Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1153 AM CDT Tue May 07 2024 Valid 071700Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF CENTRAL/EASTERN NEW MEXICO INTO SOUTHEAST COLORADO... The Elevated area was extended westward into the White Mountains in northern Arizona. Latest fuel guidance indicates ERCs in this region are approaching the 75 percentile. Otherwise, no changes were made to the Critical area. See previous discussion for more information. ..Thornton.. 05/07/2024 .PREV DISCUSSION... /ISSUED 1256 AM CDT Tue May 07 2024/ ...Synopsis... A broad upper cyclone will be situated in the northern Plains today. Strong mid-level winds will remain across the southern Rockies. A surface cyclone will deepen in the southern High Plains. ...Southwest... Strong surface winds will develop in response to the upper trough and surface cyclone to the east. Winds of 15-25 mph appear probable with locally higher speeds in terrain-favored areas. RH will fall to 10-15% though single digits could occur locally. Fuels in the area will continue to support an elevated to critical fire weather threat. ...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 1153 AM CDT Tue May 07 2024 Valid 071700Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF CENTRAL/EASTERN NEW MEXICO INTO SOUTHEAST COLORADO... The Elevated area was extended westward into the White Mountains in northern Arizona. Latest fuel guidance indicates ERCs in this region are approaching the 75 percentile. Otherwise, no changes were made to the Critical area. See previous discussion for more information. ..Thornton.. 05/07/2024 .PREV DISCUSSION... /ISSUED 1256 AM CDT Tue May 07 2024/ ...Synopsis... A broad upper cyclone will be situated in the northern Plains today. Strong mid-level winds will remain across the southern Rockies. A surface cyclone will deepen in the southern High Plains. ...Southwest... Strong surface winds will develop in response to the upper trough and surface cyclone to the east. Winds of 15-25 mph appear probable with locally higher speeds in terrain-favored areas. RH will fall to 10-15% though single digits could occur locally. Fuels in the area will continue to support an elevated to critical fire weather threat. ...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 1153 AM CDT Tue May 07 2024 Valid 071700Z - 081200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF CENTRAL/EASTERN NEW MEXICO INTO SOUTHEAST COLORADO... The Elevated area was extended westward into the White Mountains in northern Arizona. Latest fuel guidance indicates ERCs in this region are approaching the 75 percentile. Otherwise, no changes were made to the Critical area. See previous discussion for more information. ..Thornton.. 05/07/2024 .PREV DISCUSSION... /ISSUED 1256 AM CDT Tue May 07 2024/ ...Synopsis... A broad upper cyclone will be situated in the northern Plains today. Strong mid-level winds will remain across the southern Rockies. A surface cyclone will deepen in the southern High Plains. ...Southwest... Strong surface winds will develop in response to the upper trough and surface cyclone to the east. Winds of 15-25 mph appear probable with locally higher speeds in terrain-favored areas. RH will fall to 10-15% though single digits could occur locally. Fuels in the area will continue to support an elevated to critical fire weather threat. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No Mesoscale Discussions are in effect as of Tue May 7 16:56:01 UTC 2024.

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1136 AM CDT Tue May 07 2024 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley this afternoon and evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. ..Smith/Jewell.. 05/07/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1136 AM CDT Tue May 07 2024 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley this afternoon and evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. ..Smith/Jewell.. 05/07/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1136 AM CDT Tue May 07 2024 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley this afternoon and evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. ..Smith/Jewell.. 05/07/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1136 AM CDT Tue May 07 2024 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley this afternoon and evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. ..Smith/Jewell.. 05/07/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1136 AM CDT Tue May 07 2024 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley this afternoon and evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. ..Smith/Jewell.. 05/07/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1136 AM CDT Tue May 07 2024 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley this afternoon and evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. ..Smith/Jewell.. 05/07/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1136 AM CDT Tue May 07 2024 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley this afternoon and evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. ..Smith/Jewell.. 05/07/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1136 AM CDT Tue May 07 2024 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley this afternoon and evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. ..Smith/Jewell.. 05/07/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1136 AM CDT Tue May 07 2024 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley this afternoon and evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. ..Smith/Jewell.. 05/07/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1136 AM CDT Tue May 07 2024 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley this afternoon and evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. ..Smith/Jewell.. 05/07/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1136 AM CDT Tue May 07 2024 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley this afternoon and evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. ..Smith/Jewell.. 05/07/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1136 AM CDT Tue May 07 2024 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley this afternoon and evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. ..Smith/Jewell.. 05/07/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1136 AM CDT Tue May 07 2024 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley this afternoon and evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. ..Smith/Jewell.. 05/07/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1136 AM CDT Tue May 07 2024 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley this afternoon and evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. ..Smith/Jewell.. 05/07/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1136 AM CDT Tue May 07 2024 Valid 071630Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR INDIANA...WESTERN AND CENTRAL OHIO...AND NORTHERN KENTUCKY... ...SUMMARY... Scattered severe thunderstorms are expected across the southern Great Lakes and Ohio Valley this afternoon and evening. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...Southern Great Lakes/Ohio Valley and vicinity... Considerable uncertainty remains for this forecast due largely in part to an ongoing broken squall line moving east across KY/IN/Lake Michigan and the related influences for airmass destabilization in its wake. However, clearing skies in the MCS' wake will result in a seemingly sufficient period of heating during the afternoon. Water-vapor imagery shows the deep-layer cyclone centered over the northern Great Plains. A mid-level speed max rotating through the base of the larger-scale trough will move from the mid MS Valley late this morning into the southern Great Lakes by early evening. Rapid strengthening of southwesterly 500-mb flow is forecast over northern IL into the northern half of IN through the mid-late afternoon. As an effective warm frontal zone becomes draped across the southern Great Lakes/OH Valley regions, curved low-level hodographs beneath a lengthening of the mid and upper part of the hodograph will support a supercell risk. It seems most probable based on morning model guidance that storms will initially develop across central/northern IL and move northeast into northern IN. Isolated to scattered storms are forecast to eventually develop this afternoon across parts of the OH Valley in association with warm/moist-air advection---although considerable uncertainty remains regarding this scenario. The stronger storms (i.e., supercells) will be potentially capable of a large to very large hail threat, in addition to several tornadoes (perhaps a few which may be strong). ...Arklatex to north-central and south-central TX... Not much change in the forecast thinking across the Mid South southwestward into parts of TX. Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm-advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ...Southeast KS late tonight... A strengthening LLJ and associated warm-air advection will be focused over the northeast OK/southeast KS region late tonight. Forecast soundings show large MUCAPE amidst strong deep-layer shear. Large hail may accompany a stronger storm or two that manages to develop/become sustained during the 08-12z period. ..Smith/Jewell.. 05/07/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0749 AM CDT Tue May 07 2024 Valid 071300Z - 081200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PARTS OF INDIANA...OHIO AND NORTHERN/CENTRAL KENTUCKY... ...SUMMARY... Scattered severe thunderstorms are expected across the Ohio Valley today. A few tornadoes (some strong), large to very large hail, and severe/damaging winds all appear possible. ...Synopsis... A mid/upper cyclone, now occluded at low levels, will meander over the northern Great Plains and fill gradually through the period. As that occurs, a shortwave trough in its southeastern quadrant over IA will eject northward across MN and weaken. A trailing shortwave trough -- apparent in moisture-channel imagery over portions of KS -- should merge with the trailing portion of the IA perturbation then pivot across northern MO, southern IA and the DBQ vicinity, reaching northern IL and Lake Michigan by 00Z. That trough then should turn eastward through a larger-scale ridge and cross Lower MI overnight. South of those troughs, a broad fetch of southwest to west-southwest flow aloft -- with minor and mainly convectively influenced perturbations -- should extend from the southern Plains to the Ohio Valley. At the surface, 11Z analysis depicted a surface low near MBG, with occluded front southeastward to southern IA, becoming a cold front across western MO, eastern/southern OK, to the TX Permian Basin and southeastern NM. A warm front was drawn across central IL and southern IN, with secondary warm front/frontogenesis to its north over central IN and southern OH. The western part of both warm fronts should consolidate through the day, amid a broader plume of warm advection over the Ohio Valley. By 00Z, the cold front should reach central IN, southern IL, the eastern Ozarks, southeastern OK, north-central and central TX, with the TX part becoming stationary. The front will move northward overnight and become diffuse, amidst a broad fetch of southerly flow responding to surface cyclogenesis shifting from southeastern KS to northern OK. ...Ohio Valley and vicinity... A complex and multi-episode severe threat exists today over the region. First, an ongoing band of strong/isolated severe thunderstorms was apparent across portions of IL, southwestward over southeastern MO and northeastern AR. Though favorable moisture and buoyancy exists in the foregoing warm sector (along and south of the warm front), height falls aloft and deep-layer lift will be greatest over the middle and northern parts, near and just south of the warm front and mainly north of the Ohio Rover. What does not overtake too much of the warm frontal zone and dissipate in the next few hours may reintensify as it encounters diurnally destabilizing low levels, related both to low-level theta-e advection and cloudiness- restrained surface diabatic heating. At least isolated severe gusts would be the main concern with any such convection, which should diminish as it moves over/past eastern IN/western OH while outrunning already marginally favorable inflow-layer buoyancy. The more-substantial severe concern exists for thunderstorms forming this afternoon along/ahead of the cold front, then impinging on a corridor of favorable heating and warm/moist advection behind the morning activity. Surface dewpoints should recover into the mid- upper 60s F, beneath a plume of steepening midlevel lapse rates that is part of a remnant, somewhat modified EML spreading over the area of low-level destabilization. Superposition of these processes should yield peak MLCAPE in the 2000-3000 J/kg range over the "enhanced" area, narrowing and weakening northward into Lower MI. Favorable wind profiles are forecast, with effective-shear magnitudes in the 55-65-kt range and large-enough hodographs to support 200-400 J/kg effective SRH. To the extent an supercells that develop can remain relatively discrete, hodographs in the lowest couple km appear favorable for tornadoes (some possibly strong). Damaging, large to very large hail also is a concern with any such supercells. Buoyancy should be even greater with southwestward extent into steeper midlevel lapse rates and greater boundary-layer moisture of the Mid-South, and also southward over the Tennessee Valley into AL, but with weaker overall forcing and/or vertical shear otherwise, coverage and organization of strong-severe convection are likely to be less. ...Arklatex to north-central and south-central TX... Isolated severe thunderstorms are possible during mid/late afternoon. Damaging gusts and large hail would be the main concerns. The threat over the area is conditional -- more due to weak lift than thermodynamic considerations. Surface dewpoints commonly in the 70s F will underlie a deep troposphere and enough middle-level lapse rates for MLCAPE in the 3500-4500 J/kg range. Weak low-level winds will constrain hodograph size and boundary- layer shear. However, enough mid/upper flow remains to support around 45-55 kt effective-shear magnitudes, yielding a conditional supercell environment. In the absence of meaningful large-scale support, and with shallower overall lift near the front/dryline, convective coverage over this region is more in question and likely isolated. Additional convection may form overnight in a warm- advection plume near and southeast of the front, across parts of the Mid-South to Arklatex regions. Marginal hail and isolated damaging gusts would be the main concerns. ..Edwards/Broyles.. 05/07/2024 Read more