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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Tue Apr 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN SOUTHWARD INTO PARTS OF INDIANA/OHIO AND TOWARD THE OHIO RIVER... ...SUMMARY... Scattered severe thunderstorms are possible Wednesday afternoon and evening from southern Lower Michigan into parts of the Ohio Valley. ...Synopsis... On Wednesday morning, a negative-tile shortwave trough will extend from MN to the mid MS Valley, and will weaken as it pivots northeast toward the upper Great Lakes by 00Z. To the west, a broad upper trough with move across the northern Rockies and into the northern Plains, with an intensifying midlevel speed max to around 90 kt by 12Z Thursday over MN. At the surface, low pressure will fill as it moves from MN toward Upper MI, with a shrinking warm sector from north to south due to an occluded front. A plume of 60s F dewpoints will extend as far north as lower MI through afternoon, with mid to upper 60s from AR to the Red River. The trailing front will stall from the OH Valley to the Ozarks, then return north over the Plains as a warm front as a secondary low develops over the High Plains. A strong cold front will move south across the central Plains Wednesday night, reaching northwest TX into central OK by 12Z Thursday. ...Ohio Valley to Lower MI... The combination of a moist pre-frontal air mass as well as heating will lead to 1500-2000 J/kg MUCAPE, beneath 40-50 kt midlevel westerlies with cool temperatures/steep lapse rates aloft. Initial warm/moist advection east of the surface instability axis will likely lead to scattered thunderstorms Wednesday morning, primarily with little hail potential. A greater threat of hail will occur during the peak heating hours, with east/southeast-moving cells developing from southern Lower MI across IN and OH. Rather veered/westerly winds will exist but may favor wind gusts as well. A capping inversion is forecast below 700 mb, but lift along the front should support a narrow, broken line of storms. Northern areas toward Lower MI and northern OH appear to be more favorably positioned relative to the ejecting wave, and cell or two may produce a tornado in that area. Coverage of storms becomes uncertain with southward extend due to subsidence aloft in the wake of the ejecting wave. However, a conditional risk of hail will exist along the boundary southwestward toward the MS River. ...Central Plains/Lower MO Valley Late... As the cold front pushes south overnight, it will meet an unstable air mass, perhaps with over 2000 J/kg MUCAPE. This moisture surge will be aided by an increasing low-level jet, but timing of the front is uncertain, as they typically move faster that forecast. While capping is a concern, the increasing lift may remove CIN, allowing for elevated storms, some of which could produce hail. Given the favorable lapse rates aloft as well as deep-layer shear, low hail probabilities have been added, though the risk area may shift in subsequent outlooks. ..Jewell.. 04/16/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Tue Apr 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN SOUTHWARD INTO PARTS OF INDIANA/OHIO AND TOWARD THE OHIO RIVER... ...SUMMARY... Scattered severe thunderstorms are possible Wednesday afternoon and evening from southern Lower Michigan into parts of the Ohio Valley. ...Synopsis... On Wednesday morning, a negative-tile shortwave trough will extend from MN to the mid MS Valley, and will weaken as it pivots northeast toward the upper Great Lakes by 00Z. To the west, a broad upper trough with move across the northern Rockies and into the northern Plains, with an intensifying midlevel speed max to around 90 kt by 12Z Thursday over MN. At the surface, low pressure will fill as it moves from MN toward Upper MI, with a shrinking warm sector from north to south due to an occluded front. A plume of 60s F dewpoints will extend as far north as lower MI through afternoon, with mid to upper 60s from AR to the Red River. The trailing front will stall from the OH Valley to the Ozarks, then return north over the Plains as a warm front as a secondary low develops over the High Plains. A strong cold front will move south across the central Plains Wednesday night, reaching northwest TX into central OK by 12Z Thursday. ...Ohio Valley to Lower MI... The combination of a moist pre-frontal air mass as well as heating will lead to 1500-2000 J/kg MUCAPE, beneath 40-50 kt midlevel westerlies with cool temperatures/steep lapse rates aloft. Initial warm/moist advection east of the surface instability axis will likely lead to scattered thunderstorms Wednesday morning, primarily with little hail potential. A greater threat of hail will occur during the peak heating hours, with east/southeast-moving cells developing from southern Lower MI across IN and OH. Rather veered/westerly winds will exist but may favor wind gusts as well. A capping inversion is forecast below 700 mb, but lift along the front should support a narrow, broken line of storms. Northern areas toward Lower MI and northern OH appear to be more favorably positioned relative to the ejecting wave, and cell or two may produce a tornado in that area. Coverage of storms becomes uncertain with southward extend due to subsidence aloft in the wake of the ejecting wave. However, a conditional risk of hail will exist along the boundary southwestward toward the MS River. ...Central Plains/Lower MO Valley Late... As the cold front pushes south overnight, it will meet an unstable air mass, perhaps with over 2000 J/kg MUCAPE. This moisture surge will be aided by an increasing low-level jet, but timing of the front is uncertain, as they typically move faster that forecast. While capping is a concern, the increasing lift may remove CIN, allowing for elevated storms, some of which could produce hail. Given the favorable lapse rates aloft as well as deep-layer shear, low hail probabilities have been added, though the risk area may shift in subsequent outlooks. ..Jewell.. 04/16/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Tue Apr 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN SOUTHWARD INTO PARTS OF INDIANA/OHIO AND TOWARD THE OHIO RIVER... ...SUMMARY... Scattered severe thunderstorms are possible Wednesday afternoon and evening from southern Lower Michigan into parts of the Ohio Valley. ...Synopsis... On Wednesday morning, a negative-tile shortwave trough will extend from MN to the mid MS Valley, and will weaken as it pivots northeast toward the upper Great Lakes by 00Z. To the west, a broad upper trough with move across the northern Rockies and into the northern Plains, with an intensifying midlevel speed max to around 90 kt by 12Z Thursday over MN. At the surface, low pressure will fill as it moves from MN toward Upper MI, with a shrinking warm sector from north to south due to an occluded front. A plume of 60s F dewpoints will extend as far north as lower MI through afternoon, with mid to upper 60s from AR to the Red River. The trailing front will stall from the OH Valley to the Ozarks, then return north over the Plains as a warm front as a secondary low develops over the High Plains. A strong cold front will move south across the central Plains Wednesday night, reaching northwest TX into central OK by 