Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0119 AM CDT Tue Jul 01 2025 Valid 011200Z - 021200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN AND CENTRAL NEVADA... ...Synopsis... An amplified upper trough slowly progressing eastward across central California will be responsible for supporting mixed dry/wet thunderstorms across portions of northern California into southern Oregon, critical fire-weather conditions across portions of southern and central Nevada, and for pushing enough monsoonal moisture into portions of Arizona, Utah, and southeastern Idaho to support lightning over dry fuels. ...Central/Southern Nevada... Deep boundary layer mixing below strong meridional mid-level flow will result in dry and windy conditions that overlap with fuels receptive to wildfire spread (ERCs at or exceeding the 90th annual percentile). Relative humidity of 5-10% coupled with 25 MPH winds, possibly gusting to 30 MPH, are anticipated across portions of central and southern Nevada -- warranting the introduction of Critical highlights. ...Dry Thunderstorms... A mix of wet/dry thunderstorms are anticipated across portions of northern California into southern and eastern Oregon. Thunderstorms are expected to develop within deep inverted-v boundary-layer profiles with total precipitable water content between 0.5 - 0.75 in, and 0 - 6 km mean wind speeds of 15-20 MPH. With ERC percentiles climbing to the 70th-80th annual percentiles, lightning over dry fuels with little wetting precipitation will pose a fire-weather risk. Further east across portions of northern Arizona, western/central Utah, and far southeastern Idaho, a mix of wet and dry thunderstorms is expected. ERC fuel percentiles are more significant across this region, ranging from the 90th annual percentiles to exceeding the 98th annual percentiles across large portions of the region. With total precipitable water vapor content forecast between 0.5 and 0.8 inches resulting in lower precipitation efficiency, dry lightning ignitions will be possible. ..Halbert.. 07/01/2025 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Tue Jul 01 2025 Valid 021200Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EASTERN OREGON TO NORTHERN MONTANA AND FAR NORTHWEST NORTH DAKOTA AND FROM THE UPPER MIDWEST TO THE CENTRAL GREAT LAKES.... ...SUMMARY... At least scattered storms are possible across a large portion of the continental U.S. on Wednesday. A couple of severe gusts may accompany the stronger storms over portions of the Northern Rockies and the Upper Midwest to central Michigan region. ...Synopsis... A ridge centered across the northern Plains will drift slowly east through the period. To the east of this ridge, a mid-level trough and associated jet streak will dig into the Great Lakes. To the west of this ridge, several embedded shortwave troughs are forecast within moderate southwesterly flow. ...Eastern Oregon to northern Montana and far northwest North Dakota... Scattered thunderstorms are forecast within a zone of steep low/mid-level lapse rates from eastern Oregon into much of Montana. Effective shear of 25 to 30 knots will support some storm maintenance/organization including the potential for multicell clusters. A hot and well-mixed boundary layer featuring 40-50F dewpoint depressions will support some threat for isolated severe wind gusts from this activity. However, weak instability should limit a greater severe weather threat. ...Upper Midwest across Lake Michigan and much of central/northern Lower Michigan... Elevated thunderstorms may be ongoing at the beginning of the period across eastern South Dakota/western Iowa on the nose of the low-level jet. This activity should weaken during the morning. Weak to moderate instability is forecast do develop during the afternoon from the Upper Midwest to northern/central Lower Michigan. A weak mid-level shortwave trough is forecast to move southeastward across this region Wednesday afternoon. As this occurs, isolated to potentially scattered thunderstorms are possible. 35 to 40 knots of mid-level flow may support some storm organization, including the potential for transient supercells. Isolated large hail and damaging wind gusts will be the primary threat. ..Bentley.. 