Severe Storms

WW 0446 Status Updates
STATUS REPORT ON WW 446 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 WSW BKX TO 35 N ATY TO 40 SSW TVF. ..LEITMAN..06/20/25 ATTN...WFO...FGF...MPX...ABR...FSD... STATUS REPORT FOR WS 446 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS MNC005-009-011-023-027-033-041-051-063-067-073-081-083-093-097- 101-105-107-111-117-121-127-129-133-145-149-151-153-155-159-167- 173-200740- MN . MINNESOTA COUNTIES INCLUDED ARE BECKER BENTON BIG STONE CHIPPEWA CLAY COTTONWOOD DOUGLAS GRANT JACKSON KANDIYOHI LAC QUI PARLE LINCOLN LYON MEEKER MORRISON MURRAY NOBLES NORMAN OTTER TAIL PIPESTONE POPE REDWOOD RENVILLE ROCK STEARNS STEVENS SWIFT TODD TRAVERSE WADENA WILKIN YELLOW MEDICINE SDC011-029-039-051-057-109-200740- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE Read more

WW 446 SEVERE TSTM MN ND SD 200210Z - 200900Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 446 NWS Storm Prediction Center Norman OK 910 PM CDT Thu Jun 19 2025 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Western into Central Minnesota Southeast North Dakota Northern into Northeast South Dakota * Effective this Thursday night and Friday morning from 910 PM until 400 AM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2.5 inches in diameter possible Scattered damaging wind gusts to 70 mph possible SUMMARY...Isolated severe thunderstorms this evening will pose a risk for large to very large hail and severe gusts. Thunderstorms are forecast to increase in coverage late this evening into the overnight. The risks for hail and wind will likely continue as the expected thunderstorm activity gradually shifts from west to east across the Watch area. The severe thunderstorm watch area is approximately along and 100 statute miles north and south of a line from 55 miles southwest of Jamestown ND to 65 miles east southeast of Alexandria MN. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU6). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && OTHER WATCH INFORMATION...CONTINUE...WW 443...WW 444...WW 445... AVIATION...A few severe thunderstorms with hail surface and aloft to 2.5 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 30025. ...Smith Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0132 AM CDT Fri Jun 20 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE FOUR CORNERS AND GREAT BASIN... ...Synopsis... Widespread critical fire weather conditions are expected today across parts of the Greater Four Corners region and the Great Basin. Early-morning water vapor imagery shows a dominant upper ridge over the central CONUS with shortwave troughing over the western Great Basin and northeastern Pacific. The Great Basin shortwave is forecast to move into the northern High Plains through the afternoon, which will facilitate surface low development across eastern WY by late afternoon. Strengthening low-level winds in response to the deepening low will promote a widespread swath of 20-30 mph winds within a very dry air mass and across a region with receptive fuels. ...Four Corners into the High Plains... The axis of the mid-level jet associated with the leading shortwave is forecast to reside from southeast UT into southern WY by peak heating. This will maximize the potential for 20+ mph winds at the surface, and will likely support wind gusts between 30-45 mph. RH values in the single digits to low teens coupled with antecedent dry fuels (active fires were recently noted across southern UT in GOES IR imagery) will support widespread and prolonged critical conditions with periods of extremely critical wind speeds possible - especially across south-central WY. Elevated to critical fire weather conditions will likely extend well to the northeast into the central High Plains, and possibly as far east and western South Dakota behind an eastward surging dry line. However, fuel conditions generally improve with eastward extent due to recent rainfall. Fire risk highlights have been expanded northeast to account for the strong wind/RH signal, but Critical highlights were focused across areas with dry, receptive fuels. ...Nevada into adjacent portions of Idaho and Utah... Southwesterly flow over the southern to central Sierra Nevada will induce strong downslope flow into western and central NV, spreading into southeast ID and western UT by late afternoon. Guidance continues to show a strong signal for 20-25 mph winds through much of the afternoon, and single-digit RH values should support widespread critical fire weather conditions. ...Southern California into the San Joaquin Valley... A strong onshore pressure gradient will support increasing downslope winds on the leeward side/eastern slopes of the coastal ranges across southern California this afternoon. Relative humidities values falling into the teens within the downslope regime, coupled with dry grasses, will support a fire weather concern. ..Moore.. 06/20/2025 ...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 0132 AM CDT Fri Jun 20 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE FOUR CORNERS AND GREAT BASIN... ...Synopsis... Widespread critical fire weather conditions are expected today across parts of the Greater Four Corners region and the Great Basin. Early-morning water vapor imagery shows a dominant upper ridge over the central CONUS with shortwave troughing over the western Great Basin and northeastern Pacific. The Great Basin shortwave is forecast to move into the northern High Plains through the afternoon, which will facilitate surface low development across eastern WY by late afternoon. Strengthening low-level winds in response to the deepening low will promote a widespread swath of 20-30 mph winds within a very dry air mass and across a region with receptive fuels. ...Four Corners into the High Plains... The axis of the mid-level jet associated with the leading shortwave is forecast to reside from southeast UT into southern WY by peak heating. This will maximize the potential for 20+ mph winds at the surface, and will likely support wind gusts between 30-45 mph. RH values in the single digits to low teens coupled with antecedent dry fuels (active fires were recently noted across southern UT in GOES IR imagery) will support widespread and prolonged critical conditions with periods of extremely critical wind speeds possible - especially across south-central WY. Elevated to critical fire weather conditions will likely extend well to the northeast into the central High Plains, and possibly as far east and western South Dakota behind an eastward surging dry line. However, fuel conditions generally improve with eastward extent due to recent rainfall. Fire risk highlights have been expanded northeast to account for the strong wind/RH signal, but Critical highlights were focused across areas with dry, receptive fuels. ...Nevada into adjacent portions of Idaho and Utah... Southwesterly flow over the southern to central Sierra Nevada will induce strong downslope flow into western and central NV, spreading into southeast ID and western UT by late afternoon. Guidance continues to show a strong signal for 20-25 mph winds through much of the afternoon, and single-digit RH values should support widespread critical fire weather conditions. ...Southern California into the San Joaquin Valley... A strong onshore pressure gradient will support increasing downslope winds on the leeward side/eastern slopes of the coastal ranges across southern California this afternoon. Relative humidities values falling into the teens within the downslope regime, coupled with dry grasses, will support a fire weather concern. ..Moore.. 