Severe Storms

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0155 PM CDT Fri Jun 20 2025 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL NEBRASKA INTO THE UPPER MIDWEST... ...SUMMARY... Severe thunderstorms may develop on Sunday from parts of the central and northern Plains into the upper Midwest. ...Synopsis... A strong mid-level ridge will amplify further across the eastern CONUS on Sunday with a weak mid-level shortwave trough traversing the northeast. A trough across the west will start to weaken and move into the northern Plains during the period. At the surface, troughing will extend along a frontal zone from northern Minnesota to the central High Plains on Sunday. ...Great Plains into the Upper Midwest... Very strong to extreme instability is forecast to develop across the central and northern Plains on Sunday. However, very warm low-mid level temperatures should keep the warm sector mostly capped for much of the day. Therefore, thunderstorm development should be mostly confined to the front. However, even along the frontal zone, storm coverage may be mostly isolated given that forcing from the mid-level trough may remain mostly northwest of the frontal zone. In addition, the strong mid-level flow is forecast to remain mostly post-frontal which may limit storm organization across Nebraska and South Dakota. Given the somewhat decoupled upper-level and low-level pattern, the severe storm threat is more conditional across eastern South Dakota, Nebraska, and southwest Minnesota with the higher probability storm threat across eastern North Dakota and northern Minnesota where cooler temperatures aloft, stronger shear, and stronger forcing should be present. Severe wind gusts would be the most likely threat from this activity. ...Parts of the Northeast... Storms may be ongoing at the beginning of the period across the Northeast as a mid-level shortwave trough shifts southeast. These storms could be marginally severe with some damaging wind threat. In the wake of this convection, very strong to extreme instability is expected to build into the Northeast, but very warm lower tropospheric temperatures and building heights aloft should suppress additional afternoon thunderstorms. ..Bentley.. 06/20/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0155 PM CDT Fri Jun 20 2025 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL NEBRASKA INTO THE UPPER MIDWEST... ...SUMMARY... Severe thunderstorms may develop on Sunday from parts of the central and northern Plains into the upper Midwest. ...Synopsis... A strong mid-level ridge will amplify further across the eastern CONUS on Sunday with a weak mid-level shortwave trough traversing the northeast. A trough across the west will start to weaken and move into the northern Plains during the period. At the surface, troughing will extend along a frontal zone from northern Minnesota to the central High Plains on Sunday. ...Great Plains into the Upper Midwest... Very strong to extreme instability is forecast to develop across the central and northern Plains on Sunday. However, very warm low-mid level temperatures should keep the warm sector mostly capped for much of the day. Therefore, thunderstorm development should be mostly confined to the front. However, even along the frontal zone, storm coverage may be mostly isolated given that forcing from the mid-level trough may remain mostly northwest of the frontal zone. In addition, the strong mid-level flow is forecast to remain mostly post-frontal which may limit storm organization across Nebraska and South Dakota. Given the somewhat decoupled upper-level and low-level pattern, the severe storm threat is more conditional across eastern South Dakota, Nebraska, and southwest Minnesota with the higher probability storm threat across eastern North Dakota and northern Minnesota where cooler temperatures aloft, stronger shear, and stronger forcing should be present. Severe wind gusts would be the most likely threat from this activity. ...Parts of the Northeast... Storms may be ongoing at the beginning of the period across the Northeast as a mid-level shortwave trough shifts southeast. These storms could be marginally severe with some damaging wind threat. In the wake of this convection, very strong to extreme instability is expected to build into the Northeast, but very warm lower tropospheric temperatures and building heights aloft should suppress additional afternoon thunderstorms. ..Bentley.. 06/20/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0155 PM CDT Fri Jun 20 2025 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL NEBRASKA INTO THE UPPER MIDWEST... ...SUMMARY... Severe thunderstorms may develop on Sunday from parts of the central and northern Plains into the upper Midwest. ...Synopsis... A strong mid-level ridge will amplify further across the eastern CONUS on Sunday with a weak mid-level shortwave trough traversing the northeast. A trough across the west will start to weaken and move into the northern Plains during the period. At the surface, troughing will extend along a frontal zone from northern Minnesota to the central High Plains on Sunday. ...Great Plains into the Upper Midwest... Very strong to extreme instability is forecast to develop across the central and northern Plains on Sunday. However, very warm low-mid level temperatures should keep the warm sector mostly capped for much of the day. Therefore, thunderstorm development should be mostly confined to the front. However, even along the frontal zone, storm coverage may be mostly isolated given that forcing from the mid-level trough may remain mostly northwest of the frontal zone. In addition, the strong mid-level flow is forecast to remain mostly post-frontal which may limit storm organization across Nebraska and South Dakota. Given the somewhat decoupled upper-level and low-level pattern, the severe storm threat is more conditional across eastern South Dakota, Nebraska, and southwest Minnesota with the higher probability storm threat across eastern North Dakota and northern Minnesota where cooler temperatures aloft, stronger shear, and stronger forcing should be present. Severe wind gusts would be the most likely threat from this activity. ...Parts of the Northeast... Storms may be ongoing at the beginning of the period across the Northeast as a mid-level shortwave trough shifts southeast. These storms could be marginally severe with some damaging wind threat. In the wake of this convection, very strong to extreme instability is expected to build into the Northeast, but very warm lower tropospheric temperatures and building heights aloft should suppress additional afternoon thunderstorms. ..Bentley.. 