Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1151 AM CDT Mon Jul 28 2025 Valid 281700Z - 291200Z ...17z Update... A mix of wet/dry thunderstorms with dry lightning potential remains likely this afternoon and evening from northern CA into southern OR and western ID. CAM guidance has trended stronger with isolated convection over the mountains of northern CA. With deep inverted-v profiles, a few dry strikes are possible. IsoDryT highlights have been expanded southward. See the previous discussion for more info. ..Lyons.. 07/28/2025 .PREV DISCUSSION... /ISSUED 0152 AM CDT Mon Jul 28 2025/ ...Synopsis... An upper ridge will dominate the CONUS today, with mid-level moisture poised to pivot around the upper ridge through the period. By afternoon, a deep, dry boundary layer (potentially extending to 500 mb) will develop in advance of thunderstorm initiation. Forecast soundings show inverted-v profiles, suggesting that at least a mix of wet and dry thunderstorms will develop across portions of the Pacific Northwest into the Northern Rockies. Given dry fuels over the region, isolated dry thunderstorm highlights were introduced given the possibility of lightning-induced ignitions. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1151 AM CDT Mon Jul 28 2025 Valid 281700Z - 291200Z ...17z Update... A mix of wet/dry thunderstorms with dry lightning potential remains likely this afternoon and evening from northern CA into southern OR and western ID. CAM guidance has trended stronger with isolated convection over the mountains of northern CA. With deep inverted-v profiles, a few dry strikes are possible. IsoDryT highlights have been expanded southward. See the previous discussion for more info. ..Lyons.. 07/28/2025 .PREV DISCUSSION... /ISSUED 0152 AM CDT Mon Jul 28 2025/ ...Synopsis... An upper ridge will dominate the CONUS today, with mid-level moisture poised to pivot around the upper ridge through the period. By afternoon, a deep, dry boundary layer (potentially extending to 500 mb) will develop in advance of thunderstorm initiation. Forecast soundings show inverted-v profiles, suggesting that at least a mix of wet and dry thunderstorms will develop across portions of the Pacific Northwest into the Northern Rockies. Given dry fuels over the region, isolated dry thunderstorm highlights were introduced given the possibility of lightning-induced ignitions. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1151 AM CDT Mon Jul 28 2025 Valid 281700Z - 291200Z ...17z Update... A mix of wet/dry thunderstorms with dry lightning potential remains likely this afternoon and evening from northern CA into southern OR and western ID. CAM guidance has trended stronger with isolated convection over the mountains of northern CA. With deep inverted-v profiles, a few dry strikes are possible. IsoDryT highlights have been expanded southward. See the previous discussion for more info. ..Lyons.. 07/28/2025 .PREV DISCUSSION... /ISSUED 0152 AM CDT Mon Jul 28 2025/ ...Synopsis... An upper ridge will dominate the CONUS today, with mid-level moisture poised to pivot around the upper ridge through the period. By afternoon, a deep, dry boundary layer (potentially extending to 500 mb) will develop in advance of thunderstorm initiation. Forecast soundings show inverted-v profiles, suggesting that at least a mix of wet and dry thunderstorms will develop across portions of the Pacific Northwest into the Northern Rockies. Given dry fuels over the region, isolated dry thunderstorm highlights were introduced given the possibility of lightning-induced ignitions. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0550 Status Updates
STATUS REPORT ON WW 550 THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA. ..KERR..07/28/25 ATTN...WFO...BIS... STATUS REPORT FOR WS 550 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NDC001-011-015-025-029-037-041-043-047-051-057-059-065-085-087- 089-281740- ND . NORTH DAKOTA COUNTIES INCLUDED ARE ADAMS BOWMAN BURLEIGH DUNN EMMONS GRANT HETTINGER KIDDER LOGAN MCINTOSH MERCER MORTON OLIVER SIOUX SLOPE STARK THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES. Read more

Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1136 AM CDT MON JUL 28 2025 ...Severe thunderstorms expected over parts of the northern Plains into the upper Mississippi Valley this afternoon and tonight... * LOCATIONS... Southern Minnesota Eastern South Dakota Northern Iowa * HAZARDS... Widespread damaging winds, some hurricane force A couple of tornadoes Isolated large hail up to baseball size * SUMMARY... Severe storm clusters are expected to form this afternoon in South Dakota and then spread southeastward into Minnesota and Iowa through tonight. Swaths of damaging winds, potentially 75-90 mph, a few tornadoes and isolated large hail will all be possible. Preparedness actions... Review your severe weather safety procedures for the possibility of dangerous weather today. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A watch means that conditions are favorable for severe thunderstorms over the next several hours. If a severe thunderstorm warning is issued for your area, move to a place of safety, ideally in an interior room on the lowest floor of a sturdy building. && ..Thompson.. 07/28/2025 Read more

Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1136 AM CDT MON JUL 28 2025 ...Severe thunderstorms expected over parts of the northern Plains into the upper Mississippi Valley this afternoon and tonight... * LOCATIONS... Southern Minnesota Eastern South Dakota Northern Iowa * HAZARDS... Widespread damaging winds, some hurricane force A couple of tornadoes Isolated large hail up to baseball size * SUMMARY... Severe storm clusters are expected to form this afternoon in South Dakota and then spread southeastward into Minnesota and Iowa through tonight. Swaths of damaging winds, potentially 75-90 mph, a few tornadoes and isolated large hail will all be possible. Preparedness actions... Review your severe weather safety procedures for the possibility of dangerous weather today. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A watch means that conditions are favorable for severe thunderstorms over the next several hours. If a severe thunderstorm warning is issued for your area, move to a place of safety, ideally in an interior room on the lowest floor of a sturdy building. && ..Thompson.. 07/28/2025 Read more

Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1136 AM CDT MON JUL 28 2025 ...Severe thunderstorms expected over parts of the northern Plains into the upper Mississippi Valley this afternoon and tonight... * LOCATIONS... Southern Minnesota Eastern South Dakota Northern Iowa * HAZARDS... Widespread damaging winds, some hurricane force A couple of tornadoes Isolated large hail up to baseball size * SUMMARY... Severe storm clusters are expected to form this afternoon in South Dakota and then spread southeastward into Minnesota and Iowa through tonight. Swaths of damaging winds, potentially 75-90 mph, a few tornadoes and isolated large hail will all be possible. Preparedness actions... Review your severe weather safety procedures for the possibility of dangerous weather today. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A watch means that conditions are favorable for severe thunderstorms over the next several hours. If a severe thunderstorm warning is issued for your area, move to a place of safety, ideally in an interior room on the lowest floor of a sturdy building. && ..Thompson.. 07/28/2025 Read more

Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1136 AM CDT MON JUL 28 2025 ...Severe thunderstorms expected over parts of the northern Plains into the upper Mississippi Valley this afternoon and tonight... * LOCATIONS... Southern Minnesota Eastern South Dakota Northern Iowa * HAZARDS... Widespread damaging winds, some hurricane force A couple of tornadoes Isolated large hail up to baseball size * SUMMARY... Severe storm clusters are expected to form this afternoon in South Dakota and then spread southeastward into Minnesota and Iowa through tonight. Swaths of damaging winds, potentially 75-90 mph, a few tornadoes and isolated large hail will all be possible. Preparedness actions... Review your severe weather safety procedures for the possibility of dangerous weather today. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A watch means that conditions are favorable for severe thunderstorms over the next several hours. If a severe thunderstorm warning is issued for your area, move to a place of safety, ideally in an interior room on the lowest floor of a sturdy building. && ..Thompson.. 07/28/2025 Read more

Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1136 AM CDT MON JUL 28 2025 ...Severe thunderstorms expected over parts of the northern Plains into the upper Mississippi Valley this afternoon and tonight... * LOCATIONS... Southern Minnesota Eastern South Dakota Northern Iowa * HAZARDS... Widespread damaging winds, some hurricane force A couple of tornadoes Isolated large hail up to baseball size * SUMMARY... Severe storm clusters are expected to form this afternoon in South Dakota and then spread southeastward into Minnesota and Iowa through tonight. Swaths of damaging winds, potentially 75-90 mph, a few tornadoes and isolated large hail will all be possible. Preparedness actions... Review your severe weather safety procedures for the possibility of dangerous weather today. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A watch means that conditions are favorable for severe thunderstorms over the next several hours. If a severe thunderstorm warning is issued for your area, move to a place of safety, ideally in an interior room on the lowest floor of a sturdy building. && ..Thompson.. 07/28/2025 Read more

Public Severe Weather Outlook
PUBLIC SEVERE WEATHER OUTLOOK NWS STORM PREDICTION CENTER NORMAN OK 1136 AM CDT MON JUL 28 2025 ...Severe thunderstorms expected over parts of the northern Plains into the upper Mississippi Valley this afternoon and tonight... * LOCATIONS... Southern Minnesota Eastern South Dakota Northern Iowa * HAZARDS... Widespread damaging winds, some hurricane force A couple of tornadoes Isolated large hail up to baseball size * SUMMARY... Severe storm clusters are expected to form this afternoon in South Dakota and then spread southeastward into Minnesota and Iowa through tonight. Swaths of damaging winds, potentially 75-90 mph, a few tornadoes and isolated large hail will all be possible. Preparedness actions... Review your severe weather safety procedures for the possibility of dangerous weather today. Stay tuned to NOAA Weather Radio, weather.gov, or other media for watches and warnings. A watch means that conditions are favorable for severe thunderstorms over the next several hours. If a severe thunderstorm warning is issued for your area, move to a place of safety, ideally in an interior room on the lowest floor of a sturdy building. && ..Thompson.. 