Severe Storms

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Apr 02 2024 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE EASTERN CAROLINAS...MID-ATLANTIC AND FLORIDA PENINSULA... ...SUMMARY... Severe thunderstorms, associated with wind damage and hail, will be possible on Wednesday across parts of the eastern Carolinas and Mid-Atlantic, with a second severe threat area expected over the Florida Peninsula. ...Eastern Carolinas/Mid-Atlantic... A large upper-level low pressure system will move eastward into the southern Great Lakes on Wednesday, as a cold front advances quickly eastward through the southern and central Appalachians. Ahead of the front, a moist airmass will likely be in place across the Carolinas into southeastern Virginia, with surface dewpoints in the 60s F. As surface temperatures warm across the moist airmass, weak instability is expected to develop in most areas during the late morning and early afternoon. While some convection is expected near the front early in the period, new surface-based thunderstorms should develop along and near the moist axis around midday. These storms will likely move eastward across parts of Maryland, eastern Virginia and eastern North Carolina. Forecast soundings during the afternoon along and near the moist axis have extreme deep-layer shear, with 0-6 km shear actually reaching 90 to 100 knots by 21Z. As low-level lapse rates steepen during the day, convection should be able to mix the stronger flow down to the surface, creating a potential for wind damage. The more intense cells could also be associated with an isolated large hail threat, aided by cold temperatures aloft. ...Florida Peninsula... Mid-level flow is forecast to be west-southwesterly across the Gulf Coast states and southern Atlantic Seaboard on Wednesday. A 100 to 120 knot mid-level jet is forecast to move into the western Carolinas, as a cold front advances southward across the northern Florida Peninsula. The entrance region of the mid-level jet is forecast to move into the eastern Gulf of Mexico by Wednesday afternoon, strengthening lift and shear across the Florida Peninsula. As storms organize ahead of the front and move eastward across the central Florida Peninsula, the strong deep-layer shear may be enough to support a wind-damage threat with the more intense cells embedded in the convective line. Any severe threat should be the greatest during the mid to late afternoon, as low-level lapse rates become the steepest. A marginal hail threat is also expected. ..Broyles.. 04/02/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Apr 02 2024 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE EASTERN CAROLINAS...MID-ATLANTIC AND FLORIDA PENINSULA... ...SUMMARY... Severe thunderstorms, associated with wind damage and hail, will be possible on Wednesday across parts of the eastern Carolinas and Mid-Atlantic, with a second severe threat area expected over the Florida Peninsula. ...Eastern Carolinas/Mid-Atlantic... A large upper-level low pressure system will move eastward into the southern Great Lakes on Wednesday, as a cold front advances quickly eastward through the southern and central Appalachians. Ahead of the front, a moist airmass will likely be in place across the Carolinas into southeastern Virginia, with surface dewpoints in the 60s F. As surface temperatures warm across the moist airmass, weak instability is expected to develop in most areas during the late morning and early afternoon. While some convection is expected near the front early in the period, new surface-based thunderstorms should develop along and near the moist axis around midday. These storms will likely move eastward across parts of Maryland, eastern Virginia and eastern North Carolina. Forecast soundings during the afternoon along and near the moist axis have extreme deep-layer shear, with 0-6 km shear actually reaching 90 to 100 knots by 21Z. As low-level lapse rates steepen during the day, convection should be able to mix the stronger flow down to the surface, creating a potential for wind damage. The more intense cells could also be associated with an isolated large hail threat, aided by cold temperatures aloft. ...Florida Peninsula... Mid-level flow is forecast to be west-southwesterly across the Gulf Coast states and southern Atlantic Seaboard on Wednesday. A 100 to 120 knot mid-level jet is forecast to move into the western Carolinas, as a cold front advances southward across the northern Florida Peninsula. The entrance region of the mid-level jet is forecast to move into the eastern Gulf of Mexico by Wednesday afternoon, strengthening lift and shear across the Florida Peninsula. As storms organize ahead of the front and move eastward across the central Florida Peninsula, the strong deep-layer shear may be enough to support a wind-damage threat with the more intense cells embedded in the convective line. Any severe threat should be the greatest during the mid to late afternoon, as low-level lapse rates become the steepest. A marginal hail threat is also expected. ..Broyles.. 04/02/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Apr 02 2024 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE EASTERN CAROLINAS...MID-ATLANTIC AND FLORIDA PENINSULA... ...SUMMARY... Severe thunderstorms, associated with wind damage and hail, will be possible on Wednesday across parts of the eastern Carolinas and Mid-Atlantic, with a second severe threat area expected over the Florida Peninsula. ...Eastern Carolinas/Mid-Atlantic... A large upper-level low pressure system will move eastward into the southern Great Lakes on Wednesday, as a cold front advances quickly eastward through the southern and central Appalachians. Ahead of the front, a moist airmass will likely be in place across the Carolinas into southeastern Virginia, with surface dewpoints in the 60s F. As surface temperatures warm across the moist airmass, weak instability is expected to develop in most areas during the late morning and early afternoon. While some convection is expected near the front early in the period, new surface-based thunderstorms should develop along and near the moist axis around midday. These storms will likely move eastward across parts of Maryland, eastern Virginia and eastern North Carolina. Forecast soundings during the afternoon along and near the moist axis have extreme deep-layer shear, with 0-6 km shear actually reaching 90 to 100 knots by 21Z. As low-level lapse rates steepen during the day, convection should be able to mix the stronger flow down to the surface, creating a potential for wind damage. The more intense cells could also be associated with an isolated large hail threat, aided by cold temperatures aloft. ...Florida Peninsula... Mid-level flow is forecast to be west-southwesterly across the Gulf Coast states and southern Atlantic Seaboard on Wednesday. A 100 to 120 knot mid-level jet is forecast to move into the western Carolinas, as a cold front advances southward across the northern Florida Peninsula. The entrance region of the mid-level jet is forecast to move into the eastern Gulf of Mexico by Wednesday afternoon, strengthening lift and shear across the Florida Peninsula. As storms organize ahead of the front and move eastward across the central Florida Peninsula, the strong deep-layer shear may be enough to support a wind-damage threat with the more intense cells embedded in the convective line. Any severe threat should be the greatest during the mid to late afternoon, as low-level lapse rates become the steepest. A marginal hail threat is also expected. ..Broyles.. 