07/01/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Tue Jul 01 2025 Valid 021200Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EASTERN OREGON TO NORTHERN MONTANA AND FAR NORTHWEST NORTH DAKOTA AND FROM THE UPPER MIDWEST TO THE CENTRAL GREAT LAKES.... ...SUMMARY... At least scattered storms are possible across a large portion of the continental U.S. on Wednesday. A couple of severe gusts may accompany the stronger storms over portions of the Northern Rockies and the Upper Midwest to central Michigan region. ...Synopsis... A ridge centered across the northern Plains will drift slowly east through the period. To the east of this ridge, a mid-level trough and associated jet streak will dig into the Great Lakes. To the west of this ridge, several embedded shortwave troughs are forecast within moderate southwesterly flow. ...Eastern Oregon to northern Montana and far northwest North Dakota... Scattered thunderstorms are forecast within a zone of steep low/mid-level lapse rates from eastern Oregon into much of Montana. Effective shear of 25 to 30 knots will support some storm maintenance/organization including the potential for multicell clusters. A hot and well-mixed boundary layer featuring 40-50F dewpoint depressions will support some threat for isolated severe wind gusts from this activity. However, weak instability should limit a greater severe weather threat. ...Upper Midwest across Lake Michigan and much of central/northern Lower Michigan... Elevated thunderstorms may be ongoing at the beginning of the period across eastern South Dakota/western Iowa on the nose of the low-level jet. This activity should weaken during the morning. Weak to moderate instability is forecast do develop during the afternoon from the Upper Midwest to northern/central Lower Michigan. A weak mid-level shortwave trough is forecast to move southeastward across this region Wednesday afternoon. As this occurs, isolated to potentially scattered thunderstorms are possible. 35 to 40 knots of mid-level flow may support some storm organization, including the potential for transient supercells. Isolated large hail and damaging wind gusts will be the primary threat. ..Bentley.. 07/01/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Tue Jul 01 2025 Valid 021200Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EASTERN OREGON TO NORTHERN MONTANA AND FAR NORTHWEST NORTH DAKOTA AND FROM THE UPPER MIDWEST TO THE CENTRAL GREAT LAKES.... ...SUMMARY... At least scattered storms are possible across a large portion of the continental U.S. on Wednesday. A couple of severe gusts may accompany the stronger storms over portions of the Northern Rockies and the Upper Midwest to central Michigan region. ...Synopsis... A ridge centered across the northern Plains will drift slowly east through the period. To the east of this ridge, a mid-level trough and associated jet streak will dig into the Great Lakes. To the west of this ridge, several embedded shortwave troughs are forecast within moderate southwesterly flow. ...Eastern Oregon to northern Montana and far northwest North Dakota... Scattered thunderstorms are forecast within a zone of steep low/mid-level lapse rates from eastern Oregon into much of Montana. Effective shear of 25 to 30 knots will support some storm maintenance/organization including the potential for multicell clusters. A hot and well-mixed boundary layer featuring 40-50F dewpoint depressions will support some threat for isolated severe wind gusts from this activity. However, weak instability should limit a greater severe weather threat. ...Upper Midwest across Lake Michigan and much of central/northern Lower Michigan... Elevated thunderstorms may be ongoing at the beginning of the period across eastern South Dakota/western Iowa on the nose of the low-level jet. This activity should weaken during the morning. Weak to moderate instability is forecast do develop during the afternoon from the Upper Midwest to northern/central Lower Michigan. A weak mid-level shortwave trough is forecast to move southeastward across this region Wednesday afternoon. As this occurs, isolated to potentially scattered thunderstorms are possible. 35 to 40 knots of mid-level flow may support some storm organization, including the potential for transient supercells. Isolated large hail and damaging wind gusts will be the primary threat. ..Bentley.. 07/01/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Tue Jul 01 2025 Valid 021200Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EASTERN OREGON TO NORTHERN MONTANA AND FAR NORTHWEST NORTH DAKOTA AND FROM THE UPPER MIDWEST TO THE CENTRAL GREAT LAKES.... ...SUMMARY... At least scattered storms are possible across a large portion of the continental U.S. on Wednesday. A couple of severe gusts may accompany the stronger storms over portions of the Northern Rockies and the Upper Midwest to central Michigan region. ...Synopsis... A ridge centered across the northern Plains will drift slowly east through the period. To the east of this ridge, a mid-level trough and associated jet streak will dig into the Great Lakes. To the west of this ridge, several embedded shortwave troughs are forecast within moderate southwesterly flow. ...Eastern Oregon to northern Montana and far northwest North Dakota... Scattered thunderstorms are