Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0217 AM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF CENTRAL AND EASTERN OREGON INTO EXTREME NORTHWEST NEVADA... ...Synopsis... Upper ridging will persist across the central and eastern CONUS while broad mid-level troughing remains in place along the West Coast tomorrow (Wednesday). Mid-level moisture will continue to pivot around the mid-level trough, toward the upper ridge, from the Pacific Northwest into the northern Rockies. An embedded mid-level impulse, accompanied by stronger flow aloft, will traverse the northwest Great Basin and move northwestward into the Pacific Northwest through the late afternoon to overnight period. As this occurs, enhanced lift will promote at least scattered thunderstorms over portions of the Pacific Northwest. Broad isolated dry-thunderstorm highlights are in place for areas that will experience lightning over dry fuels. Along and east of the Cascades, forecast soundings depict inverted-v thermodynamic profiles, which would support high-based, potentially fast-moving thunderstorms. These storms may pass over fuels receptive to fire spread, but with minimal rainfall accumulations given fast storm speeds. Given the potentially higher density of fast moving storms east of the Cascades, scattered dry thunderstorm highlights have been introduced for central and eastern Oregon into extreme northwest Nevada. ..Squitieri.. 07/29/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0140 AM CDT Tue Jul 29 2025 Valid 291200Z - 301200Z ...Synopsis... An upper ridge will persist across the CONUS today, with mid-level moisture poised to pivot around the western extent of the ridge over portions of the northwestern Great Basin into the Pacific Northwest. Here, high-based thunderstorms should develop atop a dry boundary layer, with a mix of wet and dry thunderstorms expected. Isolated dry thunderstorm highlights have been issued given the presence of dry fuels. ..Squitieri.. 07/29/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0140 AM CDT Tue Jul 29 2025 Valid 291200Z - 301200Z ...Synopsis... An upper ridge will persist across the CONUS today, with mid-level moisture poised to pivot around the western extent of the ridge over portions of the northwestern Great Basin into the Pacific Northwest. Here, high-based thunderstorms should develop atop a dry boundary layer, with a mix of wet and dry thunderstorms expected. Isolated dry thunderstorm highlights have been issued given the presence of dry fuels. ..Squitieri.. 07/29/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0140 AM CDT Tue Jul 29 2025 Valid 291200Z - 301200Z ...Synopsis... An upper ridge will persist across the CONUS today, with mid-level moisture poised to pivot around the western extent of the ridge over portions of the northwestern Great Basin into the Pacific Northwest. Here, high-based thunderstorms should develop atop a dry boundary layer, with a mix of wet and dry thunderstorms expected. Isolated dry thunderstorm highlights have been issued given the presence of dry fuels. ..Squitieri.. 07/29/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0140 AM CDT Tue Jul 29 2025 Valid 291200Z - 301200Z ...Synopsis... An upper ridge will persist across the CONUS today, with mid-level moisture poised to pivot around the western extent of the ridge over portions of the northwestern Great Basin into the Pacific Northwest. Here, high-based thunderstorms should develop atop a dry boundary layer, with a mix of wet and dry thunderstorms expected. Isolated dry thunderstorm highlights have been issued given the presence of dry fuels. ..Squitieri.. 07/29/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0140 AM CDT Tue Jul 29 2025 Valid 291200Z - 301200Z ...Synopsis... An upper ridge will persist across the CONUS today, with mid-level moisture poised to pivot around the western extent of the ridge over portions of the northwestern Great Basin into the Pacific Northwest. Here, high-based thunderstorms should develop atop a dry boundary layer, with a mix of wet and dry thunderstorms expected. Isolated dry thunderstorm highlights have been issued given the presence of dry fuels. ..Squitieri.. 07/29/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0140 AM CDT Tue Jul 29 2025 Valid 291200Z - 301200Z ...Synopsis... An upper ridge will persist across the CONUS today, with mid-level moisture poised to pivot around the western extent of the ridge over portions of the northwestern Great Basin into the Pacific Northwest. Here, high-based thunderstorms should develop atop a dry boundary layer, with a mix of wet and dry thunderstorms expected. Isolated dry thunderstorm highlights have been issued given the presence of dry fuels. ..Squitieri.. 