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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST INTO PORTIONS OF THE MID MISSISSIPPI VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Strong to severe thunderstorms are possible from the Upper Midwest into the Mid Mississippi Valley and Upper Great Lakes region on Monday. Isolated severe thunderstorms are also possible across the central Plains as well as south-central/southeast Arizona. ...Synopsis... Upper ridging is forecast to persist across the southern CONUS on Monday, while upper troughing extends across central Canada. A belt of enhanced, broadly cyclonic upper flow will exist between these two areas, extending across much of the northern CONUS. Several shortwave troughs are expected to progress through this corridor, with the most prominent wave extending from southern Manitoba southward across the Dakotas early Monday. This shortwave is forecast to progress eastward/east-southeastward across the Upper Midwest, Upper Great Lakes, and southern/eastern Ontario. Another shortwave trough, likely augmented by Sunday night's thunderstorms over the Mid MS Valley, is expected to extend from Lower MI into the Middle OH Valley early Monday night. This shortwave is then expected to continue eastward through the Upper OH Valley and Northeast/northern Mid-Atlantic during the day. Lastly, there is some chance another shortwave trough progresses through the northern periphery of the Southwest upper ridging, emerging into the central Plains and continuing eastward in the Mid MS Valley. Guidance varies on the amplitude and speed of this shortwave, which limits forecast confidence on its potential evolution and impacts. The surface pattern will be convoluted by several areas of antecedent convection, particularly from the Upper Midwest into the Mid MS and OH Valleys where storm outflow appears most likely. General expectation is for warm front to extend eastward from a surface low near the SD/NE/IA border intersection along the MN/IA border vicinity into southern WI. This front will likely extend eastward across the northern portions of the OH Valley, but with a more stationary character. A cold front attendant to the Manitoba/Dakotas shortwave is expected push southward across the Dakotas and into NE and southeastward across the Upper Midwest. By 00Z this front will likely extend from a low over northwest Ontario southwestward to another low over north-central KS. ...Upper MS Valley into the Middle OH Valley and Lower MI... Thunderstorms will likely be ongoing ahead of the cold front across the Upper MS Valley early Monday morning. These early storms are expected to be elevated, but should trend towards becoming more surface based as they progress southeastward and the airmass destabilizes. The strength of the buoyancy within the downstream airmass will depend on the evolution of Sunday night's storms, with at least some potential for some cooler and drier conditions. However, consensus among the guidance is for low 70s dewpoints and strong buoyancy during the afternoon. These thermodynamic conditions, coupled with moderate vertical shear, would support strong to severe thunderstorms. All severe hazards would be possible within any more cellular storms, but a linear mode is expected to dominant, with some potential for the development of an organized MCS. Damaging gusts will be the primary risk across this region. ...Upper OH Valley into the northern Mid-Atlantic... Afternoon/early evening thunderstorms are possible from the Upper OH Valley into the Northeast as the modest, convectively augmented shortwave trough interacts with the warm and moist airmass over the region. Shear will likely be modest, mitigating the potential for organized storms. However, moderate buoyancy and steep low-level lapse rates will support to the potential for strong downbursts with the more robust storms. ...Central High Plains into the Central Plains... Some of the guidance, particularly the CAMs, has trended towards more storm development across the central High Plains during the late afternoon/early evening. The modest shortwave trough progressing through the northern periphery of the upper ridge mentioned in the synopsis appears to be the impetus for these storms, providing the large-scale ascent needed for initiation. High cloud bases and steep low-level lapse rates will support strong outflow, with some cold-pool amalgamation and the development of an organized MCS possible. Uncertainty regarding storm coverage and location of greatest severe potential precludes higher probabilities with this outlook. ...South-Central/Southeast AZ... Modest easterly mid-level flow is expected across the region, which will be located on the western periphery of the upper ridge. Afternoon thunderstorm development is anticipated over the high terrain, with storms then moving westward off into lower elevations. A few strong gusts are possible as these storms move into the well-mixed airmass over the lower elevations. ..Mosier.. 07/14/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST INTO PORTIONS OF THE MID MISSISSIPPI VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Strong to severe thunderstorms are possible from the Upper Midwest into the Mid Mississippi Valley and Upper Great Lakes region on Monday. Isolated severe thunderstorms are also possible across the central Plains as well as south-central/southeast Arizona. ...Synopsis... Upper ridging is forecast to persist across the southern CONUS on Monday, while upper troughing extends across central Canada. A belt of enhanced, broadly cyclonic upper flow will exist between these two areas, extending across much of the northern CONUS. Several shortwave troughs are expected to progress through this corridor, with the most prominent wave extending from southern Manitoba southward across the Dakotas early Monday. This shortwave is forecast to progress eastward/east-southeastward across the Upper Midwest, Upper Great Lakes, and southern/eastern Ontario. Another shortwave trough, likely augmented by Sunday night's thunderstorms over the Mid MS Valley, is expected to extend from Lower MI into the Middle OH Valley early Monday night. This shortwave is then expected to continue eastward through the Upper OH Valley and Northeast/northern Mid-Atlantic during the day. Lastly, there is some chance another shortwave trough progresses through the northern periphery of the Southwest upper ridging, emerging into the central Plains and continuing eastward in the Mid MS Valley. Guidance varies on the amplitude and speed of this shortwave, which limits forecast confidence on its potential evolution and impacts. The surface pattern will be convoluted by several areas of antecedent convection, particularly from the Upper Midwest into the Mid MS and OH Valleys where storm outflow appears most likely. General expectation is for warm front to extend eastward from a surface low near the SD/NE/IA border intersection along the MN/IA border vicinity into southern WI. This front will likely extend eastward across the northern portions of the OH Valley, but with a more stationary character. A cold front attendant to the Manitoba/Dakotas shortwave is expected push southward across the Dakotas and into NE and southeastward across the Upper Midwest. By 00Z this front will likely extend from a low over northwest Ontario southwestward to another low over north-central KS. ...Upper MS Valley into the Middle OH Valley and Lower MI... Thunderstorms will likely be ongoing ahead of the cold front across the Upper MS Valley early Monday morning. These early storms are expected to be elevated, but should trend towards becoming more surface based as they progress southeastward and the airmass destabilizes. The strength of the buoyancy within the downstream airmass will depend on the evolution of Sunday night's storms, with at least some potential for some cooler and drier conditions. However, consensus among the guidance is for low 70s dewpoints and strong buoyancy during the afternoon. These thermodynamic conditions, coupled with moderate vertical shear, would support strong to severe thunderstorms. All severe hazards would be possible within any more cellular storms, but a linear mode is expected to dominant, with some potential for the development of an organized MCS. Damaging gusts will be the primary risk across this region. ...Upper OH Valley into the northern Mid-Atlantic... Afternoon/early evening thunderstorms are possible from the Upper OH Valley into the Northeast as the modest, convectively augmented shortwave trough interacts with the warm and moist airmass over the region. Shear will likely be modest, mitigating the potential for organized storms. However, moderate buoyancy and steep low-level lapse rates will support to the potential for strong downbursts with the more robust storms. ...Central High Plains into the Central Plains... Some of the guidance, particularly the CAMs, has trended towards more storm development across the central High Plains during the late afternoon/early evening. The modest shortwave trough progressing through the northern periphery of the upper ridge mentioned in the synopsis appears to be the impetus for these storms, providing the large-scale ascent needed for initiation. High cloud bases and steep low-level lapse rates will support strong outflow, with some cold-pool amalgamation and the development of an organized MCS possible. Uncertainty regarding storm coverage and location of greatest severe potential precludes higher probabilities with this outlook. ...South-Central/Southeast AZ... Modest easterly mid-level flow is expected across the region, which will be located on the western periphery of the upper ridge. Afternoon thunderstorm development is anticipated over the high terrain, with storms then moving westward off into lower elevations. A few strong gusts are possible as these storms move into the well-mixed airmass over the lower elevations. ..Mosier.. 