Severe Storms

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0440 PM CDT Thu Jul 24 2025 Valid 261200Z - 011200Z ...Synopsis... By this weekend, a mid to upper-level shortwave trough will traverse central CA and the Great Basin. Increasing southwesterly mid-level flow from the Southwest into the Rockies will accompany this feature, as the height gradient tightens. Farther east, the subtropical ridge will begin to expand westward over the southern and central CONUS into early next week. Pacific mid to upper-level troughing will continue through this time period as well, leading to persistent, deep southerly flow developing on the western fringe of the ridge from CA to the Pacific Northwest. ...D3/Saturday... Continued mid-level ascent associated with the CA trough will aid in elevated moist convection developing again from northern NV, far southeast OR, and southern ID. Projected PWATs D3/Saturday within this region, combined with receptive fuels and relatively low QPF, should provide another environment favorable for isolated dry thunderstorms. Farther south from northwest AZ, into southeast UT, and far western CO, a deeply mixed boundary layer will allow for momentum transfer of the stronger flow aloft. Confidence in these breezy southwest winds developing D3/Saturday has increased enough to introduce a low probability area for the aforementioned region. Low RH and increasingly receptive fuels will also be present there. ..Barnes.. 07/24/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0440 PM CDT Thu Jul 24 2025 Valid 261200Z - 011200Z ...Synopsis... By this weekend, a mid to upper-level shortwave trough will traverse central CA and the Great Basin. Increasing southwesterly mid-level flow from the Southwest into the Rockies will accompany this feature, as the height gradient tightens. Farther east, the subtropical ridge will begin to expand westward over the southern and central CONUS into early next week. Pacific mid to upper-level troughing will continue through this time period as well, leading to persistent, deep southerly flow developing on the western fringe of the ridge from CA to the Pacific Northwest. ...D3/Saturday... Continued mid-level ascent associated with the CA trough will aid in elevated moist convection developing again from northern NV, far southeast OR, and southern ID. Projected PWATs D3/Saturday within this region, combined with receptive fuels and relatively low QPF, should provide another environment favorable for isolated dry thunderstorms. Farther south from northwest AZ, into southeast UT, and far western CO, a deeply mixed boundary layer will allow for momentum transfer of the stronger flow aloft. Confidence in these breezy southwest winds developing D3/Saturday has increased enough to introduce a low probability area for the aforementioned region. Low RH and increasingly receptive fuels will also be present there. ..Barnes.. 07/24/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0440 PM CDT Thu Jul 24 2025 Valid 261200Z - 011200Z ...Synopsis... By this weekend, a mid to upper-level shortwave trough will traverse central CA and the Great Basin. Increasing southwesterly mid-level flow from the Southwest into the Rockies will accompany this feature, as the height gradient tightens. Farther east, the subtropical ridge will begin to expand westward over the southern and central CONUS into early next week. Pacific mid to upper-level troughing will continue through this time period as well, leading to persistent, deep southerly flow developing on the western fringe of the ridge from CA to the Pacific Northwest. ...D3/Saturday... Continued mid-level ascent associated with the CA trough will aid in elevated moist convection developing again from northern NV, far southeast OR, and southern ID. Projected PWATs D3/Saturday within this region, combined with receptive fuels and relatively low QPF, should provide another environment favorable for isolated dry thunderstorms. Farther south from northwest AZ, into southeast UT, and far western CO, a deeply mixed boundary layer will allow for momentum transfer of the stronger flow aloft. Confidence in these breezy southwest winds developing D3/Saturday has increased enough to introduce a low probability area for the aforementioned region. Low RH and increasingly receptive fuels will also be present there. ..Barnes.. 07/24/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0440 PM CDT Thu Jul 24 2025 Valid 261200Z - 011200Z ...Synopsis... By this weekend, a mid to upper-level shortwave trough will traverse central CA and the Great Basin. Increasing southwesterly mid-level flow from the Southwest into the Rockies will accompany this feature, as the height gradient tightens. Farther east, the subtropical ridge will begin to expand westward over the southern and central CONUS into early next week. Pacific mid to upper-level troughing will continue through this time period as well, leading to persistent, deep southerly flow developing on the western fringe of the ridge from CA to the Pacific Northwest. ...D3/Saturday... Continued mid-level ascent associated with the CA trough will aid in elevated moist convection developing again from northern NV, far southeast OR, and southern ID. Projected PWATs D3/Saturday within this region, combined with receptive fuels and relatively low QPF, should provide another environment favorable for isolated dry thunderstorms. Farther south from northwest AZ, into southeast UT, and far western CO, a deeply mixed boundary layer will allow for momentum transfer of the stronger flow aloft. Confidence in these breezy southwest winds developing D3/Saturday has increased enough to introduce a low probability area for the aforementioned region. Low RH and increasingly receptive fuels will also be present there. ..Barnes.. 