Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1142 AM CDT Sun Apr 14 2024 Valid 141700Z - 151200Z No changes to the ongoing forecast. ..Wendt.. 04/14/2024 .PREV DISCUSSION... /ISSUED 0202 AM CDT Sun Apr 14 2024/ ...Synopsis... A broad upper-level cyclone is forecast to intensify and slowly drift southeastward into the Great Basin Today. To the south, strong mid-level flow from an enhanced subtropical jet will move into the Desert Southwest. As strong wind fields overspread the western CONUS, lee cyclogenesis is forecast to begin over the central Rockies. Strong surface wind fields over the Intermountain west will slowly move into the southern High Plains behind the lee trough. Low humidity and increasing winds will likely support elevated fire-weather potential over parts of the southern High Plains. ...Southern High Plains... As the upper low consolidates over the western CONUS, strong flow aloft will begin to overspread the southern Rockies and High Plains. The lee trough is forecast to slowly deepen into a surface low over northeastern CO by late in the afternoon. With the deepening lee trough and increasing flow aloft, gusty southwest surface winds of 15-20 mph are likely over parts of southeastern NM into west/Southwest TX. Warm temperatures and deep mixing behind the lee trough should also encourage dry surface conditions with diurnal RH minimums below 15%. With area fuels receptive to fire spread a few hours of elevated fire-weather conditions are likely. More localized fire-weather conditions are possible farther north into southern CO. However, flow aloft will be somewhat delayed here keeping gusty winds more localized. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1142 AM CDT Sun Apr 14 2024 Valid 141700Z - 151200Z No changes to the ongoing forecast. ..Wendt.. 04/14/2024 .PREV DISCUSSION... /ISSUED 0202 AM CDT Sun Apr 14 2024/ ...Synopsis... A broad upper-level cyclone is forecast to intensify and slowly drift southeastward into the Great Basin Today. To the south, strong mid-level flow from an enhanced subtropical jet will move into the Desert Southwest. As strong wind fields overspread the western CONUS, lee cyclogenesis is forecast to begin over the central Rockies. Strong surface wind fields over the Intermountain west will slowly move into the southern High Plains behind the lee trough. Low humidity and increasing winds will likely support elevated fire-weather potential over parts of the southern High Plains. ...Southern High Plains... As the upper low consolidates over the western CONUS, strong flow aloft will begin to overspread the southern Rockies and High Plains. The lee trough is forecast to slowly deepen into a surface low over northeastern CO by late in the afternoon. With the deepening lee trough and increasing flow aloft, gusty southwest surface winds of 15-20 mph are likely over parts of southeastern NM into west/Southwest TX. Warm temperatures and deep mixing behind the lee trough should also encourage dry surface conditions with diurnal RH minimums below 15%. With area fuels receptive to fire spread a few hours of elevated fire-weather conditions are likely. More localized fire-weather conditions are possible farther north into southern CO. However, flow aloft will be somewhat delayed here keeping gusty winds more localized. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1142 AM CDT Sun Apr 14 2024 Valid 141700Z - 151200Z No changes to the ongoing forecast. ..Wendt.. 04/14/2024 .PREV DISCUSSION... /ISSUED 0202 AM CDT Sun Apr 14 2024/ ...Synopsis... A broad upper-level cyclone is forecast to intensify and slowly drift southeastward into the Great Basin Today. To the south, strong mid-level flow from an enhanced subtropical jet will move into the Desert Southwest. As strong wind fields overspread the western CONUS, lee cyclogenesis is forecast to begin over the central Rockies. Strong surface wind fields over the Intermountain west will slowly move into the southern High Plains behind the lee trough. Low humidity and increasing winds will likely support elevated fire-weather potential over parts of the southern High Plains. ...Southern High Plains... As the upper low consolidates over the western CONUS, strong flow aloft will begin to overspread the southern Rockies and High Plains. The lee trough is forecast to slowly deepen into a surface low over northeastern CO by late in the afternoon. With the deepening lee trough and increasing flow aloft, gusty southwest surface winds of 15-20 mph are likely over parts of southeastern NM into west/Southwest TX. Warm temperatures and deep mixing behind the lee trough should also encourage dry surface conditions with diurnal RH minimums below 15%. With area fuels receptive to fire spread a few hours of elevated fire-weather conditions are likely. More localized fire-weather conditions are possible farther north into southern CO. However, flow aloft will be somewhat delayed here keeping gusty winds more localized. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1142 AM CDT Sun Apr 14 2024 Valid 141700Z - 151200Z No changes to the ongoing forecast. ..Wendt.. 