginal risk (level 1 of 5), but a corridor of greater potential will likely emerge in the coming day or two. ...MT into the Central High Plains... Abundant boundary layer moisture will persist even in the wake of the surface front from MT into eastern WY, western SD/NE and northeast CO. The low-level upslope flow regime will support thunderstorm development near higher terrain initially. This activity should intensify as it moves off higher terrain into a corridor of moderate to strong instability by late afternoon/early evening. Effective shear will be strongest across MT/northeast WY/western SD (around 40 kt), weakening with southward extent into northeast CO (around 20-25 kt). Steep lapse rates and elongated/straight hodographs suggest isolated large hail will be possible. Meanwhile, steep low-level lapse rates/mixing to near 700 mb should support isolated strong/severe gusts as well. ...Lower MI/IN/OH vicinity... A decaying MCS and associated MCV may be located over WI/IL Tuesday morning. This feature could develop east/southeast with time and become a focus for thunderstorm develop during the afternoon or evening within the very moist and strongly unstable airmass across the region. However, forecast guidance is not consistent with this scenario, possibly due to nebulous large-scale ascent. Given uncertainty/conditional nature of this potential risk, will hold off on expanding severe probabilities further east, but a risk area may be needed in later outlooks depending on trends. ..Leitman.. 07/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 PM CDT Sun Jul 27 2025 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM MONTANA INTO THE CENTRAL HIGH PLAINS EASTWARD TO PARTS OF THE MID-MISSISSIPPI VALLEY... ...SUMMARY... Severe thunderstorms are possible from southern Montana into the central High Plains as well as parts of the Mid-Missouri and Mid-Mississippi Valleys on Tuesday. ...Central Plains to Mid-MS Valley vicinity... Another day of severe storms/MCS potential will exist on Tuesday. However, uncertainty remains high given several rounds of severe storms expected over the coming days prior to Tuesday/Day 3. However, the severe risk appears to be shunted a bit south compared to prior days, with southern SD/NE into IA and southern WI/northern IL the more likely corridor for severe potential on Tuesday. Convection may be ongoing across parts of WI/IL Tuesday morning. Any outflow associated with this system could become a focus for redevelopment during the afternoon. Further west, a surface low will be located over southern NE/KS with a cold front somewhere in the vicinity of northeast CO/western NE Tuesday morning. The surface low/front and where the cold front possibly intersects the outflow boundary further east also will be a focus for severe thunderstorm development. Stronger westerly flow aloft will likely remain somewhat displaced from the corridor of favorable thermodynamics/low-level moisture and surface boundaries. Nevertheless, storms producing large hail and damaging/severe gusts appear likely somewhere within the broad region from the central Plains to the Mid-MS/Lake Michigan vicinity. Given uncertainty, will maintain the Marginal risk (level 1 of 5), but a corridor of greater potential will likely emerge in the coming day or two. ...MT into the Central High Plains... Abundant boundary layer moisture will persist even in the wake of the surface front from MT into eastern WY, western SD/NE and northeast CO. The low-level upslope flow regime will support thunderstorm development near higher terrain initially. This activity should intensify as it moves off higher terrain into a corridor of moderate to strong instability by late afternoon/early evening. Effective shear will be strongest across MT/northeast WY/western SD (around 40 kt), weakening with southward extent into northeast CO (around 20-25 kt). Steep lapse rates and elongated/straight hodographs suggest isolated large hail will be possible. Meanwhile, steep low-level lapse rates/mixing to near 700 mb should support isolated strong/severe gusts as well. ...Lower MI/IN/OH vicinity... A decaying MCS and associated MCV may be located over WI/IL Tuesday morning. This feature could develop east/southeast with time and become a focus for thunderstorm develop during the afternoon or evening within the very moist and strongly unstable airmass across the region. However, forecast guidance is not consistent with this scenario, possibly due to nebulous large-scale ascent. Given uncertainty/conditional nature of this potential risk, will hold off on expanding severe probabilities further east, but a risk area may be needed in later outlooks depending on trends. ..Leitman.. 