Severe Storms

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1224 AM CDT Tue Jun 18 2024 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE SOUTHERN HIGH PLAINS...FROM PARTS OF IOWA INTO SOUTHERN WISCONSIN...AND OVER FAR SOUTHERN TEXAS... ...SUMMARY... Locally strong gusts may occur with storms over the southern High Plains, and from parts of Iowa into southern Wisconsin. A brief tornado cannot be ruled out over far southern Texas late Wednesday and Wednesday night in association with Potential Tropical Cyclone 1. ...Synopsis... The tail end of an upper trough will sweep across the northern Plains and upper MS Valley during the day, with primary speed max well into Ontario. Meanwhile, a strong upper ridge will extend from the OH Valley into the Northeast, with rising heights and subsidence developing over the Plains and south of the departing wave. At the surface, a cold front will decelerate into WI, becoming stationary during the evening westward into KS and toward northeast NM. While a moist air mass will exist ahead of this front, warming temperatures aloft and weakening lift will minimize severe potential across those areas. However, easterly upslope flow may result in a few strong storms into NM. Farther south, a very moist air mass will push west across the western Gulf of Mexico with upper 70s F dewpoints across southern TX. Overall wind fields are likely to increase as Potential Tropical Cyclone 1 develops, and possibly becomes a TS per NHC guidance. ...From southern WI to northeast NM... Areas of thunderstorms are likely to be ongoing Wednesday morning over parts of the central Plains, potentially producing strong outflow winds. This convection is expected to weaken during the day, with a rejuvenation along portions of the boundary during the afternoon. The most likely areas for isolated severe gusts appear to be over the IA to WI/IL portion of the boundary in closer proximity to the exiting upper wave, and in the upslope region over eastern NM. In both areas, neither shear nor instability will be particularly strong, but the front should provide a focus for development in a marginally unstable environment. In addition to gusty winds, cells over northeast NM into the OK/TX Panhandles may produce marginally severe hail as veering winds with height favor cellular storm mode. ...Far southern TX... Substantial convection with the potential tropical cyclone will move westward from the Gulf of Mexico and into southern TX, providing heavy rainfall and increasing winds. Official NHC guidance brings the system to tropical storm strength prior to landfall over Mexico early Thursday morning, which will maintain moist easterly winds across TX. Forecast soundings from various models depict upper 70s F dewpoints will favor sufficient SBCAPE for a few strong storms given 30-50 kt winds through the lowest few km AGL, veering with height. The combination of a very moist air mass with potentially strong low-level shear may favor a minimal tornado risk over the region, and low tornado probabilities have been introduced. ..Jewell.. 06/18/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1224 AM CDT Tue Jun 18 2024 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE SOUTHERN HIGH PLAINS...FROM PARTS OF IOWA INTO SOUTHERN WISCONSIN...AND OVER FAR SOUTHERN TEXAS... ...SUMMARY... Locally strong gusts may occur with storms over the southern High Plains, and from parts of Iowa into southern Wisconsin. A brief tornado cannot be ruled out over far southern Texas late Wednesday and Wednesday night in association with Potential Tropical Cyclone 1. ...Synopsis... The tail end of an upper trough will sweep across the northern Plains and upper MS Valley during the day, with primary speed max well into Ontario. Meanwhile, a strong upper ridge will extend from the OH Valley into the Northeast, with rising heights and subsidence developing over the Plains and south of the departing wave. At the surface, a cold front will decelerate into WI, becoming stationary during the evening westward into KS and toward northeast NM. While a moist air mass will exist ahead of this front, warming temperatures aloft and weakening lift will minimize severe potential across those areas. However, easterly upslope flow may result in a few strong storms into NM. Farther south, a very moist air mass will push west across the western Gulf of Mexico with upper 70s F dewpoints across southern TX. Overall wind fields are likely to increase as Potential Tropical Cyclone 1 develops, and possibly becomes a TS per NHC guidance. ...From southern WI to northeast NM... Areas of thunderstorms are likely to be ongoing Wednesday morning over parts of the central Plains, potentially producing strong outflow winds. This convection is expected to weaken during the day, with a rejuvenation along portions of the boundary during the afternoon. The most likely areas for isolated severe gusts appear to be over the IA to WI/IL portion of the boundary in closer proximity to the exiting upper wave, and in the upslope region over eastern NM. In both areas, neither shear nor instability will be particularly strong, but the front should provide a focus for development in a marginally unstable environment. In addition to gusty winds, cells over northeast NM into the OK/TX Panhandles may produce marginally severe hail as veering winds with height favor cellular storm mode. ...Far southern TX... Substantial convection with the potential tropical cyclone will move westward from the Gulf of Mexico and into southern TX, providing heavy rainfall and increasing winds. Official NHC guidance brings the system to tropical storm strength prior to landfall over Mexico early Thursday morning, which will maintain moist easterly winds across TX. Forecast soundings from various models depict upper 70s F dewpoints will favor sufficient SBCAPE for a few strong storms given 30-50 kt winds through the lowest few km AGL, veering with height. The combination of a very moist air mass with potentially strong low-level shear may favor a minimal tornado risk over the region, and low tornado probabilities have been introduced. ..Jewell.. 