SPC Jun 24, 2024 0600 UTC Day 2 Convective Outlook

1 year 2 months ago
SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Mon Jun 24 2024 Valid 251200Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE CENTRAL GREAT PLAINS INTO PARTS OF THE MIDWEST/GREAT LAKES... ...SUMMARY... Severe thunderstorms are possible from the central Great Plains into the Midwest and Great Lakes on Tuesday. ...Central/southern Great Plains into parts of the Midwest/Great Lakes... Due to a relatively wide range of potential outcomes on D1/Monday, uncertainty remains quite high regarding storm evolution on Tuesday. However, some organized severe-thunderstorm potential remains evident from parts of the central Great Plains into the Midwest and Great Lakes. Some threat could eventually spread southward into parts of the southern Plains, Ozarks, and Ohio Valley. An MCS may be ongoing Tuesday morning somewhere across the central Great Lakes vicinity, with other areas of elevated convection possibly ongoing across the region. At least an isolated severe threat may accompany the morning convection. Meanwhile, the cold front that moves through the Dakotas/Minnesota on Tuesday is forecast to take on a west-to-east orientation from eastern NE into central/northern IA to southern WI/northern IL, with potential for one or more outflow boundaries to the south of this front. Strong to locally extreme buoyancy (with MLCAPE above 3000 J/kg) will likely develop near/south of the front, in areas that are not overly influenced by morning convection. Outside the influence of any MCVs, midlevel west-northwesterly flow may remain rather modest across the warm sector, but strong enough to support sufficient effective shear for some storm organization. It is possible that some areas of ongoing morning convection will intensify through the day, with isolated to widely scattered development also possible along the primary front and any remnant outflow boundaries. Isolated high-based convection may also develop within a hot and well-mixed regime across western KS. The favorable thermodynamic environment will support hail potential with any more discrete convection. Some clustering/upscale growth will be possible, which could result in one or more corridors of greater damaging-wind potential. Some severe threat could eventually spread into parts of the Ohio Valley, Ozarks, and possibly the southern Plains, though the southern extent of the organized severe risk remains quite uncertain at this time. The current Slight Risk is a composite of multiple possible scenarios, and some adjustments will likely be required depending on guidance trends and evolution of D1/Monday convection. ..Dean.. 06/24/2024 Read more

SPC Jun 24, 2024 0600 UTC Day 2 Convective Outlook

1 year 2 months ago
SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1259 AM CDT Mon Jun 24 2024 Valid 251200Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE CENTRAL GREAT PLAINS INTO PARTS OF THE MIDWEST/GREAT LAKES... ...SUMMARY... Severe thunderstorms are possible from the central Great Plains into the Midwest and Great Lakes on Tuesday. ...Central/southern Great Plains into parts of the Midwest/Great Lakes... Due to a relatively wide range of potential outcomes on D1/Monday, uncertainty remains quite high regarding storm evolution on Tuesday. However, some organized severe-thunderstorm potential remains evident from parts of the central Great Plains into the Midwest and Great Lakes. Some threat could eventually spread southward into parts of the southern Plains, Ozarks, and Ohio Valley. An MCS may be ongoing Tuesday morning somewhere across the central Great Lakes vicinity, with other areas of elevated convection possibly ongoing across the region. At least an isolated severe threat may accompany the morning convection. Meanwhile, the cold front that moves through the Dakotas/Minnesota on Tuesday is forecast to take on a west-to-east orientation from eastern NE into central/northern IA to southern WI/northern IL, with potential for one or more outflow boundaries to the south of this front. Strong to locally extreme buoyancy (with MLCAPE above 3000 J/kg) will likely develop near/south of the front, in areas that are not overly influenced by morning convection. Outside the influence of any MCVs, midlevel west-northwesterly flow may remain rather modest across the warm sector, but strong enough to support sufficient effective shear for some storm organization. It is possible that some areas of ongoing morning convection will intensify through the day, with isolated to widely scattered development also possible along the primary front and any remnant outflow boundaries. Isolated high-based convection may also develop within a hot and well-mixed regime across western KS. The favorable thermodynamic environment will support hail potential with any more discrete convection. Some clustering/upscale growth will be possible, which could result in one or more corridors of greater damaging-wind potential. Some severe threat could eventually spread into parts of the Ohio Valley, Ozarks, and possibly the southern Plains, though the southern extent of the organized severe risk remains quite uncertain at this time. The current Slight Risk is a composite of multiple possible scenarios, and some adjustments will likely be required depending on guidance trends and evolution of D1/Monday convection. ..Dean.. 06/24/2024 Read more