12Z Thursday. ...Ohio Valley to Lower MI... The combination of a moist pre-frontal air mass as well as heating will lead to 1500-2000 J/kg MUCAPE, beneath 40-50 kt midlevel westerlies with cool temperatures/steep lapse rates aloft. Initial warm/moist advection east of the surface instability axis will likely lead to scattered thunderstorms Wednesday morning, primarily with little hail potential. A greater threat of hail will occur during the peak heating hours, with east/southeast-moving cells developing from southern Lower MI across IN and OH. Rather veered/westerly winds will exist but may favor wind gusts as well. A capping inversion is forecast below 700 mb, but lift along the front should support a narrow, broken line of storms. Northern areas toward Lower MI and northern OH appear to be more favorably positioned relative to the ejecting wave, and cell or two may produce a tornado in that area. Coverage of storms becomes uncertain with southward extend due to subsidence aloft in the wake of the ejecting wave. However, a conditional risk of hail will exist along the boundary southwestward toward the MS River. ...Central Plains/Lower MO Valley Late... As the cold front pushes south overnight, it will meet an unstable air mass, perhaps with over 2000 J/kg MUCAPE. This moisture surge will be aided by an increasing low-level jet, but timing of the front is uncertain, as they typically move faster that forecast. While capping is a concern, the increasing lift may remove CIN, allowing for elevated storms, some of which could produce hail. Given the favorable lapse rates aloft as well as deep-layer shear, low hail probabilities have been added, though the risk area may shift in subsequent outlooks. ..Jewell.. 04/16/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Tue Apr 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN SOUTHWARD INTO PARTS OF INDIANA/OHIO AND TOWARD THE OHIO RIVER... ...SUMMARY... Scattered severe thunderstorms are possible Wednesday afternoon and evening from southern Lower Michigan into parts of the Ohio Valley. ...Synopsis... On Wednesday morning, a negative-tile shortwave trough will extend from MN to the mid MS Valley, and will weaken as it pivots northeast toward the upper Great Lakes by 00Z. To the west, a broad upper trough with move across the northern Rockies and into the northern Plains, with an intensifying midlevel speed max to around 90 kt by 12Z Thursday over MN. At the surface, low pressure will fill as it moves from MN toward Upper MI, with a shrinking warm sector from north to south due to an occluded front. A plume of 60s F dewpoints will extend as far north as lower MI through afternoon, with mid to upper 60s from AR to the Red River. The trailing front will stall from the OH Valley to the Ozarks, then return north over the Plains as a warm front as a secondary low develops over the High Plains. A strong cold front will move south across the central Plains Wednesday night, reaching northwest TX into central OK by 12Z Thursday. ...Ohio Valley to Lower MI... The combination of a moist pre-frontal air mass as well as heating will lead to 1500-2000 J/kg MUCAPE, beneath 40-50 kt midlevel westerlies with cool temperatures/steep lapse rates aloft. Initial warm/moist advection east of the surface instability axis will likely lead to scattered thunderstorms Wednesday morning, primarily with little hail potential. A greater threat of hail will occur during the peak heating hours, with east/southeast-moving cells developing from southern Lower MI across IN and OH. Rather veered/westerly winds will exist but may favor wind gusts as well. A capping inversion is forecast below 700 mb, but lift along the front should support a narrow, broken line of storms. Northern areas toward Lower MI and northern OH appear to be more favorably positioned relative to the ejecting wave, and cell or two may produce a tornado in that area. Coverage of storms becomes uncertain with southward extend due to subsidence aloft in the wake of the ejecting wave. However, a conditional risk of hail will exist along the boundary southwestward toward the MS River. ...Central Plains/Lower MO Valley Late... As the cold front pushes south overnight, it will meet an unstable air mass, perhaps with over 2000 J/kg MUCAPE. This moisture surge will be aided by an increasing low-level jet, but timing of the front is uncertain, as they typically move faster that forecast. While capping is a concern, the increasing lift may remove CIN, allowing for elevated storms, some of which could produce hail. Given the favorable lapse rates aloft as well as deep-layer shear, low hail probabilities have been added, though the risk area may shift in subsequent outlooks. ..Jewell.. 04/16/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Tue Apr 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN SOUTHWARD INTO PARTS OF INDIANA/OHIO AND TOWARD THE OHIO RIVER... ...SUMMARY... Scattered severe thunderstorms are possible Wednesday afternoon and evening from southern Lower Michigan into parts of the Ohio Valley. ...Synopsis... On Wednesday morning, a negative-tile shortwave trough will extend from MN to the mid MS Valley, and will weaken as it pivots northeast toward the upper Great Lakes by 00Z. To the west, a broad upper trough with move across the northern Rockies and into the northern Plains, with an intensifying midlevel speed max to around 90 kt by 12Z Thursday over MN. At the surface, low pressure will fill as it moves from MN toward Upper MI, with a shrinking warm sector from north to south due to an occluded front. A plume of 60s F dewpoints will extend as far north as lower MI through afternoon, with mid to upper 60s from AR to the Red River. The trailing front will stall from the OH Valley to the Ozarks, then return north over the Plains as a warm front as a secondary low develops over the High Plains. A strong cold front will move south across the central Plains Wednesday night, reaching northwest TX into central OK by 12Z Thursday. ...Ohio Valley to Lower MI... The combination of a moist pre-frontal air mass as well as heating will lead to 1500-2000 J/kg MUCAPE, beneath 40-50 kt midlevel westerlies with cool temperatures/steep lapse rates aloft. Initial warm/moist advection east of the surface instability axis will likely lead to scattered thunderstorms Wednesday morning, primarily with little hail potential. A greater threat of hail will occur during the peak heating hours, with east/southeast-moving cells developing from southern Lower MI across IN and OH. Rather veered/westerly winds will exist but may favor wind gusts as well. A capping inversion is forecast below 700 mb, but lift along the front should support a narrow, broken line of storms. Northern areas toward Lower MI and northern OH appear to be more favorably positioned relative to the ejecting wave, and cell or two may produce a tornado in that area. Coverage of storms becomes uncertain with southward extend due to subsidence aloft in the wake of the ejecting wave. However, a conditional risk of hail will exist along the boundary southwestward toward the MS River. ...Central Plains/Lower MO Valley Late... As the cold front pushes south overnight, it will meet an unstable air mass, perhaps with over 2000 J/kg MUCAPE. This moisture surge will be aided by an increasing low-level jet, but timing of the front is uncertain, as they typically move faster that forecast. While capping is a concern, the increasing lift may remove CIN, allowing for elevated storms, some of which could produce hail. Given the favorable lapse rates aloft as well as deep-layer shear, low hail probabilities have been added, though the risk area may shift in subsequent outlooks. ..Jewell.. 