06/20/2025 ...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 0132 AM CDT Fri Jun 20 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE FOUR CORNERS AND GREAT BASIN... ...Synopsis... Widespread critical fire weather conditions are expected today across parts of the Greater Four Corners region and the Great Basin. Early-morning water vapor imagery shows a dominant upper ridge over the central CONUS with shortwave troughing over the western Great Basin and northeastern Pacific. The Great Basin shortwave is forecast to move into the northern High Plains through the afternoon, which will facilitate surface low development across eastern WY by late afternoon. Strengthening low-level winds in response to the deepening low will promote a widespread swath of 20-30 mph winds within a very dry air mass and across a region with receptive fuels. ...Four Corners into the High Plains... The axis of the mid-level jet associated with the leading shortwave is forecast to reside from southeast UT into southern WY by peak heating. This will maximize the potential for 20+ mph winds at the surface, and will likely support wind gusts between 30-45 mph. RH values in the single digits to low teens coupled with antecedent dry fuels (active fires were recently noted across southern UT in GOES IR imagery) will support widespread and prolonged critical conditions with periods of extremely critical wind speeds possible - especially across south-central WY. Elevated to critical fire weather conditions will likely extend well to the northeast into the central High Plains, and possibly as far east and western South Dakota behind an eastward surging dry line. However, fuel conditions generally improve with eastward extent due to recent rainfall. Fire risk highlights have been expanded northeast to account for the strong wind/RH signal, but Critical highlights were focused across areas with dry, receptive fuels. ...Nevada into adjacent portions of Idaho and Utah... Southwesterly flow over the southern to central Sierra Nevada will induce strong downslope flow into western and central NV, spreading into southeast ID and western UT by late afternoon. Guidance continues to show a strong signal for 20-25 mph winds through much of the afternoon, and single-digit RH values should support widespread critical fire weather conditions. ...Southern California into the San Joaquin Valley... A strong onshore pressure gradient will support increasing downslope winds on the leeward side/eastern slopes of the coastal ranges across southern California this afternoon. Relative humidities values falling into the teens within the downslope regime, coupled with dry grasses, will support a fire weather concern. ..Moore.. 06/20/2025 ...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 0132 AM CDT Fri Jun 20 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE FOUR CORNERS AND GREAT BASIN... ...Synopsis... Widespread critical fire weather conditions are expected today across parts of the Greater Four Corners region and the Great Basin. Early-morning water vapor imagery shows a dominant upper ridge over the central CONUS with shortwave troughing over the western Great Basin and northeastern Pacific. The Great Basin shortwave is forecast to move into the northern High Plains through the afternoon, which will facilitate surface low development across eastern WY by late afternoon. Strengthening low-level winds in response to the deepening low will promote a widespread swath of 20-30 mph winds within a very dry air mass and across a region with receptive fuels. ...Four Corners into the High Plains... The axis of the mid-level jet associated with the leading shortwave is forecast to reside from southeast UT into southern WY by peak heating. This will maximize the potential for 20+ mph winds at the surface, and will likely support wind gusts between 30-45 mph. RH values in the single digits to low teens coupled with antecedent dry fuels (active fires were recently noted across southern UT in GOES IR imagery) will support widespread and prolonged critical conditions with periods of extremely critical wind speeds possible - especially across south-central WY. Elevated to critical fire weather conditions will likely extend well to the northeast into the central High Plains, and possibly as far east and western South Dakota behind an eastward surging dry line. However, fuel conditions generally improve with eastward extent due to recent rainfall. Fire risk highlights have been expanded northeast to account for the strong wind/RH signal, but Critical highlights were focused across areas with dry, receptive fuels. ...Nevada into adjacent portions of Idaho and Utah... Southwesterly flow over the southern to central Sierra Nevada will induce strong downslope flow into western and central NV, spreading into southeast ID and western UT by late afternoon. Guidance continues to show a strong signal for 20-25 mph winds through much of the afternoon, and single-digit RH values should support widespread critical fire weather conditions. ...Southern California into the San Joaquin Valley... A strong onshore pressure gradient will support increasing downslope winds on the leeward side/eastern slopes of the coastal ranges across southern California this afternoon. Relative humidities values falling into the teens within the downslope regime, coupled with dry grasses, will support a fire weather concern. ..Moore.. 06/20/2025 ...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 0132 AM CDT Fri Jun 20 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE FOUR CORNERS AND GREAT BASIN... ...Synopsis... Widespread critical fire weather conditions are expected today across parts of the Greater Four Corners region and the Great Basin. Early-morning water vapor imagery shows a dominant upper ridge over the central CONUS with shortwave troughing over the western Great Basin and northeastern Pacific. The Great Basin shortwave is forecast to move into the northern High Plains through the afternoon, which will facilitate surface low development across eastern WY by late afternoon. Strengthening low-level winds in response to the deepening low will promote a widespread swath of 20-30 mph winds within a very dry air mass and across a region with receptive fuels. ...Four Corners into the High Plains... The axis of the mid-level jet associated with the leading shortwave is forecast to reside from southeast UT into southern WY by peak heating. This will maximize the potential for 20+ mph winds at the surface, and will likely support wind gusts between 30-45 