04/14/2024 .PREV DISCUSSION... /ISSUED 0202 AM CDT Sun Apr 14 2024/ ...Synopsis... A broad upper-level cyclone is forecast to intensify and slowly drift southeastward into the Great Basin Today. To the south, strong mid-level flow from an enhanced subtropical jet will move into the Desert Southwest. As strong wind fields overspread the western CONUS, lee cyclogenesis is forecast to begin over the central Rockies. Strong surface wind fields over the Intermountain west will slowly move into the southern High Plains behind the lee trough. Low humidity and increasing winds will likely support elevated fire-weather potential over parts of the southern High Plains. ...Southern High Plains... As the upper low consolidates over the western CONUS, strong flow aloft will begin to overspread the southern Rockies and High Plains. The lee trough is forecast to slowly deepen into a surface low over northeastern CO by late in the afternoon. With the deepening lee trough and increasing flow aloft, gusty southwest surface winds of 15-20 mph are likely over parts of southeastern NM into west/Southwest TX. Warm temperatures and deep mixing behind the lee trough should also encourage dry surface conditions with diurnal RH minimums below 15%. With area fuels receptive to fire spread a few hours of elevated fire-weather conditions are likely. More localized fire-weather conditions are possible farther north into southern CO. However, flow aloft will be somewhat delayed here keeping gusty winds more localized. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 14 2024 Valid 141630Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR EASTERN OHIO INTO WESTERN AND NORTHERN PENNSYLVANIA... ...SUMMARY... Severe thunderstorms should develop late this afternoon in a narrow corridor across the upper Ohio Valley into Pennsylvania and vicinity. Damaging winds should be the main threat. Severe hail and perhaps a couple of tornadoes also appear possible as this activity spreads southeastward into this evening. ...Ohio Valley into the Mid-Atlantic and Northeast... Surface analysis late this morning shows the northeastern rim of 50s dewpoints over northern KY/southwest OH being quickly advected east-northeastward on a 40-kt west-southwesterly LLJ. The Upper OH Valley is located immediately downstream of a mid-level vorticity maximum over Lake Michigan. This disturbance will continue to move into the base of the larger-scale eastern Canada/Northeast U.S. mid-level trough. An accompanying weak low will migrate eastward from the Great Lakes across NY, while a weak cold front extends to the west-southwest and is forecast to push east-southeast across the Lower Great Lakes before weakening and becoming draped across the Upper OH Valley late. Continued low-level moist advection will likely result in upper 40s to low 50s surface dewpoints within a narrow corridor along and south of a cold front from OH into PA and southern NY. Steep 700-500 mb lapse rates due in part to cool mid levels (i.e., -18 deg C at 500 mb) and heating will yield 500-1250 J/kg MLCAPE by mid-late afternoon. Surface-based thunderstorm initiation across this region will likely be delayed until 20-21Z or later, as lingering MLCIN and a cap gradually erodes. Initial development should be focused along the front across parts of eastern OH into western/central PA, with additional development eventually occurring into eastern PA and parts of southern NY. Given strong deep-layer shear and favorable lapse rates, large hail may occur with the more robust cores initially. Some threat for a couple of tornadoes may also exist with quasi-discrete supercells early in the thunderstorm life cycle, as sufficient low-level shear will be present for updraft rotation. But, with the surface front aligned mostly parallel to the enhanced westerly low/mid-level flow, upscale growth into small bowing clusters will likely occur as additional storms develop and cold pools merge as the band of storms moves southeastward. Scattered damaging winds will then likely become the main threat with these clusters through the early evening. As instability wanes after sunset, the wind threat will gradually decrease with southward/eastward extent. ..Smith/Bentley.. 04/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 14 2024 Valid 141630Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR EASTERN OHIO INTO WESTERN AND NORTHERN PENNSYLVANIA... ...SUMMARY... Severe thunderstorms should develop late this afternoon in a narrow corridor across the upper Ohio Valley into Pennsylvania and vicinity. Damaging winds should be the main threat. Severe hail and perhaps a couple of tornadoes also appear possible as this activity spreads southeastward into this evening. ...Ohio Valley into the Mid-Atlantic and Northeast... Surface analysis late this morning shows the northeastern rim of 50s dewpoints over northern KY/southwest OH being quickly advected east-northeastward on a 40-kt west-southwesterly LLJ. The Upper OH Valley is located immediately downstream of a mid-level vorticity maximum over Lake Michigan. This disturbance will continue to move into the base of the larger-scale eastern Canada/Northeast U.S. mid-level trough. An accompanying weak low will migrate eastward from the Great Lakes across NY, while a weak cold front extends to the west-southwest and is forecast to push east-southeast across the Lower Great Lakes before weakening and becoming draped across the Upper OH Valley late. Continued low-level moist advection will likely result in upper 40s to low 50s surface dewpoints within a narrow corridor along and south of a cold front from OH into PA and southern NY. Steep 700-500 mb lapse rates due in part to cool mid levels (i.e., -18 deg C at 500 mb) and heating will yield 500-1250 J/kg MLCAPE by mid-late afternoon. Surface-based thunderstorm initiation across this region will likely be delayed until 20-21Z or later, as lingering MLCIN and a cap gradually erodes. Initial development should be focused along the front across parts of eastern OH into western/central PA, with additional development eventually occurring into eastern PA and parts of southern NY. Given strong deep-layer shear and favorable lapse rates, large hail may occur with the more robust cores initially. Some threat for a couple of tornadoes may also exist with quasi-discrete supercells early in the thunderstorm life cycle, as sufficient low-level shear will be present for updraft rotation. But, with the surface front aligned mostly parallel to the enhanced westerly low/mid-level flow, upscale growth into small bowing clusters will likely occur as additional storms develop and cold pools merge as the band of storms moves southeastward. Scattered damaging winds will then likely become the main threat with these clusters through the early evening. As instability wanes after sunset, the wind threat will gradually decrease with southward/eastward extent. ..Smith/Bentley.. 