SPC Jun 24, 2024 0600 UTC Day 1 Convective Outlook

1 year 2 months ago
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Mon Jun 24 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST TO THE CENTRAL PLAINS.... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, this afternoon and continuing overnight. A cluster of severe storms potentially capable of producing destructive wind gusts may develop over parts of Minnesota into Wisconsin though there remains significant uncertainty. ...Upper Midwest to the central Plains... A broad upper low with several embedded vort maxima and moderate west/southwestern flow over the Canadian prairies is forecast to move eastward and consolidate across portions of the Upper Midwest this afternoon and evening. Weak ascent will overspread a developing surface low and warm front lifting into the eastern Dakotas and western MN. Rich boundary-layer moisture (low 70s F surface dewpoints) is forecast to surge northward from the central Plains into the lower Red River Valley. Very warm temperatures (at the surface and aloft), steep mid-level lapse rates, and the returning moisture will prime an extremely unstable, but strongly capped troposphere, potentially supportive of all hazards. Multiple convective scenarios appear possible from late this afternoon through the overnight. Isolated surface-based thunderstorms may develop along the occluded front in eastern ND or near the triple point/warm front across northeast SD and western MN. While uncertain given the large inhibition, any storms that do form will likely organize into supercells given strong veering wind profiles and the very large buoyancy (MLCAPE >4000 J/kg). Large to very large hail, damaging winds and perhaps a tornado would be possible with any supercells, especially near the warm front with backed surface winds. Some CAM guidance suggests a cluster of storms could then track southeast along the warm front, potentially growing upscale into an MCS, with a damaging wind and hail risk into the overnight hours across the western Great Lakes. A second, potentially more significant, scenario may evolve if convection remains suppressed through the afternoon and instead develops along the southeastward surging cold front over the eastern Dakotas and western MN, or elevated storms intensify north of the warm front. With the 4000-5000 J/kg of MUCAPE present, rapid upscale growth into a damaging MCS/bow echo could result in the risk for widespread severe winds. This scenario remains highly uncertain given the warm temperatures aloft and unpredictable mesoscale storm interactions, but is reflected in several hi-res model solutions and by general pattern recognition. Should this occur, a swath of significant damaging winds may evolve along or just north of the buoyancy gradient across southern MN, southern/central WI and into portions of northern IL by 12z Tues. Considered an upgrade to level-3 Enhanced but uncertainty in storm development and evolution remains too high. ...Central Plains and Black Hills... Very warm surface temperatures are expected ahead of the weakening cold front across central NE and northern KS. Deeply mixed profiles may overcome very warm H7 temperatures to support widely scattered high-based storms. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support isolated severe gusts. The strongest updrafts may also be capable of producing some hail. High-based storms are also possible over the Black Hills where weak upslope flow is occurring behind the front. Limited moisture and only glancing upper-level support suggest storm coverage will remain isolated. Still, the deeply mixed air mass could support damaging gusts with any sustained storms. ...Carolinas... At the base of departing east coast trough, subtle height falls atop a warm and unstable air mass will support scattered afternoon thunderstorms across much of the eastern Carolinas along a weak surface cold front. Enhanced flow aloft and surface convergence near the front should be sufficient for transient storm organization into multi-cell clusters or a weak supercell. Steepening low-level lapse rates and the high PWAT air mass will favor heavily water and hail-loaded downdrafts capable of isolated damaging gusts. Storms should begin to move offshore by early evening ending the severe risk. ..Lyons/Wendt.. 06/24/2024 Read more

SPC Jun 24, 2024 0600 UTC Day 1 Convective Outlook

1 year 2 months ago
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Mon Jun 24 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST TO THE CENTRAL PLAINS.... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, this afternoon and continuing overnight. A cluster of severe storms potentially capable of producing destructive wind gusts may develop over parts of Minnesota into Wisconsin though there remains significant uncertainty. ...Upper Midwest to the central Plains... A broad upper low with several embedded vort maxima and moderate west/southwestern flow over the Canadian prairies is forecast to move eastward and consolidate across portions of the Upper Midwest this afternoon and evening. Weak ascent will overspread a developing surface low and warm front lifting into the eastern Dakotas and western MN. Rich boundary-layer moisture (low 70s F surface dewpoints) is forecast to surge northward from the central Plains into the lower Red River Valley. Very warm temperatures (at the surface and aloft), steep mid-level lapse rates, and the returning moisture will prime an extremely unstable, but strongly capped troposphere, potentially supportive of all hazards. Multiple convective scenarios appear possible from late this afternoon through the overnight. Isolated surface-based thunderstorms may develop along the occluded front in eastern ND or near the triple point/warm front across northeast SD and western MN. While uncertain given the large inhibition, any storms that do form will likely organize into supercells given strong veering wind profiles and the very large buoyancy (MLCAPE >4000 J/kg). Large to very large hail, damaging winds and perhaps a tornado would be possible with any supercells, especially near the warm front with backed surface winds. Some CAM guidance suggests a cluster of storms could then track southeast along the warm front, potentially growing upscale into an MCS, with a damaging wind and hail risk into the overnight hours across the western Great Lakes. A second, potentially more significant, scenario may evolve if convection remains suppressed through the afternoon and instead develops along the southeastward surging cold front over the eastern Dakotas and western MN, or elevated storms intensify north of the warm front. With the 4000-5000 J/kg of MUCAPE present, rapid upscale growth into a damaging MCS/bow echo could result in the risk for widespread severe winds. This scenario remains highly uncertain given the warm temperatures aloft and unpredictable mesoscale storm interactions, but is reflected in several hi-res model solutions and by general pattern recognition. Should this occur, a swath of significant damaging winds may evolve along or just north of the buoyancy gradient across southern MN, southern/central WI and into portions of northern IL by 12z Tues. Considered an upgrade to level-3 Enhanced but uncertainty in storm development and evolution remains too high. ...Central Plains and Black Hills... Very warm surface temperatures are expected ahead of the weakening cold front across central NE and northern KS. Deeply mixed profiles may overcome very warm H7 temperatures to support widely scattered high-based storms. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support isolated severe gusts. The strongest updrafts may also be capable of producing some hail. High-based storms are also possible over the Black Hills where weak upslope flow is occurring behind the front. Limited moisture and only glancing upper-level support suggest storm coverage will remain isolated. Still, the deeply mixed air mass could support damaging gusts with any sustained storms. ...Carolinas... At the base of departing east coast trough, subtle height falls atop a warm and unstable air mass will support scattered afternoon thunderstorms across much of the eastern Carolinas along a weak surface cold front. Enhanced flow aloft and surface convergence near the front should be sufficient for transient storm organization into multi-cell clusters or a weak supercell. Steepening low-level lapse rates and the high PWAT air mass will favor heavily water and hail-loaded downdrafts capable of isolated damaging gusts. Storms should begin to move offshore by early evening ending the severe risk. ..Lyons/Wendt.. 06/24/2024 Read more