04/16/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Tue Apr 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN SOUTHWARD INTO PARTS OF INDIANA/OHIO AND TOWARD THE OHIO RIVER... ...SUMMARY... Scattered severe thunderstorms are possible Wednesday afternoon and evening from southern Lower Michigan into parts of the Ohio Valley. ...Synopsis... On Wednesday morning, a negative-tile shortwave trough will extend from MN to the mid MS Valley, and will weaken as it pivots northeast toward the upper Great Lakes by 00Z. To the west, a broad upper trough with move across the northern Rockies and into the northern Plains, with an intensifying midlevel speed max to around 90 kt by 12Z Thursday over MN. At the surface, low pressure will fill as it moves from MN toward Upper MI, with a shrinking warm sector from north to south due to an occluded front. A plume of 60s F dewpoints will extend as far north as lower MI through afternoon, with mid to upper 60s from AR to the Red River. The trailing front will stall from the OH Valley to the Ozarks, then return north over the Plains as a warm front as a secondary low develops over the High Plains. A strong cold front will move south across the central Plains Wednesday night, reaching northwest TX into central OK by 12Z Thursday. ...Ohio Valley to Lower MI... The combination of a moist pre-frontal air mass as well as heating will lead to 1500-2000 J/kg MUCAPE, beneath 40-50 kt midlevel westerlies with cool temperatures/steep lapse rates aloft. Initial warm/moist advection east of the surface instability axis will likely lead to scattered thunderstorms Wednesday morning, primarily with little hail potential. A greater threat of hail will occur during the peak heating hours, with east/southeast-moving cells developing from southern Lower MI across IN and OH. Rather veered/westerly winds will exist but may favor wind gusts as well. A capping inversion is forecast below 700 mb, but lift along the front should support a narrow, broken line of storms. Northern areas toward Lower MI and northern OH appear to be more favorably positioned relative to the ejecting wave, and cell or two may produce a tornado in that area. Coverage of storms becomes uncertain with southward extend due to subsidence aloft in the wake of the ejecting wave. However, a conditional risk of hail will exist along the boundary southwestward toward the MS River. ...Central Plains/Lower MO Valley Late... As the cold front pushes south overnight, it will meet an unstable air mass, perhaps with over 2000 J/kg MUCAPE. This moisture surge will be aided by an increasing low-level jet, but timing of the front is uncertain, as they typically move faster that forecast. While capping is a concern, the increasing lift may remove CIN, allowing for elevated storms, some of which could produce hail. Given the favorable lapse rates aloft as well as deep-layer shear, low hail probabilities have been added, though the risk area may shift in subsequent outlooks. ..Jewell.. 04/16/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Tue Apr 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN SOUTHWARD INTO PARTS OF INDIANA/OHIO AND TOWARD THE OHIO RIVER... ...SUMMARY... Scattered severe thunderstorms are possible Wednesday afternoon and evening from southern Lower Michigan into parts of the Ohio Valley. ...Synopsis... On Wednesday morning, a negative-tile shortwave trough will extend from MN to the mid MS Valley, and will weaken as it pivots northeast toward the upper Great Lakes by 00Z. To the west, a broad upper trough with move across the northern Rockies and into the northern Plains, with an intensifying midlevel speed max to around 90 kt by 12Z Thursday over MN. At the surface, low pressure will fill as it moves from MN toward Upper MI, with a shrinking warm sector from north to south due to an occluded front. A plume of 60s F dewpoints will extend as far north as lower MI through afternoon, with mid to upper 60s from AR to the Red River. The trailing front will stall from the OH Valley to the Ozarks, then return north over the Plains as a warm front as a secondary low develops over the High Plains. A strong cold front will move south across the central Plains Wednesday night, reaching northwest TX into central OK by 12Z Thursday. ...Ohio Valley to Lower MI... The combination of a moist pre-frontal air mass as well as heating will lead to 1500-2000 J/kg MUCAPE, beneath 40-50 kt midlevel westerlies with cool temperatures/steep lapse rates aloft. Initial warm/moist advection east of the surface instability axis will likely lead to scattered thunderstorms Wednesday morning, primarily with little hail potential. A greater threat of hail will occur during the peak heating hours, with east/southeast-moving cells developing from southern Lower MI across IN and OH. Rather veered/westerly winds will exist but may favor wind gusts as well. A capping inversion is forecast below 700 mb, but lift along the front should support a narrow, broken line of storms. Northern areas toward Lower MI and northern OH appear to be more favorably positioned relative to the ejecting wave, and cell or two may produce a tornado in that area. Coverage of storms becomes uncertain with southward extend due to subsidence aloft in the wake of the ejecting wave. However, a conditional risk of hail will exist along the boundary southwestward toward the MS River. ...Central Plains/Lower MO Valley Late... As the cold front pushes south overnight, it will meet an unstable air mass, perhaps with over 2000 J/kg MUCAPE. This moisture surge will be aided by an increasing low-level jet, but timing of the front is uncertain, as they typically move faster that forecast. While capping is a concern, the increasing lift may remove CIN, allowing for elevated storms, some of which could produce hail. Given the favorable lapse rates aloft as well as deep-layer shear, low hail probabilities have been added, though the risk area may shift in subsequent outlooks. ..Jewell.. 