04/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 14 2024 Valid 141630Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR EASTERN OHIO INTO WESTERN AND NORTHERN PENNSYLVANIA... ...SUMMARY... Severe thunderstorms should develop late this afternoon in a narrow corridor across the upper Ohio Valley into Pennsylvania and vicinity. Damaging winds should be the main threat. Severe hail and perhaps a couple of tornadoes also appear possible as this activity spreads southeastward into this evening. ...Ohio Valley into the Mid-Atlantic and Northeast... Surface analysis late this morning shows the northeastern rim of 50s dewpoints over northern KY/southwest OH being quickly advected east-northeastward on a 40-kt west-southwesterly LLJ. The Upper OH Valley is located immediately downstream of a mid-level vorticity maximum over Lake Michigan. This disturbance will continue to move into the base of the larger-scale eastern Canada/Northeast U.S. mid-level trough. An accompanying weak low will migrate eastward from the Great Lakes across NY, while a weak cold front extends to the west-southwest and is forecast to push east-southeast across the Lower Great Lakes before weakening and becoming draped across the Upper OH Valley late. Continued low-level moist advection will likely result in upper 40s to low 50s surface dewpoints within a narrow corridor along and south of a cold front from OH into PA and southern NY. Steep 700-500 mb lapse rates due in part to cool mid levels (i.e., -18 deg C at 500 mb) and heating will yield 500-1250 J/kg MLCAPE by mid-late afternoon. Surface-based thunderstorm initiation across this region will likely be delayed until 20-21Z or later, as lingering MLCIN and a cap gradually erodes. Initial development should be focused along the front across parts of eastern OH into western/central PA, with additional development eventually occurring into eastern PA and parts of southern NY. Given strong deep-layer shear and favorable lapse rates, large hail may occur with the more robust cores initially. Some threat for a couple of tornadoes may also exist with quasi-discrete supercells early in the thunderstorm life cycle, as sufficient low-level shear will be present for updraft rotation. But, with the surface front aligned mostly parallel to the enhanced westerly low/mid-level flow, upscale growth into small bowing clusters will likely occur as additional storms develop and cold pools merge as the band of storms moves southeastward. Scattered damaging winds will then likely become the main threat with these clusters through the early evening. As instability wanes after sunset, the wind threat will gradually decrease with southward/eastward extent. ..Smith/Bentley.. 04/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 14 2024 Valid 141630Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR EASTERN OHIO INTO WESTERN AND NORTHERN PENNSYLVANIA... ...SUMMARY... Severe thunderstorms should develop late this afternoon in a narrow corridor across the upper Ohio Valley into Pennsylvania and vicinity. Damaging winds should be the main threat. Severe hail and perhaps a couple of tornadoes also appear possible as this activity spreads southeastward into this evening. ...Ohio Valley into the Mid-Atlantic and Northeast... Surface analysis late this morning shows the northeastern rim of 50s dewpoints over northern KY/southwest OH being quickly advected east-northeastward on a 40-kt west-southwesterly LLJ. The Upper OH Valley is located immediately downstream of a mid-level vorticity maximum over Lake Michigan. This disturbance will continue to move into the base of the larger-scale eastern Canada/Northeast U.S. mid-level trough. An accompanying weak low will migrate eastward from the Great Lakes across NY, while a weak cold front extends to the west-southwest and is forecast to push east-southeast across the Lower Great Lakes before weakening and becoming draped across the Upper OH Valley late. Continued low-level moist advection will likely result in upper 40s to low 50s surface dewpoints within a narrow corridor along and south of a cold front from OH into PA and southern NY. Steep 700-500 mb lapse rates due in part to cool mid levels (i.e., -18 deg C at 500 mb) and heating will yield 500-1250 J/kg MLCAPE by mid-late afternoon. Surface-based thunderstorm initiation across this region will likely be delayed until 20-21Z or later, as lingering MLCIN and a cap gradually erodes. Initial development should be focused along the front across parts of eastern OH into western/central PA, with additional development eventually occurring into eastern PA and parts of southern NY. Given strong deep-layer shear and favorable lapse rates, large hail may occur with the more robust cores initially. Some threat for a couple of tornadoes may also exist with quasi-discrete supercells early in the thunderstorm life cycle, as sufficient low-level shear will be present for updraft rotation. But, with the surface front aligned mostly parallel to the enhanced westerly low/mid-level flow, upscale growth into small bowing clusters will likely occur as additional storms develop and cold pools merge as the band of storms moves southeastward. Scattered damaging winds will then likely become the main threat with these clusters through the early evening. As instability wanes after sunset, the wind threat will gradually decrease with southward/eastward extent. ..Smith/Bentley.. 