07/24/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0440 PM CDT Thu Jul 24 2025 Valid 261200Z - 011200Z ...Synopsis... By this weekend, a mid to upper-level shortwave trough will traverse central CA and the Great Basin. Increasing southwesterly mid-level flow from the Southwest into the Rockies will accompany this feature, as the height gradient tightens. Farther east, the subtropical ridge will begin to expand westward over the southern and central CONUS into early next week. Pacific mid to upper-level troughing will continue through this time period as well, leading to persistent, deep southerly flow developing on the western fringe of the ridge from CA to the Pacific Northwest. ...D3/Saturday... Continued mid-level ascent associated with the CA trough will aid in elevated moist convection developing again from northern NV, far southeast OR, and southern ID. Projected PWATs D3/Saturday within this region, combined with receptive fuels and relatively low QPF, should provide another environment favorable for isolated dry thunderstorms. Farther south from northwest AZ, into southeast UT, and far western CO, a deeply mixed boundary layer will allow for momentum transfer of the stronger flow aloft. Confidence in these breezy southwest winds developing D3/Saturday has increased enough to introduce a low probability area for the aforementioned region. Low RH and increasingly receptive fuels will also be present there. ..Barnes.. 07/24/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0440 PM CDT Thu Jul 24 2025 Valid 261200Z - 011200Z ...Synopsis... By this weekend, a mid to upper-level shortwave trough will traverse central CA and the Great Basin. Increasing southwesterly mid-level flow from the Southwest into the Rockies will accompany this feature, as the height gradient tightens. Farther east, the subtropical ridge will begin to expand westward over the southern and central CONUS into early next week. Pacific mid to upper-level troughing will continue through this time period as well, leading to persistent, deep southerly flow developing on the western fringe of the ridge from CA to the Pacific Northwest. ...D3/Saturday... Continued mid-level ascent associated with the CA trough will aid in elevated moist convection developing again from northern NV, far southeast OR, and southern ID. Projected PWATs D3/Saturday within this region, combined with receptive fuels and relatively low QPF, should provide another environment favorable for isolated dry thunderstorms. Farther south from northwest AZ, into southeast UT, and far western CO, a deeply mixed boundary layer will allow for momentum transfer of the stronger flow aloft. Confidence in these breezy southwest winds developing D3/Saturday has increased enough to introduce a low probability area for the aforementioned region. Low RH and increasingly receptive fuels will also be present there. ..Barnes.. 07/24/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0440 PM CDT Thu Jul 24 2025 Valid 261200Z - 011200Z ...Synopsis... By this weekend, a mid to upper-level shortwave trough will traverse central CA and the Great Basin. Increasing southwesterly mid-level flow from the Southwest into the Rockies will accompany this feature, as the height gradient tightens. Farther east, the subtropical ridge will begin to expand westward over the southern and central CONUS into early next week. Pacific mid to upper-level troughing will continue through this time period as well, leading to persistent, deep southerly flow developing on the western fringe of the ridge from CA to the Pacific Northwest. ...D3/Saturday... Continued mid-level ascent associated with the CA trough will aid in elevated moist convection developing again from northern NV, far southeast OR, and southern ID. Projected PWATs D3/Saturday within this region, combined with receptive fuels and relatively low QPF, should provide another environment favorable for isolated dry thunderstorms. Farther south from northwest AZ, into southeast UT, and far western CO, a deeply mixed boundary layer will allow for momentum transfer of the stronger flow aloft. Confidence in these breezy southwest winds developing D3/Saturday has increased enough to introduce a low probability area for the aforementioned region. Low RH and increasingly receptive fuels will also be present there. ..Barnes.. 07/24/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1772 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF EASTERN WYOMING AND NORTHERN COLORADO
Mesoscale Discussion 1772 NWS Storm Prediction Center Norman OK 0241 PM CDT Thu Jul 24 2025 Areas affected...parts of eastern Wyoming and northern Colorado Concerning...Severe potential...Watch unlikely Valid 241941Z - 242145Z Probability of Watch Issuance...20 percent SUMMARY...Storms may produce a few instance of large hail and a few severe gusts across portions of eastern Wyoming and northern Colorado. A watch is not anticipated. DISCUSSION...Convection has developed along the mountains across parts of eastern Wyoming and northern Colorado, where diurnal inhibition has eroded. Farther east across the High Plains, some inhibition remains for mixed-layer parcels, but additional heating should continue to erode the MLCINH as the afternoon progresses. Kinematically, the region is on the southern periphery of a modest mid-level jet. This should provide sufficient shear for at least transient supercells, and in some places low-level wind profiles favor left-moving supercells. Given the long hodographs and steep lapse rates with low freezing levels, some hail is possible with the strongest storms. Shear decreases with southward extent, so this may put a limit on the southern extent of the hail risk. With time, storms may begin to cluster, and these clusters may also produce a risk for severe gusts given the relatively dry boundary layer and steep low-level lapse rates. Given the expected sparse coverage of severe weather, a watch is not anticipated. ..Supinie/Guyer.. 07/24/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...UNR...PUB...BOU...CYS...BYZ...RIW... LAT...LON 39540601 40210611 41300617 43490650 44510673 44900650 45020582 44810504 43510459 42510437 41880423 40910409 39590395 39050428 38760466 38770542 39120588 39540601 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

MD 1771 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PORTIONS OF NORTHERN IL/IN INTO SOUTHERN LOWER MI
