Severe Storms

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jun 29 2025 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY...AND OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Isolated to scattered strong to severe thunderstorms are possible from the upper Great Lakes into the central High Plains. Wind is the primary risk, though hail is expected across portions of the High Plains. ...20Z Update... The Slight risk was expanded southeastward from parts of the central Plains into the Middle MS Valley, where a cluster of thunderstorms is intensifying as it impinges on a strongly unstable air mass. The primary concern with this activity is damaging wind gusts. For information on the severe risk here, reference Severe Thunderstorm Watch 478. Additionally, 2-percent tornado probabilities were added along this corridor and westward into southeast/south-central KS and far northeast/north-central OK. Here, antecedent outflow is diurnally destabilizing amid rich boundary-layer moisture. Clockwise-curved low-level hodographs will support a localized tornado risk with any cells that can develop in this corridor. Farther west, significant-wind probabilities were added over northwest KS, southwest NE, and far eastern CO. Any thunderstorm clusters that evolve out of CO and move through this area will have the potential of producing gusts upward of 75 mph -- aided by steep deep-layer lapse rates and sufficiently elongated hodographs. Additionally, visible satellite imagery shows a shallow boundary-layer cumulus field along a surface wind shift in this general area. As storms move into this area of enhanced moisture and steep lapse rates, a brief tornado will be possible. Reference Severe Thunderstorm Watch 477 and MCD 1508 for the severe risk in the Upper Midwest, and MCDs 1509 and 1510 for the High Plains severe risk. ..Weinman.. 06/29/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Jun 29 2025/ ...Eastern KS/Western MO... An overnight MCS is slowly weakening over central MO, with an associated outflow boundary extending from eastern KS into south-central MO. Strong heating will occur along and south of the boundary, where several 12z CAM solutions indicate development of afternoon thunderstorms. Given this scenario, have extended the SLGT risk farther south into this region. Locally damaging wind gusts would be the main concern. Refer to MCD #1506 for further short-term details. ...WY/CO/SD/NE... A low-amplitude shortwave trough is digging into WY. As forcing associated with this system overspreads the High Plains of WY, high-based convection is expected. Thunderstorms will intensify as they track into a moderately unstable air mass and weak but backed low-level flow. Severe storms capable of large hail and damaging winds may affect the Black Hills region and southward into the NE Panhandle. Storms will also develop southward into the foothills of CO this afternoon and spread eastward. Winds and temperatures aloft are less favorable for organized/severe storms that far south, but at least isolated instances of large hail and damaging winds are possible. ...IA/WI... Strong heating is occurring across much of WI today, where a moist air mass will lead to moderate CAPE values. Thunderstorms will develop by mid-afternoon along a remnant weak boundary across central WI/northeast IA and spread northeastward through the day. Vertical shear is not particularly strong, and overall convective organization is expected to be low. Nevertheless, steep low-level lapse rates and ample instability will promote strong downdrafts and some hail in the strongest cells. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jun 29 2025 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY...AND OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Isolated to scattered strong to severe thunderstorms are possible from the upper Great Lakes into the central High Plains. Wind is the primary risk, though hail is expected across portions of the High Plains. ...20Z Update... The Slight risk was expanded southeastward from parts of the central Plains into the Middle MS Valley, where a cluster of thunderstorms is intensifying as it impinges on a strongly unstable air mass. The primary concern with this activity is damaging wind gusts. For information on the severe risk here, reference Severe Thunderstorm Watch 478. Additionally, 2-percent tornado probabilities were added along this corridor and westward into southeast/south-central KS and far northeast/north-central OK. Here, antecedent outflow is diurnally destabilizing amid rich boundary-layer moisture. Clockwise-curved low-level hodographs will support a localized tornado risk with any cells that can develop in this corridor. Farther west, significant-wind probabilities were added over northwest KS, southwest NE, and far eastern CO. Any thunderstorm clusters that evolve out of CO and move through this area will have the potential of producing gusts upward of 75 mph -- aided by steep deep-layer lapse rates and sufficiently elongated hodographs. Additionally, visible satellite imagery shows a shallow boundary-layer cumulus field along a surface wind shift in this general area. As storms move into this area of enhanced moisture and steep lapse rates, a brief tornado will be possible. Reference Severe Thunderstorm Watch 477 and MCD 1508 for the severe risk in the Upper Midwest, and MCDs 1509 and 1510 for the High Plains severe risk. ..Weinman.. 06/29/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Jun 29 2025/ ...Eastern KS/Western MO... An overnight MCS is slowly weakening over central MO, with an associated outflow boundary extending from eastern KS into south-central MO. Strong heating will occur along and south of the boundary, where several 12z CAM solutions indicate development of afternoon thunderstorms. Given this scenario, have extended the SLGT risk farther south into this region. Locally damaging wind gusts would be the main concern. Refer to MCD #1506 for further short-term details. ...WY/CO/SD/NE... A low-amplitude shortwave trough is digging into WY. As forcing associated with this system overspreads the High Plains of WY, high-based convection is expected. Thunderstorms will intensify as they track into a moderately unstable air mass and weak but backed low-level flow. Severe storms capable of large hail and damaging winds may affect the Black Hills region and southward into the NE Panhandle. Storms will also develop southward into the foothills of CO this afternoon and spread eastward. Winds and temperatures aloft are less favorable for organized/severe storms that far south, but at least isolated instances of large hail and damaging winds are possible. ...IA/WI... Strong heating is occurring across much of WI today, where a moist air mass will lead to moderate CAPE values. Thunderstorms will develop by mid-afternoon along a remnant weak boundary across central WI/northeast IA and spread northeastward through the day. Vertical shear is not particularly strong, and overall convective organization is expected to be low. Nevertheless, steep low-level lapse rates and ample instability will promote strong downdrafts and some hail in the strongest cells. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jun 29 2025 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY...AND OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Isolated to scattered strong to severe thunderstorms are possible from the upper Great Lakes into the central High Plains. Wind is the primary risk, though hail is expected across portions of the High Plains. ...20Z Update... The Slight risk was expanded southeastward from parts of the central Plains into the Middle MS Valley, where a cluster of thunderstorms is intensifying as it impinges on a strongly unstable air mass. The primary concern with this activity is damaging wind gusts. For information on the severe risk here, reference Severe Thunderstorm Watch 478. Additionally, 2-percent tornado probabilities were added along this corridor and westward into southeast/south-central KS and far northeast/north-central OK. Here, antecedent outflow is diurnally destabilizing amid rich boundary-layer moisture. Clockwise-curved low-level hodographs will support a localized tornado risk with any cells that can develop in this corridor. Farther west, significant-wind probabilities were added over northwest KS, southwest NE, and far eastern CO. Any thunderstorm clusters that evolve out of CO and move through this area will have the potential of producing gusts upward of 75 mph -- aided by steep deep-layer lapse rates and sufficiently elongated hodographs. Additionally, visible satellite imagery shows a shallow boundary-layer cumulus field along a surface wind shift in this general area. As storms move into this area of enhanced moisture and steep lapse rates, a brief tornado will be possible. Reference Severe Thunderstorm Watch 477 and MCD 1508 for the severe risk in the Upper Midwest, and MCDs 1509 and 1510 for the High Plains severe risk. ..Weinman.. 