Severe Storms

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Thu Jul 03 2025 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL PLAINS TO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe thunderstorms are expected across portions of the northern Plains and Upper Midwest on Friday. ...Synopsis... A strong upper-trough will move off the northeast CONUS into the western Atlantic on Friday. Meanwhile, a ridge will move across the Great Lakes with a trough across the northern Plains into the Upper Midwest. An additional mid-level trough will move across the Northwest. ...Central Plains into the Upper Midwest... As a mid-level trough moves across the northern Plains, a surface low will deepen across eastern North Dakota on Friday. Ahead of this surface low and associated cold front, strong instability is forecast with dewpoints in the low 70s and temperatures in the low 80s. Widespread thunderstorm activity is anticipated along this frontal zone as ascent overspreads the front with an uncapped warm sector. Some embedded shortwave jet streaks will move through the southwesterly flow across the warm sector. Within these zones of stronger mid-level flow, shear may be more favorable and support a greater severe weather threat. However, the locations of these mesoscale regions with a more favorable environment remain uncertain at this time. ...ID/MT... A strong shortwave trough will track into the western states on Friday, promoting scattered afternoon thunderstorm development over parts of the northern Great Basin and northern Rockies. There is some concern for a few storms capable of damaging winds and hail over the region Friday evening, but model solutions remain to diverse to add a risk area at this time. ..Bentley.. 07/03/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Thu Jul 03 2025 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL PLAINS TO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe thunderstorms are expected across portions of the northern Plains and Upper Midwest on Friday. ...Synopsis... A strong upper-trough will move off the northeast CONUS into the western Atlantic on Friday. Meanwhile, a ridge will move across the Great Lakes with a trough across the northern Plains into the Upper Midwest. An additional mid-level trough will move across the Northwest. ...Central Plains into the Upper Midwest... As a mid-level trough moves across the northern Plains, a surface low will deepen across eastern North Dakota on Friday. Ahead of this surface low and associated cold front, strong instability is forecast with dewpoints in the low 70s and temperatures in the low 80s. Widespread thunderstorm activity is anticipated along this frontal zone as ascent overspreads the front with an uncapped warm sector. Some embedded shortwave jet streaks will move through the southwesterly flow across the warm sector. Within these zones of stronger mid-level flow, shear may be more favorable and support a greater severe weather threat. However, the locations of these mesoscale regions with a more favorable environment remain uncertain at this time. ...ID/MT... A strong shortwave trough will track into the western states on Friday, promoting scattered afternoon thunderstorm development over parts of the northern Great Basin and northern Rockies. There is some concern for a few storms capable of damaging winds and hail over the region Friday evening, but model solutions remain to diverse to add a risk area at this time. ..Bentley.. 07/03/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Thu Jul 03 2025 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL PLAINS TO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe thunderstorms are expected across portions of the northern Plains and Upper Midwest on Friday. ...Synopsis... A strong upper-trough will move off the northeast CONUS into the western Atlantic on Friday. Meanwhile, a ridge will move across the Great Lakes with a trough across the northern Plains into the Upper Midwest. An additional mid-level trough will move across the Northwest. ...Central Plains into the Upper Midwest... As a mid-level trough moves across the northern Plains, a surface low will deepen across eastern North Dakota on Friday. Ahead of this surface low and associated cold front, strong instability is forecast with dewpoints in the low 70s and temperatures in the low 80s. Widespread thunderstorm activity is anticipated along this frontal zone as ascent overspreads the front with an uncapped warm sector. Some embedded shortwave jet streaks will move through the southwesterly flow across the warm sector. Within these zones of stronger mid-level flow, shear may be more favorable and support a greater severe weather threat. However, the locations of these mesoscale regions with a more favorable environment remain uncertain at this time. ...ID/MT... A strong shortwave trough will track into the western states on Friday, promoting scattered afternoon thunderstorm development over parts of the northern Great Basin and northern Rockies. There is some concern for a few storms capable of damaging winds and hail over the region Friday evening, but model solutions remain to diverse to add a risk area at this time. ..Bentley.. 