Mesoscale Discussion 1771 NWS Storm Prediction Center Norman OK 0210 PM CDT Thu Jul 24 2025 Areas affected...portions of northern IL/IN into southern Lower MI Concerning...Severe potential...Watch possible Valid 241910Z - 242115Z Probability of Watch Issuance...60 percent SUMMARY...Isolated strong to severe wind gusts are possible this afternoon into early evening across portions of northeast Illinois, northern Indiana, and southern Lower Michigan. DISCUSSION...Isolated thunderstorms are developing across northeast IL as of 19z ahead of surface boundary moving slowly southeastward. Ahead of the boundary and initial thunderstorm development, strong heating into the low 90s, with dewpoints in the mid/upper 70s, is resulting in a corridor of moderate/strong instability (MLCAPE up to 3000 J/kg). Deep shear will remain weak across the region, but effective shear magnitudes around 20-30 kt may be sufficient for a few organized cells/clusters. Modified RAP forecast soundings show large instability, with steep low-level lapse rates from 7-8 C/km in the 0-3 km layer. Given the very moist and strongly unstable airmass, isolated downbursts producing strong to severe gusts are possible through the afternoon into early evening. Some uncertainty remains regarding storm coverage, especially given veering low-level flow, reducing convergence/lift along the surface boundary. Nevertheless, any storm that does develop could produce locally damaging gusts. A severe thunderstorm watch may be needed at some point this afternoon. ..Leitman/Guyer.. 07/24/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...DTX...IWX...GRR...IND...LOT...ILX...DVN... LAT...LON 41818422 41428473 40638685 40478776 40568856 40878952 41308972 41558955 42008844 43338482 43328451 43158423 42928408 42298413 41818422 MOST PROBABLE PEAK WIND GUST...55-70 MPH Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Thu Jul 24 2025 Valid 242000Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDWEST/GREAT LAKES... ...SUMMARY... Locally damaging thunderstorm wind gusts are possible from parts of the Great Lakes to the central and southern Plains this afternoon and evening. Isolated severe storms will also pose a risk of hail and severe wind gusts over portions of the northern and central High Plains. ...20z Update... The previous forecast largely remains on track. Thunderstorm development is underway across portions of northern IL, which should intensify and track into northern IN and southern MI through the evening hours. Severe hail/wind risk probabilities were reduced across far northern lower MI due to the recent passage of deep convection and an influx of cooler/lower theta-e air. See the previous discussion below as well as MCDs #1771 and #1772 for additional details. ..Moore.. 07/24/2025 .PREV DISCUSSION... /ISSUED 1134 AM CDT Thu Jul 24 2025/ ...Northern Lower Michigan... Ahead of an MCV, a well-organized cluster of storms will pose at a short-term severe risk across far northern Lower Michigan early this afternoon, although there is some potential for additional development southwestward along the front this afternoon. ...Midwest/Lake Michigan vicinity to south-central Plains... Aside from an MCV nearing northern Lake Michigan, at least one additional eastward-moving MCV exists across eastern Iowa, nearing the southwest Wisconsin/northwest Illinois border vicinity as of midday. Some multi-layer cloud debris still persists, and a pre-frontal veering of winds (westerly component) has occurred in some areas. However, heating of a very moist air mass (70s F surface dewpoints) will lead to strong destabilization (2500-4000 J/kg MLCAPE) and relatively weak boundary-layer inhibition this afternoon near/ahead of the front. Most 12z global guidance/HREF members are more aggressive in the coverage/intensity of convection than morning HRRR/RRFS/MPAS runs, particularly for northern portions of Illinois/Indiana into Lower Michigan. Where deep convection does develop/sustain this afternoon, MCV-aided enhancement of low/mid-tropospheric flow will support some well-organized bands/clusters of storms with wind damage as the most common severe risk across northern Missouri, northern portions of Illinois/Indiana, into Lower Michigan. A more localized/pulse-type severe risk is anticipated farther southwest into southern Kansas/northwest Oklahoma. ...High Plains... Moderate instability will develop across parts of the northern/central High Plains this afternoon. Large-scale ascent will tend to be weak behind a departing mid-level shortwave trough. Even so, convective development should occur near the adjacent higher terrain this afternoon. Effective shear of 25-40 kt will support some updraft organization. Initially discrete cells may pose an isolated threat for hail. Some outflow amalgamation/mergers could eventually occur, with a threat of strong to locally severe gusts spreading eastward into the evening before convection eventually weakens. Farther south across portions of the southern High Plains, scattered to numerous thunderstorms are also expected to develop this afternoon/early evening. Deep-layer shear will remain weak across this region, but localized strong to severe outflow gusts may still be possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Thu Jul 24 2025 Valid 242000Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDWEST/GREAT LAKES... ...SUMMARY... Locally damaging thunderstorm wind gusts are possible from parts of the Great Lakes to the central and southern Plains this afternoon and evening. Isolated severe storms will also pose a risk of hail and severe wind gusts over portions of the northern and central High Plains. ...20z Update... The previous forecast largely remains on track. Thunderstorm development is underway across portions of northern IL, which should intensify and track into northern IN and southern MI through the evening hours. Severe hail/wind risk probabilities were reduced across far northern lower MI due to the recent passage of deep convection and an influx of cooler/lower theta-e air. See the previous discussion below as well as MCDs #1771 and #1772 for additional details. ..Moore.. 