06/18/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1224 AM CDT Tue Jun 18 2024 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE SOUTHERN HIGH PLAINS...FROM PARTS OF IOWA INTO SOUTHERN WISCONSIN...AND OVER FAR SOUTHERN TEXAS... ...SUMMARY... Locally strong gusts may occur with storms over the southern High Plains, and from parts of Iowa into southern Wisconsin. A brief tornado cannot be ruled out over far southern Texas late Wednesday and Wednesday night in association with Potential Tropical Cyclone 1. ...Synopsis... The tail end of an upper trough will sweep across the northern Plains and upper MS Valley during the day, with primary speed max well into Ontario. Meanwhile, a strong upper ridge will extend from the OH Valley into the Northeast, with rising heights and subsidence developing over the Plains and south of the departing wave. At the surface, a cold front will decelerate into WI, becoming stationary during the evening westward into KS and toward northeast NM. While a moist air mass will exist ahead of this front, warming temperatures aloft and weakening lift will minimize severe potential across those areas. However, easterly upslope flow may result in a few strong storms into NM. Farther south, a very moist air mass will push west across the western Gulf of Mexico with upper 70s F dewpoints across southern TX. Overall wind fields are likely to increase as Potential Tropical Cyclone 1 develops, and possibly becomes a TS per NHC guidance. ...From southern WI to northeast NM... Areas of thunderstorms are likely to be ongoing Wednesday morning over parts of the central Plains, potentially producing strong outflow winds. This convection is expected to weaken during the day, with a rejuvenation along portions of the boundary during the afternoon. The most likely areas for isolated severe gusts appear to be over the IA to WI/IL portion of the boundary in closer proximity to the exiting upper wave, and in the upslope region over eastern NM. In both areas, neither shear nor instability will be particularly strong, but the front should provide a focus for development in a marginally unstable environment. In addition to gusty winds, cells over northeast NM into the OK/TX Panhandles may produce marginally severe hail as veering winds with height favor cellular storm mode. ...Far southern TX... Substantial convection with the potential tropical cyclone will move westward from the Gulf of Mexico and into southern TX, providing heavy rainfall and increasing winds. Official NHC guidance brings the system to tropical storm strength prior to landfall over Mexico early Thursday morning, which will maintain moist easterly winds across TX. Forecast soundings from various models depict upper 70s F dewpoints will favor sufficient SBCAPE for a few strong storms given 30-50 kt winds through the lowest few km AGL, veering with height. The combination of a very moist air mass with potentially strong low-level shear may favor a minimal tornado risk over the region, and low tornado probabilities have been introduced. ..Jewell.. 06/18/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1224 AM CDT Tue Jun 18 2024 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE SOUTHERN HIGH PLAINS...FROM PARTS OF IOWA INTO SOUTHERN WISCONSIN...AND OVER FAR SOUTHERN TEXAS... ...SUMMARY... Locally strong gusts may occur with storms over the southern High Plains, and from parts of Iowa into southern Wisconsin. A brief tornado cannot be ruled out over far southern Texas late Wednesday and Wednesday night in association with Potential Tropical Cyclone 1. ...Synopsis... The tail end of an upper trough will sweep across the northern Plains and upper MS Valley during the day, with primary speed max well into Ontario. Meanwhile, a strong upper ridge will extend from the OH Valley into the Northeast, with rising heights and subsidence developing over the Plains and south of the departing wave. At the surface, a cold front will decelerate into WI, becoming stationary during the evening westward into KS and toward northeast NM. While a moist air mass will exist ahead of this front, warming temperatures aloft and weakening lift will minimize severe potential across those areas. However, easterly upslope flow may result in a few strong storms into NM. Farther south, a very moist air mass will push west across the western Gulf of Mexico with upper 70s F dewpoints across southern TX. Overall wind fields are likely to increase as Potential Tropical Cyclone 1 develops, and possibly becomes a TS per NHC guidance. ...From southern WI to northeast NM... Areas of thunderstorms are likely to be ongoing Wednesday morning over parts of the central Plains, potentially producing strong outflow winds. This convection is expected to weaken during the day, with a rejuvenation along portions of the boundary during the afternoon. The most likely areas for isolated severe gusts appear to be over the IA to WI/IL portion of the boundary in closer proximity to the exiting upper wave, and in the upslope region over eastern NM. In both areas, neither shear nor instability will be particularly strong, but the front should provide a focus for development in a marginally unstable environment. In addition to gusty winds, cells over northeast NM into the OK/TX Panhandles may produce marginally severe hail as veering winds with height favor cellular storm mode. ...Far southern TX... Substantial convection with the potential tropical cyclone will move westward from the Gulf of Mexico and into southern TX, providing heavy rainfall and increasing winds. Official NHC guidance brings the system to tropical storm strength prior to landfall over Mexico early Thursday morning, which will maintain moist easterly winds across TX. Forecast soundings from various models depict upper 70s F dewpoints will favor sufficient SBCAPE for a few strong storms given 30-50 kt winds through the lowest few km AGL, veering with height. The combination of a very moist air mass with potentially strong low-level shear may favor a minimal tornado risk over the region, and low tornado probabilities have been introduced. ..Jewell.. 06/18/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1224 AM CDT Tue Jun 18 2024 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE SOUTHERN HIGH PLAINS...FROM PARTS OF IOWA INTO SOUTHERN WISCONSIN...AND OVER FAR SOUTHERN TEXAS... ...SUMMARY... Locally strong gusts may occur with storms over the southern High Plains, and from parts of Iowa into southern Wisconsin. A brief tornado cannot be ruled out over far southern Texas late Wednesday and Wednesday night in association with Potential Tropical Cyclone 1. ...Synopsis... The tail end of an upper trough will sweep across the northern Plains and upper MS Valley during the day, with primary speed max well into Ontario. Meanwhile, a strong upper ridge will extend from the OH Valley into the Northeast, with rising heights and subsidence developing over the Plains and south of the departing wave. At the surface, a cold front will decelerate into WI, becoming stationary during the evening westward into KS and toward northeast NM. While a moist air mass will exist ahead of this front, warming temperatures aloft and weakening lift will minimize severe potential across those areas. However, easterly upslope flow may result in a few strong storms into NM. Farther south, a very moist air mass will push west across the western Gulf of Mexico with upper 70s F dewpoints across southern TX. Overall wind fields are likely to increase as Potential Tropical Cyclone 1 develops, and