07/03/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Thu Jul 03 2025 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL PLAINS TO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe thunderstorms are expected across portions of the northern Plains and Upper Midwest on Friday. ...Synopsis... A strong upper-trough will move off the northeast CONUS into the western Atlantic on Friday. Meanwhile, a ridge will move across the Great Lakes with a trough across the northern Plains into the Upper Midwest. An additional mid-level trough will move across the Northwest. ...Central Plains into the Upper Midwest... As a mid-level trough moves across the northern Plains, a surface low will deepen across eastern North Dakota on Friday. Ahead of this surface low and associated cold front, strong instability is forecast with dewpoints in the low 70s and temperatures in the low 80s. Widespread thunderstorm activity is anticipated along this frontal zone as ascent overspreads the front with an uncapped warm sector. Some embedded shortwave jet streaks will move through the southwesterly flow across the warm sector. Within these zones of stronger mid-level flow, shear may be more favorable and support a greater severe weather threat. However, the locations of these mesoscale regions with a more favorable environment remain uncertain at this time. ...ID/MT... A strong shortwave trough will track into the western states on Friday, promoting scattered afternoon thunderstorm development over parts of the northern Great Basin and northern Rockies. There is some concern for a few storms capable of damaging winds and hail over the region Friday evening, but model solutions remain to diverse to add a risk area at this time. ..Bentley.. 07/03/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Thu Jul 03 2025 Valid 041200Z - 051200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL PLAINS TO THE UPPER MIDWEST... ...SUMMARY... Scattered strong to severe thunderstorms are expected across portions of the northern Plains and Upper Midwest on Friday. ...Synopsis... A strong upper-trough will move off the northeast CONUS into the western Atlantic on Friday. Meanwhile, a ridge will move across the Great Lakes with a trough across the northern Plains into the Upper Midwest. An additional mid-level trough will move across the Northwest. ...Central Plains into the Upper Midwest... As a mid-level trough moves across the northern Plains, a surface low will deepen across eastern North Dakota on Friday. Ahead of this surface low and associated cold front, strong instability is forecast with dewpoints in the low 70s and temperatures in the low 80s. Widespread thunderstorm activity is anticipated along this frontal zone as ascent overspreads the front with an uncapped warm sector. Some embedded shortwave jet streaks will move through the southwesterly flow across the warm sector. Within these zones of stronger mid-level flow, shear may be more favorable and support a greater severe weather threat. However, the locations of these mesoscale regions with a more favorable environment remain uncertain at this time. ...ID/MT... A strong shortwave trough will track into the western states on Friday, promoting scattered afternoon thunderstorm development over parts of the northern Great Basin and northern Rockies. There is some concern for a few storms capable of damaging winds and hail over the region Friday evening, but model solutions remain to diverse to add a risk area at this time. ..Bentley.. 07/03/2025 Read more

MD 1545 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHEAST SD...NORTHEAST NE...NORTHWEST IA...AND FAR SOUTHWEST MN
Mesoscale Discussion 1545 NWS Storm Prediction Center Norman OK 1152 PM CDT Wed Jul 02 2025 Areas affected...Southeast SD...northeast NE...northwest IA...and far southwest MN Concerning...Severe potential...Watch unlikely Valid 030452Z - 030645Z Probability of Watch Issuance...5 percent SUMMARY...Isolated instances of severe hail will be possible with the stronger storms tonight. DISCUSSION...In response to weak low-level warm advection, isolated thunderstorms are developing along the northeastern periphery of a large-scale ridge. Here, 30-40 kt of midlevel northwesterly flow is yielding an elongated/mostly straight hodograph (around 30 kt of effective shear). This wind profile, coupled with an influx of steep midlevel lapse rates atop a shallow low-level stable layer, may support a couple elevated/transient supercell structures -- capable of producing isolated severe hail. Given the weak forcing for ascent, storm longevity and overall evolution is uncertain. ..Weinman/Guyer.. 07/03/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DMX...FSD...OAX...LBF... LAT...LON 42229747 43049896 43489895 44059853 44239784 44049706 43639595 43099519 42469511 42069558 41969661 42229747 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1230 AM CDT Thu Jul 03 2025 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHEAST AND NORTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... An upper trough with an embedded 40-50 kt mid-level speed maximum will pivot across the Northeast today. A related surface cold front will likewise develop eastward across this region through the afternoon/evening. Filtered daytime heating of a seasonably moist low-level airmass will support the development of moderate instability along/ahead of the cold front by late morning/early afternoon. Aided by the enhanced mid-level flow, deep-layer shear will likely be strong enough to support updraft organization, including a mix of multicells and perhaps some supercells. Scattered severe/damaging winds should be the primary severe threat as low-level lapse rates gradually steepen. But, some large hail may occur given favorable shear, especially if any supercells can be sustained. The Slight Risk has been expanded northward to include more of New England, as recent guidance trends show potential for organized severe convection along/ahead much of the length of the front. ...Northern Plains... An upper ridge will persist over much of the Plains today. Even so, a weak mid-level disturbance is forecast