SPC Jun 24, 2024 0600 UTC Day 1 Convective Outlook

1 year 2 months ago
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Mon Jun 24 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST TO THE CENTRAL PLAINS.... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, this afternoon and continuing overnight. A cluster of severe storms potentially capable of producing destructive wind gusts may develop over parts of Minnesota into Wisconsin though there remains significant uncertainty. ...Upper Midwest to the central Plains... A broad upper low with several embedded vort maxima and moderate west/southwestern flow over the Canadian prairies is forecast to move eastward and consolidate across portions of the Upper Midwest this afternoon and evening. Weak ascent will overspread a developing surface low and warm front lifting into the eastern Dakotas and western MN. Rich boundary-layer moisture (low 70s F surface dewpoints) is forecast to surge northward from the central Plains into the lower Red River Valley. Very warm temperatures (at the surface and aloft), steep mid-level lapse rates, and the returning moisture will prime an extremely unstable, but strongly capped troposphere, potentially supportive of all hazards. Multiple convective scenarios appear possible from late this afternoon through the overnight. Isolated surface-based thunderstorms may develop along the occluded front in eastern ND or near the triple point/warm front across northeast SD and western MN. While uncertain given the large inhibition, any storms that do form will likely organize into supercells given strong veering wind profiles and the very large buoyancy (MLCAPE >4000 J/kg). Large to very large hail, damaging winds and perhaps a tornado would be possible with any supercells, especially near the warm front with backed surface winds. Some CAM guidance suggests a cluster of storms could then track southeast along the warm front, potentially growing upscale into an MCS, with a damaging wind and hail risk into the overnight hours across the western Great Lakes. A second, potentially more significant, scenario may evolve if convection remains suppressed through the afternoon and instead develops along the southeastward surging cold front over the eastern Dakotas and western MN, or elevated storms intensify north of the warm front. With the 4000-5000 J/kg of MUCAPE present, rapid upscale growth into a damaging MCS/bow echo could result in the risk for widespread severe winds. This scenario remains highly uncertain given the warm temperatures aloft and unpredictable mesoscale storm interactions, but is reflected in several hi-res model solutions and by general pattern recognition. Should this occur, a swath of significant damaging winds may evolve along or just north of the buoyancy gradient across southern MN, southern/central WI and into portions of northern IL by 12z Tues. Considered an upgrade to level-3 Enhanced but uncertainty in storm development and evolution remains too high. ...Central Plains and Black Hills... Very warm surface temperatures are expected ahead of the weakening cold front across central NE and northern KS. Deeply mixed profiles may overcome very warm H7 temperatures to support widely scattered high-based storms. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support isolated severe gusts. The strongest updrafts may also be capable of producing some hail. High-based storms are also possible over the Black Hills where weak upslope flow is occurring behind the front. Limited moisture and only glancing upper-level support suggest storm coverage will remain isolated. Still, the deeply mixed air mass could support damaging gusts with any sustained storms. ...Carolinas... At the base of departing east coast trough, subtle height falls atop a warm and unstable air mass will support scattered afternoon thunderstorms across much of the eastern Carolinas along a weak surface cold front. Enhanced flow aloft and surface convergence near the front should be sufficient for transient storm organization into multi-cell clusters or a weak supercell. Steepening low-level lapse rates and the high PWAT air mass will favor heavily water and hail-loaded downdrafts capable of isolated damaging gusts. Storms should begin to move offshore by early evening ending the severe risk. ..Lyons/Wendt.. 06/24/2024 Read more