04/02/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Apr 02 2024 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE EASTERN CAROLINAS...MID-ATLANTIC AND FLORIDA PENINSULA... ...SUMMARY... Severe thunderstorms, associated with wind damage and hail, will be possible on Wednesday across parts of the eastern Carolinas and Mid-Atlantic, with a second severe threat area expected over the Florida Peninsula. ...Eastern Carolinas/Mid-Atlantic... A large upper-level low pressure system will move eastward into the southern Great Lakes on Wednesday, as a cold front advances quickly eastward through the southern and central Appalachians. Ahead of the front, a moist airmass will likely be in place across the Carolinas into southeastern Virginia, with surface dewpoints in the 60s F. As surface temperatures warm across the moist airmass, weak instability is expected to develop in most areas during the late morning and early afternoon. While some convection is expected near the front early in the period, new surface-based thunderstorms should develop along and near the moist axis around midday. These storms will likely move eastward across parts of Maryland, eastern Virginia and eastern North Carolina. Forecast soundings during the afternoon along and near the moist axis have extreme deep-layer shear, with 0-6 km shear actually reaching 90 to 100 knots by 21Z. As low-level lapse rates steepen during the day, convection should be able to mix the stronger flow down to the surface, creating a potential for wind damage. The more intense cells could also be associated with an isolated large hail threat, aided by cold temperatures aloft. ...Florida Peninsula... Mid-level flow is forecast to be west-southwesterly across the Gulf Coast states and southern Atlantic Seaboard on Wednesday. A 100 to 120 knot mid-level jet is forecast to move into the western Carolinas, as a cold front advances southward across the northern Florida Peninsula. The entrance region of the mid-level jet is forecast to move into the eastern Gulf of Mexico by Wednesday afternoon, strengthening lift and shear across the Florida Peninsula. As storms organize ahead of the front and move eastward across the central Florida Peninsula, the strong deep-layer shear may be enough to support a wind-damage threat with the more intense cells embedded in the convective line. Any severe threat should be the greatest during the mid to late afternoon, as low-level lapse rates become the steepest. A marginal hail threat is also expected. ..Broyles.. 04/02/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Apr 02 2024 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE EASTERN CAROLINAS...MID-ATLANTIC AND FLORIDA PENINSULA... ...SUMMARY... Severe thunderstorms, associated with wind damage and hail, will be possible on Wednesday across parts of the eastern Carolinas and Mid-Atlantic, with a second severe threat area expected over the Florida Peninsula. ...Eastern Carolinas/Mid-Atlantic... A large upper-level low pressure system will move eastward into the southern Great Lakes on Wednesday, as a cold front advances quickly eastward through the southern and central Appalachians. Ahead of the front, a moist airmass will likely be in place across the Carolinas into southeastern Virginia, with surface dewpoints in the 60s F. As surface temperatures warm across the moist airmass, weak instability is expected to develop in most areas during the late morning and early afternoon. While some convection is expected near the front early in the period, new surface-based thunderstorms should develop along and near the moist axis around midday. These storms will likely move eastward across parts of Maryland, eastern Virginia and eastern North Carolina. Forecast soundings during the afternoon along and near the moist axis have extreme deep-layer shear, with 0-6 km shear actually reaching 90 to 100 knots by 21Z. As low-level lapse rates steepen during the day, convection should be able to mix the stronger flow down to the surface, creating a potential for wind damage. The more intense cells could also be associated with an isolated large hail threat, aided by cold temperatures aloft. ...Florida Peninsula... Mid-level flow is forecast to be west-southwesterly across the Gulf Coast states and southern Atlantic Seaboard on Wednesday. A 100 to 120 knot mid-level jet is forecast to move into the western Carolinas, as a cold front advances southward across the northern Florida Peninsula. The entrance region of the mid-level jet is forecast to move into the eastern Gulf of Mexico by Wednesday afternoon, strengthening lift and shear across the Florida Peninsula. As storms organize ahead of the front and move eastward across the central Florida Peninsula, the strong deep-layer shear may be enough to support a wind-damage threat with the more intense cells embedded in the convective line. Any severe threat should be the greatest during the mid to late afternoon, as low-level lapse rates become the steepest. A marginal hail threat is also expected. ..Broyles.. 04/02/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Apr 02 2024 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE EASTERN CAROLINAS...MID-ATLANTIC AND FLORIDA PENINSULA... ...SUMMARY... Severe thunderstorms, associated with wind damage and hail, will be possible on Wednesday across parts of the eastern Carolinas and Mid-Atlantic, with a second severe threat area expected over the Florida Peninsula. ...Eastern Carolinas/Mid-Atlantic... A large upper-level low pressure system will move eastward into the southern Great Lakes on Wednesday, as a cold front advances quickly eastward through the southern and central Appalachians. Ahead of the front, a moist airmass will likely be in place across the Carolinas into southeastern Virginia, with surface dewpoints in the 60s F. As surface temperatures warm across the moist airmass, weak instability is expected to develop in most areas during the late morning and early afternoon. While some convection is expected near the front early in the period, new surface-based thunderstorms should develop along and near the moist axis around midday. These storms will likely move eastward across parts of Maryland, eastern Virginia and eastern North Carolina. Forecast soundings during the afternoon along and near the moist axis have extreme deep-layer shear, with 0-6 km shear actually reaching 90 to 100 knots by 21Z. As low-level lapse rates steepen during the day, convection should be able to mix the stronger flow down to the surface, creating a potential for wind damage. The more intense cells could also be associated with an isolated large hail threat, aided by cold temperatures aloft. ...Florida Peninsula... Mid-level flow is forecast to be west-southwesterly across the Gulf Coast states and southern Atlantic Seaboard on Wednesday. A 100 to 120 knot mid-level jet is forecast to move into the western Carolinas, as a cold front advances southward across the northern Florida Peninsula. The entrance region of the mid-level jet is forecast to move into the eastern Gulf of Mexico by Wednesday afternoon, strengthening lift and shear across the Florida Peninsula. As storms organize ahead of the front and move eastward across the central Florida Peninsula, the strong deep-layer shear may be enough to support a wind-damage threat with the more intense cells embedded in the convective line. Any severe threat should be the greatest during the mid to late afternoon, as low-level lapse rates become the steepest. A marginal hail threat is also expected. ..Broyles.. 