06/29/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Jun 29 2025/ ...Eastern KS/Western MO... An overnight MCS is slowly weakening over central MO, with an associated outflow boundary extending from eastern KS into south-central MO. Strong heating will occur along and south of the boundary, where several 12z CAM solutions indicate development of afternoon thunderstorms. Given this scenario, have extended the SLGT risk farther south into this region. Locally damaging wind gusts would be the main concern. Refer to MCD #1506 for further short-term details. ...WY/CO/SD/NE... A low-amplitude shortwave trough is digging into WY. As forcing associated with this system overspreads the High Plains of WY, high-based convection is expected. Thunderstorms will intensify as they track into a moderately unstable air mass and weak but backed low-level flow. Severe storms capable of large hail and damaging winds may affect the Black Hills region and southward into the NE Panhandle. Storms will also develop southward into the foothills of CO this afternoon and spread eastward. Winds and temperatures aloft are less favorable for organized/severe storms that far south, but at least isolated instances of large hail and damaging winds are possible. ...IA/WI... Strong heating is occurring across much of WI today, where a moist air mass will lead to moderate CAPE values. Thunderstorms will develop by mid-afternoon along a remnant weak boundary across central WI/northeast IA and spread northeastward through the day. Vertical shear is not particularly strong, and overall convective organization is expected to be low. Nevertheless, steep low-level lapse rates and ample instability will promote strong downdrafts and some hail in the strongest cells. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jun 29 2025 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY...AND OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Isolated to scattered strong to severe thunderstorms are possible from the upper Great Lakes into the central High Plains. Wind is the primary risk, though hail is expected across portions of the High Plains. ...20Z Update... The Slight risk was expanded southeastward from parts of the central Plains into the Middle MS Valley, where a cluster of thunderstorms is intensifying as it impinges on a strongly unstable air mass. The primary concern with this activity is damaging wind gusts. For information on the severe risk here, reference Severe Thunderstorm Watch 478. Additionally, 2-percent tornado probabilities were added along this corridor and westward into southeast/south-central KS and far northeast/north-central OK. Here, antecedent outflow is diurnally destabilizing amid rich boundary-layer moisture. Clockwise-curved low-level hodographs will support a localized tornado risk with any cells that can develop in this corridor. Farther west, significant-wind probabilities were added over northwest KS, southwest NE, and far eastern CO. Any thunderstorm clusters that evolve out of CO and move through this area will have the potential of producing gusts upward of 75 mph -- aided by steep deep-layer lapse rates and sufficiently elongated hodographs. Additionally, visible satellite imagery shows a shallow boundary-layer cumulus field along a surface wind shift in this general area. As storms move into this area of enhanced moisture and steep lapse rates, a brief tornado will be possible. Reference Severe Thunderstorm Watch 477 and MCD 1508 for the severe risk in the Upper Midwest, and MCDs 1509 and 1510 for the High Plains severe risk. ..Weinman.. 06/29/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Jun 29 2025/ ...Eastern KS/Western MO... An overnight MCS is slowly weakening over central MO, with an associated outflow boundary extending from eastern KS into south-central MO. Strong heating will occur along and south of the boundary, where several 12z CAM solutions indicate development of afternoon thunderstorms. Given this scenario, have extended the SLGT risk farther south into this region. Locally damaging wind gusts would be the main concern. Refer to MCD #1506 for further short-term details. ...WY/CO/SD/NE... A low-amplitude shortwave trough is digging into WY. As forcing associated with this system overspreads the High Plains of WY, high-based convection is expected. Thunderstorms will intensify as they track into a moderately unstable air mass and weak but backed low-level flow. Severe storms capable of large hail and damaging winds may affect the Black Hills region and southward into the NE Panhandle. Storms will also develop southward into the foothills of CO this afternoon and spread eastward. Winds and temperatures aloft are less favorable for organized/severe storms that far south, but at least isolated instances of large hail and damaging winds are possible. ...IA/WI... Strong heating is occurring across much of WI today, where a moist air mass will lead to moderate CAPE values. Thunderstorms will develop by mid-afternoon along a remnant weak boundary across central WI/northeast IA and spread northeastward through the day. Vertical shear is not particularly strong, and overall convective organization is expected to be low. Nevertheless, steep low-level lapse rates and ample instability will promote strong downdrafts and some hail in the strongest cells. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jun 29 2025 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY...AND OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Isolated to scattered strong to severe thunderstorms are possible from the upper Great Lakes into the central High Plains. Wind is the primary risk, though hail is expected across portions of the High Plains. ...20Z Update... The Slight risk was expanded southeastward from parts of the central Plains into the Middle MS Valley, where a cluster of thunderstorms is intensifying as it impinges on a strongly unstable air mass. The primary concern with this activity is damaging wind gusts. For information on the severe risk here, reference Severe Thunderstorm Watch 478. Additionally, 2-percent tornado probabilities were added along this corridor and westward into southeast/south-central KS and far northeast/north-central OK. Here, antecedent outflow is diurnally destabilizing amid rich boundary-layer moisture. Clockwise-curved low-level hodographs will support a localized tornado risk with any cells that can develop in this corridor. Farther west, significant-wind probabilities were added over northwest KS, southwest NE, and far eastern CO. Any thunderstorm clusters that evolve out of CO and move through this area will have the potential of producing gusts upward of 75 mph -- aided by steep deep-layer lapse rates and sufficiently elongated hodographs. Additionally, visible satellite imagery shows a shallow boundary-layer cumulus field along a surface wind shift in this general area. As storms move into this area of enhanced moisture and steep lapse rates, a brief tornado will be possible. Reference Severe Thunderstorm Watch 477 and MCD 1508 for the severe risk in the Upper Midwest, and MCDs 1509 and 1510 for the High Plains severe risk. ..Weinman.. 