SPC Jun 24, 2024 0600 UTC Day 1 Convective Outlook

1 year 2 months ago
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Mon Jun 24 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST TO THE CENTRAL PLAINS.... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, this afternoon and continuing overnight. A cluster of severe storms potentially capable of producing destructive wind gusts may develop over parts of Minnesota into Wisconsin though there remains significant uncertainty. ...Upper Midwest to the central Plains... A broad upper low with several embedded vort maxima and moderate west/southwestern flow over the Canadian prairies is forecast to move eastward and consolidate across portions of the Upper Midwest this afternoon and evening. Weak ascent will overspread a developing surface low and warm front lifting into the eastern Dakotas and western MN. Rich boundary-layer moisture (low 70s F surface dewpoints) is forecast to surge northward from the central Plains into the lower Red River Valley. Very warm temperatures (at the surface and aloft), steep mid-level lapse rates, and the returning moisture will prime an extremely unstable, but strongly capped troposphere, potentially supportive of all hazards. Multiple convective scenarios appear possible from late this afternoon through the overnight. Isolated surface-based thunderstorms may develop along the occluded front in eastern ND or near the triple point/warm front across northeast SD and western MN. While uncertain given the large inhibition, any storms that do form will likely organize into supercells given strong veering wind profiles and the very large buoyancy (MLCAPE >4000 J/kg). Large to very large hail, damaging winds and perhaps a tornado would be possible with any supercells, especially near the warm front with backed surface winds. Some CAM guidance suggests a cluster of storms could then track southeast along the warm front, potentially growing upscale into an MCS, with a damaging wind and hail risk into the overnight hours across the western Great Lakes. A second, potentially more significant, scenario may evolve if convection remains suppressed through the afternoon and instead develops along the southeastward surging cold front over the eastern Dakotas and western MN, or elevated storms intensify north of the warm front. With the 4000-5000 J/kg of MUCAPE present, rapid upscale growth into a damaging MCS/bow echo could result in the risk for widespread severe winds. This scenario remains highly uncertain given the warm temperatures aloft and unpredictable mesoscale storm interactions, but is reflected in several hi-res model solutions and by general pattern recognition. Should this occur, a swath of significant damaging winds may evolve along or just north of the buoyancy gradient across southern MN, southern/central WI and into portions of northern IL by 12z Tues. Considered an upgrade to level-3 Enhanced but uncertainty in storm development and evolution remains too high. ...Central Plains and Black Hills... Very warm surface temperatures are expected ahead of the weakening cold front across central NE and northern KS. Deeply mixed profiles may overcome very warm H7 temperatures to support widely scattered high-based storms. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support isolated severe gusts. The strongest updrafts may also be capable of producing some hail. High-based storms are also possible over the Black Hills where weak upslope flow is occurring behind the front. Limited moisture and only glancing upper-level support suggest storm coverage will remain isolated. Still, the deeply mixed air mass could support damaging gusts with any sustained storms. ...Carolinas... At the base of departing east coast trough, subtle height falls atop a warm and unstable air mass will support scattered afternoon thunderstorms across much of the eastern Carolinas along a weak surface cold front. Enhanced flow aloft and surface convergence near the front should be sufficient for transient storm organization into multi-cell clusters or a weak supercell. Steepening low-level lapse rates and the high PWAT air mass will favor heavily water and hail-loaded downdrafts capable of isolated damaging gusts. Storms should begin to move offshore by early evening ending the severe risk. ..Lyons/Wendt.. 06/24/2024 Read more