possibly becomes a TS per NHC guidance. ...From southern WI to northeast NM... Areas of thunderstorms are likely to be ongoing Wednesday morning over parts of the central Plains, potentially producing strong outflow winds. This convection is expected to weaken during the day, with a rejuvenation along portions of the boundary during the afternoon. The most likely areas for isolated severe gusts appear to be over the IA to WI/IL portion of the boundary in closer proximity to the exiting upper wave, and in the upslope region over eastern NM. In both areas, neither shear nor instability will be particularly strong, but the front should provide a focus for development in a marginally unstable environment. In addition to gusty winds, cells over northeast NM into the OK/TX Panhandles may produce marginally severe hail as veering winds with height favor cellular storm mode. ...Far southern TX... Substantial convection with the potential tropical cyclone will move westward from the Gulf of Mexico and into southern TX, providing heavy rainfall and increasing winds. Official NHC guidance brings the system to tropical storm strength prior to landfall over Mexico early Thursday morning, which will maintain moist easterly winds across TX. Forecast soundings from various models depict upper 70s F dewpoints will favor sufficient SBCAPE for a few strong storms given 30-50 kt winds through the lowest few km AGL, veering with height. The combination of a very moist air mass with potentially strong low-level shear may favor a minimal tornado risk over the region, and low tornado probabilities have been introduced. ..Jewell.. 06/18/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1224 AM CDT Tue Jun 18 2024 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE SOUTHERN HIGH PLAINS...FROM PARTS OF IOWA INTO SOUTHERN WISCONSIN...AND OVER FAR SOUTHERN TEXAS... ...SUMMARY... Locally strong gusts may occur with storms over the southern High Plains, and from parts of Iowa into southern Wisconsin. A brief tornado cannot be ruled out over far southern Texas late Wednesday and Wednesday night in association with Potential Tropical Cyclone 1. ...Synopsis... The tail end of an upper trough will sweep across the northern Plains and upper MS Valley during the day, with primary speed max well into Ontario. Meanwhile, a strong upper ridge will extend from the OH Valley into the Northeast, with rising heights and subsidence developing over the Plains and south of the departing wave. At the surface, a cold front will decelerate into WI, becoming stationary during the evening westward into KS and toward northeast NM. While a moist air mass will exist ahead of this front, warming temperatures aloft and weakening lift will minimize severe potential across those areas. However, easterly upslope flow may result in a few strong storms into NM. Farther south, a very moist air mass will push west across the western Gulf of Mexico with upper 70s F dewpoints across southern TX. Overall wind fields are likely to increase as Potential Tropical Cyclone 1 develops, and possibly becomes a TS per NHC guidance. ...From southern WI to northeast NM... Areas of thunderstorms are likely to be ongoing Wednesday morning over parts of the central Plains, potentially producing strong outflow winds. This convection is expected to weaken during the day, with a rejuvenation along portions of the boundary during the afternoon. The most likely areas for isolated severe gusts appear to be over the IA to WI/IL portion of the boundary in closer proximity to the exiting upper wave, and in the upslope region over eastern NM. In both areas, neither shear nor instability will be particularly strong, but the front should provide a focus for development in a marginally unstable environment. In addition to gusty winds, cells over northeast NM into the OK/TX Panhandles may produce marginally severe hail as veering winds with height favor cellular storm mode. ...Far southern TX... Substantial convection with the potential tropical cyclone will move westward from the Gulf of Mexico and into southern TX, providing heavy rainfall and increasing winds. Official NHC guidance brings the system to tropical storm strength prior to landfall over Mexico early Thursday morning, which will maintain moist easterly winds across TX. Forecast soundings from various models depict upper 70s F dewpoints will favor sufficient SBCAPE for a few strong storms given 30-50 kt winds through the lowest few km AGL, veering with height. The combination of a very moist air mass with potentially strong low-level shear may favor a minimal tornado risk over the region, and low tornado probabilities have been introduced. ..Jewell.. 06/18/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1224 AM CDT Tue Jun 18 2024 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE SOUTHERN HIGH PLAINS...FROM PARTS OF IOWA INTO SOUTHERN WISCONSIN...AND OVER FAR SOUTHERN TEXAS... ...SUMMARY... Locally strong gusts may occur with storms over the southern High Plains, and from parts of Iowa into southern Wisconsin. A brief tornado cannot be ruled out over far southern Texas late Wednesday and Wednesday night in association with Potential Tropical Cyclone 1. ...Synopsis... The tail end of an upper trough will sweep across the northern Plains and upper MS Valley during the day, with primary speed max well into Ontario. Meanwhile, a strong upper ridge will extend from the OH Valley into the Northeast, with rising heights and subsidence developing over the Plains and south of the departing wave. At the surface, a cold front will decelerate into WI, becoming stationary during the evening westward into KS and toward northeast NM. While a moist air mass will exist ahead of this front, warming temperatures aloft and weakening lift will minimize severe potential across those areas. However, easterly upslope flow may result in a few strong storms into NM. Farther south, a very moist air mass will push west across the western Gulf of Mexico with upper 70s F dewpoints across southern TX. Overall wind fields are likely to increase as Potential Tropical Cyclone 1 develops, and possibly becomes a TS per NHC guidance. ...From southern WI to northeast NM... Areas of thunderstorms are likely to be ongoing Wednesday morning over parts of the central Plains, potentially producing strong outflow winds. This convection is expected to weaken during the day, with a rejuvenation along portions of the boundary during the afternoon. The most likely areas for isolated severe gusts appear to be over the IA to WI/IL portion of the boundary in closer proximity to the exiting upper wave, and in the upslope region over eastern NM. In both areas, neither shear nor instability will be particularly strong, but the front should provide a focus for development in a marginally unstable environment. In addition to gusty winds, cells over northeast NM into the OK/TX Panhandles may produce marginally severe hail as veering winds with height favor cellular storm mode. ...Far southern TX... Substantial convection with the potential tropical cyclone will move westward from the Gulf of Mexico and into southern TX, providing heavy rainfall and increasing winds. Official NHC guidance brings the system to tropical storm strength prior to landfall over Mexico early Thursday morning, which will maintain moist easterly winds across TX. Forecast soundings from various models depict upper 70s F dewpoints will favor sufficient SBCAPE for a few strong storms given 30-50 kt winds through the lowest few km AGL, veering with height. The combination of a very moist air mass with potentially strong low-level shear may favor a minimal tornado risk over the region, and low tornado probabilities have been introduced. ..Jewell.. 