07/24/2025 .PREV DISCUSSION... /ISSUED 1134 AM CDT Thu Jul 24 2025/ ...Northern Lower Michigan... Ahead of an MCV, a well-organized cluster of storms will pose at a short-term severe risk across far northern Lower Michigan early this afternoon, although there is some potential for additional development southwestward along the front this afternoon. ...Midwest/Lake Michigan vicinity to south-central Plains... Aside from an MCV nearing northern Lake Michigan, at least one additional eastward-moving MCV exists across eastern Iowa, nearing the southwest Wisconsin/northwest Illinois border vicinity as of midday. Some multi-layer cloud debris still persists, and a pre-frontal veering of winds (westerly component) has occurred in some areas. However, heating of a very moist air mass (70s F surface dewpoints) will lead to strong destabilization (2500-4000 J/kg MLCAPE) and relatively weak boundary-layer inhibition this afternoon near/ahead of the front. Most 12z global guidance/HREF members are more aggressive in the coverage/intensity of convection than morning HRRR/RRFS/MPAS runs, particularly for northern portions of Illinois/Indiana into Lower Michigan. Where deep convection does develop/sustain this afternoon, MCV-aided enhancement of low/mid-tropospheric flow will support some well-organized bands/clusters of storms with wind damage as the most common severe risk across northern Missouri, northern portions of Illinois/Indiana, into Lower Michigan. A more localized/pulse-type severe risk is anticipated farther southwest into southern Kansas/northwest Oklahoma. ...High Plains... Moderate instability will develop across parts of the northern/central High Plains this afternoon. Large-scale ascent will tend to be weak behind a departing mid-level shortwave trough. Even so, convective development should occur near the adjacent higher terrain this afternoon. Effective shear of 25-40 kt will support some updraft organization. Initially discrete cells may pose an isolated threat for hail. Some outflow amalgamation/mergers could eventually occur, with a threat of strong to locally severe gusts spreading eastward into the evening before convection eventually weakens. Farther south across portions of the southern High Plains, scattered to numerous thunderstorms are also expected to develop this afternoon/early evening. Deep-layer shear will remain weak across this region, but localized strong to severe outflow gusts may still be possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Thu Jul 24 2025 Valid 242000Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDWEST/GREAT LAKES... ...SUMMARY... Locally damaging thunderstorm wind gusts are possible from parts of the Great Lakes to the central and southern Plains this afternoon and evening. Isolated severe storms will also pose a risk of hail and severe wind gusts over portions of the northern and central High Plains. ...20z Update... The previous forecast largely remains on track. Thunderstorm development is underway across portions of northern IL, which should intensify and track into northern IN and southern MI through the evening hours. Severe hail/wind risk probabilities were reduced across far northern lower MI due to the recent passage of deep convection and an influx of cooler/lower theta-e air. See the previous discussion below as well as MCDs #1771 and #1772 for additional details. ..Moore.. 07/24/2025 .PREV DISCUSSION... /ISSUED 1134 AM CDT Thu Jul 24 2025/ ...Northern Lower Michigan... Ahead of an MCV, a well-organized cluster of storms will pose at a short-term severe risk across far northern Lower Michigan early this afternoon, although there is some potential for additional development southwestward along the front this afternoon. ...Midwest/Lake Michigan vicinity to south-central Plains... Aside from an MCV nearing northern Lake Michigan, at least one additional eastward-moving MCV exists across eastern Iowa, nearing the southwest Wisconsin/northwest Illinois border vicinity as of midday. Some multi-layer cloud debris still persists, and a pre-frontal veering of winds (westerly component) has occurred in some areas. However, heating of a very moist air mass (70s F surface dewpoints) will lead to strong destabilization (2500-4000 J/kg MLCAPE) and relatively weak boundary-layer inhibition this afternoon near/ahead of the front. Most 12z global guidance/HREF members are more aggressive in the coverage/intensity of convection than morning HRRR/RRFS/MPAS runs, particularly for northern portions of Illinois/Indiana into Lower Michigan. Where deep convection does develop/sustain this afternoon, MCV-aided enhancement of low/mid-tropospheric flow will support some well-organized bands/clusters of storms with wind damage as the most common severe risk across northern Missouri, northern portions of Illinois/Indiana, into Lower Michigan. A more localized/pulse-type severe risk is anticipated farther southwest into southern Kansas/northwest Oklahoma. ...High Plains... Moderate instability will develop across parts of the northern/central High Plains this afternoon. Large-scale ascent will tend to be weak behind a departing mid-level shortwave trough. Even so, convective development should occur near the adjacent higher terrain this afternoon. Effective shear of 25-40 kt will support some updraft organization. Initially discrete cells may pose an isolated threat for hail. Some outflow amalgamation/mergers could eventually occur, with a threat of strong to locally severe gusts spreading eastward into the evening before convection eventually weakens. Farther south across portions of the southern High Plains, scattered to numerous thunderstorms are also expected to develop this afternoon/early evening. Deep-layer shear will remain weak across this region, but localized strong to severe outflow gusts may still be possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Thu Jul 24 2025 Valid 242000Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDWEST/GREAT LAKES... ...SUMMARY... Locally damaging thunderstorm wind gusts are possible from parts of the Great Lakes to the central and southern Plains this afternoon and evening. Isolated severe storms will also pose a risk of hail and severe wind gusts over portions of the northern and central High Plains. ...20z Update... The previous forecast largely remains on track. Thunderstorm development is underway across portions of northern IL, which should intensify and track into northern IN and southern MI through the evening hours. Severe hail/wind risk probabilities were reduced across far northern lower MI due to the recent passage of deep convection and an influx of cooler/lower theta-e air. See the previous discussion below as well as MCDs #1771 and #1772 for additional details. ..Moore.. 