SPC Jun 24, 2024 0600 UTC Day 1 Convective Outlook

1 year 2 months ago
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Mon Jun 24 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST TO THE CENTRAL PLAINS.... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, this afternoon and continuing overnight. A cluster of severe storms potentially capable of producing destructive wind gusts may develop over parts of Minnesota into Wisconsin though there remains significant uncertainty. ...Upper Midwest to the central Plains... A broad upper low with several embedded vort maxima and moderate west/southwestern flow over the Canadian prairies is forecast to move eastward and consolidate across portions of the Upper Midwest this afternoon and evening. Weak ascent will overspread a developing surface low and warm front lifting into the eastern Dakotas and western MN. Rich boundary-layer moisture (low 70s F surface dewpoints) is forecast to surge northward from the central Plains into the lower Red River Valley. Very warm temperatures (at the surface and aloft), steep mid-level lapse rates, and the returning moisture will prime an extremely unstable, but strongly capped troposphere, potentially supportive of all hazards. Multiple convective scenarios appear possible from late this afternoon through the overnight. Isolated surface-based thunderstorms may develop along the occluded front in eastern ND or near the triple point/warm front across northeast SD and western MN. While uncertain given the large inhibition, any storms that do form will likely organize into supercells given strong veering wind profiles and the very large buoyancy (MLCAPE >4000 J/kg). Large to very large hail, damaging winds and perhaps a tornado would be possible with any supercells, especially near the warm front with backed surface winds. Some CAM guidance suggests a cluster of storms could then track southeast along the warm front, potentially growing upscale into an MCS, with a damaging wind and hail risk into the overnight hours across the western Great Lakes. A second, potentially more significant, scenario may evolve if convection remains suppressed through the afternoon and instead develops along the southeastward surging cold front over the eastern Dakotas and western MN, or elevated storms intensify north of the warm front. With the 4000-5000 J/kg of MUCAPE present, rapid upscale growth into a damaging MCS/bow echo could result in the risk for widespread severe winds. This scenario remains highly uncertain given the warm temperatures aloft and unpredictable mesoscale storm interactions, but is reflected in several hi-res model solutions and by general pattern recognition. Should this occur, a swath of significant damaging winds may evolve along or just north of the buoyancy gradient across southern MN, southern/central WI and into portions of northern IL by 12z Tues. Considered an upgrade to level-3 Enhanced but uncertainty in storm development and evolution remains too high. ...Central Plains and Black Hills... Very warm surface temperatures are expected ahead of the weakening cold front across central NE and northern KS. Deeply mixed profiles may overcome very warm H7 temperatures to support widely scattered high-based storms. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support isolated severe gusts. The strongest updrafts may also be capable of producing some hail. High-based storms are also possible over the Black Hills where weak upslope flow is occurring behind the front. Limited moisture and only glancing upper-level support suggest storm coverage will remain isolated. Still, the deeply mixed air mass could support damaging gusts with any sustained storms. ...Carolinas... At the base of departing east coast trough, subtle height falls atop a warm and unstable air mass will support scattered afternoon thunderstorms across much of the eastern Carolinas along a weak surface cold front. Enhanced flow aloft and surface convergence near the front should be sufficient for transient storm organization into multi-cell clusters or a weak supercell. Steepening low-level lapse rates and the high PWAT air mass will favor heavily water and hail-loaded downdrafts capable of isolated damaging gusts. Storms should begin to move offshore by early evening ending the severe risk. ..Lyons/Wendt.. 06/24/2024 Read more

SPC Jun 24, 2024 0600 UTC Day 1 Convective Outlook

1 year 2 months ago
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Mon Jun 24 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST TO THE CENTRAL PLAINS.... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, this afternoon and continuing overnight. A cluster of severe storms potentially capable of producing destructive wind gusts may develop over parts of Minnesota into Wisconsin though there remains significant uncertainty. ...Upper Midwest to the central Plains... A broad upper low with several embedded vort maxima and moderate west/southwestern flow over the Canadian prairies is forecast to move eastward and consolidate across portions of the Upper Midwest this afternoon and evening. Weak ascent will overspread a developing surface low and warm front lifting into the eastern Dakotas and western MN. Rich boundary-layer moisture (low 70s F surface dewpoints) is forecast to surge northward from the central Plains into the lower Red River Valley. Very warm temperatures (at the surface and aloft), steep mid-level lapse rates, and the returning moisture will prime an extremely unstable, but strongly capped troposphere, potentially supportive of all hazards. Multiple convective scenarios appear possible from late this afternoon through the overnight. Isolated surface-based thunderstorms may develop along the occluded front in eastern ND or near the triple point/warm front across northeast SD and western MN. While uncertain given the large inhibition, any storms that do form will likely organize into supercells given strong veering wind profiles and the very large buoyancy (MLCAPE >4000 J/kg). Large to very large hail, damaging winds and perhaps a tornado would be possible with any supercells, especially near the warm front with backed surface winds. Some CAM guidance suggests a cluster of storms could then track southeast along the warm front, potentially growing upscale into an MCS, with a damaging wind and hail risk into the overnight hours across the western Great Lakes. A second, potentially more significant, scenario may evolve if convection remains suppressed through the afternoon and instead develops along the southeastward surging cold front over the eastern Dakotas and western MN, or elevated storms intensify north of the warm front. With the 4000-5000 J/kg of MUCAPE present, rapid upscale growth into a damaging MCS/bow echo could result in the risk for widespread severe winds. This scenario remains highly uncertain given the warm temperatures aloft and unpredictable mesoscale storm interactions, but is reflected in several hi-res model solutions and by general pattern recognition. Should this occur, a swath of significant damaging winds may evolve along or just north of the buoyancy gradient across southern MN, southern/central WI and into portions of northern IL by 12z Tues. Considered an upgrade to level-3 Enhanced but uncertainty in storm development and evolution remains too high. ...Central Plains and Black Hills... Very warm surface temperatures are expected ahead of the weakening cold front across central NE and northern KS. Deeply mixed profiles may overcome very warm H7 temperatures to support widely scattered high-based storms. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support isolated severe gusts. The strongest updrafts may also be capable of producing some hail. High-based storms are also possible over the Black Hills where weak upslope flow is occurring behind the front. Limited moisture and only glancing upper-level support suggest storm coverage will remain isolated. Still, the deeply mixed air mass could support damaging gusts with any sustained storms. ...Carolinas... At the base of departing east coast trough, subtle height falls atop a warm and unstable air mass will support scattered afternoon thunderstorms across much of the eastern Carolinas along a weak surface cold front. Enhanced flow aloft and surface convergence near the front should be sufficient for transient storm organization into multi-cell clusters or a weak supercell. Steepening low-level lapse rates and the high PWAT air mass will favor heavily water and hail-loaded downdrafts capable of isolated damaging gusts. Storms should begin to move offshore by early evening ending the severe risk. ..Lyons/Wendt.. 06/24/2024 Read more