to advance eastward from MT across the northern Plains this afternoon/evening on the northern periphery of the upper ridge. This feature should encourage isolated to scattered intense thunderstorm development along/near a warm front extending across parts of ND by late afternoon/early evening. Moderate to strong instability is expected along/near this boundary, aided by steep lapse rates aloft. Modest low-level southerly flow is forecast to gradually veer and strengthen with height through mid/upper levels. This will support sufficient deep-layer shear (30-40 kt) for organized convection, including some supercells initially across western/central ND. These supercells should pose a threat for scattered large hail, some of which may be 2+ inches in diameter given a rather favorable thermodynamic environment forecast. With time this evening, there may be some potential for upscale growth into a small bowing cluster with eastward extent into central/eastern ND. If this mode transition occurs, then the severe/damaging wind threat would likewise increase. Although low-level flow should remain fairly modest, a tornado or two also appears possible, particularly along/near the front where effective SRH should be locally enhanced. ...Upper Midwest... Compared to the northern Plains, there is generally less confidence in overall thunderstorm coverage and development across much of the Upper Midwest through the period. Weak forcing aloft and the persistence of the upper ridge should tend to limit convective development in an otherwise moderately to strongly unstable airmass. Still, any thunderstorms which can develop, perhaps aided by modest low-level warm advection this evening/tonight, could pose an isolated severe hail/wind threat. The Marginal Risk area has been adjusted northward/westward some based on latest guidance trends showing multiple potential zones of isolated strong/severe thunderstorms. ..Gleason/Lyons.. 07/03/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1230 AM CDT Thu Jul 03 2025 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHEAST AND NORTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... An upper trough with an embedded 40-50 kt mid-level speed maximum will pivot across the Northeast today. A related surface cold front will likewise develop eastward across this region through the afternoon/evening. Filtered daytime heating of a seasonably moist low-level airmass will support the development of moderate instability along/ahead of the cold front by late morning/early afternoon. Aided by the enhanced mid-level flow, deep-layer shear will likely be strong enough to support updraft organization, including a mix of multicells and perhaps some supercells. Scattered severe/damaging winds should be the primary severe threat as low-level lapse rates gradually steepen. But, some large hail may occur given favorable shear, especially if any supercells can be sustained. The Slight Risk has been expanded northward to include more of New England, as recent guidance trends show potential for organized severe convection along/ahead much of the length of the front. ...Northern Plains... An upper ridge will persist over much of the Plains today. Even so, a weak mid-level disturbance is forecast to advance eastward from MT across the northern Plains this afternoon/evening on the northern periphery of the upper ridge. This feature should encourage isolated to scattered intense thunderstorm development along/near a warm front extending across parts of ND by late afternoon/early evening. Moderate to strong instability is expected along/near this boundary, aided by steep lapse rates aloft. Modest low-level southerly flow is forecast to gradually veer and strengthen with height through mid/upper levels. This will support sufficient deep-layer shear (30-40 kt) for organized convection, including some supercells initially across western/central ND. These supercells should pose a threat for scattered large hail, some of which may be 2+ inches in diameter given a rather favorable thermodynamic environment forecast. With time this evening, there may be some potential for upscale growth into a small bowing cluster with eastward extent into central/eastern ND. If this mode transition occurs, then the severe/damaging wind threat would likewise increase. Although low-level flow should remain fairly modest, a tornado or two also appears possible, particularly along/near the front where effective SRH should be locally enhanced. ...Upper Midwest... Compared to the northern Plains, there is generally less confidence in overall thunderstorm coverage and development across much of the Upper Midwest through the period. Weak forcing aloft and the persistence of the upper ridge should tend to limit convective development in an otherwise moderately to strongly unstable airmass. Still, any thunderstorms which can develop, perhaps aided by modest low-level warm advection this evening/tonight, could pose an isolated severe hail/wind threat. The Marginal Risk area has been adjusted northward/westward some based on latest guidance trends showing multiple potential zones of isolated strong/severe thunderstorms. ..Gleason/Lyons.. 