04/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 14 2024 Valid 141630Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR EASTERN OHIO INTO WESTERN AND NORTHERN PENNSYLVANIA... ...SUMMARY... Severe thunderstorms should develop late this afternoon in a narrow corridor across the upper Ohio Valley into Pennsylvania and vicinity. Damaging winds should be the main threat. Severe hail and perhaps a couple of tornadoes also appear possible as this activity spreads southeastward into this evening. ...Ohio Valley into the Mid-Atlantic and Northeast... Surface analysis late this morning shows the northeastern rim of 50s dewpoints over northern KY/southwest OH being quickly advected east-northeastward on a 40-kt west-southwesterly LLJ. The Upper OH Valley is located immediately downstream of a mid-level vorticity maximum over Lake Michigan. This disturbance will continue to move into the base of the larger-scale eastern Canada/Northeast U.S. mid-level trough. An accompanying weak low will migrate eastward from the Great Lakes across NY, while a weak cold front extends to the west-southwest and is forecast to push east-southeast across the Lower Great Lakes before weakening and becoming draped across the Upper OH Valley late. Continued low-level moist advection will likely result in upper 40s to low 50s surface dewpoints within a narrow corridor along and south of a cold front from OH into PA and southern NY. Steep 700-500 mb lapse rates due in part to cool mid levels (i.e., -18 deg C at 500 mb) and heating will yield 500-1250 J/kg MLCAPE by mid-late afternoon. Surface-based thunderstorm initiation across this region will likely be delayed until 20-21Z or later, as lingering MLCIN and a cap gradually erodes. Initial development should be focused along the front across parts of eastern OH into western/central PA, with additional development eventually occurring into eastern PA and parts of southern NY. Given strong deep-layer shear and favorable lapse rates, large hail may occur with the more robust cores initially. Some threat for a couple of tornadoes may also exist with quasi-discrete supercells early in the thunderstorm life cycle, as sufficient low-level shear will be present for updraft rotation. But, with the surface front aligned mostly parallel to the enhanced westerly low/mid-level flow, upscale growth into small bowing clusters will likely occur as additional storms develop and cold pools merge as the band of storms moves southeastward. Scattered damaging winds will then likely become the main threat with these clusters through the early evening. As instability wanes after sunset, the wind threat will gradually decrease with southward/eastward extent. ..Smith/Bentley.. 04/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 14 2024 Valid 141630Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR EASTERN OHIO INTO WESTERN AND NORTHERN PENNSYLVANIA... ...SUMMARY... Severe thunderstorms should develop late this afternoon in a narrow corridor across the upper Ohio Valley into Pennsylvania and vicinity. Damaging winds should be the main threat. Severe hail and perhaps a couple of tornadoes also appear possible as this activity spreads southeastward into this evening. ...Ohio Valley into the Mid-Atlantic and Northeast... Surface analysis late this morning shows the northeastern rim of 50s dewpoints over northern KY/southwest OH being quickly advected east-northeastward on a 40-kt west-southwesterly LLJ. The Upper OH Valley is located immediately downstream of a mid-level vorticity maximum over Lake Michigan. This disturbance will continue to move into the base of the larger-scale eastern Canada/Northeast U.S. mid-level trough. An accompanying weak low will migrate eastward from the Great Lakes across NY, while a weak cold front extends to the west-southwest and is forecast to push east-southeast across the Lower Great Lakes before weakening and becoming draped across the Upper OH Valley late. Continued low-level moist advection will likely result in upper 40s to low 50s surface dewpoints within a narrow corridor along and south of a cold front from OH into PA and southern NY. Steep 700-500 mb lapse rates due in part to cool mid levels (i.e., -18 deg C at 500 mb) and heating will yield 500-1250 J/kg MLCAPE by mid-late afternoon. Surface-based thunderstorm initiation across this region will likely be delayed until 20-21Z or later, as lingering MLCIN and a cap gradually erodes. Initial development should be focused along the front across parts of eastern OH into western/central PA, with additional development eventually occurring into eastern PA and parts of southern NY. Given strong deep-layer shear and favorable lapse rates, large hail may occur with the more robust cores initially. Some threat for a couple of tornadoes may also exist with quasi-discrete supercells early in the thunderstorm life cycle, as sufficient low-level shear will be present for updraft rotation. But, with the surface front aligned mostly parallel to the enhanced westerly low/mid-level flow, upscale growth into small bowing clusters will likely occur as additional storms develop and cold pools merge as the band of storms moves southeastward. Scattered damaging winds will then likely become the main threat with these clusters through the early evening. As instability wanes after sunset, the wind threat will gradually decrease with southward/eastward extent. ..Smith/Bentley.. 