04/16/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Tue Apr 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN SOUTHWARD INTO PARTS OF INDIANA/OHIO AND TOWARD THE OHIO RIVER... ...SUMMARY... Scattered severe thunderstorms are possible Wednesday afternoon and evening from southern Lower Michigan into parts of the Ohio Valley. ...Synopsis... On Wednesday morning, a negative-tile shortwave trough will extend from MN to the mid MS Valley, and will weaken as it pivots northeast toward the upper Great Lakes by 00Z. To the west, a broad upper trough with move across the northern Rockies and into the northern Plains, with an intensifying midlevel speed max to around 90 kt by 12Z Thursday over MN. At the surface, low pressure will fill as it moves from MN toward Upper MI, with a shrinking warm sector from north to south due to an occluded front. A plume of 60s F dewpoints will extend as far north as lower MI through afternoon, with mid to upper 60s from AR to the Red River. The trailing front will stall from the OH Valley to the Ozarks, then return north over the Plains as a warm front as a secondary low develops over the High Plains. A strong cold front will move south across the central Plains Wednesday night, reaching northwest TX into central OK by 12Z Thursday. ...Ohio Valley to Lower MI... The combination of a moist pre-frontal air mass as well as heating will lead to 1500-2000 J/kg MUCAPE, beneath 40-50 kt midlevel westerlies with cool temperatures/steep lapse rates aloft. Initial warm/moist advection east of the surface instability axis will likely lead to scattered thunderstorms Wednesday morning, primarily with little hail potential. A greater threat of hail will occur during the peak heating hours, with east/southeast-moving cells developing from southern Lower MI across IN and OH. Rather veered/westerly winds will exist but may favor wind gusts as well. A capping inversion is forecast below 700 mb, but lift along the front should support a narrow, broken line of storms. Northern areas toward Lower MI and northern OH appear to be more favorably positioned relative to the ejecting wave, and cell or two may produce a tornado in that area. Coverage of storms becomes uncertain with southward extend due to subsidence aloft in the wake of the ejecting wave. However, a conditional risk of hail will exist along the boundary southwestward toward the MS River. ...Central Plains/Lower MO Valley Late... As the cold front pushes south overnight, it will meet an unstable air mass, perhaps with over 2000 J/kg MUCAPE. This moisture surge will be aided by an increasing low-level jet, but timing of the front is uncertain, as they typically move faster that forecast. While capping is a concern, the increasing lift may remove CIN, allowing for elevated storms, some of which could produce hail. Given the favorable lapse rates aloft as well as deep-layer shear, low hail probabilities have been added, though the risk area may shift in subsequent outlooks. ..Jewell.. 04/16/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Tue Apr 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN SOUTHWARD INTO PARTS OF INDIANA/OHIO AND TOWARD THE OHIO RIVER... ...SUMMARY... Scattered severe thunderstorms are possible Wednesday afternoon and evening from southern Lower Michigan into parts of the Ohio Valley. ...Synopsis... On Wednesday morning, a negative-tile shortwave trough will extend from MN to the mid MS Valley, and will weaken as it pivots northeast toward the upper Great Lakes by 00Z. To the west, a broad upper trough with move across the northern Rockies and into the northern Plains, with an intensifying midlevel speed max to around 90 kt by 12Z Thursday over MN. At the surface, low pressure will fill as it moves from MN toward Upper MI, with a shrinking warm sector from north to south due to an occluded front. A plume of 60s F dewpoints will extend as far north as lower MI through afternoon, with mid to upper 60s from AR to the Red River. The trailing front will stall from the OH Valley to the Ozarks, then return north over the Plains as a warm front as a secondary low develops over the High Plains. A strong cold front will move south across the central Plains Wednesday night, reaching northwest TX into central OK by 12Z Thursday. ...Ohio Valley to Lower MI... The combination of a moist pre-frontal air mass as well as heating will lead to 1500-2000 J/kg MUCAPE, beneath 40-50 kt midlevel westerlies with cool temperatures/steep lapse rates aloft. Initial warm/moist advection east of the surface instability axis will likely lead to scattered thunderstorms Wednesday morning, primarily with little hail potential. A greater threat of hail will occur during the peak heating hours, with east/southeast-moving cells developing from southern Lower MI across IN and OH. Rather veered/westerly winds will exist but may favor wind gusts as well. A capping inversion is forecast below 700 mb, but lift along the front should support a narrow, broken line of storms. Northern areas toward Lower MI and northern OH appear to be more favorably positioned relative to the ejecting wave, and cell or two may produce a tornado in that area. Coverage of storms becomes uncertain with southward extend due to subsidence aloft in the wake of the ejecting wave. However, a conditional risk of hail will exist along the boundary southwestward toward the MS River. ...Central Plains/Lower MO Valley Late... As the cold front pushes south overnight, it will meet an unstable air mass, perhaps with over 2000 J/kg MUCAPE. This moisture surge will be aided by an increasing low-level jet, but timing of the front is uncertain, as they typically move faster that forecast. While capping is a concern, the increasing lift may remove CIN, allowing for elevated storms, some of which could produce hail. Given the favorable lapse rates aloft as well as deep-layer shear, low hail probabilities have been added, though the risk area may shift in subsequent outlooks. ..Jewell.. 04/16/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Tue Apr 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN SOUTHWARD INTO PARTS OF INDIANA/OHIO AND TOWARD THE OHIO RIVER... ...SUMMARY... Scattered severe thunderstorms are possible Wednesday afternoon and evening from southern Lower Michigan into parts of the Ohio Valley. ...Synopsis... On Wednesday morning, a negative-tile shortwave trough will extend from MN to the mid MS Valley, and will weaken as it pivots northeast toward the upper Great Lakes by 00Z. To the west, a broad upper trough with move across the northern Rockies and into the northern Plains, with an intensifying midlevel speed max to around 90 kt by 12Z Thursday over MN. At the surface, low pressure will fill as it moves from MN toward Upper MI, with a shrinking warm sector from north to south due to an occluded front. A plume of 60s F dewpoints will extend as far north as lower MI through afternoon, with mid to upper 60s from AR to the Red River. The trailing front will stall from the OH Valley to the Ozarks, then return north over the Plains as a warm front as a secondary low develops over the High Plains. A strong cold front will move south across the central Plains Wednesday night, reaching northwest TX into central OK by 12Z Thursday. ...Ohio Valley to Lower MI... The combination of a moist pre-frontal air mass as well as heating will lead to 1500-2000 J/kg MUCAPE, beneath 40-50 kt midlevel westerlies with cool temperatures/steep lapse rates aloft. Initial warm/moist advection east of the surface instability axis will likely lead to scattered thunderstorms Wednesday morning, primarily with little hail potential. A greater threat of hail will occur during the peak heating hours, with east/southeast-moving cells developing from southern Lower MI across IN and OH. Rather veered/westerly winds will exist but may favor wind gusts as well. A capping inversion is forecast below 700 mb, but lift along the front should support a narrow, broken line of storms. Northern areas toward Lower MI and northern OH appear to be more favorably positioned relative to the ejecting wave, and cell or two may produce a tornado in that area. Coverage of storms becomes uncertain with southward extend due to subsidence aloft in the wake of the ejecting wave. However, a conditional risk of hail will exist along the boundary southwestward toward the MS River. ...Central Plains/Lower MO Valley Late... As the cold front pushes south overnight, it will meet an unstable air mass, perhaps with over 2000 J/kg MUCAPE. This moisture surge will be aided by an increasing low-level jet, but timing of the front is uncertain, as they typically move faster that forecast. While capping is a concern, the increasing lift may remove CIN, allowing for elevated storms, some of which could produce hail. Given the favorable lapse rates aloft as well as deep-layer shear, low hail probabilities have been added, though the risk area may shift in subsequent outlooks. ..Jewell.. 