06/20/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0155 PM CDT Fri Jun 20 2025 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL NEBRASKA INTO THE UPPER MIDWEST... ...SUMMARY... Severe thunderstorms may develop on Sunday from parts of the central and northern Plains into the upper Midwest. ...Synopsis... A strong mid-level ridge will amplify further across the eastern CONUS on Sunday with a weak mid-level shortwave trough traversing the northeast. A trough across the west will start to weaken and move into the northern Plains during the period. At the surface, troughing will extend along a frontal zone from northern Minnesota to the central High Plains on Sunday. ...Great Plains into the Upper Midwest... Very strong to extreme instability is forecast to develop across the central and northern Plains on Sunday. However, very warm low-mid level temperatures should keep the warm sector mostly capped for much of the day. Therefore, thunderstorm development should be mostly confined to the front. However, even along the frontal zone, storm coverage may be mostly isolated given that forcing from the mid-level trough may remain mostly northwest of the frontal zone. In addition, the strong mid-level flow is forecast to remain mostly post-frontal which may limit storm organization across Nebraska and South Dakota. Given the somewhat decoupled upper-level and low-level pattern, the severe storm threat is more conditional across eastern South Dakota, Nebraska, and southwest Minnesota with the higher probability storm threat across eastern North Dakota and northern Minnesota where cooler temperatures aloft, stronger shear, and stronger forcing should be present. Severe wind gusts would be the most likely threat from this activity. ...Parts of the Northeast... Storms may be ongoing at the beginning of the period across the Northeast as a mid-level shortwave trough shifts southeast. These storms could be marginally severe with some damaging wind threat. In the wake of this convection, very strong to extreme instability is expected to build into the Northeast, but very warm lower tropospheric temperatures and building heights aloft should suppress additional afternoon thunderstorms. ..Bentley.. 06/20/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0155 PM CDT Fri Jun 20 2025 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL NEBRASKA INTO THE UPPER MIDWEST... ...SUMMARY... Severe thunderstorms may develop on Sunday from parts of the central and northern Plains into the upper Midwest. ...Synopsis... A strong mid-level ridge will amplify further across the eastern CONUS on Sunday with a weak mid-level shortwave trough traversing the northeast. A trough across the west will start to weaken and move into the northern Plains during the period. At the surface, troughing will extend along a frontal zone from northern Minnesota to the central High Plains on Sunday. ...Great Plains into the Upper Midwest... Very strong to extreme instability is forecast to develop across the central and northern Plains on Sunday. However, very warm low-mid level temperatures should keep the warm sector mostly capped for much of the day. Therefore, thunderstorm development should be mostly confined to the front. However, even along the frontal zone, storm coverage may be mostly isolated given that forcing from the mid-level trough may remain mostly northwest of the frontal zone. In addition, the strong mid-level flow is forecast to remain mostly post-frontal which may limit storm organization across Nebraska and South Dakota. Given the somewhat decoupled upper-level and low-level pattern, the severe storm threat is more conditional across eastern South Dakota, Nebraska, and southwest Minnesota with the higher probability storm threat across eastern North Dakota and northern Minnesota where cooler temperatures aloft, stronger shear, and stronger forcing should be present. Severe wind gusts would be the most likely threat from this activity. ...Parts of the Northeast... Storms may be ongoing at the beginning of the period across the Northeast as a mid-level shortwave trough shifts southeast. These storms could be marginally severe with some damaging wind threat. In the wake of this convection, very strong to extreme instability is expected to build into the Northeast, but very warm lower tropospheric temperatures and building heights aloft should suppress additional afternoon thunderstorms. ..Bentley.. 