04/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 14 2024 Valid 141630Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR EASTERN OHIO INTO WESTERN AND NORTHERN PENNSYLVANIA... ...SUMMARY... Severe thunderstorms should develop late this afternoon in a narrow corridor across the upper Ohio Valley into Pennsylvania and vicinity. Damaging winds should be the main threat. Severe hail and perhaps a couple of tornadoes also appear possible as this activity spreads southeastward into this evening. ...Ohio Valley into the Mid-Atlantic and Northeast... Surface analysis late this morning shows the northeastern rim of 50s dewpoints over northern KY/southwest OH being quickly advected east-northeastward on a 40-kt west-southwesterly LLJ. The Upper OH Valley is located immediately downstream of a mid-level vorticity maximum over Lake Michigan. This disturbance will continue to move into the base of the larger-scale eastern Canada/Northeast U.S. mid-level trough. An accompanying weak low will migrate eastward from the Great Lakes across NY, while a weak cold front extends to the west-southwest and is forecast to push east-southeast across the Lower Great Lakes before weakening and becoming draped across the Upper OH Valley late. Continued low-level moist advection will likely result in upper 40s to low 50s surface dewpoints within a narrow corridor along and south of a cold front from OH into PA and southern NY. Steep 700-500 mb lapse rates due in part to cool mid levels (i.e., -18 deg C at 500 mb) and heating will yield 500-1250 J/kg MLCAPE by mid-late afternoon. Surface-based thunderstorm initiation across this region will likely be delayed until 20-21Z or later, as lingering MLCIN and a cap gradually erodes. Initial development should be focused along the front across parts of eastern OH into western/central PA, with additional development eventually occurring into eastern PA and parts of southern NY. Given strong deep-layer shear and favorable lapse rates, large hail may occur with the more robust cores initially. Some threat for a couple of tornadoes may also exist with quasi-discrete supercells early in the thunderstorm life cycle, as sufficient low-level shear will be present for updraft rotation. But, with the surface front aligned mostly parallel to the enhanced westerly low/mid-level flow, upscale growth into small bowing clusters will likely occur as additional storms develop and cold pools merge as the band of storms moves southeastward. Scattered damaging winds will then likely become the main threat with these clusters through the early evening. As instability wanes after sunset, the wind threat will gradually decrease with southward/eastward extent. ..Smith/Bentley.. 04/14/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Sun Apr 14 2024 Valid 141630Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR EASTERN OHIO INTO WESTERN AND NORTHERN PENNSYLVANIA... ...SUMMARY... Severe thunderstorms should develop late this afternoon in a narrow corridor across the upper Ohio Valley into Pennsylvania and vicinity. Damaging winds should be the main threat. Severe hail and perhaps a couple of tornadoes also appear possible as this activity spreads southeastward into this evening. ...Ohio Valley into the Mid-Atlantic and Northeast... Surface analysis late this morning shows the northeastern rim of 50s dewpoints over northern KY/southwest OH being quickly advected east-northeastward on a 40-kt west-southwesterly LLJ. The Upper OH Valley is located immediately downstream of a mid-level vorticity maximum over Lake Michigan. This disturbance will continue to move into the base of the larger-scale eastern Canada/Northeast U.S. mid-level trough. An accompanying weak low will migrate eastward from the Great Lakes across NY, while a weak cold front extends to the west-southwest and is forecast to push east-southeast across the Lower Great Lakes before weakening and becoming draped across the Upper OH Valley late. Continued low-level moist advection will likely result in upper 40s to low 50s surface dewpoints within a narrow corridor along and south of a cold front from OH into PA and southern NY. Steep 700-500 mb lapse rates due in part to cool mid levels (i.e., -18 deg C at 500 mb) and heating will yield 500-1250 J/kg MLCAPE by mid-late afternoon. Surface-based thunderstorm initiation across this region will likely be delayed until 20-21Z or later, as lingering MLCIN and a cap gradually erodes. Initial development should be focused along the front across parts of eastern OH into western/central PA, with additional development eventually occurring into eastern PA and parts of southern NY. Given strong deep-layer shear and favorable lapse rates, large hail may occur with the more robust cores initially. Some threat for a couple of tornadoes may also exist with quasi-discrete supercells early in the thunderstorm life cycle, as sufficient low-level shear will be present for updraft rotation. But, with the surface front aligned mostly parallel to the enhanced westerly low/mid-level flow, upscale growth into small bowing clusters will likely occur as additional storms develop and cold pools merge as the band of storms moves southeastward. Scattered damaging winds will then likely become the main threat with these clusters through the early evening. As instability wanes after sunset, the wind threat will gradually decrease with southward/eastward extent. ..Smith/Bentley.. 