mph. RH values in the single digits to low teens coupled with antecedent dry fuels (active fires were recently noted across southern UT in GOES IR imagery) will support widespread and prolonged critical conditions with periods of extremely critical wind speeds possible - especially across south-central WY. Elevated to critical fire weather conditions will likely extend well to the northeast into the central High Plains, and possibly as far east and western South Dakota behind an eastward surging dry line. However, fuel conditions generally improve with eastward extent due to recent rainfall. Fire risk highlights have been expanded northeast to account for the strong wind/RH signal, but Critical highlights were focused across areas with dry, receptive fuels. ...Nevada into adjacent portions of Idaho and Utah... Southwesterly flow over the southern to central Sierra Nevada will induce strong downslope flow into western and central NV, spreading into southeast ID and western UT by late afternoon. Guidance continues to show a strong signal for 20-25 mph winds through much of the afternoon, and single-digit RH values should support widespread critical fire weather conditions. ...Southern California into the San Joaquin Valley... A strong onshore pressure gradient will support increasing downslope winds on the leeward side/eastern slopes of the coastal ranges across southern California this afternoon. Relative humidities values falling into the teens within the downslope regime, coupled with dry grasses, will support a fire weather concern. ..Moore.. 06/20/2025 ...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 0132 AM CDT Fri Jun 20 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE FOUR CORNERS AND GREAT BASIN... ...Synopsis... Widespread critical fire weather conditions are expected today across parts of the Greater Four Corners region and the Great Basin. Early-morning water vapor imagery shows a dominant upper ridge over the central CONUS with shortwave troughing over the western Great Basin and northeastern Pacific. The Great Basin shortwave is forecast to move into the northern High Plains through the afternoon, which will facilitate surface low development across eastern WY by late afternoon. Strengthening low-level winds in response to the deepening low will promote a widespread swath of 20-30 mph winds within a very dry air mass and across a region with receptive fuels. ...Four Corners into the High Plains... The axis of the mid-level jet associated with the leading shortwave is forecast to reside from southeast UT into southern WY by peak heating. This will maximize the potential for 20+ mph winds at the surface, and will likely support wind gusts between 30-45 mph. RH values in the single digits to low teens coupled with antecedent dry fuels (active fires were recently noted across southern UT in GOES IR imagery) will support widespread and prolonged critical conditions with periods of extremely critical wind speeds possible - especially across south-central WY. Elevated to critical fire weather conditions will likely extend well to the northeast into the central High Plains, and possibly as far east and western South Dakota behind an eastward surging dry line. However, fuel conditions generally improve with eastward extent due to recent rainfall. Fire risk highlights have been expanded northeast to account for the strong wind/RH signal, but Critical highlights were focused across areas with dry, receptive fuels. ...Nevada into adjacent portions of Idaho and Utah... Southwesterly flow over the southern to central Sierra Nevada will induce strong downslope flow into western and central NV, spreading into southeast ID and western UT by late afternoon. Guidance continues to show a strong signal for 20-25 mph winds through much of the afternoon, and single-digit RH values should support widespread critical fire weather conditions. ...Southern California into the San Joaquin Valley... A strong onshore pressure gradient will support increasing downslope winds on the leeward side/eastern slopes of the coastal ranges across southern California this afternoon. Relative humidities values falling into the teens within the downslope regime, coupled with dry grasses, will support a fire weather concern. ..Moore.. 06/20/2025 ...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 0132 AM CDT Fri Jun 20 2025 Valid 201200Z - 211200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE FOUR CORNERS AND GREAT BASIN... ...Synopsis... Widespread critical fire weather conditions are expected today across parts of the Greater Four Corners region and the Great Basin. Early-morning water vapor imagery shows a dominant upper ridge over the central CONUS with shortwave troughing over the western Great Basin and northeastern Pacific. The Great Basin shortwave is forecast to move into the northern High Plains through the afternoon, which will facilitate surface low development across eastern WY by late afternoon. Strengthening low-level winds in response to the deepening low will promote a widespread swath of 20-30 mph winds within a very dry air mass and across a region with receptive fuels. ...Four Corners into the High Plains... The axis of the mid-level jet associated with the leading shortwave is forecast to reside from southeast UT into southern WY by peak heating. This will maximize the potential for 20+ mph winds at the surface, and will likely support wind gusts between 30-45 mph. RH values in the single digits to low teens coupled with antecedent dry fuels (active fires were recently noted across southern UT in GOES IR imagery) will support widespread and prolonged critical conditions with periods of extremely critical wind speeds possible - especially across south-central WY. Elevated to critical fire weather conditions will likely extend well to the northeast into the central High Plains, and possibly as far east and western South Dakota behind an eastward surging dry line. However, fuel conditions generally improve with eastward extent due to recent rainfall. Fire risk highlights have been expanded northeast to account for the strong wind/RH signal, but Critical highlights were focused across areas with dry, receptive fuels. ...Nevada into adjacent portions of Idaho and Utah... Southwesterly flow over the southern to central Sierra Nevada will induce strong downslope flow into western and central NV, spreading into southeast ID and western UT by late afternoon. Guidance continues to show a strong signal for 20-25 mph winds through much of the afternoon, and single-digit RH values should support widespread critical fire weather conditions. ...Southern California into the San Joaquin Valley... A strong onshore pressure gradient will support increasing downslope winds on the leeward side/eastern slopes of the coastal ranges across southern California this afternoon. Relative humidities values falling into the teens within the downslope regime, coupled with dry grasses, will support a fire weather concern. ..Moore.. 