06/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Jun 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MISSISSIPPI VALLEY TO THE CENTRAL HIGH PLAINS... ...SUMMARY... Scattered strong to severe storms will be possible this afternoon over parts of the Upper Mississippi Valley southwestward into the central High Plains. ...Upper Mississippi Valley to the central High Plains... A pronounced upper trough is currently evident over the northern Rockies. This feature is forecast to eject into the northern High Plains by 19/00z, then across MB/upper Red River region by the end of the period. While weak mid-level height falls will extend along this corridor early, much of the CONUS will actually experience neutral-weak height rises as the eastern US anticyclone dominates and builds west into the OH Valley. This evolution will result in a notable surface low tracking from eastern SD, across northern MN into western ON by mid afternoon. Building surface pressures over the Plains will force a cold front southeast and this boundary will serve as the focus for potentially strong/severe convection later in the day. Early in the period, strong low-level warm advection will prove instrumental in a zone of robust convection across the upper Red River Valley into western ON. As the LLJ lifts northeast in response to the short wave, the majority of elevated convection will progress north of the international border. Of more significance will be convection that develops later in the afternoon along/ahead of the cold front. Latest model guidance suggests modest boundary-layer heating will occur ahead of the wind shift and this should aid buoyancy for potential robust updrafts. Strongest mid-level flow and deep-layer shear will be noted across the upper MS Valley, but adequate shear will extend the length of the front into the central High Plains where a few supercells are expected to develop. The primary risk for organized updrafts will be during the late afternoon/evening hours when instability will be maximized. Large hail and damaging winds are the primary risks. ...Upper Ohio Valley into upstate NY... Water-vapor imagery depicts at least one significant disturbance rotating northeast around the anticyclone. This feature is currently located over IL and should contribute to diurnally-enhanced convection later today. Current trends/model guidance suggest this disturbance will advect into lower MI by 18z, then into southern ON by early evening. Surface heating should contribute to destabilization across the upper OH Valley into upstate NY and isolated-scattered thunderstorms will once again develop. Gusty winds are the primary concern with this weak-modestly sheared activity. ..Darrow/Thornton.. 06/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Jun 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MISSISSIPPI VALLEY TO THE CENTRAL HIGH PLAINS... ...SUMMARY... Scattered strong to severe storms will be possible this afternoon over parts of the Upper Mississippi Valley southwestward into the central High Plains. ...Upper Mississippi Valley to the central High Plains... A pronounced upper trough is currently evident over the northern Rockies. This feature is forecast to eject into the northern High Plains by 19/00z, then across MB/upper Red River region by the end of the period. While weak mid-level height falls will extend along this corridor early, much of the CONUS will actually experience neutral-weak height rises as the eastern US anticyclone dominates and builds west into the OH Valley. This evolution will result in a notable surface low tracking from eastern SD, across northern MN into western ON by mid afternoon. Building surface pressures over the Plains will force a cold front southeast and this boundary will serve as the focus for potentially strong/severe convection later in the day. Early in the period, strong low-level warm advection will prove instrumental in a zone of robust convection across the upper Red River Valley into western ON. As the LLJ lifts northeast in response to the short wave, the majority of elevated convection will progress north of the international border. Of more significance will be convection that develops later in the afternoon along/ahead of the cold front. Latest model guidance suggests modest boundary-layer heating will occur ahead of the wind shift and this should aid buoyancy for potential robust updrafts. Strongest mid-level flow and deep-layer shear will be noted across the upper MS Valley, but adequate shear will extend the length of the front into the central High Plains where a few supercells are expected to develop. The primary risk for organized updrafts will be during the late afternoon/evening hours when instability will be maximized. Large hail and damaging winds are the primary risks. ...Upper Ohio Valley into upstate NY... Water-vapor imagery depicts at least one significant disturbance rotating northeast around the anticyclone. This feature is currently located over IL and should contribute to diurnally-enhanced convection later today. Current trends/model guidance suggest this disturbance will advect into lower MI by 18z, then into southern ON by early evening. Surface heating should contribute to destabilization across the upper OH Valley into upstate NY and isolated-scattered thunderstorms will once again develop. Gusty winds are the primary concern with this weak-modestly sheared activity. ..Darrow/Thornton.. 