04/16/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Tue Apr 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN SOUTHWARD INTO PARTS OF INDIANA/OHIO AND TOWARD THE OHIO RIVER... ...SUMMARY... Scattered severe thunderstorms are possible Wednesday afternoon and evening from southern Lower Michigan into parts of the Ohio Valley. ...Synopsis... On Wednesday morning, a negative-tile shortwave trough will extend from MN to the mid MS Valley, and will weaken as it pivots northeast toward the upper Great Lakes by 00Z. To the west, a broad upper trough with move across the northern Rockies and into the northern Plains, with an intensifying midlevel speed max to around 90 kt by 12Z Thursday over MN. At the surface, low pressure will fill as it moves from MN toward Upper MI, with a shrinking warm sector from north to south due to an occluded front. A plume of 60s F dewpoints will extend as far north as lower MI through afternoon, with mid to upper 60s from AR to the Red River. The trailing front will stall from the OH Valley to the Ozarks, then return north over the Plains as a warm front as a secondary low develops over the High Plains. A strong cold front will move south across the central Plains Wednesday night, reaching northwest TX into central OK by 12Z Thursday. ...Ohio Valley to Lower MI... The combination of a moist pre-frontal air mass as well as heating will lead to 1500-2000 J/kg MUCAPE, beneath 40-50 kt midlevel westerlies with cool temperatures/steep lapse rates aloft. Initial warm/moist advection east of the surface instability axis will likely lead to scattered thunderstorms Wednesday morning, primarily with little hail potential. A greater threat of hail will occur during the peak heating hours, with east/southeast-moving cells developing from southern Lower MI across IN and OH. Rather veered/westerly winds will exist but may favor wind gusts as well. A capping inversion is forecast below 700 mb, but lift along the front should support a narrow, broken line of storms. Northern areas toward Lower MI and northern OH appear to be more favorably positioned relative to the ejecting wave, and cell or two may produce a tornado in that area. Coverage of storms becomes uncertain with southward extend due to subsidence aloft in the wake of the ejecting wave. However, a conditional risk of hail will exist along the boundary southwestward toward the MS River. ...Central Plains/Lower MO Valley Late... As the cold front pushes south overnight, it will meet an unstable air mass, perhaps with over 2000 J/kg MUCAPE. This moisture surge will be aided by an increasing low-level jet, but timing of the front is uncertain, as they typically move faster that forecast. While capping is a concern, the increasing lift may remove CIN, allowing for elevated storms, some of which could produce hail. Given the favorable lapse rates aloft as well as deep-layer shear, low hail probabilities have been added, though the risk area may shift in subsequent outlooks. ..Jewell.. 04/16/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Tue Apr 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN SOUTHWARD INTO PARTS OF INDIANA/OHIO AND TOWARD THE OHIO RIVER... ...SUMMARY... Scattered severe thunderstorms are possible Wednesday afternoon and evening from southern Lower Michigan into parts of the Ohio Valley. ...Synopsis... On Wednesday morning, a negative-tile shortwave trough will extend from MN to the mid MS Valley, and will weaken as it pivots northeast toward the upper Great Lakes by 00Z. To the west, a broad upper trough with move across the northern Rockies and into the northern Plains, with an intensifying midlevel speed max to around 90 kt by 12Z Thursday over MN. At the surface, low pressure will fill as it moves from MN toward Upper MI, with a shrinking warm sector from north to south due to an occluded front. A plume of 60s F dewpoints will extend as far north as lower MI through afternoon, with mid to upper 60s from AR to the Red River. The trailing front will stall from the OH Valley to the Ozarks, then return north over the Plains as a warm front as a secondary low develops over the High Plains. A strong cold front will move south across the central Plains Wednesday night, reaching northwest TX into central OK by 12Z Thursday. ...Ohio Valley to Lower MI... The combination of a moist pre-frontal air mass as well as heating will lead to 1500-2000 J/kg MUCAPE, beneath 40-50 kt midlevel westerlies with cool temperatures/steep lapse rates aloft. Initial warm/moist advection east of the surface instability axis will likely lead to scattered thunderstorms Wednesday morning, primarily with little hail potential. A greater threat of hail will occur during the peak heating hours, with east/southeast-moving cells developing from southern Lower MI across IN and OH. Rather veered/westerly winds will exist but may favor wind gusts as well. A capping inversion is forecast below 700 mb, but lift along the front should support a narrow, broken line of storms. Northern areas toward Lower MI and northern OH appear to be more favorably positioned relative to the ejecting wave, and cell or two may produce a tornado in that area. Coverage of storms becomes uncertain with southward extend due to subsidence aloft in the wake of the ejecting wave. However, a conditional risk of hail will exist along the boundary southwestward toward the MS River. ...Central Plains/Lower MO Valley Late... As the cold front pushes south overnight, it will meet an unstable air mass, perhaps with over 2000 J/kg MUCAPE. This moisture surge will be aided by an increasing low-level jet, but timing of the front is uncertain, as they typically move faster that forecast. While capping is a concern, the increasing lift may remove CIN, allowing for elevated storms, some of which could produce hail. Given the favorable lapse rates aloft as well as deep-layer shear, low hail probabilities have been added, though the risk area may shift in subsequent outlooks. ..Jewell.. 