06/20/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0104 AM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NY AND NORTHERN PA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... A deep mid/upper-level trough will move gradually eastward across the western CONUS on Saturday, as an embedded shortwave trough moves from parts ID/MT into the Canadian Prairies. A surface low initially over the northern Plains is forecast to move northeast through the day, with a secondary surface low expected to develop along a cold front across the central High Plains during the evening. Downstream, a mid/upper-level shortwave trough (possibly augmented by D1/Friday MCS development) is generally forecast to move from the northern Great Lakes toward New England. ...Great Lakes into the Northeast... An MCS will likely be ongoing Saturday morning across parts of the northern Great Lakes, with other areas of elevated convection possible farther south across lower MI. While there is some uncertainty regarding MCS timing, some damaging-wind and hail threat would accompany this system and any other robust morning convection before spreading into Ontario. The convectively augmented shortwave trough associated with the potential MCS may continue to impinge upon the northeast periphery of an expanding instability reservoir. Even if the morning MCS weakens or stays in Canada, strong to potentially severe storms may spread southward out of Ontario into the lower Great Lakes region, and/or develop within a low-level warm advection regime. Damaging winds may be the most common hazard, though low-level shear/SRH may become sufficient for a localized tornado threat as well. Convection may continue into late Saturday night with at least an isolated severe threat. Farther west, there is some potential for isolated storm development during the afternoon/evening across the northern Great Lakes vicinity, within a conditionally favorable environment. However, with large-scale ascent expected to remain rather nebulous in the wake of the departing MCS and shortwave trough, confidence is currently low regarding this scenario. ...Northern Plains into the Upper Midwest... While there is some lingering uncertainty regarding the influence of D1/Friday convection, strong to extreme buoyancy is likely to again develop across parts of the northern Plains and Upper Midwest, along and east of the cold front. However, very warm temperatures aloft and generally weak large-scale ascent may tend to suppress storm development across much of the strongly unstable warm sector. Strong heating could support isolated development across parts of NE/SD/eastern ND into northern MN near the surface low and front, which would conditionally pose a severe threat given the favorable parameter space. Farther northwest, guidance continues to vary regarding the magnitude of instability from eastern MT/northern WY into the western Dakotas. Strong morning convection will be possible across eastern MT, and some redevelopment may occur during the afternoon/evening, depending on the extent to which the departing MT shortwave trough can impinge upon favorable instability. A supercell or two will be possible, with a localized threat for all severe hazards. ..Dean.. 06/20/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0104 AM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NY AND NORTHERN PA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... A deep mid/upper-level trough will move gradually eastward across the western CONUS on Saturday, as an embedded shortwave trough moves from parts ID/MT into the Canadian Prairies. A surface low initially over the northern Plains is forecast to move northeast through the day, with a secondary surface low expected to develop along a cold front across the central High Plains during the evening. Downstream, a mid/upper-level shortwave trough (possibly augmented by D1/Friday MCS development) is generally forecast to move from the northern Great Lakes toward New England. ...Great Lakes into the Northeast... An MCS will likely be ongoing Saturday morning across parts of the northern Great Lakes, with other areas of elevated convection possible farther south across lower MI. While there is some uncertainty regarding MCS timing, some damaging-wind and hail threat would accompany this system and any other robust morning convection before spreading into Ontario. The convectively augmented shortwave trough associated with the potential MCS may continue to impinge upon the northeast periphery of an expanding instability reservoir. Even if the morning MCS weakens or stays in Canada, strong to potentially severe storms may spread southward out of Ontario into the lower Great Lakes region, and/or develop within a low-level warm advection regime. Damaging winds may be the most common hazard, though low-level shear/SRH may become sufficient for a localized tornado threat as well. Convection may continue into late Saturday night with at least an isolated severe threat. Farther west, there is some potential for isolated storm development during the afternoon/evening across the northern Great Lakes vicinity, within a conditionally favorable environment. However, with large-scale ascent expected to remain rather nebulous in the wake of the departing MCS and shortwave trough, confidence is currently low regarding this scenario. ...Northern Plains into the Upper Midwest... While there is some lingering uncertainty regarding the influence of D1/Friday convection, strong to extreme buoyancy is likely to again develop across parts of the northern Plains and Upper Midwest, along and east of the cold front. However, very warm temperatures aloft and generally weak large-scale ascent may tend to suppress storm development across much of the strongly unstable warm sector. Strong heating could support isolated development across parts of NE/SD/eastern ND into northern MN near the surface low and front, which would conditionally pose a severe threat given the favorable parameter space. Farther northwest, guidance continues to vary regarding the magnitude of instability from eastern MT/northern WY into the western Dakotas. Strong morning convection will be possible across eastern MT, and some redevelopment may occur during the afternoon/evening, depending on the extent to which the departing MT shortwave trough can impinge upon favorable instability. A supercell or two will be possible, with a localized threat for all severe hazards. ..Dean.. 06/20/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0104 AM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NY AND NORTHERN PA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... A deep mid/upper-level trough will move gradually eastward across the western CONUS on Saturday, as an embedded shortwave trough moves from parts ID/MT into the Canadian Prairies. A surface low initially over the northern Plains is forecast to move northeast through the day, with a secondary surface low expected to develop along a cold front across the central High Plains during the evening. Downstream, a mid/upper-level shortwave trough (possibly augmented by D1/Friday MCS development) is