07/03/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1230 AM CDT Thu Jul 03 2025 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHEAST AND NORTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... An upper trough with an embedded 40-50 kt mid-level speed maximum will pivot across the Northeast today. A related surface cold front will likewise develop eastward across this region through the afternoon/evening. Filtered daytime heating of a seasonably moist low-level airmass will support the development of moderate instability along/ahead of the cold front by late morning/early afternoon. Aided by the enhanced mid-level flow, deep-layer shear will likely be strong enough to support updraft organization, including a mix of multicells and perhaps some supercells. Scattered severe/damaging winds should be the primary severe threat as low-level lapse rates gradually steepen. But, some large hail may occur given favorable shear, especially if any supercells can be sustained. The Slight Risk has been expanded northward to include more of New England, as recent guidance trends show potential for organized severe convection along/ahead much of the length of the front. ...Northern Plains... An upper ridge will persist over much of the Plains today. Even so, a weak mid-level disturbance is forecast to advance eastward from MT across the northern Plains this afternoon/evening on the northern periphery of the upper ridge. This feature should encourage isolated to scattered intense thunderstorm development along/near a warm front extending across parts of ND by late afternoon/early evening. Moderate to strong instability is expected along/near this boundary, aided by steep lapse rates aloft. Modest low-level southerly flow is forecast to gradually veer and strengthen with height through mid/upper levels. This will support sufficient deep-layer shear (30-40 kt) for organized convection, including some supercells initially across western/central ND. These supercells should pose a threat for scattered large hail, some of which may be 2+ inches in diameter given a rather favorable thermodynamic environment forecast. With time this evening, there may be some potential for upscale growth into a small bowing cluster with eastward extent into central/eastern ND. If this mode transition occurs, then the severe/damaging wind threat would likewise increase. Although low-level flow should remain fairly modest, a tornado or two also appears possible, particularly along/near the front where effective SRH should be locally enhanced. ...Upper Midwest... Compared to the northern Plains, there is generally less confidence in overall thunderstorm coverage and development across much of the Upper Midwest through the period. Weak forcing aloft and the persistence of the upper ridge should tend to limit convective development in an otherwise moderately to strongly unstable airmass. Still, any thunderstorms which can develop, perhaps aided by modest low-level warm advection this evening/tonight, could pose an isolated severe hail/wind threat. The Marginal Risk area has been adjusted northward/westward some based on latest guidance trends showing multiple potential zones of isolated strong/severe thunderstorms. ..Gleason/Lyons.. 07/03/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1230 AM CDT Thu Jul 03 2025 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHEAST AND NORTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... An upper trough with an embedded 40-50 kt mid-level speed maximum will pivot across the Northeast today. A related surface cold front will likewise develop eastward across this region through the afternoon/evening. Filtered daytime heating of a seasonably moist low-level airmass will support the development of moderate instability along/ahead of the cold front by late morning/early afternoon. Aided by the enhanced mid-level flow, deep-layer shear will likely be strong enough to support updraft organization, including a mix of multicells and perhaps some supercells. Scattered severe/damaging winds should be the primary severe threat as low-level lapse rates gradually steepen. But, some large hail may occur given favorable shear, especially if any supercells can be sustained. The Slight Risk has been expanded northward to include more of New England, as recent guidance trends show potential for organized severe convection along/ahead much of the length of the front. ...Northern Plains... An upper ridge will persist over much of the Plains today. Even so, a weak mid-level disturbance is forecast to advance eastward from MT across the northern Plains this afternoon/evening on the northern periphery of the upper ridge. This feature should encourage isolated to scattered intense thunderstorm development along/near a warm front extending across parts of ND by late afternoon/early evening. Moderate to strong instability is expected along/near this boundary, aided by steep lapse rates aloft. Modest low-level southerly flow is forecast to gradually veer and strengthen with height through mid/upper levels. This will support sufficient deep-layer shear (30-40 kt) for organized convection, including some supercells initially across western/central ND. These supercells should pose a threat for scattered large hail, some of which may be 2+ inches in diameter given a rather favorable thermodynamic environment forecast. With time this evening, there may be some potential for upscale growth into a small bowing cluster with eastward extent into central/eastern ND. If this mode transition occurs, then the severe/damaging wind threat would likewise increase. Although low-level flow should remain fairly modest, a tornado or two also appears possible, particularly along/near the front where effective SRH should be locally enhanced. ...Upper Midwest... Compared to the northern Plains, there is generally less confidence in overall thunderstorm coverage and development across much of the Upper Midwest through the period. Weak forcing aloft and the persistence of the upper ridge should tend to limit convective development in an otherwise moderately to strongly unstable airmass. Still, any thunderstorms which can develop, perhaps aided by modest low-level warm advection this evening/tonight, could pose an isolated severe hail/wind threat. The Marginal Risk area has been adjusted northward/westward some based on latest guidance trends showing multiple potential zones of isolated strong/severe thunderstorms. ..Gleason/Lyons.. 