04/02/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Tue Apr 02 2024 Valid 031200Z - 041200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE EASTERN CAROLINAS...MID-ATLANTIC AND FLORIDA PENINSULA... ...SUMMARY... Severe thunderstorms, associated with wind damage and hail, will be possible on Wednesday across parts of the eastern Carolinas and Mid-Atlantic, with a second severe threat area expected over the Florida Peninsula. ...Eastern Carolinas/Mid-Atlantic... A large upper-level low pressure system will move eastward into the southern Great Lakes on Wednesday, as a cold front advances quickly eastward through the southern and central Appalachians. Ahead of the front, a moist airmass will likely be in place across the Carolinas into southeastern Virginia, with surface dewpoints in the 60s F. As surface temperatures warm across the moist airmass, weak instability is expected to develop in most areas during the late morning and early afternoon. While some convection is expected near the front early in the period, new surface-based thunderstorms should develop along and near the moist axis around midday. These storms will likely move eastward across parts of Maryland, eastern Virginia and eastern North Carolina. Forecast soundings during the afternoon along and near the moist axis have extreme deep-layer shear, with 0-6 km shear actually reaching 90 to 100 knots by 21Z. As low-level lapse rates steepen during the day, convection should be able to mix the stronger flow down to the surface, creating a potential for wind damage. The more intense cells could also be associated with an isolated large hail threat, aided by cold temperatures aloft. ...Florida Peninsula... Mid-level flow is forecast to be west-southwesterly across the Gulf Coast states and southern Atlantic Seaboard on Wednesday. A 100 to 120 knot mid-level jet is forecast to move into the western Carolinas, as a cold front advances southward across the northern Florida Peninsula. The entrance region of the mid-level jet is forecast to move into the eastern Gulf of Mexico by Wednesday afternoon, strengthening lift and shear across the Florida Peninsula. As storms organize ahead of the front and move eastward across the central Florida Peninsula, the strong deep-layer shear may be enough to support a wind-damage threat with the more intense cells embedded in the convective line. Any severe threat should be the greatest during the mid to late afternoon, as low-level lapse rates become the steepest. A marginal hail threat is also expected. ..Broyles.. 04/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Tue Apr 02 2024 Valid 021200Z - 031200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY... ...SUMMARY... A potentially substantial severe weather outbreak -- possibly including a few significant/long-track tornadoes -- is anticipated this afternoon and evening, with the highest probability centered over the Ohio Valley. Severe risk exists as far south as the Gulf Coast, and as far east as western portions of Virginia and the Carolinas. ...Discussion... Strong northern-stream upper low, currently located over southern MB, is forecast to drop south across MN into northern IL late in the period. This evolution is driven in part by a 500mb speed max that will translate across the central Plains, increasing to near 100kt over eastern KS/OK by 03/12z. Intense 12hr midlevel height falls are forecast across much of the Great Lakes, OH/TN Valley, and the northern Gulf States, where values in excess of 200m are expected during the latter half of the period. Synoptic front that is currently draped across the OH Valley will be encouraged to gradually advance north due to the digging trough; however, an extensive corridor of convection currently extends across the MS Valley into the OH valley, which is maintaining cool boundary-layer conditions north of I-70. Latest water-vapor imagery suggests a southern-stream short-wave trough is progressing across eastern KS/eastern OK. This feature will progress downstream and likely aid early-day thunderstorm development near the confluence of the MS/OH Rivers. Seasonally high PW airmass currently extends across northern AR/southern MO into southern IL. NAM forecast sounding for JBR at 15z exhibits 60kt surface-6km bulk shear with SBCAPE on the order of 1500 J/kg. Discrete supercells may evolve ahead of this feature then spread/develop northeast across southern IN/KY into OH. Some uncertainty exists across northern OH/IN regarding destabilization. It's not entirely clear if ongoing convection will allow the warm front to lift appreciably north of its current position. However, large-scale pattern is quite dynamic and favors surface low deepening over southern Lake MI during the latter half of the pattern. NAM struggles to reflect this scenario, thus weaker instability is forecast at higher latitudes. Tornadoes, damaging winds, and large hail are expected with supercells that evolve across the warm sector. Some tornadoes may be long-lived and strong. Farther south, a bimodal severe threat may ultimately evolve with a secondary corridor of more concentrated severe across portions of the northern Gulf States. 500mb speed max is forecast to eject across northern Mexico into TX by 03/00z. This feature will intensify as it translates across LA into eastern TN by the end of the period. There is some concern that severe probabilities may need to be increased across this region to account for this low-latitude speed max during the evening/overnight hours. Strong shear will support supercells along with a threat for tornadoes, damaging winds, and hail. ..Darrow/Bentley.. 