07/28/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Jul 28 2025 Valid 281630Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM EASTERN SOUTH DAKOTA ACROSS SOUTHERN MINNESOTA AND NORTHERN IOWA... ...SUMMARY... Severe storm clusters are expected to form this afternoon in South Dakota and then spread southeastward into Minnesota and Iowa through tonight. Swaths of damaging winds, potentially 75-90 mph, a few tornadoes and isolated large hail will all be possible. ...Dakotas to MN/IA through tonight... Around the northern periphery of a midlevel high covering the southern Plains and Southeast, a series of embedded speed maxima will progress from MT across the Dakotas to MN through early Tuesday. Elevated convection is ongoing in association with two such speed maxima - one over ND and another moving eastward over eastern MT. At the surface, a lee cyclone is present near the SD/NE border, and a baroclinic zone arcs into northeast SD and then southeastward across southwest MN into northern IA. A prior outflow boundary (from dissipated overnight convection) will become more diffuse with time as a result of strong surface heating across IA/NE/SD within the old cold pool. The elevated convection across southern ND, and moving from MT into southwest ND, could persist in the post-frontal environment with weak warm advection atop the frontal surface. Steep midlevel lapse rates and 40-50 kt midlevel flow suggests a continued threat for occasional severe outflow gusts and isolated large hail. The more substantial severe-storm threat is expected to evolve farther southeast by mid-late afternoon along the baroclinic zone in SD, to the northeast of the lee cyclone. Strong surface heating, continued moisture advection and evapotranspiration will lead to the development of strong-extreme buoyancy (3000-4500+ J/kg MLCAPE) beneath an elevated mixed layer with 8.5-9 C/km midlevel lapse rates. Storms that form in SD are then expected to congeal into a cluster or two that will subsequently spread east-southeastward along the more northwest-southeast oriented baroclinic zone now noted in visible imagery and surface observations from southwest MN into northern IA. The thermodynamic environment will favor both intense updrafts and downdrafts, while deep-layer vertical shear will be sufficient for an organized/bowing MCS. Thus, there will be the potential for swaths of significant-severe outflow (75-90 mph), as well as isolated large hail and a few tornadoes (either with initially discrete supercells or with embedded circulations with bowing segments). ...Central MT this afternoon through early tonight... An embedded speed max will crest the ridge and move from ID to southwest MT this afternoon/evening. Residual boundary-layer dewpoints in the mid-upper 50s in the post-frontal environment, along with surface heating and the north edge of the steeper midlevel lapse rates will favor scattered thunderstorm development by early-mid afternoon (near and just northeast of the higher terrain southwest into central MT). MLCAPE of 1500-2000 J/kg, effective bulk shear in excess of 40 kt and seasonably cool midlevel temperatures suggest the potential for initial supercells with large hail (1-2.5 inches in diameter), and also the potential for upscale growth into a cluster with the attendant threat for wind damage. ..Thompson/Thornton.. 07/28/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Jul 28 2025 Valid 281630Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM EASTERN SOUTH DAKOTA ACROSS SOUTHERN MINNESOTA AND NORTHERN IOWA... ...SUMMARY... Severe storm clusters are expected to form this afternoon in South Dakota and then spread southeastward into Minnesota and Iowa through tonight. Swaths of damaging winds, potentially 75-90 mph, a few tornadoes and isolated large hail will all be possible. ...Dakotas to MN/IA through tonight... Around the northern periphery of a midlevel high covering the southern Plains and Southeast, a series of embedded speed maxima will progress from MT across the Dakotas to MN through early Tuesday. Elevated convection is ongoing in association with two such speed maxima - one over ND and another moving eastward over eastern MT. At the surface, a lee cyclone is present near the SD/NE border, and a baroclinic zone arcs into northeast SD and then southeastward across southwest MN into northern IA. A prior outflow boundary (from dissipated overnight convection) will become more diffuse with time as a result of strong surface heating across IA/NE/SD within the old cold pool. The elevated convection across southern ND, and moving from MT into southwest ND, could persist in the post-frontal environment with weak warm advection atop the frontal surface. Steep midlevel lapse rates and 40-50 kt midlevel flow suggests a continued threat for occasional severe outflow gusts and isolated large hail. The more substantial severe-storm threat is expected to evolve farther southeast by mid-late afternoon along the baroclinic zone in SD, to the northeast of the lee cyclone. Strong surface heating, continued moisture advection and evapotranspiration will lead to the development of strong-extreme buoyancy (3000-4500+ J/kg MLCAPE) beneath an elevated mixed layer with 8.5-9 C/km midlevel lapse rates. Storms that form in SD are then expected to congeal into a cluster or two that will subsequently spread east-southeastward along the more northwest-southeast oriented baroclinic zone now noted in visible imagery and surface observations from southwest MN into northern IA. The thermodynamic environment will favor both intense updrafts and downdrafts, while deep-layer vertical shear will be sufficient for an organized/bowing MCS. Thus, there will be the potential for swaths of