04/16/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Tue Apr 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN SOUTHWARD INTO PARTS OF INDIANA/OHIO AND TOWARD THE OHIO RIVER... ...SUMMARY... Scattered severe thunderstorms are possible Wednesday afternoon and evening from southern Lower Michigan into parts of the Ohio Valley. ...Synopsis... On Wednesday morning, a negative-tile shortwave trough will extend from MN to the mid MS Valley, and will weaken as it pivots northeast toward the upper Great Lakes by 00Z. To the west, a broad upper trough with move across the northern Rockies and into the northern Plains, with an intensifying midlevel speed max to around 90 kt by 12Z Thursday over MN. At the surface, low pressure will fill as it moves from MN toward Upper MI, with a shrinking warm sector from north to south due to an occluded front. A plume of 60s F dewpoints will extend as far north as lower MI through afternoon, with mid to upper 60s from AR to the Red River. The trailing front will stall from the OH Valley to the Ozarks, then return north over the Plains as a warm front as a secondary low develops over the High Plains. A strong cold front will move south across the central Plains Wednesday night, reaching northwest TX into central OK by 12Z Thursday. ...Ohio Valley to Lower MI... The combination of a moist pre-frontal air mass as well as heating will lead to 1500-2000 J/kg MUCAPE, beneath 40-50 kt midlevel westerlies with cool temperatures/steep lapse rates aloft. Initial warm/moist advection east of the surface instability axis will likely lead to scattered thunderstorms Wednesday morning, primarily with little hail potential. A greater threat of hail will occur during the peak heating hours, with east/southeast-moving cells developing from southern Lower MI across IN and OH. Rather veered/westerly winds will exist but may favor wind gusts as well. A capping inversion is forecast below 700 mb, but lift along the front should support a narrow, broken line of storms. Northern areas toward Lower MI and northern OH appear to be more favorably positioned relative to the ejecting wave, and cell or two may produce a tornado in that area. Coverage of storms becomes uncertain with southward extend due to subsidence aloft in the wake of the ejecting wave. However, a conditional risk of hail will exist along the boundary southwestward toward the MS River. ...Central Plains/Lower MO Valley Late... As the cold front pushes south overnight, it will meet an unstable air mass, perhaps with over 2000 J/kg MUCAPE. This moisture surge will be aided by an increasing low-level jet, but timing of the front is uncertain, as they typically move faster that forecast. While capping is a concern, the increasing lift may remove CIN, allowing for elevated storms, some of which could produce hail. Given the favorable lapse rates aloft as well as deep-layer shear, low hail probabilities have been added, though the risk area may shift in subsequent outlooks. ..Jewell.. 04/16/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Tue Apr 16 2024 Valid 171200Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM LOWER MICHIGAN SOUTHWARD INTO PARTS OF INDIANA/OHIO AND TOWARD THE OHIO RIVER... ...SUMMARY... Scattered severe thunderstorms are possible Wednesday afternoon and evening from southern Lower Michigan into parts of the Ohio Valley. ...Synopsis... On Wednesday morning, a negative-tile shortwave trough will extend from MN to the mid MS Valley, and will weaken as it pivots northeast toward the upper Great Lakes by 00Z. To the west, a broad upper trough with move across the northern Rockies and into the northern Plains, with an intensifying midlevel speed max to around 90 kt by 12Z Thursday over MN. At the surface, low pressure will fill as it moves from MN toward Upper MI, with a shrinking warm sector from north to south due to an occluded front. A plume of 60s F dewpoints will extend as far north as lower MI through afternoon, with mid to upper 60s from AR to the Red River. The trailing front will stall from the OH Valley to the Ozarks, then return north over the Plains as a warm front as a secondary low develops over the High Plains. A strong cold front will move south across the central Plains Wednesday night, reaching northwest TX into central OK by 12Z Thursday. ...Ohio Valley to Lower MI... The combination of a moist pre-frontal air mass as well as heating will lead to 1500-2000 J/kg MUCAPE, beneath 40-50 kt midlevel westerlies with cool temperatures/steep lapse rates aloft. Initial warm/moist advection east of the surface instability axis will likely lead to scattered thunderstorms Wednesday morning, primarily with little hail potential. A greater threat of hail will occur during the peak heating hours, with east/southeast-moving cells developing from southern Lower MI across IN and OH. Rather veered/westerly winds will exist but may favor wind gusts as well. A capping inversion is forecast below 700 mb, but lift along the front should support a narrow, broken line of storms. Northern areas toward Lower MI and northern OH appear to be more favorably positioned relative to the ejecting wave, and cell or two may produce a tornado in that area. Coverage of storms becomes uncertain with southward extend due to subsidence aloft in the wake of the ejecting wave. However, a conditional risk of hail will exist along the boundary southwestward toward the MS River. ...Central Plains/Lower MO Valley Late... As the cold front pushes south overnight, it will meet an unstable air mass, perhaps with over 2000 J/kg MUCAPE. This moisture surge will be aided by an increasing low-level jet, but timing of the front is uncertain, as they typically move faster that forecast. While capping is a concern, the increasing lift may remove CIN, allowing for elevated storms, some of which could produce hail. Given the favorable lapse rates aloft as well as deep-layer shear, low hail probabilities have been added, though the risk area may shift in subsequent outlooks. ..Jewell.. 04/16/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1238 AM CDT Tue Apr 16 2024 Valid 161200Z - 171200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDWEST... ...SUMMARY... Scattered severe thunderstorms are likely today, centered mostly over the midwestern states of northern Missouri/Iowa/northwestern Illinois. Hail, wind, and tornadoes are expected in this corridor. More isolated activity could develop as far south as the Ozarks of northern Arkansas. ...Midwest... Upper low is currently located over southeast CO, and will soon begin ejecting northeast in line with latest model guidance into the central Plains. By 18z this feature should advance into eastern NE as 90kt 500mb speed max translates through the base of the trough, across northern OK, into northwestern MO. In response to this dynamic system, strong LLJ will focus across the eastern Plains early then shift into the mid/upper MS Valley by 18z. Low-level warm advection is expected to prove instrumental in early-day convection, in association with the LLJ. This activity should be ongoing at the start of the period, focused over the mid-MO Valley. Subsequent movement/development is expected downstream across IA/southern MN as the warm conveyor shifts east. While strong shear will support this convection, the primary concern will be with secondary development in association with a pronounced mid-level dry slot. Latest model guidance suggests surface-3km lapse rates will steepen to near 9 C/km across southeast NE/northeast KS by 18z. Leading edge of this steeper lapse-rate plume will advance across western IA, immediately ahead of the surface low. As a result, boundary-layer heating will contribute to substantial buoyancy and some areas may experience MLCAPE near 2000 J/kg. Surface-based parcels are forecast to be uninhibited by 17-18z across western IA. Current thinking is scattered convection should develop within this zone of destabilization then spread northeast. Surface warm front is expected to serve as a northern limit to surface-based convection, along with any appreciable tornado risk. Large hail can be expected with supercells, and favorable shear will support the potential for tornadoes, a few potentially strong. This activity will spread across IA/extreme northern MO into northwestern IL during the evening. Farther south into the Ozarks, severe threat is much more conditional. Forecast soundings exhibit poor lapse rates and at least weak inhibition through much of the period. It's not real clear how robust updrafts will be, despite the strong shear, given the marginal lapse-rate environment. Will maintain SLGT Risk into this portion of the lower MS Valley but convection may struggle much of the period. ..Darrow/Lyons.. 