Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z The previous forecast remains on track with only minor adjustments made based on recent trends in guidance. Ensemble solutions continue to suggest low probability for critical fire weather conditions, but reasonably high potential for elevated conditions within the highlighted regions. See the previous discussion for additional details. ..Moore.. 06/23/2024 .PREV DISCUSSION... /ISSUED 0125 AM CDT Sun Jun 23 2024/ ...Synopsis... The upper-level trough in the Northwest will move into the northern Rockies and Plains through the day on Monday. A surface front will have moved through the Northwest and stalled in the northern Great Basin. Surface winds from the lee of the northern Sierra into the Snake River Plain will be modestly enhanced ahead of the front. Furthermore, lingering stronger mid-level winds will remain across southern Idaho. These features will promote dry and breezy conditions during the afternoon. RH of 10-20% will be possible. Winds of 15-20 mph can be expected, though speeds approaching 25 mph may occur in the Snake River Plain. Elevated fire weather is expected in these areas for a few hours during the afternoon. Locally critical is again possible in the Snake Plain, but fuels will continue to mitigate greater risk. ...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 0200 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z The previous forecast remains on track with only minor adjustments made based on recent trends in guidance. Ensemble solutions continue to suggest low probability for critical fire weather conditions, but reasonably high potential for elevated conditions within the highlighted regions. See the previous discussion for additional details. ..Moore.. 06/23/2024 .PREV DISCUSSION... /ISSUED 0125 AM CDT Sun Jun 23 2024/ ...Synopsis... The upper-level trough in the Northwest will move into the northern Rockies and Plains through the day on Monday. A surface front will have moved through the Northwest and stalled in the northern Great Basin. Surface winds from the lee of the northern Sierra into the Snake River Plain will be modestly enhanced ahead of the front. Furthermore, lingering stronger mid-level winds will remain across southern Idaho. These features will promote dry and breezy conditions during the afternoon. RH of 10-20% will be possible. Winds of 15-20 mph can be expected, though speeds approaching 25 mph may occur in the Snake River Plain. Elevated fire weather is expected in these areas for a few hours during the afternoon. Locally critical is again possible in the Snake Plain, but fuels will continue to mitigate greater risk. ...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 0200 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z The previous forecast remains on track with only minor adjustments made based on recent trends in guidance. Ensemble solutions continue to suggest low probability for critical fire weather conditions, but reasonably high potential for elevated conditions within the highlighted regions. See the previous discussion for additional details. ..Moore.. 06/23/2024 .PREV DISCUSSION... /ISSUED 0125 AM CDT Sun Jun 23 2024/ ...Synopsis... The upper-level trough in the Northwest will move into the northern Rockies and Plains through the day on Monday. A surface front will have moved through the Northwest and stalled in the northern Great Basin. Surface winds from the lee of the northern Sierra into the Snake River Plain will be modestly enhanced ahead of the front. Furthermore, lingering stronger mid-level winds will remain across southern Idaho. These features will promote dry and breezy conditions during the afternoon. RH of 10-20% will be possible. Winds of 15-20 mph can be expected, though speeds approaching 25 mph may occur in the Snake River Plain. Elevated fire weather is expected in these areas for a few hours during the afternoon. Locally critical is again possible in the Snake Plain, but fuels will continue to mitigate greater risk. ...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 0200 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z The previous forecast remains on track with only minor adjustments made based on recent trends in guidance. Ensemble solutions continue to suggest low probability for critical fire weather conditions, but reasonably high potential for elevated conditions within the highlighted regions. See the previous discussion for additional details. ..Moore.. 06/23/2024 .PREV DISCUSSION... /ISSUED 0125 AM CDT Sun Jun 23 2024/ ...Synopsis... The upper-level trough in the Northwest will move into the northern Rockies and Plains through the day on Monday. A surface front will have moved through the Northwest and stalled in the northern Great Basin. Surface winds from the lee of the northern Sierra into the Snake River Plain will be modestly enhanced ahead of the front. Furthermore, lingering stronger mid-level winds will remain across southern Idaho. These features will promote dry and breezy conditions during the afternoon. RH of 10-20% will be possible. Winds of 15-20 mph can be expected, though speeds approaching 25 mph may occur in the Snake River Plain. Elevated fire weather is expected in these areas for a few hours during the afternoon. Locally critical is again possible in the Snake Plain, but fuels will continue to mitigate greater risk. ...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 0200 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z The previous forecast remains on track with only minor adjustments made based on recent trends in guidance. Ensemble solutions continue to suggest low probability for critical fire weather conditions, but reasonably high potential for elevated conditions within the highlighted regions. See the previous discussion for additional details. ..Moore.. 06/23/2024 .PREV DISCUSSION... /ISSUED 0125 AM CDT Sun Jun 23 2024/ ...Synopsis... The upper-level trough in the Northwest will move into the northern Rockies and Plains through the day on Monday. A surface front will have moved through the Northwest and stalled in the northern Great Basin. Surface winds from the lee of the northern Sierra into the Snake River Plain will be modestly enhanced ahead of the front. Furthermore, lingering stronger mid-level winds will remain across southern Idaho. These features will promote dry and breezy conditions during the afternoon. RH of 10-20% will be possible. Winds of 15-20 mph can be expected, though speeds approaching 25 mph may occur in the Snake River Plain. Elevated fire weather is expected in these areas for a few hours during the afternoon. Locally critical is again possible in the Snake Plain, but fuels will continue to mitigate greater risk. ...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 0200 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z The previous forecast remains on track with only minor adjustments made based on recent trends in guidance. Ensemble solutions continue to suggest low probability for critical fire weather conditions, but reasonably high potential for elevated conditions within the highlighted regions. See the previous discussion for additional details. ..Moore.. 