significant-severe outflow (75-90 mph), as well as isolated large hail and a few tornadoes (either with initially discrete supercells or with embedded circulations with bowing segments). ...Central MT this afternoon through early tonight... An embedded speed max will crest the ridge and move from ID to southwest MT this afternoon/evening. Residual boundary-layer dewpoints in the mid-upper 50s in the post-frontal environment, along with surface heating and the north edge of the steeper midlevel lapse rates will favor scattered thunderstorm development by early-mid afternoon (near and just northeast of the higher terrain southwest into central MT). MLCAPE of 1500-2000 J/kg, effective bulk shear in excess of 40 kt and seasonably cool midlevel temperatures suggest the potential for initial supercells with large hail (1-2.5 inches in diameter), and also the potential for upscale growth into a cluster with the attendant threat for wind damage. ..Thompson/Thornton.. 07/28/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Jul 28 2025 Valid 281630Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM EASTERN SOUTH DAKOTA ACROSS SOUTHERN MINNESOTA AND NORTHERN IOWA... ...SUMMARY... Severe storm clusters are expected to form this afternoon in South Dakota and then spread southeastward into Minnesota and Iowa through tonight. Swaths of damaging winds, potentially 75-90 mph, a few tornadoes and isolated large hail will all be possible. ...Dakotas to MN/IA through tonight... Around the northern periphery of a midlevel high covering the southern Plains and Southeast, a series of embedded speed maxima will progress from MT across the Dakotas to MN through early Tuesday. Elevated convection is ongoing in association with two such speed maxima - one over ND and another moving eastward over eastern MT. At the surface, a lee cyclone is present near the SD/NE border, and a baroclinic zone arcs into northeast SD and then southeastward across southwest MN into northern IA. A prior outflow boundary (from dissipated overnight convection) will become more diffuse with time as a result of strong surface heating across IA/NE/SD within the old cold pool. The elevated convection across southern ND, and moving from MT into southwest ND, could persist in the post-frontal environment with weak warm advection atop the frontal surface. Steep midlevel lapse rates and 40-50 kt midlevel flow suggests a continued threat for occasional severe outflow gusts and isolated large hail. The more substantial severe-storm threat is expected to evolve farther southeast by mid-late afternoon along the baroclinic zone in SD, to the northeast of the lee cyclone. Strong surface heating, continued moisture advection and evapotranspiration will lead to the development of strong-extreme buoyancy (3000-4500+ J/kg MLCAPE) beneath an elevated mixed layer with 8.5-9 C/km midlevel lapse rates. Storms that form in SD are then expected to congeal into a cluster or two that will subsequently spread east-southeastward along the more northwest-southeast oriented baroclinic zone now noted in visible imagery and surface observations from southwest MN into northern IA. The thermodynamic environment will favor both intense updrafts and downdrafts, while deep-layer vertical shear will be sufficient for an organized/bowing MCS. Thus, there will be the potential for swaths of significant-severe outflow (75-90 mph), as well as isolated large hail and a few tornadoes (either with initially discrete supercells or with embedded circulations with bowing segments). ...Central MT this afternoon through early tonight... An embedded speed max will crest the ridge and move from ID to southwest MT this afternoon/evening. Residual boundary-layer dewpoints in the mid-upper 50s in the post-frontal environment, along with surface heating and the north edge of the steeper midlevel lapse rates will favor scattered thunderstorm development by early-mid afternoon (near and just northeast of the higher terrain southwest into central MT). MLCAPE of 1500-2000 J/kg, effective bulk shear in excess of 40 kt and seasonably cool midlevel temperatures suggest the potential for initial supercells with large hail (1-2.5 inches in diameter), and also the potential for upscale growth into a cluster with the attendant threat for wind damage. ..Thompson/Thornton.. 07/28/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Jul 28 2025 Valid 281630Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM EASTERN SOUTH DAKOTA ACROSS SOUTHERN MINNESOTA AND NORTHERN IOWA... ...SUMMARY... Severe storm clusters are expected to form this afternoon in South Dakota and then spread southeastward into Minnesota and Iowa through tonight. Swaths of damaging winds, potentially 75-90 mph, a few tornadoes and isolated large hail will all be possible. ...Dakotas to MN/IA through tonight... Around the northern periphery of a midlevel high covering the southern Plains and Southeast, a series of embedded speed maxima will progress from MT across the Dakotas to MN through early Tuesday. Elevated convection is ongoing in association with two such speed maxima - one over ND and another moving eastward over eastern MT. At the surface, a lee cyclone is present near the SD/NE border, and a baroclinic zone arcs into northeast SD and then southeastward across southwest MN into northern IA. A prior outflow boundary (from dissipated overnight convection) will become more diffuse with time as a result of strong surface heating across IA/NE/SD within the old cold pool. The elevated convection across southern ND, and moving from MT