generally forecast to move from the northern Great Lakes toward New England. ...Great Lakes into the Northeast... An MCS will likely be ongoing Saturday morning across parts of the northern Great Lakes, with other areas of elevated convection possible farther south across lower MI. While there is some uncertainty regarding MCS timing, some damaging-wind and hail threat would accompany this system and any other robust morning convection before spreading into Ontario. The convectively augmented shortwave trough associated with the potential MCS may continue to impinge upon the northeast periphery of an expanding instability reservoir. Even if the morning MCS weakens or stays in Canada, strong to potentially severe storms may spread southward out of Ontario into the lower Great Lakes region, and/or develop within a low-level warm advection regime. Damaging winds may be the most common hazard, though low-level shear/SRH may become sufficient for a localized tornado threat as well. Convection may continue into late Saturday night with at least an isolated severe threat. Farther west, there is some potential for isolated storm development during the afternoon/evening across the northern Great Lakes vicinity, within a conditionally favorable environment. However, with large-scale ascent expected to remain rather nebulous in the wake of the departing MCS and shortwave trough, confidence is currently low regarding this scenario. ...Northern Plains into the Upper Midwest... While there is some lingering uncertainty regarding the influence of D1/Friday convection, strong to extreme buoyancy is likely to again develop across parts of the northern Plains and Upper Midwest, along and east of the cold front. However, very warm temperatures aloft and generally weak large-scale ascent may tend to suppress storm development across much of the strongly unstable warm sector. Strong heating could support isolated development across parts of NE/SD/eastern ND into northern MN near the surface low and front, which would conditionally pose a severe threat given the favorable parameter space. Farther northwest, guidance continues to vary regarding the magnitude of instability from eastern MT/northern WY into the western Dakotas. Strong morning convection will be possible across eastern MT, and some redevelopment may occur during the afternoon/evening, depending on the extent to which the departing MT shortwave trough can impinge upon favorable instability. A supercell or two will be possible, with a localized threat for all severe hazards. ..Dean.. 06/20/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0104 AM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NY AND NORTHERN PA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... A deep mid/upper-level trough will move gradually eastward across the western CONUS on Saturday, as an embedded shortwave trough moves from parts ID/MT into the Canadian Prairies. A surface low initially over the northern Plains is forecast to move northeast through the day, with a secondary surface low expected to develop along a cold front across the central High Plains during the evening. Downstream, a mid/upper-level shortwave trough (possibly augmented by D1/Friday MCS development) is generally forecast to move from the northern Great Lakes toward New England. ...Great Lakes into the Northeast... An MCS will likely be ongoing Saturday morning across parts of the northern Great Lakes, with other areas of elevated convection possible farther south across lower MI. While there is some uncertainty regarding MCS timing, some damaging-wind and hail threat would accompany this system and any other robust morning convection before spreading into Ontario. The convectively augmented shortwave trough associated with the potential MCS may continue to impinge upon the northeast periphery of an expanding instability reservoir. Even if the morning MCS weakens or stays in Canada, strong to potentially severe storms may spread southward out of Ontario into the lower Great Lakes region, and/or develop within a low-level warm advection regime. Damaging winds may be the most common hazard, though low-level shear/SRH may become sufficient for a localized tornado threat as well. Convection may continue into late Saturday night with at least an isolated severe threat. Farther west, there is some potential for isolated storm development during the afternoon/evening across the northern Great Lakes vicinity, within a conditionally favorable environment. However, with large-scale ascent expected to remain rather nebulous in the wake of the departing MCS and shortwave trough, confidence is currently low regarding this scenario. ...Northern Plains into the Upper Midwest... While there is some lingering uncertainty regarding the influence of D1/Friday convection, strong to extreme buoyancy is likely to again develop across parts of the northern Plains and Upper Midwest, along and east of the cold front. However, very warm temperatures aloft and generally weak large-scale ascent may tend to suppress storm development across much of the strongly unstable warm sector. Strong heating could support isolated development across parts of NE/SD/eastern ND into northern MN near the surface low and front, which would conditionally pose a severe threat given the favorable parameter space. Farther northwest, guidance continues to vary regarding the magnitude of instability from eastern MT/northern WY into the western Dakotas. Strong morning convection will be possible across eastern MT, and some redevelopment may occur during the afternoon/evening, depending on the extent to which the departing MT shortwave trough can impinge upon favorable instability. A supercell or two will be possible, with a localized threat for all severe hazards. ..Dean.. 06/20/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0104 AM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NY AND NORTHERN PA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... A deep mid/upper-level trough will move gradually eastward across the western CONUS on Saturday, as an embedded shortwave trough moves from parts ID/MT into the Canadian Prairies. A surface low initially over the northern Plains is forecast to move northeast through the day, with a secondary surface low expected to develop along a cold front across the central High Plains during the evening. Downstream, a mid/upper-level shortwave trough (possibly augmented by D1/Friday MCS development) is generally forecast to move from the northern Great Lakes toward New England. ...Great Lakes into the Northeast... An MCS will likely be ongoing Saturday morning across parts of the northern Great Lakes, with other areas of elevated convection possible farther south across lower MI. While there is some uncertainty regarding MCS timing, some damaging-wind and hail threat would accompany this system and any other robust morning convection before spreading into Ontario. The convectively augmented shortwave trough associated with the potential MCS may continue to impinge upon the northeast periphery