07/14/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST INTO PORTIONS OF THE MID MISSISSIPPI VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Strong to severe thunderstorms are possible from the Upper Midwest into the Mid Mississippi Valley and Upper Great Lakes region on Monday. Isolated severe thunderstorms are also possible across the central Plains as well as south-central/southeast Arizona. ...Synopsis... Upper ridging is forecast to persist across the southern CONUS on Monday, while upper troughing extends across central Canada. A belt of enhanced, broadly cyclonic upper flow will exist between these two areas, extending across much of the northern CONUS. Several shortwave troughs are expected to progress through this corridor, with the most prominent wave extending from southern Manitoba southward across the Dakotas early Monday. This shortwave is forecast to progress eastward/east-southeastward across the Upper Midwest, Upper Great Lakes, and southern/eastern Ontario. Another shortwave trough, likely augmented by Sunday night's thunderstorms over the Mid MS Valley, is expected to extend from Lower MI into the Middle OH Valley early Monday night. This shortwave is then expected to continue eastward through the Upper OH Valley and Northeast/northern Mid-Atlantic during the day. Lastly, there is some chance another shortwave trough progresses through the northern periphery of the Southwest upper ridging, emerging into the central Plains and continuing eastward in the Mid MS Valley. Guidance varies on the amplitude and speed of this shortwave, which limits forecast confidence on its potential evolution and impacts. The surface pattern will be convoluted by several areas of antecedent convection, particularly from the Upper Midwest into the Mid MS and OH Valleys where storm outflow appears most likely. General expectation is for warm front to extend eastward from a surface low near the SD/NE/IA border intersection along the MN/IA border vicinity into southern WI. This front will likely extend eastward across the northern portions of the OH Valley, but with a more stationary character. A cold front attendant to the Manitoba/Dakotas shortwave is expected push southward across the Dakotas and into NE and southeastward across the Upper Midwest. By 00Z this front will likely extend from a low over northwest Ontario southwestward to another low over north-central KS. ...Upper MS Valley into the Middle OH Valley and Lower MI... Thunderstorms will likely be ongoing ahead of the cold front across the Upper MS Valley early Monday morning. These early storms are expected to be elevated, but should trend towards becoming more surface based as they progress southeastward and the airmass destabilizes. The strength of the buoyancy within the downstream airmass will depend on the evolution of Sunday night's storms, with at least some potential for some cooler and drier conditions. However, consensus among the guidance is for low 70s dewpoints and strong buoyancy during the afternoon. These thermodynamic conditions, coupled with moderate vertical shear, would support strong to severe thunderstorms. All severe hazards would be possible within any more cellular storms, but a linear mode is expected to dominant, with some potential for the development of an organized MCS. Damaging gusts will be the primary risk across this region. ...Upper OH Valley into the northern Mid-Atlantic... Afternoon/early evening thunderstorms are possible from the Upper OH Valley into the Northeast as the modest, convectively augmented shortwave trough interacts with the warm and moist airmass over the region. Shear will likely be modest, mitigating the potential for organized storms. However, moderate buoyancy and steep low-level lapse rates will support to the potential for strong downbursts with the more robust storms. ...Central High Plains into the Central Plains... Some of the guidance, particularly the CAMs, has trended towards more storm development across the central High Plains during the late afternoon/early evening. The modest shortwave trough progressing through the northern periphery of the upper ridge mentioned in the synopsis appears to be the impetus for these storms, providing the large-scale ascent needed for initiation. High cloud bases and steep low-level lapse rates will support strong outflow, with some cold-pool amalgamation and the development of an organized MCS possible. Uncertainty regarding storm coverage and location of greatest severe potential precludes higher probabilities with this outlook. ...South-Central/Southeast AZ... Modest easterly mid-level flow is expected across the region, which will be located on the western periphery of the upper ridge. Afternoon thunderstorm development is anticipated over the high terrain, with storms then moving westward off into lower elevations. A few strong gusts are possible as these storms move into the well-mixed airmass over the lower elevations. ..Mosier.. 07/14/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST INTO PORTIONS OF THE MID MISSISSIPPI VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Strong to severe thunderstorms are possible from the Upper Midwest into the Mid Mississippi Valley and Upper Great Lakes region on Monday. Isolated severe thunderstorms are also possible across the central Plains as well as south-central/southeast Arizona. ...Synopsis... Upper ridging is forecast to persist across the southern CONUS on Monday, while upper troughing extends across central Canada. A belt of enhanced, broadly cyclonic upper flow will exist between these two areas, extending across much of the northern CONUS. Several shortwave troughs are expected to progress through this corridor, with the most prominent wave extending from southern Manitoba southward across the Dakotas early Monday. This shortwave is forecast to progress eastward/east-southeastward across the Upper Midwest, Upper Great Lakes, and southern/eastern Ontario. Another shortwave trough, likely augmented by Sunday night's thunderstorms over the Mid MS Valley, is expected to extend from Lower MI into the Middle OH Valley early Monday night. This shortwave is then expected to continue eastward through the Upper OH Valley and Northeast/northern Mid-Atlantic during the day. Lastly, there is some chance another shortwave trough progresses through the northern periphery of the Southwest upper ridging, emerging into the central Plains and continuing eastward in the Mid MS Valley. Guidance varies on the amplitude and speed of this shortwave, which limits forecast confidence on its potential evolution and impacts. The surface pattern will be convoluted by several areas of antecedent convection, particularly from the Upper Midwest into the Mid MS and OH Valleys where storm outflow appears most likely. General expectation is for warm front to extend eastward from a surface low near the SD/NE/IA border intersection along the MN/IA border vicinity into southern WI. This front will likely extend eastward across the northern portions of the OH Valley, but with a more stationary character. A cold front attendant to the Manitoba/Dakotas shortwave is expected push southward across the Dakotas and into NE and southeastward across the Upper Midwest. By 00Z this front will likely extend from a low over northwest Ontario southwestward to another low over north-central KS. ...Upper MS Valley into the Middle OH Valley and Lower MI... Thunderstorms will likely be ongoing ahead of the cold front across the Upper MS Valley early Monday morning. These early storms are expected to be elevated, but should trend towards becoming more surface based as they progress southeastward and the airmass destabilizes. The strength of the buoyancy within the downstream airmass will depend on the evolution of Sunday night's storms, with at least some potential for some cooler and drier conditions. However, consensus among the guidance is for low 70s dewpoints and strong buoyancy during the afternoon. These thermodynamic conditions, coupled with moderate vertical shear, would support strong to severe thunderstorms. All severe hazards would be possible within any more cellular storms, but a linear mode is expected to dominant, with some potential for the development of an organized MCS. Damaging gusts will be the primary risk across this region. ...Upper OH Valley into the northern Mid-Atlantic... Afternoon/early evening thunderstorms are possible from the Upper OH Valley into the Northeast as the modest, convectively augmented shortwave trough interacts with the warm and moist airmass over the region. Shear will likely be modest, mitigating the potential for organized storms. However, moderate buoyancy and steep low-level lapse rates will support to the potential for strong downbursts with the more robust storms. ...Central High Plains into the Central Plains... Some of the guidance, particularly the CAMs, has trended towards more storm development across the central High Plains during the late afternoon/early evening. The modest shortwave trough progressing through the northern periphery of the upper ridge mentioned in the synopsis appears to be the impetus for these storms, providing the large-scale ascent needed for initiation. High cloud bases and steep low-level lapse rates will support strong outflow, with some cold-pool amalgamation and the development of an organized MCS possible. Uncertainty regarding storm coverage and location of greatest severe potential precludes higher probabilities with this outlook. ...South-Central/Southeast AZ... Modest easterly mid-level flow is expected across the region, which will be located on the western periphery of the upper ridge. Afternoon thunderstorm development is anticipated over the high terrain, with storms then moving westward off into lower elevations. A few strong gusts are possible as these storms move into the well-mixed airmass over the lower elevations. ..Mosier.. 07/14/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST INTO PORTIONS OF THE MID MISSISSIPPI VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Strong to severe thunderstorms are possible from the Upper Midwest into the Mid Mississippi Valley and Upper Great Lakes region on Monday. Isolated severe thunderstorms are also possible across the central Plains as well as south-central/southeast Arizona. ...Synopsis... Upper ridging is forecast to persist across the southern CONUS on Monday, while upper troughing extends across central Canada. A belt of enhanced, broadly cyclonic upper flow will exist between these two areas, extending across much of the northern CONUS. Several shortwave troughs are expected to progress through this corridor, with the most prominent wave extending from southern Manitoba southward across the Dakotas early Monday. This shortwave is forecast to progress eastward/east-southeastward across the Upper Midwest, Upper Great Lakes, and southern/eastern Ontario. Another shortwave trough, likely augmented by Sunday night's thunderstorms over the Mid MS Valley, is expected to extend from Lower MI into the Middle OH Valley early Monday night. This shortwave is then expected to continue eastward through the Upper OH Valley and Northeast/northern Mid-Atlantic during the day. Lastly, there is some chance another shortwave trough progresses through the northern periphery of the Southwest upper ridging, emerging into the central Plains and continuing eastward in the Mid MS Valley. Guidance varies on the amplitude and speed of this shortwave, which limits forecast confidence on its potential evolution and impacts. The surface pattern will be convoluted by several areas of antecedent convection, particularly from the Upper Midwest into the Mid MS and OH Valleys where storm outflow appears most likely. General expectation is for warm front to extend eastward from a surface low near the SD/NE/IA border intersection along the MN/IA border vicinity into southern WI. This front will likely extend eastward across the northern portions of the OH Valley, but with a more stationary character. A cold front attendant to the Manitoba/Dakotas shortwave is expected push southward across the Dakotas and into NE and southeastward across the Upper Midwest. By 00Z this