07/03/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1230 AM CDT Thu Jul 03 2025 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHEAST AND NORTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... An upper trough with an embedded 40-50 kt mid-level speed maximum will pivot across the Northeast today. A related surface cold front will likewise develop eastward across this region through the afternoon/evening. Filtered daytime heating of a seasonably moist low-level airmass will support the development of moderate instability along/ahead of the cold front by late morning/early afternoon. Aided by the enhanced mid-level flow, deep-layer shear will likely be strong enough to support updraft organization, including a mix of multicells and perhaps some supercells. Scattered severe/damaging winds should be the primary severe threat as low-level lapse rates gradually steepen. But, some large hail may occur given favorable shear, especially if any supercells can be sustained. The Slight Risk has been expanded northward to include more of New England, as recent guidance trends show potential for organized severe convection along/ahead much of the length of the front. ...Northern Plains... An upper ridge will persist over much of the Plains today. Even so, a weak mid-level disturbance is forecast to advance eastward from MT across the northern Plains this afternoon/evening on the northern periphery of the upper ridge. This feature should encourage isolated to scattered intense thunderstorm development along/near a warm front extending across parts of ND by late afternoon/early evening. Moderate to strong instability is expected along/near this boundary, aided by steep lapse rates aloft. Modest low-level southerly flow is forecast to gradually veer and strengthen with height through mid/upper levels. This will support sufficient deep-layer shear (30-40 kt) for organized convection, including some supercells initially across western/central ND. These supercells should pose a threat for scattered large hail, some of which may be 2+ inches in diameter given a rather favorable thermodynamic environment forecast. With time this evening, there may be some potential for upscale growth into a small bowing cluster with eastward extent into central/eastern ND. If this mode transition occurs, then the severe/damaging wind threat would likewise increase. Although low-level flow should remain fairly modest, a tornado or two also appears possible, particularly along/near the front where effective SRH should be locally enhanced. ...Upper Midwest... Compared to the northern Plains, there is generally less confidence in overall thunderstorm coverage and development across much of the Upper Midwest through the period. Weak forcing aloft and the persistence of the upper ridge should tend to limit convective development in an otherwise moderately to strongly unstable airmass. Still, any thunderstorms which can develop, perhaps aided by modest low-level warm advection this evening/tonight, could pose an isolated severe hail/wind threat. The Marginal Risk area has been adjusted northward/westward some based on latest guidance trends showing multiple potential zones of isolated strong/severe thunderstorms. ..Gleason/Lyons.. 07/03/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1230 AM CDT Thu Jul 03 2025 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE NORTHEAST AND NORTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms capable of producing severe/damaging winds and large hail are forecast across parts of the Northeast and northern Plains today. ...Northeast... An upper trough with an embedded 40-50 kt mid-level speed maximum will pivot across the Northeast today. A related surface cold front will likewise develop eastward across this region through the afternoon/evening. Filtered daytime heating of a seasonably moist low-level airmass will support the development of moderate instability along/ahead of the cold front by late morning/early afternoon. Aided by the enhanced mid-level flow, deep-layer shear will likely be strong enough to support updraft organization, including a mix of multicells and perhaps some supercells. Scattered severe/damaging winds should be the primary severe threat as low-level lapse rates gradually steepen. But, some large hail may occur given favorable shear, especially if any supercells can be sustained. The Slight Risk has been expanded northward to include more of New England, as recent guidance trends show potential for organized severe convection along/ahead much of the length of the front. ...Northern Plains... An upper ridge will persist over much of the Plains today. Even so, a weak mid-level disturbance is forecast to advance eastward from MT across the northern Plains this afternoon/evening on the northern periphery of the upper ridge. This feature should encourage isolated to scattered intense thunderstorm development along/near a warm front extending across parts of ND by late afternoon/early evening. Moderate to strong instability is expected along/near this boundary, aided by steep lapse rates aloft. Modest low-level southerly flow is forecast to gradually veer and strengthen with height through mid/upper levels. This will support sufficient deep-layer shear (30-40 kt) for organized convection, including some supercells initially across western/central ND. These supercells