04/14/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Sun Apr 14 2024 Valid 141300Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN OHIO INTO PENNSYLVANIA... ...SUMMARY... Severe thunderstorms should develop late this afternoon in a narrow corridor across the upper Ohio Valley into Pennsylvania and vicinity. Damaging winds should be the main threat. Severe hail and perhaps a couple of tornadoes also appear possible as this activity spreads slowly southward into this evening. ...Ohio Valley into the Mid-Atlantic and Northeast... Early morning surface observations show a dearth of low-level moisture from the upper OH Valley into the Mid-Atlantic, with surface dewpoints generally in the 30s. However, boundary-layer moisture will gradually increase through the day across these regions, as a weak surface low migrates eastward from the Great Lakes across NY. By late afternoon, generally upper 40s to low 50s surface dewpoints should become focused in a narrow corridor along and south of front from OH into PA and southern NY. With upper troughing persisting over eastern Canada and parts of the Northeast, generally westerly mid-level winds across the Midwest/OH Valley will aid in the eastward advection of an EML and associated steep mid-level lapse rates. Even though low-level moisture is expected to remain limited, these steepened lapse rates aloft, along with diurnal heating, should encourage the development of weak to locally moderate MLCAPE late this afternoon. Surface-based thunderstorm initiation across this region will likely be delayed until 20-21Z or later, as lingering MLCIN and a cap gradually erodes. Initial development should be focused along the front across parts of eastern OH into western/central PA, with additional development eventually occurring into eastern PA and parts of southern NY. Given strong deep-layer shear and favorable lapse rates, large hail may occur with the more robust cores initially. Some threat for a couple of tornadoes may also exist with semi-discrete convection, as sufficient low-level shear will be present for updraft rotation. But, with the surface front aligned mostly parallel to the enhanced westerly low/mid-level flow, upscale growth into small bowing clusters should quickly occur as convection spreads south-southeastward. Scattered damaging winds will likely become the main threat with these clusters through the early evening in a narrow spatial corridor extending from eastern OH into PA where instability and steep low/mid-level lapse rates should be maximized. The damaging wind threat will gradually decrease through the evening as instability lessens with southward/eastward extent. ..Gleason/Grams.. 04/14/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Sun Apr 14 2024 Valid 141300Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN OHIO INTO PENNSYLVANIA... ...SUMMARY... Severe thunderstorms should develop late this afternoon in a narrow corridor across the upper Ohio Valley into Pennsylvania and vicinity. Damaging winds should be the main threat. Severe hail and perhaps a couple of tornadoes also appear possible as this activity spreads slowly southward into this evening. ...Ohio Valley into the Mid-Atlantic and Northeast... Early morning surface observations show a dearth of low-level moisture from the upper OH Valley into the Mid-Atlantic, with surface dewpoints generally in the 30s. However, boundary-layer moisture will gradually increase through the day across these regions, as a weak surface low migrates eastward from the Great Lakes across NY. By late afternoon, generally upper 40s to low 50s surface dewpoints should become focused in a narrow corridor along and south of front from OH into PA and southern NY. With upper troughing persisting over eastern Canada and parts of the Northeast, generally westerly mid-level winds across the Midwest/OH Valley will aid in the eastward advection of an EML and associated steep mid-level lapse rates. Even though low-level moisture is expected to remain limited, these steepened lapse rates aloft, along with diurnal heating, should encourage the development of weak to locally moderate MLCAPE late this afternoon. Surface-based thunderstorm initiation across this region will likely be delayed until 20-21Z or later, as lingering MLCIN and a cap gradually erodes. Initial development should be focused along the front across parts of eastern OH into western/central PA, with additional development eventually occurring into eastern PA and parts of southern NY. Given strong deep-layer shear and favorable lapse rates, large hail may occur with the more robust cores initially. Some threat for a couple of tornadoes may also exist with semi-discrete convection, as sufficient low-level shear will be present for updraft rotation. But, with the surface front aligned mostly parallel to the enhanced westerly low/mid-level flow, upscale growth into small bowing clusters should quickly occur as convection spreads south-southeastward. Scattered damaging winds will likely become the main threat with these clusters through the early evening in a narrow spatial corridor extending from eastern OH into PA where instability and steep low/mid-level lapse rates should be maximized. The damaging wind threat will gradually decrease through the evening as instability lessens with southward/eastward extent. ..Gleason/Grams.. 