04/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Tue Apr 02 2024 Valid 021200Z - 031200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY... ...SUMMARY... A potentially substantial severe weather outbreak -- possibly including a few significant/long-track tornadoes -- is anticipated this afternoon and evening, with the highest probability centered over the Ohio Valley. Severe risk exists as far south as the Gulf Coast, and as far east as western portions of Virginia and the Carolinas. ...Discussion... Strong northern-stream upper low, currently located over southern MB, is forecast to drop south across MN into northern IL late in the period. This evolution is driven in part by a 500mb speed max that will translate across the central Plains, increasing to near 100kt over eastern KS/OK by 03/12z. Intense 12hr midlevel height falls are forecast across much of the Great Lakes, OH/TN Valley, and the northern Gulf States, where values in excess of 200m are expected during the latter half of the period. Synoptic front that is currently draped across the OH Valley will be encouraged to gradually advance north due to the digging trough; however, an extensive corridor of convection currently extends across the MS Valley into the OH valley, which is maintaining cool boundary-layer conditions north of I-70. Latest water-vapor imagery suggests a southern-stream short-wave trough is progressing across eastern KS/eastern OK. This feature will progress downstream and likely aid early-day thunderstorm development near the confluence of the MS/OH Rivers. Seasonally high PW airmass currently extends across northern AR/southern MO into southern IL. NAM forecast sounding for JBR at 15z exhibits 60kt surface-6km bulk shear with SBCAPE on the order of 1500 J/kg. Discrete supercells may evolve ahead of this feature then spread/develop northeast across southern IN/KY into OH. Some uncertainty exists across northern OH/IN regarding destabilization. It's not entirely clear if ongoing convection will allow the warm front to lift appreciably north of its current position. However, large-scale pattern is quite dynamic and favors surface low deepening over southern Lake MI during the latter half of the pattern. NAM struggles to reflect this scenario, thus weaker instability is forecast at higher latitudes. Tornadoes, damaging winds, and large hail are expected with supercells that evolve across the warm sector. Some tornadoes may be long-lived and strong. Farther south, a bimodal severe threat may ultimately evolve with a secondary corridor of more concentrated severe across portions of the northern Gulf States. 500mb speed max is forecast to eject across northern Mexico into TX by 03/00z. This feature will intensify as it translates across LA into eastern TN by the end of the period. There is some concern that severe probabilities may need to be increased across this region to account for this low-latitude speed max during the evening/overnight hours. Strong shear will support supercells along with a threat for tornadoes, damaging winds, and hail. ..Darrow/Bentley.. 04/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Tue Apr 02 2024 Valid 021200Z - 031200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY... ...SUMMARY... A potentially substantial severe weather outbreak -- possibly including a few significant/long-track tornadoes -- is anticipated this afternoon and evening, with the highest probability centered over the Ohio Valley. Severe risk exists as far south as the Gulf Coast, and as far east as western portions of Virginia and the Carolinas. ...Discussion... Strong northern-stream upper low, currently located over southern MB, is forecast to drop south across MN into northern IL late in the period. This evolution is driven in part by a 500mb speed max that will translate across the central Plains, increasing to near 100kt over eastern KS/OK by 03/12z. Intense 12hr midlevel height falls are forecast across much of the Great Lakes, OH/TN Valley, and the northern Gulf States, where values in excess of 200m are expected during the latter half of the period. Synoptic front that is currently draped across the OH Valley will be encouraged to gradually advance north due to the digging trough; however, an extensive corridor of convection currently extends across the MS Valley into the OH valley, which is maintaining cool boundary-layer conditions north of I-70. Latest water-vapor imagery suggests a southern-stream short-wave trough is progressing across eastern KS/eastern OK. This feature will progress downstream and likely aid early-day thunderstorm development near the confluence of the MS/OH Rivers. Seasonally high PW airmass currently extends across northern AR/southern MO into southern IL. NAM forecast sounding for JBR at 15z exhibits 60kt surface-6km bulk shear with SBCAPE on the order of 1500 J/kg. Discrete supercells may evolve ahead of this feature then spread/develop northeast across southern IN/KY into OH. Some uncertainty exists across northern OH/IN regarding destabilization. It's not entirely clear if ongoing convection will allow the warm front to lift appreciably north of its current position. However, large-scale pattern is quite dynamic and favors surface low deepening over southern Lake MI during the latter half of the pattern. NAM struggles to reflect this scenario, thus weaker instability is forecast at higher latitudes. Tornadoes, damaging winds, and large hail are expected with supercells that evolve across the warm sector. Some tornadoes may be long-lived and strong. Farther south, a bimodal severe threat may ultimately evolve with a secondary corridor of more concentrated severe across portions of the northern Gulf States. 500mb speed max is forecast to eject across northern Mexico into TX by 03/00z. This feature will intensify as it translates across LA into eastern TN by the end of the period. There is some concern that severe probabilities may need to be increased across this region to account for this low-latitude speed max during the evening/overnight hours. Strong shear will support supercells along with a threat for tornadoes, damaging winds, and hail. ..Darrow/Bentley.. 04/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Tue Apr 02 2024 Valid 021200Z - 031200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY... ...SUMMARY... A potentially substantial severe weather outbreak -- possibly including a few significant/long-track tornadoes -- is anticipated this afternoon and evening, with the highest probability centered over the Ohio Valley. Severe risk exists as far south as the Gulf Coast, and as far east as western portions of Virginia and the Carolinas. ...Discussion... Strong northern-stream upper low, currently located over southern MB, is forecast to drop south across MN into northern IL late in the period. This evolution is driven in part by a 500mb speed max that will translate across the central Plains, increasing to near 100kt over eastern KS/OK by 03/12z. Intense 12hr midlevel height falls are forecast across much of the Great Lakes, OH/TN Valley, and the northern Gulf States, where values in excess of 200m are expected during the latter half of the period. Synoptic front that is currently draped across the OH Valley will be encouraged to gradually advance north due to the digging trough; however, an extensive corridor of convection currently extends across the MS Valley into the OH valley, which is maintaining cool boundary-layer conditions north of I-70. Latest water-vapor imagery suggests a southern-stream short-wave trough is progressing across eastern KS/eastern OK. This feature will progress downstream and likely aid early-day thunderstorm development near the confluence of the MS/OH Rivers. Seasonally high PW airmass currently extends across northern AR/southern MO into southern IL. NAM forecast sounding for JBR at 15z exhibits 60kt surface-6km bulk shear with SBCAPE on the order of 1500 J/kg. Discrete supercells may evolve ahead of this feature then spread/develop northeast across southern IN/KY into OH. Some uncertainty exists across northern OH/IN regarding destabilization. It's not entirely clear if ongoing convection will allow the warm front to lift appreciably north of its current position. However, large-scale pattern is quite dynamic and favors surface low deepening over southern Lake MI during the latter half of the pattern. NAM struggles to reflect this scenario, thus weaker instability is forecast at higher latitudes. Tornadoes, damaging winds, and large hail are expected with supercells that evolve across the warm sector. Some tornadoes may be long-lived and strong. Farther south, a bimodal severe threat may ultimately evolve with a secondary corridor of more concentrated severe across portions of the northern Gulf States. 