of an expanding instability reservoir. Even if the morning MCS weakens or stays in Canada, strong to potentially severe storms may spread southward out of Ontario into the lower Great Lakes region, and/or develop within a low-level warm advection regime. Damaging winds may be the most common hazard, though low-level shear/SRH may become sufficient for a localized tornado threat as well. Convection may continue into late Saturday night with at least an isolated severe threat. Farther west, there is some potential for isolated storm development during the afternoon/evening across the northern Great Lakes vicinity, within a conditionally favorable environment. However, with large-scale ascent expected to remain rather nebulous in the wake of the departing MCS and shortwave trough, confidence is currently low regarding this scenario. ...Northern Plains into the Upper Midwest... While there is some lingering uncertainty regarding the influence of D1/Friday convection, strong to extreme buoyancy is likely to again develop across parts of the northern Plains and Upper Midwest, along and east of the cold front. However, very warm temperatures aloft and generally weak large-scale ascent may tend to suppress storm development across much of the strongly unstable warm sector. Strong heating could support isolated development across parts of NE/SD/eastern ND into northern MN near the surface low and front, which would conditionally pose a severe threat given the favorable parameter space. Farther northwest, guidance continues to vary regarding the magnitude of instability from eastern MT/northern WY into the western Dakotas. Strong morning convection will be possible across eastern MT, and some redevelopment may occur during the afternoon/evening, depending on the extent to which the departing MT shortwave trough can impinge upon favorable instability. A supercell or two will be possible, with a localized threat for all severe hazards. ..Dean.. 06/20/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0104 AM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NY AND NORTHERN PA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... A deep mid/upper-level trough will move gradually eastward across the western CONUS on Saturday, as an embedded shortwave trough moves from parts ID/MT into the Canadian Prairies. A surface low initially over the northern Plains is forecast to move northeast through the day, with a secondary surface low expected to develop along a cold front across the central High Plains during the evening. Downstream, a mid/upper-level shortwave trough (possibly augmented by D1/Friday MCS development) is generally forecast to move from the northern Great Lakes toward New England. ...Great Lakes into the Northeast... An MCS will likely be ongoing Saturday morning across parts of the northern Great Lakes, with other areas of elevated convection possible farther south across lower MI. While there is some uncertainty regarding MCS timing, some damaging-wind and hail threat would accompany this system and any other robust morning convection before spreading into Ontario. The convectively augmented shortwave trough associated with the potential MCS may continue to impinge upon the northeast periphery of an expanding instability reservoir. Even if the morning MCS weakens or stays in Canada, strong to potentially severe storms may spread southward out of Ontario into the lower Great Lakes region, and/or develop within a low-level warm advection regime. Damaging winds may be the most common hazard, though low-level shear/SRH may become sufficient for a localized tornado threat as well. Convection may continue into late Saturday night with at least an isolated severe threat. Farther west, there is some potential for isolated storm development during the afternoon/evening across the northern Great Lakes vicinity, within a conditionally favorable environment. However, with large-scale ascent expected to remain rather nebulous in the wake of the departing MCS and shortwave trough, confidence is currently low regarding this scenario. ...Northern Plains into the Upper Midwest... While there is some lingering uncertainty regarding the influence of D1/Friday convection, strong to extreme buoyancy is likely to again develop across parts of the northern Plains and Upper Midwest, along and east of the cold front. However, very warm temperatures aloft and generally weak large-scale ascent may tend to suppress storm development across much of the strongly unstable warm sector. Strong heating could support isolated development across parts of NE/SD/eastern ND into northern MN near the surface low and front, which would conditionally pose a severe threat given the favorable parameter space. Farther northwest, guidance continues to vary regarding the magnitude of instability from eastern MT/northern WY into the western Dakotas. Strong morning convection will be possible across eastern MT, and some redevelopment may occur during the afternoon/evening, depending on the extent to which the departing MT shortwave trough can impinge upon favorable instability. A supercell or two will be possible, with a localized threat for all severe hazards. ..Dean.. 06/20/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0104 AM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NY AND NORTHERN PA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... A deep mid/upper-level trough will move gradually eastward across the western CONUS on Saturday, as an embedded shortwave trough moves from parts ID/MT into the Canadian Prairies. A surface low initially over the northern Plains is forecast to move northeast through the day, with a secondary surface low expected to develop along a cold front across the central High Plains during the evening. Downstream, a mid/upper-level shortwave trough (possibly augmented by D1/Friday MCS development) is generally forecast to move from the northern Great Lakes toward New England. ...Great Lakes into the Northeast... An MCS will likely be ongoing Saturday morning across parts of the northern Great Lakes, with other areas of elevated convection possible farther south across lower MI. While there is some uncertainty regarding MCS timing, some damaging-wind and hail threat would accompany this system and any other robust morning convection before spreading into Ontario. The convectively augmented shortwave trough associated with the potential MCS may continue to impinge upon the northeast periphery of an expanding instability reservoir. Even if the morning MCS weakens or stays in Canada, strong to potentially severe storms may spread southward out of Ontario into the lower Great Lakes region, and/or develop within a low-level warm advection regime. Damaging winds may be the most common hazard, though low-level shear/SRH may become sufficient for a localized tornado threat as well. Convection may continue into late Saturday night with at least an isolated severe threat. Farther west, there is some potential for isolated storm development during the afternoon/evening across the northern Great