front will likely extend from a low over northwest Ontario southwestward to another low over north-central KS. ...Upper MS Valley into the Middle OH Valley and Lower MI... Thunderstorms will likely be ongoing ahead of the cold front across the Upper MS Valley early Monday morning. These early storms are expected to be elevated, but should trend towards becoming more surface based as they progress southeastward and the airmass destabilizes. The strength of the buoyancy within the downstream airmass will depend on the evolution of Sunday night's storms, with at least some potential for some cooler and drier conditions. However, consensus among the guidance is for low 70s dewpoints and strong buoyancy during the afternoon. These thermodynamic conditions, coupled with moderate vertical shear, would support strong to severe thunderstorms. All severe hazards would be possible within any more cellular storms, but a linear mode is expected to dominant, with some potential for the development of an organized MCS. Damaging gusts will be the primary risk across this region. ...Upper OH Valley into the northern Mid-Atlantic... Afternoon/early evening thunderstorms are possible from the Upper OH Valley into the Northeast as the modest, convectively augmented shortwave trough interacts with the warm and moist airmass over the region. Shear will likely be modest, mitigating the potential for organized storms. However, moderate buoyancy and steep low-level lapse rates will support to the potential for strong downbursts with the more robust storms. ...Central High Plains into the Central Plains... Some of the guidance, particularly the CAMs, has trended towards more storm development across the central High Plains during the late afternoon/early evening. The modest shortwave trough progressing through the northern periphery of the upper ridge mentioned in the synopsis appears to be the impetus for these storms, providing the large-scale ascent needed for initiation. High cloud bases and steep low-level lapse rates will support strong outflow, with some cold-pool amalgamation and the development of an organized MCS possible. Uncertainty regarding storm coverage and location of greatest severe potential precludes higher probabilities with this outlook. ...South-Central/Southeast AZ... Modest easterly mid-level flow is expected across the region, which will be located on the western periphery of the upper ridge. Afternoon thunderstorm development is anticipated over the high terrain, with storms then moving westward off into lower elevations. A few strong gusts are possible as these storms move into the well-mixed airmass over the lower elevations. ..Mosier.. 07/14/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST INTO PORTIONS OF THE MID MISSISSIPPI VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Strong to severe thunderstorms are possible from the Upper Midwest into the Mid Mississippi Valley and Upper Great Lakes region on Monday. Isolated severe thunderstorms are also possible across the central Plains as well as south-central/southeast Arizona. ...Synopsis... Upper ridging is forecast to persist across the southern CONUS on Monday, while upper troughing extends across central Canada. A belt of enhanced, broadly cyclonic upper flow will exist between these two areas, extending across much of the northern CONUS. Several shortwave troughs are expected to progress through this corridor, with the most prominent wave extending from southern Manitoba southward across the Dakotas early Monday. This shortwave is forecast to progress eastward/east-southeastward across the Upper Midwest, Upper Great Lakes, and southern/eastern Ontario. Another shortwave trough, likely augmented by Sunday night's thunderstorms over the Mid MS Valley, is expected to extend from Lower MI into the Middle OH Valley early Monday night. This shortwave is then expected to continue eastward through the Upper OH Valley and Northeast/northern Mid-Atlantic during the day. Lastly, there is some chance another shortwave trough progresses through the northern periphery of the Southwest upper ridging, emerging into the central Plains and continuing eastward in the Mid MS Valley. Guidance varies on the amplitude and speed of this shortwave, which limits forecast confidence on its potential evolution and impacts. The surface pattern will be convoluted by several areas of antecedent convection, particularly from the Upper Midwest into the Mid MS and OH Valleys where storm outflow appears most likely. General expectation is for warm front to extend eastward from a surface low near the SD/NE/IA border intersection along the MN/IA border vicinity into southern WI. This front will likely extend eastward across the northern portions of the OH Valley, but with a more stationary character. A cold front attendant to the Manitoba/Dakotas shortwave is expected push southward across the Dakotas and into NE and southeastward across the Upper Midwest. By 00Z this front will likely extend from a low over northwest Ontario southwestward to another low over north-central KS. ...Upper MS Valley into the Middle OH Valley and Lower MI... Thunderstorms will likely be ongoing ahead of the cold front across the Upper MS Valley early Monday morning. These early storms are expected to be elevated, but should trend towards becoming more surface based as they progress southeastward and the airmass destabilizes. The strength of the buoyancy within the downstream airmass will depend on the evolution of Sunday night's storms, with at least some potential for some cooler and drier conditions. However, consensus among the guidance is for low 70s dewpoints and strong buoyancy during the afternoon. These thermodynamic conditions, coupled with moderate vertical shear, would support strong to severe thunderstorms. All severe hazards would be possible within any more cellular storms, but a linear mode is expected to dominant, with some potential for the development of an organized MCS. Damaging gusts will be the primary risk across this region. ...Upper OH Valley into the northern Mid-Atlantic... Afternoon/early evening thunderstorms are possible from the Upper OH Valley into the Northeast as the modest, convectively augmented shortwave trough interacts with the warm and moist airmass over the region. Shear will likely be modest, mitigating the potential for organized storms. However, moderate buoyancy and steep low-level lapse rates will support to the potential for strong downbursts with the more robust storms. ...Central High Plains into the Central Plains... Some of the guidance, particularly the CAMs, has trended towards more storm development across the central High Plains during the late afternoon/early evening. The modest shortwave trough progressing through the northern periphery of the upper ridge mentioned in the synopsis appears to be the impetus for these storms, providing the large-scale ascent needed for initiation. High cloud bases and steep low-level lapse rates will support strong outflow, with some cold-pool amalgamation and the development of an organized MCS possible. Uncertainty regarding storm coverage and location of greatest severe potential precludes higher probabilities with this outlook. ...South-Central/Southeast AZ... Modest easterly mid-level flow is expected across the region, which will be located on the western periphery of the upper ridge. Afternoon thunderstorm development is anticipated over the high terrain, with storms then moving westward off into lower elevations. A few strong gusts are possible as these storms move into the well-mixed airmass over the lower elevations. ..Mosier.. 07/14/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST INTO PORTIONS OF THE MID MISSISSIPPI VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Strong to severe thunderstorms are possible from the Upper Midwest into the Mid Mississippi Valley and Upper Great Lakes region on Monday. Isolated severe thunderstorms are also possible across the central Plains as well as south-central/southeast Arizona. ...Synopsis... Upper ridging is forecast to persist across the southern CONUS on Monday, while upper troughing extends across central Canada. A belt of enhanced, broadly cyclonic upper flow will exist between these two areas, extending across much of the northern CONUS. Several shortwave troughs are expected to progress through this corridor, with the most prominent wave extending from southern Manitoba southward across the Dakotas early Monday. This shortwave is forecast to progress eastward/east-southeastward across the Upper Midwest, Upper Great Lakes, and southern/eastern Ontario. Another shortwave trough, likely augmented by Sunday night's thunderstorms over the Mid MS Valley, is expected to extend from Lower MI into the Middle OH Valley early Monday night. This shortwave is then expected to continue eastward through the Upper OH Valley and Northeast/northern Mid-Atlantic during the day. Lastly, there is some chance another shortwave trough progresses through the northern periphery of the Southwest upper ridging, emerging into the central Plains and continuing eastward in the Mid MS Valley. Guidance varies on the amplitude and speed of this shortwave, which limits forecast confidence on its potential evolution and impacts. The surface pattern will be convoluted by several areas of antecedent convection, particularly from the Upper Midwest into the Mid MS and OH Valleys where storm outflow appears most likely. General expectation is for warm front to extend eastward from a surface low near the SD/NE/IA border intersection along the MN/IA border vicinity into southern WI. This front will likely extend eastward across the northern portions of the OH Valley, but with a more stationary character. A cold front attendant to the Manitoba/Dakotas shortwave is expected push southward across the Dakotas and into NE and southeastward across the Upper Midwest. By 00Z this front will likely extend from a low over northwest Ontario southwestward to another low over north-central KS. ...Upper MS Valley into the Middle OH Valley and Lower MI... Thunderstorms will likely be ongoing ahead of the cold front across the Upper MS Valley early Monday morning. These early storms are expected to be elevated, but should trend towards becoming more surface based as they progress southeastward and the airmass destabilizes. The strength of the buoyancy within the downstream airmass will depend on the evolution of Sunday night's storms, with at least some potential for some cooler and drier conditions. However, consensus among the guidance is for low 70s dewpoints and strong buoyancy during the afternoon. These thermodynamic conditions, coupled with moderate vertical shear, would support strong to severe thunderstorms. All severe hazards would be possible within any more cellular storms, but a linear mode is expected to dominant, with some potential for the development of an organized MCS. Damaging gusts will be the primary risk across this region. ...Upper OH Valley into the northern Mid-Atlantic... Afternoon/early evening thunderstorms are possible from the Upper OH Valley into the Northeast as the modest, convectively augmented shortwave trough interacts with the warm and moist airmass over the region. Shear will likely be modest, mitigating the potential for organized storms. However, moderate buoyancy and steep low-level lapse rates will support to the potential for strong downbursts with the more robust storms. ...Central High Plains into the Central Plains... Some of the guidance, particularly the CAMs, has trended towards more storm development across the central High Plains during the late afternoon/early evening. The modest shortwave trough progressing through the northern periphery of the upper ridge mentioned in the synopsis appears to be the impetus for these storms, providing the large-scale ascent needed for initiation. High cloud bases and steep low-level lapse rates will support strong outflow, with some cold-pool amalgamation and the development of an organized MCS possible. Uncertainty regarding storm coverage and location of greatest severe potential precludes higher probabilities with this outlook. ...South-Central/Southeast AZ... Modest easterly mid-level flow is expected across the region, which will be located on the western periphery of the upper ridge. Afternoon thunderstorm development is anticipated over the high terrain, with storms then moving westward off into lower elevations. A few strong gusts are possible as these storms move into the well-mixed airmass over the lower elevations. ..Mosier.. 