500mb speed max is forecast to eject across northern Mexico into TX by 03/00z. This feature will intensify as it translates across LA into eastern TN by the end of the period. There is some concern that severe probabilities may need to be increased across this region to account for this low-latitude speed max during the evening/overnight hours. Strong shear will support supercells along with a threat for tornadoes, damaging winds, and hail. ..Darrow/Bentley.. 04/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Tue Apr 02 2024 Valid 021200Z - 031200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY... ...SUMMARY... A potentially substantial severe weather outbreak -- possibly including a few significant/long-track tornadoes -- is anticipated this afternoon and evening, with the highest probability centered over the Ohio Valley. Severe risk exists as far south as the Gulf Coast, and as far east as western portions of Virginia and the Carolinas. ...Discussion... Strong northern-stream upper low, currently located over southern MB, is forecast to drop south across MN into northern IL late in the period. This evolution is driven in part by a 500mb speed max that will translate across the central Plains, increasing to near 100kt over eastern KS/OK by 03/12z. Intense 12hr midlevel height falls are forecast across much of the Great Lakes, OH/TN Valley, and the northern Gulf States, where values in excess of 200m are expected during the latter half of the period. Synoptic front that is currently draped across the OH Valley will be encouraged to gradually advance north due to the digging trough; however, an extensive corridor of convection currently extends across the MS Valley into the OH valley, which is maintaining cool boundary-layer conditions north of I-70. Latest water-vapor imagery suggests a southern-stream short-wave trough is progressing across eastern KS/eastern OK. This feature will progress downstream and likely aid early-day thunderstorm development near the confluence of the MS/OH Rivers. Seasonally high PW airmass currently extends across northern AR/southern MO into southern IL. NAM forecast sounding for JBR at 15z exhibits 60kt surface-6km bulk shear with SBCAPE on the order of 1500 J/kg. Discrete supercells may evolve ahead of this feature then spread/develop northeast across southern IN/KY into OH. Some uncertainty exists across northern OH/IN regarding destabilization. It's not entirely clear if ongoing convection will allow the warm front to lift appreciably north of its current position. However, large-scale pattern is quite dynamic and favors surface low deepening over southern Lake MI during the latter half of the pattern. NAM struggles to reflect this scenario, thus weaker instability is forecast at higher latitudes. Tornadoes, damaging winds, and large hail are expected with supercells that evolve across the warm sector. Some tornadoes may be long-lived and strong. Farther south, a bimodal severe threat may ultimately evolve with a secondary corridor of more concentrated severe across portions of the northern Gulf States. 500mb speed max is forecast to eject across northern Mexico into TX by 03/00z. This feature will intensify as it translates across LA into eastern TN by the end of the period. There is some concern that severe probabilities may need to be increased across this region to account for this low-latitude speed max during the evening/overnight hours. Strong shear will support supercells along with a threat for tornadoes, damaging winds, and hail. ..Darrow/Bentley.. 04/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Tue Apr 02 2024 Valid 021200Z - 031200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY... ...SUMMARY... A potentially substantial severe weather outbreak -- possibly including a few significant/long-track tornadoes -- is anticipated this afternoon and evening, with the highest probability centered over the Ohio Valley. Severe risk exists as far south as the Gulf Coast, and as far east as western portions of Virginia and the Carolinas. ...Discussion... Strong northern-stream upper low, currently located over southern MB, is forecast to drop south across MN into northern IL late in the period. This evolution is driven in part by a 500mb speed max that will translate across the central Plains, increasing to near 100kt over eastern KS/OK by 03/12z. Intense 12hr midlevel height falls are forecast across much of the Great Lakes, OH/TN Valley, and the northern Gulf States, where values in excess of 200m are expected during the latter half of the period. Synoptic front that is currently draped across the OH Valley will be encouraged to gradually advance north due to the digging trough; however, an extensive corridor of convection currently extends across the MS Valley into the OH valley, which is maintaining cool boundary-layer conditions north of I-70. Latest water-vapor imagery suggests a southern-stream short-wave trough is progressing across eastern KS/eastern OK. This feature will progress downstream and likely aid early-day thunderstorm development near the confluence of the MS/OH Rivers. Seasonally high PW airmass currently extends across northern AR/southern MO into southern IL. NAM forecast sounding for JBR at 15z exhibits 60kt surface-6km bulk shear with SBCAPE on the order of 1500 J/kg. Discrete supercells may evolve ahead of this feature then spread/develop northeast across southern IN/KY into OH. Some uncertainty exists across northern OH/IN regarding destabilization. It's not entirely clear if ongoing convection will allow the warm front to lift appreciably north of its current position. However, large-scale pattern is quite dynamic and favors surface low deepening over southern Lake MI during the latter half of the pattern. NAM struggles to reflect this scenario, thus weaker instability is forecast at higher latitudes. Tornadoes, damaging winds, and large hail are expected with supercells that evolve across the warm sector. Some tornadoes may be long-lived and strong. Farther south, a bimodal severe threat may ultimately evolve with a secondary corridor of more concentrated severe across portions of the northern Gulf States. 500mb speed max is forecast to eject across northern Mexico into TX by 03/00z. This feature will intensify as it translates across LA into eastern TN by the end of the period. There is some concern that severe probabilities may need to be increased across this region to account for this low-latitude speed max during the evening/overnight hours. Strong shear will support supercells along with a threat for tornadoes, damaging winds, and hail. ..Darrow/Bentley.. 