04/16/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1238 AM CDT Tue Apr 16 2024 Valid 161200Z - 171200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDWEST... ...SUMMARY... Scattered severe thunderstorms are likely today, centered mostly over the midwestern states of northern Missouri/Iowa/northwestern Illinois. Hail, wind, and tornadoes are expected in this corridor. More isolated activity could develop as far south as the Ozarks of northern Arkansas. ...Midwest... Upper low is currently located over southeast CO, and will soon begin ejecting northeast in line with latest model guidance into the central Plains. By 18z this feature should advance into eastern NE as 90kt 500mb speed max translates through the base of the trough, across northern OK, into northwestern MO. In response to this dynamic system, strong LLJ will focus across the eastern Plains early then shift into the mid/upper MS Valley by 18z. Low-level warm advection is expected to prove instrumental in early-day convection, in association with the LLJ. This activity should be ongoing at the start of the period, focused over the mid-MO Valley. Subsequent movement/development is expected downstream across IA/southern MN as the warm conveyor shifts east. While strong shear will support this convection, the primary concern will be with secondary development in association with a pronounced mid-level dry slot. Latest model guidance suggests surface-3km lapse rates will steepen to near 9 C/km across southeast NE/northeast KS by 18z. Leading edge of this steeper lapse-rate plume will advance across western IA, immediately ahead of the surface low. As a result, boundary-layer heating will contribute to substantial buoyancy and some areas may experience MLCAPE near 2000 J/kg. Surface-based parcels are forecast to be uninhibited by 17-18z across western IA. Current thinking is scattered convection should develop within this zone of destabilization then spread northeast. Surface warm front is expected to serve as a northern limit to surface-based convection, along with any appreciable tornado risk. Large hail can be expected with supercells, and favorable shear will support the potential for tornadoes, a few potentially strong. This activity will spread across IA/extreme northern MO into northwestern IL during the evening. Farther south into the Ozarks, severe threat is much more conditional. Forecast soundings exhibit poor lapse rates and at least weak inhibition through much of the period. It's not real clear how robust updrafts will be, despite the strong shear, given the marginal lapse-rate environment. Will maintain SLGT Risk into this portion of the lower MS Valley but convection may struggle much of the period. ..Darrow/Lyons.. 04/16/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1238 AM CDT Tue Apr 16 2024 Valid 161200Z - 171200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDWEST... ...SUMMARY... Scattered severe thunderstorms are likely today, centered mostly over the midwestern states of northern Missouri/Iowa/northwestern Illinois. Hail, wind, and tornadoes are expected in this corridor. More isolated activity could develop as far south as the Ozarks of northern Arkansas. ...Midwest... Upper low is currently located over southeast CO, and will soon begin ejecting northeast in line with latest model guidance into the central Plains. By 18z this feature should advance into eastern NE as 90kt 500mb speed max translates through the base of the trough, across northern OK, into northwestern MO. In response to this dynamic system, strong LLJ will focus across the eastern Plains early then shift into the mid/upper MS Valley by 18z. Low-level warm advection is expected to prove instrumental in early-day convection, in association with the LLJ. This activity should be ongoing at the start of the period, focused over the mid-MO Valley. Subsequent movement/development is expected downstream across IA/southern MN as the warm conveyor shifts east. While strong shear will support this convection, the primary concern will be with secondary development in association with a pronounced mid-level dry slot. Latest model guidance suggests surface-3km lapse rates will steepen to near 9 C/km across southeast NE/northeast KS by 18z. Leading edge of this steeper lapse-rate plume will advance across western IA, immediately ahead of the surface low. As a result, boundary-layer heating will contribute to substantial buoyancy and some areas may experience MLCAPE near 2000 J/kg. Surface-based parcels are forecast to be uninhibited by 17-18z across western IA. Current thinking is scattered convection should develop within this zone of destabilization then spread northeast. Surface warm front is expected to serve as a northern limit to surface-based convection, along with any appreciable tornado risk. Large hail can be expected with supercells, and favorable shear will support the potential for tornadoes, a few potentially strong. This activity will spread across IA/extreme northern MO into northwestern IL during the evening. Farther south into the Ozarks, severe threat is much more conditional. Forecast soundings exhibit poor lapse rates and at least weak inhibition through much of the period. It's not real clear how robust updrafts will be, despite the strong shear, given the marginal lapse-rate environment. Will maintain SLGT Risk into this portion of the lower MS Valley but convection may struggle much of the period. ..Darrow/Lyons.. 