forecast within a zone of steep low/mid-level lapse rates from eastern Oregon into much of Montana. Effective shear of 25 to 30 knots will support some storm maintenance/organization including the potential for multicell clusters. A hot and well-mixed boundary layer featuring 40-50F dewpoint depressions will support some threat for isolated severe wind gusts from this activity. However, weak instability should limit a greater severe weather threat. ...Upper Midwest across Lake Michigan and much of central/northern Lower Michigan... Elevated thunderstorms may be ongoing at the beginning of the period across eastern South Dakota/western Iowa on the nose of the low-level jet. This activity should weaken during the morning. Weak to moderate instability is forecast do develop during the afternoon from the Upper Midwest to northern/central Lower Michigan. A weak mid-level shortwave trough is forecast to move southeastward across this region Wednesday afternoon. As this occurs, isolated to potentially scattered thunderstorms are possible. 35 to 40 knots of mid-level flow may support some storm organization, including the potential for transient supercells. Isolated large hail and damaging wind gusts will be the primary threat. ..Bentley.. 07/01/2025 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1256 AM CDT Tue Jul 01 2025 Valid 021200Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM EASTERN OREGON TO NORTHERN MONTANA AND FAR NORTHWEST NORTH DAKOTA AND FROM THE UPPER MIDWEST TO THE CENTRAL GREAT LAKES.... ...SUMMARY... At least scattered storms are possible across a large portion of the continental U.S. on Wednesday. A couple of severe gusts may accompany the stronger storms over portions of the Northern Rockies and the Upper Midwest to central Michigan region. ...Synopsis... A ridge centered across the northern Plains will drift slowly east through the period. To the east of this ridge, a mid-level trough and associated jet streak will dig into the Great Lakes. To the west of this ridge, several embedded shortwave troughs are forecast within moderate southwesterly flow. ...Eastern Oregon to northern Montana and far northwest North Dakota... Scattered thunderstorms are forecast within a zone of steep low/mid-level lapse rates from eastern Oregon into much of Montana. Effective shear of 25 to 30 knots will support some storm maintenance/organization including the potential for multicell clusters. A hot and well-mixed boundary layer featuring 40-50F dewpoint depressions will support some threat for isolated severe wind gusts from this activity. However, weak instability should limit a greater severe weather threat. ...Upper Midwest across Lake Michigan and much of central/northern Lower Michigan... Elevated thunderstorms may be ongoing at the beginning of the period across eastern South Dakota/western Iowa on the nose of the low-level jet. This activity should weaken during the morning. Weak to moderate instability is forecast do develop during the afternoon from the Upper Midwest to northern/central Lower Michigan. A weak mid-level shortwave trough is forecast to move southeastward across this region Wednesday afternoon. As this occurs, isolated to potentially scattered thunderstorms are possible. 35 to 40 knots of mid-level flow may support some storm organization, including the potential for transient supercells. Isolated large hail and damaging wind gusts will be the primary threat. ..Bentley.. 07/01/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Tue Jul 01 2025 Valid 011200Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE ATLANTIC REGION... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. An isolated severe storm may also occur over parts of the High Plains. ...Middle Atlantic... Upper trough currently located over the upper Great Lakes, extending into central MO, is forecast to shift into the OH Valley by late afternoon before advancing across the northern/central Appalachians by the end of the period. At the surface, a cold front will progress into the upper OH Valley early in the period and this will serve as the focus for scattered thunderstorms by mid day. Early this morning, water-vapor imagery suggests a weak low-amplitude short-wave trough is embedded within the base of the larger trough along the IL/IN border. Radar data supports this with a few clusters of thunderstorms extending from western IN into western TN. Current speed/movement of this feature would place this short wave into southern OH/eastern KY by 18z. While low-level lapse rates are not forecast to be that steep across the Middle Atlantic, modest southwesterly mid-level flow will contribute to adequate shear, supporting organized line segments/clusters. Current thinking is scattered thunderstorms will