06/20/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0155 PM CDT Fri Jun 20 2025 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL NEBRASKA INTO THE UPPER MIDWEST... ...SUMMARY... Severe thunderstorms may develop on Sunday from parts of the central and northern Plains into the upper Midwest. ...Synopsis... A strong mid-level ridge will amplify further across the eastern CONUS on Sunday with a weak mid-level shortwave trough traversing the northeast. A trough across the west will start to weaken and move into the northern Plains during the period. At the surface, troughing will extend along a frontal zone from northern Minnesota to the central High Plains on Sunday. ...Great Plains into the Upper Midwest... Very strong to extreme instability is forecast to develop across the central and northern Plains on Sunday. However, very warm low-mid level temperatures should keep the warm sector mostly capped for much of the day. Therefore, thunderstorm development should be mostly confined to the front. However, even along the frontal zone, storm coverage may be mostly isolated given that forcing from the mid-level trough may remain mostly northwest of the frontal zone. In addition, the strong mid-level flow is forecast to remain mostly post-frontal which may limit storm organization across Nebraska and South Dakota. Given the somewhat decoupled upper-level and low-level pattern, the severe storm threat is more conditional across eastern South Dakota, Nebraska, and southwest Minnesota with the higher probability storm threat across eastern North Dakota and northern Minnesota where cooler temperatures aloft, stronger shear, and stronger forcing should be present. Severe wind gusts would be the most likely threat from this activity. ...Parts of the Northeast... Storms may be ongoing at the beginning of the period across the Northeast as a mid-level shortwave trough shifts southeast. These storms could be marginally severe with some damaging wind threat. In the wake of this convection, very strong to extreme instability is expected to build into the Northeast, but very warm lower tropospheric temperatures and building heights aloft should suppress additional afternoon thunderstorms. ..Bentley.. 06/20/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0155 PM CDT Fri Jun 20 2025 Valid 221200Z - 231200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL NEBRASKA INTO THE UPPER MIDWEST... ...SUMMARY... Severe thunderstorms may develop on Sunday from parts of the central and northern Plains into the upper Midwest. ...Synopsis... A strong mid-level ridge will amplify further across the eastern CONUS on Sunday with a weak mid-level shortwave trough traversing the northeast. A trough across the west will start to weaken and move into the northern Plains during the period. At the surface, troughing will extend along a frontal zone from northern Minnesota to the central High Plains on Sunday. ...Great Plains into the Upper Midwest... Very strong to extreme instability is forecast to develop across the central and northern Plains on Sunday. However, very warm low-mid level temperatures should keep the warm sector mostly capped for much of the day. Therefore, thunderstorm development should be mostly confined to the front. However, even along the frontal zone, storm coverage may be mostly isolated given that forcing from the mid-level trough may remain mostly northwest of the frontal zone. In addition, the strong mid-level flow is forecast to remain mostly post-frontal which may limit storm organization across Nebraska and South Dakota. Given the somewhat decoupled upper-level and low-level pattern, the severe storm threat is more conditional across eastern South Dakota, Nebraska, and southwest Minnesota with the higher probability storm threat across eastern North Dakota and northern Minnesota where cooler temperatures aloft, stronger shear, and stronger forcing should be present. Severe wind gusts would be the most likely threat from this activity. ...Parts of the Northeast... Storms may be ongoing at the beginning of the period across the Northeast as a mid-level shortwave trough shifts southeast. These storms could be marginally severe with some damaging wind threat. In the wake of this convection, very strong to extreme instability is expected to build into the Northeast, but very warm lower tropospheric temperatures and building heights aloft should suppress additional afternoon thunderstorms. ..Bentley.. 06/20/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NEW YORK AND NORTHERN PENNSYLVANIA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... An amplifying pattern will occur on Saturday with a trough strengthening across the west with a ridge building across the eastern CONUS. Surface high pressure will be present across the eastern CONUS with lee troughing across the central and northern Plains ahead of the strengthening western CONUS trough. ...Great Lakes into the Northeast... A strong MCS will likely be ongoing at the beginning of the period across northern Wisconsin/western Upper Michigan. This MCS will likely continue east through the morning with some wind/hail threat across Upper Michigan and northern Lower Michigan before eventually moving into Ontario. If this MCS continues to track along the instability gradient, it could eventually arrive across western/central New York during the afternoon/evening. However, this threat is conditional given stronger forcing farther north in Canada and strong building heights across the Northeast. Additional thunderstorms may develop along the trailing outflow/composite boundary during the afternoon as strong instability builds into the northern Great Lakes. However, building heights aloft should mostly suppress convection, with only isolated storm coverage expected, if at all. If any storms can develop, the environment would be very favorable for large hail, severe wind gusts, and perhaps a tornado. ...Northern Plains into the Upper Midwest... Very strong instability is expected to build across the northern Plains on Saturday afternoon/evening. Very warm 700mb temperatures (16C) and building heights aloft should keep thunderstorm activity suppressed for much of the period. However, strong heating could allow for isolated storm development which would likely be supercellular with a hail and wind threat if this conditional threat does materialize. A few strong to potentially severe storms may be ongoing at the beginning of the period across eastern Montana as a weak mid-level trough traverses the region. Storm activity will likely remain limited across eastern Montana for much of the day as heights build aloft. However, additional storms may develop early Sunday morning as troughing starts to advance east. Limited instability is the primary limiting factor, but if sufficient instability can develop, a few strong to severe storms may be possible (12Z NSSL WRF). ..Bentley.. 