into southwest ND, could persist in the post-frontal environment with weak warm advection atop the frontal surface. Steep midlevel lapse rates and 40-50 kt midlevel flow suggests a continued threat for occasional severe outflow gusts and isolated large hail. The more substantial severe-storm threat is expected to evolve farther southeast by mid-late afternoon along the baroclinic zone in SD, to the northeast of the lee cyclone. Strong surface heating, continued moisture advection and evapotranspiration will lead to the development of strong-extreme buoyancy (3000-4500+ J/kg MLCAPE) beneath an elevated mixed layer with 8.5-9 C/km midlevel lapse rates. Storms that form in SD are then expected to congeal into a cluster or two that will subsequently spread east-southeastward along the more northwest-southeast oriented baroclinic zone now noted in visible imagery and surface observations from southwest MN into northern IA. The thermodynamic environment will favor both intense updrafts and downdrafts, while deep-layer vertical shear will be sufficient for an organized/bowing MCS. Thus, there will be the potential for swaths of significant-severe outflow (75-90 mph), as well as isolated large hail and a few tornadoes (either with initially discrete supercells or with embedded circulations with bowing segments). ...Central MT this afternoon through early tonight... An embedded speed max will crest the ridge and move from ID to southwest MT this afternoon/evening. Residual boundary-layer dewpoints in the mid-upper 50s in the post-frontal environment, along with surface heating and the north edge of the steeper midlevel lapse rates will favor scattered thunderstorm development by early-mid afternoon (near and just northeast of the higher terrain southwest into central MT). MLCAPE of 1500-2000 J/kg, effective bulk shear in excess of 40 kt and seasonably cool midlevel temperatures suggest the potential for initial supercells with large hail (1-2.5 inches in diameter), and also the potential for upscale growth into a cluster with the attendant threat for wind damage. ..Thompson/Thornton.. 07/28/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Jul 28 2025 Valid 281630Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM EASTERN SOUTH DAKOTA ACROSS SOUTHERN MINNESOTA AND NORTHERN IOWA... ...SUMMARY... Severe storm clusters are expected to form this afternoon in South Dakota and then spread southeastward into Minnesota and Iowa through tonight. Swaths of damaging winds, potentially 75-90 mph, a few tornadoes and isolated large hail will all be possible. ...Dakotas to MN/IA through tonight... Around the northern periphery of a midlevel high covering the southern Plains and Southeast, a series of embedded speed maxima will progress from MT across the Dakotas to MN through early Tuesday. Elevated convection is ongoing in association with two such speed maxima - one over ND and another moving eastward over eastern MT. At the surface, a lee cyclone is present near the SD/NE border, and a baroclinic zone arcs into northeast SD and then southeastward across southwest MN into northern IA. A prior outflow boundary (from dissipated overnight convection) will become more diffuse with time as a result of strong surface heating across IA/NE/SD within the old cold pool. The elevated convection across southern ND, and moving from MT into southwest ND, could persist in the post-frontal environment with weak warm advection atop the frontal surface. Steep midlevel lapse rates and 40-50 kt midlevel flow suggests a continued threat for occasional severe outflow gusts and isolated large hail. The more substantial severe-storm threat is expected to evolve farther southeast by mid-late afternoon along the baroclinic zone in SD, to the northeast of the lee cyclone. Strong surface heating, continued moisture advection and evapotranspiration will lead to the development of strong-extreme buoyancy (3000-4500+ J/kg MLCAPE) beneath an elevated mixed layer with 8.5-9 C/km midlevel lapse rates. Storms that form in SD are then expected to congeal into a cluster or two that will subsequently spread east-southeastward along the more northwest-southeast oriented baroclinic zone now noted in visible imagery and surface observations from southwest MN into northern IA. The thermodynamic environment will favor both intense updrafts and downdrafts, while deep-layer vertical shear will be sufficient for an organized/bowing MCS. Thus, there will be the potential for swaths of significant-severe outflow (75-90 mph), as well as isolated large hail and a few tornadoes (either with initially discrete supercells or with embedded circulations with bowing segments). ...Central MT this afternoon through early tonight... An embedded speed max will crest the ridge and move from ID to southwest MT this afternoon/evening. Residual boundary-layer dewpoints in the mid-upper 50s in the post-frontal environment, along with surface heating and the north edge of the steeper midlevel lapse rates will favor scattered thunderstorm development by early-mid afternoon (near and just northeast of the higher terrain southwest into central MT). MLCAPE of 1500-2000 J/kg, effective bulk shear in excess of 40 kt and seasonably cool midlevel temperatures suggest the potential for initial supercells with large hail (1-2.5 inches in diameter), and also the potential for upscale growth into a cluster with the attendant threat for wind damage. ..Thompson/Thornton.. 