SPC Jun 24, 2024 0600 UTC Day 1 Convective Outlook

1 year 2 months ago
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Mon Jun 24 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST TO THE CENTRAL PLAINS.... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, this afternoon and continuing overnight. A cluster of severe storms potentially capable of producing destructive wind gusts may develop over parts of Minnesota into Wisconsin though there remains significant uncertainty. ...Upper Midwest to the central Plains... A broad upper low with several embedded vort maxima and moderate west/southwestern flow over the Canadian prairies is forecast to move eastward and consolidate across portions of the Upper Midwest this afternoon and evening. Weak ascent will overspread a developing surface low and warm front lifting into the eastern Dakotas and western MN. Rich boundary-layer moisture (low 70s F surface dewpoints) is forecast to surge northward from the central Plains into the lower Red River Valley. Very warm temperatures (at the surface and aloft), steep mid-level lapse rates, and the returning moisture will prime an extremely unstable, but strongly capped troposphere, potentially supportive of all hazards. Multiple convective scenarios appear possible from late this afternoon through the overnight. Isolated surface-based thunderstorms may develop along the occluded front in eastern ND or near the triple point/warm front across northeast SD and western MN. While uncertain given the large inhibition, any storms that do form will likely organize into supercells given strong veering wind profiles and the very large buoyancy (MLCAPE >4000 J/kg). Large to very large hail, damaging winds and perhaps a tornado would be possible with any supercells, especially near the warm front with backed surface winds. Some CAM guidance suggests a cluster of storms could then track southeast along the warm front, potentially growing upscale into an MCS, with a damaging wind and hail risk into the overnight hours across the western Great Lakes. A second, potentially more significant, scenario may evolve if convection remains suppressed through the afternoon and instead develops along the southeastward surging cold front over the eastern Dakotas and western MN, or elevated storms intensify north of the warm front. With the 4000-5000 J/kg of MUCAPE present, rapid upscale growth into a damaging MCS/bow echo could result in the risk for widespread severe winds. This scenario remains highly uncertain given the warm temperatures aloft and unpredictable mesoscale storm interactions, but is reflected in several hi-res model solutions and by general pattern recognition. Should this occur, a swath of significant damaging winds may evolve along or just north of the buoyancy gradient across southern MN, southern/central WI and into portions of northern IL by 12z Tues. Considered an upgrade to level-3 Enhanced but uncertainty in storm development and evolution remains too high. ...Central Plains and Black Hills... Very warm surface temperatures are expected ahead of the weakening cold front across central NE and northern KS. Deeply mixed profiles may overcome very warm H7 temperatures to support widely scattered high-based storms. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support isolated severe gusts. The strongest updrafts may also be capable of producing some hail. High-based storms are also possible over the Black Hills where weak upslope flow is occurring behind the front. Limited moisture and only glancing upper-level support suggest storm coverage will remain isolated. Still, the deeply mixed air mass could support damaging gusts with any sustained storms. ...Carolinas... At the base of departing east coast trough, subtle height falls atop a warm and unstable air mass will support scattered afternoon thunderstorms across much of the eastern Carolinas along a weak surface cold front. Enhanced flow aloft and surface convergence near the front should be sufficient for transient storm organization into multi-cell clusters or a weak supercell. Steepening low-level lapse rates and the high PWAT air mass will favor heavily water and hail-loaded downdrafts capable of isolated damaging gusts. Storms should begin to move offshore by early evening ending the severe risk. ..Lyons/Wendt.. 06/24/2024 Read more