06/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Jun 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MISSISSIPPI VALLEY TO THE CENTRAL HIGH PLAINS... ...SUMMARY... Scattered strong to severe storms will be possible this afternoon over parts of the Upper Mississippi Valley southwestward into the central High Plains. ...Upper Mississippi Valley to the central High Plains... A pronounced upper trough is currently evident over the northern Rockies. This feature is forecast to eject into the northern High Plains by 19/00z, then across MB/upper Red River region by the end of the period. While weak mid-level height falls will extend along this corridor early, much of the CONUS will actually experience neutral-weak height rises as the eastern US anticyclone dominates and builds west into the OH Valley. This evolution will result in a notable surface low tracking from eastern SD, across northern MN into western ON by mid afternoon. Building surface pressures over the Plains will force a cold front southeast and this boundary will serve as the focus for potentially strong/severe convection later in the day. Early in the period, strong low-level warm advection will prove instrumental in a zone of robust convection across the upper Red River Valley into western ON. As the LLJ lifts northeast in response to the short wave, the majority of elevated convection will progress north of the international border. Of more significance will be convection that develops later in the afternoon along/ahead of the cold front. Latest model guidance suggests modest boundary-layer heating will occur ahead of the wind shift and this should aid buoyancy for potential robust updrafts. Strongest mid-level flow and deep-layer shear will be noted across the upper MS Valley, but adequate shear will extend the length of the front into the central High Plains where a few supercells are expected to develop. The primary risk for organized updrafts will be during the late afternoon/evening hours when instability will be maximized. Large hail and damaging winds are the primary risks. ...Upper Ohio Valley into upstate NY... Water-vapor imagery depicts at least one significant disturbance rotating northeast around the anticyclone. This feature is currently located over IL and should contribute to diurnally-enhanced convection later today. Current trends/model guidance suggest this disturbance will advect into lower MI by 18z, then into southern ON by early evening. Surface heating should contribute to destabilization across the upper OH Valley into upstate NY and isolated-scattered thunderstorms will once again develop. Gusty winds are the primary concern with this weak-modestly sheared activity. ..Darrow/Thornton.. 06/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Jun 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MISSISSIPPI VALLEY TO THE CENTRAL HIGH PLAINS... ...SUMMARY... Scattered strong to severe storms will be possible this afternoon over parts of the Upper Mississippi Valley southwestward into the central High Plains. ...Upper Mississippi Valley to the central High Plains... A pronounced upper trough is currently evident over the northern Rockies. This feature is forecast to eject into the northern High Plains by 19/00z, then across MB/upper Red River region by the end of the period. While weak mid-level height falls will extend along this corridor early, much of the CONUS will actually experience neutral-weak height rises as the eastern US anticyclone dominates and builds west into the OH Valley. This evolution will result in a notable surface low tracking from eastern SD, across northern MN into western ON by mid afternoon. Building surface pressures over the Plains will force a cold front southeast and this boundary will serve as the focus for potentially strong/severe convection later in the day. Early in the period, strong low-level warm advection will prove instrumental in a zone of robust convection across the upper Red River Valley into western ON. As the LLJ lifts northeast in response to the short wave, the majority of elevated convection will progress north of the international border. Of more significance will be convection that develops later in the afternoon along/ahead of the cold front. Latest model guidance suggests modest boundary-layer heating will occur ahead of the wind shift and this should aid buoyancy for potential robust updrafts. Strongest mid-level flow and deep-layer shear will be noted across the upper MS Valley, but adequate shear will extend the length of the front into the central High Plains where a few supercells are expected to develop. The primary risk for organized updrafts will be during the late afternoon/evening hours when instability will be maximized. Large hail and damaging winds are the primary risks. ...Upper Ohio Valley into upstate NY... Water-vapor imagery depicts at least one significant disturbance rotating northeast around the anticyclone. This feature is currently located over IL and should contribute to diurnally-enhanced convection later today. Current trends/model guidance suggest this disturbance will advect into lower MI by 18z, then into southern ON by early evening. Surface heating should contribute to destabilization across the upper OH Valley into upstate NY and isolated-scattered thunderstorms will once again develop. Gusty winds are the primary concern with this weak-modestly sheared activity. ..Darrow/Thornton.. 06/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Jun 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MISSISSIPPI VALLEY TO THE CENTRAL HIGH PLAINS... ...SUMMARY... Scattered strong to severe storms will be possible this afternoon over parts of the Upper Mississippi Valley southwestward into the central High Plains. ...Upper Mississippi Valley to the central High Plains... A pronounced upper trough is currently evident over the northern Rockies. This feature is forecast to eject into the northern High Plains by 19/00z, then across MB/upper Red River region by the end of the period. While weak mid-level height falls will extend along this corridor early, much of the CONUS will actually experience neutral-weak height rises as the eastern US anticyclone dominates and builds west into the OH Valley. This evolution will result in a notable surface low tracking from eastern SD, across northern MN into western ON by mid afternoon. Building surface pressures over the Plains will force a cold front southeast and this boundary will serve as the focus for potentially strong/severe convection later in the day. Early in the period, strong low-level warm advection will prove instrumental in a zone of robust convection across the upper Red River Valley into western ON. As the LLJ lifts northeast in response to the short wave, the majority of elevated convection will progress north of the international border. Of more significance will be convection that develops later in the afternoon along/ahead of the cold front. Latest model guidance suggests modest boundary-layer heating will occur ahead of the wind shift and this should aid buoyancy for potential robust updrafts. Strongest mid-level flow and deep-layer shear will be noted across the upper MS Valley, but adequate shear will extend the length of the front into the central High Plains where a few supercells are expected to develop. The primary risk for organized updrafts will be during the late afternoon/evening hours when instability will be maximized. Large hail and damaging winds are the primary risks. ...Upper Ohio Valley into upstate NY... Water-vapor imagery depicts at least one significant disturbance rotating northeast around the anticyclone. This feature is currently located over IL and should contribute to diurnally-enhanced convection later today. Current trends/model guidance suggest this disturbance will advect into lower MI by 18z, then into southern ON by early evening. Surface heating should contribute to destabilization across the upper OH Valley into upstate NY and isolated-scattered thunderstorms will once again develop. Gusty winds are the primary concern with this weak-modestly sheared activity. ..Darrow/Thornton.. 