Severe Storms

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0234 PM CDT Tue Jul 01 2025 Valid 031200Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN HIGH PLAINS...UPPER MIDWEST INTO THE GREAT LAKES...AND THE NORTHEAST... ...SUMMARY... Scattered storms capable of large hail and severe wind gusts are forecast across the Northeast on Thursday. Isolated severe wind gusts are also possible in the Northern Plains and parts of the Upper Midwest into the Great Lakes. ...Synopsis... A mid-level trough will deepen over New England as an upper trough moves over the Midwest, and broad mid-level troughing with multiple embedded impulses, overspreads the U.S. west of the Rockies on Thursday. The East and West Coast upper troughs will encourage surface troughing across the Northeast and the Plains states, as well as weak surface low development over the Great Basin. Given the presence of seasonal low-level moisture, and expected diurnal heating, at least scattered thunderstorms will develop across much of the Interior West, into the Plains, Midwest, and East Coast regions. At least isolated strong to potentially severe storms could develop over parts of the northern CONUS, where appreciable vertical wind shear will overspread the warm, moist airmass to support organized thunderstorms. ...Northeast... As the surface trough progresses across the Northeast, deep-layer northwesterly flow will overspread the region. Diurnal heating of a seasonably moist boundary layer will foster modest buoyancy, with 500-1500 J/kg MLCAPE expected. As thunderstorms develop during the afternoon, they will encounter roughly 25-35 kts of effective bulk shear, characterized by elongated/straight hodographs. Multicells and short line segments should be the main storm modes, with isolated damaging gusts the primary threat with the stronger storms. ...Upper Midwest into the Great Lakes... A belt of 35-45 kt northwesterly flow on the back side of the East Coast upper trough will overspread the Great Lakes during the afternoon hours, where diurnal heating of a moist low-level airmass will destabilize the boundary layer. MLCAPE may exceed 2000 J/kg in spots (locally higher to 3000 J/kg toward southeast MN given 7.5+ C/km mid-level lapse rates farther to the west). Forecast soundings depict modestly curved and elongated hodographs, supporting multicells and perhaps supercells with some of the stronger storms. Isolated severe wind and hail may accompany the stronger storms. Greater severe probabilities may be needed in future outlooks if favorable trends in greater storm coverage are realized in later available guidance. ...Northern High Plains... A mid-level impulse will traverse the broader western upper troughing regime and eject into the northern High Plains Thursday afternoon. By this time, steep mid-level lapse rates will overspread upper 60s F dewpoints to promote moderate to locally strong instability, with MLCAPE exceeding 3000 J/kg. Modest turning and strengthening of the winds with height will support elongated hodographs with slight low-level curvature, which will support multicells and splitting supercells given the aforementioned buoyancy. The storms are forecast to be isolated in coverage, with a few instances of severe wind and hail expected. ..Squitieri.. 07/01/2025 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0234 PM CDT Tue Jul 01 2025 Valid 031200Z - 041200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE NORTHERN HIGH PLAINS...UPPER MIDWEST INTO THE GREAT LAKES...AND THE NORTHEAST... ...SUMMARY... Scattered storms capable of large hail and severe wind gusts are forecast across the Northeast on Thursday. Isolated severe wind gusts are also possible in the Northern Plains and parts of the Upper Midwest into the Great Lakes. ...Synopsis... A mid-level trough will deepen over New England as an upper trough moves over the Midwest, and broad mid-level troughing with multiple embedded impulses, overspreads the U.S. west of the Rockies on Thursday. The East and West Coast upper troughs will encourage surface troughing across the Northeast and the Plains states, as well as weak surface low development over the Great Basin. Given the presence of seasonal low-level moisture, and expected diurnal heating, at least scattered thunderstorms will develop across much of the Interior West, into the Plains, Midwest, and East Coast regions. At least isolated strong to potentially severe storms could develop over parts of the northern CONUS, where appreciable vertical wind shear will overspread the warm, moist airmass to support organized thunderstorms. ...Northeast... As the surface trough progresses across the Northeast, deep-layer northwesterly flow will overspread the region. Diurnal heating of a seasonably moist boundary layer will foster modest buoyancy, with 500-1500 J/kg MLCAPE expected. As thunderstorms develop during the afternoon, they will encounter roughly 25-35 kts of effective bulk shear, characterized by elongated/straight hodographs. Multicells and short line segments should be the main storm modes, with isolated damaging