06/23/2024 .PREV DISCUSSION... /ISSUED 0125 AM CDT Sun Jun 23 2024/ ...Synopsis... The upper-level trough in the Northwest will move into the northern Rockies and Plains through the day on Monday. A surface front will have moved through the Northwest and stalled in the northern Great Basin. Surface winds from the lee of the northern Sierra into the Snake River Plain will be modestly enhanced ahead of the front. Furthermore, lingering stronger mid-level winds will remain across southern Idaho. These features will promote dry and breezy conditions during the afternoon. RH of 10-20% will be possible. Winds of 15-20 mph can be expected, though speeds approaching 25 mph may occur in the Snake River Plain. Elevated fire weather is expected in these areas for a few hours during the afternoon. Locally critical is again possible in the Snake Plain, but fuels will continue to mitigate greater risk. ...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 0200 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z The previous forecast remains on track with only minor adjustments made based on recent trends in guidance. Ensemble solutions continue to suggest low probability for critical fire weather conditions, but reasonably high potential for elevated conditions within the highlighted regions. See the previous discussion for additional details. ..Moore.. 06/23/2024 .PREV DISCUSSION... /ISSUED 0125 AM CDT Sun Jun 23 2024/ ...Synopsis... The upper-level trough in the Northwest will move into the northern Rockies and Plains through the day on Monday. A surface front will have moved through the Northwest and stalled in the northern Great Basin. Surface winds from the lee of the northern Sierra into the Snake River Plain will be modestly enhanced ahead of the front. Furthermore, lingering stronger mid-level winds will remain across southern Idaho. These features will promote dry and breezy conditions during the afternoon. RH of 10-20% will be possible. Winds of 15-20 mph can be expected, though speeds approaching 25 mph may occur in the Snake River Plain. Elevated fire weather is expected in these areas for a few hours during the afternoon. Locally critical is again possible in the Snake Plain, but fuels will continue to mitigate greater risk. ...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 0200 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z The previous forecast remains on track with only minor adjustments made based on recent trends in guidance. Ensemble solutions continue to suggest low probability for critical fire weather conditions, but reasonably high potential for elevated conditions within the highlighted regions. See the previous discussion for additional details. ..Moore.. 06/23/2024 .PREV DISCUSSION... /ISSUED 0125 AM CDT Sun Jun 23 2024/ ...Synopsis... The upper-level trough in the Northwest will move into the northern Rockies and Plains through the day on Monday. A surface front will have moved through the Northwest and stalled in the northern Great Basin. Surface winds from the lee of the northern Sierra into the Snake River Plain will be modestly enhanced ahead of the front. Furthermore, lingering stronger mid-level winds will remain across southern Idaho. These features will promote dry and breezy conditions during the afternoon. RH of 10-20% will be possible. Winds of 15-20 mph can be expected, though speeds approaching 25 mph may occur in the Snake River Plain. Elevated fire weather is expected in these areas for a few hours during the afternoon. Locally critical is again possible in the Snake Plain, but fuels will continue to mitigate greater risk. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, mainly from late afternoon Monday into Monday night. A low-probability scenario of a severe MCS producing destructive wind gusts is apparent, centered on central parts of Minnesota into Wisconsin. ...Upper Midwest... Confidence in tomorrow's severe evolution is low. A wide range in potential outcomes from a sporadic primarily elevated large hail threat to a derecho scenario are plausible. Primary change with this outlook is to add a significant severe wind area for the conditional potential of destructive wind gusts from an intense MCS. A shortwave trough should amplify somewhat over the southern Prairie Provinces, mainly during the latter portion of the period. This will induce weak mid-level height falls by Monday evening/night across northern portions of the Upper Midwest. Primary surface cyclone will similarly track east from southeast SK to far northwest ON. A north/south-oriented cold front attendant to this cyclone should push east across the northern Great Plains, with the trailing portion slowing and eventually stalling near the SD/NE border area. A very stout EML characterized by 700-mb temperatures of 14-16 C will inhibit surface-based warm sector development through much of the day, with remnant elevated convection from late D1 over ND potentially persisting on an isolated basis along the periphery of the EML, mainly over northern MN. Large to extreme buoyancy will develop, centered on eastern SD into western MN, with MLCAPE in excess of 4000 J/kg probable. Isolated late-afternoon to early-evening storm development will be possible near the cold front over eastern ND into west-central/northwest MN. Guidance differs greatly on whether this will occur or not given the stout capping to the southeast. A more probable scenario is for elevated convection to develop during the evening into the overnight as a low-level jet intensifies from the Mid-MO Valley towards Lake Superior. Guidance also differs on the evolution of the surface warm front into Monday evening/night with the 12Z NAM holding farther south and more pronounced with the baroclinic zone across central MN. Most other guidance advances the warm front deeper into northern MN. Given these spatial concerns along with the relatively weak forcing for ascent near/just after peak heating amid pronounced capping over the open warm sector, confidence is low in the most likely scenario of convective evolution. Isolated, very large hail will be possible given plentiful elevated MUCAPE and strengthening effective bulk shear. The 12Z HRW-ARW depicts a more ominous scenario with surface-based development over the Upper Red River Valley growing upscale into an intense, bowing MCS through central portions of MN/WI. This includes a signal for extreme rear-inflow jet development to around 95 kts at the mature stage over west-central WI. Other guidance suggests a later MCS may develop out of the elevated convection in north parts of MN/WI, and still other guidance suggests little, if any MCS development will occur. The decision has been made to defer on a categorical upgrade and await potentially more consistent guidance in later outlook cycles. ...Black Hills vicinity into parts of NE and western IA... The southern portion of the weak cold front should slow and stall near the SD/NE border area by early evening Monday. Strong heating in the vicinity of the boundary will support isolated to widely scattered high-based thunderstorm development. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support at least isolated severe gusts. The strongest updrafts may also be capable of producing some hail. ...Coastal Carolinas... A cold front is forecast to move across the coastal Carolinas vicinity, with scattered thunderstorm development expected during the afternoon. Moderate to locally strong prefrontal buoyancy (with MLCAPE of near/above 2000 J/kg) and effective shear generally around 25-30 kt will support potential for a few stronger multicells and perhaps a marginal supercell or two, with an attendant threat of locally damaging winds and hail. ..Grams.. 