07/29/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0140 AM CDT Tue Jul 29 2025 Valid 291200Z - 301200Z ...Synopsis... An upper ridge will persist across the CONUS today, with mid-level moisture poised to pivot around the western extent of the ridge over portions of the northwestern Great Basin into the Pacific Northwest. Here, high-based thunderstorms should develop atop a dry boundary layer, with a mix of wet and dry thunderstorms expected. Isolated dry thunderstorm highlights have been issued given the presence of dry fuels. ..Squitieri.. 07/29/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0140 AM CDT Tue Jul 29 2025 Valid 291200Z - 301200Z ...Synopsis... An upper ridge will persist across the CONUS today, with mid-level moisture poised to pivot around the western extent of the ridge over portions of the northwestern Great Basin into the Pacific Northwest. Here, high-based thunderstorms should develop atop a dry boundary layer, with a mix of wet and dry thunderstorms expected. Isolated dry thunderstorm highlights have been issued given the presence of dry fuels. ..Squitieri.. 07/29/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0555 Status Updates
STATUS REPORT ON WW 555 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 NNE DSM TO 35 ENE MCW. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1831. ..GRAMS..07/29/25 ATTN...WFO...ARX...DMX...DVN... STATUS REPORT FOR WS 555 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS IAC005-011-013-017-019-023-031-037-043-045-055-061-065-067-075- 083-089-095-097-099-103-105-107-113-127-131-157-171-183-191- 290740- IA . IOWA COUNTIES INCLUDED ARE ALLAMAKEE BENTON BLACK HAWK BREMER BUCHANAN BUTLER CEDAR CHICKASAW CLAYTON CLINTON DELAWARE DUBUQUE FAYETTE FLOYD GRUNDY HARDIN HOWARD IOWA JACKSON JASPER JOHNSON JONES KEOKUK LINN MARSHALL MITCHELL POWESHIEK TAMA WASHINGTON WINNESHIEK WIC023-043-081-103-123-290740- WI . WISCONSIN COUNTIES INCLUDED ARE Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1255 AM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL HIGH PLAINS AND FROM THE MIDWEST TO THE MID ATLANTIC AND NORTHEAST... ...SUMMARY... Severe thunderstorms are possible from the Mid-Missouri/Mississippi Valley vicinity to parts of the Mid-Atlantic/southern New England, and the northern/central High Plains on Wednesday. ...Central High Plains Vicinity... A mid-level shortwave trough will dig slowly southward across southern Montana and into northern Wyoming on Wednesday. South of this trough, mid-level flow will strengthen to around 30 knots amid moderate instability with steep mid-level lapse rates. Some supercells may be possible with a threat for large hail and severe wind gusts. The number of organized supercells is the primary question. At this time, it appears the threat may be relatively isolated. However, if more than a few organized supercells appear likely, greater probabilities may be needed. ...Midwest... Storms will likely be ongoing at the beginning of the period from northern Missouri into northern Illinois. As temperatures warm into the 80s with dewpoints in the 70s by late morning, moderate to strong instability is forecast with minimal inhibition. This should allow ongoing convection (or renewed development along residual outflow) to persist eastward through the day. The greatest threat will be along the frontal zone where mid-level lapse rates will be steeper and shear will be somewhat stronger. The narrow corridor of favorable overlap between the greatest shear and instability with questions about storm mode preclude higher probabilities at this time. ...Northeast... Hot temperatures will develop across the Northeast on Wednesday with moderate instability expected. Moderate mid-level flow will overspread this region along the southern periphery of a strong mid-level trough across southeastern Canada. This stronger shear may permit a few supercell storms with a threat for large hail. Elsewhere, isolated strong downburst winds amid the strong heating will be the primary threat. ..Bentley.. 