gusts the primary threat with the stronger storms. ...Upper Midwest into the Great Lakes... A belt of 35-45 kt northwesterly flow on the back side of the East Coast upper trough will overspread the Great Lakes during the afternoon hours, where diurnal heating of a moist low-level airmass will destabilize the boundary layer. MLCAPE may exceed 2000 J/kg in spots (locally higher to 3000 J/kg toward southeast MN given 7.5+ C/km mid-level lapse rates farther to the west). Forecast soundings depict modestly curved and elongated hodographs, supporting multicells and perhaps supercells with some of the stronger storms. Isolated severe wind and hail may accompany the stronger storms. Greater severe probabilities may be needed in future outlooks if favorable trends in greater storm coverage are realized in later available guidance. ...Northern High Plains... A mid-level impulse will traverse the broader western upper troughing regime and eject into the northern High Plains Thursday afternoon. By this time, steep mid-level lapse rates will overspread upper 60s F dewpoints to promote moderate to locally strong instability, with MLCAPE exceeding 3000 J/kg. Modest turning and strengthening of the winds with height will support elongated hodographs with slight low-level curvature, which will support multicells and splitting supercells given the aforementioned buoyancy. The storms are forecast to be isolated in coverage, with a few instances of severe wind and hail expected. ..Squitieri.. 07/01/2025 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Tue Jul 01 2025 Valid 012000Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...20z Update... A Marginal Risk was added across southwestern MT into central ID with this outlook. While instability is modest, lapse rates are steep and forecast soundings show characteristic inverted-v. This suggests that the widely scattered thunderstorm activity this afternoon will be capable of occasionally strong to severe winds, supporting addition of a 5% wind risk. Otherwise, the outlook remains unchanged. See previous discussion below for more information. ..Thornton.. 07/01/2025 .PREV DISCUSSION... /ISSUED 1104 AM CDT Tue Jul 01 2025/ ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Tue Jul 01 2025 Valid 012000Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...20z Update... A Marginal Risk was added across southwestern MT into central ID with this outlook. While instability is modest, lapse rates are steep and forecast soundings show characteristic inverted-v. This suggests that the widely scattered thunderstorm activity this afternoon will be capable of occasionally strong to severe winds, supporting addition of a 5% wind risk. Otherwise, the outlook remains unchanged. See previous discussion below for more information. ..Thornton.. 07/01/2025 .PREV DISCUSSION... /ISSUED 1104 AM CDT Tue Jul 01 2025/ ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Tue Jul 01 2025 Valid 012000Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...20z Update... A Marginal Risk was added across southwestern MT into central ID with this outlook. While instability is modest, lapse rates are steep and forecast soundings show characteristic inverted-v. This suggests that the widely scattered thunderstorm activity this afternoon will be capable of occasionally strong to severe winds, supporting addition of a 5% wind risk. Otherwise, the outlook remains unchanged. See previous discussion below for more information. ..Thornton.. 07/01/2025 .PREV DISCUSSION... /ISSUED 1104 AM CDT Tue Jul 01 2025/ ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Tue Jul 01 2025 Valid 012000Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...20z Update... A Marginal Risk was added across southwestern MT into central ID with this outlook. While instability is modest, lapse rates are steep and forecast soundings show characteristic inverted-v. This suggests that the widely scattered thunderstorm activity this afternoon will be capable of occasionally strong to severe winds, supporting addition of a 5% wind risk. Otherwise, the outlook remains unchanged. See previous discussion below for more information. ..Thornton.. 07/01/2025 .PREV DISCUSSION... /ISSUED 1104 AM CDT Tue Jul 01 2025/ ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Tue Jul 01 2025 Valid 012000Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...20z Update... A Marginal Risk was added across southwestern MT into central ID with this outlook. While instability is modest, lapse rates are steep and forecast soundings show characteristic inverted-v. This suggests that the widely scattered thunderstorm activity this afternoon will be capable of occasionally strong to severe winds, supporting addition of a 5% wind risk. Otherwise, the outlook remains unchanged. See previous discussion below for more information. ..Thornton.. 