readily develop ahead of this feature, and a marked increase in convection should be noted into the mid afternoon across southern PA into northern VA. Latest HREF guidance supports this scenario, and forecast soundings favor damaging winds with convection that develops within a high-PW air mass, despite marginal lapse rates/instability. Strong-severe convection should spread off the Middle Atlantic Coast during the evening. ...High Plains... A weak short-wave trough appears to be topping the Rockies ridge over eastern ID/southern MT early this morning. This feature will begin to dig southeast toward the Black Hills, eventually migrating into the lower MO Valley by the end of the period. As a result, a weak lee trough should extend across eastern WY during the late afternoon and isolated thunderstorms are expected to develop across the High Plains of western SD into the NE Panhandle/northeast CO. Some consideration was given to a SLGT Risk across this region but activity may prove too sparse to warrant higher severe probabilities. Even so, wind profiles suggest a few slow-moving supercells could develop. With LLJ expected to strengthen across this region after sunset, this would favor a few longer-lived storms. If it appears coverage will be a bit more expansive then currently forecast, a SLGT Risk may be warranted. ..Darrow/Halbert.. 07/01/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Tue Jul 01 2025 Valid 011200Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE ATLANTIC REGION... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. An isolated severe storm may also occur over parts of the High Plains. ...Middle Atlantic... Upper trough currently located over the upper Great Lakes, extending into central MO, is forecast to shift into the OH Valley by late afternoon before advancing across the northern/central Appalachians by the end of the period. At the surface, a cold front will progress into the upper OH Valley early in the period and this will serve as the focus for scattered thunderstorms by mid day. Early this morning, water-vapor imagery suggests a weak low-amplitude short-wave trough is embedded within the base of the larger trough along the IL/IN border. Radar data supports this with a few clusters of thunderstorms extending from western IN into western TN. Current speed/movement of this feature would place this short wave into southern OH/eastern KY by 18z. While low-level lapse rates are not forecast to be that steep across the Middle Atlantic, modest southwesterly mid-level flow will contribute to adequate shear, supporting organized line segments/clusters. Current thinking is scattered thunderstorms will readily develop ahead of this feature, and a marked increase in convection should be noted into the mid afternoon across southern PA into northern VA. Latest HREF guidance supports this scenario, and forecast soundings favor damaging winds with convection that develops within a high-PW air mass, despite marginal lapse rates/instability. Strong-severe convection should spread off the Middle Atlantic Coast during the evening. ...High Plains... A weak short-wave trough appears to be topping the Rockies ridge over eastern ID/southern MT early this morning. This feature will begin to dig southeast toward the Black Hills, eventually migrating into the lower MO Valley by the end of the period. As a result, a weak lee trough should extend across eastern WY during the late afternoon and isolated thunderstorms are expected to develop across the High Plains of western SD into the NE Panhandle/northeast CO. Some consideration was given to a SLGT Risk across this region but activity may prove too sparse to warrant higher severe probabilities. Even so, wind profiles suggest a few slow-moving supercells could develop. With LLJ expected to strengthen across this region after sunset, this would favor a few longer-lived storms. If it appears coverage will be a bit more expansive then currently forecast, a SLGT Risk may be warranted. ..Darrow/Halbert.. 07/01/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Tue Jul 01 2025 Valid 011200Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE ATLANTIC REGION... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. An isolated severe storm may also occur over parts of the High Plains. ...Middle Atlantic... Upper trough currently located over the upper Great Lakes, extending into central MO, is forecast to shift into the OH Valley by late afternoon before advancing across the northern/central Appalachians by the end of the period. At the surface, a cold front will progress into the upper OH Valley early in the period and this will serve as the focus for scattered thunderstorms by mid day. Early this morning, water-vapor imagery suggests a weak low-amplitude short-wave trough is embedded within the base of the larger trough along the IL/IN border. Radar data supports this with a few clusters of thunderstorms extending from western IN into western TN. Current speed/movement of this feature would place this short wave into southern OH/eastern KY by 18z. While low-level lapse rates are not forecast to be that steep across the Middle Atlantic, modest southwesterly mid-level flow will contribute to adequate shear, supporting organized line segments/clusters. Current thinking is scattered thunderstorms will readily develop ahead of this feature, and a marked increase in convection should be noted into the mid afternoon across southern PA into northern VA. Latest HREF guidance supports this scenario, and forecast soundings favor damaging winds with convection that develops within a high-PW air mass, despite marginal lapse rates/instability. Strong-severe convection should spread off the Middle Atlantic Coast during the evening. ...High Plains... A weak short-wave trough appears to be topping the Rockies ridge over eastern ID/southern MT early this morning. This feature will begin to dig southeast toward the Black Hills, eventually migrating into the lower MO Valley by the end of the period. As a result, a weak lee trough should extend across eastern WY during the late afternoon and isolated thunderstorms are expected to develop across the High Plains of western SD into the NE Panhandle/northeast CO. Some consideration was given to a SLGT Risk across this region but activity may prove too sparse to warrant higher severe probabilities. Even so, wind profiles suggest a few slow-moving supercells could develop. With LLJ expected to strengthen across this region after sunset, this would favor a few longer-lived storms. If it appears coverage will be a bit more expansive then currently forecast, a SLGT Risk may be warranted. ..Darrow/Halbert.. 07/01/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Tue Jul 01 2025 Valid 011200Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE ATLANTIC REGION... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. An isolated severe storm may also occur over parts of the High Plains. ...Middle Atlantic... Upper trough currently located over the upper Great Lakes, extending into central MO, is forecast to shift into the OH Valley by late afternoon before advancing across the northern/central Appalachians by the end of the period. At the surface, a cold front will progress into the upper OH Valley early in the period and this will serve as the focus for scattered thunderstorms by mid day. Early this morning, water-vapor imagery suggests a weak low-amplitude short-wave trough is embedded within the base of the larger trough along the IL/IN border. Radar data supports this with a few clusters of thunderstorms extending from western IN into western TN. Current speed/movement of this feature would place this short wave into southern OH/eastern KY by 18z. While low-level lapse rates are not forecast to be that steep across the Middle Atlantic, modest southwesterly mid-level flow will contribute to adequate shear, supporting organized line segments/clusters. Current thinking is scattered thunderstorms will readily develop ahead of this feature, and a marked increase in convection should be noted into the mid afternoon across southern PA into northern VA. Latest HREF guidance supports this scenario, and forecast soundings favor damaging winds with convection that develops within a high-PW air mass, despite marginal lapse rates/instability. Strong-severe convection should spread off the Middle Atlantic Coast during the evening. ...High Plains... A weak short-wave trough appears to be topping the Rockies ridge over eastern ID/southern MT early this morning. This feature will begin to dig southeast toward the Black Hills, eventually migrating into the lower MO Valley by the end of the period. As a result, a weak lee trough should extend across eastern WY during the late afternoon and isolated thunderstorms are expected to develop across the High Plains of western SD into the NE Panhandle/northeast CO. Some consideration was given to a SLGT Risk across this region but activity may prove too sparse to warrant higher severe probabilities. Even so, wind profiles suggest a few slow-moving supercells could develop. With LLJ expected to strengthen across this region after sunset, this would favor a few longer-lived storms. If it appears coverage will be a bit more expansive then currently forecast, a SLGT Risk may be warranted. ..Darrow/Halbert.. 07/01/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Tue Jul 01 2025 Valid 011200Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE ATLANTIC REGION... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. An isolated severe storm may also occur over parts of the High Plains. ...Middle Atlantic... Upper trough currently located over the upper Great Lakes, extending into central MO, is forecast to shift into the OH Valley by late afternoon before advancing across the northern/central Appalachians by the end of the period. At the surface, a cold front will progress into the upper OH Valley early in the period and this will serve as the focus for scattered thunderstorms by mid day. Early this morning, water-vapor imagery suggests a weak low-amplitude short-wave trough is embedded within the base of the larger trough along the IL/IN border. Radar data supports this with a few clusters of thunderstorms extending from western IN into western TN. Current speed/movement of this feature would place this short wave into southern OH/eastern KY by 18z. While low-level lapse rates are not forecast to be that steep across the Middle Atlantic, modest southwesterly mid-level flow will contribute to adequate shear, supporting organized line segments/clusters. Current thinking is scattered thunderstorms will readily develop ahead of this feature, and a marked increase in convection should be noted into the mid afternoon across southern PA into northern VA. Latest HREF guidance supports this scenario, and forecast soundings favor damaging winds with convection that develops within a high-PW air mass, despite marginal lapse rates/instability. Strong-severe convection should spread off the Middle Atlantic Coast during the evening. ...High Plains... A weak short-wave trough appears to be topping the Rockies ridge over eastern ID/southern MT early this morning. This feature will begin to dig southeast toward the Black Hills, eventually migrating into the lower MO Valley by the end of the period. As a result, a weak lee trough should extend across eastern WY during the late afternoon and isolated thunderstorms are expected to develop across the High Plains of western SD into the NE Panhandle/northeast CO. Some consideration was given to a SLGT Risk across this region but activity may prove too sparse to warrant higher severe probabilities. Even so, wind profiles suggest a few slow-moving supercells could develop. With LLJ expected to strengthen across this region after sunset, this would favor a few longer-lived storms. If it appears coverage will be a bit more expansive then currently forecast, a SLGT Risk may be warranted. ..Darrow/Halbert.. 07/01/2025 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1248 AM CDT Tue Jul 01 2025 Valid 011200Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MIDDLE ATLANTIC REGION... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. An isolated severe storm may also occur over parts of the High Plains. ...Middle Atlantic... Upper trough currently located over the upper Great Lakes, extending into central MO, is forecast to shift into the OH Valley by late afternoon before advancing across the northern/central Appalachians by the end of the period. At the surface, a cold front will progress into the upper OH Valley early in the period and this will serve as the focus for scattered thunderstorms by mid day. Early this morning, water-vapor imagery suggests a weak low-amplitude short-wave trough is embedded within the base of the larger trough along the IL/IN border. Radar data supports this with a few clusters of thunderstorms extending from western IN into western TN. Current speed/movement of this feature would place this short wave into southern OH/eastern KY by 18z. While low-level lapse rates are not forecast to be that steep across the Middle Atlantic, modest southwesterly mid-level flow will contribute to adequate shear, supporting organized line segments/clusters. Current thinking is scattered thunderstorms will readily develop ahead of this feature, and a marked increase in convection should be noted into the mid afternoon across southern PA into northern VA. Latest HREF guidance supports this scenario, and forecast soundings favor damaging winds with convection that develops within a high-PW air mass, despite marginal lapse rates/instability. Strong-severe convection should spread off the Middle Atlantic Coast during the evening. ...High Plains... A weak short-wave trough appears to be topping the Rockies ridge over eastern ID/southern MT early this morning. This feature will begin to dig southeast toward the Black Hills, eventually migrating into the lower MO Valley by the end of the period. As a result, a weak lee trough should extend across eastern WY during the late afternoon and isolated thunderstorms are expected to develop across the High Plains of western SD into the NE Panhandle/northeast CO. Some consideration was given to a SLGT Risk across this region but activity may prove too sparse to warrant higher severe probabilities. Even so, wind profiles suggest a few slow-moving supercells could develop. With LLJ expected to strengthen across this region after sunset, this would favor a few longer-lived storms. If it appears coverage will be a bit more expansive then currently forecast, a SLGT Risk may be warranted. ..Darrow/Halbert.. 