04/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Tue Apr 02 2024 Valid 021200Z - 031200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY... ...SUMMARY... A potentially substantial severe weather outbreak -- possibly including a few significant/long-track tornadoes -- is anticipated this afternoon and evening, with the highest probability centered over the Ohio Valley. Severe risk exists as far south as the Gulf Coast, and as far east as western portions of Virginia and the Carolinas. ...Discussion... Strong northern-stream upper low, currently located over southern MB, is forecast to drop south across MN into northern IL late in the period. This evolution is driven in part by a 500mb speed max that will translate across the central Plains, increasing to near 100kt over eastern KS/OK by 03/12z. Intense 12hr midlevel height falls are forecast across much of the Great Lakes, OH/TN Valley, and the northern Gulf States, where values in excess of 200m are expected during the latter half of the period. Synoptic front that is currently draped across the OH Valley will be encouraged to gradually advance north due to the digging trough; however, an extensive corridor of convection currently extends across the MS Valley into the OH valley, which is maintaining cool boundary-layer conditions north of I-70. Latest water-vapor imagery suggests a southern-stream short-wave trough is progressing across eastern KS/eastern OK. This feature will progress downstream and likely aid early-day thunderstorm development near the confluence of the MS/OH Rivers. Seasonally high PW airmass currently extends across northern AR/southern MO into southern IL. NAM forecast sounding for JBR at 15z exhibits 60kt surface-6km bulk shear with SBCAPE on the order of 1500 J/kg. Discrete supercells may evolve ahead of this feature then spread/develop northeast across southern IN/KY into OH. Some uncertainty exists across northern OH/IN regarding destabilization. It's not entirely clear if ongoing convection will allow the warm front to lift appreciably north of its current position. However, large-scale pattern is quite dynamic and favors surface low deepening over southern Lake MI during the latter half of the pattern. NAM struggles to reflect this scenario, thus weaker instability is forecast at higher latitudes. Tornadoes, damaging winds, and large hail are expected with supercells that evolve across the warm sector. Some tornadoes may be long-lived and strong. Farther south, a bimodal severe threat may ultimately evolve with a secondary corridor of more concentrated severe across portions of the northern Gulf States. 500mb speed max is forecast to eject across northern Mexico into TX by 03/00z. This feature will intensify as it translates across LA into eastern TN by the end of the period. There is some concern that severe probabilities may need to be increased across this region to account for this low-latitude speed max during the evening/overnight hours. Strong shear will support supercells along with a threat for tornadoes, damaging winds, and hail. ..Darrow/Bentley.. 04/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Tue Apr 02 2024 Valid 021200Z - 031200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY... ...SUMMARY... A potentially substantial severe weather outbreak -- possibly including a few significant/long-track tornadoes -- is anticipated this afternoon and evening, with the highest probability centered over the Ohio Valley. Severe risk exists as far south as the Gulf Coast, and as far east as western portions of Virginia and the Carolinas. ...Discussion... Strong northern-stream upper low, currently located over southern MB, is forecast to drop south across MN into northern IL late in the period. This evolution is driven in part by a 500mb speed max that will translate across the central Plains, increasing to near 100kt over eastern KS/OK by 03/12z. Intense 12hr midlevel height falls are forecast across much of the Great Lakes, OH/TN Valley, and the northern Gulf States, where values in excess of 200m are expected during the latter half of the period. Synoptic front that is currently draped across the OH Valley will be encouraged to gradually advance north due to the digging trough; however, an extensive corridor of convection currently extends across the MS Valley into the OH valley, which is maintaining cool boundary-layer conditions north of I-70. Latest water-vapor imagery suggests a southern-stream short-wave trough is progressing across eastern KS/eastern OK. This feature will progress downstream and likely aid early-day thunderstorm development near the confluence of the MS/OH Rivers. Seasonally high PW airmass currently extends across northern AR/southern MO into southern IL. NAM forecast sounding for JBR at 15z exhibits 60kt surface-6km bulk shear with SBCAPE on the order of 1500 J/kg. Discrete supercells may evolve ahead of this feature then spread/develop northeast across southern IN/KY into OH. Some uncertainty exists across northern OH/IN regarding destabilization. It's not entirely clear if ongoing convection will allow the warm front to lift appreciably north of its current position. However, large-scale pattern is quite dynamic and favors surface low deepening over southern Lake MI during the latter half of the pattern. NAM struggles to reflect this scenario, thus weaker instability is forecast at higher latitudes. Tornadoes, damaging winds, and large hail are expected with supercells that evolve across the warm sector. Some tornadoes may be long-lived and strong. Farther south, a bimodal severe threat may ultimately evolve with a secondary corridor of more concentrated severe across portions of the northern Gulf States. 500mb speed max is forecast to eject across northern Mexico into TX by 03/00z. This feature will intensify as it translates across LA into eastern TN by the end of the period. There is some concern that severe probabilities may need to be increased across this region to account for this low-latitude speed max during the evening/overnight hours. Strong shear will support supercells along with a threat for tornadoes, damaging winds, and hail. ..Darrow/Bentley.. 