06/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Jun 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MISSISSIPPI VALLEY TO THE CENTRAL HIGH PLAINS... ...SUMMARY... Scattered strong to severe storms will be possible this afternoon over parts of the Upper Mississippi Valley southwestward into the central High Plains. ...Upper Mississippi Valley to the central High Plains... A pronounced upper trough is currently evident over the northern Rockies. This feature is forecast to eject into the northern High Plains by 19/00z, then across MB/upper Red River region by the end of the period. While weak mid-level height falls will extend along this corridor early, much of the CONUS will actually experience neutral-weak height rises as the eastern US anticyclone dominates and builds west into the OH Valley. This evolution will result in a notable surface low tracking from eastern SD, across northern MN into western ON by mid afternoon. Building surface pressures over the Plains will force a cold front southeast and this boundary will serve as the focus for potentially strong/severe convection later in the day. Early in the period, strong low-level warm advection will prove instrumental in a zone of robust convection across the upper Red River Valley into western ON. As the LLJ lifts northeast in response to the short wave, the majority of elevated convection will progress north of the international border. Of more significance will be convection that develops later in the afternoon along/ahead of the cold front. Latest model guidance suggests modest boundary-layer heating will occur ahead of the wind shift and this should aid buoyancy for potential robust updrafts. Strongest mid-level flow and deep-layer shear will be noted across the upper MS Valley, but adequate shear will extend the length of the front into the central High Plains where a few supercells are expected to develop. The primary risk for organized updrafts will be during the late afternoon/evening hours when instability will be maximized. Large hail and damaging winds are the primary risks. ...Upper Ohio Valley into upstate NY... Water-vapor imagery depicts at least one significant disturbance rotating northeast around the anticyclone. This feature is currently located over IL and should contribute to diurnally-enhanced convection later today. Current trends/model guidance suggest this disturbance will advect into lower MI by 18z, then into southern ON by early evening. Surface heating should contribute to destabilization across the upper OH Valley into upstate NY and isolated-scattered thunderstorms will once again develop. Gusty winds are the primary concern with this weak-modestly sheared activity. ..Darrow/Thornton.. 06/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Jun 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MISSISSIPPI VALLEY TO THE CENTRAL HIGH PLAINS... ...SUMMARY... Scattered strong to severe storms will be possible this afternoon over parts of the Upper Mississippi Valley southwestward into the central High Plains. ...Upper Mississippi Valley to the central High Plains... A pronounced upper trough is currently evident over the northern Rockies. This feature is forecast to eject into the northern High Plains by 19/00z, then across MB/upper Red River region by the end of the period. While weak mid-level height falls will extend along this corridor early, much of the CONUS will actually experience neutral-weak height rises as the eastern US anticyclone dominates and builds west into the OH Valley. This evolution will result in a notable surface low tracking from eastern SD, across northern MN into western ON by mid afternoon. Building surface pressures over the Plains will force a cold front southeast and this boundary will serve as the focus for potentially strong/severe convection later in the day. Early in the period, strong low-level warm advection will prove instrumental in a zone of robust convection across the upper Red River Valley into western ON. As the LLJ lifts northeast in response to the short wave, the majority of elevated convection will progress north of the international border. Of more significance will be convection that develops later in the afternoon along/ahead of the cold front. Latest model guidance suggests modest boundary-layer heating will occur ahead of the wind shift and this should aid buoyancy for potential robust updrafts. Strongest mid-level flow and deep-layer shear will be noted across the upper MS Valley, but adequate shear will extend the length of the front into the central High Plains where a few supercells are expected to develop. The primary risk for organized updrafts will be during the late afternoon/evening hours when instability will be maximized. Large hail and damaging winds are the primary risks. ...Upper Ohio Valley into upstate NY... Water-vapor imagery depicts at least one significant disturbance rotating northeast around the anticyclone. This feature is currently located over IL and should contribute to diurnally-enhanced convection later today. Current trends/model guidance suggest this disturbance will advect into lower MI by 18z, then into southern ON by early evening. Surface heating should contribute to destabilization across the upper OH Valley into upstate NY and isolated-scattered thunderstorms will once again develop. Gusty winds are the primary concern with this weak-modestly sheared activity. ..Darrow/Thornton.. 