07/01/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 PM CDT Mon Jun 30 2025 Valid 010100Z - 011200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDDLE ATLANTIC...RED RIVER REGION OF THE SOUTHERN PLAINS...SOUTHWESTERN BORDER AREA...AND PACIFIC NORTHWEST... ...SUMMARY... Isolated strong, to locally severe, thunderstorms will persist for a few hours this evening. Damaging gusts are the primary concern. ...01z Update... Diurnal heating, and steepening of the boundary layer, has been the primary instigator for scattered convection across much of the CONUS this afternoon. Many areas have been efficiently overturned and with onset of nocturnal cooling, further stabilization is expected this evening. Even so, for the next few hours a few pockets of robust convection will likely persist. Moderate to strong buoyancy is noted across the Delmarva and the Red River region of southern OK/north TX. Deep convection may continue to generate locally strong winds until this activity weakens by mid evening. Isolated wind gusts may also accompany high-based convection across southeast AZ/southern NM, and near the OR/CA border. Boundary-layer cooling will also contribute to further weakening, along with a lessening severe threat. ..Darrow.. 07/01/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 PM CDT Mon Jun 30 2025 Valid 010100Z - 011200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDDLE ATLANTIC...RED RIVER REGION OF THE SOUTHERN PLAINS...SOUTHWESTERN BORDER AREA...AND PACIFIC NORTHWEST... ...SUMMARY... Isolated strong, to locally severe, thunderstorms will persist for a few hours this evening. Damaging gusts are the primary concern. ...01z Update... Diurnal heating, and steepening of the boundary layer, has been the primary instigator for scattered convection across much of the CONUS this afternoon. Many areas have been efficiently overturned and with onset of nocturnal cooling, further stabilization is expected this evening. Even so, for the next few hours a few pockets of robust convection will likely persist. Moderate to strong buoyancy is noted across the Delmarva and the Red River region of southern OK/north TX. Deep convection may continue to generate locally strong winds until this activity weakens by mid evening. Isolated wind gusts may also accompany high-based convection across southeast AZ/southern NM, and near the OR/CA border. Boundary-layer cooling will also contribute to further weakening, along with a lessening severe threat. ..Darrow.. 07/01/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 PM CDT Mon Jun 30 2025 Valid 010100Z - 011200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDDLE ATLANTIC...RED RIVER REGION OF THE SOUTHERN PLAINS...SOUTHWESTERN BORDER AREA...AND PACIFIC NORTHWEST... ...SUMMARY... Isolated strong, to locally severe, thunderstorms will persist for a few hours this evening. Damaging gusts are the primary concern. ...01z Update... Diurnal heating, and steepening of the boundary layer, has been the primary instigator for scattered convection across much of the CONUS this afternoon. Many areas have been efficiently overturned and with onset of nocturnal cooling, further stabilization is expected this evening. Even so, for the next few hours a few pockets of robust convection will likely persist. Moderate to strong buoyancy is noted across the Delmarva and the Red River region of southern OK/north TX. Deep convection may continue to generate locally strong winds until this activity weakens by mid evening. Isolated wind gusts may also accompany high-based convection across southeast AZ/southern NM, and near the OR/CA border. Boundary-layer cooling will also contribute to further weakening, along with a lessening severe threat. ..Darrow.. 07/01/2025 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 PM CDT Mon Jun 30 2025 Valid 010100Z - 011200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDDLE ATLANTIC...RED RIVER REGION OF THE SOUTHERN PLAINS...SOUTHWESTERN BORDER AREA...AND PACIFIC NORTHWEST... ...SUMMARY... Isolated strong, to locally severe, thunderstorms will persist for a few hours this evening. Damaging gusts are the primary concern. ...01z Update... Diurnal heating, and steepening of the boundary layer, has been the primary instigator for scattered convection across much of the CONUS this afternoon. Many areas have been efficiently overturned and with onset of nocturnal cooling, further stabilization is expected this evening. Even so, for the next few hours a few pockets of robust convection will likely persist. Moderate to strong buoyancy is noted across the Delmarva and the Red River region of southern OK/north TX. Deep convection may continue to generate locally strong winds until this activity weakens by mid evening. Isolated wind gusts may also accompany high-based convection across southeast AZ/southern NM, and near the OR/CA border. Boundary-layer cooling will also contribute to further weakening, along with a lessening severe threat. ..Darrow.. 07/01/2025 Read more