04/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Tue Apr 02 2024 Valid 021200Z - 031200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY... ...SUMMARY... A potentially substantial severe weather outbreak -- possibly including a few significant/long-track tornadoes -- is anticipated this afternoon and evening, with the highest probability centered over the Ohio Valley. Severe risk exists as far south as the Gulf Coast, and as far east as western portions of Virginia and the Carolinas. ...Discussion... Strong northern-stream upper low, currently located over southern MB, is forecast to drop south across MN into northern IL late in the period. This evolution is driven in part by a 500mb speed max that will translate across the central Plains, increasing to near 100kt over eastern KS/OK by 03/12z. Intense 12hr midlevel height falls are forecast across much of the Great Lakes, OH/TN Valley, and the northern Gulf States, where values in excess of 200m are expected during the latter half of the period. Synoptic front that is currently draped across the OH Valley will be encouraged to gradually advance north due to the digging trough; however, an extensive corridor of convection currently extends across the MS Valley into the OH valley, which is maintaining cool boundary-layer conditions north of I-70. Latest water-vapor imagery suggests a southern-stream short-wave trough is progressing across eastern KS/eastern OK. This feature will progress downstream and likely aid early-day thunderstorm development near the confluence of the MS/OH Rivers. Seasonally high PW airmass currently extends across northern AR/southern MO into southern IL. NAM forecast sounding for JBR at 15z exhibits 60kt surface-6km bulk shear with SBCAPE on the order of 1500 J/kg. Discrete supercells may evolve ahead of this feature then spread/develop northeast across southern IN/KY into OH. Some uncertainty exists across northern OH/IN regarding destabilization. It's not entirely clear if ongoing convection will allow the warm front to lift appreciably north of its current position. However, large-scale pattern is quite dynamic and favors surface low deepening over southern Lake MI during the latter half of the pattern. NAM struggles to reflect this scenario, thus weaker instability is forecast at higher latitudes. Tornadoes, damaging winds, and large hail are expected with supercells that evolve across the warm sector. Some tornadoes may be long-lived and strong. Farther south, a bimodal severe threat may ultimately evolve with a secondary corridor of more concentrated severe across portions of the northern Gulf States. 500mb speed max is forecast to eject across northern Mexico into TX by 03/00z. This feature will intensify as it translates across LA into eastern TN by the end of the period. There is some concern that severe probabilities may need to be increased across this region to account for this low-latitude speed max during the evening/overnight hours. Strong shear will support supercells along with a threat for tornadoes, damaging winds, and hail. ..Darrow/Bentley.. 04/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Tue Apr 02 2024 Valid 021200Z - 031200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY... ...SUMMARY... A potentially substantial severe weather outbreak -- possibly including a few significant/long-track tornadoes -- is anticipated this afternoon and evening, with the highest probability centered over the Ohio Valley. Severe risk exists as far south as the Gulf Coast, and as far east as western portions of Virginia and the Carolinas. ...Discussion... Strong northern-stream upper low, currently located over southern MB, is forecast to drop south across MN into northern IL late in the period. This evolution is driven in part by a 500mb speed max that will translate across the central Plains, increasing to near 100kt over eastern KS/OK by 03/12z. Intense 12hr midlevel height falls are forecast across much of the Great Lakes, OH/TN Valley, and the northern Gulf States, where values in excess of 200m are expected during the latter half of the period. Synoptic front that is currently draped across the OH Valley will be encouraged to gradually advance north due to the digging trough; however, an extensive corridor of convection currently extends across the MS Valley into the OH valley, which is maintaining cool boundary-layer conditions north of I-70. Latest water-vapor imagery suggests a southern-stream short-wave trough is progressing across eastern KS/eastern OK. This feature will progress downstream and likely aid early-day thunderstorm development near the confluence of the MS/OH Rivers. Seasonally high PW airmass currently extends across northern AR/southern MO into southern IL. NAM forecast sounding for JBR at 15z exhibits 60kt surface-6km bulk shear with SBCAPE on the order of 1500 J/kg. Discrete supercells may evolve ahead of this feature then spread/develop northeast across southern IN/KY into OH. Some uncertainty exists across northern OH/IN regarding destabilization. It's not entirely clear if ongoing convection will allow the warm front to lift appreciably north of its current position. However, large-scale pattern is quite dynamic and favors surface low deepening over southern Lake MI during the latter half of the pattern. NAM struggles to reflect this scenario, thus weaker instability is forecast at higher latitudes. Tornadoes, damaging winds, and large hail are expected with supercells that evolve across the warm sector. Some tornadoes may be long-lived and strong. Farther south, a bimodal severe threat may ultimately evolve with a secondary corridor of more concentrated severe across portions of the northern Gulf States. 500mb speed max is forecast to eject across northern Mexico into TX by 03/00z. This feature will intensify as it translates across LA into eastern TN by the end of the period. There is some concern that severe probabilities may need to be increased across this region to account for this low-latitude speed max during the evening/overnight hours. Strong shear will support supercells along with a threat for tornadoes, damaging winds, and hail. ..Darrow/Bentley.. 04/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Tue Apr 02 2024 Valid 021200Z - 031200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY... ...SUMMARY... A potentially substantial severe weather outbreak -- possibly including a few significant/long-track tornadoes -- is anticipated this afternoon and evening, with the highest probability centered over the Ohio Valley. Severe risk exists as far south as the Gulf Coast, and as far east as western portions of Virginia and the Carolinas. ...Discussion... Strong northern-stream upper low, currently located over southern MB, is forecast to drop south across MN into northern IL late in the period. This evolution is driven in part by a 500mb speed max that will translate across the central Plains, increasing to near 100kt over eastern KS/OK by 03/12z. Intense 12hr midlevel height falls are forecast across much of the Great Lakes, OH/TN Valley, and the northern Gulf States, where values in excess of 200m are expected during the latter half of the period. Synoptic front that is currently draped across the OH Valley will be encouraged to gradually advance north due to the digging trough; however, an extensive corridor of convection currently extends across the MS Valley into the OH valley, which is maintaining cool boundary-layer conditions north of I-70. Latest water-vapor imagery suggests a southern-stream short-wave trough is progressing across eastern KS/eastern OK. This feature will progress downstream and likely aid early-day thunderstorm development near the confluence of the MS/OH Rivers. Seasonally high PW airmass currently extends across northern AR/southern MO into southern IL. NAM forecast sounding for JBR at 15z exhibits 60kt surface-6km bulk shear with SBCAPE on the order of 1500 J/kg. Discrete supercells may evolve ahead of this feature then spread/develop northeast across southern IN/KY into OH. Some uncertainty exists across northern OH/IN regarding destabilization. It's not entirely clear if ongoing convection will allow the warm front to lift appreciably north of its current position. However, large-scale pattern is quite dynamic and favors surface low deepening over southern Lake MI during the latter half of the pattern. NAM struggles to reflect this scenario, thus weaker instability is forecast at higher latitudes. Tornadoes, damaging winds, and large hail are expected with supercells that evolve across the warm sector. Some tornadoes may be long-lived and strong. Farther south, a bimodal severe threat may ultimately evolve with a secondary corridor of more concentrated severe across portions of the northern Gulf States. 