07/29/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1255 AM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL HIGH PLAINS AND FROM THE MIDWEST TO THE MID ATLANTIC AND NORTHEAST... ...SUMMARY... Severe thunderstorms are possible from the Mid-Missouri/Mississippi Valley vicinity to parts of the Mid-Atlantic/southern New England, and the northern/central High Plains on Wednesday. ...Central High Plains Vicinity... A mid-level shortwave trough will dig slowly southward across southern Montana and into northern Wyoming on Wednesday. South of this trough, mid-level flow will strengthen to around 30 knots amid moderate instability with steep mid-level lapse rates. Some supercells may be possible with a threat for large hail and severe wind gusts. The number of organized supercells is the primary question. At this time, it appears the threat may be relatively isolated. However, if more than a few organized supercells appear likely, greater probabilities may be needed. ...Midwest... Storms will likely be ongoing at the beginning of the period from northern Missouri into northern Illinois. As temperatures warm into the 80s with dewpoints in the 70s by late morning, moderate to strong instability is forecast with minimal inhibition. This should allow ongoing convection (or renewed development along residual outflow) to persist eastward through the day. The greatest threat will be along the frontal zone where mid-level lapse rates will be steeper and shear will be somewhat stronger. The narrow corridor of favorable overlap between the greatest shear and instability with questions about storm mode preclude higher probabilities at this time. ...Northeast... Hot temperatures will develop across the Northeast on Wednesday with moderate instability expected. Moderate mid-level flow will overspread this region along the southern periphery of a strong mid-level trough across southeastern Canada. This stronger shear may permit a few supercell storms with a threat for large hail. Elsewhere, isolated strong downburst winds amid the strong heating will be the primary threat. ..Bentley.. 07/29/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1255 AM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL HIGH PLAINS AND FROM THE MIDWEST TO THE MID ATLANTIC AND NORTHEAST... ...SUMMARY... Severe thunderstorms are possible from the Mid-Missouri/Mississippi Valley vicinity to parts of the Mid-Atlantic/southern New England, and the northern/central High Plains on Wednesday. ...Central High Plains Vicinity... A mid-level shortwave trough will dig slowly southward across southern Montana and into northern Wyoming on Wednesday. South of this trough, mid-level flow will strengthen to around 30 knots amid moderate instability with steep mid-level lapse rates. Some supercells may be possible with a threat for large hail and severe wind gusts. The number of organized supercells is the primary question. At this time, it appears the threat may be relatively isolated. However, if more than a few organized supercells appear likely, greater probabilities may be needed. ...Midwest... Storms will likely be ongoing at the beginning of the period from northern Missouri into northern Illinois. As temperatures warm into the 80s with dewpoints in the 70s by late morning, moderate to strong instability is forecast with minimal inhibition. This should allow ongoing convection (or renewed development along residual outflow) to persist eastward through the day. The greatest threat will be along the frontal zone where mid-level lapse rates will be steeper and shear will be somewhat stronger. The narrow corridor of favorable overlap between the greatest shear and instability with questions about storm mode preclude higher probabilities at this time. ...Northeast... Hot temperatures will develop across the Northeast on Wednesday with moderate instability expected. Moderate mid-level flow will overspread this region along the southern periphery of a strong mid-level trough across southeastern Canada. This stronger shear may permit a few supercell storms with a threat for large hail. Elsewhere, isolated strong downburst winds amid the strong heating will be the primary threat. ..Bentley.. 07/29/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1255 AM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL HIGH PLAINS AND FROM THE MIDWEST TO THE MID ATLANTIC AND NORTHEAST... ...SUMMARY... Severe thunderstorms are possible from the Mid-Missouri/Mississippi Valley vicinity to parts of the Mid-Atlantic/southern New England, and the northern/central High Plains on Wednesday. ...Central High Plains Vicinity... A mid-level shortwave trough will dig slowly southward across southern Montana and into northern Wyoming on Wednesday. South of this trough, mid-level flow will strengthen to around 30 knots amid moderate instability with steep mid-level lapse rates. Some supercells may be possible with a threat for large hail and severe wind gusts. The number of organized supercells is the primary question. At this time, it appears the threat may be relatively isolated. However, if more than a few organized supercells appear