MD 1528 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF NORTHERN CA AND SOUTHERN OR
Mesoscale Discussion 1528 NWS Storm Prediction Center Norman OK 0535 PM CDT Mon Jun 30 2025 Areas affected...portions of northern CA and southern OR Concerning...Severe potential...Watch unlikely Valid 302235Z - 010030Z Probability of Watch Issuance...20 percent SUMMARY...Scattered thunderstorm developing over the higher terrain will gradually expand in coverage/intensity this evening. Isolated damaging gusts and small hail are possible with the strongest storms. A WW is not anticipated, though convective trends will continue to be monitored. DISCUSSION...As of 2230 UTC, regional satellite and radar imagery showed initial thunderstorms have increased in cover/intensity across parts of northern CA and southern OR. Monsoon moisture being advected ahead of an upper low off the coast of central CA has resulted in ~1000 J/kg of MUCAPE atop very steep low-level lapse rates. The warm and unstable air mass will support additional storm development with continued ascent from a weak upper low, typical diurnal terrain circulations. As storms mature, southerly deep-layer shear around 30 kt may allow for some transient organization in the form of multicell clusters or weak supercells. The dry sub-cloud layer (deep mixing to near 500 mb) will promote strong downdrafts, capable of isolated severe gusts. Some small hail will also be possible with the stronger cores. Scattered storms will remain possible into this evening and overnight. Given the increase in convective coverage and the general environment, some severe risk could materialize. However, the limited potential for storm organization suggests a WW is not likely. ..Lyons/Bunting.. 06/30/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...REV...MFR...STO...PQR...EKA... LAT...LON 41752378 43482322 43642211 42712013 41312017 41122067 40622184 40502255 41752378 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

No watches are valid as of Mon Jun 30 22:38:01 UTC 2025.

MD 1528 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PORTIONS OF NORTHERN CA AND SOUTHERN OR
Mesoscale Discussion 1528 NWS Storm Prediction Center Norman OK 0535 PM CDT Mon Jun 30 2025 Areas affected...portions of northern CA and southern OR Concerning...Severe potential...Watch unlikely Valid 302235Z - 010030Z Probability of Watch Issuance...20 percent SUMMARY...Scattered thunderstorm developing over the higher terrain will gradually expand in coverage/intensity this evening. Isolated damaging gusts and small hail are possible with the strongest storms. A WW is not anticipated, though convective trends will continue to be monitored. DISCUSSION...As of 2230 UTC, regional satellite and radar imagery showed initial thunderstorms have increased in cover/intensity across parts of northern CA and southern OR. Monsoon moisture being advected ahead of an upper low off the coast of central CA has resulted in ~1000 J/kg of MUCAPE atop very steep low-level lapse rates. The warm and unstable air mass will support additional storm development with continued ascent from a weak upper low, typical diurnal terrain circulations. As storms mature, southerly deep-layer shear around 30 kt may allow for some transient organization in the form of multicell clusters or weak supercells. The dry sub-cloud layer (deep mixing to near 500 mb) will promote strong downdrafts, capable of isolated severe gusts. Some small hail will also be possible with the stronger cores. Scattered storms will remain possible into this evening and overnight. Given the increase in convective coverage and the general environment, some severe risk could materialize. However, the limited potential for storm organization suggests a WW is not likely. ..Lyons/Bunting.. 06/30/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...REV...MFR...STO...PQR...EKA... LAT...LON 41752378 43482322 43642211 42712013 41312017 41122067 40622184 40502255 41752378 MOST PROBABLE PEAK WIND GUST...55-70 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN Read more

No Mesoscale Discussions are in effect as of Mon Jun 30 22:33:02 UTC 2025.