07/01/2025 .PREV DISCUSSION... /ISSUED 1104 AM CDT Tue Jul 01 2025/ ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Tue Jul 01 2025 Valid 012000Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...20z Update... A Marginal Risk was added across southwestern MT into central ID with this outlook. While instability is modest, lapse rates are steep and forecast soundings show characteristic inverted-v. This suggests that the widely scattered thunderstorm activity this afternoon will be capable of occasionally strong to severe winds, supporting addition of a 5% wind risk. Otherwise, the outlook remains unchanged. See previous discussion below for more information. ..Thornton.. 07/01/2025 .PREV DISCUSSION... /ISSUED 1104 AM CDT Tue Jul 01 2025/ ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Tue Jul 01 2025 Valid 012000Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...20z Update... A Marginal Risk was added across southwestern MT into central ID with this outlook. While instability is modest, lapse rates are steep and forecast soundings show characteristic inverted-v. This suggests that the widely scattered thunderstorm activity this afternoon will be capable of occasionally strong to severe winds, supporting addition of a 5% wind risk. Otherwise, the outlook remains unchanged. See previous discussion below for more information. ..Thornton.. 07/01/2025 .PREV DISCUSSION... /ISSUED 1104 AM CDT Tue Jul 01 2025/ ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Tue Jul 01 2025 Valid 012000Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...20z Update... A Marginal Risk was added across southwestern MT into central ID with this outlook. While instability is modest, lapse rates are steep and forecast soundings show characteristic inverted-v. This suggests that the widely scattered thunderstorm activity this afternoon will be capable of occasionally strong to severe winds, supporting addition of a 5% wind risk. Otherwise, the outlook remains unchanged. See previous discussion below for more information. ..Thornton.. 07/01/2025 .PREV DISCUSSION... /ISSUED 1104 AM CDT Tue Jul 01 2025/ ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Tue Jul 01 2025 Valid 012000Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...20z Update... A Marginal Risk was added across southwestern MT into central ID with this outlook. While instability is modest, lapse rates are steep and forecast soundings show characteristic inverted-v. This suggests that the widely scattered thunderstorm activity this afternoon will be capable of occasionally strong to severe winds, supporting addition of a 5% wind risk. Otherwise, the outlook remains unchanged. See previous discussion below for more information. ..Thornton.. 07/01/2025 .PREV DISCUSSION... /ISSUED 1104 AM CDT Tue Jul 01 2025/ ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Tue Jul 01 2025 Valid 012000Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...20z Update... A Marginal Risk was added across southwestern MT into central ID with this outlook. While instability is modest, lapse rates are steep and forecast soundings show characteristic inverted-v. This suggests that the widely scattered thunderstorm activity this afternoon will be capable of occasionally strong to severe winds, supporting addition of a 5% wind risk. Otherwise, the outlook remains unchanged. See previous discussion below for more information. ..Thornton.. 07/01/2025 .PREV DISCUSSION... /ISSUED 1104 AM CDT Tue Jul 01 2025/ ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Tue Jul 01 2025 Valid 012000Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...20z Update... A Marginal Risk was added across southwestern MT into central ID with this outlook. While instability is modest, lapse rates are steep and forecast soundings show characteristic inverted-v. This suggests that the widely scattered thunderstorm activity this afternoon will be capable of occasionally strong to severe winds, supporting addition of a 5% wind risk. Otherwise, the outlook remains unchanged. See previous discussion below for more information. ..Thornton.. 07/01/2025 .PREV DISCUSSION... /ISSUED 1104 AM CDT Tue Jul 01 2025/ ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Tue Jul 01 2025 Valid 012000Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...20z Update... A Marginal Risk was added across southwestern MT into central ID with this outlook. While instability is modest, lapse rates are steep and forecast soundings show characteristic inverted-v. This suggests that the widely scattered thunderstorm activity this afternoon will be capable of occasionally strong to severe winds, supporting addition of a 5% wind risk. Otherwise, the outlook remains unchanged. See previous discussion below for more information. ..Thornton.. 07/01/2025 .PREV DISCUSSION... /ISSUED 1104 AM CDT Tue Jul 01 2025/ ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Tue Jul 01 2025 Valid 012000Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...20z Update... A Marginal Risk was added across southwestern MT into central ID with this outlook. While instability is modest, lapse rates are steep and forecast soundings show characteristic inverted-v. This suggests that the widely scattered thunderstorm activity this afternoon will be capable of occasionally strong to severe winds, supporting addition of a 5% wind risk. Otherwise, the outlook remains unchanged. See previous discussion below for more information. ..Thornton.. 