likely, greater probabilities may be needed. ...Midwest... Storms will likely be ongoing at the beginning of the period from northern Missouri into northern Illinois. As temperatures warm into the 80s with dewpoints in the 70s by late morning, moderate to strong instability is forecast with minimal inhibition. This should allow ongoing convection (or renewed development along residual outflow) to persist eastward through the day. The greatest threat will be along the frontal zone where mid-level lapse rates will be steeper and shear will be somewhat stronger. The narrow corridor of favorable overlap between the greatest shear and instability with questions about storm mode preclude higher probabilities at this time. ...Northeast... Hot temperatures will develop across the Northeast on Wednesday with moderate instability expected. Moderate mid-level flow will overspread this region along the southern periphery of a strong mid-level trough across southeastern Canada. This stronger shear may permit a few supercell storms with a threat for large hail. Elsewhere, isolated strong downburst winds amid the strong heating will be the primary threat. ..Bentley.. 07/29/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1255 AM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL HIGH PLAINS AND FROM THE MIDWEST TO THE MID ATLANTIC AND NORTHEAST... ...SUMMARY... Severe thunderstorms are possible from the Mid-Missouri/Mississippi Valley vicinity to parts of the Mid-Atlantic/southern New England, and the northern/central High Plains on Wednesday. ...Central High Plains Vicinity... A mid-level shortwave trough will dig slowly southward across southern Montana and into northern Wyoming on Wednesday. South of this trough, mid-level flow will strengthen to around 30 knots amid moderate instability with steep mid-level lapse rates. Some supercells may be possible with a threat for large hail and severe wind gusts. The number of organized supercells is the primary question. At this time, it appears the threat may be relatively isolated. However, if more than a few organized supercells appear likely, greater probabilities may be needed. ...Midwest... Storms will likely be ongoing at the beginning of the period from northern Missouri into northern Illinois. As temperatures warm into the 80s with dewpoints in the 70s by late morning, moderate to strong instability is forecast with minimal inhibition. This should allow ongoing convection (or renewed development along residual outflow) to persist eastward through the day. The greatest threat will be along the frontal zone where mid-level lapse rates will be steeper and shear will be somewhat stronger. The narrow corridor of favorable overlap between the greatest shear and instability with questions about storm mode preclude higher probabilities at this time. ...Northeast... Hot temperatures will develop across the Northeast on Wednesday with moderate instability expected. Moderate mid-level flow will overspread this region along the southern periphery of a strong mid-level trough across southeastern Canada. This stronger shear may permit a few supercell storms with a threat for large hail. Elsewhere, isolated strong downburst winds amid the strong heating will be the primary threat. ..Bentley.. 07/29/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1255 AM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL HIGH PLAINS AND FROM THE MIDWEST TO THE MID ATLANTIC AND NORTHEAST... ...SUMMARY... Severe thunderstorms are possible from the Mid-Missouri/Mississippi Valley vicinity to parts of the Mid-Atlantic/southern New England, and the northern/central High Plains on Wednesday. ...Central High Plains Vicinity... A mid-level shortwave trough will dig slowly southward across southern Montana and into northern Wyoming on Wednesday. South of this trough, mid-level flow will strengthen to around 30 knots amid moderate instability with steep mid-level lapse rates. Some supercells may be possible with a threat for large hail and severe wind gusts. The number of organized supercells is the primary question. At this time, it appears the threat may be relatively isolated. However, if more than a few organized supercells appear likely, greater probabilities may be needed. ...Midwest... Storms will likely be ongoing at the beginning of the period from northern Missouri into northern Illinois. As temperatures warm into the 80s with dewpoints in the 70s by late morning, moderate to strong instability is forecast with minimal inhibition. This should allow ongoing convection (or renewed development along residual outflow) to persist eastward through the day. The