Severe Storms

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Jul 07 2025 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING FROM NORTHEAST COLORADO INTO PARTS OF NEBRASKA AND SOUTH DAKOTA.... ...SUMMARY... Scattered severe storms are likely across the central into northern Plains. Severe wind gusts and large hail are the main threats. Isolated damaging winds are also possible across parts of the Lower Great Lakes, Ohio/Tennessee River Valleys, and the Northeast. ...SD/NE/KS/CO... A complex evolution of convection is expected this afternoon and evening across the central Plains. One line/cluster of thunderstorms is expected to develop from the showers across SD. Continued daytime heating will eventually lead to intensification and organization of storms building southeastward into NE and western IA. These storms will pose a risk of large hail and damaging winds. Farther southwest, storms are expected to develop and spread eastward across southeast WY and northeast CO (similar to yesterday) and eventually track into western NE/KS. These storms will also pose risk of damaging winds and hail through the early evening. It appears likely that these two convective regimes will congeal during the evening, with more of a southward push into KS and eventually northern OK late tonight, although the severe risk by that time is uncertain. ...OH to ME... A warm/humid air mass is present today from OH northeastward across parts of NY/PA and northern New England. Widely scattered afternoon thunderstorms are expected along this entire corridor. Strong daytime heating will result in steep low-level lapse rates, with sufficient mid-level westerly flow to aid in gusty/damaging wind gusts. ..Hart/Karstens.. 07/07/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Jul 07 2025 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING FROM NORTHEAST COLORADO INTO PARTS OF NEBRASKA AND SOUTH DAKOTA.... ...SUMMARY... Scattered severe storms are likely across the central into northern Plains. Severe wind gusts and large hail are the main threats. Isolated damaging winds are also possible across parts of the Lower Great Lakes, Ohio/Tennessee River Valleys, and the Northeast. ...SD/NE/KS/CO... A complex evolution of convection is expected this afternoon and evening across the central Plains. One line/cluster of thunderstorms is expected to develop from the showers across SD. Continued daytime heating will eventually lead to intensification and organization of storms building southeastward into NE and western IA. These storms will pose a risk of large hail and damaging winds. Farther southwest, storms are expected to develop and spread eastward across southeast WY and northeast CO (similar to yesterday) and eventually track into western NE/KS. These storms will also pose risk of damaging winds and hail through the early evening. It appears likely that these two convective regimes will congeal during the evening, with more of a southward push into KS and eventually northern OK late tonight, although the severe risk by that time is uncertain. ...OH to ME... A warm/humid air mass is present today from OH northeastward across parts of NY/PA and northern New England. Widely scattered afternoon thunderstorms are expected along this entire corridor. Strong daytime heating will result in steep low-level lapse rates, with sufficient mid-level westerly flow to aid in gusty/damaging wind gusts. ..Hart/Karstens.. 07/07/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Jul 07 2025 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING FROM NORTHEAST COLORADO INTO PARTS OF NEBRASKA AND SOUTH DAKOTA.... ...SUMMARY... Scattered severe storms are likely across the central into northern Plains. Severe wind gusts and large hail are the main threats. Isolated damaging winds are also possible across parts of the Lower Great Lakes, Ohio/Tennessee River Valleys, and the Northeast. ...SD/NE/KS/CO... A complex evolution of convection is expected this afternoon and evening across the central Plains. One line/cluster of thunderstorms is expected to develop from the showers across SD. Continued daytime heating will eventually lead to intensification and organization of storms building southeastward into NE and western IA. These storms will pose a risk of large hail and damaging winds. Farther southwest, storms are expected to develop and spread eastward across southeast WY and northeast CO (similar to yesterday) and eventually track into western NE/KS. These storms will also pose risk of damaging winds and hail through the early evening. It appears likely that these two convective regimes will congeal during the evening, with more of a southward push into KS and eventually northern OK late tonight, although the severe risk by that time is uncertain. ...OH to ME... A warm/humid air mass is present today from OH northeastward across parts of NY/PA and northern New England. Widely scattered afternoon thunderstorms are expected along this entire corridor. Strong daytime heating will result in steep low-level lapse rates, with sufficient mid-level westerly flow to aid in gusty/damaging wind gusts. ..Hart/Karstens.. 07/07/2025 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1124 AM CDT Mon Jul 07 2025 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING FROM NORTHEAST COLORADO INTO PARTS OF NEBRASKA AND SOUTH DAKOTA.... ...SUMMARY... Scattered severe storms are likely across the central into northern Plains. Severe wind gusts and large hail are the main threats. Isolated damaging winds are also possible across parts of the Lower Great Lakes, Ohio/Tennessee River Valleys, and the Northeast. ...SD/NE/KS/CO... A complex evolution of convection is expected this afternoon and evening across the central Plains. One line/cluster of thunderstorms is expected to develop from the showers across SD. Continued daytime heating will eventually lead to intensification and organization of storms building southeastward into NE and western IA. These storms will pose a risk of large hail and damaging winds. Farther southwest, storms are expected to develop and spread eastward across southeast WY and northeast CO (similar to yesterday) and eventually track into western NE/KS. These storms will also pose risk of damaging winds and hail through the early evening. It appears likely that these two convective regimes will congeal during the evening, with more of a southward push into KS and eventually northern OK late tonight, although the severe risk by that time is uncertain. ...OH to ME... A warm/humid air mass is present today from OH northeastward across parts of NY/PA and northern New England. Widely scattered afternoon thunderstorms are expected along this entire corridor. Strong daytime heating will result in steep low-level lapse rates, with sufficient mid-level westerly flow to aid in gusty/damaging wind gusts. ..Hart/Karstens.. 