07/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 PM CDT Sun Jul 27 2025 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM MONTANA INTO THE CENTRAL HIGH PLAINS EASTWARD TO PARTS OF THE MID-MISSISSIPPI VALLEY... ...SUMMARY... Severe thunderstorms are possible from southern Montana into the central High Plains as well as parts of the Mid-Missouri and Mid-Mississippi Valleys on Tuesday. ...Central Plains to Mid-MS Valley vicinity... Another day of severe storms/MCS potential will exist on Tuesday. However, uncertainty remains high given several rounds of severe storms expected over the coming days prior to Tuesday/Day 3. However, the severe risk appears to be shunted a bit south compared to prior days, with southern SD/NE into IA and southern WI/northern IL the more likely corridor for severe potential on Tuesday. Convection may be ongoing across parts of WI/IL Tuesday morning. Any outflow associated with this system could become a focus for redevelopment during the afternoon. Further west, a surface low will be located over southern NE/KS with a cold front somewhere in the vicinity of northeast CO/western NE Tuesday morning. The surface low/front and where the cold front possibly intersects the outflow boundary further east also will be a focus for severe thunderstorm development. Stronger westerly flow aloft will likely remain somewhat displaced from the corridor of favorable thermodynamics/low-level moisture and surface boundaries. Nevertheless, storms producing large hail and damaging/severe gusts appear likely somewhere within the broad region from the central Plains to the Mid-MS/Lake Michigan vicinity. Given uncertainty, will maintain the Marginal risk (level 1 of 5), but a corridor of greater potential will likely emerge in the coming day or two. ...MT into the Central High Plains... Abundant boundary layer moisture will persist even in the wake of the surface front from MT into eastern WY, western SD/NE and northeast CO. The low-level upslope flow regime will support thunderstorm development near higher terrain initially. This activity should intensify as it moves off higher terrain into a corridor of moderate to strong instability by late afternoon/early evening. Effective shear will be strongest across MT/northeast WY/western SD (around 40 kt), weakening with southward extent into northeast CO (around 20-25 kt). Steep lapse rates and elongated/straight hodographs suggest isolated large hail will be possible. Meanwhile, steep low-level lapse rates/mixing to near 700 mb should support isolated strong/severe gusts as well. ...Lower MI/IN/OH vicinity... A decaying MCS and associated MCV may be located over WI/IL Tuesday morning. This feature could develop east/southeast with time and become a focus for thunderstorm develop during the afternoon or evening within the very moist and strongly unstable airmass across the region. However, forecast guidance is not consistent with this scenario, possibly due to nebulous large-scale ascent. Given uncertainty/conditional nature of this potential risk, will hold off on expanding severe probabilities further east, but a risk area may be needed in later outlooks depending on trends. ..Leitman.. 07/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 PM CDT Sun Jul 27 2025 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM MONTANA INTO THE CENTRAL HIGH PLAINS EASTWARD TO PARTS OF THE MID-MISSISSIPPI VALLEY... ...SUMMARY... Severe thunderstorms are possible from southern Montana into the central High Plains as well as parts of the Mid-Missouri and Mid-Mississippi Valleys on Tuesday. ...Central Plains to Mid-MS Valley vicinity... Another day of severe storms/MCS potential will exist on Tuesday. However, uncertainty remains high given several rounds of severe storms expected over the coming days prior to Tuesday/Day 3. However, the severe risk appears to be shunted a bit south compared to prior days, with southern SD/NE into IA and southern WI/northern IL the more likely corridor for severe potential on Tuesday. Convection may be ongoing across parts of WI/IL Tuesday morning. Any outflow associated with this system could become a focus for redevelopment during the afternoon. Further west, a surface low will be located over southern NE/KS with a cold front somewhere in the vicinity of northeast CO/western NE Tuesday morning. The surface low/front and where the cold front possibly intersects the outflow boundary further east also will be a focus for severe thunderstorm development. Stronger westerly flow aloft will likely remain somewhat displaced from the corridor of favorable thermodynamics/low-level moisture and surface boundaries. Nevertheless, storms producing large hail and damaging/severe gusts appear likely somewhere within the broad region from the central Plains to the Mid-MS/Lake Michigan vicinity. Given uncertainty, will maintain the Marginal risk (level 1 of 5), but a corridor of greater potential will likely emerge in the coming day or two. ...MT into the Central High Plains... Abundant boundary layer moisture will persist even in the wake of the surface front from MT into eastern WY, western SD/NE and northeast CO. The low-level upslope flow regime will support thunderstorm development near higher terrain initially. This activity should intensify as it moves off higher terrain into a corridor of moderate to strong instability by late afternoon/early evening. Effective shear will be strongest across MT/northeast WY/western SD (around 40 kt), weakening with southward extent into northeast CO (around 20-25 kt). Steep lapse rates and elongated/straight hodographs suggest isolated large hail will be possible. Meanwhile, steep low-level lapse rates/mixing to near 700 mb should support isolated strong/severe gusts as well. ...Lower MI/IN/OH vicinity... A decaying MCS and associated MCV may be located over WI/IL Tuesday morning. This feature could develop east/southeast with time and become a focus for thunderstorm develop during the afternoon or evening within the very moist and strongly unstable airmass across the region. However, forecast guidance is not consistent with this scenario, possibly due to nebulous large-scale ascent. Given uncertainty/conditional nature of this potential risk, will hold off on expanding severe probabilities further east, but a risk area may be needed in later outlooks depending on trends. ..Leitman.. 