Lakes vicinity, within a conditionally favorable environment. However, with large-scale ascent expected to remain rather nebulous in the wake of the departing MCS and shortwave trough, confidence is currently low regarding this scenario. ...Northern Plains into the Upper Midwest... While there is some lingering uncertainty regarding the influence of D1/Friday convection, strong to extreme buoyancy is likely to again develop across parts of the northern Plains and Upper Midwest, along and east of the cold front. However, very warm temperatures aloft and generally weak large-scale ascent may tend to suppress storm development across much of the strongly unstable warm sector. Strong heating could support isolated development across parts of NE/SD/eastern ND into northern MN near the surface low and front, which would conditionally pose a severe threat given the favorable parameter space. Farther northwest, guidance continues to vary regarding the magnitude of instability from eastern MT/northern WY into the western Dakotas. Strong morning convection will be possible across eastern MT, and some redevelopment may occur during the afternoon/evening, depending on the extent to which the departing MT shortwave trough can impinge upon favorable instability. A supercell or two will be possible, with a localized threat for all severe hazards. ..Dean.. 06/20/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Fri Jun 20 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY... ...SUMMARY... Severe thunderstorms are likely this afternoon into tonight from far eastern Montana eastward across the northern Plains and into the upper Mississippi Valley. Tornadoes, with one or two potentially strong, winds greater than 75 mph, and hailstones greater than 2 inches in diameter will be possible. Marginally severe storms will also be possible across parts of the northeast New Mexico and southeast Colorado. ...Northern Plains/Upper Mississippi Valley... A mid-level shortwave ridge will move eastward today from the northern Plains into the upper Mississippi Valley. In the wake of the ridge, a shortwave trough will move quickly east-northeastward across the northern Plains. At the surface, a low will deepen over northwestern South Dakota. To the north and northeast of the low, an east-to-west axis of low-level moisture will take shape by afternoon, along which surface dewpoints will be in the lower to mid 70s F. In response to surface heating, moderate to strong instability is expected to develop across much of the northern Plains by afternoon. Convection is first expected to initiate in far eastern Montana late this afternoon. From this convection, thunderstorms are forecast to rapidly grow upscale into a fast-moving linear MCS, with the track of the MCS moving eastward along a sharp gradient of instability. RAP late afternoon forecast soundings along the projected track of the MCS in southeastern North Dakota have MLCAPE around 4500 J/Kg, with 0-6 km shear near 60 knots. Lapse rates are forecast to be near 8 C/km, and 0-3 km storm relative helicity is forecast to be between 350 and 400 m2/s2. This environment should be favorable for all hazards, including tornadoes, large hail and wind damage. Tornadoes will be most likely with supercells and along the leading edge of bowing segments. A strong tornado or two will be possible. The more dominant supercells will also be capable of producing hailstones greater than 2 inches in diameter. A wind-damage threat should exist along the entire north-south length of the MCS, with a few gusts over 75 mph possible. The severe threat is expected to continue through this evening and into the overnight period as the MCS tracks eastward into the upper Mississippi Valley. Further southward across much of the Upper Midwest, a few warm-advection-related thunderstorms will be possible early in the day. Although these cells may be elevated, a marginal severe threat will be possible, with a potential for isolated severe gusts and hail. ...Northeast New Mexico/Southeast Colorado... Southwest mid-level flow will become established across the southern and central Rockies today. As surface temperatures warm, isolated to scattered thunderstorms are expected to develop in the higher terrain. These storms will move into the lower elevations late this afternoon into this evening. Although instability will be weak, low-level lapse rates will be very steep, around 9.5 C/Km in some areas. This could be enough for isolated severe gusts, associated with low-precipitation cells. ..Broyles/Moore.. 06/20/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Fri Jun 20 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY... ...SUMMARY... Severe thunderstorms are likely this afternoon into tonight from far eastern Montana eastward across the northern Plains and into the upper Mississippi Valley. Tornadoes, with one or two potentially strong, winds greater than 75 mph, and hailstones greater than 2 inches in diameter will be possible. Marginally severe storms will also be possible across parts of the northeast New Mexico and southeast Colorado. ...Northern Plains/Upper Mississippi Valley... A mid-level shortwave ridge will move eastward today from the northern Plains into the upper Mississippi Valley. In the wake of the ridge, a shortwave trough will move quickly east-northeastward across the northern Plains. At the surface, a low will deepen over northwestern South Dakota. To the north and northeast of the low, an east-to-west axis of low-level moisture will take shape by afternoon, along which surface dewpoints will be in the lower to mid 70s F. In response to surface heating, moderate to strong instability is expected to develop across much of the northern Plains by afternoon. Convection is first expected to initiate in far eastern Montana late this afternoon. From this convection, thunderstorms are forecast to rapidly grow upscale into a fast-moving linear MCS, with the track of the MCS moving eastward along a sharp gradient of instability. RAP late afternoon forecast soundings along the projected track of the MCS in southeastern North Dakota have MLCAPE around 4500 J/Kg, with 0-6 km shear near 60 knots. Lapse rates are forecast to be near 8 C/km, and 0-3 km storm relative helicity is forecast to be between 350 and 400 m2/s2. This environment should be favorable for all hazards, including tornadoes, large hail and wind damage. Tornadoes will be most likely with supercells and along the leading edge of bowing segments. A strong tornado or two will be possible. The more dominant supercells will also be capable of producing hailstones greater than 2 inches in diameter. A wind-damage threat should exist along the entire north-south length of the MCS, with a few gusts over 75 mph possible. The severe threat is expected to continue through this evening and into the overnight period as the MCS tracks eastward into the upper Mississippi Valley. Further southward across much of the Upper Midwest, a few warm-advection-related thunderstorms will be possible early in the day. Although these cells may be elevated, a marginal severe threat will be possible, with a potential for isolated severe gusts and hail. ...Northeast New Mexico/Southeast Colorado... Southwest mid-level flow will become established across the southern and central Rockies today. As surface temperatures warm, isolated to scattered thunderstorms are expected to develop in the higher terrain. These storms will move into the lower elevations late this afternoon into this evening. Although instability will be weak, low-level lapse rates will be very steep, around 9.5 C/Km in some areas. This could be enough for isolated severe gusts, associated with low-precipitation cells. ..Broyles/Moore.. 