07/07/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0728 AM CDT Mon Jul 07 2025 Valid 071300Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe storms are likely across the central into northern Plains. Severe wind gusts and large hail are the main threats. Isolated damaging winds are also possible across parts of the Lower Great Lakes, Ohio River Valley, and the Northeast. ...Central High Plains into the northern Plains... A shortwave trough within westerly mid-level flow will move east/southeast across the central/northern Plains through tonight, along the periphery of a meridionally-expanding upper-level ridge. Steep mid-level lapse rates will expand east across the central Plains, above a moist boundary layer (generally 60s F dew points) and contributing to strong instability this afternoon with MLCAPE at or above 2500 J/kg. Thunderstorms are expected to develop this afternoon across the higher terrain over the central High Plains, and move east through this evening. Initial supercells will be capable of large to very large hail, though transitioning into one or more MCSs with an increase in damaging wind potential, including significant severe gusts. Thunderstorms are also expected to develop/re-intensify, across central/eastern SD along a surface trough, with upscale growth into an MCS capable of severe winds as it moves east, potentially into southwest MN this evening before weakening. Given expectations for greater coverage based on latest hi-res guidance, the Level 3/Enhanced Risk has been extended north across eastern SD/southwest MN based on higher (30%) severe wind probabilities. ...Upper Ohio River Valley, Lower Great Lakes, and the Northeast... A cold Front will move east today, and inpinge upon a moist (PW at or above 1.75 in) and moderately unstable air mass, with afternoon MLCAPE ranging from near 1000 J/kg across ME to 1500-2000 J/kg over the upper OH Valley. The area will located along the southern fringe of modest southwest mid-level flow, sufficient for some degree of updraft organization. Scattered multicell/clusters of thunderstorms developing this afternoon will pose a risk for strong/damaging gusts with isolated stronger storms. ...Lower Ohio Valley into Ozarks... Scattered thunderstorms this afternoon developing in the vicinity of a southward-advancing cold front will have the potential for isolated wet microbursts within a moist (PW 1.75 to over 2 inches) air mass. Weak cloud-bearing layer shear should limit organization, but overall storm coverage should be sufficient for isolated damaging gusts. ..Bunting/Marsh.. 07/07/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0728 AM CDT Mon Jul 07 2025 Valid 071300Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe storms are likely across the central into northern Plains. Severe wind gusts and large hail are the main threats. Isolated damaging winds are also possible across parts of the Lower Great Lakes, Ohio River Valley, and the Northeast. ...Central High Plains into the northern Plains... A shortwave trough within westerly mid-level flow will move east/southeast across the central/northern Plains through tonight, along the periphery of a meridionally-expanding upper-level ridge. Steep mid-level lapse rates will expand east across the central Plains, above a moist boundary layer (generally 60s F dew points) and contributing to strong instability this afternoon with MLCAPE at or above 2500 J/kg. Thunderstorms are expected to develop this afternoon across the higher terrain over the central High Plains, and move east through this evening. Initial supercells will be capable of large to very large hail, though transitioning into one or more MCSs with an increase in damaging wind potential, including significant severe gusts. Thunderstorms are also expected to develop/re-intensify, across central/eastern SD along a surface trough, with upscale growth into an MCS capable of severe winds as it moves east, potentially into southwest MN this evening before weakening. Given expectations for greater coverage based on latest hi-res guidance, the Level 3/Enhanced Risk has been extended north across eastern SD/southwest MN based on higher (30%) severe wind probabilities. ...Upper Ohio River Valley, Lower Great Lakes, and the Northeast... A cold Front will move east today, and inpinge upon a moist (PW at or above 1.75 in) and moderately unstable air mass, with afternoon MLCAPE ranging from near 1000 J/kg across ME to 1500-2000 J/kg over the upper OH Valley. The area will located along the southern fringe of modest southwest mid-level flow, sufficient for some degree of updraft organization. Scattered multicell/clusters of thunderstorms developing this afternoon will pose a risk for strong/damaging gusts with isolated stronger storms. ...Lower Ohio Valley into Ozarks... Scattered thunderstorms this afternoon developing in the vicinity of a southward-advancing cold front will have the potential for isolated wet microbursts within a moist (PW 1.75 to over 2 inches) air mass. Weak cloud-bearing layer shear should limit organization, but overall storm coverage should be sufficient for isolated damaging gusts. ..Bunting/Marsh.. 