07/24/2025 .PREV DISCUSSION... /ISSUED 1134 AM CDT Thu Jul 24 2025/ ...Northern Lower Michigan... Ahead of an MCV, a well-organized cluster of storms will pose at a short-term severe risk across far northern Lower Michigan early this afternoon, although there is some potential for additional development southwestward along the front this afternoon. ...Midwest/Lake Michigan vicinity to south-central Plains... Aside from an MCV nearing northern Lake Michigan, at least one additional eastward-moving MCV exists across eastern Iowa, nearing the southwest Wisconsin/northwest Illinois border vicinity as of midday. Some multi-layer cloud debris still persists, and a pre-frontal veering of winds (westerly component) has occurred in some areas. However, heating of a very moist air mass (70s F surface dewpoints) will lead to strong destabilization (2500-4000 J/kg MLCAPE) and relatively weak boundary-layer inhibition this afternoon near/ahead of the front. Most 12z global guidance/HREF members are more aggressive in the coverage/intensity of convection than morning HRRR/RRFS/MPAS runs, particularly for northern portions of Illinois/Indiana into Lower Michigan. Where deep convection does develop/sustain this afternoon, MCV-aided enhancement of low/mid-tropospheric flow will support some well-organized bands/clusters of storms with wind damage as the most common severe risk across northern Missouri, northern portions of Illinois/Indiana, into Lower Michigan. A more localized/pulse-type severe risk is anticipated farther southwest into southern Kansas/northwest Oklahoma. ...High Plains... Moderate instability will develop across parts of the northern/central High Plains this afternoon. Large-scale ascent will tend to be weak behind a departing mid-level shortwave trough. Even so, convective development should occur near the adjacent higher terrain this afternoon. Effective shear of 25-40 kt will support some updraft organization. Initially discrete cells may pose an isolated threat for hail. Some outflow amalgamation/mergers could eventually occur, with a threat of strong to locally severe gusts spreading eastward into the evening before convection eventually weakens. Farther south across portions of the southern High Plains, scattered to numerous thunderstorms are also expected to develop this afternoon/early evening. Deep-layer shear will remain weak across this region, but localized strong to severe outflow gusts may still be possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Thu Jul 24 2025 Valid 242000Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDWEST/GREAT LAKES... ...SUMMARY... Locally damaging thunderstorm wind gusts are possible from parts of the Great Lakes to the central and southern Plains this afternoon and evening. Isolated severe storms will also pose a risk of hail and severe wind gusts over portions of the northern and central High Plains. ...20z Update... The previous forecast largely remains on track. Thunderstorm development is underway across portions of northern IL, which should intensify and track into northern IN and southern MI through the evening hours. Severe hail/wind risk probabilities were reduced across far northern lower MI due to the recent passage of deep convection and an influx of cooler/lower theta-e air. See the previous discussion below as well as MCDs #1771 and #1772 for additional details. ..Moore.. 07/24/2025 .PREV DISCUSSION... /ISSUED 1134 AM CDT Thu Jul 24 2025/ ...Northern Lower Michigan... Ahead of an MCV, a well-organized cluster of storms will pose at a short-term severe risk across far northern Lower Michigan early this afternoon, although there is some potential for additional development southwestward along the front this afternoon. ...Midwest/Lake Michigan vicinity to south-central Plains... Aside from an MCV nearing northern Lake Michigan, at least one additional eastward-moving MCV exists across eastern Iowa, nearing the southwest Wisconsin/northwest Illinois border vicinity as of midday. Some multi-layer cloud debris still persists, and a pre-frontal veering of winds (westerly component) has occurred in some areas. However, heating of a very moist air mass (70s F surface dewpoints) will lead to strong destabilization (2500-4000 J/kg MLCAPE) and relatively weak boundary-layer inhibition this afternoon near/ahead of the front. Most 12z global guidance/HREF members are more aggressive in the coverage/intensity of convection than morning HRRR/RRFS/MPAS runs, particularly for northern portions of Illinois/Indiana into Lower Michigan. Where deep convection does develop/sustain this afternoon, MCV-aided enhancement of low/mid-tropospheric flow will support some well-organized bands/clusters of storms with wind damage as the most common severe risk across northern Missouri, northern portions of Illinois/Indiana, into Lower Michigan. A more localized/pulse-type severe risk is anticipated farther southwest into southern Kansas/northwest Oklahoma. ...High Plains... Moderate instability will develop across parts of the northern/central High Plains this afternoon. Large-scale ascent will tend to be weak behind a departing mid-level shortwave trough. Even so, convective development should occur near the adjacent higher terrain this afternoon. Effective shear of 25-40 kt will support some updraft organization. Initially discrete cells may pose an isolated threat for hail. Some outflow amalgamation/mergers could eventually occur, with a threat of strong to locally severe gusts spreading eastward into the evening before convection eventually weakens. Farther south across portions of the southern High Plains, scattered to numerous thunderstorms are also expected to develop this afternoon/early evening. Deep-layer shear will remain weak across this region, but localized strong to severe outflow gusts may still be possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Thu Jul 24 2025 Valid 242000Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDWEST/GREAT LAKES... ...SUMMARY... Locally damaging thunderstorm wind gusts are possible from parts of the Great Lakes to the central and southern Plains this afternoon and evening. Isolated severe storms will also pose a risk of hail and severe wind gusts over portions of the northern and central High Plains. ...20z Update... The previous forecast largely remains on track. Thunderstorm development is underway across portions of northern IL, which should intensify and track into northern IN and southern MI through the evening hours. Severe hail/wind risk probabilities were reduced across far northern lower MI due to the recent passage of deep convection and an influx of cooler/lower theta-e air. See the previous discussion below as well as MCDs #1771 and #1772 for additional details. ..Moore.. 