06/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Jun 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MISSISSIPPI VALLEY TO THE CENTRAL HIGH PLAINS... ...SUMMARY... Scattered strong to severe storms will be possible this afternoon over parts of the Upper Mississippi Valley southwestward into the central High Plains. ...Upper Mississippi Valley to the central High Plains... A pronounced upper trough is currently evident over the northern Rockies. This feature is forecast to eject into the northern High Plains by 19/00z, then across MB/upper Red River region by the end of the period. While weak mid-level height falls will extend along this corridor early, much of the CONUS will actually experience neutral-weak height rises as the eastern US anticyclone dominates and builds west into the OH Valley. This evolution will result in a notable surface low tracking from eastern SD, across northern MN into western ON by mid afternoon. Building surface pressures over the Plains will force a cold front southeast and this boundary will serve as the focus for potentially strong/severe convection later in the day. Early in the period, strong low-level warm advection will prove instrumental in a zone of robust convection across the upper Red River Valley into western ON. As the LLJ lifts northeast in response to the short wave, the majority of elevated convection will progress north of the international border. Of more significance will be convection that develops later in the afternoon along/ahead of the cold front. Latest model guidance suggests modest boundary-layer heating will occur ahead of the wind shift and this should aid buoyancy for potential robust updrafts. Strongest mid-level flow and deep-layer shear will be noted across the upper MS Valley, but adequate shear will extend the length of the front into the central High Plains where a few supercells are expected to develop. The primary risk for organized updrafts will be during the late afternoon/evening hours when instability will be maximized. Large hail and damaging winds are the primary risks. ...Upper Ohio Valley into upstate NY... Water-vapor imagery depicts at least one significant disturbance rotating northeast around the anticyclone. This feature is currently located over IL and should contribute to diurnally-enhanced convection later today. Current trends/model guidance suggest this disturbance will advect into lower MI by 18z, then into southern ON by early evening. Surface heating should contribute to destabilization across the upper OH Valley into upstate NY and isolated-scattered thunderstorms will once again develop. Gusty winds are the primary concern with this weak-modestly sheared activity. ..Darrow/Thornton.. 06/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Jun 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MISSISSIPPI VALLEY TO THE CENTRAL HIGH PLAINS... ...SUMMARY... Scattered strong to severe storms will be possible this afternoon over parts of the Upper Mississippi Valley southwestward into the central High Plains. ...Upper Mississippi Valley to the central High Plains... A pronounced upper trough is currently evident over the northern Rockies. This feature is forecast to eject into the northern High Plains by 19/00z, then across MB/upper Red River region by the end of the period. While weak mid-level height falls will extend along this corridor early, much of the CONUS will actually experience neutral-weak height rises as the eastern US anticyclone dominates and builds west into the OH Valley. This evolution will result in a notable surface low tracking from eastern SD, across northern MN into western ON by mid afternoon. Building surface pressures over the Plains will force a cold front southeast and this boundary will serve as the focus for potentially strong/severe convection later in the day. Early in the period, strong low-level warm advection will prove instrumental in a zone of robust convection across the upper Red River Valley into western ON. As the LLJ lifts northeast in response to the short wave, the majority of elevated convection will progress north of the international border. Of more significance will be convection that develops later in the afternoon along/ahead of the cold front. Latest model guidance suggests modest boundary-layer heating will occur ahead of the wind shift and this should aid buoyancy for potential robust updrafts. Strongest mid-level flow and deep-layer shear will be noted across the upper MS Valley, but adequate shear will extend the length of the front into the central High Plains where a few supercells are expected to develop. The primary risk for organized updrafts will be during the late afternoon/evening hours when instability will be maximized. Large hail and damaging winds are the primary risks. ...Upper Ohio Valley into upstate NY... Water-vapor imagery depicts at least one significant disturbance rotating northeast around the anticyclone. This feature is currently located over IL and should contribute to diurnally-enhanced convection later today. Current trends/model guidance suggest this disturbance will advect into lower MI by 18z, then into southern ON by early evening. Surface heating should contribute to destabilization across the upper OH Valley into upstate NY and isolated-scattered thunderstorms will once again develop. Gusty winds are the primary concern with this weak-modestly sheared activity. ..Darrow/Thornton.. 06/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Jun 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MISSISSIPPI VALLEY TO THE CENTRAL HIGH PLAINS... ...SUMMARY... Scattered strong to severe storms will be possible this afternoon over parts of the Upper Mississippi Valley southwestward into the central High Plains. ...Upper Mississippi Valley to the central High Plains... A pronounced upper trough is currently evident over the northern Rockies. This feature is forecast to eject into the northern High Plains by 19/00z, then across MB/upper Red River region by the end of the period. While weak mid-level height falls will extend along this corridor early, much of the CONUS will actually experience neutral-weak height rises as the eastern US anticyclone dominates and builds west into the OH Valley. This evolution will result in a notable surface low tracking from eastern SD, across northern MN into western ON by mid afternoon. Building surface pressures over the Plains will force a cold front southeast and this boundary will serve as the focus for potentially strong/severe convection later in the day. Early in the period, strong low-level warm advection will prove instrumental in a zone of robust convection across the upper Red River Valley into western ON. As the LLJ lifts northeast in response to the short wave, the majority of elevated convection will progress north of the international border. Of more significance will be convection that develops later in the afternoon along/ahead of the cold front. Latest model guidance suggests modest boundary-layer heating will occur ahead of the wind shift and this should aid buoyancy for potential robust updrafts. Strongest mid-level flow and deep-layer shear will be noted across the upper MS Valley, but adequate shear will extend the length of the front into the central High Plains where a few supercells are expected to develop. The primary risk for organized updrafts will be during the late afternoon/evening hours when instability will be maximized. Large hail and damaging winds are the primary risks. ...Upper Ohio Valley into upstate NY... Water-vapor imagery depicts at least one significant disturbance rotating northeast around the anticyclone. This feature is currently located over IL and should contribute to diurnally-enhanced convection later today. Current trends/model guidance suggest this disturbance will advect into lower MI by 18z, then into southern ON by early evening. Surface heating should contribute to destabilization across the upper OH Valley into upstate NY and isolated-scattered thunderstorms will once again develop. Gusty winds are the primary concern with this weak-modestly sheared activity. ..Darrow/Thornton.. 