07/01/2025 .PREV DISCUSSION... /ISSUED 1104 AM CDT Tue Jul 01 2025/ ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Tue Jul 01 2025 Valid 012000Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...20z Update... A Marginal Risk was added across southwestern MT into central ID with this outlook. While instability is modest, lapse rates are steep and forecast soundings show characteristic inverted-v. This suggests that the widely scattered thunderstorm activity this afternoon will be capable of occasionally strong to severe winds, supporting addition of a 5% wind risk. Otherwise, the outlook remains unchanged. See previous discussion below for more information. ..Thornton.. 07/01/2025 .PREV DISCUSSION... /ISSUED 1104 AM CDT Tue Jul 01 2025/ ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Tue Jul 01 2025 Valid 012000Z - 021200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE MID-ATLANTIC REGION AND ACROSS WESTERN PORTIONS OF NEBRASKA AND SOUTH DAKOTA... ...SUMMARY... Scattered strong to severe storms are possible across parts of the Mid-Atlantic into the Northeast this afternoon/evening. A few severe thunderstorms are possible over western parts of Nebraska and South Dakota. ...20z Update... A Marginal Risk was added across southwestern MT into central ID with this outlook. While instability is modest, lapse rates are steep and forecast soundings show characteristic inverted-v. This suggests that the widely scattered thunderstorm activity this afternoon will be capable of occasionally strong to severe winds, supporting addition of a 5% wind risk. Otherwise, the outlook remains unchanged. See previous discussion below for more information. ..Thornton.. 07/01/2025 .PREV DISCUSSION... /ISSUED 1104 AM CDT Tue Jul 01 2025/ ...Mid-Atlantic into the Northeast... Recent satellite imagery shows a well-defined shortwave trough extending from western QC through the middle OH Valley into the Mid MS Valley. Regional radar imagery depicts showers and thunderstorms preceding this wave from across the mid/upper OH Valley, with the stronger storms occurring along an associated cold front that extends from far western NY southwestward across western PA and along the WV/OH border through eastern KY. The general expectation throughout the day is for this shortwave trough and associated cold front to progress eastward into the increasingly moist and unstable airmass downstream, promoting widespread thunderstorm development this afternoon. Moderate mid-level flow extends through the eastern periphery of this wave, with the strongest flow (i.e. around 40 kt at 500 mb) expected to move across NY and New England. Given the more northern trajectory of the stronger flow, there will be limited overlap between the strongest flow and the better buoyancy, which will remain farther south across the Mid-Atlantic. Even so, the overall environment will support some organization of storms into line segments/clusters. Scattered thunderstorms will increase in coverage with time and numerous thunderstorms are expected by mid-late afternoon while moving east from PA/WV in NJ/VA/MD. Recently issued MCD #1529 also addresses the severe potential in this region. More limited storm coverage is anticipated farther north. Strong to severe gusts (50-65 mph) are possible with the stronger downdrafts. ...Black Hills/SD into the Central High Plains... A weak shortwave trough is currently progressing through eastern MT and eastern WY, throughout the northern periphery of the upper ridging that extends from the southern Plains through the northern Rockies. This wave is forecast to continue eastward/southeastward, eventually interacting with the moderate low-level moisture expected to advect northward across western portions of KS, NE and SD. Ascent attendant to this wave will augment low-level convergence near an associated surface low to foster afternoon thunderstorm development. Low-level southerly flow veering to northwesterly aloft will foster moderate effective shear (i.e. 30 to 40 kt) and the potential for a couple of supercells. Large hail will be the primary risk with these storms. Some additional thunderstorms are possible later tonight across far southern ND and central/eastern SD as a strengthening low-level jet contributes to warm-air advection across a developing warm frontal zone. Moderate shear and steep mid-level lapse rates will support a few stronger storms capable of producing isolated large hail. ...Central Appalachians into the Southeast... Afternoon thunderstorms are expected across a large area from the central Appalachians and Carolinas southwestward into the Southeast, along or just ahead of a weak, eastward-progressing cold front. Limited vertical shear should promote less organized storms, although a few strong, water-loaded downdrafts capable of producing damaging winds are possible. Read more

WW 0481 Status Updates