06/29/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Jun 29 2025/ ...Eastern KS/Western MO... An overnight MCS is slowly weakening over central MO, with an associated outflow boundary extending from eastern KS into south-central MO. Strong heating will occur along and south of the boundary, where several 12z CAM solutions indicate development of afternoon thunderstorms. Given this scenario, have extended the SLGT risk farther south into this region. Locally damaging wind gusts would be the main concern. Refer to MCD #1506 for further short-term details. ...WY/CO/SD/NE... A low-amplitude shortwave trough is digging into WY. As forcing associated with this system overspreads the High Plains of WY, high-based convection is expected. Thunderstorms will intensify as they track into a moderately unstable air mass and weak but backed low-level flow. Severe storms capable of large hail and damaging winds may affect the Black Hills region and southward into the NE Panhandle. Storms will also develop southward into the foothills of CO this afternoon and spread eastward. Winds and temperatures aloft are less favorable for organized/severe storms that far south, but at least isolated instances of large hail and damaging winds are possible. ...IA/WI... Strong heating is occurring across much of WI today, where a moist air mass will lead to moderate CAPE values. Thunderstorms will develop by mid-afternoon along a remnant weak boundary across central WI/northeast IA and spread northeastward through the day. Vertical shear is not particularly strong, and overall convective organization is expected to be low. Nevertheless, steep low-level lapse rates and ample instability will promote strong downdrafts and some hail in the strongest cells. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jun 29 2025 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY...AND OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Isolated to scattered strong to severe thunderstorms are possible from the upper Great Lakes into the central High Plains. Wind is the primary risk, though hail is expected across portions of the High Plains. ...20Z Update... The Slight risk was expanded southeastward from parts of the central Plains into the Middle MS Valley, where a cluster of thunderstorms is intensifying as it impinges on a strongly unstable air mass. The primary concern with this activity is damaging wind gusts. For information on the severe risk here, reference Severe Thunderstorm Watch 478. Additionally, 2-percent tornado probabilities were added along this corridor and westward into southeast/south-central KS and far northeast/north-central OK. Here, antecedent outflow is diurnally destabilizing amid rich boundary-layer moisture. Clockwise-curved low-level hodographs will support a localized tornado risk with any cells that can develop in this corridor. Farther west, significant-wind probabilities were added over northwest KS, southwest NE, and far eastern CO. Any thunderstorm clusters that evolve out of CO and move through this area will have the potential of producing gusts upward of 75 mph -- aided by steep deep-layer lapse rates and sufficiently elongated hodographs. Additionally, visible satellite imagery shows a shallow boundary-layer cumulus field along a surface wind shift in this general area. As storms move into this area of enhanced moisture and steep lapse rates, a brief tornado will be possible. Reference Severe Thunderstorm Watch 477 and MCD 1508 for the severe risk in the Upper Midwest, and MCDs 1509 and 1510 for the High Plains severe risk. ..Weinman.. 06/29/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Jun 29 2025/ ...Eastern KS/Western MO... An overnight MCS is slowly weakening over central MO, with an associated outflow boundary extending from eastern KS into south-central MO. Strong heating will occur along and south of the boundary, where several 12z CAM solutions indicate development of afternoon thunderstorms. Given this scenario, have extended the SLGT risk farther south into this region. Locally damaging wind gusts would be the main concern. Refer to MCD #1506 for further short-term details. ...WY/CO/SD/NE... A low-amplitude shortwave trough is digging into WY. As forcing associated with this system overspreads the High Plains of WY, high-based convection is expected. Thunderstorms will intensify as they track into a moderately unstable air mass and weak but backed low-level flow. Severe storms capable of large hail and damaging winds may affect the Black Hills region and southward into the NE Panhandle. Storms will also develop southward into the foothills of CO this afternoon and spread eastward. Winds and temperatures aloft are less favorable for organized/severe storms that far south, but at least isolated instances of large hail and damaging winds are possible. ...IA/WI... Strong heating is occurring across much of WI today, where a moist air mass will lead to moderate CAPE values. Thunderstorms will develop by mid-afternoon along a remnant weak boundary across central WI/northeast IA and spread northeastward through the day. Vertical shear is not particularly strong, and overall convective organization is expected to be low. Nevertheless, steep low-level lapse rates and ample instability will promote strong downdrafts and some hail in the strongest cells. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jun 29 2025 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY...AND OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Isolated to scattered strong to severe thunderstorms are possible from the upper Great Lakes into the central High Plains. Wind is the primary risk, though hail is expected across portions of the High Plains. ...20Z Update... The Slight risk was expanded southeastward from parts of the central Plains into the Middle MS Valley, where a cluster of thunderstorms is intensifying as it impinges on a strongly unstable air mass. The primary concern with this activity is damaging wind gusts. For information on the severe risk here, reference Severe Thunderstorm Watch 478. Additionally, 2-percent tornado probabilities were added along this corridor and westward into southeast/south-central KS and far northeast/north-central OK. Here, antecedent outflow is diurnally destabilizing amid rich boundary-layer moisture. Clockwise-curved low-level hodographs will support a localized tornado risk with any cells that can develop in this corridor. Farther west, significant-wind probabilities were added over northwest KS, southwest NE, and far eastern CO. Any thunderstorm clusters that evolve out of CO and move through this area will have the potential of producing gusts upward of 75 mph -- aided by steep deep-layer lapse rates and sufficiently elongated hodographs. Additionally, visible satellite imagery shows a shallow boundary-layer cumulus field along a surface wind shift in this general area. As storms move into this area of enhanced moisture and steep lapse rates, a brief tornado will be possible. Reference Severe Thunderstorm Watch 477 and MCD 1508 for the severe risk in the Upper Midwest, and MCDs 1509 and 1510 for the High Plains severe risk. ..Weinman.. 06/29/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Jun 29 2025/ ...Eastern KS/Western MO... An overnight MCS is slowly weakening over central MO, with an associated outflow boundary extending from eastern KS into south-central MO. Strong heating will occur along and south of the boundary, where several 12z CAM solutions indicate development of afternoon thunderstorms. Given this scenario, have extended the SLGT risk farther south into this region. Locally damaging wind gusts would be the main concern. Refer to MCD #1506 for further short-term details. ...WY/CO/SD/NE... A low-amplitude shortwave trough is digging into WY. As forcing associated with this system overspreads the High Plains of WY, high-based convection is expected. Thunderstorms will intensify as they track into a moderately unstable air mass and weak but backed low-level flow. Severe storms capable of large hail and damaging winds may affect the Black Hills region and southward into the NE Panhandle. Storms will also develop southward into the foothills of CO this afternoon and spread eastward. Winds and temperatures aloft are less favorable for organized/severe storms that far south, but at least isolated instances of large hail and damaging winds are possible. ...IA/WI... Strong heating is occurring across much of WI today, where a moist air mass will lead to moderate CAPE values. Thunderstorms will develop by mid-afternoon along a remnant weak boundary across central WI/northeast IA and spread northeastward through the day. Vertical shear is not particularly strong, and overall convective organization is expected to be low. Nevertheless, steep low-level lapse rates and ample instability will promote strong downdrafts and some hail in the strongest cells. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jun 29 2025 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY...AND OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Isolated to scattered strong to severe thunderstorms are possible from the upper Great Lakes into the central High Plains. Wind is the primary risk, though hail is expected across portions of the High Plains. ...20Z Update... The Slight risk was expanded southeastward from parts of the central Plains into the Middle MS Valley, where a cluster of thunderstorms is intensifying as it impinges on a strongly unstable air mass. The primary concern with this activity is damaging wind gusts. For information on the severe risk here, reference Severe Thunderstorm Watch 478. Additionally, 2-percent tornado probabilities were added along this corridor and westward into southeast/south-central KS and far northeast/north-central OK. Here, antecedent outflow is diurnally destabilizing amid rich boundary-layer moisture. Clockwise-curved low-level hodographs will support a localized tornado risk with any cells that can develop in this corridor. Farther west, significant-wind probabilities were added over northwest KS, southwest NE, and far eastern CO. Any thunderstorm clusters that evolve out of CO and move through this area will have the potential of producing gusts upward of 75 mph -- aided by steep deep-layer lapse rates and sufficiently elongated hodographs. Additionally, visible satellite imagery shows a shallow boundary-layer cumulus field along a surface wind shift in this general area. As storms move into this area of enhanced moisture and steep lapse rates, a brief tornado will be possible. Reference Severe Thunderstorm Watch 477 and MCD 1508 for the severe risk in the Upper Midwest, and MCDs 1509 and 1510 for the High Plains severe risk. ..Weinman.. 06/29/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Jun 29 2025/ ...Eastern KS/Western MO... An overnight MCS is slowly weakening over central MO, with an associated outflow boundary extending from eastern KS into south-central MO. Strong heating will occur along and south of the boundary, where several 12z CAM solutions indicate development of afternoon thunderstorms. Given this scenario, have extended the SLGT risk farther south into this region. Locally damaging wind gusts would be the main concern. Refer to MCD #1506 for further short-term details. ...WY/CO/SD/NE... A low-amplitude shortwave trough is digging into WY. As forcing associated with this system overspreads the High Plains of WY, high-based convection is expected. Thunderstorms will intensify as they track into a moderately unstable air mass and weak but backed low-level flow. Severe storms capable of large hail and damaging winds may affect the Black Hills region and southward into the NE Panhandle. Storms will also develop southward into the foothills of CO this afternoon and spread eastward. Winds and temperatures aloft are less favorable for organized/severe storms that far south, but at least isolated instances of large hail and damaging winds are possible. ...IA/WI... Strong heating is occurring across much of WI today, where a moist air mass will lead to moderate CAPE values. Thunderstorms will develop by mid-afternoon along a remnant weak boundary across central WI/northeast IA and spread northeastward through the day. Vertical shear is not particularly strong, and overall convective organization is expected to be low. Nevertheless, steep low-level lapse rates and ample instability will promote strong downdrafts and some hail in the strongest cells. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jun 29 2025 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY...AND OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Isolated to scattered strong to severe thunderstorms are possible from the upper Great Lakes into the central High Plains. Wind is the primary risk, though hail is expected across portions of the High Plains. ...20Z Update... The Slight risk was expanded southeastward from parts of the central Plains into the Middle MS Valley, where a cluster of thunderstorms is intensifying as it impinges on a strongly unstable air mass. The primary concern with this activity is damaging wind gusts. For information on the severe risk here, reference Severe Thunderstorm Watch 478. Additionally, 2-percent tornado probabilities were added along this corridor and westward into southeast/south-central KS and far northeast/north-central OK. Here, antecedent outflow is diurnally destabilizing amid rich boundary-layer moisture. Clockwise-curved low-level hodographs will support a localized tornado risk with any cells that can develop in this corridor. Farther west, significant-wind probabilities were added over northwest KS, southwest NE, and far eastern CO. Any thunderstorm clusters that evolve out of CO and move through this area will have the potential of producing gusts upward of 75 mph -- aided by steep deep-layer lapse rates and sufficiently elongated hodographs. Additionally, visible satellite imagery shows a shallow boundary-layer cumulus field along a surface wind shift in this general area. As storms move into this area of enhanced moisture and steep lapse rates, a brief tornado will be possible. Reference Severe Thunderstorm Watch 477 and MCD 1508 for the severe risk in the Upper Midwest, and MCDs 1509 and 1510 for the High Plains severe risk. ..Weinman.. 06/29/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Jun 29 2025/ ...Eastern KS/Western MO... An overnight MCS is slowly weakening over central MO, with an associated outflow boundary extending from eastern KS into south-central MO. Strong heating will occur along and south of the boundary, where several 12z CAM solutions indicate development of afternoon thunderstorms. Given this scenario, have extended the SLGT risk farther south into this region. Locally damaging wind gusts would be the main concern. Refer to MCD #1506 for further short-term details. ...WY/CO/SD/NE... A low-amplitude shortwave trough is digging into WY. As forcing associated with this system overspreads the High Plains of WY, high-based convection is expected. Thunderstorms will intensify as they track into a moderately unstable air mass and weak but backed low-level flow. Severe storms capable of large hail and damaging winds may affect the Black Hills region and southward into the NE Panhandle. Storms will also develop southward into the foothills of CO this afternoon and spread eastward. Winds and temperatures aloft are less favorable for organized/severe storms that far south, but at least isolated instances of large hail and damaging winds are possible. ...IA/WI... Strong heating is occurring across much of WI today, where a moist air mass will lead to moderate CAPE values. Thunderstorms will develop by mid-afternoon along a remnant weak boundary across central WI/northeast IA and spread northeastward through the day. Vertical shear is not particularly strong, and overall convective organization is expected to be low. Nevertheless, steep low-level lapse rates and ample instability will promote strong downdrafts and some hail in the strongest cells. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jun 29 2025 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY...AND OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Isolated to scattered strong to severe thunderstorms are possible from the upper Great Lakes into the central High Plains. Wind is the primary risk, though hail is expected across portions of the High Plains. ...20Z Update... The Slight risk was expanded southeastward from parts of the central Plains into the Middle MS Valley, where a cluster of thunderstorms is intensifying as it impinges on a strongly unstable air mass. The primary concern with this activity is damaging wind gusts. For information on the severe risk here, reference Severe Thunderstorm Watch 478. Additionally, 2-percent tornado probabilities were added along this corridor and westward into southeast/south-central KS and far northeast/north-central OK. Here, antecedent outflow is diurnally destabilizing amid rich boundary-layer moisture. Clockwise-curved low-level hodographs will support a localized tornado risk with any cells that can develop in this corridor. Farther west, significant-wind probabilities were added over northwest KS, southwest NE, and far eastern CO. Any thunderstorm clusters that evolve out of CO and move through this area will have the potential of producing gusts upward of 75 mph -- aided by steep deep-layer lapse rates and sufficiently elongated hodographs. Additionally, visible satellite imagery shows a shallow boundary-layer cumulus field along a surface wind shift in this general area. As storms move into this area of enhanced moisture and steep lapse rates, a brief tornado will be possible. Reference Severe Thunderstorm Watch 477 and MCD 1508 for the severe risk in the Upper Midwest, and MCDs 1509 and 1510 for the High Plains severe risk. ..Weinman.. 