04/14/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Sun Apr 14 2024 Valid 141300Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN OHIO INTO PENNSYLVANIA... ...SUMMARY... Severe thunderstorms should develop late this afternoon in a narrow corridor across the upper Ohio Valley into Pennsylvania and vicinity. Damaging winds should be the main threat. Severe hail and perhaps a couple of tornadoes also appear possible as this activity spreads slowly southward into this evening. ...Ohio Valley into the Mid-Atlantic and Northeast... Early morning surface observations show a dearth of low-level moisture from the upper OH Valley into the Mid-Atlantic, with surface dewpoints generally in the 30s. However, boundary-layer moisture will gradually increase through the day across these regions, as a weak surface low migrates eastward from the Great Lakes across NY. By late afternoon, generally upper 40s to low 50s surface dewpoints should become focused in a narrow corridor along and south of front from OH into PA and southern NY. With upper troughing persisting over eastern Canada and parts of the Northeast, generally westerly mid-level winds across the Midwest/OH Valley will aid in the eastward advection of an EML and associated steep mid-level lapse rates. Even though low-level moisture is expected to remain limited, these steepened lapse rates aloft, along with diurnal heating, should encourage the development of weak to locally moderate MLCAPE late this afternoon. Surface-based thunderstorm initiation across this region will likely be delayed until 20-21Z or later, as lingering MLCIN and a cap gradually erodes. Initial development should be focused along the front across parts of eastern OH into western/central PA, with additional development eventually occurring into eastern PA and parts of southern NY. Given strong deep-layer shear and favorable lapse rates, large hail may occur with the more robust cores initially. Some threat for a couple of tornadoes may also exist with semi-discrete convection, as sufficient low-level shear will be present for updraft rotation. But, with the surface front aligned mostly parallel to the enhanced westerly low/mid-level flow, upscale growth into small bowing clusters should quickly occur as convection spreads south-southeastward. Scattered damaging winds will likely become the main threat with these clusters through the early evening in a narrow spatial corridor extending from eastern OH into PA where instability and steep low/mid-level lapse rates should be maximized. The damaging wind threat will gradually decrease through the evening as instability lessens with southward/eastward extent. ..Gleason/Grams.. 04/14/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0746 AM CDT Sun Apr 14 2024 Valid 141300Z - 151200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EASTERN OHIO INTO PENNSYLVANIA... ...SUMMARY... Severe thunderstorms should develop late this afternoon in a narrow corridor across the upper Ohio Valley into Pennsylvania and vicinity. Damaging winds should be the main threat. Severe hail and perhaps a couple of tornadoes also appear possible as this activity spreads slowly southward into this evening. ...Ohio Valley into the Mid-Atlantic and Northeast... Early morning surface observations show a dearth of low-level moisture from the upper OH Valley into the Mid-Atlantic, with surface dewpoints generally in the 30s. However, boundary-layer moisture will gradually increase through the day across these regions, as a weak surface low migrates eastward from the Great Lakes across NY. By late afternoon, generally upper 40s to low 50s surface dewpoints should become focused in a narrow corridor along and south of front from OH into PA and southern NY. With upper troughing persisting over eastern Canada and parts of the Northeast, generally westerly mid-level winds across the Midwest/OH Valley will aid in the eastward advection of an EML and associated steep mid-level lapse rates. Even though low-level moisture is expected to remain limited, these steepened lapse rates aloft, along with diurnal heating, should encourage the development of weak to locally moderate MLCAPE late this afternoon. Surface-based thunderstorm initiation across this region will likely be delayed until 20-21Z or later, as lingering MLCIN and a cap gradually erodes. Initial development should be focused along the front across parts of eastern OH into western/central PA, with additional development eventually occurring into eastern PA and parts of southern NY. Given strong deep-layer shear and favorable lapse rates, large hail may occur with the more robust cores initially. Some threat for a couple of tornadoes may also exist with semi-discrete convection, as sufficient low-level shear will be present for updraft rotation. But, with the surface front aligned mostly parallel to the enhanced westerly low/mid-level flow, upscale growth into small bowing clusters should quickly occur as convection spreads south-southeastward. Scattered damaging winds will likely become the main threat with these clusters through the early evening in a narrow spatial corridor extending from eastern OH into PA where instability and steep low/mid-level lapse rates should be maximized. The damaging wind threat will gradually decrease through the evening as instability lessens with southward/eastward extent. ..Gleason/Grams.. 