500mb speed max is forecast to eject across northern Mexico into TX by 03/00z. This feature will intensify as it translates across LA into eastern TN by the end of the period. There is some concern that severe probabilities may need to be increased across this region to account for this low-latitude speed max during the evening/overnight hours. Strong shear will support supercells along with a threat for tornadoes, damaging winds, and hail. ..Darrow/Bentley.. 04/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Tue Apr 02 2024 Valid 021200Z - 031200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY... ...SUMMARY... A potentially substantial severe weather outbreak -- possibly including a few significant/long-track tornadoes -- is anticipated this afternoon and evening, with the highest probability centered over the Ohio Valley. Severe risk exists as far south as the Gulf Coast, and as far east as western portions of Virginia and the Carolinas. ...Discussion... Strong northern-stream upper low, currently located over southern MB, is forecast to drop south across MN into northern IL late in the period. This evolution is driven in part by a 500mb speed max that will translate across the central Plains, increasing to near 100kt over eastern KS/OK by 03/12z. Intense 12hr midlevel height falls are forecast across much of the Great Lakes, OH/TN Valley, and the northern Gulf States, where values in excess of 200m are expected during the latter half of the period. Synoptic front that is currently draped across the OH Valley will be encouraged to gradually advance north due to the digging trough; however, an extensive corridor of convection currently extends across the MS Valley into the OH valley, which is maintaining cool boundary-layer conditions north of I-70. Latest water-vapor imagery suggests a southern-stream short-wave trough is progressing across eastern KS/eastern OK. This feature will progress downstream and likely aid early-day thunderstorm development near the confluence of the MS/OH Rivers. Seasonally high PW airmass currently extends across northern AR/southern MO into southern IL. NAM forecast sounding for JBR at 15z exhibits 60kt surface-6km bulk shear with SBCAPE on the order of 1500 J/kg. Discrete supercells may evolve ahead of this feature then spread/develop northeast across southern IN/KY into OH. Some uncertainty exists across northern OH/IN regarding destabilization. It's not entirely clear if ongoing convection will allow the warm front to lift appreciably north of its current position. However, large-scale pattern is quite dynamic and favors surface low deepening over southern Lake MI during the latter half of the pattern. NAM struggles to reflect this scenario, thus weaker instability is forecast at higher latitudes. Tornadoes, damaging winds, and large hail are expected with supercells that evolve across the warm sector. Some tornadoes may be long-lived and strong. Farther south, a bimodal severe threat may ultimately evolve with a secondary corridor of more concentrated severe across portions of the northern Gulf States. 500mb speed max is forecast to eject across northern Mexico into TX by 03/00z. This feature will intensify as it translates across LA into eastern TN by the end of the period. There is some concern that severe probabilities may need to be increased across this region to account for this low-latitude speed max during the evening/overnight hours. Strong shear will support supercells along with a threat for tornadoes, damaging winds, and hail. ..Darrow/Bentley.. 04/02/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Tue Apr 02 2024 Valid 021200Z - 031200Z ...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS THE OHIO VALLEY... ...SUMMARY... A potentially substantial severe weather outbreak -- possibly including a few significant/long-track tornadoes -- is anticipated this afternoon and evening, with the highest probability centered over the Ohio Valley. Severe risk exists as far south as the Gulf Coast, and as far east as western portions of Virginia and the Carolinas. ...Discussion... Strong northern-stream upper low, currently located over southern MB, is forecast to drop south across MN into northern IL late in the period. This evolution is driven in part by a 500mb speed max that will translate across the central Plains, increasing to near 100kt over eastern KS/OK by 03/12z. Intense 12hr midlevel height falls are forecast across much of the Great Lakes, OH/TN Valley, and the northern Gulf States, where values in excess of 200m are expected during the latter half of the period. Synoptic front that is currently draped across the OH Valley will be encouraged to gradually advance north due to the digging trough; however, an extensive corridor of convection currently extends across the MS Valley into the OH valley, which is maintaining cool boundary-layer conditions north of I-70. Latest water-vapor imagery suggests a southern-stream short-wave trough is progressing across eastern KS/eastern OK. This feature will progress downstream and likely aid early-day thunderstorm development near the confluence of the MS/OH Rivers. Seasonally high PW airmass currently extends across northern AR/southern MO into southern IL. NAM forecast sounding for JBR at 15z exhibits 60kt surface-6km bulk shear with SBCAPE on the order of 1500 J/kg. Discrete supercells may evolve ahead of this feature then spread/develop northeast across southern IN/KY into OH. Some uncertainty exists across northern OH/IN regarding destabilization. It's not entirely clear if ongoing convection will allow the warm front to lift appreciably north of its current position. However, large-scale pattern is quite dynamic and favors surface low deepening over southern Lake MI during the latter half of the pattern. NAM struggles to reflect this scenario, thus weaker instability is forecast at higher latitudes. Tornadoes, damaging winds, and large hail are expected with supercells that evolve across the warm sector. Some tornadoes may be long-lived and strong. Farther south, a bimodal severe threat may ultimately evolve with a secondary corridor of more concentrated severe across portions of the northern Gulf States. 500mb speed max is forecast to eject across northern Mexico into TX by 03/00z. This feature will intensify as it translates across LA into eastern TN by the end of the period. There is some concern that severe probabilities may need to be increased across this region to account for this low-latitude speed max during the evening/overnight hours. Strong shear will support supercells along with a threat for tornadoes, damaging winds, and hail. ..Darrow/Bentley.. 04/02/2024 Read more