STATUS REPORT ON WW 481 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 50 SE LBE TO 35 NNE CXY TO 30 SW AVP. FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1533. ..GRAMS..07/01/25 ATTN...WFO...LWX...PHI...AKQ...CTP...RNK... STATUS REPORT FOR WS 481 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS DEC001-003-005-012040- DE . DELAWARE COUNTIES INCLUDED ARE KENT NEW CASTLE SUSSEX DCC001-012040- DC . DISTRICT OF COLUMBIA COUNTIES INCLUDED ARE DISTRICT OF COLUMBIA MDC001-003-005-009-011-013-015-017-019-021-025-027-029-031-033- 035-037-039-041-043-045-047-510-012040- MD . MARYLAND COUNTIES INCLUDED ARE ALLEGANY ANNE ARUNDEL BALTIMORE Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0159 PM CDT Tue Jul 01 2025 Valid 021200Z - 031200Z ...Northwest... A mid-level trough and attendant accelerating mid-level flow will support stronger onshore flow into western OR/WA. Stronger gap winds through the Columbia Gorge along with enhanced downslope drying into the Columbia Basin will bring elevated fire weather conditions to the area Wednesday in conjunction with dry fuels. Thunderstorm development is expected again Wednesday across northern CA into southeastern/eastern OR. Northeast storm motions to the northeast of 25-30 mph will limit precipitation duration although ignition efficiency may be limited owing to limited fuel receptiveness, precluding dry thunderstorm highlights for Wednesday. ..Williams.. 07/01/2025 .PREV DISCUSSION... /ISSUED 0120 AM CDT Tue Jul 01 2025/ ...Synopsis... A mid-level trough slowly progressing across portions of central California will continue to provide southerly transport of monsoon moisture into portions of the Great Basin on Wednesday, while a shortwave trough located further north over British Columbia will provide support for dry/windy conditions across northern Oregon into southern Washington. ...Dry/Windy... Modest mid-level westerly/southwesterly flow, coupled with deep mixing of dry boundary layer profiles, will support at least Elevated fire-weather conditions across portions of northern Oregon into southern Washington. The strongest winds will be confined to portions of the Cascade gaps/Columbia Gorge, with ERCs across the region nearing or meeting the annual 90th percentiles. ...Dry Thunderstorms... A mix of wet and dry thunderstorms will be possible from east-central Nevada into western Utah, and portions of far southeast Idaho into far western Wyoming. Fuels across significant portions of the Great Basin exceed the 98th annual percentiles, and a combination of low to modest total precipitable water vapor content and 0 - 6 km mean wind speeds ranging from 15 - 25 MPH will result in low precipitation efficiency with thunderstorm updrafts. This will support potential lightning ignitions, particularly with fast moving cells and on the edges of the most intense downdraft cores. ...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 0159 PM CDT Tue Jul 01 2025 Valid 021200Z - 031200Z ...Northwest... A mid-level trough and attendant accelerating mid-level flow will support stronger onshore flow into western OR/WA. Stronger gap winds through the Columbia Gorge along with enhanced downslope drying into the Columbia Basin will bring elevated fire weather conditions to the area Wednesday in conjunction with dry fuels. Thunderstorm development is expected again Wednesday across northern CA into southeastern/eastern OR. Northeast storm motions to the northeast of 25-30 mph will limit precipitation duration although ignition efficiency may be limited owing to limited fuel receptiveness, precluding dry thunderstorm highlights for Wednesday. ..Williams.. 07/01/2025 .PREV DISCUSSION... /ISSUED 0120 AM CDT Tue Jul 01 2025/ ...Synopsis... A mid-level trough slowly progressing across portions of central California will continue to provide southerly transport of monsoon moisture into portions of the Great Basin on Wednesday, while a shortwave trough located further north over British Columbia will provide support for dry/windy conditions across northern Oregon into southern Washington. ...Dry/Windy... Modest mid-level westerly/southwesterly flow, coupled with deep mixing of dry boundary layer profiles, will support at least Elevated fire-weather conditions across portions of northern Oregon into southern Washington. The strongest winds will be confined to portions of the Cascade gaps/Columbia Gorge, with ERCs across the region nearing or meeting the annual 90th percentiles. ...Dry Thunderstorms... A mix of wet and dry thunderstorms will be possible from east-central Nevada into western Utah, and portions of far southeast Idaho into far western Wyoming. Fuels across significant portions of the Great Basin exceed the 98th annual percentiles, and a combination of low to modest total precipitable water vapor content and 0 - 6 km mean wind speeds ranging from 15 - 25 MPH will result in low precipitation efficiency with thunderstorm updrafts. This will support potential lightning ignitions, particularly with fast moving cells and on the edges of the most intense downdraft cores. ...Please see www.spc.noaa.gov/fire for graphic product... Read more