06/20/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NEW YORK AND NORTHERN PENNSYLVANIA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... An amplifying pattern will occur on Saturday with a trough strengthening across the west with a ridge building across the eastern CONUS. Surface high pressure will be present across the eastern CONUS with lee troughing across the central and northern Plains ahead of the strengthening western CONUS trough. ...Great Lakes into the Northeast... A strong MCS will likely be ongoing at the beginning of the period across northern Wisconsin/western Upper Michigan. This MCS will likely continue east through the morning with some wind/hail threat across Upper Michigan and northern Lower Michigan before eventually moving into Ontario. If this MCS continues to track along the instability gradient, it could eventually arrive across western/central New York during the afternoon/evening. However, this threat is conditional given stronger forcing farther north in Canada and strong building heights across the Northeast. Additional thunderstorms may develop along the trailing outflow/composite boundary during the afternoon as strong instability builds into the northern Great Lakes. However, building heights aloft should mostly suppress convection, with only isolated storm coverage expected, if at all. If any storms can develop, the environment would be very favorable for large hail, severe wind gusts, and perhaps a tornado. ...Northern Plains into the Upper Midwest... Very strong instability is expected to build across the northern Plains on Saturday afternoon/evening. Very warm 700mb temperatures (16C) and building heights aloft should keep thunderstorm activity suppressed for much of the period. However, strong heating could allow for isolated storm development which would likely be supercellular with a hail and wind threat if this conditional threat does materialize. A few strong to potentially severe storms may be ongoing at the beginning of the period across eastern Montana as a weak mid-level trough traverses the region. Storm activity will likely remain limited across eastern Montana for much of the day as heights build aloft. However, additional storms may develop early Sunday morning as troughing starts to advance east. Limited instability is the primary limiting factor, but if sufficient instability can develop, a few strong to severe storms may be possible (12Z NSSL WRF). ..Bentley.. 06/20/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NEW YORK AND NORTHERN PENNSYLVANIA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... An amplifying pattern will occur on Saturday with a trough strengthening across the west with a ridge building across the eastern CONUS. Surface high pressure will be present across the eastern CONUS with lee troughing across the central and northern Plains ahead of the strengthening western CONUS trough. ...Great Lakes into the Northeast... A strong MCS will likely be ongoing at the beginning of the period across northern Wisconsin/western Upper Michigan. This MCS will likely continue east through the morning with some wind/hail threat across Upper Michigan and northern Lower Michigan before eventually moving into Ontario. If this MCS continues to track along the instability gradient, it could eventually arrive across western/central New York during the afternoon/evening. However, this threat is conditional given stronger forcing farther north in Canada and strong building heights across the Northeast. Additional thunderstorms may develop along the trailing outflow/composite boundary during the afternoon as strong instability builds into the northern Great Lakes. However, building heights aloft should mostly suppress convection, with only isolated storm coverage expected, if at all. If any storms can develop, the environment would be very favorable for large hail, severe wind gusts, and perhaps a tornado. ...Northern Plains into the Upper Midwest... Very strong instability is expected to build across the northern Plains on Saturday afternoon/evening. Very warm 700mb temperatures (16C) and building heights aloft should keep thunderstorm activity suppressed for much of the period. However, strong heating could allow for isolated storm development which would likely be supercellular with a hail and wind threat if this conditional threat does materialize. A few strong to potentially severe storms may be ongoing at the beginning of the period across eastern Montana as a weak mid-level trough traverses the region. Storm activity will likely remain limited across eastern Montana for much of the day as heights build aloft. However, additional storms may develop early Sunday morning as troughing starts to advance east. Limited instability is the primary limiting factor, but if sufficient instability can develop, a few strong to severe storms may be possible (12Z NSSL WRF). ..Bentley.. 06/20/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NEW YORK AND NORTHERN PENNSYLVANIA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... An amplifying pattern will occur on Saturday with a trough strengthening across the west with a ridge building across the eastern CONUS. Surface high pressure will be present across the eastern CONUS with lee troughing across the central and northern Plains ahead of the strengthening western CONUS trough. ...Great Lakes into the Northeast... A strong MCS will likely be ongoing at the beginning of the period across northern Wisconsin/western Upper Michigan. This MCS will likely continue east through the morning with some wind/hail threat across Upper Michigan and northern Lower Michigan before eventually moving into Ontario. If this MCS continues to track along the instability gradient, it could eventually arrive across western/central New York during the