07/24/2025 .PREV DISCUSSION... /ISSUED 1134 AM CDT Thu Jul 24 2025/ ...Northern Lower Michigan... Ahead of an MCV, a well-organized cluster of storms will pose at a short-term severe risk across far northern Lower Michigan early this afternoon, although there is some potential for additional development southwestward along the front this afternoon. ...Midwest/Lake Michigan vicinity to south-central Plains... Aside from an MCV nearing northern Lake Michigan, at least one additional eastward-moving MCV exists across eastern Iowa, nearing the southwest Wisconsin/northwest Illinois border vicinity as of midday. Some multi-layer cloud debris still persists, and a pre-frontal veering of winds (westerly component) has occurred in some areas. However, heating of a very moist air mass (70s F surface dewpoints) will lead to strong destabilization (2500-4000 J/kg MLCAPE) and relatively weak boundary-layer inhibition this afternoon near/ahead of the front. Most 12z global guidance/HREF members are more aggressive in the coverage/intensity of convection than morning HRRR/RRFS/MPAS runs, particularly for northern portions of Illinois/Indiana into Lower Michigan. Where deep convection does develop/sustain this afternoon, MCV-aided enhancement of low/mid-tropospheric flow will support some well-organized bands/clusters of storms with wind damage as the most common severe risk across northern Missouri, northern portions of Illinois/Indiana, into Lower Michigan. A more localized/pulse-type severe risk is anticipated farther southwest into southern Kansas/northwest Oklahoma. ...High Plains... Moderate instability will develop across parts of the northern/central High Plains this afternoon. Large-scale ascent will tend to be weak behind a departing mid-level shortwave trough. Even so, convective development should occur near the adjacent higher terrain this afternoon. Effective shear of 25-40 kt will support some updraft organization. Initially discrete cells may pose an isolated threat for hail. Some outflow amalgamation/mergers could eventually occur, with a threat of strong to locally severe gusts spreading eastward into the evening before convection eventually weakens. Farther south across portions of the southern High Plains, scattered to numerous thunderstorms are also expected to develop this afternoon/early evening. Deep-layer shear will remain weak across this region, but localized strong to severe outflow gusts may still be possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Thu Jul 24 2025 Valid 242000Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDWEST/GREAT LAKES... ...SUMMARY... Locally damaging thunderstorm wind gusts are possible from parts of the Great Lakes to the central and southern Plains this afternoon and evening. Isolated severe storms will also pose a risk of hail and severe wind gusts over portions of the northern and central High Plains. ...20z Update... The previous forecast largely remains on track. Thunderstorm development is underway across portions of northern IL, which should intensify and track into northern IN and southern MI through the evening hours. Severe hail/wind risk probabilities were reduced across far northern lower MI due to the recent passage of deep convection and an influx of cooler/lower theta-e air. See the previous discussion below as well as MCDs #1771 and #1772 for additional details. ..Moore.. 07/24/2025 .PREV DISCUSSION... /ISSUED 1134 AM CDT Thu Jul 24 2025/ ...Northern Lower Michigan... Ahead of an MCV, a well-organized cluster of storms will pose at a short-term severe risk across far northern Lower Michigan early this afternoon, although there is some potential for additional development southwestward along the front this afternoon. ...Midwest/Lake Michigan vicinity to south-central Plains... Aside from an MCV nearing northern Lake Michigan, at least one additional eastward-moving MCV exists across eastern Iowa, nearing the southwest Wisconsin/northwest Illinois border vicinity as of midday. Some multi-layer cloud debris still persists, and a pre-frontal veering of winds (westerly component) has occurred in some areas. However, heating of a very moist air mass (70s F surface dewpoints) will lead to strong destabilization (2500-4000 J/kg MLCAPE) and relatively weak boundary-layer inhibition this afternoon near/ahead of the front. Most 12z global guidance/HREF members are more aggressive in the coverage/intensity of convection than morning HRRR/RRFS/MPAS runs, particularly for northern portions of Illinois/Indiana into Lower Michigan. Where deep convection does develop/sustain this afternoon, MCV-aided enhancement of low/mid-tropospheric flow will support some well-organized bands/clusters of storms with wind damage as the most common severe risk across northern Missouri, northern portions of Illinois/Indiana, into Lower Michigan. A more localized/pulse-type severe risk is anticipated farther southwest into southern Kansas/northwest Oklahoma. ...High Plains... Moderate instability will develop across parts of the northern/central High Plains this afternoon. Large-scale ascent will tend to be weak behind a departing mid-level shortwave trough. Even so, convective development should occur near the adjacent higher terrain this afternoon. Effective shear of 25-40 kt will support some updraft organization. Initially discrete cells may pose an isolated threat for hail. Some outflow amalgamation/mergers could eventually occur, with a threat of strong to locally severe gusts spreading eastward into the evening before convection eventually weakens. Farther south across portions of the southern High Plains, scattered to numerous thunderstorms are also expected to develop this afternoon/early evening. Deep-layer shear will remain weak across this region, but localized strong to severe outflow gusts may still be possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Thu Jul 24 2025 Valid 242000Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDWEST/GREAT LAKES... ...SUMMARY... Locally damaging thunderstorm wind gusts are possible from parts of the Great Lakes to the central and southern Plains this afternoon and evening. Isolated severe storms will also pose a risk of hail and severe wind gusts over portions of the northern and central High Plains. ...20z Update... The previous forecast largely remains on track. Thunderstorm development is underway across portions of northern IL, which should intensify and track into northern IN and southern MI through the evening hours. Severe hail/wind risk probabilities were reduced across far northern lower MI due to the recent passage of deep convection and an influx of cooler/lower theta-e air. See the previous discussion below as well as MCDs #1771 and #1772 for additional details. ..Moore.. 