07/07/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0728 AM CDT Mon Jul 07 2025 Valid 071300Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe storms are likely across the central into northern Plains. Severe wind gusts and large hail are the main threats. Isolated damaging winds are also possible across parts of the Lower Great Lakes, Ohio River Valley, and the Northeast. ...Central High Plains into the northern Plains... A shortwave trough within westerly mid-level flow will move east/southeast across the central/northern Plains through tonight, along the periphery of a meridionally-expanding upper-level ridge. Steep mid-level lapse rates will expand east across the central Plains, above a moist boundary layer (generally 60s F dew points) and contributing to strong instability this afternoon with MLCAPE at or above 2500 J/kg. Thunderstorms are expected to develop this afternoon across the higher terrain over the central High Plains, and move east through this evening. Initial supercells will be capable of large to very large hail, though transitioning into one or more MCSs with an increase in damaging wind potential, including significant severe gusts. Thunderstorms are also expected to develop/re-intensify, across central/eastern SD along a surface trough, with upscale growth into an MCS capable of severe winds as it moves east, potentially into southwest MN this evening before weakening. Given expectations for greater coverage based on latest hi-res guidance, the Level 3/Enhanced Risk has been extended north across eastern SD/southwest MN based on higher (30%) severe wind probabilities. ...Upper Ohio River Valley, Lower Great Lakes, and the Northeast... A cold Front will move east today, and inpinge upon a moist (PW at or above 1.75 in) and moderately unstable air mass, with afternoon MLCAPE ranging from near 1000 J/kg across ME to 1500-2000 J/kg over the upper OH Valley. The area will located along the southern fringe of modest southwest mid-level flow, sufficient for some degree of updraft organization. Scattered multicell/clusters of thunderstorms developing this afternoon will pose a risk for strong/damaging gusts with isolated stronger storms. ...Lower Ohio Valley into Ozarks... Scattered thunderstorms this afternoon developing in the vicinity of a southward-advancing cold front will have the potential for isolated wet microbursts within a moist (PW 1.75 to over 2 inches) air mass. Weak cloud-bearing layer shear should limit organization, but overall storm coverage should be sufficient for isolated damaging gusts. ..Bunting/Marsh.. 07/07/2025 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0728 AM CDT Mon Jul 07 2025 Valid 071300Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL AND NORTHERN PLAINS... ...SUMMARY... Scattered severe storms are likely across the central into northern Plains. Severe wind gusts and large hail are the main threats. Isolated damaging winds are also possible across parts of the Lower Great Lakes, Ohio River Valley, and the Northeast. ...Central High Plains into the northern Plains... A shortwave trough within westerly mid-level flow will move east/southeast across the central/northern Plains through tonight, along the periphery of a meridionally-expanding upper-level ridge. Steep mid-level lapse rates will expand east across the central Plains, above a moist boundary layer (generally 60s F dew points) and contributing to strong instability this afternoon with MLCAPE at or above 2500 J/kg. Thunderstorms are expected to develop this afternoon across the higher terrain over the central High Plains, and move east through this evening. Initial supercells will be capable of large to very large hail, though transitioning into one or more MCSs with an increase in damaging wind potential, including significant severe gusts. Thunderstorms are also expected to develop/re-intensify, across central/eastern SD along a surface trough, with upscale growth into an MCS capable of severe winds as it moves east, potentially into southwest MN this evening before weakening. Given expectations for greater coverage based on latest hi-res guidance, the Level 3/Enhanced Risk has been extended north across eastern SD/southwest MN based on higher (30%) severe wind probabilities. ...Upper Ohio River Valley, Lower Great Lakes, and the Northeast... A cold Front will move east today, and inpinge upon a moist (PW at or above 1.75 in) and moderately unstable air mass, with afternoon MLCAPE ranging from near 1000 J/kg across ME to 1500-2000 J/kg over the upper OH Valley. The area will located along the southern fringe of modest southwest mid-level flow, sufficient for some degree of updraft organization. Scattered multicell/clusters of thunderstorms developing this afternoon will pose a risk for strong/damaging gusts with isolated stronger storms. ...Lower Ohio Valley into Ozarks... Scattered thunderstorms this afternoon developing in the vicinity of a southward-advancing cold front will have the potential for isolated wet microbursts within a moist (PW 1.75 to over 2 inches) air mass. Weak cloud-bearing layer shear should limit organization, but overall storm coverage should be sufficient for isolated damaging gusts. ..Bunting/Marsh.. 07/07/2025 Read more

MD 1588 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR FAR NORTHEAST WYOMING...FAR SOUTHEAST MONTANA...AND WESTERN SOUTH DAKOTA
Mesoscale Discussion 1588 NWS Storm Prediction Center Norman OK 0412 AM CDT Mon Jul 07 2025 Areas affected...far northeast Wyoming...far southeast Montana...and western South Dakota Concerning...Severe potential...Watch unlikely Valid 070912Z - 071115Z Probability of Watch Issuance...20 percent SUMMARY...Thunderstorms should continue this morning. Hail and gusty winds may be possible with the strongest storms. Currently, a watch is not anticipated for this threat. DISCUSSION...Elevated thunderstorms are ongoing / redeveloping this morning across far northeast Wyoming and western South Dakota. These storms appear to be rooted between 850 and 700 millibars and are likely driven by modest warm-air advection within this layer per model forecast soundings across the region. The overall environment is unstable with most-unstable CAPE between 1000-1500 J/kg. However, effective-layer shear is quite variable across the area, with better shear to the north and to the south of the ongoing thunderstorms. That said, effective-layer shear between 25-30 knots is sufficient to support strong multicells or even transient supercellular characteristics. Given the degree of instability and at least modest effective-layer shear, isolated hail and perhaps strong wind gusts cannot be ruled out with the stronger thunderstorm updrafts. However, widespread organized severe potential is not anticipated and thus a watch is not expected. Some CAM-based guidance does indicate the potential for ongoing thunderstorms to eventually coalesce into a small organized MCS later this morning. Should evidence of this organization start to materialize, the potential for a watch later this morning would increase accordingly. ..Marsh/Bunting.. 