06/23/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, mainly from late afternoon Monday into Monday night. A low-probability scenario of a severe MCS producing destructive wind gusts is apparent, centered on central parts of Minnesota into Wisconsin. ...Upper Midwest... Confidence in tomorrow's severe evolution is low. A wide range in potential outcomes from a sporadic primarily elevated large hail threat to a derecho scenario are plausible. Primary change with this outlook is to add a significant severe wind area for the conditional potential of destructive wind gusts from an intense MCS. A shortwave trough should amplify somewhat over the southern Prairie Provinces, mainly during the latter portion of the period. This will induce weak mid-level height falls by Monday evening/night across northern portions of the Upper Midwest. Primary surface cyclone will similarly track east from southeast SK to far northwest ON. A north/south-oriented cold front attendant to this cyclone should push east across the northern Great Plains, with the trailing portion slowing and eventually stalling near the SD/NE border area. A very stout EML characterized by 700-mb temperatures of 14-16 C will inhibit surface-based warm sector development through much of the day, with remnant elevated convection from late D1 over ND potentially persisting on an isolated basis along the periphery of the EML, mainly over northern MN. Large to extreme buoyancy will develop, centered on eastern SD into western MN, with MLCAPE in excess of 4000 J/kg probable. Isolated late-afternoon to early-evening storm development will be possible near the cold front over eastern ND into west-central/northwest MN. Guidance differs greatly on whether this will occur or not given the stout capping to the southeast. A more probable scenario is for elevated convection to develop during the evening into the overnight as a low-level jet intensifies from the Mid-MO Valley towards Lake Superior. Guidance also differs on the evolution of the surface warm front into Monday evening/night with the 12Z NAM holding farther south and more pronounced with the baroclinic zone across central MN. Most other guidance advances the warm front deeper into northern MN. Given these spatial concerns along with the relatively weak forcing for ascent near/just after peak heating amid pronounced capping over the open warm sector, confidence is low in the most likely scenario of convective evolution. Isolated, very large hail will be possible given plentiful elevated MUCAPE and strengthening effective bulk shear. The 12Z HRW-ARW depicts a more ominous scenario with surface-based development over the Upper Red River Valley growing upscale into an intense, bowing MCS through central portions of MN/WI. This includes a signal for extreme rear-inflow jet development to around 95 kts at the mature stage over west-central WI. Other guidance suggests a later MCS may develop out of the elevated convection in north parts of MN/WI, and still other guidance suggests little, if any MCS development will occur. The decision has been made to defer on a categorical upgrade and await potentially more consistent guidance in later outlook cycles. ...Black Hills vicinity into parts of NE and western IA... The southern portion of the weak cold front should slow and stall near the SD/NE border area by early evening Monday. Strong heating in the vicinity of the boundary will support isolated to widely scattered high-based thunderstorm development. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support at least isolated severe gusts. The strongest updrafts may also be capable of producing some hail. ...Coastal Carolinas... A cold front is forecast to move across the coastal Carolinas vicinity, with scattered thunderstorm development expected during the afternoon. Moderate to locally strong prefrontal buoyancy (with MLCAPE of near/above 2000 J/kg) and effective shear generally around 25-30 kt will support potential for a few stronger multicells and perhaps a marginal supercell or two, with an attendant threat of locally damaging winds and hail. ..Grams.. 06/23/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, mainly from late afternoon Monday into Monday night. A low-probability scenario of a severe MCS producing destructive wind gusts is apparent, centered on central parts of Minnesota into Wisconsin. ...Upper Midwest... Confidence in tomorrow's severe evolution is low. A wide range in potential outcomes from a sporadic primarily elevated large hail threat to a derecho scenario are plausible. Primary change with this outlook is to add a significant severe wind area for the conditional potential of destructive wind gusts from an intense MCS. A shortwave trough should amplify somewhat over the southern Prairie Provinces, mainly during the latter portion of the period. This will induce weak mid-level height falls by Monday evening/night across northern portions of the Upper Midwest. Primary surface cyclone will similarly track east from southeast SK to far northwest ON. A north/south-oriented cold front attendant to this cyclone should push east across the northern Great Plains, with the trailing portion slowing and eventually stalling near the SD/NE border area. A very stout EML characterized by 700-mb temperatures of 14-16 C will inhibit surface-based warm sector development through much of the day, with remnant elevated convection from late D1 over ND potentially persisting on an isolated basis along the periphery of the EML, mainly over northern MN. Large to extreme buoyancy will develop, centered on eastern SD into western MN, with MLCAPE in excess of 4000 J/kg probable. Isolated late-afternoon to early-evening storm development will be possible near the cold front over eastern ND into west-central/northwest MN. Guidance differs greatly on whether this will occur or not given the stout capping to the southeast. A more probable scenario is for elevated convection to develop during the evening into the overnight as a low-level jet intensifies from the Mid-MO Valley towards Lake Superior. Guidance also differs on the evolution of the surface warm front into Monday evening/night with the 12Z NAM holding farther south and more pronounced with the baroclinic zone across central MN. Most other guidance advances the warm front deeper into northern MN. Given these spatial concerns along with the relatively weak forcing for ascent near/just after peak heating amid pronounced capping over the open warm sector, confidence is low in the most likely scenario of convective evolution. Isolated, very large hail will be possible given plentiful elevated MUCAPE and strengthening effective bulk shear. The 12Z HRW-ARW depicts a more ominous scenario with surface-based development over the Upper Red River Valley growing upscale into an intense, bowing MCS through central portions of MN/WI. This includes a signal for extreme rear-inflow jet development to around 95 kts at the mature stage over west-central WI. Other guidance suggests a later MCS may develop out of the elevated convection in north parts of MN/WI, and still other guidance suggests little, if any MCS development will occur. The decision has been made to defer on a categorical upgrade and await potentially more consistent guidance in later outlook cycles. ...Black Hills vicinity into parts of NE and western IA... The southern portion of the weak cold front should slow and stall near the SD/NE border area by early evening Monday. Strong heating in the vicinity of the boundary will support isolated to widely scattered high-based thunderstorm development. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support at least isolated severe gusts. The strongest updrafts may also be capable of producing some hail. ...Coastal Carolinas... A cold front is forecast to move across the coastal Carolinas vicinity, with scattered thunderstorm development expected during the afternoon. Moderate to locally strong prefrontal buoyancy (with MLCAPE of near/above 2000 J/kg) and effective shear generally around 25-30 kt will support potential for a few stronger multicells and perhaps a marginal supercell or two, with an attendant threat of locally damaging winds and hail. ..Grams.. 06/23/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, mainly from late afternoon Monday into Monday night. A low-probability scenario of a severe MCS producing destructive wind gusts is apparent, centered on central parts of Minnesota into Wisconsin. ...Upper Midwest... Confidence in tomorrow's severe evolution is low. A wide range in potential outcomes from a sporadic primarily elevated large hail threat to a derecho scenario are plausible. Primary change with this outlook is to add a significant severe wind area for the conditional potential of destructive wind gusts from an intense MCS. A shortwave trough should amplify somewhat over the southern Prairie Provinces, mainly during the latter portion of the period. This will induce weak mid-level height falls by Monday evening/night across northern portions of the Upper Midwest. Primary surface cyclone will similarly track east from southeast SK to far northwest ON. A north/south-oriented cold front attendant to this cyclone should push east across the northern Great Plains, with the trailing portion slowing and eventually stalling near the SD/NE border area. A very stout EML characterized by 700-mb temperatures of 14-16 C will inhibit surface-based warm sector development through much of the day, with remnant elevated convection from late D1 over ND potentially persisting on an isolated basis along the periphery of the EML, mainly over northern MN. Large to extreme buoyancy will develop, centered on eastern SD into western MN, with MLCAPE in excess of 4000 J/kg probable. Isolated late-afternoon to early-evening storm development will be possible near the cold front over eastern ND into west-central/northwest MN. Guidance differs greatly on whether this will occur or not given the stout capping to the southeast. A more probable scenario is for elevated convection to develop during the evening into the overnight as a low-level jet intensifies from the Mid-MO Valley towards Lake Superior. Guidance also differs on the evolution of the surface warm front into Monday evening/night with the 12Z NAM holding farther south and more pronounced with the baroclinic zone across central MN. Most other guidance advances the warm front deeper into northern MN. Given these spatial concerns along with the relatively weak forcing for ascent near/just after peak heating amid pronounced capping over the open warm sector, confidence is low in the most likely scenario of convective evolution. Isolated, very large hail will be possible given plentiful elevated MUCAPE and strengthening effective bulk shear. The 12Z HRW-ARW depicts a more ominous scenario with surface-based development over the Upper Red River Valley growing upscale into an intense, bowing MCS through central portions of MN/WI. This includes a signal for extreme rear-inflow jet development to around 95 kts at the mature stage over west-central WI. Other guidance suggests a later MCS may develop out of the elevated convection in north parts of MN/WI, and still other guidance suggests little, if any MCS development will occur. The decision has been made to defer on a categorical upgrade and await potentially more consistent guidance in later outlook cycles. ...Black Hills vicinity into parts of NE and western IA... The southern portion of the weak cold front should slow and stall near the SD/NE border area by early evening Monday. Strong heating in the vicinity of the boundary will support isolated to widely scattered high-based thunderstorm development. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support at least isolated severe gusts. The strongest updrafts may also be capable of producing some hail. ...Coastal Carolinas... A cold front is forecast to move across the coastal Carolinas vicinity, with scattered thunderstorm development expected during the afternoon. Moderate to locally strong prefrontal buoyancy (with MLCAPE of near/above 2000 J/kg) and effective shear generally around 25-30 kt will support potential for a few stronger multicells and perhaps a marginal supercell or two, with an attendant threat of locally damaging winds and hail. ..Grams.. 06/23/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, mainly from late afternoon Monday into Monday night. A low-probability scenario of a severe MCS producing destructive wind gusts is apparent, centered on central parts of Minnesota into Wisconsin. ...Upper Midwest... Confidence in tomorrow's severe evolution is low. A wide range in potential outcomes from a sporadic primarily elevated large hail threat to a derecho scenario are plausible. Primary change with this outlook is to add a significant severe wind area for the conditional potential of destructive wind gusts from an intense MCS. A shortwave trough should amplify somewhat over the southern Prairie Provinces, mainly during the latter portion of the period. This will induce weak mid-level height falls by Monday evening/night across northern portions of the Upper Midwest. Primary surface cyclone will similarly track east from southeast SK to far northwest ON. A north/south-oriented cold front attendant to this cyclone should push east across the northern Great Plains, with the trailing portion slowing and eventually stalling near the SD/NE border area. A very stout EML characterized by 700-mb temperatures of 14-16 C will inhibit surface-based warm sector development through much of the day, with remnant elevated convection from late D1 over ND potentially persisting on an isolated basis along the periphery of the EML, mainly over northern MN. Large to extreme buoyancy will develop, centered on eastern SD into western MN, with MLCAPE in excess of 4000 J/kg probable. Isolated late-afternoon to early-evening storm development will be possible near the cold front over eastern ND into west-central/northwest MN. Guidance differs greatly on whether this will occur or not given the stout capping to the southeast. A more probable scenario is for elevated convection to develop during the evening into the overnight as a low-level jet intensifies from the Mid-MO Valley towards Lake Superior. Guidance also differs on the evolution of the surface warm front into Monday evening/night with the 12Z NAM holding farther south and more pronounced with the baroclinic zone across central MN. Most other guidance advances the warm front deeper into northern MN. Given these spatial concerns along with the relatively weak forcing for ascent near/just after peak heating amid pronounced capping over the open warm sector, confidence is low in the most likely scenario of convective evolution. Isolated, very large hail will be possible given plentiful elevated MUCAPE and strengthening effective bulk shear. The 12Z HRW-ARW depicts a more ominous scenario with surface-based development over the Upper Red River Valley growing upscale into an intense, bowing MCS through central portions of MN/WI. This includes a signal for extreme rear-inflow jet development to around 95 kts at the mature stage over west-central WI. Other guidance suggests a later MCS may develop out of the elevated convection in north parts of MN/WI, and still other guidance suggests little, if any MCS development will occur. The decision has been made to defer on a categorical upgrade and await potentially more consistent guidance in later outlook cycles. ...Black Hills vicinity into parts of NE and western IA... The southern portion of the weak cold front should slow and stall near the SD/NE border area by early evening Monday. Strong heating in the vicinity of the boundary will support isolated to widely scattered high-based thunderstorm development. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support at least isolated severe gusts. The strongest updrafts may also be capable of producing some hail. ...Coastal Carolinas... A cold front is forecast to move across the coastal Carolinas vicinity, with scattered thunderstorm development expected during the afternoon. Moderate to locally strong prefrontal buoyancy (with MLCAPE of near/above 2000 J/kg) and effective shear generally around 25-30 kt will support potential for a few stronger multicells and perhaps a marginal supercell or two, with an attendant threat of locally damaging winds and hail. ..Grams.. 06/23/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, mainly from late afternoon Monday into Monday night. A low-probability scenario of a severe MCS producing destructive wind gusts is apparent, centered on central parts of Minnesota into Wisconsin. ...Upper Midwest... Confidence in tomorrow's severe evolution is low. A wide range in potential outcomes from a sporadic primarily elevated large hail threat to a derecho scenario are plausible. Primary change with this outlook is to add a significant severe wind area for the conditional potential of destructive wind gusts from an intense MCS. A shortwave trough should amplify somewhat over the southern Prairie Provinces, mainly during the latter portion of the period. This will induce weak mid-level height falls by Monday evening/night across northern portions of the Upper Midwest. Primary surface cyclone will similarly track east from southeast SK to far northwest ON. A north/south-oriented cold front attendant to this cyclone should push east across the northern Great Plains, with the trailing portion slowing and eventually stalling near the SD/NE border area. A very stout EML characterized by 700-mb temperatures of 14-16 C will inhibit surface-based warm sector development through much of the day, with remnant elevated convection from late D1 over ND potentially persisting on an isolated basis along the periphery of the EML, mainly over northern MN. Large to extreme buoyancy will develop, centered on eastern SD into western MN, with MLCAPE in excess of 4000 J/kg probable. Isolated late-afternoon to early-evening storm development will be possible near the cold front over eastern ND into west-central/northwest MN. Guidance differs greatly on whether this will occur or not given the stout capping to the southeast. A more probable scenario is for elevated convection to develop during the evening into the overnight as a low-level jet intensifies from the Mid-MO Valley towards Lake Superior. Guidance also differs on the evolution of the surface warm front into Monday evening/night with the 12Z NAM holding farther south and more pronounced with the baroclinic zone across central MN. Most other guidance advances the warm front deeper into northern MN. Given these spatial concerns along with the relatively weak forcing for ascent near/just after peak heating amid pronounced capping over the open warm sector, confidence is low in the most likely scenario of convective evolution. Isolated, very large hail will be possible given plentiful elevated MUCAPE and strengthening effective bulk shear. The 12Z HRW-ARW depicts a more ominous scenario with surface-based development over the Upper Red River Valley growing upscale into an intense, bowing MCS through central portions of MN/WI. This includes a signal for extreme rear-inflow jet development to around 95 kts at the mature stage over west-central WI. Other guidance suggests a later MCS may develop out of the elevated convection in north parts of MN/WI, and still other guidance suggests little, if any MCS development will occur. The decision has been made to defer on a categorical upgrade and await potentially more consistent guidance in later outlook cycles. ...Black Hills vicinity into parts of NE and western IA... The southern portion of the weak cold front should slow and stall near the SD/NE border area by early evening Monday. Strong heating in the vicinity of the boundary will support isolated to widely scattered high-based thunderstorm development. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support at least isolated severe gusts. The strongest updrafts may also be capable of producing some hail. ...Coastal Carolinas... A cold front is forecast to move across the coastal Carolinas vicinity, with scattered thunderstorm development expected during the afternoon. Moderate to locally strong prefrontal buoyancy (with MLCAPE of near/above 2000 J/kg) and effective shear generally around 25-30 kt will support potential for a few stronger multicells and perhaps a marginal supercell or two, with an attendant threat of locally damaging winds and hail. ..Grams.. 06/23/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, mainly from late afternoon Monday into Monday night. A low-probability scenario of a severe MCS producing destructive wind gusts is apparent, centered on central parts of Minnesota into Wisconsin. ...Upper Midwest... Confidence in tomorrow's severe evolution is low. A wide range in potential outcomes from a sporadic primarily elevated large hail threat to a derecho scenario are plausible. Primary change with this outlook is to add a significant severe wind area for the conditional potential of destructive wind gusts from an intense MCS. A shortwave trough should amplify somewhat over the southern Prairie Provinces, mainly during the latter portion of the period. This will induce weak mid-level height falls by Monday evening/night across northern portions of the Upper Midwest. Primary surface cyclone will similarly track east from southeast SK to far northwest ON. A north/south-oriented cold front attendant to this cyclone should push east across the northern Great Plains, with the trailing portion slowing and eventually stalling near the SD/NE border area. A very stout EML characterized by 700-mb temperatures of 14-16 C will inhibit surface-based warm sector development through much of the day, with remnant elevated convection from late D1 over ND potentially persisting on an isolated basis along the periphery of the EML, mainly over northern MN. Large to extreme buoyancy will develop, centered on eastern SD into western MN, with MLCAPE in excess of 4000 J/kg probable. Isolated late-afternoon to early-evening storm development will be possible near the cold front over eastern ND into west-central/northwest MN. Guidance differs greatly on whether this will occur or not given the stout capping to the southeast. A more probable scenario is for elevated convection to develop during the evening into the overnight as a low-level jet intensifies from the Mid-MO Valley towards Lake Superior. Guidance also differs on the evolution of the surface warm front into Monday evening/night with the 12Z NAM holding farther south and more pronounced with the baroclinic zone across central MN. Most other guidance advances the warm front deeper into northern MN. Given these spatial concerns along with the relatively weak forcing