07/14/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST INTO PORTIONS OF THE MID MISSISSIPPI VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Strong to severe thunderstorms are possible from the Upper Midwest into the Mid Mississippi Valley and Upper Great Lakes region on Monday. Isolated severe thunderstorms are also possible across the central Plains as well as south-central/southeast Arizona. ...Synopsis... Upper ridging is forecast to persist across the southern CONUS on Monday, while upper troughing extends across central Canada. A belt of enhanced, broadly cyclonic upper flow will exist between these two areas, extending across much of the northern CONUS. Several shortwave troughs are expected to progress through this corridor, with the most prominent wave extending from southern Manitoba southward across the Dakotas early Monday. This shortwave is forecast to progress eastward/east-southeastward across the Upper Midwest, Upper Great Lakes, and southern/eastern Ontario. Another shortwave trough, likely augmented by Sunday night's thunderstorms over the Mid MS Valley, is expected to extend from Lower MI into the Middle OH Valley early Monday night. This shortwave is then expected to continue eastward through the Upper OH Valley and Northeast/northern Mid-Atlantic during the day. Lastly, there is some chance another shortwave trough progresses through the northern periphery of the Southwest upper ridging, emerging into the central Plains and continuing eastward in the Mid MS Valley. Guidance varies on the amplitude and speed of this shortwave, which limits forecast confidence on its potential evolution and impacts. The surface pattern will be convoluted by several areas of antecedent convection, particularly from the Upper Midwest into the Mid MS and OH Valleys where storm outflow appears most likely. General expectation is for warm front to extend eastward from a surface low near the SD/NE/IA border intersection along the MN/IA border vicinity into southern WI. This front will likely extend eastward across the northern portions of the OH Valley, but with a more stationary character. A cold front attendant to the Manitoba/Dakotas shortwave is expected push southward across the Dakotas and into NE and southeastward across the Upper Midwest. By 00Z this front will likely extend from a low over northwest Ontario southwestward to another low over north-central KS. ...Upper MS Valley into the Middle OH Valley and Lower MI... Thunderstorms will likely be ongoing ahead of the cold front across the Upper MS Valley early Monday morning. These early storms are expected to be elevated, but should trend towards becoming more surface based as they progress southeastward and the airmass destabilizes. The strength of the buoyancy within the downstream airmass will depend on the evolution of Sunday night's storms, with at least some potential for some cooler and drier conditions. However, consensus among the guidance is for low 70s dewpoints and strong buoyancy during the afternoon. These thermodynamic conditions, coupled with moderate vertical shear, would support strong to severe thunderstorms. All severe hazards would be possible within any more cellular storms, but a linear mode is expected to dominant, with some potential for the development of an organized MCS. Damaging gusts will be the primary risk across this region. ...Upper OH Valley into the northern Mid-Atlantic... Afternoon/early evening thunderstorms are possible from the Upper OH Valley into the Northeast as the modest, convectively augmented shortwave trough interacts with the warm and moist airmass over the region. Shear will likely be modest, mitigating the potential for organized storms. However, moderate buoyancy and steep low-level lapse rates will support to the potential for strong downbursts with the more robust storms. ...Central High Plains into the Central Plains... Some of the guidance, particularly the CAMs, has trended towards more storm development across the central High Plains during the late afternoon/early evening. The modest shortwave trough progressing through the northern periphery of the upper ridge mentioned in the synopsis appears to be the impetus for these storms, providing the large-scale ascent needed for initiation. High cloud bases and steep low-level lapse rates will support strong outflow, with some cold-pool amalgamation and the development of an organized MCS possible. Uncertainty regarding storm coverage and location of greatest severe potential precludes higher probabilities with this outlook. ...South-Central/Southeast AZ... Modest easterly mid-level flow is expected across the region, which will be located on the western periphery of the upper ridge. Afternoon thunderstorm development is anticipated over the high terrain, with storms then moving westward off into lower elevations. A few strong gusts are possible as these storms move into the well-mixed airmass over the lower elevations. ..Mosier.. 07/14/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST INTO PORTIONS OF THE MID MISSISSIPPI VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Strong to severe thunderstorms are possible from the Upper Midwest into the Mid Mississippi Valley and Upper Great Lakes region on Monday. Isolated severe thunderstorms are also possible across the central Plains as well as south-central/southeast Arizona. ...Synopsis... Upper ridging is forecast to persist across the southern CONUS on Monday, while upper troughing extends across central Canada. A belt of enhanced, broadly cyclonic upper flow will exist between these two areas, extending across much of the northern CONUS. Several shortwave troughs are expected to progress through this corridor, with the most prominent wave extending from southern Manitoba southward across the Dakotas early Monday. This shortwave is forecast to progress eastward/east-southeastward across the Upper Midwest, Upper Great Lakes, and southern/eastern Ontario. Another shortwave trough, likely augmented by Sunday night's thunderstorms over the Mid MS Valley, is expected to extend from Lower MI into the Middle OH Valley early Monday night. This shortwave is then expected to continue eastward through the Upper OH Valley and Northeast/northern Mid-Atlantic during the day. Lastly, there is some chance another shortwave trough progresses through the northern periphery of the Southwest upper ridging, emerging into the central Plains and continuing eastward in the Mid MS Valley. Guidance varies on the amplitude and speed of this shortwave, which limits forecast confidence on its potential evolution and impacts. The surface pattern will be convoluted by several areas of antecedent convection, particularly from the Upper Midwest into the Mid MS and OH Valleys where storm outflow appears most likely. General expectation is for warm front to extend eastward from a surface low near the SD/NE/IA border intersection along the MN/IA border vicinity into southern WI. This front will likely extend eastward across the northern portions of the OH Valley, but with a more stationary character. A cold front attendant to the Manitoba/Dakotas shortwave is expected push southward across the Dakotas and into NE and southeastward across the Upper Midwest. By 00Z this front will likely extend from a low over northwest Ontario southwestward to another low over north-central KS. ...Upper MS Valley into the Middle OH Valley and Lower MI... Thunderstorms will likely be ongoing ahead of the cold front across the Upper MS Valley early Monday morning. These early storms are expected to be elevated, but should trend towards becoming more surface based as they progress southeastward and the airmass destabilizes. The strength of the buoyancy within the downstream airmass will depend on the evolution of Sunday night's storms, with at least some potential for some cooler and drier conditions. However, consensus among the guidance is for low 70s dewpoints and strong buoyancy during the afternoon. These thermodynamic conditions, coupled with moderate vertical shear, would support strong to severe thunderstorms. All severe hazards would be possible within any more cellular storms, but a linear mode is expected to dominant, with some potential for the development of an organized MCS. Damaging gusts will be the primary risk across this region. ...Upper OH Valley into the northern Mid-Atlantic... Afternoon/early evening thunderstorms are possible from the Upper OH Valley into the Northeast as the modest, convectively augmented shortwave trough interacts with the warm and moist airmass over the region. Shear will likely be modest, mitigating the potential for organized storms. However, moderate buoyancy and steep low-level lapse rates will support to the potential for strong downbursts with the more robust storms. ...Central High Plains into the Central Plains... Some of the guidance, particularly the CAMs, has trended towards more storm development across the central High Plains during the late afternoon/early evening. The modest shortwave trough progressing through the northern periphery of the upper ridge mentioned in the synopsis appears to be the impetus for these storms, providing the large-scale ascent needed for initiation. High cloud bases and steep low-level lapse rates will support strong outflow, with some cold-pool amalgamation and the development of an organized MCS possible. Uncertainty regarding storm coverage and location of greatest severe potential precludes higher probabilities with this outlook. ...South-Central/Southeast AZ... Modest easterly mid-level flow is expected across the region, which will be located on the western periphery of the upper ridge. Afternoon thunderstorm development is anticipated over the high terrain, with storms then moving westward off into lower elevations. A few strong gusts are possible as these storms move into the well-mixed airmass over the lower elevations. ..Mosier.. 