06/29/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Jun 29 2025/ ...Eastern KS/Western MO... An overnight MCS is slowly weakening over central MO, with an associated outflow boundary extending from eastern KS into south-central MO. Strong heating will occur along and south of the boundary, where several 12z CAM solutions indicate development of afternoon thunderstorms. Given this scenario, have extended the SLGT risk farther south into this region. Locally damaging wind gusts would be the main concern. Refer to MCD #1506 for further short-term details. ...WY/CO/SD/NE... A low-amplitude shortwave trough is digging into WY. As forcing associated with this system overspreads the High Plains of WY, high-based convection is expected. Thunderstorms will intensify as they track into a moderately unstable air mass and weak but backed low-level flow. Severe storms capable of large hail and damaging winds may affect the Black Hills region and southward into the NE Panhandle. Storms will also develop southward into the foothills of CO this afternoon and spread eastward. Winds and temperatures aloft are less favorable for organized/severe storms that far south, but at least isolated instances of large hail and damaging winds are possible. ...IA/WI... Strong heating is occurring across much of WI today, where a moist air mass will lead to moderate CAPE values. Thunderstorms will develop by mid-afternoon along a remnant weak boundary across central WI/northeast IA and spread northeastward through the day. Vertical shear is not particularly strong, and overall convective organization is expected to be low. Nevertheless, steep low-level lapse rates and ample instability will promote strong downdrafts and some hail in the strongest cells. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jun 29 2025 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY...AND OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Isolated to scattered strong to severe thunderstorms are possible from the upper Great Lakes into the central High Plains. Wind is the primary risk, though hail is expected across portions of the High Plains. ...20Z Update... The Slight risk was expanded southeastward from parts of the central Plains into the Middle MS Valley, where a cluster of thunderstorms is intensifying as it impinges on a strongly unstable air mass. The primary concern with this activity is damaging wind gusts. For information on the severe risk here, reference Severe Thunderstorm Watch 478. Additionally, 2-percent tornado probabilities were added along this corridor and westward into southeast/south-central KS and far northeast/north-central OK. Here, antecedent outflow is diurnally destabilizing amid rich boundary-layer moisture. Clockwise-curved low-level hodographs will support a localized tornado risk with any cells that can develop in this corridor. Farther west, significant-wind probabilities were added over northwest KS, southwest NE, and far eastern CO. Any thunderstorm clusters that evolve out of CO and move through this area will have the potential of producing gusts upward of 75 mph -- aided by steep deep-layer lapse rates and sufficiently elongated hodographs. Additionally, visible satellite imagery shows a shallow boundary-layer cumulus field along a surface wind shift in this general area. As storms move into this area of enhanced moisture and steep lapse rates, a brief tornado will be possible. Reference Severe Thunderstorm Watch 477 and MCD 1508 for the severe risk in the Upper Midwest, and MCDs 1509 and 1510 for the High Plains severe risk. ..Weinman.. 06/29/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Jun 29 2025/ ...Eastern KS/Western MO... An overnight MCS is slowly weakening over central MO, with an associated outflow boundary extending from eastern KS into south-central MO. Strong heating will occur along and south of the boundary, where several 12z CAM solutions indicate development of afternoon thunderstorms. Given this scenario, have extended the SLGT risk farther south into this region. Locally damaging wind gusts would be the main concern. Refer to MCD #1506 for further short-term details. ...WY/CO/SD/NE... A low-amplitude shortwave trough is digging into WY. As forcing associated with this system overspreads the High Plains of WY, high-based convection is expected. Thunderstorms will intensify as they track into a moderately unstable air mass and weak but backed low-level flow. Severe storms capable of large hail and damaging winds may affect the Black Hills region and southward into the NE Panhandle. Storms will also develop southward into the foothills of CO this afternoon and spread eastward. Winds and temperatures aloft are less favorable for organized/severe storms that far south, but at least isolated instances of large hail and damaging winds are possible. ...IA/WI... Strong heating is occurring across much of WI today, where a moist air mass will lead to moderate CAPE values. Thunderstorms will develop by mid-afternoon along a remnant weak boundary across central WI/northeast IA and spread northeastward through the day. Vertical shear is not particularly strong, and overall convective organization is expected to be low. Nevertheless, steep low-level lapse rates and ample instability will promote strong downdrafts and some hail in the strongest cells. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jun 29 2025 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY...AND OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Isolated to scattered strong to severe thunderstorms are possible from the upper Great Lakes into the central High Plains. Wind is the primary risk, though hail is expected across portions of the High Plains. ...20Z Update... The Slight risk was expanded southeastward from parts of the central Plains into the Middle MS Valley, where a cluster of thunderstorms is intensifying as it impinges on a strongly unstable air mass. The primary concern with this activity is damaging wind gusts. For information on the severe risk here, reference Severe Thunderstorm Watch 478. Additionally, 2-percent tornado probabilities were added along this corridor and westward into southeast/south-central KS and far northeast/north-central OK. Here, antecedent outflow is diurnally destabilizing amid rich boundary-layer moisture. Clockwise-curved low-level hodographs will support a localized tornado risk with any cells that can develop in this corridor. Farther west, significant-wind probabilities were added over northwest KS, southwest NE, and far eastern CO. Any thunderstorm clusters that evolve out of CO and move through this area will have the potential of producing gusts upward of 75 mph -- aided by steep deep-layer lapse rates and sufficiently elongated hodographs. Additionally, visible satellite imagery shows a shallow boundary-layer cumulus field along a surface wind shift in this general area. As storms move into this area of enhanced moisture and steep lapse rates, a brief tornado will be possible. Reference Severe Thunderstorm Watch 477 and MCD 1508 for the severe risk in the Upper Midwest, and MCDs 1509 and 1510 for the High Plains severe risk. ..Weinman.. 06/29/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Jun 29 2025/ ...Eastern KS/Western MO... An overnight MCS is slowly weakening over central MO, with an associated outflow boundary extending from eastern KS into south-central MO. Strong heating will occur along and south of the boundary, where several 12z CAM solutions indicate development of afternoon thunderstorms. Given this scenario, have extended the SLGT risk farther south into this region. Locally damaging wind gusts would be the main concern. Refer to MCD #1506 for further short-term details. ...WY/CO/SD/NE... A low-amplitude shortwave trough is digging into WY. As forcing associated with this system overspreads the High Plains of WY, high-based convection is expected. Thunderstorms will intensify as they track into a moderately unstable air mass and weak but backed low-level flow. Severe storms capable of large hail and damaging winds may affect the Black Hills region and southward into the NE Panhandle. Storms will also develop southward into the foothills of CO this afternoon and spread eastward. Winds and temperatures aloft are less favorable for organized/severe storms that far south, but at least isolated instances of large hail and damaging winds are possible. ...IA/WI... Strong heating is occurring across much of WI today, where a moist air mass will lead to moderate CAPE values. Thunderstorms will develop by mid-afternoon along a remnant weak boundary across central WI/northeast IA and spread northeastward through the day. Vertical shear is not particularly strong, and overall convective organization is expected to be low. Nevertheless, steep low-level lapse rates and ample instability will promote strong downdrafts and some hail in the strongest cells. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jun 29 2025 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY...AND OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Isolated to scattered strong to severe thunderstorms are possible from the upper Great Lakes into the central High Plains. Wind is the primary risk, though hail is expected across portions of the High Plains. ...20Z Update... The Slight risk was expanded southeastward from parts of the central Plains into the Middle MS Valley, where a cluster of thunderstorms is intensifying as it impinges on a strongly unstable air mass. The primary concern with this activity is damaging wind gusts. For information on the severe risk here, reference Severe Thunderstorm Watch 478. Additionally, 2-percent tornado probabilities were added along this corridor and westward into southeast/south-central KS and far northeast/north-central OK. Here, antecedent outflow is diurnally destabilizing amid rich boundary-layer moisture. Clockwise-curved low-level hodographs will support a localized tornado risk with any cells that can develop in this corridor. Farther west, significant-wind probabilities were added over northwest KS, southwest NE, and far eastern CO. Any thunderstorm clusters that evolve out of CO and move through this area will have the potential of producing gusts upward of 75 mph -- aided by steep deep-layer lapse rates and sufficiently elongated hodographs. Additionally, visible satellite imagery shows a shallow boundary-layer cumulus field along a surface wind shift in this general area. As storms move into this area of enhanced moisture and steep lapse rates, a brief tornado will be possible. Reference Severe Thunderstorm Watch 477 and MCD 1508 for the severe risk in the Upper Midwest, and MCDs 1509 and 1510 for the High Plains severe risk. ..Weinman.. 06/29/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Jun 29 2025/ ...Eastern KS/Western MO... An overnight MCS is slowly weakening over central MO, with an associated outflow boundary extending from eastern KS into south-central MO. Strong heating will occur along and south of the boundary, where several 12z CAM solutions indicate development of afternoon thunderstorms. Given this scenario, have extended the SLGT risk farther south into this region. Locally damaging wind gusts would be the main concern. Refer to MCD #1506 for further short-term details. ...WY/CO/SD/NE... A low-amplitude shortwave trough is digging into WY. As forcing associated with this system overspreads the High Plains of WY, high-based convection is expected. Thunderstorms will intensify as they track into a moderately unstable air mass and weak but backed low-level flow. Severe storms capable of large hail and damaging winds may affect the Black Hills region and southward into the NE Panhandle. Storms will also develop southward into the foothills of CO this afternoon and spread eastward. Winds and temperatures aloft are less favorable for organized/severe storms that far south, but at least isolated instances of large hail and damaging winds are possible. ...IA/WI... Strong heating is occurring across much of WI today, where a moist air mass will lead to moderate CAPE values. Thunderstorms will develop by mid-afternoon along a remnant weak boundary across central WI/northeast IA and spread northeastward through the day. Vertical shear is not particularly strong, and overall convective organization is expected to be low. Nevertheless, steep low-level lapse rates and ample instability will promote strong downdrafts and some hail in the strongest cells. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jun 29 2025 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY...AND OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Isolated to scattered strong to severe thunderstorms are possible from the upper Great Lakes into the central High Plains. Wind is the primary risk, though hail is expected across portions of the High Plains. ...20Z Update... The Slight risk was expanded southeastward from parts of the central Plains into the Middle MS Valley, where a cluster of thunderstorms is intensifying as it impinges on a strongly unstable air mass. The primary concern with this activity is damaging wind gusts. For information on the severe risk here, reference Severe Thunderstorm Watch 478. Additionally, 2-percent tornado probabilities were added along this corridor and westward into southeast/south-central KS and far northeast/north-central OK. Here, antecedent outflow is diurnally destabilizing amid rich boundary-layer moisture. Clockwise-curved low-level hodographs will support a localized tornado risk with any cells that can develop in this corridor. Farther west, significant-wind probabilities were added over northwest KS, southwest NE, and far eastern CO. Any thunderstorm clusters that evolve out of CO and move through this area will have the potential of producing gusts upward of 75 mph -- aided by steep deep-layer lapse rates and sufficiently elongated hodographs. Additionally, visible satellite imagery shows a shallow boundary-layer cumulus field along a surface wind shift in this general area. As storms move into this area of enhanced moisture and steep lapse rates, a brief tornado will be possible. Reference Severe Thunderstorm Watch 477 and MCD 1508 for the severe risk in the Upper Midwest, and MCDs 1509 and 1510 for the High Plains severe risk. ..Weinman.. 06/29/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Jun 29 2025/ ...Eastern KS/Western MO... An overnight MCS is slowly weakening over central MO, with an associated outflow boundary extending from eastern KS into south-central MO. Strong heating will occur along and south of the boundary, where several 12z CAM solutions indicate development of afternoon thunderstorms. Given this scenario, have extended the SLGT risk farther south into this region. Locally damaging wind gusts would be the main concern. Refer to MCD #1506 for further short-term details. ...WY/CO/SD/NE... A low-amplitude shortwave trough is digging into WY. As forcing associated with this system overspreads the High Plains of WY, high-based convection is expected. Thunderstorms will intensify as they track into a moderately unstable air mass and weak but backed low-level flow. Severe storms capable of large hail and damaging winds may affect the Black Hills region and southward into the NE Panhandle. Storms will also develop southward into the foothills of CO this afternoon and spread eastward. Winds and temperatures aloft are less favorable for organized/severe storms that far south, but at least isolated instances of large hail and damaging winds are possible. ...IA/WI... Strong heating is occurring across much of WI today, where a moist air mass will lead to moderate CAPE values. Thunderstorms will develop by mid-afternoon along a remnant weak boundary across central WI/northeast IA and spread northeastward through the day. Vertical shear is not particularly strong, and overall convective organization is expected to be low. Nevertheless, steep low-level lapse rates and ample instability will promote strong downdrafts and some hail in the strongest cells. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jun 29 2025 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY...AND OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Isolated to scattered strong to severe thunderstorms are possible from the upper Great Lakes into the central High Plains. Wind is the primary risk, though hail is expected across portions of the High Plains. ...20Z Update... The Slight risk was expanded southeastward from parts of the central Plains into the Middle MS Valley, where a cluster of thunderstorms is intensifying as it impinges on a strongly unstable air mass. The primary concern with this activity is damaging wind gusts. For information on the severe risk here, reference Severe Thunderstorm Watch 478. Additionally, 2-percent tornado probabilities were added along this corridor and westward into southeast/south-central KS and far northeast/north-central OK. Here, antecedent outflow is diurnally destabilizing amid rich boundary-layer moisture. Clockwise-curved low-level hodographs will support a localized tornado risk with any cells that can develop in this corridor. Farther west, significant-wind probabilities were added over northwest KS, southwest NE, and far eastern CO. Any thunderstorm clusters that evolve out of CO and move through this area will have the potential of producing gusts upward of 75 mph -- aided by steep deep-layer lapse rates and sufficiently elongated hodographs. Additionally, visible satellite imagery shows a shallow boundary-layer cumulus field along a surface wind shift in this general area. As storms move into this area of enhanced moisture and steep lapse rates, a brief tornado will be possible. Reference Severe Thunderstorm Watch 477 and MCD 1508 for the severe risk in the Upper Midwest, and MCDs 1509 and 1510 for the High Plains severe risk. ..Weinman.. 06/29/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Jun 29 2025/ ...Eastern KS/Western MO... An overnight MCS is slowly weakening over central MO, with an associated outflow boundary extending from eastern KS into south-central MO. Strong heating will occur along and south of the boundary, where several 12z CAM solutions indicate development of afternoon thunderstorms. Given this scenario, have extended the SLGT risk farther south into this region. Locally damaging wind gusts would be the main concern. Refer to MCD #1506 for further short-term details. ...WY/CO/SD/NE... A low-amplitude shortwave trough is digging into WY. As forcing associated with this system overspreads the High Plains of WY, high-based convection is expected. Thunderstorms will intensify as they track into a moderately unstable air mass and weak but backed low-level flow. Severe storms capable of large hail and damaging winds may affect the Black Hills region and southward into the NE Panhandle. Storms will also develop southward into the foothills of CO this afternoon and spread eastward. Winds and temperatures aloft are less favorable for organized/severe storms that far south, but at least isolated instances of large hail and damaging winds are possible. ...IA/WI... Strong heating is occurring across much of WI today, where a moist air mass will lead to moderate CAPE values. Thunderstorms will develop by mid-afternoon along a remnant weak boundary across central WI/northeast IA and spread northeastward through the day. Vertical shear is not particularly strong, and overall convective organization is expected to be low. Nevertheless, steep low-level lapse rates and ample instability will promote strong downdrafts and some hail in the strongest cells. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0300 PM CDT Sun Jun 29 2025 Valid 292000Z - 301200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL PLAINS INTO THE MIDDLE MISSISSIPPI VALLEY...AND OVER PARTS OF THE UPPER MIDWEST... ...SUMMARY... Isolated to scattered strong to severe thunderstorms are possible from the upper Great Lakes into the central High Plains. Wind is the primary risk, though hail is expected across portions of the High Plains. ...20Z Update... The Slight risk was expanded southeastward from parts of the central Plains into the Middle MS Valley, where a cluster of thunderstorms is intensifying as it impinges on a strongly unstable air mass. The primary concern with this activity is damaging wind gusts. For information on the severe risk here, reference Severe Thunderstorm Watch 478. Additionally, 2-percent tornado probabilities were added along this corridor and westward into southeast/south-central KS and far northeast/north-central OK. Here, antecedent outflow is diurnally destabilizing amid rich boundary-layer moisture. Clockwise-curved low-level hodographs will support a localized tornado risk with any cells that can develop in this corridor. Farther west, significant-wind probabilities were added over northwest KS, southwest NE, and far eastern CO. Any thunderstorm clusters that evolve out of CO and move through this area will have the potential of producing gusts upward of 75 mph -- aided by steep deep-layer lapse rates and sufficiently elongated hodographs. Additionally, visible satellite imagery shows a shallow boundary-layer cumulus field along a surface wind shift in this general area. As storms move into this area of enhanced moisture and steep lapse rates, a brief tornado will be possible. Reference Severe Thunderstorm Watch 477 and MCD 1508 for the severe risk in the Upper Midwest, and MCDs 1509 and 1510 for the High Plains severe risk. ..Weinman.. 06/29/2025 .PREV DISCUSSION... /ISSUED 1130 AM CDT Sun Jun 29 2025/ ...Eastern KS/Western MO... An overnight MCS is slowly weakening over central MO, with an associated outflow boundary extending from eastern KS into south-central MO. Strong heating will occur along and south of the boundary, where several 12z CAM solutions indicate development of afternoon thunderstorms. Given this scenario, have extended the SLGT risk farther south into this region. Locally damaging wind gusts would be the main concern. Refer to MCD #1506 for further short-term details. ...WY/CO/SD/NE... A low-amplitude shortwave trough is digging into WY. As forcing associated with this system overspreads the High Plains of WY, high-based convection is expected. Thunderstorms will intensify as they track into a moderately unstable air mass and weak but backed low-level flow. Severe storms capable of large hail and damaging winds may affect the Black Hills region and southward into the NE Panhandle. Storms will also develop southward into the foothills of CO this afternoon and spread eastward. Winds and temperatures aloft are less favorable for organized/severe storms that far south, but at least isolated instances of large hail and damaging winds are possible. ...IA/WI... Strong heating is occurring across much of WI today, where a moist air mass will lead to moderate CAPE values. Thunderstorms will develop by mid-afternoon along a remnant weak boundary across central WI/northeast IA and spread northeastward through the day. Vertical shear is not particularly strong, and overall convective organization is expected to be low. Nevertheless, steep low-level lapse rates and ample instability will promote strong downdrafts and some hail in the strongest cells. Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Sun Jun 29 2025 Valid 301200Z - 011200Z ...Northwest... Northern extent of isolated dry thunderstorm threat was trimmed owing to expected decrease in thunderstorm intensity/lightning production late Monday, closer to the Columbia Gorge. Otherwise, forecast (see below) remains on track. ...Great Basin... Advancing mid-level trough into the Western U.S. with attendant increasing mid-level winds atop a very dry/well-mixed boundary later will support Elevated fire weather conditions across portions of central and eastern Nevada Monday. Sustained south winds of around 15 mph combined with afternoon relative humidity of 10-15 percent along with dry fuels will increase wildfire spread potential. ...Southwest and Upper-Colorado River Basin... Shower and thunderstorm development is expected along higher terrain Monday afternoon as monsoon moisture advances into the Great Four Corners Region. A few dry thunderstorms are expected across southwest Colorado, western New Mexico and into the White Mountains of southeast Arizona. Slow thunderstorm motions in proximity to a Four Corners high, a marked increase in monsoon moisture magnitude and relative humidity into the region through midweek along with improving fuel indices should limit potential spread of ignitions. ..Williams.. 