for ascent near/just after peak heating amid pronounced capping over the open warm sector, confidence is low in the most likely scenario of convective evolution. Isolated, very large hail will be possible given plentiful elevated MUCAPE and strengthening effective bulk shear. The 12Z HRW-ARW depicts a more ominous scenario with surface-based development over the Upper Red River Valley growing upscale into an intense, bowing MCS through central portions of MN/WI. This includes a signal for extreme rear-inflow jet development to around 95 kts at the mature stage over west-central WI. Other guidance suggests a later MCS may develop out of the elevated convection in north parts of MN/WI, and still other guidance suggests little, if any MCS development will occur. The decision has been made to defer on a categorical upgrade and await potentially more consistent guidance in later outlook cycles. ...Black Hills vicinity into parts of NE and western IA... The southern portion of the weak cold front should slow and stall near the SD/NE border area by early evening Monday. Strong heating in the vicinity of the boundary will support isolated to widely scattered high-based thunderstorm development. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support at least isolated severe gusts. The strongest updrafts may also be capable of producing some hail. ...Coastal Carolinas... A cold front is forecast to move across the coastal Carolinas vicinity, with scattered thunderstorm development expected during the afternoon. Moderate to locally strong prefrontal buoyancy (with MLCAPE of near/above 2000 J/kg) and effective shear generally around 25-30 kt will support potential for a few stronger multicells and perhaps a marginal supercell or two, with an attendant threat of locally damaging winds and hail. ..Grams.. 06/23/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, mainly from late afternoon Monday into Monday night. A low-probability scenario of a severe MCS producing destructive wind gusts is apparent, centered on central parts of Minnesota into Wisconsin. ...Upper Midwest... Confidence in tomorrow's severe evolution is low. A wide range in potential outcomes from a sporadic primarily elevated large hail threat to a derecho scenario are plausible. Primary change with this outlook is to add a significant severe wind area for the conditional potential of destructive wind gusts from an intense MCS. A shortwave trough should amplify somewhat over the southern Prairie Provinces, mainly during the latter portion of the period. This will induce weak mid-level height falls by Monday evening/night across northern portions of the Upper Midwest. Primary surface cyclone will similarly track east from southeast SK to far northwest ON. A north/south-oriented cold front attendant to this cyclone should push east across the northern Great Plains, with the trailing portion slowing and eventually stalling near the SD/NE border area. A very stout EML characterized by 700-mb temperatures of 14-16 C will inhibit surface-based warm sector development through much of the day, with remnant elevated convection from late D1 over ND potentially persisting on an isolated basis along the periphery of the EML, mainly over northern MN. Large to extreme buoyancy will develop, centered on eastern SD into western MN, with MLCAPE in excess of 4000 J/kg probable. Isolated late-afternoon to early-evening storm development will be possible near the cold front over eastern ND into west-central/northwest MN. Guidance differs greatly on whether this will occur or not given the stout capping to the southeast. A more probable scenario is for elevated convection to develop during the evening into the overnight as a low-level jet intensifies from the Mid-MO Valley towards Lake Superior. Guidance also differs on the evolution of the surface warm front into Monday evening/night with the 12Z NAM holding farther south and more pronounced with the baroclinic zone across central MN. Most other guidance advances the warm front deeper into northern MN. Given these spatial concerns along with the relatively weak forcing for ascent near/just after peak heating amid pronounced capping over the open warm sector, confidence is low in the most likely scenario of convective evolution. Isolated, very large hail will be possible given plentiful elevated MUCAPE and strengthening effective bulk shear. The 12Z HRW-ARW depicts a more ominous scenario with surface-based development over the Upper Red River Valley growing upscale into an intense, bowing MCS through central portions of MN/WI. This includes a signal for extreme rear-inflow jet development to around 95 kts at the mature stage over west-central WI. Other guidance suggests a later MCS may develop out of the elevated convection in north parts of MN/WI, and still other guidance suggests little, if any MCS development will occur. The decision has been made to defer on a categorical upgrade and await potentially more consistent guidance in later outlook cycles. ...Black Hills vicinity into parts of NE and western IA... The southern portion of the weak cold front should slow and stall near the SD/NE border area by early evening Monday. Strong heating in the vicinity of the boundary will support isolated to widely scattered high-based thunderstorm development. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support at least isolated severe gusts. The strongest updrafts may also be capable of producing some hail. ...Coastal Carolinas... A cold front is forecast to move across the coastal Carolinas vicinity, with scattered thunderstorm development expected during the afternoon. Moderate to locally strong prefrontal buoyancy (with MLCAPE of near/above 2000 J/kg) and effective shear generally around 25-30 kt will support potential for a few stronger multicells and perhaps a marginal supercell or two, with an attendant threat of locally damaging winds and hail. ..Grams.. 06/23/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, mainly from late afternoon Monday into Monday night. A low-probability scenario of a severe MCS producing destructive wind gusts is apparent, centered on central parts of Minnesota into Wisconsin. ...Upper Midwest... Confidence in tomorrow's severe evolution is low. A wide range in potential outcomes from a sporadic primarily elevated large hail threat to a derecho scenario are plausible. Primary change with this outlook is to add a significant severe wind area for the conditional potential of destructive wind gusts from an intense MCS. A shortwave trough should amplify somewhat over the southern Prairie Provinces, mainly during the latter portion of the period. This will induce weak mid-level height falls by Monday evening/night across northern portions of the Upper Midwest. Primary surface cyclone will similarly track east from southeast SK to far northwest ON. A north/south-oriented cold front attendant to this cyclone should push east across the northern Great Plains, with the trailing portion slowing and eventually stalling near the SD/NE border area. A very stout EML characterized by 700-mb temperatures of 14-16 C will inhibit surface-based warm sector development through much of the day, with remnant elevated convection from late D1 over ND potentially persisting on an isolated basis along the periphery of the EML, mainly over northern MN. Large to extreme buoyancy will develop, centered on eastern SD into western MN, with MLCAPE in excess of 4000 J/kg probable. Isolated late-afternoon to early-evening storm development will be possible