07/14/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST INTO PORTIONS OF THE MID MISSISSIPPI VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Strong to severe thunderstorms are possible from the Upper Midwest into the Mid Mississippi Valley and Upper Great Lakes region on Monday. Isolated severe thunderstorms are also possible across the central Plains as well as south-central/southeast Arizona. ...Synopsis... Upper ridging is forecast to persist across the southern CONUS on Monday, while upper troughing extends across central Canada. A belt of enhanced, broadly cyclonic upper flow will exist between these two areas, extending across much of the northern CONUS. Several shortwave troughs are expected to progress through this corridor, with the most prominent wave extending from southern Manitoba southward across the Dakotas early Monday. This shortwave is forecast to progress eastward/east-southeastward across the Upper Midwest, Upper Great Lakes, and southern/eastern Ontario. Another shortwave trough, likely augmented by Sunday night's thunderstorms over the Mid MS Valley, is expected to extend from Lower MI into the Middle OH Valley early Monday night. This shortwave is then expected to continue eastward through the Upper OH Valley and Northeast/northern Mid-Atlantic during the day. Lastly, there is some chance another shortwave trough progresses through the northern periphery of the Southwest upper ridging, emerging into the central Plains and continuing eastward in the Mid MS Valley. Guidance varies on the amplitude and speed of this shortwave, which limits forecast confidence on its potential evolution and impacts. The surface pattern will be convoluted by several areas of antecedent convection, particularly from the Upper Midwest into the Mid MS and OH Valleys where storm outflow appears most likely. General expectation is for warm front to extend eastward from a surface low near the SD/NE/IA border intersection along the MN/IA border vicinity into southern WI. This front will likely extend eastward across the northern portions of the OH Valley, but with a more stationary character. A cold front attendant to the Manitoba/Dakotas shortwave is expected push southward across the Dakotas and into NE and southeastward across the Upper Midwest. By 00Z this front will likely extend from a low over northwest Ontario southwestward to another low over north-central KS. ...Upper MS Valley into the Middle OH Valley and Lower MI... Thunderstorms will likely be ongoing ahead of the cold front across the Upper MS Valley early Monday morning. These early storms are expected to be elevated, but should trend towards becoming more surface based as they progress southeastward and the airmass destabilizes. The strength of the buoyancy within the downstream airmass will depend on the evolution of Sunday night's storms, with at least some potential for some cooler and drier conditions. However, consensus among the guidance is for low 70s dewpoints and strong buoyancy during the afternoon. These thermodynamic conditions, coupled with moderate vertical shear, would support strong to severe thunderstorms. All severe hazards would be possible within any more cellular storms, but a linear mode is expected to dominant, with some potential for the development of an organized MCS. Damaging gusts will be the primary risk across this region. ...Upper OH Valley into the northern Mid-Atlantic... Afternoon/early evening thunderstorms are possible from the Upper OH Valley into the Northeast as the modest, convectively augmented shortwave trough interacts with the warm and moist airmass over the region. Shear will likely be modest, mitigating the potential for organized storms. However, moderate buoyancy and steep low-level lapse rates will support to the potential for strong downbursts with the more robust storms. ...Central High Plains into the Central Plains... Some of the guidance, particularly the CAMs, has trended towards more storm development across the central High Plains during the late afternoon/early evening. The modest shortwave trough progressing through the northern periphery of the upper ridge mentioned in the synopsis appears to be the impetus for these storms, providing the large-scale ascent needed for initiation. High cloud bases and steep low-level lapse rates will support strong outflow, with some cold-pool amalgamation and the development of an organized MCS possible. Uncertainty regarding storm coverage and location of greatest severe potential precludes higher probabilities with this outlook. ...South-Central/Southeast AZ... Modest easterly mid-level flow is expected across the region, which will be located on the western periphery of the upper ridge. Afternoon thunderstorm development is anticipated over the high terrain, with storms then moving westward off into lower elevations. A few strong gusts are possible as these storms move into the well-mixed airmass over the lower elevations. ..Mosier.. 07/14/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST INTO PORTIONS OF THE MID MISSISSIPPI VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Strong to severe thunderstorms are possible from the Upper Midwest into the Mid Mississippi Valley and Upper Great Lakes region on Monday. Isolated severe thunderstorms are also possible across the central Plains as well as south-central/southeast Arizona. ...Synopsis... Upper ridging is forecast to persist across the southern CONUS on Monday, while upper troughing extends across central Canada. A belt of enhanced, broadly cyclonic upper flow will exist between these two areas, extending across much of the northern CONUS. Several shortwave troughs are expected to progress through this corridor, with the most prominent wave extending from southern Manitoba southward across the Dakotas early Monday. This shortwave is forecast to progress eastward/east-southeastward across the Upper Midwest, Upper Great Lakes, and southern/eastern Ontario. Another shortwave trough, likely augmented by Sunday night's thunderstorms over the Mid MS Valley, is expected to extend from Lower MI into the Middle OH Valley early Monday night. This shortwave is then expected to continue eastward through the Upper OH Valley and Northeast/northern Mid-Atlantic during the day. Lastly, there is some chance another shortwave trough progresses through the northern periphery of the Southwest upper ridging, emerging into the central Plains and continuing eastward in the Mid MS Valley. Guidance varies on the amplitude and speed of this shortwave, which limits forecast confidence on its potential evolution and impacts. The surface pattern will be convoluted by several areas of antecedent convection, particularly from the Upper Midwest into the Mid MS and OH Valleys where storm outflow appears most likely. General expectation is for warm front to extend eastward from a surface low near the SD/NE/IA border intersection along the MN/IA border vicinity into southern WI. This front will likely extend eastward across the northern portions of the OH Valley, but with a more stationary character. A cold front attendant to the Manitoba/Dakotas shortwave is expected push southward across the Dakotas and into NE and southeastward across the Upper Midwest. By 00Z this front will likely extend from a low over northwest Ontario southwestward to another low over north-central KS. ...Upper MS Valley into the Middle OH Valley and Lower MI... Thunderstorms will likely be ongoing ahead of the cold front across the Upper MS Valley early Monday morning. These early storms are expected to be elevated, but should trend towards becoming more surface based as they progress southeastward and the airmass destabilizes. The strength of the buoyancy within the downstream airmass will depend on the evolution of Sunday night's storms, with at least some potential for some cooler and drier conditions. However, consensus among the guidance is for low 70s dewpoints and strong buoyancy during the afternoon. These thermodynamic conditions, coupled with moderate vertical shear, would support strong to severe thunderstorms. All severe hazards would be possible within any more cellular storms, but a linear mode is expected to dominant, with some potential for the development of an organized MCS. Damaging gusts will be the primary risk across this region. ...Upper OH Valley into the northern Mid-Atlantic... Afternoon/early evening thunderstorms are possible from the Upper OH Valley into the Northeast as the modest, convectively augmented shortwave trough interacts with the warm and moist airmass over the region. Shear will likely be modest, mitigating the potential for organized storms. However, moderate buoyancy and steep low-level lapse rates will support to the potential for strong downbursts with the more robust storms. ...Central High Plains into the Central Plains... Some of the guidance, particularly the CAMs, has trended towards more storm development across the central High Plains during the late afternoon/early evening. The modest shortwave trough progressing through the northern periphery of the upper ridge mentioned in the synopsis appears to be the impetus for these storms, providing the large-scale ascent needed for initiation. High cloud bases and steep low-level lapse rates will support strong outflow, with some cold-pool amalgamation and the development of an organized MCS possible. Uncertainty regarding storm coverage and location of greatest severe potential precludes higher probabilities with this outlook. ...South-Central/Southeast AZ... Modest easterly mid-level flow is expected across the region, which will be located on the western periphery of the upper ridge. Afternoon thunderstorm development is anticipated over the high terrain, with storms then moving westward off into lower elevations. A few strong gusts are possible as these storms move into the well-mixed airmass over the lower elevations. ..Mosier.. 