07/24/2025 .PREV DISCUSSION... /ISSUED 1134 AM CDT Thu Jul 24 2025/ ...Northern Lower Michigan... Ahead of an MCV, a well-organized cluster of storms will pose at a short-term severe risk across far northern Lower Michigan early this afternoon, although there is some potential for additional development southwestward along the front this afternoon. ...Midwest/Lake Michigan vicinity to south-central Plains... Aside from an MCV nearing northern Lake Michigan, at least one additional eastward-moving MCV exists across eastern Iowa, nearing the southwest Wisconsin/northwest Illinois border vicinity as of midday. Some multi-layer cloud debris still persists, and a pre-frontal veering of winds (westerly component) has occurred in some areas. However, heating of a very moist air mass (70s F surface dewpoints) will lead to strong destabilization (2500-4000 J/kg MLCAPE) and relatively weak boundary-layer inhibition this afternoon near/ahead of the front. Most 12z global guidance/HREF members are more aggressive in the coverage/intensity of convection than morning HRRR/RRFS/MPAS runs, particularly for northern portions of Illinois/Indiana into Lower Michigan. Where deep convection does develop/sustain this afternoon, MCV-aided enhancement of low/mid-tropospheric flow will support some well-organized bands/clusters of storms with wind damage as the most common severe risk across northern Missouri, northern portions of Illinois/Indiana, into Lower Michigan. A more localized/pulse-type severe risk is anticipated farther southwest into southern Kansas/northwest Oklahoma. ...High Plains... Moderate instability will develop across parts of the northern/central High Plains this afternoon. Large-scale ascent will tend to be weak behind a departing mid-level shortwave trough. Even so, convective development should occur near the adjacent higher terrain this afternoon. Effective shear of 25-40 kt will support some updraft organization. Initially discrete cells may pose an isolated threat for hail. Some outflow amalgamation/mergers could eventually occur, with a threat of strong to locally severe gusts spreading eastward into the evening before convection eventually weakens. Farther south across portions of the southern High Plains, scattered to numerous thunderstorms are also expected to develop this afternoon/early evening. Deep-layer shear will remain weak across this region, but localized strong to severe outflow gusts may still be possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Thu Jul 24 2025 Valid 242000Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDWEST/GREAT LAKES... ...SUMMARY... Locally damaging thunderstorm wind gusts are possible from parts of the Great Lakes to the central and southern Plains this afternoon and evening. Isolated severe storms will also pose a risk of hail and severe wind gusts over portions of the northern and central High Plains. ...20z Update... The previous forecast largely remains on track. Thunderstorm development is underway across portions of northern IL, which should intensify and track into northern IN and southern MI through the evening hours. Severe hail/wind risk probabilities were reduced across far northern lower MI due to the recent passage of deep convection and an influx of cooler/lower theta-e air. See the previous discussion below as well as MCDs #1771 and #1772 for additional details. ..Moore.. 07/24/2025 .PREV DISCUSSION... /ISSUED 1134 AM CDT Thu Jul 24 2025/ ...Northern Lower Michigan... Ahead of an MCV, a well-organized cluster of storms will pose at a short-term severe risk across far northern Lower Michigan early this afternoon, although there is some potential for additional development southwestward along the front this afternoon. ...Midwest/Lake Michigan vicinity to south-central Plains... Aside from an MCV nearing northern Lake Michigan, at least one additional eastward-moving MCV exists across eastern Iowa, nearing the southwest Wisconsin/northwest Illinois border vicinity as of midday. Some multi-layer cloud debris still persists, and a pre-frontal veering of winds (westerly component) has occurred in some areas. However, heating of a very moist air mass (70s F surface dewpoints) will lead to strong destabilization (2500-4000 J/kg MLCAPE) and relatively weak boundary-layer inhibition this afternoon near/ahead of the front. Most 12z global guidance/HREF members are more aggressive in the coverage/intensity of convection than morning HRRR/RRFS/MPAS runs, particularly for northern portions of Illinois/Indiana into Lower Michigan. Where deep convection does develop/sustain this afternoon, MCV-aided enhancement of low/mid-tropospheric flow will support some well-organized bands/clusters of storms with wind damage as the most common severe risk across northern Missouri, northern portions of Illinois/Indiana, into Lower Michigan. A more localized/pulse-type severe risk is anticipated farther southwest into southern Kansas/northwest Oklahoma. ...High Plains... Moderate instability will develop across parts of the northern/central High Plains this afternoon. Large-scale ascent will tend to be weak behind a departing mid-level shortwave trough. Even so, convective development should occur near the adjacent higher terrain this afternoon. Effective shear of 25-40 kt will support some updraft organization. Initially discrete cells may pose an isolated threat for hail. Some outflow amalgamation/mergers could eventually occur, with a threat of strong to locally severe gusts spreading eastward into the evening before convection eventually weakens. Farther south across portions of the southern High Plains, scattered to numerous thunderstorms are also expected to develop this afternoon/early evening. Deep-layer shear will remain weak across this region, but localized strong to severe outflow gusts may still be possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Thu Jul 24 2025 Valid 242000Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDWEST/GREAT LAKES... ...SUMMARY... Locally damaging thunderstorm wind gusts are possible from parts of the Great Lakes to the central and southern Plains this afternoon and evening. Isolated severe storms will also pose a risk of hail and severe wind gusts over portions of the northern and central High Plains. ...20z Update... The previous forecast largely remains on track. Thunderstorm development is underway across portions of northern IL, which should intensify and track into northern IN and southern MI through the evening hours. Severe hail/wind risk probabilities were reduced across far northern lower MI due to the recent passage of deep convection and an influx of cooler/lower theta-e air. See the previous discussion below as well as MCDs #1771 and #1772 for additional details. ..Moore.. 