greatest threat will be along the frontal zone where mid-level lapse rates will be steeper and shear will be somewhat stronger. The narrow corridor of favorable overlap between the greatest shear and instability with questions about storm mode preclude higher probabilities at this time. ...Northeast... Hot temperatures will develop across the Northeast on Wednesday with moderate instability expected. Moderate mid-level flow will overspread this region along the southern periphery of a strong mid-level trough across southeastern Canada. This stronger shear may permit a few supercell storms with a threat for large hail. Elsewhere, isolated strong downburst winds amid the strong heating will be the primary threat. ..Bentley.. 07/29/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1255 AM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL HIGH PLAINS AND FROM THE MIDWEST TO THE MID ATLANTIC AND NORTHEAST... ...SUMMARY... Severe thunderstorms are possible from the Mid-Missouri/Mississippi Valley vicinity to parts of the Mid-Atlantic/southern New England, and the northern/central High Plains on Wednesday. ...Central High Plains Vicinity... A mid-level shortwave trough will dig slowly southward across southern Montana and into northern Wyoming on Wednesday. South of this trough, mid-level flow will strengthen to around 30 knots amid moderate instability with steep mid-level lapse rates. Some supercells may be possible with a threat for large hail and severe wind gusts. The number of organized supercells is the primary question. At this time, it appears the threat may be relatively isolated. However, if more than a few organized supercells appear likely, greater probabilities may be needed. ...Midwest... Storms will likely be ongoing at the beginning of the period from northern Missouri into northern Illinois. As temperatures warm into the 80s with dewpoints in the 70s by late morning, moderate to strong instability is forecast with minimal inhibition. This should allow ongoing convection (or renewed development along residual outflow) to persist eastward through the day. The greatest threat will be along the frontal zone where mid-level lapse rates will be steeper and shear will be somewhat stronger. The narrow corridor of favorable overlap between the greatest shear and instability with questions about storm mode preclude higher probabilities at this time. ...Northeast... Hot temperatures will develop across the Northeast on Wednesday with moderate instability expected. Moderate mid-level flow will overspread this region along the southern periphery of a strong mid-level trough across southeastern Canada. This stronger shear may permit a few supercell storms with a threat for large hail. Elsewhere, isolated strong downburst winds amid the strong heating will be the primary threat. ..Bentley.. 07/29/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1255 AM CDT Tue Jul 29 2025 Valid 301200Z - 311200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL HIGH PLAINS AND FROM THE MIDWEST TO THE MID ATLANTIC AND NORTHEAST... ...SUMMARY... Severe thunderstorms are possible from the Mid-Missouri/Mississippi Valley vicinity to parts of the Mid-Atlantic/southern New England, and the northern/central High Plains on Wednesday. ...Central High Plains Vicinity... A mid-level shortwave trough will dig slowly southward across southern Montana and into northern Wyoming on Wednesday. South of this trough, mid-level flow will strengthen to around 30 knots amid moderate instability with steep mid-level lapse rates. Some supercells may be possible with a threat for large hail and severe wind gusts. The number of organized supercells is the primary question. At this time, it appears the threat may be relatively isolated. However, if more than a few organized supercells appear likely, greater probabilities may be needed. ...Midwest... Storms will likely be ongoing at the beginning of the period from northern Missouri into northern Illinois. As temperatures warm into the 80s with dewpoints in the 70s by late morning, moderate to strong instability is forecast with minimal inhibition. This should allow ongoing convection (or renewed development along residual outflow) to persist eastward through the day. The greatest threat will be along the frontal zone where mid-level lapse rates will be steeper and shear will be somewhat stronger. The narrow corridor of favorable overlap between the greatest shear and instability with questions about storm mode preclude higher probabilities at this time. ...Northeast... Hot temperatures will develop across the Northeast on Wednesday with moderate instability expected. Moderate mid-level flow will overspread this region along the southern periphery of a strong mid-level trough across southeastern Canada. This stronger shear may permit a few supercell storms with a threat for large hail. Elsewhere, isolated strong downburst winds amid the strong heating will be the primary threat. ..Bentley.. 