07/28/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Jul 28 2025 Valid 281630Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM EASTERN SOUTH DAKOTA ACROSS SOUTHERN MINNESOTA AND NORTHERN IOWA... ...SUMMARY... Severe storm clusters are expected to form this afternoon in South Dakota and then spread southeastward into Minnesota and Iowa through tonight. Swaths of damaging winds, potentially 75-90 mph, a few tornadoes and isolated large hail will all be possible. ...Dakotas to MN/IA through tonight... Around the northern periphery of a midlevel high covering the southern Plains and Southeast, a series of embedded speed maxima will progress from MT across the Dakotas to MN through early Tuesday. Elevated convection is ongoing in association with two such speed maxima - one over ND and another moving eastward over eastern MT. At the surface, a lee cyclone is present near the SD/NE border, and a baroclinic zone arcs into northeast SD and then southeastward across southwest MN into northern IA. A prior outflow boundary (from dissipated overnight convection) will become more diffuse with time as a result of strong surface heating across IA/NE/SD within the old cold pool. The elevated convection across southern ND, and moving from MT into southwest ND, could persist in the post-frontal environment with weak warm advection atop the frontal surface. Steep midlevel lapse rates and 40-50 kt midlevel flow suggests a continued threat for occasional severe outflow gusts and isolated large hail. The more substantial severe-storm threat is expected to evolve farther southeast by mid-late afternoon along the baroclinic zone in SD, to the northeast of the lee cyclone. Strong surface heating, continued moisture advection and evapotranspiration will lead to the development of strong-extreme buoyancy (3000-4500+ J/kg MLCAPE) beneath an elevated mixed layer with 8.5-9 C/km midlevel lapse rates. Storms that form in SD are then expected to congeal into a cluster or two that will subsequently spread east-southeastward along the more northwest-southeast oriented baroclinic zone now noted in visible imagery and surface observations from southwest MN into northern IA. The thermodynamic environment will favor both intense updrafts and downdrafts, while deep-layer vertical shear will be sufficient for an organized/bowing MCS. Thus, there will be the potential for swaths of significant-severe outflow (75-90 mph), as well as isolated large hail and a few tornadoes (either with initially discrete supercells or with embedded circulations with bowing segments). ...Central MT this afternoon through early tonight... An embedded speed max will crest the ridge and move from ID to southwest MT this afternoon/evening. Residual boundary-layer dewpoints in the mid-upper 50s in the post-frontal environment, along with surface heating and the north edge of the steeper midlevel lapse rates will favor scattered thunderstorm development by early-mid afternoon (near and just northeast of the higher terrain southwest into central MT). MLCAPE of 1500-2000 J/kg, effective bulk shear in excess of 40 kt and seasonably cool midlevel temperatures suggest the potential for initial supercells with large hail (1-2.5 inches in diameter), and also the potential for upscale growth into a cluster with the attendant threat for wind damage. ..Thompson/Thornton.. 07/28/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Jul 28 2025 Valid 281630Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM EASTERN SOUTH DAKOTA ACROSS SOUTHERN MINNESOTA AND NORTHERN IOWA... ...SUMMARY... Severe storm clusters are expected to form this afternoon in South Dakota and then spread southeastward into Minnesota and Iowa through tonight. Swaths of damaging winds, potentially 75-90 mph, a few tornadoes and isolated large hail will all be possible. ...Dakotas to MN/IA through tonight... Around the northern periphery of a midlevel high covering the southern Plains and Southeast, a series of embedded speed maxima will progress from MT across the Dakotas to MN through early Tuesday. Elevated convection is ongoing in association with two such speed maxima - one over ND and another moving eastward over eastern MT. At the surface, a lee cyclone is present near the SD/NE border, and a baroclinic zone arcs into northeast SD and then southeastward across southwest MN into northern IA. A prior outflow boundary (from dissipated overnight convection) will become more diffuse with time as a result of strong surface heating across IA/NE/SD within the old cold pool. The elevated convection across southern ND, and moving from MT into southwest ND, could persist in the post-frontal environment with weak warm advection atop the frontal surface. Steep midlevel lapse rates and 40-50 kt midlevel flow suggests a continued threat for occasional severe outflow gusts and isolated large hail. The more substantial severe-storm threat is expected to evolve farther southeast by mid-late afternoon along the baroclinic zone in SD, to the northeast of the lee cyclone. Strong surface heating, continued moisture advection and evapotranspiration will lead to the development of strong-extreme buoyancy (3000-4500+ J/kg MLCAPE) beneath an elevated mixed layer with 8.5-9 C/km midlevel lapse rates. Storms that form in SD are then expected to congeal into a cluster or two that will subsequently spread east-southeastward along the more northwest-southeast oriented baroclinic zone now noted in visible imagery and surface observations from southwest MN into northern IA. The thermodynamic environment will favor both intense updrafts and downdrafts, while deep-layer vertical shear will be sufficient for an organized/bowing