afternoon/evening. However, this threat is conditional given stronger forcing farther north in Canada and strong building heights across the Northeast. Additional thunderstorms may develop along the trailing outflow/composite boundary during the afternoon as strong instability builds into the northern Great Lakes. However, building heights aloft should mostly suppress convection, with only isolated storm coverage expected, if at all. If any storms can develop, the environment would be very favorable for large hail, severe wind gusts, and perhaps a tornado. ...Northern Plains into the Upper Midwest... Very strong instability is expected to build across the northern Plains on Saturday afternoon/evening. Very warm 700mb temperatures (16C) and building heights aloft should keep thunderstorm activity suppressed for much of the period. However, strong heating could allow for isolated storm development which would likely be supercellular with a hail and wind threat if this conditional threat does materialize. A few strong to potentially severe storms may be ongoing at the beginning of the period across eastern Montana as a weak mid-level trough traverses the region. Storm activity will likely remain limited across eastern Montana for much of the day as heights build aloft. However, additional storms may develop early Sunday morning as troughing starts to advance east. Limited instability is the primary limiting factor, but if sufficient instability can develop, a few strong to severe storms may be possible (12Z NSSL WRF). ..Bentley.. 06/20/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NEW YORK AND NORTHERN PENNSYLVANIA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... An amplifying pattern will occur on Saturday with a trough strengthening across the west with a ridge building across the eastern CONUS. Surface high pressure will be present across the eastern CONUS with lee troughing across the central and northern Plains ahead of the strengthening western CONUS trough. ...Great Lakes into the Northeast... A strong MCS will likely be ongoing at the beginning of the period across northern Wisconsin/western Upper Michigan. This MCS will likely continue east through the morning with some wind/hail threat across Upper Michigan and northern Lower Michigan before eventually moving into Ontario. If this MCS continues to track along the instability gradient, it could eventually arrive across western/central New York during the afternoon/evening. However, this threat is conditional given stronger forcing farther north in Canada and strong building heights across the Northeast. Additional thunderstorms may develop along the trailing outflow/composite boundary during the afternoon as strong instability builds into the northern Great Lakes. However, building heights aloft should mostly suppress convection, with only isolated storm coverage expected, if at all. If any storms can develop, the environment would be very favorable for large hail, severe wind gusts, and perhaps a tornado. ...Northern Plains into the Upper Midwest... Very strong instability is expected to build across the northern Plains on Saturday afternoon/evening. Very warm 700mb temperatures (16C) and building heights aloft should keep thunderstorm activity suppressed for much of the period. However, strong heating could allow for isolated storm development which would likely be supercellular with a hail and wind threat if this conditional threat does materialize. A few strong to potentially severe storms may be ongoing at the beginning of the period across eastern Montana as a weak mid-level trough traverses the region. Storm activity will likely remain limited across eastern Montana for much of the day as heights build aloft. However, additional storms may develop early Sunday morning as troughing starts to advance east. Limited instability is the primary limiting factor, but if sufficient instability can develop, a few strong to severe storms may be possible (12Z NSSL WRF). ..Bentley.. 06/20/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NEW YORK AND NORTHERN PENNSYLVANIA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... An amplifying pattern will occur on Saturday with a trough strengthening across the west with a ridge building across the eastern CONUS. Surface high pressure will be present across the eastern CONUS with lee troughing across the central and northern Plains ahead of the strengthening western CONUS trough. ...Great Lakes into the Northeast... A strong MCS will likely be ongoing at the beginning of the period across northern Wisconsin/western Upper Michigan. This MCS will likely continue east through the morning with some wind/hail threat across Upper Michigan and northern Lower Michigan before eventually moving into Ontario. If this MCS continues to track along the instability gradient, it could eventually arrive across western/central New York during the afternoon/evening. However, this threat is conditional given stronger forcing farther north in Canada and strong building heights across the Northeast. Additional thunderstorms may develop along the trailing outflow/composite boundary during the afternoon as strong instability builds into the northern Great Lakes. However, building heights aloft should mostly suppress convection, with only isolated storm coverage expected, if at all. If any storms can develop, the environment would be very favorable for large hail, severe wind gusts, and perhaps a tornado. ...Northern Plains into the Upper Midwest... Very strong instability is expected to build across the northern Plains on Saturday afternoon/evening. Very warm 700mb temperatures (16C) and building heights aloft should keep thunderstorm activity suppressed for much of the period. However, strong heating could allow for isolated storm development which would likely be supercellular with a hail and wind threat if this conditional threat does materialize. A few strong to potentially severe storms may be ongoing at the beginning of the period across eastern Montana as a weak mid-level trough traverses the region. Storm activity will likely remain limited across eastern Montana for much of the day as heights build aloft. However, additional storms may develop early Sunday morning as troughing starts to advance east. Limited instability is the primary limiting factor, but if sufficient instability can develop, a few strong to severe storms may be possible (12Z NSSL WRF). ..Bentley.. 