SPC Jun 24, 2024 0600 UTC Day 1 Convective Outlook

1 year 2 months ago
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Mon Jun 24 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST TO THE CENTRAL PLAINS.... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, this afternoon and continuing overnight. A cluster of severe storms potentially capable of producing destructive wind gusts may develop over parts of Minnesota into Wisconsin though there remains significant uncertainty. ...Upper Midwest to the central Plains... A broad upper low with several embedded vort maxima and moderate west/southwestern flow over the Canadian prairies is forecast to move eastward and consolidate across portions of the Upper Midwest this afternoon and evening. Weak ascent will overspread a developing surface low and warm front lifting into the eastern Dakotas and western MN. Rich boundary-layer moisture (low 70s F surface dewpoints) is forecast to surge northward from the central Plains into the lower Red River Valley. Very warm temperatures (at the surface and aloft), steep mid-level lapse rates, and the returning moisture will prime an extremely unstable, but strongly capped troposphere, potentially supportive of all hazards. Multiple convective scenarios appear possible from late this afternoon through the overnight. Isolated surface-based thunderstorms may develop along the occluded front in eastern ND or near the triple point/warm front across northeast SD and western MN. While uncertain given the large inhibition, any storms that do form will likely organize into supercells given strong veering wind profiles and the very large buoyancy (MLCAPE >4000 J/kg). Large to very large hail, damaging winds and perhaps a tornado would be possible with any supercells, especially near the warm front with backed surface winds. Some CAM guidance suggests a cluster of storms could then track southeast along the warm front, potentially growing upscale into an MCS, with a damaging wind and hail risk into the overnight hours across the western Great Lakes. A second, potentially more significant, scenario may evolve if convection remains suppressed through the afternoon and instead develops along the southeastward surging cold front over the eastern Dakotas and western MN, or elevated storms intensify north of the warm front. With the 4000-5000 J/kg of MUCAPE present, rapid upscale growth into a damaging MCS/bow echo could result in the risk for widespread severe winds. This scenario remains highly uncertain given the warm temperatures aloft and unpredictable mesoscale storm interactions, but is reflected in several hi-res model solutions and by general pattern recognition. Should this occur, a swath of significant damaging winds may evolve along or just north of the buoyancy gradient across southern MN, southern/central WI and into portions of northern IL by 12z Tues. Considered an upgrade to level-3 Enhanced but uncertainty in storm development and evolution remains too high. ...Central Plains and Black Hills... Very warm surface temperatures are expected ahead of the weakening cold front across central NE and northern KS. Deeply mixed profiles may overcome very warm H7 temperatures to support widely scattered high-based storms. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support isolated severe gusts. The strongest updrafts may also be capable of producing some hail. High-based storms are also possible over the Black Hills where weak upslope flow is occurring behind the front. Limited moisture and only glancing upper-level support suggest storm coverage will remain isolated. Still, the deeply mixed air mass could support damaging gusts with any sustained storms. ...Carolinas... At the base of departing east coast trough, subtle height falls atop a warm and unstable air mass will support scattered afternoon thunderstorms across much of the eastern Carolinas along a weak surface cold front. Enhanced flow aloft and surface convergence near the front should be sufficient for transient storm organization into multi-cell clusters or a weak supercell. Steepening low-level lapse rates and the high PWAT air mass will favor heavily water and hail-loaded downdrafts capable of isolated damaging gusts. Storms should begin to move offshore by early evening ending the severe risk. ..Lyons/Wendt.. 06/24/2024 Read more

SPC Jun 24, 2024 0600 UTC Day 1 Convective Outlook

1 year 2 months ago
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1258 AM CDT Mon Jun 24 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST TO THE CENTRAL PLAINS.... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, this afternoon and continuing overnight. A cluster of severe storms potentially capable of producing destructive wind gusts may develop over parts of Minnesota into Wisconsin though there remains significant uncertainty. ...Upper Midwest to the central Plains... A broad upper low with several embedded vort maxima and moderate west/southwestern flow over the Canadian prairies is forecast to move eastward and consolidate across portions of the Upper Midwest this afternoon and evening. Weak ascent will overspread a developing surface low and warm front lifting into the eastern Dakotas and western MN. Rich boundary-layer moisture (low 70s F surface dewpoints) is forecast to surge northward from the central Plains into the lower Red River Valley. Very warm temperatures (at the surface and aloft), steep mid-level lapse rates, and the returning moisture will prime an extremely unstable, but strongly capped troposphere, potentially supportive of all hazards. Multiple convective scenarios appear possible from late this afternoon through the overnight. Isolated surface-based thunderstorms may develop along the occluded front in eastern ND or near the triple point/warm front across northeast SD and western MN. While uncertain given the large inhibition, any storms that do form will likely organize into supercells given strong veering wind profiles and the very large buoyancy (MLCAPE >4000 J/kg). Large to very large hail, damaging winds and perhaps a tornado would be possible with any supercells, especially near the warm front with backed surface winds. Some CAM guidance suggests a cluster of storms could then track southeast along the warm front, potentially growing upscale into an MCS, with a damaging wind and hail risk into the overnight hours across the western Great Lakes. A second, potentially more significant, scenario may evolve if convection remains suppressed through the afternoon and instead develops along the southeastward surging cold front over the eastern Dakotas and western MN, or elevated storms intensify north of the warm front. With the 4000-5000 J/kg of MUCAPE present, rapid upscale growth into a damaging MCS/bow echo could result in the risk for widespread severe winds. This scenario remains highly uncertain given the warm temperatures aloft and unpredictable mesoscale storm interactions, but is reflected in several hi-res model solutions and by general pattern recognition. Should this occur, a swath of significant damaging winds may evolve along or just north of the buoyancy gradient across southern MN, southern/central WI and into portions of northern IL by 12z Tues. Considered an upgrade to level-3 Enhanced but uncertainty in storm development and evolution remains too high. ...Central Plains and Black Hills... Very warm surface temperatures are expected ahead of the weakening cold front across central NE and northern KS. Deeply mixed profiles may overcome very warm H7 temperatures to support widely scattered high-based storms. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support isolated severe gusts. The strongest updrafts may also be capable of producing some hail. High-based storms are also possible over the Black Hills where weak upslope flow is occurring behind the front. Limited moisture and only glancing upper-level support suggest storm coverage will remain isolated. Still, the deeply mixed air mass could support damaging gusts with any sustained storms. ...Carolinas... At the base of departing east coast trough, subtle height falls atop a warm and unstable air mass will support scattered afternoon thunderstorms across much of the eastern Carolinas along a weak surface cold front. Enhanced flow aloft and surface convergence near the front should be sufficient for transient storm organization into multi-cell clusters or a weak supercell. Steepening low-level lapse rates and the high PWAT air mass will favor heavily water and hail-loaded downdrafts capable of isolated damaging gusts. Storms should begin to move offshore by early evening ending the severe risk. ..Lyons/Wendt.. 06/24/2024 Read more