MCS. Thus, there will be the potential for swaths of significant-severe outflow (75-90 mph), as well as isolated large hail and a few tornadoes (either with initially discrete supercells or with embedded circulations with bowing segments). ...Central MT this afternoon through early tonight... An embedded speed max will crest the ridge and move from ID to southwest MT this afternoon/evening. Residual boundary-layer dewpoints in the mid-upper 50s in the post-frontal environment, along with surface heating and the north edge of the steeper midlevel lapse rates will favor scattered thunderstorm development by early-mid afternoon (near and just northeast of the higher terrain southwest into central MT). MLCAPE of 1500-2000 J/kg, effective bulk shear in excess of 40 kt and seasonably cool midlevel temperatures suggest the potential for initial supercells with large hail (1-2.5 inches in diameter), and also the potential for upscale growth into a cluster with the attendant threat for wind damage. ..Thompson/Thornton.. 07/28/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Jul 28 2025 Valid 281630Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM EASTERN SOUTH DAKOTA ACROSS SOUTHERN MINNESOTA AND NORTHERN IOWA... ...SUMMARY... Severe storm clusters are expected to form this afternoon in South Dakota and then spread southeastward into Minnesota and Iowa through tonight. Swaths of damaging winds, potentially 75-90 mph, a few tornadoes and isolated large hail will all be possible. ...Dakotas to MN/IA through tonight... Around the northern periphery of a midlevel high covering the southern Plains and Southeast, a series of embedded speed maxima will progress from MT across the Dakotas to MN through early Tuesday. Elevated convection is ongoing in association with two such speed maxima - one over ND and another moving eastward over eastern MT. At the surface, a lee cyclone is present near the SD/NE border, and a baroclinic zone arcs into northeast SD and then southeastward across southwest MN into northern IA. A prior outflow boundary (from dissipated overnight convection) will become more diffuse with time as a result of strong surface heating across IA/NE/SD within the old cold pool. The elevated convection across southern ND, and moving from MT into southwest ND, could persist in the post-frontal environment with weak warm advection atop the frontal surface. Steep midlevel lapse rates and 40-50 kt midlevel flow suggests a continued threat for occasional severe outflow gusts and isolated large hail. The more substantial severe-storm threat is expected to evolve farther southeast by mid-late afternoon along the baroclinic zone in SD, to the northeast of the lee cyclone. Strong surface heating, continued moisture advection and evapotranspiration will lead to the development of strong-extreme buoyancy (3000-4500+ J/kg MLCAPE) beneath an elevated mixed layer with 8.5-9 C/km midlevel lapse rates. Storms that form in SD are then expected to congeal into a cluster or two that will subsequently spread east-southeastward along the more northwest-southeast oriented baroclinic zone now noted in visible imagery and surface observations from southwest MN into northern IA. The thermodynamic environment will favor both intense updrafts and downdrafts, while deep-layer vertical shear will be sufficient for an organized/bowing MCS. Thus, there will be the potential for swaths of significant-severe outflow (75-90 mph), as well as isolated large hail and a few tornadoes (either with initially discrete supercells or with embedded circulations with bowing segments). ...Central MT this afternoon through early tonight... An embedded speed max will crest the ridge and move from ID to southwest MT this afternoon/evening. Residual boundary-layer dewpoints in the mid-upper 50s in the post-frontal environment, along with surface heating and the north edge of the steeper midlevel lapse rates will favor scattered thunderstorm development by early-mid afternoon (near and just northeast of the higher terrain southwest into central MT). MLCAPE of 1500-2000 J/kg, effective bulk shear in excess of 40 kt and seasonably cool midlevel temperatures suggest the potential for initial supercells with large hail (1-2.5 inches in diameter), and also the potential for upscale growth into a cluster with the attendant threat for wind damage. ..Thompson/Thornton.. 07/28/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Jul 28 2025 Valid 281630Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM EASTERN SOUTH DAKOTA ACROSS SOUTHERN MINNESOTA AND NORTHERN IOWA... ...SUMMARY... Severe storm clusters are expected to form this afternoon in South Dakota and then spread southeastward into Minnesota and Iowa through tonight. Swaths of damaging winds, potentially 75-90 mph, a few tornadoes and isolated large hail will all be possible. ...Dakotas to MN/IA through tonight... Around the northern periphery of a midlevel high covering the southern Plains and Southeast, a series of embedded speed maxima will progress from MT across the Dakotas to MN through early Tuesday. Elevated convection is ongoing in association with two such speed maxima - one over ND and another moving eastward over eastern MT. At the surface, a lee cyclone is present near the SD/NE border, and a baroclinic zone arcs into northeast SD and then southeastward across southwest MN into northern IA. A prior outflow boundary (from dissipated overnight convection) will become more diffuse with time as a result of strong surface heating across IA/NE/SD within the old cold pool. The