06/20/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NEW YORK AND NORTHERN PENNSYLVANIA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... An amplifying pattern will occur on Saturday with a trough strengthening across the west with a ridge building across the eastern CONUS. Surface high pressure will be present across the eastern CONUS with lee troughing across the central and northern Plains ahead of the strengthening western CONUS trough. ...Great Lakes into the Northeast... A strong MCS will likely be ongoing at the beginning of the period across northern Wisconsin/western Upper Michigan. This MCS will likely continue east through the morning with some wind/hail threat across Upper Michigan and northern Lower Michigan before eventually moving into Ontario. If this MCS continues to track along the instability gradient, it could eventually arrive across western/central New York during the afternoon/evening. However, this threat is conditional given stronger forcing farther north in Canada and strong building heights across the Northeast. Additional thunderstorms may develop along the trailing outflow/composite boundary during the afternoon as strong instability builds into the northern Great Lakes. However, building heights aloft should mostly suppress convection, with only isolated storm coverage expected, if at all. If any storms can develop, the environment would be very favorable for large hail, severe wind gusts, and perhaps a tornado. ...Northern Plains into the Upper Midwest... Very strong instability is expected to build across the northern Plains on Saturday afternoon/evening. Very warm 700mb temperatures (16C) and building heights aloft should keep thunderstorm activity suppressed for much of the period. However, strong heating could allow for isolated storm development which would likely be supercellular with a hail and wind threat if this conditional threat does materialize. A few strong to potentially severe storms may be ongoing at the beginning of the period across eastern Montana as a weak mid-level trough traverses the region. Storm activity will likely remain limited across eastern Montana for much of the day as heights build aloft. However, additional storms may develop early Sunday morning as troughing starts to advance east. Limited instability is the primary limiting factor, but if sufficient instability can develop, a few strong to severe storms may be possible (12Z NSSL WRF). ..Bentley.. 06/20/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NEW YORK AND NORTHERN PENNSYLVANIA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... An amplifying pattern will occur on Saturday with a trough strengthening across the west with a ridge building across the eastern CONUS. Surface high pressure will be present across the eastern CONUS with lee troughing across the central and northern Plains ahead of the strengthening western CONUS trough. ...Great Lakes into the Northeast... A strong MCS will likely be ongoing at the beginning of the period across northern Wisconsin/western Upper Michigan. This MCS will likely continue east through the morning with some wind/hail threat across Upper Michigan and northern Lower Michigan before eventually moving into Ontario. If this MCS continues to track along the instability gradient, it could eventually arrive across western/central New York during the afternoon/evening. However, this threat is conditional given stronger forcing farther north in Canada and strong building heights across the Northeast. Additional thunderstorms may develop along the trailing outflow/composite boundary during the afternoon as strong instability builds into the northern Great Lakes. However, building heights aloft should mostly suppress convection, with only isolated storm coverage expected, if at all. If any storms can develop, the environment would be very favorable for large hail, severe wind gusts, and perhaps a tornado. ...Northern Plains into the Upper Midwest... Very strong instability is expected to build across the northern Plains on Saturday afternoon/evening. Very warm 700mb temperatures (16C) and building heights aloft should keep thunderstorm activity suppressed for much of the period. However, strong heating could allow for isolated storm development which would likely be supercellular with a hail and wind threat if this conditional threat does materialize. A few strong to potentially severe storms may be ongoing at the beginning of the period across eastern Montana as a weak mid-level trough traverses the region. Storm activity will likely remain limited across eastern Montana for much of the day as heights build aloft. However, additional storms may develop early Sunday morning as troughing starts to advance east. Limited instability is the primary limiting factor, but if sufficient instability can develop, a few strong to severe storms may be possible (12Z NSSL WRF). ..Bentley.. 