07/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 PM CDT Sun Jul 27 2025 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM MONTANA INTO THE CENTRAL HIGH PLAINS EASTWARD TO PARTS OF THE MID-MISSISSIPPI VALLEY... ...SUMMARY... Severe thunderstorms are possible from southern Montana into the central High Plains as well as parts of the Mid-Missouri and Mid-Mississippi Valleys on Tuesday. ...Central Plains to Mid-MS Valley vicinity... Another day of severe storms/MCS potential will exist on Tuesday. However, uncertainty remains high given several rounds of severe storms expected over the coming days prior to Tuesday/Day 3. However, the severe risk appears to be shunted a bit south compared to prior days, with southern SD/NE into IA and southern WI/northern IL the more likely corridor for severe potential on Tuesday. Convection may be ongoing across parts of WI/IL Tuesday morning. Any outflow associated with this system could become a focus for redevelopment during the afternoon. Further west, a surface low will be located over southern NE/KS with a cold front somewhere in the vicinity of northeast CO/western NE Tuesday morning. The surface low/front and where the cold front possibly intersects the outflow boundary further east also will be a focus for severe thunderstorm development. Stronger westerly flow aloft will likely remain somewhat displaced from the corridor of favorable thermodynamics/low-level moisture and surface boundaries. Nevertheless, storms producing large hail and damaging/severe gusts appear likely somewhere within the broad region from the central Plains to the Mid-MS/Lake Michigan vicinity. Given uncertainty, will maintain the Marginal risk (level 1 of 5), but a corridor of greater potential will likely emerge in the coming day or two. ...MT into the Central High Plains... Abundant boundary layer moisture will persist even in the wake of the surface front from MT into eastern WY, western SD/NE and northeast CO. The low-level upslope flow regime will support thunderstorm development near higher terrain initially. This activity should intensify as it moves off higher terrain into a corridor of moderate to strong instability by late afternoon/early evening. Effective shear will be strongest across MT/northeast WY/western SD (around 40 kt), weakening with southward extent into northeast CO (around 20-25 kt). Steep lapse rates and elongated/straight hodographs suggest isolated large hail will be possible. Meanwhile, steep low-level lapse rates/mixing to near 700 mb should support isolated strong/severe gusts as well. ...Lower MI/IN/OH vicinity... A decaying MCS and associated MCV may be located over WI/IL Tuesday morning. This feature could develop east/southeast with time and become a focus for thunderstorm develop during the afternoon or evening within the very moist and strongly unstable airmass across the region. However, forecast guidance is not consistent with this scenario, possibly due to nebulous large-scale ascent. Given uncertainty/conditional nature of this potential risk, will hold off on expanding severe probabilities further east, but a risk area may be needed in later outlooks depending on trends. ..Leitman.. 07/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 PM CDT Sun Jul 27 2025 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM MONTANA INTO THE CENTRAL HIGH PLAINS EASTWARD TO PARTS OF THE MID-MISSISSIPPI VALLEY... ...SUMMARY... Severe thunderstorms are possible from southern Montana into the central High Plains as well as parts of the Mid-Missouri and Mid-Mississippi Valleys on Tuesday. ...Central Plains to Mid-MS Valley vicinity... Another day of severe storms/MCS potential will exist on Tuesday. However, uncertainty remains high given several rounds of severe storms expected over the coming days prior to Tuesday/Day 3. However, the severe risk appears to be shunted a bit south compared to prior days, with southern SD/NE into IA and southern WI/northern IL the more likely corridor for severe potential on Tuesday. Convection may be ongoing across parts of WI/IL Tuesday morning. Any outflow associated with this system could become a focus for redevelopment during the afternoon. Further west, a surface low will be located over southern NE/KS with a cold front somewhere in the vicinity of northeast CO/western NE Tuesday morning. The surface low/front and where the cold front possibly intersects the outflow boundary further east