04/14/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0344 AM CDT Sun Apr 14 2024 Valid 171200Z - 221200Z ...DISCUSSION... ...D4/Wednesday... Guidance continues to suggest some severe threat will persist into Wednesday afternoon given the strength of low to mid-level flow before the Upper MS Valley surface cyclone further occludes and dampens over the western to central Great Lakes. The northeast lobe of the warm-moist sector emanating from the western Gulf should be more confined relative to D3/Tuesday. Thus, have only delineated a small 15 percent highlight where consensus of guidance suggests the best potential for daytime destabilization will overlap with the stronger low to deep-layer flow. Low severe probabilities are evident surrounding the highlight, both farther south-southwestward in the TN Valley/Mid-South and northeastward deeper into IN/OH. ...D5-8/Thursday-Sunday... A broad mid/upper trough is still advertised to become established over the Upper Midwest by about D5, with predictability waning in its evolution into next weekend. This should yield surface high pressure/ridging being periodically reinforced from at least the northern High Plains into the central Great Plains. Within the predominantly westerly mid-level flow regime across the rich warm-moist sector, an elevated mixed layer should support at least moderate buoyancy over parts of the TX/OK/AR/LA region. The quasi-stationary baroclinic zone should eventually be pushed south towards the northwest Gulf around next weekend. This overall setup may support daily bouts of low-probability severe. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0344 AM CDT Sun Apr 14 2024 Valid 171200Z - 221200Z ...DISCUSSION... ...D4/Wednesday... Guidance continues to suggest some severe threat will persist into Wednesday afternoon given the strength of low to mid-level flow before the Upper MS Valley surface cyclone further occludes and dampens over the western to central Great Lakes. The northeast lobe of the warm-moist sector emanating from the western Gulf should be more confined relative to D3/Tuesday. Thus, have only delineated a small 15 percent highlight where consensus of guidance suggests the best potential for daytime destabilization will overlap with the stronger low to deep-layer flow. Low severe probabilities are evident surrounding the highlight, both farther south-southwestward in the TN Valley/Mid-South and northeastward deeper into IN/OH. ...D5-8/Thursday-Sunday... A broad mid/upper trough is still advertised to become established over the Upper Midwest by about D5, with predictability waning in its evolution into next weekend. This should yield surface high pressure/ridging being periodically reinforced from at least the northern High Plains into the central Great Plains. Within the predominantly westerly mid-level flow regime across the rich warm-moist sector, an elevated mixed layer should support at least moderate buoyancy over parts of the TX/OK/AR/LA region. The quasi-stationary baroclinic zone should eventually be pushed south towards the northwest Gulf around next weekend. This overall setup may support daily bouts of low-probability severe. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0344 AM CDT Sun Apr 14 2024 Valid 171200Z - 221200Z ...DISCUSSION... ...D4/Wednesday... Guidance continues to suggest some severe threat will persist into Wednesday afternoon given the strength of low to mid-level flow before the Upper MS Valley surface cyclone further occludes and dampens over the western to central Great Lakes. The northeast lobe of the warm-moist sector emanating from the western Gulf should be more confined relative to D3/Tuesday. Thus, have only delineated a small 15 percent highlight where consensus of guidance suggests the best potential for daytime destabilization will overlap with the stronger low to deep-layer flow. Low severe probabilities are evident surrounding the highlight, both farther south-southwestward in the TN Valley/Mid-South and northeastward deeper into IN/OH. ...D5-8/Thursday-Sunday... A broad mid/upper trough is still advertised to become established over the Upper Midwest by about D5, with predictability waning in its evolution into next weekend. This should yield surface high pressure/ridging being periodically reinforced from at least the northern High Plains into the central Great Plains. Within the predominantly westerly mid-level flow regime across the rich warm-moist sector, an elevated mixed layer should support at least moderate buoyancy over parts of the TX/OK/AR/LA region. The quasi-stationary baroclinic zone should eventually be pushed south towards the northwest Gulf around next weekend. This overall setup may support daily bouts of low-probability severe. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0344 AM CDT Sun Apr 14 2024 Valid 171200Z - 221200Z ...DISCUSSION... ...D4/Wednesday... Guidance continues to suggest some severe threat will persist into Wednesday afternoon given the strength of low to mid-level flow before the Upper MS Valley surface cyclone further occludes and dampens over the western to central Great Lakes. The northeast lobe of the warm-moist sector emanating from the western Gulf should be more confined relative to D3/Tuesday. Thus, have only delineated a small 15 percent highlight where consensus of guidance suggests the best potential for daytime destabilization will overlap with the stronger low to deep-layer flow. Low severe probabilities are evident surrounding the highlight, both farther south-southwestward in the TN Valley/Mid-South and northeastward deeper into IN/OH. ...D5-8/Thursday-Sunday... A broad mid/upper trough is still advertised to become established over the Upper Midwest by about D5, with predictability waning in its evolution into next weekend. This should yield surface high pressure/ridging being periodically reinforced from at least the northern High Plains into the central Great Plains. Within the predominantly westerly mid-level flow regime across the rich warm-moist sector, an elevated mixed layer should support at least moderate buoyancy over parts of the TX/OK/AR/LA region. The quasi-stationary baroclinic zone should eventually be pushed south towards the northwest Gulf around next weekend. This overall setup may support daily bouts of low-probability severe. Read more