SPC MD 1390

1 year 2 months ago
MD 1390 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF NORTH CENTRAL NORTH DAKOTA
Mesoscale Discussion 1390 NWS Storm Prediction Center Norman OK 1032 PM CDT Sun Jun 23 2024 Areas affected...parts of north central North Dakota Concerning...Severe potential...Watch unlikely Valid 240332Z - 240600Z Probability of Watch Issuance...20 percent SUMMARY...Lingering isolated supercell development may approach the north central North Dakota international border area by 1-2 AM CDT, accompanied by continuing risk for large hail and locally strong surface gusts. But it seems probable that this activity will tend to weaken as it progresses south of the border overnight. DISCUSSION...The southernmost cell of an initial cluster of supercells over southern Saskatchewan has been maintaining considerable strength while steadily propagating east-southeastward within strongly sheared 35-40 kt west-southwesterly deep-layer mean flow. It appears that this is being supported be seasonably moist updraft inflow, rooted within large-scale ascent associated with low-level warm advection, above a stable boundary layer to the east of the lee surface trough, but still characterized by CAPE on the order of 1000-2000+ J/kg. Based on its current motion, it would begin propagating across the international border to the north of Minot by 06-07Z. However, the northern/northeastern periphery of a plume very warm and more strongly capping elevated mixed-layer air is also in the process of advecting across this region, downstream of a mid/upper trough progressing across the Canadian Rockies into the Canadian Prairies. This may tend to finally suppress any stronger convection attempting to cross the international border. ..Kerr/Gleason.. 06/24/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BIS... LAT...LON 49960439 49890138 49159975 48470071 49000288 49130456 49960439 Read more

SPC Severe Thunderstorm Watch 450

1 year 2 months ago
WW 450 SEVERE TSTM ND 240455Z - 241000Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 450 NWS Storm Prediction Center Norman OK 1155 PM CDT Sun Jun 23 2024 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of North-central North Dakota * Effective this Sunday night and Monday morning from 1155 PM until 500 AM CDT. * Primary threats include... Scattered large hail and isolated very large hail events to 2 inches in diameter possible Isolated damaging wind gusts to 70 mph possible SUMMARY...Supercells should pose some threat for severe hail around 1-2 inches in diameter as they move east-southeastward. The severe thunderstorm watch area is approximately along and 35 statute miles either side of a line from 75 miles west northwest of Minot ND to 65 miles east of Minot ND. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU0). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 2 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 29035. ...Gleason Read more

SPC MD 1389

1 year 2 months ago
MD 1389 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR PARTS OF NORTHEASTERN MONTANA
Mesoscale Discussion 1389 NWS Storm Prediction Center Norman OK 0658 PM CDT Sun Jun 23 2024 Areas affected...parts of northeastern Montana Concerning...Severe potential...Watch possible Valid 232358Z - 240230Z Probability of Watch Issuance...40 percent SUMMARY...Isolated supercell development appears possible near and north of the Missouri River through 8-11 PM MDT. It is not clear that a severe weather watch will be needed due to localized nature of the threat, but trends will continue to be monitored. DISCUSSION...At least attempts at sustained deep convective development appear underway west of Glasgow MT. This appears near the southern edge of the onset of mid-level height falls associated with an upstream short wave trough progressing across the Canadian and adjacent northern U.S. Rockies. At lower levels this is focused near/east of a weak surface low embedded within lee surface troughing, aided by lift associated with low-level convergence and warm advection. Near the northern periphery of a plume of very warm elevated mixed-layer air advecting northeast of the northern Rockies, the approach of convective temperatures may also be a contributing factor. Based on various model output, this convective development may be maintained into and through the 02-05Z time frame, though it may remain isolated in nature to the south of the Saskatchewan border. In the presence of strong deep-layer shear, beneath 50+ kt westerly flow in the 500-300 mb layer, the environment is supportive of an evolving supercell. A hot and deeply mixed boundary-layer appears characterized by CAPE in excess of 1000 J/kg, sufficient to support a risk for large hail and locally severe wind gusts. ..Kerr/Gleason.. 06/23/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GGW... LAT...LON 48690409 48160442 47830699 47950747 48250737 48570708 48820705 49050447 48690409 Read more