06/29/2025 .PREV DISCUSSION... /ISSUED 0204 AM CDT Sun Jun 29 2025/ ...Synopsis... As mid-level ridging builds over the western US, a weak subtropical low will deepen along the western periphery of the ridge across CA Monday. The building mid-level heights and approach of the upper trough will allow robust mid-level moisture to shift northward across portions of the West. ...Northwest... Heating across the higher terrain, coupled with weak ascent from the approaching upper trough will allow for isolated to widely scattered thunderstorms across northern CA and southern OR Monday afternoon and evening. Dry sub-cloud layers with steep lapse rates below 500mb will support a mixed wet/dry thunderstorm environment. Given the potential for dry lightning atop receptive fuels, an IsoDryT area has been added across parts of the Northwest where fire starts are possible. ...Great Basin... Farther south, beneath the upper ridge, very hot surface temperatures are expected over parts of NV and western UT. While surface winds are not expected to be overly strong, widespread RH values below 15% will be present. Occasional 15 mph wind gusts on a local basis and the hot/dry conditions could support a few hours of locally elevated fire-weather potential over dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Sun Jun 29 2025 Valid 301200Z - 011200Z ...Northwest... Northern extent of isolated dry thunderstorm threat was trimmed owing to expected decrease in thunderstorm intensity/lightning production late Monday, closer to the Columbia Gorge. Otherwise, forecast (see below) remains on track. ...Great Basin... Advancing mid-level trough into the Western U.S. with attendant increasing mid-level winds atop a very dry/well-mixed boundary later will support Elevated fire weather conditions across portions of central and eastern Nevada Monday. Sustained south winds of around 15 mph combined with afternoon relative humidity of 10-15 percent along with dry fuels will increase wildfire spread potential. ...Southwest and Upper-Colorado River Basin... Shower and thunderstorm development is expected along higher terrain Monday afternoon as monsoon moisture advances into the Great Four Corners Region. A few dry thunderstorms are expected across southwest Colorado, western New Mexico and into the White Mountains of southeast Arizona. Slow thunderstorm motions in proximity to a Four Corners high, a marked increase in monsoon moisture magnitude and relative humidity into the region through midweek along with improving fuel indices should limit potential spread of ignitions. ..Williams.. 06/29/2025 .PREV DISCUSSION... /ISSUED 0204 AM CDT Sun Jun 29 2025/ ...Synopsis... As mid-level ridging builds over the western US, a weak subtropical low will deepen along the western periphery of the ridge across CA Monday. The building mid-level heights and approach of the upper trough will allow robust mid-level moisture to shift northward across portions of the West. ...Northwest... Heating across the higher terrain, coupled with weak ascent from the approaching upper trough will allow for isolated to widely scattered thunderstorms across northern CA and southern OR Monday afternoon and evening. Dry sub-cloud layers with steep lapse rates below 500mb will support a mixed wet/dry thunderstorm environment. Given the potential for dry lightning atop receptive fuels, an IsoDryT area has been added across parts of the Northwest where fire starts are possible. ...Great Basin... Farther south, beneath the upper ridge, very hot surface temperatures are expected over parts of NV and western UT. While surface winds are not expected to be overly strong, widespread RH values below 15% will be present. Occasional 15 mph wind gusts on a local basis and the hot/dry conditions could support a few hours of locally elevated fire-weather potential over dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Sun Jun 29 2025 Valid 301200Z - 011200Z ...Northwest... Northern extent of isolated dry thunderstorm threat was trimmed owing to expected decrease in thunderstorm intensity/lightning production late Monday, closer to the Columbia Gorge. Otherwise, forecast (see below) remains on track. ...Great Basin... Advancing mid-level trough into the Western U.S. with attendant increasing mid-level winds atop a very dry/well-mixed boundary later will support Elevated fire weather conditions across portions of central and eastern Nevada Monday. Sustained south winds of around 15 mph combined with afternoon relative humidity of 10-15 percent along with dry fuels will increase wildfire spread potential. ...Southwest and Upper-Colorado River Basin... Shower and thunderstorm development is expected along higher terrain Monday afternoon as monsoon moisture advances into the Great Four Corners Region. A few dry thunderstorms are expected across southwest Colorado, western New Mexico and into the White Mountains of southeast Arizona. Slow thunderstorm motions in proximity to a Four Corners high, a marked increase in monsoon moisture magnitude and relative humidity into the region through midweek along with improving fuel indices should limit potential spread of ignitions. ..Williams.. 06/29/2025 .PREV DISCUSSION... /ISSUED 0204 AM CDT Sun Jun 29 2025/ ...Synopsis... As mid-level ridging builds over the western US, a weak subtropical low will deepen along the western periphery of the ridge across CA Monday. The building mid-level heights and approach of the upper trough will allow robust mid-level moisture to shift northward across portions of the West. ...Northwest... Heating across the higher terrain, coupled with weak ascent from the approaching upper trough will allow for isolated to widely scattered thunderstorms across northern CA and southern OR Monday afternoon and evening. Dry sub-cloud layers with steep lapse rates below 500mb will support a mixed wet/dry thunderstorm environment. Given the potential for dry lightning atop receptive fuels, an IsoDryT area has been added across parts of the Northwest where fire starts are possible. ...Great Basin... Farther south, beneath the upper ridge, very hot surface temperatures are expected over parts of NV and western UT. While surface winds are not expected to be overly strong, widespread RH values below 15% will be present. Occasional 15 mph wind gusts on a local basis and the hot/dry conditions could support a few hours of locally elevated fire-weather potential over dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0255 PM CDT Sun Jun 29 2025 Valid 301200Z - 011200Z ...Northwest... Northern extent of isolated dry thunderstorm threat was trimmed owing to expected decrease in thunderstorm intensity/lightning production late Monday, closer to the Columbia Gorge. Otherwise, forecast (see below) remains on track. ...Great Basin... Advancing mid-level trough into the Western U.S. with attendant increasing mid-level winds atop a very dry/well-mixed boundary later will support Elevated fire weather conditions across portions of central and eastern Nevada Monday. Sustained south winds of around 15 mph combined with afternoon relative humidity of 10-15 percent along with dry fuels will increase wildfire spread potential. ...Southwest and Upper-Colorado River Basin... Shower and thunderstorm development is expected along higher terrain Monday afternoon as monsoon moisture advances into the Great Four Corners Region. A few dry thunderstorms are expected across southwest Colorado, western New Mexico and into the White Mountains of southeast Arizona. Slow thunderstorm motions in proximity to a Four Corners high, a marked increase in monsoon moisture magnitude and relative humidity into the region through midweek along with improving fuel indices should limit potential spread of ignitions. ..Williams.. 06/29/2025 .PREV DISCUSSION... /ISSUED 0204 AM CDT Sun Jun 29 2025/ ...Synopsis... As mid-level ridging builds over the western US, a weak subtropical low will deepen along the western periphery of the ridge across CA Monday. The building mid-level heights and approach of the upper trough will allow robust mid-level moisture to shift northward across portions of the West. ...Northwest... Heating across the higher terrain, coupled with weak ascent from the approaching upper trough will allow for isolated to widely scattered thunderstorms across northern CA and southern OR Monday afternoon and evening. Dry sub-cloud layers with steep lapse rates below 500mb will support a mixed wet/dry thunderstorm environment. Given the potential for dry lightning atop receptive fuels, an IsoDryT area has been added across parts of the Northwest where fire starts are possible. ...Great Basin... Farther south, beneath the upper ridge, very hot surface temperatures are expected over parts of NV and western UT. While surface winds are not expected to be overly strong, widespread RH values below 15% will be present. Occasional 15 mph wind gusts on a local basis and the hot/dry conditions could support a few hours of locally elevated fire-weather potential over dry fuels. ...Please see www.spc.noaa.gov/fire for graphic product... Read more