06/20/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NEW YORK AND NORTHERN PENNSYLVANIA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... An amplifying pattern will occur on Saturday with a trough strengthening across the west with a ridge building across the eastern CONUS. Surface high pressure will be present across the eastern CONUS with lee troughing across the central and northern Plains ahead of the strengthening western CONUS trough. ...Great Lakes into the Northeast... A strong MCS will likely be ongoing at the beginning of the period across northern Wisconsin/western Upper Michigan. This MCS will likely continue east through the morning with some wind/hail threat across Upper Michigan and northern Lower Michigan before eventually moving into Ontario. If this MCS continues to track along the instability gradient, it could eventually arrive across western/central New York during the afternoon/evening. However, this threat is conditional given stronger forcing farther north in Canada and strong building heights across the Northeast. Additional thunderstorms may develop along the trailing outflow/composite boundary during the afternoon as strong instability builds into the northern Great Lakes. However, building heights aloft should mostly suppress convection, with only isolated storm coverage expected, if at all. If any storms can develop, the environment would be very favorable for large hail, severe wind gusts, and perhaps a tornado. ...Northern Plains into the Upper Midwest... Very strong instability is expected to build across the northern Plains on Saturday afternoon/evening. Very warm 700mb temperatures (16C) and building heights aloft should keep thunderstorm activity suppressed for much of the period. However, strong heating could allow for isolated storm development which would likely be supercellular with a hail and wind threat if this conditional threat does materialize. A few strong to potentially severe storms may be ongoing at the beginning of the period across eastern Montana as a weak mid-level trough traverses the region. Storm activity will likely remain limited across eastern Montana for much of the day as heights build aloft. However, additional storms may develop early Sunday morning as troughing starts to advance east. Limited instability is the primary limiting factor, but if sufficient instability can develop, a few strong to severe storms may be possible (12Z NSSL WRF). ..Bentley.. 06/20/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NEW YORK AND NORTHERN PENNSYLVANIA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... An amplifying pattern will occur on Saturday with a trough strengthening across the west with a ridge building across the eastern CONUS. Surface high pressure will be present across the eastern CONUS with lee troughing across the central and northern Plains ahead of the strengthening western CONUS trough. ...Great Lakes into the Northeast... A strong MCS will likely be ongoing at the beginning of the period across northern Wisconsin/western Upper Michigan. This MCS will likely continue east through the morning with some wind/hail threat across Upper Michigan and northern Lower Michigan before eventually moving into Ontario. If this MCS continues to track along the instability gradient, it could eventually arrive across western/central New York during the afternoon/evening. However, this threat is conditional given stronger forcing farther north in Canada and strong building heights across the Northeast. Additional thunderstorms may develop along the trailing outflow/composite boundary during the afternoon as strong instability builds into the northern Great Lakes. However, building heights aloft should mostly suppress convection, with only isolated storm coverage expected, if at all. If any storms can develop, the environment would be very favorable for large hail, severe wind gusts, and perhaps a tornado. ...Northern Plains into the Upper Midwest... Very strong instability is expected to build across the northern Plains on Saturday afternoon/evening. Very warm 700mb temperatures (16C) and building heights aloft should keep thunderstorm activity suppressed for much of the period. However, strong heating could allow for isolated storm development which would likely be supercellular with a hail and wind threat if this conditional threat does materialize. A few strong to potentially severe storms may be ongoing at the beginning of the period across eastern Montana as a weak mid-level trough traverses the region. Storm activity will likely remain limited across eastern Montana for much of the day as heights build aloft. However, additional storms may develop early Sunday morning as troughing starts to advance east. Limited instability is the primary limiting factor, but if sufficient instability can develop, a few strong to severe storms may be possible (12Z NSSL WRF). ..Bentley.. 06/20/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NEW YORK AND NORTHERN PENNSYLVANIA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... An amplifying pattern will occur on Saturday with a trough strengthening across the west with a ridge building across the eastern CONUS. Surface high pressure will be present across the eastern CONUS with lee troughing across the central and northern Plains ahead of the strengthening western CONUS trough. ...Great Lakes into the Northeast... A strong MCS will likely be ongoing at the beginning of the period across northern Wisconsin/western Upper Michigan. This MCS will likely continue east through the morning with some wind/hail threat across Upper Michigan and northern Lower Michigan before eventually moving into Ontario. If this MCS continues to track along the instability gradient, it could eventually arrive across western/central New York during the afternoon/evening. However, this threat is conditional given stronger forcing farther north in Canada and strong building heights across the Northeast. Additional thunderstorms may develop along the trailing outflow/composite boundary during the afternoon as strong instability builds into the northern Great Lakes. However, building heights aloft should mostly suppress convection, with only isolated storm coverage expected, if at all. If any storms can develop, the environment would be very favorable for large hail, severe wind gusts, and perhaps a tornado. ...Northern Plains into the Upper Midwest... Very strong instability is expected to build across the northern Plains on Saturday afternoon/evening. Very warm 700mb temperatures (16C) and building heights aloft should keep thunderstorm activity suppressed for much of the period. However, strong heating could allow for isolated storm development which would likely be supercellular with a hail and wind threat if this conditional threat does materialize. A few strong to potentially severe storms may be ongoing at the beginning of the period across eastern Montana as a weak mid-level trough traverses the region. Storm activity will likely remain limited across eastern Montana for much of the day as heights build aloft. However, additional storms may develop early Sunday morning as troughing starts to advance east. Limited instability is the primary limiting factor, but if sufficient instability can develop, a few strong to severe storms may be possible (12Z NSSL WRF). ..Bentley.. 