should pose a threat for scattered large hail, some of which may be 2+ inches in diameter given a rather favorable thermodynamic environment forecast. With time this evening, there may be some potential for upscale growth into a small bowing cluster with eastward extent into central/eastern ND. If this mode transition occurs, then the severe/damaging wind threat would likewise increase. Although low-level flow should remain fairly modest, a tornado or two also appears possible, particularly along/near the front where effective SRH should be locally enhanced. ...Upper Midwest... Compared to the northern Plains, there is generally less confidence in overall thunderstorm coverage and development across much of the Upper Midwest through the period. Weak forcing aloft and the persistence of the upper ridge should tend to limit convective development in an otherwise moderately to strongly unstable airmass. Still, any thunderstorms which can develop, perhaps aided by modest low-level warm advection this evening/tonight, could pose an isolated severe hail/wind threat. The Marginal Risk area has been adjusted northward/westward some based on latest guidance trends showing multiple potential zones of isolated strong/severe thunderstorms. ..Gleason/Lyons.. 07/03/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Wed Jul 02 2025 Valid 030100Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MONTANA... ...SUMMARY... Isolated to widely scattered severe thunderstorm gusts remain possible across parts of eastern Oregon into Idaho and Montana this evening. Isolated severe thunderstorms may also occur over portions of the Upper Midwest/Great Lakes. ...Eastern Oregon into the Northern Rockies/High Plains... Convection has developed this afternoon/evening along the western and northern periphery of upper troughing centered over the High Plains. Surface observations and various forecast soundings suggest a very well mixed airmass is present from eastern OR into the northern Rockies/High Plains, with surface temperature/dewpoint spreads of 30-40+ F common. While instability and deep-layer shear are both forecast to remain fairly modest, there may be some loosely organized clusters posing a threat for isolated to scattered severe winds this evening. The greatest concentration of thunderstorms and severe winds may still focus across parts of central/eastern MT over the next several hours, where the Slight Risk has been maintained. See Mesoscale Discussion 1544 for more details on the short-term severe threat across this area. ...Upper Midwest/Great Lakes... Widely scattered thunderstorms should continue across parts the Upper Midwest and Great Lakes this evening, as the glancing influence of upper troughing over Ontario and the northern Great Lakes overspreads this region. Modest low-level flow per area VWPs gradually veers to northwesterly at mid/upper levels, which is supporting around 30-35 kt of deep-layer shear. Occasional thunderstorm organization has been noted with the ongoing activity given a sufficiently unstable airmass, and isolated damaging winds/hail should remain possible for a couple more hours before convection eventually weakens later this evening. ...Great Basin/Southwest... Convection earlier today has largely overturned the airmass across much of NV into western UT. Occasional strong to severe gusts will remain possible with any ongoing/additional convection across the Sierra into the Great Basin and Southwest where low-level lapse rates remain steepened. But, overall severe wind potential is expected to remain rather isolated, with a small Marginal Risk for wind maintained across parts of southern NV and vicinity where low-level lapse rates remain steepened amid 30-40 kt of southerly deep-layer shear. ..Gleason.. 07/03/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Wed Jul 02 2025 Valid 030100Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MONTANA... ...SUMMARY... Isolated to widely scattered severe thunderstorm gusts remain possible across parts of eastern Oregon into Idaho and Montana this evening. Isolated severe thunderstorms may also occur over portions of the Upper Midwest/Great Lakes. ...Eastern Oregon into the Northern Rockies/High Plains... Convection has developed this afternoon/evening along the western and northern periphery of upper troughing centered over the High Plains. Surface observations and various forecast soundings suggest a very well mixed airmass is present from eastern OR into the northern Rockies/High Plains, with surface temperature/dewpoint spreads of 30-40+ F common. While instability and deep-layer shear are both forecast to remain fairly modest, there may be some loosely organized clusters posing a threat for isolated to scattered severe winds this evening. The greatest concentration of thunderstorms and severe winds may still focus across parts of central/eastern MT over the next several hours, where the Slight Risk has been maintained. See Mesoscale Discussion 1544 for more details on the short-term severe threat across this area. ...Upper Midwest/Great Lakes... Widely scattered thunderstorms should continue across parts the Upper Midwest and Great Lakes this evening, as the glancing influence of upper troughing over Ontario and the northern Great Lakes overspreads this region. Modest low-level flow per area VWPs gradually veers to northwesterly at mid/upper levels, which is supporting around 30-35 kt of deep-layer shear. Occasional thunderstorm organization has been noted with the ongoing activity given a sufficiently unstable airmass, and isolated damaging winds/hail should remain possible for a couple more hours before convection eventually weakens later this evening. ...Great Basin/Southwest... Convection earlier today has largely overturned the airmass across much of NV into western UT. Occasional strong to severe gusts will remain possible with any ongoing/additional convection across the Sierra into the Great Basin and Southwest where low-level lapse rates remain steepened. But, overall severe wind potential is expected to remain rather isolated, with a small Marginal Risk for wind maintained across parts of southern NV and vicinity where low-level lapse rates remain steepened amid 30-40 kt of southerly deep-layer shear. ..Gleason.. 