07/14/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST INTO PORTIONS OF THE MID MISSISSIPPI VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Strong to severe thunderstorms are possible from the Upper Midwest into the Mid Mississippi Valley and Upper Great Lakes region on Monday. Isolated severe thunderstorms are also possible across the central Plains as well as south-central/southeast Arizona. ...Synopsis... Upper ridging is forecast to persist across the southern CONUS on Monday, while upper troughing extends across central Canada. A belt of enhanced, broadly cyclonic upper flow will exist between these two areas, extending across much of the northern CONUS. Several shortwave troughs are expected to progress through this corridor, with the most prominent wave extending from southern Manitoba southward across the Dakotas early Monday. This shortwave is forecast to progress eastward/east-southeastward across the Upper Midwest, Upper Great Lakes, and southern/eastern Ontario. Another shortwave trough, likely augmented by Sunday night's thunderstorms over the Mid MS Valley, is expected to extend from Lower MI into the Middle OH Valley early Monday night. This shortwave is then expected to continue eastward through the Upper OH Valley and Northeast/northern Mid-Atlantic during the day. Lastly, there is some chance another shortwave trough progresses through the northern periphery of the Southwest upper ridging, emerging into the central Plains and continuing eastward in the Mid MS Valley. Guidance varies on the amplitude and speed of this shortwave, which limits forecast confidence on its potential evolution and impacts. The surface pattern will be convoluted by several areas of antecedent convection, particularly from the Upper Midwest into the Mid MS and OH Valleys where storm outflow appears most likely. General expectation is for warm front to extend eastward from a surface low near the SD/NE/IA border intersection along the MN/IA border vicinity into southern WI. This front will likely extend eastward across the northern portions of the OH Valley, but with a more stationary character. A cold front attendant to the Manitoba/Dakotas shortwave is expected push southward across the Dakotas and into NE and southeastward across the Upper Midwest. By 00Z this front will likely extend from a low over northwest Ontario southwestward to another low over north-central KS. ...Upper MS Valley into the Middle OH Valley and Lower MI... Thunderstorms will likely be ongoing ahead of the cold front across the Upper MS Valley early Monday morning. These early storms are expected to be elevated, but should trend towards becoming more surface based as they progress southeastward and the airmass destabilizes. The strength of the buoyancy within the downstream airmass will depend on the evolution of Sunday night's storms, with at least some potential for some cooler and drier conditions. However, consensus among the guidance is for low 70s dewpoints and strong buoyancy during the afternoon. These thermodynamic conditions, coupled with moderate vertical shear, would support strong to severe thunderstorms. All severe hazards would be possible within any more cellular storms, but a linear mode is expected to dominant, with some potential for the development of an organized MCS. Damaging gusts will be the primary risk across this region. ...Upper OH Valley into the northern Mid-Atlantic... Afternoon/early evening thunderstorms are possible from the Upper OH Valley into the Northeast as the modest, convectively augmented shortwave trough interacts with the warm and moist airmass over the region. Shear will likely be modest, mitigating the potential for organized storms. However, moderate buoyancy and steep low-level lapse rates will support to the potential for strong downbursts with the more robust storms. ...Central High Plains into the Central Plains... Some of the guidance, particularly the CAMs, has trended towards more storm development across the central High Plains during the late afternoon/early evening. The modest shortwave trough progressing through the northern periphery of the upper ridge mentioned in the synopsis appears to be the impetus for these storms, providing the large-scale ascent needed for initiation. High cloud bases and steep low-level lapse rates will support strong outflow, with some cold-pool amalgamation and the development of an organized MCS possible. Uncertainty regarding storm coverage and location of greatest severe potential precludes higher probabilities with this outlook. ...South-Central/Southeast AZ... Modest easterly mid-level flow is expected across the region, which will be located on the western periphery of the upper ridge. Afternoon thunderstorm development is anticipated over the high terrain, with storms then moving westward off into lower elevations. A few strong gusts are possible as these storms move into the well-mixed airmass over the lower elevations. ..Mosier.. 07/14/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST INTO PORTIONS OF THE MID MISSISSIPPI VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Strong to severe thunderstorms are possible from the Upper Midwest into the Mid Mississippi Valley and Upper Great Lakes region on Monday. Isolated severe thunderstorms are also possible across the central Plains as well as south-central/southeast Arizona. ...Synopsis... Upper ridging is forecast to persist across the southern CONUS on Monday, while upper troughing extends across central Canada. A belt of enhanced, broadly cyclonic upper flow will exist between these two areas, extending across much of the northern CONUS. Several shortwave troughs are expected to progress through this corridor, with the most prominent wave extending from southern Manitoba southward across the Dakotas early Monday. This shortwave is forecast to progress eastward/east-southeastward across the Upper Midwest, Upper Great Lakes, and southern/eastern Ontario. Another shortwave trough, likely augmented by Sunday night's thunderstorms over the Mid MS Valley, is expected to extend from Lower MI into the Middle OH Valley early Monday night. This shortwave is then expected to continue eastward through the Upper OH Valley and Northeast/northern Mid-Atlantic during the day. Lastly, there is some chance another shortwave trough progresses through the northern periphery of the Southwest upper ridging, emerging into the central Plains and continuing eastward in the Mid MS Valley. Guidance varies on the amplitude and speed of this shortwave, which limits forecast confidence on its potential evolution and impacts. The surface pattern will be convoluted by several areas of antecedent convection, particularly from the Upper Midwest into the Mid MS and OH Valleys where storm outflow appears most likely. General expectation is for warm front to extend eastward from a surface low near the SD/NE/IA border intersection along the MN/IA border vicinity into southern WI. This front will likely extend eastward across the northern portions of the OH Valley, but with a more stationary character. A cold front attendant to the Manitoba/Dakotas shortwave is expected push southward across the Dakotas and into NE and southeastward across the Upper Midwest. By 00Z this front will likely extend from a low over northwest Ontario southwestward to another low over north-central KS. ...Upper MS Valley into the Middle OH Valley and Lower MI... Thunderstorms will likely be ongoing ahead of the cold front across the Upper MS Valley early Monday morning. These early storms are expected to be elevated, but should trend towards becoming more surface based as they progress southeastward and the airmass destabilizes. The strength of the buoyancy within the downstream airmass will depend on the evolution of Sunday night's storms, with at least some potential for some cooler and drier conditions. However, consensus among the guidance is for low 70s dewpoints and strong buoyancy during the afternoon. These thermodynamic conditions, coupled with moderate vertical shear, would support strong to severe thunderstorms. All severe hazards would be possible within any more cellular storms, but a linear mode is expected to dominant, with some potential for the development of an organized MCS. Damaging gusts will be the primary risk across this region. ...Upper OH Valley into the northern Mid-Atlantic... Afternoon/early evening thunderstorms are possible from the Upper OH Valley into the Northeast as the modest, convectively augmented shortwave trough interacts with the warm and moist airmass over the region. Shear will likely be modest, mitigating the potential for organized storms. However, moderate buoyancy and steep low-level lapse rates will support to the potential for strong downbursts with the more robust storms. ...Central High Plains into the Central Plains... Some of the guidance, particularly the CAMs, has trended towards more storm development across the central High Plains during the late afternoon/early evening. The modest shortwave trough progressing through the northern periphery of the upper ridge mentioned in the synopsis appears to be the impetus for these storms, providing the large-scale ascent needed for initiation. High cloud bases and steep low-level lapse rates will support strong outflow, with some cold-pool amalgamation and the development of an organized MCS possible. Uncertainty regarding storm coverage and location of greatest severe potential precludes higher probabilities with this outlook. ...South-Central/Southeast AZ... Modest easterly mid-level flow is expected across the region, which will be located on the western periphery of the upper ridge. Afternoon thunderstorm development is anticipated over the high terrain, with storms then moving westward off into lower elevations. A few strong gusts are possible as these storms move into the well-mixed airmass over the lower elevations. ..Mosier.. 07/14/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST INTO PORTIONS OF THE MID MISSISSIPPI VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Strong to severe thunderstorms are possible from the Upper Midwest into the Mid Mississippi Valley and Upper Great Lakes region on Monday. Isolated severe thunderstorms are also possible across the central Plains as well as south-central/southeast Arizona. ...Synopsis... Upper ridging is forecast to persist across the southern CONUS on Monday, while upper troughing extends across central Canada. A belt of enhanced, broadly cyclonic upper flow will exist between these two areas, extending across much of the northern CONUS. Several shortwave troughs are expected to progress through this corridor, with the most prominent wave extending from southern Manitoba southward across the Dakotas early Monday. This shortwave is forecast to progress eastward/east-southeastward across the Upper Midwest, Upper Great Lakes, and southern/eastern Ontario. Another shortwave trough, likely augmented by Sunday night's thunderstorms over the Mid MS Valley, is expected to extend from Lower MI into the Middle OH Valley early Monday night. This shortwave is then expected to continue eastward through the Upper OH Valley and Northeast/northern Mid-Atlantic during the day. Lastly, there is some chance another shortwave trough progresses through the northern periphery of the Southwest upper ridging, emerging into the central Plains and continuing eastward in the Mid MS Valley. Guidance varies on the amplitude and speed of this shortwave, which limits forecast confidence on its potential evolution and impacts. The surface pattern will be convoluted by several areas of antecedent convection, particularly from the Upper Midwest into the Mid MS and OH Valleys where storm outflow appears most likely. General expectation is for warm front to extend eastward from a surface low near the SD/NE/IA border intersection along the MN/IA border vicinity into southern WI. This