06/20/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Fri Jun 20 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY... ...SUMMARY... Severe thunderstorms are likely this afternoon into tonight from far eastern Montana eastward across the northern Plains and into the upper Mississippi Valley. Tornadoes, with one or two potentially strong, winds greater than 75 mph, and hailstones greater than 2 inches in diameter will be possible. Marginally severe storms will also be possible across parts of the northeast New Mexico and southeast Colorado. ...Northern Plains/Upper Mississippi Valley... A mid-level shortwave ridge will move eastward today from the northern Plains into the upper Mississippi Valley. In the wake of the ridge, a shortwave trough will move quickly east-northeastward across the northern Plains. At the surface, a low will deepen over northwestern South Dakota. To the north and northeast of the low, an east-to-west axis of low-level moisture will take shape by afternoon, along which surface dewpoints will be in the lower to mid 70s F. In response to surface heating, moderate to strong instability is expected to develop across much of the northern Plains by afternoon. Convection is first expected to initiate in far eastern Montana late this afternoon. From this convection, thunderstorms are forecast to rapidly grow upscale into a fast-moving linear MCS, with the track of the MCS moving eastward along a sharp gradient of instability. RAP late afternoon forecast soundings along the projected track of the MCS in southeastern North Dakota have MLCAPE around 4500 J/Kg, with 0-6 km shear near 60 knots. Lapse rates are forecast to be near 8 C/km, and 0-3 km storm relative helicity is forecast to be between 350 and 400 m2/s2. This environment should be favorable for all hazards, including tornadoes, large hail and wind damage. Tornadoes will be most likely with supercells and along the leading edge of bowing segments. A strong tornado or two will be possible. The more dominant supercells will also be capable of producing hailstones greater than 2 inches in diameter. A wind-damage threat should exist along the entire north-south length of the MCS, with a few gusts over 75 mph possible. The severe threat is expected to continue through this evening and into the overnight period as the MCS tracks eastward into the upper Mississippi Valley. Further southward across much of the Upper Midwest, a few warm-advection-related thunderstorms will be possible early in the day. Although these cells may be elevated, a marginal severe threat will be possible, with a potential for isolated severe gusts and hail. ...Northeast New Mexico/Southeast Colorado... Southwest mid-level flow will become established across the southern and central Rockies today. As surface temperatures warm, isolated to scattered thunderstorms are expected to develop in the higher terrain. These storms will move into the lower elevations late this afternoon into this evening. Although instability will be weak, low-level lapse rates will be very steep, around 9.5 C/Km in some areas. This could be enough for isolated severe gusts, associated with low-precipitation cells. ..Broyles/Moore.. 06/20/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Fri Jun 20 2025 Valid 201200Z - 211200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY... ...SUMMARY... Severe thunderstorms are likely this afternoon into tonight from far eastern Montana eastward across the northern Plains and into the upper Mississippi Valley. Tornadoes, with one or two potentially strong, winds greater than 75 mph, and hailstones greater than 2 inches in diameter will be possible. Marginally severe storms will also be possible across parts of the northeast New Mexico and southeast Colorado. ...Northern Plains/Upper Mississippi Valley... A mid-level shortwave ridge will move eastward today from the northern Plains into the upper Mississippi Valley. In the wake of the ridge, a shortwave trough will move quickly east-northeastward across the northern Plains. At the surface, a low will deepen over northwestern South Dakota. To the north and northeast of the low, an east-to-west axis of low-level moisture will take shape by afternoon, along which surface dewpoints will be in the lower to mid 70s F. In response to surface heating, moderate to strong instability is expected to develop across much of the northern Plains by afternoon. Convection is first expected to initiate in far eastern Montana late this afternoon. From this convection, thunderstorms are forecast to rapidly grow upscale into a fast-moving linear MCS, with the track of the MCS moving eastward along a sharp gradient of instability. RAP late afternoon forecast soundings along the projected track of the MCS in southeastern North Dakota have MLCAPE around 4500 J/Kg, with 0-6 km shear near 60 knots. Lapse rates are forecast to be near 8 C/km, and 0-3 km storm relative helicity is forecast to be between 350 and 400 m2/s2. This environment should be favorable for all hazards, including tornadoes, large hail and wind damage. Tornadoes will be most likely with supercells and along the leading edge of bowing segments. A strong tornado or two will be possible. The more dominant supercells will also be capable of producing hailstones greater than 2 inches in diameter. A wind-damage threat should exist along the entire north-south length of the MCS, with a few gusts over 75 mph possible. The severe threat is expected to continue through this evening and into the overnight period as the MCS tracks eastward into the upper Mississippi Valley. Further southward across much of the Upper Midwest, a few warm-advection-related thunderstorms will be possible early in the day. Although these cells may be elevated, a marginal severe threat will be possible, with a potential for isolated severe gusts and hail. ...Northeast New Mexico/Southeast Colorado... Southwest mid-level flow will become established across the southern and central Rockies today. As surface temperatures warm, isolated to scattered thunderstorms are expected to develop in the higher terrain. These storms will move into the lower elevations late this afternoon into this evening. Although instability will be weak, low-level lapse rates will be very steep, around 9.5 C/Km in some areas. This could be enough for isolated severe gusts, associated with low-precipitation cells. ..Broyles/Moore.. 06/20/2025 Read more