07/29/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0111 AM CDT Tue Jul 29 2025 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN MONTANA ACROSS EASTERN WYOMING...NEBRASKA...AND INTO WESTERN IOWA... ...SUMMARY... Severe thunderstorms are expected from southern Montana into the central High Plains, and across much of Nebraska and western Iowa. Areas of damaging winds will be possible, with hail most likely over western areas. ...Much of NE into IA... A cold front is likely to extend from northeast Co into northern NE and IA during the afternoon, while low pressure develops over western KS. Winds aloft will be relatively weak at these latitudes, only averaging near 15-20 kt. Winds below 500 mb will also be relatively weak, except for within the deeply mixed boundary layer with gusty south winds. Indications are that thunderstorms will develop by late afternoon across eastern CO and western NE, with increasing coverage and vigor near the stalled front across NE and into northern IA. Models indicate numerous storms during the evening, with a general eastward propagation. Given such weak winds below 500 mb, it appears widespread and potentially shorter lived convection will be possible. However, an eventual aggregation into an MCS is expected, which could yield greater overall coverage of strong to severe gusts. Isolated significant gusts cannot be ruled out as storms move into the strongly heated air mass/deeply mixed boundary layer. ...MT into WY... High pressure will exist over southern Canada with northeast surface winds across much of the northern Plains. Dewpoints in the 50s to near 60 F will remain with in this air mass from eastern MT into WY, and daytime heating will yield MUCAPE over 2000 J/kg by afternoon. Cool temperatures aloft will exist in the mid and upper levels, along with 20-30 kt westerlies. Storms will form over the higher terrain during the late afternoon, aided by upslope flow. Given the backed low-level wind fields, sufficient shear will favor large hail, perhaps into the 1.75 to 2.00" range in the strongest cells. Locally damaging gusts will also be likely. ..Jewell/Squitieri.. 07/29/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0111 AM CDT Tue Jul 29 2025 Valid 291200Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN MONTANA ACROSS EASTERN WYOMING...NEBRASKA...AND INTO WESTERN IOWA... ...SUMMARY... Severe thunderstorms are expected from southern Montana into the central High Plains, and across much of Nebraska and western Iowa. Areas of damaging winds will be possible, with hail most likely over western areas. ...Much of NE into IA... A cold front is likely to extend from northeast Co into northern NE and IA during the afternoon, while low pressure develops over western KS. Winds aloft will be relatively weak at these latitudes, only averaging near 15-20 kt. Winds below 500 mb will also be relatively weak, except for within the deeply mixed boundary layer with gusty south winds. Indications are that thunderstorms will develop by late afternoon across eastern CO and western NE, with increasing coverage and vigor near the stalled front across NE and into northern IA. Models indicate numerous storms during the evening, with a general eastward propagation. Given such weak winds below 500 mb, it appears widespread and potentially shorter lived convection will be possible. However, an eventual aggregation into an MCS is expected, which could yield greater overall coverage of strong to severe gusts. Isolated significant gusts cannot be ruled out as storms move into the strongly heated air mass/deeply mixed boundary layer. ...MT into WY... High pressure will exist over southern Canada with northeast surface winds across much of the northern Plains. Dewpoints in the 50s to near 60 F will remain with in this air mass from eastern MT into WY, and daytime heating will yield MUCAPE over 2000 J/kg by afternoon. Cool temperatures aloft will exist in the mid and upper levels, along with 20-30 kt westerlies. Storms will form over the higher terrain during the late afternoon, aided by upslope flow. Given the backed low-level wind fields, sufficient shear will favor large hail, perhaps into the 1.75 to 2.00" range in the strongest cells. Locally damaging gusts will also be likely. ..Jewell/Squitieri.. 07/29/2025 Read more