07/24/2025 .PREV DISCUSSION... /ISSUED 1134 AM CDT Thu Jul 24 2025/ ...Northern Lower Michigan... Ahead of an MCV, a well-organized cluster of storms will pose at a short-term severe risk across far northern Lower Michigan early this afternoon, although there is some potential for additional development southwestward along the front this afternoon. ...Midwest/Lake Michigan vicinity to south-central Plains... Aside from an MCV nearing northern Lake Michigan, at least one additional eastward-moving MCV exists across eastern Iowa, nearing the southwest Wisconsin/northwest Illinois border vicinity as of midday. Some multi-layer cloud debris still persists, and a pre-frontal veering of winds (westerly component) has occurred in some areas. However, heating of a very moist air mass (70s F surface dewpoints) will lead to strong destabilization (2500-4000 J/kg MLCAPE) and relatively weak boundary-layer inhibition this afternoon near/ahead of the front. Most 12z global guidance/HREF members are more aggressive in the coverage/intensity of convection than morning HRRR/RRFS/MPAS runs, particularly for northern portions of Illinois/Indiana into Lower Michigan. Where deep convection does develop/sustain this afternoon, MCV-aided enhancement of low/mid-tropospheric flow will support some well-organized bands/clusters of storms with wind damage as the most common severe risk across northern Missouri, northern portions of Illinois/Indiana, into Lower Michigan. A more localized/pulse-type severe risk is anticipated farther southwest into southern Kansas/northwest Oklahoma. ...High Plains... Moderate instability will develop across parts of the northern/central High Plains this afternoon. Large-scale ascent will tend to be weak behind a departing mid-level shortwave trough. Even so, convective development should occur near the adjacent higher terrain this afternoon. Effective shear of 25-40 kt will support some updraft organization. Initially discrete cells may pose an isolated threat for hail. Some outflow amalgamation/mergers could eventually occur, with a threat of strong to locally severe gusts spreading eastward into the evening before convection eventually weakens. Farther south across portions of the southern High Plains, scattered to numerous thunderstorms are also expected to develop this afternoon/early evening. Deep-layer shear will remain weak across this region, but localized strong to severe outflow gusts may still be possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0252 PM CDT Thu Jul 24 2025 Valid 242000Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDWEST/GREAT LAKES... ...SUMMARY... Locally damaging thunderstorm wind gusts are possible from parts of the Great Lakes to the central and southern Plains this afternoon and evening. Isolated severe storms will also pose a risk of hail and severe wind gusts over portions of the northern and central High Plains. ...20z Update... The previous forecast largely remains on track. Thunderstorm development is underway across portions of northern IL, which should intensify and track into northern IN and southern MI through the evening hours. Severe hail/wind risk probabilities were reduced across far northern lower MI due to the recent passage of deep convection and an influx of cooler/lower theta-e air. See the previous discussion below as well as MCDs #1771 and #1772 for additional details. ..Moore.. 07/24/2025 .PREV DISCUSSION... /ISSUED 1134 AM CDT Thu Jul 24 2025/ ...Northern Lower Michigan... Ahead of an MCV, a well-organized cluster of storms will pose at a short-term severe risk across far northern Lower Michigan early this afternoon, although there is some potential for additional development southwestward along the front this afternoon. ...Midwest/Lake Michigan vicinity to south-central Plains... Aside from an MCV nearing northern Lake Michigan, at least one additional eastward-moving MCV exists across eastern Iowa, nearing the southwest Wisconsin/northwest Illinois border vicinity as of midday. Some multi-layer cloud debris still persists, and a pre-frontal veering of winds (westerly component) has occurred in some areas. However, heating of a very moist air mass (70s F surface dewpoints) will lead to strong destabilization (2500-4000 J/kg MLCAPE) and relatively weak boundary-layer inhibition this afternoon near/ahead of the front. Most 12z global guidance/HREF members are more aggressive in the coverage/intensity of convection than morning HRRR/RRFS/MPAS runs, particularly for northern portions of Illinois/Indiana into Lower Michigan. Where deep convection does develop/sustain this afternoon, MCV-aided enhancement of low/mid-tropospheric flow will support some well-organized bands/clusters of storms with wind damage as the most common severe risk across northern Missouri, northern portions of Illinois/Indiana, into Lower Michigan. A more localized/pulse-type severe risk is anticipated farther southwest into southern Kansas/northwest Oklahoma. ...High Plains... Moderate instability will develop across parts of the northern/central High Plains this afternoon. Large-scale ascent will tend to be weak behind a departing mid-level shortwave trough. Even so, convective development should occur near the adjacent higher terrain this afternoon. Effective shear of 25-40 kt will support some updraft organization. Initially discrete cells may pose an isolated threat for hail. Some outflow amalgamation/mergers could eventually occur, with a threat of strong to locally severe gusts spreading eastward into the evening before convection eventually weakens. Farther south across portions of the southern High Plains, scattered to numerous thunderstorms are also expected to develop this afternoon/early evening. Deep-layer shear will remain weak across this region, but localized strong to severe outflow gusts may still be possible. Read more