near the cold front over eastern ND into west-central/northwest MN. Guidance differs greatly on whether this will occur or not given the stout capping to the southeast. A more probable scenario is for elevated convection to develop during the evening into the overnight as a low-level jet intensifies from the Mid-MO Valley towards Lake Superior. Guidance also differs on the evolution of the surface warm front into Monday evening/night with the 12Z NAM holding farther south and more pronounced with the baroclinic zone across central MN. Most other guidance advances the warm front deeper into northern MN. Given these spatial concerns along with the relatively weak forcing for ascent near/just after peak heating amid pronounced capping over the open warm sector, confidence is low in the most likely scenario of convective evolution. Isolated, very large hail will be possible given plentiful elevated MUCAPE and strengthening effective bulk shear. The 12Z HRW-ARW depicts a more ominous scenario with surface-based development over the Upper Red River Valley growing upscale into an intense, bowing MCS through central portions of MN/WI. This includes a signal for extreme rear-inflow jet development to around 95 kts at the mature stage over west-central WI. Other guidance suggests a later MCS may develop out of the elevated convection in north parts of MN/WI, and still other guidance suggests little, if any MCS development will occur. The decision has been made to defer on a categorical upgrade and await potentially more consistent guidance in later outlook cycles. ...Black Hills vicinity into parts of NE and western IA... The southern portion of the weak cold front should slow and stall near the SD/NE border area by early evening Monday. Strong heating in the vicinity of the boundary will support isolated to widely scattered high-based thunderstorm development. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support at least isolated severe gusts. The strongest updrafts may also be capable of producing some hail. ...Coastal Carolinas... A cold front is forecast to move across the coastal Carolinas vicinity, with scattered thunderstorm development expected during the afternoon. Moderate to locally strong prefrontal buoyancy (with MLCAPE of near/above 2000 J/kg) and effective shear generally around 25-30 kt will support potential for a few stronger multicells and perhaps a marginal supercell or two, with an attendant threat of locally damaging winds and hail. ..Grams.. 06/23/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, mainly from late afternoon Monday into Monday night. A low-probability scenario of a severe MCS producing destructive wind gusts is apparent, centered on central parts of Minnesota into Wisconsin. ...Upper Midwest... Confidence in tomorrow's severe evolution is low. A wide range in potential outcomes from a sporadic primarily elevated large hail threat to a derecho scenario are plausible. Primary change with this outlook is to add a significant severe wind area for the conditional potential of destructive wind gusts from an intense MCS. A shortwave trough should amplify somewhat over the southern Prairie Provinces, mainly during the latter portion of the period. This will induce weak mid-level height falls by Monday evening/night across northern portions of the Upper Midwest. Primary surface cyclone will similarly track east from southeast SK to far northwest ON. A north/south-oriented cold front attendant to this cyclone should push east across the northern Great Plains, with the trailing portion slowing and eventually stalling near the SD/NE border area. A very stout EML characterized by 700-mb temperatures of 14-16 C will inhibit surface-based warm sector development through much of the day, with remnant elevated convection from late D1 over ND potentially persisting on an isolated basis along the periphery of the EML, mainly over northern MN. Large to extreme buoyancy will develop, centered on eastern SD into western MN, with MLCAPE in excess of 4000 J/kg probable. Isolated late-afternoon to early-evening storm development will be possible near the cold front over eastern ND into west-central/northwest MN. Guidance differs greatly on whether this will occur or not given the stout capping to the southeast. A more probable scenario is for elevated convection to develop during the evening into the overnight as a low-level jet intensifies from the Mid-MO Valley towards Lake Superior. Guidance also differs on the evolution of the surface warm front into Monday evening/night with the 12Z NAM holding farther south and more pronounced with the baroclinic zone across central MN. Most other guidance advances the warm front deeper into northern MN. Given these spatial concerns along with the relatively weak forcing for ascent near/just after peak heating amid pronounced capping over the open warm sector, confidence is low in the most likely scenario of convective evolution. Isolated, very large hail will be possible given plentiful elevated MUCAPE and strengthening effective bulk shear. The 12Z HRW-ARW depicts a more ominous scenario with surface-based development over the Upper Red River Valley growing upscale into an intense, bowing MCS through central portions of MN/WI. This includes a signal for extreme rear-inflow jet development to around 95 kts at the mature stage over west-central WI. Other guidance suggests a later MCS may develop out of the elevated convection in north parts of MN/WI, and still other guidance suggests little, if any MCS development will occur. The decision has been made to defer on a categorical upgrade and await potentially more consistent guidance in later outlook cycles. ...Black Hills vicinity into parts of NE and western IA... The southern portion of the weak cold front should slow and stall near the SD/NE border area by early evening Monday. Strong heating in the vicinity of the boundary will support isolated to widely scattered high-based thunderstorm development. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support at least isolated severe gusts. The strongest updrafts may also be capable of producing some hail. ...Coastal Carolinas... A cold front is forecast to move across the coastal Carolinas vicinity, with scattered thunderstorm development expected during the afternoon. Moderate to locally strong prefrontal buoyancy (with MLCAPE of near/above 2000 J/kg) and effective shear generally around 25-30 kt will support potential for a few stronger multicells and perhaps a marginal supercell or two, with an attendant threat of locally damaging winds and hail. ..Grams.. 