elevated convection across southern ND, and moving from MT into southwest ND, could persist in the post-frontal environment with weak warm advection atop the frontal surface. Steep midlevel lapse rates and 40-50 kt midlevel flow suggests a continued threat for occasional severe outflow gusts and isolated large hail. The more substantial severe-storm threat is expected to evolve farther southeast by mid-late afternoon along the baroclinic zone in SD, to the northeast of the lee cyclone. Strong surface heating, continued moisture advection and evapotranspiration will lead to the development of strong-extreme buoyancy (3000-4500+ J/kg MLCAPE) beneath an elevated mixed layer with 8.5-9 C/km midlevel lapse rates. Storms that form in SD are then expected to congeal into a cluster or two that will subsequently spread east-southeastward along the more northwest-southeast oriented baroclinic zone now noted in visible imagery and surface observations from southwest MN into northern IA. The thermodynamic environment will favor both intense updrafts and downdrafts, while deep-layer vertical shear will be sufficient for an organized/bowing MCS. Thus, there will be the potential for swaths of significant-severe outflow (75-90 mph), as well as isolated large hail and a few tornadoes (either with initially discrete supercells or with embedded circulations with bowing segments). ...Central MT this afternoon through early tonight... An embedded speed max will crest the ridge and move from ID to southwest MT this afternoon/evening. Residual boundary-layer dewpoints in the mid-upper 50s in the post-frontal environment, along with surface heating and the north edge of the steeper midlevel lapse rates will favor scattered thunderstorm development by early-mid afternoon (near and just northeast of the higher terrain southwest into central MT). MLCAPE of 1500-2000 J/kg, effective bulk shear in excess of 40 kt and seasonably cool midlevel temperatures suggest the potential for initial supercells with large hail (1-2.5 inches in diameter), and also the potential for upscale growth into a cluster with the attendant threat for wind damage. ..Thompson/Thornton.. 07/28/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Jul 28 2025 Valid 281630Z - 291200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON INTO TONIGHT FROM EASTERN SOUTH DAKOTA ACROSS SOUTHERN MINNESOTA AND NORTHERN IOWA... ...SUMMARY... Severe storm clusters are expected to form this afternoon in South Dakota and then spread southeastward into Minnesota and Iowa through tonight. Swaths of damaging winds, potentially 75-90 mph, a few tornadoes and isolated large hail will all be possible. ...Dakotas to MN/IA through tonight... Around the northern periphery of a midlevel high covering the southern Plains and Southeast, a series of embedded speed maxima will progress from MT across the Dakotas to MN through early Tuesday. Elevated convection is ongoing in association with two such speed maxima - one over ND and another moving eastward over eastern MT. At the surface, a lee cyclone is present near the SD/NE border, and a baroclinic zone arcs into northeast SD and then southeastward across southwest MN into northern IA. A prior outflow boundary (from dissipated overnight convection) will become more diffuse with time as a result of strong surface heating across IA/NE/SD within the old cold pool. The elevated convection across southern ND, and moving from MT into southwest ND, could persist in the post-frontal environment with weak warm advection atop the frontal surface. Steep midlevel lapse rates and 40-50 kt midlevel flow suggests a continued threat for occasional severe outflow gusts and isolated large hail. The more substantial severe-storm threat is expected to evolve farther southeast by mid-late afternoon along the baroclinic zone in SD, to the northeast of the lee cyclone. Strong surface heating, continued moisture advection and evapotranspiration will lead to the development of strong-extreme buoyancy (3000-4500+ J/kg MLCAPE) beneath an elevated mixed layer with 8.5-9 C/km midlevel lapse rates. Storms that form in SD are then expected to congeal into a cluster or two that will subsequently spread east-southeastward along the more northwest-southeast oriented baroclinic zone now noted in visible imagery and surface observations from southwest MN into northern IA. The thermodynamic environment will favor both intense updrafts and downdrafts, while deep-layer vertical shear will be sufficient for an organized/bowing MCS. Thus, there will be the potential for swaths of significant-severe outflow (75-90 mph), as well as isolated large hail and a few tornadoes (either with initially discrete supercells or with embedded circulations with bowing segments). ...Central MT this afternoon through early tonight... An embedded speed max will crest the ridge and move from ID to southwest MT this afternoon/evening. Residual boundary-layer dewpoints in the mid-upper 50s in the post-frontal environment, along with surface heating and the north edge of the steeper midlevel lapse rates will favor scattered thunderstorm development by early-mid afternoon (near and just northeast of the higher terrain southwest into central MT). MLCAPE of 1500-2000 J/kg, effective bulk shear in excess of 40 kt and seasonably cool midlevel temperatures suggest the potential for initial supercells with large hail (1-2.5 inches in diameter), and also the potential for upscale growth into a cluster with the attendant threat for wind damage. ..Thompson/Thornton.. 07/28/2025 Read more