07/03/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Wed Jul 02 2025 Valid 030100Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MONTANA... ...SUMMARY... Isolated to widely scattered severe thunderstorm gusts remain possible across parts of eastern Oregon into Idaho and Montana this evening. Isolated severe thunderstorms may also occur over portions of the Upper Midwest/Great Lakes. ...Eastern Oregon into the Northern Rockies/High Plains... Convection has developed this afternoon/evening along the western and northern periphery of upper troughing centered over the High Plains. Surface observations and various forecast soundings suggest a very well mixed airmass is present from eastern OR into the northern Rockies/High Plains, with surface temperature/dewpoint spreads of 30-40+ F common. While instability and deep-layer shear are both forecast to remain fairly modest, there may be some loosely organized clusters posing a threat for isolated to scattered severe winds this evening. The greatest concentration of thunderstorms and severe winds may still focus across parts of central/eastern MT over the next several hours, where the Slight Risk has been maintained. See Mesoscale Discussion 1544 for more details on the short-term severe threat across this area. ...Upper Midwest/Great Lakes... Widely scattered thunderstorms should continue across parts the Upper Midwest and Great Lakes this evening, as the glancing influence of upper troughing over Ontario and the northern Great Lakes overspreads this region. Modest low-level flow per area VWPs gradually veers to northwesterly at mid/upper levels, which is supporting around 30-35 kt of deep-layer shear. Occasional thunderstorm organization has been noted with the ongoing activity given a sufficiently unstable airmass, and isolated damaging winds/hail should remain possible for a couple more hours before convection eventually weakens later this evening. ...Great Basin/Southwest... Convection earlier today has largely overturned the airmass across much of NV into western UT. Occasional strong to severe gusts will remain possible with any ongoing/additional convection across the Sierra into the Great Basin and Southwest where low-level lapse rates remain steepened. But, overall severe wind potential is expected to remain rather isolated, with a small Marginal Risk for wind maintained across parts of southern NV and vicinity where low-level lapse rates remain steepened amid 30-40 kt of southerly deep-layer shear. ..Gleason.. 07/03/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Wed Jul 02 2025 Valid 030100Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MONTANA... ...SUMMARY... Isolated to widely scattered severe thunderstorm gusts remain possible across parts of eastern Oregon into Idaho and Montana this evening. Isolated severe thunderstorms may also occur over portions of the Upper Midwest/Great Lakes. ...Eastern Oregon into the Northern Rockies/High Plains... Convection has developed this afternoon/evening along the western and northern periphery of upper troughing centered over the High Plains. Surface observations and various forecast soundings suggest a very well mixed airmass is present from eastern OR into the northern Rockies/High Plains, with surface temperature/dewpoint spreads of 30-40+ F common. While instability and deep-layer shear are both forecast to remain fairly modest, there may be some loosely organized clusters posing a threat for isolated to scattered severe winds this evening. The greatest concentration of thunderstorms and severe winds may still focus across parts of central/eastern MT over the next several hours, where the Slight Risk has been maintained. See Mesoscale Discussion 1544 for more details on the short-term severe threat across this area. ...Upper Midwest/Great Lakes... Widely scattered thunderstorms should continue across parts the Upper Midwest and Great Lakes this evening, as the glancing influence of upper troughing over Ontario and the northern Great Lakes overspreads this region. Modest low-level flow per area VWPs gradually veers to northwesterly at mid/upper levels, which is supporting around 30-35 kt of deep-layer shear. Occasional thunderstorm organization has been noted with the ongoing activity given a sufficiently unstable airmass, and isolated damaging winds/hail should remain possible for a couple more hours before convection eventually weakens later this evening. ...Great Basin/Southwest... Convection earlier today has largely overturned the airmass across much of NV into western UT. Occasional strong to severe gusts will remain possible with any ongoing/additional convection across the Sierra into the Great Basin and Southwest where low-level lapse rates remain steepened. But, overall severe wind potential is expected to remain rather isolated, with a small Marginal Risk for wind maintained across parts of southern NV and vicinity where low-level lapse rates remain steepened amid 30-40 kt of southerly deep-layer shear. ..Gleason.. 