06/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Jun 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MISSISSIPPI VALLEY TO THE CENTRAL HIGH PLAINS... ...SUMMARY... Scattered strong to severe storms will be possible this afternoon over parts of the Upper Mississippi Valley southwestward into the central High Plains. ...Upper Mississippi Valley to the central High Plains... A pronounced upper trough is currently evident over the northern Rockies. This feature is forecast to eject into the northern High Plains by 19/00z, then across MB/upper Red River region by the end of the period. While weak mid-level height falls will extend along this corridor early, much of the CONUS will actually experience neutral-weak height rises as the eastern US anticyclone dominates and builds west into the OH Valley. This evolution will result in a notable surface low tracking from eastern SD, across northern MN into western ON by mid afternoon. Building surface pressures over the Plains will force a cold front southeast and this boundary will serve as the focus for potentially strong/severe convection later in the day. Early in the period, strong low-level warm advection will prove instrumental in a zone of robust convection across the upper Red River Valley into western ON. As the LLJ lifts northeast in response to the short wave, the majority of elevated convection will progress north of the international border. Of more significance will be convection that develops later in the afternoon along/ahead of the cold front. Latest model guidance suggests modest boundary-layer heating will occur ahead of the wind shift and this should aid buoyancy for potential robust updrafts. Strongest mid-level flow and deep-layer shear will be noted across the upper MS Valley, but adequate shear will extend the length of the front into the central High Plains where a few supercells are expected to develop. The primary risk for organized updrafts will be during the late afternoon/evening hours when instability will be maximized. Large hail and damaging winds are the primary risks. ...Upper Ohio Valley into upstate NY... Water-vapor imagery depicts at least one significant disturbance rotating northeast around the anticyclone. This feature is currently located over IL and should contribute to diurnally-enhanced convection later today. Current trends/model guidance suggest this disturbance will advect into lower MI by 18z, then into southern ON by early evening. Surface heating should contribute to destabilization across the upper OH Valley into upstate NY and isolated-scattered thunderstorms will once again develop. Gusty winds are the primary concern with this weak-modestly sheared activity. ..Darrow/Thornton.. 06/18/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Jun 18 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MISSISSIPPI VALLEY TO THE CENTRAL HIGH PLAINS... ...SUMMARY... Scattered strong to severe storms will be possible this afternoon over parts of the Upper Mississippi Valley southwestward into the central High Plains. ...Upper Mississippi Valley to the central High Plains... A pronounced upper trough is currently evident over the northern Rockies. This feature is forecast to eject into the northern High Plains by 19/00z, then across MB/upper Red River region by the end of the period. While weak mid-level height falls will extend along this corridor early, much of the CONUS will actually experience neutral-weak height rises as the eastern US anticyclone dominates and builds west into the OH Valley. This evolution will result in a notable surface low tracking from eastern SD, across northern MN into western ON by mid afternoon. Building surface pressures over the Plains will force a cold front southeast and this boundary will serve as the focus for potentially strong/severe convection later in the day. Early in the period, strong low-level warm advection will prove instrumental in a zone of robust convection across the upper Red River Valley into western ON. As the LLJ lifts northeast in response to the short wave, the majority of elevated convection will progress north of the international border. Of more significance will be convection that develops later in the afternoon along/ahead of the cold front. Latest model guidance suggests modest boundary-layer heating will occur ahead of the wind shift and this should aid buoyancy for potential robust updrafts. Strongest mid-level flow and deep-layer shear will be noted across the upper MS Valley, but adequate shear will extend the length of the front into the central High Plains where a few supercells are expected to develop. The primary risk for organized updrafts will be during the late afternoon/evening hours when instability will be maximized. Large hail and damaging winds are the primary risks. ...Upper Ohio Valley into upstate NY... Water-vapor imagery depicts at least one significant disturbance rotating northeast around the anticyclone. This feature is currently located over IL and should contribute to diurnally-enhanced convection later today. Current trends/model guidance suggest this disturbance will advect into lower MI by 18z, then into southern ON by early evening. Surface heating should contribute to destabilization across the upper OH Valley into upstate NY and isolated-scattered thunderstorms will once again develop. Gusty winds are the primary concern with this weak-modestly sheared activity. ..Darrow/Thornton.. 06/18/2024 Read more

WW 0431 Status Updates
STATUS REPORT ON WW 431 SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 40 NE RAP TO 35 ESE BIS TO 40 NNW JMS. ..LEITMAN..06/18/24 ATTN...WFO...FGF...BIS...ABR...UNR... STATUS REPORT FOR WS 431 SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS NDC003-021-027-029-031-039-043-045-047-051-093-180640- ND . NORTH DAKOTA COUNTIES INCLUDED ARE BARNES DICKEY EDDY EMMONS FOSTER GRIGGS KIDDER LAMOURE LOGAN MCINTOSH STUTSMAN SDC013-021-031-041-045-049-055-065-071-075-089-107-117-119-129- 137-180640- SD . SOUTH DAKOTA COUNTIES INCLUDED ARE BROWN CAMPBELL CORSON DEWEY EDMUNDS FAULK HAAKON HUGHES JACKSON JONES MCPHERSON POTTER STANLEY SULLY WALWORTH ZIEBACH Read more