also will be a focus for severe thunderstorm development. Stronger westerly flow aloft will likely remain somewhat displaced from the corridor of favorable thermodynamics/low-level moisture and surface boundaries. Nevertheless, storms producing large hail and damaging/severe gusts appear likely somewhere within the broad region from the central Plains to the Mid-MS/Lake Michigan vicinity. Given uncertainty, will maintain the Marginal risk (level 1 of 5), but a corridor of greater potential will likely emerge in the coming day or two. ...MT into the Central High Plains... Abundant boundary layer moisture will persist even in the wake of the surface front from MT into eastern WY, western SD/NE and northeast CO. The low-level upslope flow regime will support thunderstorm development near higher terrain initially. This activity should intensify as it moves off higher terrain into a corridor of moderate to strong instability by late afternoon/early evening. Effective shear will be strongest across MT/northeast WY/western SD (around 40 kt), weakening with southward extent into northeast CO (around 20-25 kt). Steep lapse rates and elongated/straight hodographs suggest isolated large hail will be possible. Meanwhile, steep low-level lapse rates/mixing to near 700 mb should support isolated strong/severe gusts as well. ...Lower MI/IN/OH vicinity... A decaying MCS and associated MCV may be located over WI/IL Tuesday morning. This feature could develop east/southeast with time and become a focus for thunderstorm develop during the afternoon or evening within the very moist and strongly unstable airmass across the region. However, forecast guidance is not consistent with this scenario, possibly due to nebulous large-scale ascent. Given uncertainty/conditional nature of this potential risk, will hold off on expanding severe probabilities further east, but a risk area may be needed in later outlooks depending on trends. ..Leitman.. 07/27/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0218 PM CDT Sun Jul 27 2025 Valid 291200Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM MONTANA INTO THE CENTRAL HIGH PLAINS EASTWARD TO PARTS OF THE MID-MISSISSIPPI VALLEY... ...SUMMARY... Severe thunderstorms are possible from southern Montana into the central High Plains as well as parts of the Mid-Missouri and Mid-Mississippi Valleys on Tuesday. ...Central Plains to Mid-MS Valley vicinity... Another day of severe storms/MCS potential will exist on Tuesday. However, uncertainty remains high given several rounds of severe storms expected over the coming days prior to Tuesday/Day 3. However, the severe risk appears to be shunted a bit south compared to prior days, with southern SD/NE into IA and southern WI/northern IL the more likely corridor for severe potential on Tuesday. Convection may be ongoing across parts of WI/IL Tuesday morning. Any outflow associated with this system could become a focus for redevelopment during the afternoon. Further west, a surface low will be located over southern NE/KS with a cold front somewhere in the vicinity of northeast CO/western NE Tuesday morning. The surface low/front and where the cold front possibly intersects the outflow boundary further east also will be a focus for severe thunderstorm development. Stronger westerly flow aloft will likely remain somewhat displaced from the corridor of favorable thermodynamics/low-level moisture and surface boundaries. Nevertheless, storms producing large hail and damaging/severe gusts appear likely somewhere within the broad region from the central Plains to the Mid-MS/Lake Michigan vicinity. Given uncertainty, will maintain the Marginal risk (level 1 of 5), but a corridor of greater potential will likely emerge in the coming day or two. ...MT into the Central High Plains... Abundant boundary layer moisture will persist even in the wake of the surface front from MT into eastern WY, western SD/NE and northeast CO. The low-level upslope flow regime will support thunderstorm development near higher terrain initially. This activity should intensify as it moves off higher terrain into a corridor of moderate to strong instability by late afternoon/early evening. Effective shear will be strongest across MT/northeast WY/western SD (around 40 kt), weakening with southward extent into northeast CO (around 20-25 kt). Steep lapse rates and elongated/straight hodographs suggest isolated large hail will be possible. Meanwhile, steep low-level lapse rates/mixing to near 700 mb should support isolated strong/severe gusts as well. ...Lower MI/IN/OH vicinity... A decaying MCS and associated MCV may be located over WI/IL Tuesday morning. This feature could develop east/southeast with time and become a focus for thunderstorm develop during the afternoon or evening within the very moist and strongly unstable airmass across the region. However, forecast guidance is not consistent with this scenario, possibly due to nebulous large-scale ascent. Given uncertainty/conditional nature of this potential risk, will hold off on expanding severe probabilities further east, but a risk area may be needed in later outlooks depending on trends. ..Leitman.. 07/27/2025 Read more