07/07/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...ABR...UNR...BYZ... LAT...LON 44090536 44530586 45040550 45350454 45630349 45580231 45230132 44520099 43880102 43440139 43220220 43420333 43710446 44090536 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0342 AM CDT Mon Jul 07 2025 Valid 101200Z - 151200Z ...DISCUSSION... The Southwest upper ridge will gradually flatten as a more progressive mid-level flow regime becomes established over the northern CONUS later this week into early next week. Multiple pronounced mid-level troughs, with cooler temperatures aloft, will traverse the north-central U.S. and overspread rich low-level moisture. Strong buoyancy will precede these troughs, and upon lifting of this unstable airmass, at least scattered organized thunderstorm development should ensue, with multiple rounds of strong to severe storms possible. ...Day 4 (Thursday) - Northern Plains... The first in a series of mid-level troughs will eject into the northern Plains on Day 4/Thursday, encouraging surface lee troughing across the central and northern Plains. Dewpoints into the 70s F, beneath 8+ C/km mid-level lapse rates, will support strong to locally extreme instability by afternoon peak heating. The ejection of the upper trough will provide enough upper support for scattered thunderstorm development. Increasing westerly flow with height will result in straight, elongated hodographs. Supercells should be the main mode of convection, at least initially, with severe wind and hail the primary threats. ...Days 5-6 (Friday-Saturday) - Midwest toward the Great Lakes... The main mid-level trough will continue to slowly approach the Upper MS Valley as a preceding mid-level impulse continues to advance eastward. Potential exists for renewed thunderstorm development for portions of the Upper MS Valley and Midwest on Friday, spreading east with upper trough advancement toward the Great Lakes on Saturday. Rich low-level moisture beneath steep mid-level lapse rates will promote strong instability in the warm sector, amid modest vertical wind shear. Somewhere in this region, strong to severe storms are likely, with severe wind/hail the main concerns on both Friday and Saturday. The timing and location of thunderstorm initiation will be highly dependent on the position of remnant outflow boundaries from storms during previous days. Such details are quite challenging to point out this far in advance, precluding severe probabilities at this time, though probabilities will likely be needed in future outlooks. ...Days 7-8 (Sunday-Monday) - Upper Mississippi Valley... The next in a series of mid-level troughs will traverse the north-central CONUS toward the end of the period. Medium-range guidance consensus depicts extreme instability (i.e. well over 4000 J/kg MLCAPE) preceding this trough, along with strong enough westerly mid-level flow and accompanying vertical wind shear. As such, another episode of organized severe storms is possible in the Sunday/Monday time-frame. However, given the seasonal weak forcing associated with this second low-amplitude trough, run-to-run guidance consistency is desired before severe probabilities are delineated. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0342 AM CDT Mon Jul 07 2025 Valid 101200Z - 151200Z ...DISCUSSION... The Southwest upper ridge will gradually flatten as a more progressive mid-level flow regime becomes established over the northern CONUS later this week into early next week. Multiple pronounced mid-level troughs, with cooler temperatures aloft, will traverse the north-central U.S. and overspread rich low-level moisture. Strong buoyancy will precede these troughs, and upon lifting of this unstable airmass, at least scattered organized thunderstorm development should ensue, with multiple rounds of strong to severe storms possible. ...Day 4 (Thursday) - Northern Plains... The first in a series of mid-level troughs will eject into the northern Plains on Day 4/Thursday, encouraging surface lee troughing across the central and northern Plains. Dewpoints into the 70s F, beneath 8+ C/km mid-level lapse rates, will support strong to locally extreme instability by afternoon peak heating. The ejection of the upper trough will provide enough upper support for scattered thunderstorm development. Increasing westerly flow with height will result in straight, elongated hodographs. Supercells should be the main mode of convection, at least initially, with severe wind and hail the primary threats. ...Days 5-6 (Friday-Saturday) - Midwest toward the Great Lakes... The main mid-level trough will continue to slowly approach the Upper MS Valley as a preceding mid-level impulse continues to advance eastward. Potential exists for renewed thunderstorm development for portions of the Upper MS Valley and Midwest on Friday, spreading east with upper trough advancement toward the Great Lakes on Saturday. Rich low-level moisture beneath steep mid-level lapse rates will promote strong instability in the warm sector, amid modest vertical wind shear. Somewhere in this region, strong to severe storms are likely, with severe wind/hail the main concerns on both Friday and Saturday. The timing and location of thunderstorm initiation will be highly dependent on the position of remnant outflow boundaries from storms during previous days. Such details are quite challenging to point out this far in advance, precluding severe probabilities at this time, though probabilities will likely be needed in future outlooks. ...Days 7-8 (Sunday-Monday) - Upper Mississippi Valley... The next in a series of mid-level troughs will traverse the north-central CONUS toward the end of the period. Medium-range guidance consensus depicts extreme instability (i.e. well over 4000 J/kg MLCAPE) preceding this trough, along with strong enough westerly mid-level flow and accompanying vertical wind shear. As such, another episode of organized severe storms is possible in the Sunday/Monday time-frame. However, given the seasonal weak forcing associated with this second low-amplitude trough, run-to-run guidance consistency is desired before severe probabilities are delineated. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0342 AM CDT Mon Jul 07 2025 Valid 101200Z - 151200Z ...DISCUSSION... The Southwest upper ridge will gradually flatten as a more progressive mid-level flow regime becomes established over the northern CONUS later this week into early next week. Multiple pronounced mid-level troughs, with cooler temperatures aloft, will traverse the north-central U.S. and overspread rich low-level moisture. Strong buoyancy will precede these troughs, and upon lifting of this unstable airmass, at least scattered organized thunderstorm development should ensue, with multiple rounds of strong to severe storms possible. ...Day 4 (Thursday) - Northern Plains... The first in a series of mid-level troughs will eject into the northern Plains on Day 4/Thursday, encouraging surface lee troughing across the central and northern Plains. Dewpoints into the 70s F, beneath 8+ C/km mid-level lapse rates, will support strong to locally extreme instability by afternoon peak heating. The ejection of the upper trough will provide enough upper support for scattered thunderstorm development. Increasing westerly flow with height will result in straight, elongated hodographs. Supercells should be the main mode of convection, at least initially, with severe wind and hail the primary threats. ...Days 5-6 (Friday-Saturday) - Midwest toward the Great Lakes... The main mid-level trough will continue to slowly approach the Upper MS Valley as a preceding mid-level impulse continues to advance eastward. Potential exists for renewed thunderstorm development for portions of the Upper MS Valley and Midwest on Friday, spreading east with upper trough advancement toward the Great Lakes on Saturday. Rich low-level moisture beneath steep mid-level lapse rates will promote strong instability in the warm sector, amid modest vertical wind shear. Somewhere in this region, strong to severe storms are likely, with severe wind/hail the main concerns on both Friday and Saturday. The timing and location of thunderstorm initiation will be highly dependent on the position of remnant outflow boundaries from storms during previous days. Such details are quite challenging to point out this far in advance, precluding severe probabilities at this time, though probabilities will likely be needed in future outlooks. ...Days 7-8 (Sunday-Monday) - Upper Mississippi Valley... The next in a series of mid-level troughs will traverse the north-central CONUS toward the end of the period. Medium-range guidance consensus depicts extreme instability (i.e. well over 4000 J/kg MLCAPE) preceding this trough, along with strong enough westerly mid-level flow and accompanying vertical wind shear. As such, another episode of organized severe storms is possible in the Sunday/Monday time-frame. However, given the seasonal weak forcing associated with this second low-amplitude trough, run-to-run guidance consistency is desired before severe probabilities are delineated. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0342 AM CDT Mon Jul 07 2025 Valid 101200Z - 151200Z ...DISCUSSION... The Southwest upper ridge will gradually flatten as a more progressive mid-level flow regime becomes established over the northern CONUS later this week into early next week. Multiple pronounced mid-level troughs, with cooler temperatures aloft, will traverse the north-central U.S. and overspread rich low-level moisture. Strong buoyancy will precede these troughs, and upon lifting of this unstable airmass, at least scattered organized thunderstorm development should ensue, with multiple rounds of strong to severe storms possible. ...Day 4 (Thursday) - Northern Plains... The first in a series of mid-level troughs will eject into the northern Plains on Day 4/Thursday, encouraging surface lee troughing across the central and northern Plains. Dewpoints into the 70s F, beneath 8+ C/km mid-level lapse rates, will support strong to locally extreme instability by afternoon peak heating. The ejection of the upper trough will provide enough upper support for scattered thunderstorm development. Increasing westerly flow with height will result in straight, elongated hodographs. Supercells should be the main mode of convection, at least initially, with severe wind and hail the primary threats. ...Days 5-6 (Friday-Saturday) - Midwest toward the Great Lakes... The main mid-level trough will continue to slowly approach the Upper MS Valley as a preceding mid-level impulse continues to advance eastward. Potential exists for renewed thunderstorm development for portions of the Upper MS Valley and Midwest on Friday, spreading east with upper trough advancement toward the Great Lakes on Saturday. Rich low-level moisture beneath steep mid-level lapse rates will promote strong instability in the warm sector, amid modest vertical wind shear. Somewhere in this region, strong to severe storms are likely, with severe wind/hail the main concerns on both Friday and Saturday. The timing and location of thunderstorm initiation will be highly dependent on the position of remnant outflow boundaries from storms during previous days. Such details are quite challenging to point out this far in advance, precluding severe probabilities at this time, though probabilities will likely be needed in future outlooks. ...Days 7-8 (Sunday-Monday) - Upper Mississippi Valley... The next in a series of mid-level troughs will traverse the north-central CONUS toward the end of the period. Medium-range guidance consensus depicts extreme instability (i.e. well over 4000 J/kg MLCAPE) preceding this trough, along with strong enough westerly mid-level flow and accompanying vertical wind shear. As such, another episode of organized severe storms is possible in the Sunday/Monday time-frame. However, given the seasonal weak forcing associated with this second low-amplitude trough, run-to-run guidance consistency is desired before severe probabilities are delineated. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0342 AM CDT Mon Jul 07 2025 Valid 101200Z - 151200Z ...DISCUSSION... The Southwest upper ridge will gradually flatten as a more progressive mid-level flow regime becomes established over the northern CONUS later this week into early next week. Multiple pronounced mid-level troughs, with cooler temperatures aloft, will traverse the north-central U.S. and overspread rich low-level moisture. Strong buoyancy will precede these troughs, and upon lifting of this unstable airmass, at least scattered organized thunderstorm development should ensue, with multiple rounds of strong to severe storms possible. ...Day 4 (Thursday) - Northern Plains... The first in a series of mid-level troughs will eject into the northern Plains on Day 4/Thursday, encouraging surface lee troughing across the central and northern Plains. Dewpoints into the 70s F, beneath 8+ C/km mid-level lapse rates, will support strong to locally extreme instability by afternoon peak heating. The ejection of the upper trough will provide enough upper support for scattered thunderstorm development. Increasing westerly flow with height will result in straight, elongated hodographs. Supercells should be the main mode of convection, at least initially, with severe wind and hail the primary threats. ...Days 5-6 (Friday-Saturday) - Midwest toward the Great Lakes... The main mid-level trough will continue to slowly approach the Upper MS Valley as a preceding mid-level impulse continues to advance eastward. Potential exists for renewed thunderstorm development for portions of the Upper MS Valley and Midwest on Friday, spreading east with upper trough advancement toward the Great Lakes on Saturday. Rich low-level moisture beneath steep mid-level lapse rates will promote strong instability in the warm sector, amid modest vertical wind shear. Somewhere in this region, strong to severe storms are likely, with severe wind/hail the main concerns on both Friday and Saturday. The timing and location of thunderstorm initiation will be highly dependent on the position of remnant outflow boundaries from storms during previous days. Such details are quite challenging to point out this far in advance, precluding severe probabilities at this time, though probabilities will likely be needed in future outlooks. ...Days 7-8 (Sunday-Monday) - Upper Mississippi Valley... The next in a series of mid-level troughs will traverse the north-central CONUS toward the end of the period. Medium-range guidance consensus depicts extreme instability (i.e. well over 4000 J/kg MLCAPE) preceding this trough, along with strong enough westerly mid-level flow and accompanying vertical wind shear. As such, another episode of organized severe storms is possible in the Sunday/Monday time-frame. However, given the seasonal weak forcing associated with this second low-amplitude trough, run-to-run guidance consistency is desired before severe probabilities are delineated. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0342 AM CDT Mon Jul 07 2025 Valid 101200Z - 151200Z ...DISCUSSION... The Southwest upper ridge will gradually flatten as a more progressive mid-level flow regime becomes established over the northern CONUS later this week into early next week. Multiple pronounced mid-level troughs, with cooler temperatures aloft, will traverse the north-central U.S. and overspread rich low-level moisture. Strong buoyancy will precede these troughs, and upon lifting of this unstable airmass, at least scattered organized thunderstorm development should ensue, with multiple rounds of strong to severe storms possible. ...Day 4 (Thursday) - Northern Plains... The first in a series of mid-level troughs will eject into the northern Plains on Day 4/Thursday, encouraging surface lee troughing across the central and northern Plains. Dewpoints into the 70s F, beneath 8+ C/km mid-level lapse rates, will support strong to locally extreme instability by afternoon peak heating. The ejection of the upper trough will provide enough upper support for scattered thunderstorm development. Increasing westerly flow with height will result in straight, elongated hodographs. Supercells should be the main mode of convection, at least initially, with severe wind and hail the primary threats. ...Days 5-6 (Friday-Saturday) - Midwest toward the Great Lakes... The main mid-level trough will continue to slowly approach the Upper MS Valley as a preceding mid-level impulse continues to advance eastward. Potential exists for renewed thunderstorm development for portions of the Upper MS Valley and Midwest on Friday, spreading east with upper trough advancement toward the Great Lakes on Saturday. Rich low-level moisture beneath steep mid-level lapse rates will promote strong instability in the warm sector, amid modest vertical wind shear. Somewhere in this region, strong to severe storms are likely, with severe wind/hail the main concerns on both Friday and Saturday. The timing and location of thunderstorm initiation will be highly dependent on the position of remnant outflow boundaries from storms during previous days. Such details are quite challenging to point out this far in advance, precluding severe probabilities at this time, though probabilities will likely be needed in future outlooks. ...Days 7-8 (Sunday-Monday) - Upper Mississippi Valley... The next in a series of mid-level troughs will traverse the north-central CONUS toward the end of the period. Medium-range guidance consensus depicts extreme instability (i.e. well over 4000 J/kg MLCAPE) preceding this trough, along with strong enough westerly mid-level flow and accompanying vertical wind shear. As such, another episode of organized severe storms is possible in the Sunday/Monday time-frame. However, given the seasonal weak forcing associated with this second low-amplitude trough, run-to-run guidance consistency is desired before severe probabilities are delineated. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0342 AM CDT Mon Jul 07 2025 Valid 101200Z - 151200Z ...DISCUSSION... The Southwest upper ridge will gradually flatten as a more progressive mid-level flow regime becomes established over the northern CONUS later this week into early next week. Multiple pronounced mid-level troughs, with cooler temperatures aloft, will traverse the north-central U.S. and overspread rich low-level moisture. Strong buoyancy will precede these troughs, and upon lifting of this unstable airmass, at least scattered organized thunderstorm development should ensue, with multiple rounds of strong to severe storms possible. ...Day 4 (Thursday) - Northern Plains... The first in a series of mid-level troughs will eject into the northern Plains on Day 4/Thursday, encouraging surface lee troughing across the central and northern Plains. Dewpoints into the 70s F, beneath 8+ C/km mid-level lapse rates, will support strong to locally extreme instability by afternoon peak heating. The ejection of the upper trough will provide enough upper support for scattered thunderstorm development. Increasing westerly flow with height will result in straight, elongated hodographs. Supercells should be the main mode of convection, at least initially, with severe wind and hail the primary threats. ...Days 5-6 (Friday-Saturday) - Midwest toward the Great Lakes... The main mid-level trough will continue to slowly approach the Upper MS Valley as a preceding mid-level impulse continues to advance eastward. Potential exists for renewed thunderstorm development for portions of the Upper MS Valley and Midwest on Friday, spreading east with upper trough advancement toward the Great Lakes on Saturday. Rich low-level moisture beneath steep mid-level lapse rates will promote strong instability in the warm sector, amid modest vertical wind shear. Somewhere in this region, strong to severe storms are likely, with severe wind/hail the main concerns on both Friday and Saturday. The timing and location of thunderstorm initiation will be highly dependent on the position of remnant outflow boundaries from storms during previous days. Such details are quite challenging to point out this far in advance, precluding severe probabilities at this time, though probabilities will likely be needed in future outlooks. ...Days 7-8 (Sunday-Monday) - Upper Mississippi Valley... The next in a series of mid-level troughs will traverse the north-central CONUS toward the end of the period. Medium-range guidance consensus depicts extreme instability (i.e. well over 4000 J/kg MLCAPE) preceding this trough, along with strong enough westerly mid-level flow and accompanying vertical wind shear. As such, another episode of organized severe storms is possible in the Sunday/Monday time-frame. However, given the seasonal weak forcing associated with this second low-amplitude trough, run-to-run guidance consistency is desired before severe probabilities are delineated. Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 AM CDT Mon Jul 07 2025 Valid 091200Z - 101200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN PLAINS AND THE CAROLINAS INTO THE MID ATLANTIC... ...SUMMARY... At least isolated severe storms are possible in the northern Plains on Wednesday, with large hail the main threat, and an instance of very large hail cannot be ruled out. Isolated damaging gusts are also possible across parts of the eastern U.S. ...Synopsis... An upper ridge will persist over the Southwest as a low-amplitude mid-level trough approaches the Northeast on Wednesday. A pronounced mid-level impulse will crest the upper ridge and traverse the northern Rockies, supporting the rapid onset of surface lee troughing across the northern Plains. Here, rich low-level moisture will advect northward beneath colder temperatures aloft to support strong buoyancy amid modest vertical wind shear. At least isolated severe storms are likely. Isolated strong thunderstorms may also develop along portions of the East Coast. ...Northern Plains... A conditional severe threat is expected to develop ahead of the surface trough on Wednesday afternoon. Dewpoints into the 60s F will be overspread by 8+ C/km mid-level lapse rates by afternoon peak heating, yielding 3500-4500 J/kg MLCAPE. Modest northwesterly 500 mb flow rotating around the ridge will overspread the aforementioned southerly flow, resulting in modestly elongated hodographs and 30 kts of effective bulk shear. A dryline feature will advance eastward during the afternoon, serving as a primary lifting mechanism in tandem with strong surface heating given weak upper support. Isolated supercell development is possible, accompanied by a severe wind/hail risk. Given the degree of buoyancy in place, a conditional risk of 2+ inch hail exists should a supercell develop and become sustained. Weak upper support and lack of confidence for greater storm coverage is the primary limiting factor for higher severe probabilities at this time. ...Portions of the Carolinas into the Mid Atlantic... Scattered thunderstorms should develop atop a moist, weakly capped boundary layer by early afternoon. Though vertical wind shear should be weak and lapse rates will be poor, surface heating of the moist boundary layer will support 2000-3000 J/kg of tall/thin CAPE. As such, the stronger storms may produce wet downbursts and subsequent isolated damaging gusts. ..Squitieri.. 07/07/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 AM CDT Mon Jul 07 2025 Valid 091200Z - 101200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN PLAINS AND THE CAROLINAS INTO THE MID ATLANTIC... ...SUMMARY... At least isolated severe storms are possible in the northern Plains on Wednesday, with large hail the main threat, and an instance of very large hail cannot be ruled out. Isolated damaging gusts are also possible across parts of the eastern U.S. ...Synopsis... An upper ridge will persist over the Southwest as a low-amplitude mid-level trough approaches the Northeast on Wednesday. A pronounced mid-level impulse will crest the upper ridge and traverse the northern Rockies, supporting the rapid onset of surface lee troughing across the northern Plains. Here, rich low-level moisture will advect northward beneath colder temperatures aloft to support strong buoyancy amid modest vertical wind shear. At least isolated severe storms are likely. Isolated strong thunderstorms may also develop along portions of the East Coast. ...Northern Plains... A conditional severe threat is expected to develop ahead of the