front will likely extend eastward across the northern portions of the OH Valley, but with a more stationary character. A cold front attendant to the Manitoba/Dakotas shortwave is expected push southward across the Dakotas and into NE and southeastward across the Upper Midwest. By 00Z this front will likely extend from a low over northwest Ontario southwestward to another low over north-central KS. ...Upper MS Valley into the Middle OH Valley and Lower MI... Thunderstorms will likely be ongoing ahead of the cold front across the Upper MS Valley early Monday morning. These early storms are expected to be elevated, but should trend towards becoming more surface based as they progress southeastward and the airmass destabilizes. The strength of the buoyancy within the downstream airmass will depend on the evolution of Sunday night's storms, with at least some potential for some cooler and drier conditions. However, consensus among the guidance is for low 70s dewpoints and strong buoyancy during the afternoon. These thermodynamic conditions, coupled with moderate vertical shear, would support strong to severe thunderstorms. All severe hazards would be possible within any more cellular storms, but a linear mode is expected to dominant, with some potential for the development of an organized MCS. Damaging gusts will be the primary risk across this region. ...Upper OH Valley into the northern Mid-Atlantic... Afternoon/early evening thunderstorms are possible from the Upper OH Valley into the Northeast as the modest, convectively augmented shortwave trough interacts with the warm and moist airmass over the region. Shear will likely be modest, mitigating the potential for organized storms. However, moderate buoyancy and steep low-level lapse rates will support to the potential for strong downbursts with the more robust storms. ...Central High Plains into the Central Plains... Some of the guidance, particularly the CAMs, has trended towards more storm development across the central High Plains during the late afternoon/early evening. The modest shortwave trough progressing through the northern periphery of the upper ridge mentioned in the synopsis appears to be the impetus for these storms, providing the large-scale ascent needed for initiation. High cloud bases and steep low-level lapse rates will support strong outflow, with some cold-pool amalgamation and the development of an organized MCS possible. Uncertainty regarding storm coverage and location of greatest severe potential precludes higher probabilities with this outlook. ...South-Central/Southeast AZ... Modest easterly mid-level flow is expected across the region, which will be located on the western periphery of the upper ridge. Afternoon thunderstorm development is anticipated over the high terrain, with storms then moving westward off into lower elevations. A few strong gusts are possible as these storms move into the well-mixed airmass over the lower elevations. ..Mosier.. 07/14/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST INTO PORTIONS OF THE MID MISSISSIPPI VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Strong to severe thunderstorms are possible from the Upper Midwest into the Mid Mississippi Valley and Upper Great Lakes region on Monday. Isolated severe thunderstorms are also possible across the central Plains as well as south-central/southeast Arizona. ...Synopsis... Upper ridging is forecast to persist across the southern CONUS on Monday, while upper troughing extends across central Canada. A belt of enhanced, broadly cyclonic upper flow will exist between these two areas, extending across much of the northern CONUS. Several shortwave troughs are expected to progress through this corridor, with the most prominent wave extending from southern Manitoba southward across the Dakotas early Monday. This shortwave is forecast to progress eastward/east-southeastward across the Upper Midwest, Upper Great Lakes, and southern/eastern Ontario. Another shortwave trough, likely augmented by Sunday night's thunderstorms over the Mid MS Valley, is expected to extend from Lower MI into the Middle OH Valley early Monday night. This shortwave is then expected to continue eastward through the Upper OH Valley and Northeast/northern Mid-Atlantic during the day. Lastly, there is some chance another shortwave trough progresses through the northern periphery of the Southwest upper ridging, emerging into the central Plains and continuing eastward in the Mid MS Valley. Guidance varies on the amplitude and speed of this shortwave, which limits forecast confidence on its potential evolution and impacts. The surface pattern will be convoluted by several areas of antecedent convection, particularly from the Upper Midwest into the Mid MS and OH Valleys where storm outflow appears most likely. General expectation is for warm front to extend eastward from a surface low near the SD/NE/IA border intersection along the MN/IA border vicinity into southern WI. This front will likely extend eastward across the northern portions of the OH Valley, but with a more stationary character. A cold front attendant to the Manitoba/Dakotas shortwave is expected push southward across the Dakotas and into NE and southeastward across the Upper Midwest. By 00Z this front will likely extend from a low over northwest Ontario southwestward to another low over north-central KS. ...Upper MS Valley into the Middle OH Valley and Lower MI... Thunderstorms will likely be ongoing ahead of the cold front across the Upper MS Valley early Monday morning. These early storms are expected to be elevated, but should trend towards becoming more surface based as they progress southeastward and the airmass destabilizes. The strength of the buoyancy within the downstream airmass will depend on the evolution of Sunday night's storms, with at least some potential for some cooler and drier conditions. However, consensus among the guidance is for low 70s dewpoints and strong buoyancy during the afternoon. These thermodynamic conditions, coupled with moderate vertical shear, would support strong to severe thunderstorms. All severe hazards would be possible within any more cellular storms, but a linear mode is expected to dominant, with some potential for the development of an organized MCS. Damaging gusts will be the primary risk across this region. ...Upper OH Valley into the northern Mid-Atlantic... Afternoon/early evening thunderstorms are possible from the Upper OH Valley into the Northeast as the modest, convectively augmented shortwave trough interacts with the warm and moist airmass over the region. Shear will likely be modest, mitigating the potential for organized storms. However, moderate buoyancy and steep low-level lapse rates will support to the potential for strong downbursts with the more robust storms. ...Central High Plains into the Central Plains... Some of the guidance, particularly the CAMs, has trended towards more storm development across the central High Plains during the late afternoon/early evening. The modest shortwave trough progressing through the northern periphery of the upper ridge mentioned in the synopsis appears to be the impetus for these storms, providing the large-scale ascent needed for initiation. High cloud bases and steep low-level lapse rates will support strong outflow, with some cold-pool amalgamation and the development of an organized MCS possible. Uncertainty regarding storm coverage and location of greatest severe potential precludes higher probabilities with this outlook. ...South-Central/Southeast AZ... Modest easterly mid-level flow is expected across the region, which will be located on the western periphery of the upper ridge. Afternoon thunderstorm development is anticipated over the high terrain, with storms then moving westward off into lower elevations. A few strong gusts are possible as these storms move into the well-mixed airmass over the lower elevations. ..Mosier.. 07/14/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0103 AM CDT Sun Jul 14 2024 Valid 151200Z - 161200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE UPPER MIDWEST INTO PORTIONS OF THE MID MISSISSIPPI VALLEY AND UPPER GREAT LAKES... ...SUMMARY... Strong to severe thunderstorms are possible from the Upper Midwest into the Mid Mississippi Valley and Upper Great Lakes region on Monday. Isolated severe thunderstorms are also possible across the central Plains as well as south-central/southeast Arizona. ...Synopsis... Upper ridging is forecast to persist across the southern CONUS on Monday, while upper troughing extends across central Canada. A belt of enhanced, broadly cyclonic upper flow will exist between these two areas, extending across much of the northern CONUS. Several shortwave troughs are expected to progress through this corridor, with the most prominent wave extending from southern Manitoba southward across the Dakotas early Monday. This shortwave is forecast to progress eastward/east-southeastward across the Upper Midwest, Upper Great Lakes, and southern/eastern Ontario. Another shortwave trough, likely augmented by Sunday night's thunderstorms over the Mid MS Valley, is expected to extend from Lower MI into the Middle OH Valley early Monday night. This shortwave is then expected to continue eastward through the Upper OH Valley and Northeast/northern Mid-Atlantic during the day. Lastly, there is some chance another shortwave trough progresses through the northern periphery of the Southwest upper ridging, emerging into the central Plains and continuing eastward in the Mid MS Valley. Guidance varies on the amplitude and speed of this shortwave, which limits forecast confidence on its potential evolution and impacts. The surface pattern will be convoluted by several areas of antecedent convection, particularly from the Upper Midwest into the Mid MS and OH Valleys where storm outflow appears most likely. General expectation is for warm front to extend eastward from a surface low near the SD/NE/IA border intersection along the MN/IA border vicinity into southern WI. This front will likely extend eastward across the northern portions of the OH Valley, but with a more stationary character. A cold front attendant to the Manitoba/Dakotas shortwave is expected push southward across the Dakotas and into NE and southeastward across the Upper Midwest. By 00Z this front will likely extend from a low over northwest Ontario southwestward to another low over north-central KS. ...Upper MS Valley into the Middle OH Valley and Lower MI... Thunderstorms will likely be ongoing ahead of the cold front across the Upper MS Valley early Monday morning. These early storms are expected to be elevated, but should trend towards becoming more surface based as they progress southeastward and the airmass destabilizes. The strength of the buoyancy within the downstream airmass will depend on the evolution of Sunday night's storms, with at least some potential for some cooler and drier conditions. However, consensus among the guidance is for low 70s dewpoints and strong buoyancy during the afternoon. These thermodynamic conditions, coupled with moderate