04/16/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1238 AM CDT Tue Apr 16 2024 Valid 161200Z - 171200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDWEST... ...SUMMARY... Scattered severe thunderstorms are likely today, centered mostly over the midwestern states of northern Missouri/Iowa/northwestern Illinois. Hail, wind, and tornadoes are expected in this corridor. More isolated activity could develop as far south as the Ozarks of northern Arkansas. ...Midwest... Upper low is currently located over southeast CO, and will soon begin ejecting northeast in line with latest model guidance into the central Plains. By 18z this feature should advance into eastern NE as 90kt 500mb speed max translates through the base of the trough, across northern OK, into northwestern MO. In response to this dynamic system, strong LLJ will focus across the eastern Plains early then shift into the mid/upper MS Valley by 18z. Low-level warm advection is expected to prove instrumental in early-day convection, in association with the LLJ. This activity should be ongoing at the start of the period, focused over the mid-MO Valley. Subsequent movement/development is expected downstream across IA/southern MN as the warm conveyor shifts east. While strong shear will support this convection, the primary concern will be with secondary development in association with a pronounced mid-level dry slot. Latest model guidance suggests surface-3km lapse rates will steepen to near 9 C/km across southeast NE/northeast KS by 18z. Leading edge of this steeper lapse-rate plume will advance across western IA, immediately ahead of the surface low. As a result, boundary-layer heating will contribute to substantial buoyancy and some areas may experience MLCAPE near 2000 J/kg. Surface-based parcels are forecast to be uninhibited by 17-18z across western IA. Current thinking is scattered convection should develop within this zone of destabilization then spread northeast. Surface warm front is expected to serve as a northern limit to surface-based convection, along with any appreciable tornado risk. Large hail can be expected with supercells, and favorable shear will support the potential for tornadoes, a few potentially strong. This activity will spread across IA/extreme northern MO into northwestern IL during the evening. Farther south into the Ozarks, severe threat is much more conditional. Forecast soundings exhibit poor lapse rates and at least weak inhibition through much of the period. It's not real clear how robust updrafts will be, despite the strong shear, given the marginal lapse-rate environment. Will maintain SLGT Risk into this portion of the lower MS Valley but convection may struggle much of the period. ..Darrow/Lyons.. 04/16/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1238 AM CDT Tue Apr 16 2024 Valid 161200Z - 171200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDWEST... ...SUMMARY... Scattered severe thunderstorms are likely today, centered mostly over the midwestern states of northern Missouri/Iowa/northwestern Illinois. Hail, wind, and tornadoes are expected in this corridor. More isolated activity could develop as far south as the Ozarks of northern Arkansas. ...Midwest... Upper low is currently located over southeast CO, and will soon begin ejecting northeast in line with latest model guidance into the central Plains. By 18z this feature should advance into eastern NE as 90kt 500mb speed max translates through the base of the trough, across northern OK, into northwestern MO. In response to this dynamic system, strong LLJ will focus across the eastern Plains early then shift into the mid/upper MS Valley by 18z. Low-level warm advection is expected to prove instrumental in early-day convection, in association with the LLJ. This activity should be ongoing at the start of the period, focused over the mid-MO Valley. Subsequent movement/development is expected downstream across IA/southern MN as the warm conveyor shifts east. While strong shear will support this convection, the primary concern will be with secondary development in association with a pronounced mid-level dry slot. Latest model guidance suggests surface-3km lapse rates will steepen to near 9 C/km across southeast NE/northeast KS by 18z. Leading edge of this steeper lapse-rate plume will advance across western IA, immediately ahead of the surface low. As a result, boundary-layer heating will contribute to substantial buoyancy and some areas may experience MLCAPE near 2000 J/kg. Surface-based parcels are forecast to be uninhibited by 17-18z across western IA. Current thinking is scattered convection should develop within this zone of destabilization then spread northeast. Surface warm front is expected to serve as a northern limit to surface-based convection, along with any appreciable tornado risk. Large hail can be expected with supercells, and favorable shear will support the potential for tornadoes, a few potentially strong. This activity will spread across IA/extreme northern MO into northwestern IL during the evening. Farther south into the Ozarks, severe threat is much more conditional. Forecast soundings exhibit poor lapse rates and at least weak inhibition through much of the period. It's not real clear how robust updrafts will be, despite the strong shear, given the marginal lapse-rate environment. Will maintain SLGT Risk into this portion of the lower MS Valley but convection may struggle much of the period. ..Darrow/Lyons.. 04/16/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1238 AM CDT Tue Apr 16 2024 Valid 161200Z - 171200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE MIDWEST... ...SUMMARY... Scattered severe thunderstorms are likely today, centered mostly over the midwestern states of northern Missouri/Iowa/northwestern Illinois. Hail, wind, and tornadoes are expected in this corridor. More isolated activity could develop as far south as the Ozarks of northern Arkansas. ...Midwest... Upper low is currently located over southeast CO, and will soon begin ejecting northeast in line with latest model guidance into the central Plains. By 18z this feature should advance into eastern NE as 90kt 500mb speed max translates through the base of the trough, across northern OK, into northwestern MO. In response to this dynamic system, strong LLJ will focus across the eastern Plains early then shift into the mid/upper MS Valley by 18z. Low-level warm advection is expected to prove instrumental in early-day convection, in association with the LLJ. This activity should be ongoing at the start of the period, focused over the mid-MO Valley. Subsequent movement/development is expected downstream across IA/southern MN as the warm conveyor shifts east. While strong shear will support this convection, the primary concern will be with secondary development in association with a pronounced mid-level dry slot. Latest model guidance suggests surface-3km lapse rates will steepen to near 9 C/km across southeast NE/northeast KS by 18z. Leading edge of this steeper lapse-rate plume will advance across western IA, immediately ahead of the surface low. As a result, boundary-layer heating will contribute to substantial buoyancy and some areas may experience MLCAPE near 2000 J/kg. Surface-based parcels are forecast to be uninhibited by 17-18z across western IA. Current thinking is scattered convection should develop within this zone of destabilization then spread northeast. Surface warm front is expected to serve as a northern limit to surface-based convection, along with any appreciable tornado risk. Large hail can be expected with supercells, and favorable shear will support the potential for tornadoes, a few potentially strong. This activity will spread across IA/extreme northern MO into northwestern IL during the evening. Farther south into the Ozarks, severe threat is much more conditional. Forecast soundings exhibit poor lapse rates and at least weak inhibition through much of the period. It's not real clear how robust updrafts will be, despite the strong shear, given the marginal lapse-rate environment. Will maintain SLGT Risk into this portion of the lower MS Valley but convection may struggle much of the period. ..Darrow/Lyons.. 04/16/2024 Read more