07/03/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 PM CDT Wed Jul 02 2025 Valid 030100Z - 031200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MONTANA... ...SUMMARY... Isolated to widely scattered severe thunderstorm gusts remain possible across parts of eastern Oregon into Idaho and Montana this evening. Isolated severe thunderstorms may also occur over portions of the Upper Midwest/Great Lakes. ...Eastern Oregon into the Northern Rockies/High Plains... Convection has developed this afternoon/evening along the western and northern periphery of upper troughing centered over the High Plains. Surface observations and various forecast soundings suggest a very well mixed airmass is present from eastern OR into the northern Rockies/High Plains, with surface temperature/dewpoint spreads of 30-40+ F common. While instability and deep-layer shear are both forecast to remain fairly modest, there may be some loosely organized clusters posing a threat for isolated to scattered severe winds this evening. The greatest concentration of thunderstorms and severe winds may still focus across parts of central/eastern MT over the next several hours, where the Slight Risk has been maintained. See Mesoscale Discussion 1544 for more details on the short-term severe threat across this area. ...Upper Midwest/Great Lakes... Widely scattered thunderstorms should continue across parts the Upper Midwest and Great Lakes this evening, as the glancing influence of upper troughing over Ontario and the northern Great Lakes overspreads this region. Modest low-level flow per area VWPs gradually veers to northwesterly at mid/upper levels, which is supporting around 30-35 kt of deep-layer shear. Occasional thunderstorm organization has been noted with the ongoing activity given a sufficiently unstable airmass, and isolated damaging winds/hail should remain possible for a couple more hours before convection eventually weakens later this evening. ...Great Basin/Southwest... Convection earlier today has largely overturned the airmass across much of NV into western UT. Occasional strong to severe gusts will remain possible with any ongoing/additional convection across the Sierra into the Great Basin and Southwest where low-level lapse rates remain steepened. But, overall severe wind potential is expected to remain rather isolated, with a small Marginal Risk for wind maintained across parts of southern NV and vicinity where low-level lapse rates remain steepened amid 30-40 kt of southerly deep-layer shear. ..Gleason.. 07/03/2025 Read more

MD 1544 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PARTS OF NORTH-CENTRAL AND NORTHEAST MONTANA
Mesoscale Discussion 1544 NWS Storm Prediction Center Norman OK 0747 PM CDT Wed Jul 02 2025 Areas affected...Parts of north-central and northeast Montana Concerning...Severe potential...Watch possible Valid 030047Z - 030215Z Probability of Watch Issuance...40 percent SUMMARY...The area is still being monitored for an increase in severe-gust/outflow potential. The need for a watch is still uncertain. DISCUSSION...A cluster of disorganized convection with transient/embedded deeper cores is evolving northeast of Lewistown MT, where a 36 kt gust was recently measured. As this activity (and additional storms farther east along a north/south-oriented wind shift) continue east-northeastward, very steep low-level lapse rates may promote sporadic severe outflow winds. However, the combination of modest buoyancy and deep-layer shear in the vicinity of the convection northeast of Lewistown casts uncertainty on the potential for an organized cluster to evolve. An elongated mid/upper-level hodograph sampled by the GGW VWP may favor some convective organization with the storms immediately east of Glasgow MT, though limited residence time in the weakly unstable air mass also limits confidence in severe coverage/potential. Overall, it is still unclear if the scenario will warrant a watch, though trends are being monitored. ..Weinman/Guyer.. 07/03/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BYZ...GGW...TFX... LAT...LON 47100634 46840747 46900891 47240951 47670971 48130960 48700923 49080852 49080535 48580510 47620559 47100634 MOST PROBABLE PEAK WIND GUST...65-80 MPH Read more

MD 1543 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF THE UPPER MIDWEST
Mesoscale Discussion 1543 NWS Storm Prediction Center Norman OK 0550 PM CDT Wed Jul 02 2025 Areas affected...Parts of the Upper Midwest Concerning...Severe potential...Watch unlikely Valid 022250Z - 030015Z Probability of Watch Issuance...20 percent SUMMARY...Isolated instances of marginally severe hail and locally strong gusts will be possible during the next few hours. DISCUSSION...Isolated thunderstorms are initiating along a weak low-level moisture gradient and wind shift extending southeastward from southeast MN into far southwest WI -- aided by a midlevel speed max approaching the area (evident in water-vapor imagery). An elongated/straight hodograph (around 30 kt of effective shear) and sufficient surface-based instability along this corridor may promote brief/transient convective organization over the next few hours. Given an expected cellular mode amid the elongated/straight hodograph and modestly steep lapse rates, isolated instances of marginally severe hail will be possible (along with locally strong gusts). The overall threat is expected to remain too localized and transient for a watch. ..Weinman/Guyer.. 07/02/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...MKX...DVN...ARX...MPX...DMX... LAT...LON 43439360 43879412 44359423 44839385 44879299 44649231 43539014 42878994 42359041 42469139 43439360 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN Read more

No watches are valid as of Wed Jul 2 23:59:01 UTC 2025.