surface trough on Wednesday afternoon. Dewpoints into the 60s F will be overspread by 8+ C/km mid-level lapse rates by afternoon peak heating, yielding 3500-4500 J/kg MLCAPE. Modest northwesterly 500 mb flow rotating around the ridge will overspread the aforementioned southerly flow, resulting in modestly elongated hodographs and 30 kts of effective bulk shear. A dryline feature will advance eastward during the afternoon, serving as a primary lifting mechanism in tandem with strong surface heating given weak upper support. Isolated supercell development is possible, accompanied by a severe wind/hail risk. Given the degree of buoyancy in place, a conditional risk of 2+ inch hail exists should a supercell develop and become sustained. Weak upper support and lack of confidence for greater storm coverage is the primary limiting factor for higher severe probabilities at this time. ...Portions of the Carolinas into the Mid Atlantic... Scattered thunderstorms should develop atop a moist, weakly capped boundary layer by early afternoon. Though vertical wind shear should be weak and lapse rates will be poor, surface heating of the moist boundary layer will support 2000-3000 J/kg of tall/thin CAPE. As such, the stronger storms may produce wet downbursts and subsequent isolated damaging gusts. ..Squitieri.. 07/07/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 AM CDT Mon Jul 07 2025 Valid 091200Z - 101200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN PLAINS AND THE CAROLINAS INTO THE MID ATLANTIC... ...SUMMARY... At least isolated severe storms are possible in the northern Plains on Wednesday, with large hail the main threat, and an instance of very large hail cannot be ruled out. Isolated damaging gusts are also possible across parts of the eastern U.S. ...Synopsis... An upper ridge will persist over the Southwest as a low-amplitude mid-level trough approaches the Northeast on Wednesday. A pronounced mid-level impulse will crest the upper ridge and traverse the northern Rockies, supporting the rapid onset of surface lee troughing across the northern Plains. Here, rich low-level moisture will advect northward beneath colder temperatures aloft to support strong buoyancy amid modest vertical wind shear. At least isolated severe storms are likely. Isolated strong thunderstorms may also develop along portions of the East Coast. ...Northern Plains... A conditional severe threat is expected to develop ahead of the surface trough on Wednesday afternoon. Dewpoints into the 60s F will be overspread by 8+ C/km mid-level lapse rates by afternoon peak heating, yielding 3500-4500 J/kg MLCAPE. Modest northwesterly 500 mb flow rotating around the ridge will overspread the aforementioned southerly flow, resulting in modestly elongated hodographs and 30 kts of effective bulk shear. A dryline feature will advance eastward during the afternoon, serving as a primary lifting mechanism in tandem with strong surface heating given weak upper support. Isolated supercell development is possible, accompanied by a severe wind/hail risk. Given the degree of buoyancy in place, a conditional risk of 2+ inch hail exists should a supercell develop and become sustained. Weak upper support and lack of confidence for greater storm coverage is the primary limiting factor for higher severe probabilities at this time. ...Portions of the Carolinas into the Mid Atlantic... Scattered thunderstorms should develop atop a moist, weakly capped boundary layer by early afternoon. Though vertical wind shear should be weak and lapse rates will be poor, surface heating of the moist boundary layer will support 2000-3000 J/kg of tall/thin CAPE. As such, the stronger storms may produce wet downbursts and subsequent isolated damaging gusts. ..Squitieri.. 07/07/2025 Read more

SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0226 AM CDT Mon Jul 07 2025 Valid 091200Z - 101200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE NORTHERN PLAINS AND THE CAROLINAS INTO THE MID ATLANTIC... ...SUMMARY... At least isolated severe storms are possible in the northern Plains on Wednesday, with large hail the main threat, and an instance of very large hail cannot be ruled out. Isolated damaging gusts are also possible across parts of the eastern U.S. ...Synopsis... An upper ridge will persist over the Southwest as a low-amplitude mid-level trough approaches the Northeast on Wednesday. A pronounced mid-level impulse will crest the upper ridge and traverse the northern Rockies, supporting the rapid onset of surface lee troughing across the northern Plains. Here, rich low-level moisture will advect northward beneath colder temperatures aloft to support strong buoyancy amid modest vertical wind shear. At least isolated severe storms are likely. Isolated strong thunderstorms may also develop along portions of the East Coast. ...Northern Plains... A conditional severe threat is expected to develop ahead of the surface trough on Wednesday afternoon. Dewpoints into the 60s F will be overspread by 8+ C/km mid-level lapse rates by afternoon peak heating, yielding 3500-4500 J/kg MLCAPE. Modest northwesterly 500 mb flow rotating around the ridge will overspread the aforementioned southerly flow, resulting in modestly elongated hodographs and 30 kts of effective bulk shear. A dryline feature will advance eastward during the afternoon, serving as a primary lifting mechanism in tandem with strong surface heating given weak upper support. Isolated supercell development is possible, accompanied by a severe wind/hail risk. Given the degree of buoyancy in place, a conditional risk of 2+ inch hail exists should a supercell develop and become sustained. Weak upper support and lack of confidence for greater storm coverage is the primary limiting factor for higher severe probabilities at this time. ...Portions of the Carolinas into the Mid Atlantic... Scattered thunderstorms should develop atop a moist, weakly capped boundary layer by early afternoon. Though vertical wind shear should be weak and lapse rates will be poor, surface heating of the moist boundary layer will support 2000-3000 J/kg of tall/thin CAPE. As such, the stronger storms may produce wet downbursts and subsequent isolated damaging gusts. ..Squitieri.. 07/07/2025 Read more