vertical shear, would support strong to severe thunderstorms. All severe hazards would be possible within any more cellular storms, but a linear mode is expected to dominant, with some potential for the development of an organized MCS. Damaging gusts will be the primary risk across this region. ...Upper OH Valley into the northern Mid-Atlantic... Afternoon/early evening thunderstorms are possible from the Upper OH Valley into the Northeast as the modest, convectively augmented shortwave trough interacts with the warm and moist airmass over the region. Shear will likely be modest, mitigating the potential for organized storms. However, moderate buoyancy and steep low-level lapse rates will support to the potential for strong downbursts with the more robust storms. ...Central High Plains into the Central Plains... Some of the guidance, particularly the CAMs, has trended towards more storm development across the central High Plains during the late afternoon/early evening. The modest shortwave trough progressing through the northern periphery of the upper ridge mentioned in the synopsis appears to be the impetus for these storms, providing the large-scale ascent needed for initiation. High cloud bases and steep low-level lapse rates will support strong outflow, with some cold-pool amalgamation and the development of an organized MCS possible. Uncertainty regarding storm coverage and location of greatest severe potential precludes higher probabilities with this outlook. ...South-Central/Southeast AZ... Modest easterly mid-level flow is expected across the region, which will be located on the western periphery of the upper ridge. Afternoon thunderstorm development is anticipated over the high terrain, with storms then moving westward off into lower elevations. A few strong gusts are possible as these storms move into the well-mixed airmass over the lower elevations. ..Mosier.. 07/14/2024 Read more

MD 1606 CONCERNING SEVERE THUNDERSTORM WATCH 527... FOR NORTHWEST TO CENTRAL SOUTH DAKOTA
Mesoscale Discussion 1606 NWS Storm Prediction Center Norman OK 1054 PM CDT Sat Jul 13 2024 Areas affected...Northwest to central South Dakota Concerning...Severe Thunderstorm Watch 527... Valid 140354Z - 140600Z The severe weather threat for Severe Thunderstorm Watch 527 continues. SUMMARY...An intensifying MCS is expected to move into central SD in the coming hours and will pose a severe wind threat based on recent observed trends and latest forecast guidance. DISCUSSION...Upscale growth from a cluster of semi-discrete cells into an organizing MCS is well underway across far southwest ND and northwest SD. GOES IR imagery has shown a steady decrease in cloud-top temperatures over the past 30 minutes, signifying an intensification trend. Multiple severe wind reports, including an 87 mph gust in northwest SD, over the past hour or so validate this trend. The developing MCS should continue to organize and intensify as it migrates in a more buoyant air mass downstream across SD (characterized by 1500-2000 J/kg MLCAPE). While severe gusts appear possible along the length of the line, the potential for severe winds, including significant gusts (75+ mph), appears greatest ahead of a surging section of the line over Butte county, SD that is associated with the remnants of a decaying mesocyclone. Latest HRRR solutions appear to have initialized recent observed trends well and suggest the greatest severe/significant wind threat will be associated with this section of the line as it moves southeast into central SD. Downstream watch issuance will likely be needed within an hour to address this concern. ..Moore.. 07/14/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...FSD...ABR...BIS...UNR... LAT...LON 44670392 44970396 45440365 45860328 46110295 46200264 46200219 45799960 45539910 45099886 44599878 44069889 43679935 43460006 43450070 43640140 43900236 44670392 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sun Jul 14 2024 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN PLAINS INTO THE UPPER MIDWEST... ...SUMMARY... Strong to severe thunderstorms are expected from the northern Plains into the Upper Midwest. ...Northern Plains to Upper Midwest... Large-scale pattern is not expected to change appreciably during the day1 period, though some amplification is possible later in the week. Upper high is forecast to remain anchored in the Four Corners vicinity while seasonally strong mid-level flow will hold along a corridor near the US/Canadian border. Negligible height changes are expected during the first half of the period, though a few notable short waves will track east-southeast from southern AB/SK into the Great Lakes. Each short-wave trough should encourage convective development -- some of it will likely be severe. Early this morning, a weak MCS was propagating southeast across northern IL/southern Lake MI. This activity is supported by a weak disturbance and should progress into the southern Great Lakes/OH Valley later today. Diurnal heating will contribute to strong buoyancy, and robust updrafts may evolve along the leading debris field by mid day. Locally severe winds may develop if convection reintensifies. Of more concern will be convection that develops across the northern Plains later in the afternoon. A strong short-wave trough will dig southeast across southern AB by 15/00z before translating into MB/eastern Dakotas by the end of the period. It appears a weak surface low should evolve ahead of this feature over eastern MT early, then shift into central SD by peak heating. A northwest-southeast corridor of low-level warm advection will extend across the Dakotas north of a synoptic boundary that will be draped from southern MN-central SD-northeast MT. Strong boundary-layer heating will negate CINH across the High Plains such that isolated convection should develop by 22z. This activity will mature and grow upscale through the evening. Early storm mode should be supercellular, then clustering will lead to an MCS that is expected to track southeast toward the mid MO Valley. Very steep lapse rates will lead to strong buoyancy, and potentially very large hail (possibly in excess of 2 inches). Very strong winds (>70mph) may also be noted along the leading edge of the surging MCS. ..Darrow/Moore.. 07/14/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sun Jul 14 2024 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN PLAINS INTO THE UPPER MIDWEST... ...SUMMARY... Strong to severe thunderstorms are expected from the northern Plains into the Upper Midwest. ...Northern Plains to Upper Midwest... Large-scale pattern is not expected to change appreciably during the day1 period, though some amplification is possible later in the week. Upper high is forecast to remain anchored in the Four Corners vicinity while seasonally strong mid-level flow will hold along a corridor near the US/Canadian border. Negligible height changes are expected during the first half of the period, though a few notable short waves will track east-southeast from southern AB/SK into the Great Lakes. Each short-wave trough should encourage convective development -- some of it will likely be severe. Early this morning, a weak MCS was propagating southeast across northern IL/southern Lake MI. This activity is supported by a weak disturbance and should progress into the southern Great Lakes/OH Valley later today. Diurnal heating will contribute to strong buoyancy, and robust updrafts may evolve along the leading debris field by mid day. Locally severe winds may develop if convection reintensifies. Of more concern will be convection that develops across the northern Plains later in the afternoon. A strong short-wave trough will dig southeast across southern AB by 15/00z before translating into MB/eastern Dakotas by the end of the period. It appears a weak surface low should evolve ahead of this feature over eastern MT early, then shift into central SD by peak heating. A northwest-southeast corridor of low-level warm advection will extend across the Dakotas north of a synoptic boundary that will be draped from southern MN-central SD-northeast MT. Strong boundary-layer heating will negate CINH across the High Plains such that isolated convection should develop by 22z. This activity will mature and grow upscale through the evening. Early storm mode should be supercellular, then clustering will lead to an MCS that is expected to track southeast toward the mid MO Valley. Very steep lapse rates will lead to strong buoyancy, and potentially very large hail (possibly in excess of 2 inches). Very strong winds (>70mph) may also be noted along the leading edge of the surging MCS. ..Darrow/Moore.. 07/14/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1234 AM CDT Sun Jul 14 2024 Valid 141200Z - 151200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN PLAINS INTO THE UPPER MIDWEST... ...SUMMARY... Strong to severe thunderstorms are expected from the northern Plains into the Upper Midwest. ...Northern Plains to Upper Midwest... Large-scale pattern is not expected to change appreciably during the day1 period, though some amplification is possible later in the week. Upper high is forecast to remain anchored in the Four Corners vicinity while seasonally strong mid-level flow will hold along a corridor near the US/Canadian border. Negligible height changes are expected during the first half of the period, though a few notable short waves will track east-southeast from southern AB/SK into the Great Lakes. Each short-wave trough should encourage convective development -- some of it will likely be severe. Early this morning, a weak MCS was propagating southeast across northern IL/southern Lake MI. This activity is supported by a weak disturbance and should progress into the southern Great Lakes/OH Valley later today. Diurnal heating will contribute to strong buoyancy, and robust updrafts may evolve along the leading debris field by mid day. Locally severe winds may develop if convection reintensifies. Of more concern will be convection that develops across the northern Plains later in the afternoon. A strong short-wave trough will dig southeast across southern AB by 15/00z before translating into MB/eastern Dakotas by the end of the period. It appears a weak surface low should evolve ahead of this feature over eastern MT early, then shift into central SD by peak heating. A northwest-southeast corridor of low-level warm advection will extend across the Dakotas north of a synoptic boundary that will be draped from southern MN-central SD-northeast MT. Strong boundary-layer heating will negate CINH across the High Plains such that isolated convection should develop by 22z. This activity will mature and grow upscale through the evening. Early storm mode should be supercellular, then clustering will lead to an MCS that is expected to track southeast toward the mid MO Valley. Very steep lapse rates will lead to strong buoyancy, and potentially very large hail (possibly in excess of 2 inches). Very strong winds (>70mph) may also be noted along the leading edge of the surging MCS. ..Darrow/Moore.. 07/14/2024 Read more