06/20/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NEW YORK AND NORTHERN PENNSYLVANIA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... An amplifying pattern will occur on Saturday with a trough strengthening across the west with a ridge building across the eastern CONUS. Surface high pressure will be present across the eastern CONUS with lee troughing across the central and northern Plains ahead of the strengthening western CONUS trough. ...Great Lakes into the Northeast... A strong MCS will likely be ongoing at the beginning of the period across northern Wisconsin/western Upper Michigan. This MCS will likely continue east through the morning with some wind/hail threat across Upper Michigan and northern Lower Michigan before eventually moving into Ontario. If this MCS continues to track along the instability gradient, it could eventually arrive across western/central New York during the afternoon/evening. However, this threat is conditional given stronger forcing farther north in Canada and strong building heights across the Northeast. Additional thunderstorms may develop along the trailing outflow/composite boundary during the afternoon as strong instability builds into the northern Great Lakes. However, building heights aloft should mostly suppress convection, with only isolated storm coverage expected, if at all. If any storms can develop, the environment would be very favorable for large hail, severe wind gusts, and perhaps a tornado. ...Northern Plains into the Upper Midwest... Very strong instability is expected to build across the northern Plains on Saturday afternoon/evening. Very warm 700mb temperatures (16C) and building heights aloft should keep thunderstorm activity suppressed for much of the period. However, strong heating could allow for isolated storm development which would likely be supercellular with a hail and wind threat if this conditional threat does materialize. A few strong to potentially severe storms may be ongoing at the beginning of the period across eastern Montana as a weak mid-level trough traverses the region. Storm activity will likely remain limited across eastern Montana for much of the day as heights build aloft. However, additional storms may develop early Sunday morning as troughing starts to advance east. Limited instability is the primary limiting factor, but if sufficient instability can develop, a few strong to severe storms may be possible (12Z NSSL WRF). ..Bentley.. 06/20/2025 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Fri Jun 20 2025 Valid 211200Z - 221200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN GREAT LAKES INTO NEW YORK AND NORTHERN PENNSYLVANIA... ...SUMMARY... Strong to locally severe storms are possible Saturday from the northern Great Plains into the Upper Midwest and Great Lakes. ...Synopsis... An amplifying pattern will occur on Saturday with a trough strengthening across the west with a ridge building across the eastern CONUS. Surface high pressure will be present across the eastern CONUS with lee troughing across the central and northern Plains ahead of the strengthening western CONUS trough. ...Great Lakes into the Northeast... A strong MCS will likely be ongoing at the beginning of the period across northern Wisconsin/western Upper Michigan. This MCS will likely continue east through the morning with some wind/hail threat across Upper Michigan and northern Lower Michigan before eventually moving into Ontario. If this MCS continues to track along the instability gradient, it could eventually arrive across western/central New York during the afternoon/evening. However, this threat is conditional given stronger forcing farther north in Canada and strong building heights across the Northeast. Additional thunderstorms may develop along the trailing outflow/composite boundary during the afternoon as strong instability builds into the northern Great Lakes. However, building heights aloft should mostly suppress convection, with only isolated storm coverage expected, if at all. If any storms can develop, the environment would be very favorable for large hail, severe wind gusts, and perhaps a tornado. ...Northern Plains into the Upper Midwest... Very strong instability is expected to build across the northern Plains on Saturday afternoon/evening. Very warm 700mb temperatures (16C) and building heights aloft should keep thunderstorm activity suppressed for much of the period. However, strong heating could allow for isolated storm development which would likely be supercellular with a hail and wind threat if this conditional threat does materialize. A few strong to potentially severe storms may be ongoing at the beginning of the period across eastern Montana as a weak mid-level trough traverses the region. Storm activity will likely remain limited across eastern Montana for much of the day as heights build aloft. However, additional storms may develop early Sunday morning as troughing starts to advance east. Limited instability is the primary limiting factor, but if sufficient instability can develop, a few strong to severe storms may be possible (12Z NSSL WRF). ..Bentley.. 06/20/2025 Read more