06/23/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, mainly from late afternoon Monday into Monday night. A low-probability scenario of a severe MCS producing destructive wind gusts is apparent, centered on central parts of Minnesota into Wisconsin. ...Upper Midwest... Confidence in tomorrow's severe evolution is low. A wide range in potential outcomes from a sporadic primarily elevated large hail threat to a derecho scenario are plausible. Primary change with this outlook is to add a significant severe wind area for the conditional potential of destructive wind gusts from an intense MCS. A shortwave trough should amplify somewhat over the southern Prairie Provinces, mainly during the latter portion of the period. This will induce weak mid-level height falls by Monday evening/night across northern portions of the Upper Midwest. Primary surface cyclone will similarly track east from southeast SK to far northwest ON. A north/south-oriented cold front attendant to this cyclone should push east across the northern Great Plains, with the trailing portion slowing and eventually stalling near the SD/NE border area. A very stout EML characterized by 700-mb temperatures of 14-16 C will inhibit surface-based warm sector development through much of the day, with remnant elevated convection from late D1 over ND potentially persisting on an isolated basis along the periphery of the EML, mainly over northern MN. Large to extreme buoyancy will develop, centered on eastern SD into western MN, with MLCAPE in excess of 4000 J/kg probable. Isolated late-afternoon to early-evening storm development will be possible near the cold front over eastern ND into west-central/northwest MN. Guidance differs greatly on whether this will occur or not given the stout capping to the southeast. A more probable scenario is for elevated convection to develop during the evening into the overnight as a low-level jet intensifies from the Mid-MO Valley towards Lake Superior. Guidance also differs on the evolution of the surface warm front into Monday evening/night with the 12Z NAM holding farther south and more pronounced with the baroclinic zone across central MN. Most other guidance advances the warm front deeper into northern MN. Given these spatial concerns along with the relatively weak forcing for ascent near/just after peak heating amid pronounced capping over the open warm sector, confidence is low in the most likely scenario of convective evolution. Isolated, very large hail will be possible given plentiful elevated MUCAPE and strengthening effective bulk shear. The 12Z HRW-ARW depicts a more ominous scenario with surface-based development over the Upper Red River Valley growing upscale into an intense, bowing MCS through central portions of MN/WI. This includes a signal for extreme rear-inflow jet development to around 95 kts at the mature stage over west-central WI. Other guidance suggests a later MCS may develop out of the elevated convection in north parts of MN/WI, and still other guidance suggests little, if any MCS development will occur. The decision has been made to defer on a categorical upgrade and await potentially more consistent guidance in later outlook cycles. ...Black Hills vicinity into parts of NE and western IA... The southern portion of the weak cold front should slow and stall near the SD/NE border area by early evening Monday. Strong heating in the vicinity of the boundary will support isolated to widely scattered high-based thunderstorm development. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support at least isolated severe gusts. The strongest updrafts may also be capable of producing some hail. ...Coastal Carolinas... A cold front is forecast to move across the coastal Carolinas vicinity, with scattered thunderstorm development expected during the afternoon. Moderate to locally strong prefrontal buoyancy (with MLCAPE of near/above 2000 J/kg) and effective shear generally around 25-30 kt will support potential for a few stronger multicells and perhaps a marginal supercell or two, with an attendant threat of locally damaging winds and hail. ..Grams.. 06/23/2024 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Sun Jun 23 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE UPPER MIDWEST... ...SUMMARY... Scattered severe thunderstorms will be possible over parts of the Upper Midwest, mainly from late afternoon Monday into Monday night. A low-probability scenario of a severe MCS producing destructive wind gusts is apparent, centered on central parts of Minnesota into Wisconsin. ...Upper Midwest... Confidence in tomorrow's severe evolution is low. A wide range in potential outcomes from a sporadic primarily elevated large hail threat to a derecho scenario are plausible. Primary change with this outlook is to add a significant severe wind area for the conditional potential of destructive wind gusts from an intense MCS. A shortwave trough should amplify somewhat over the southern Prairie Provinces, mainly during the latter portion of the period. This will induce weak mid-level height falls by Monday evening/night across northern portions of the Upper Midwest. Primary surface cyclone will similarly track east from southeast SK to far northwest ON. A north/south-oriented cold front attendant to this cyclone should push east across the northern Great Plains, with the trailing portion slowing and eventually stalling near the SD/NE border area. A very stout EML characterized by 700-mb temperatures of 14-16 C will inhibit surface-based warm sector development through much of the day, with remnant elevated convection from late D1 over ND potentially persisting on an isolated basis along the periphery of the EML, mainly over northern MN. Large to extreme buoyancy will develop, centered on eastern SD into western MN, with MLCAPE in excess of 4000 J/kg probable. Isolated late-afternoon to early-evening storm development will be possible near the cold front over eastern ND into west-central/northwest MN. Guidance differs greatly on whether this will occur or not given the stout capping to the southeast. A more probable scenario is for elevated convection to develop during the evening into the overnight as a low-level jet intensifies from the Mid-MO Valley towards Lake Superior. Guidance also differs on the evolution of the surface warm front into Monday evening/night with the 12Z NAM holding farther south and more pronounced with the baroclinic zone across central MN. Most other guidance advances the warm front deeper into northern MN. Given these spatial concerns along with the relatively weak forcing for ascent near/just after peak heating amid pronounced capping over the open warm sector, confidence is low in the most likely scenario of convective evolution. Isolated, very large hail will be possible given plentiful elevated MUCAPE and strengthening effective bulk shear. The 12Z HRW-ARW depicts a more ominous scenario with surface-based development over the Upper Red River Valley growing upscale into an intense, bowing MCS through central portions of MN/WI. This includes a signal for extreme rear-inflow jet development to around 95 kts at the mature stage over west-central WI. Other guidance suggests a later MCS may develop out of the elevated convection in north parts of MN/WI, and still other guidance suggests little, if any MCS development will occur. The decision has been made to defer on a categorical upgrade and await potentially more consistent guidance in later outlook cycles. ...Black Hills vicinity into parts of NE and western IA... The southern portion of the weak cold front should slow and stall near the SD/NE border area by early evening Monday. Strong heating in the vicinity of the boundary will support isolated to widely scattered high-based thunderstorm development. With generally weak mid-level flow across the region, storms may quickly become outflow dominant, but steep tropospheric lapse rates will support at least isolated severe gusts. The strongest updrafts may also be capable of producing some hail. ...Coastal Carolinas... A cold front is forecast to move across the coastal Carolinas vicinity, with scattered thunderstorm development expected during the afternoon. Moderate to locally strong prefrontal buoyancy (with MLCAPE of near/above 2000 J/kg) and effective shear generally around 25-30 kt will support potential for a few stronger multicells and perhaps a marginal supercell or two, with an attendant threat of locally damaging winds and hail. ..Grams.. 06/23/2024 Read more