Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0137 AM CDT Sun Mar 24 2024 Valid 241200Z - 251200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE CENTRAL AND SOUTHERN HIGH PLAINS... ...Synopsis... Rapid surface cyclone intensification should occur across the Plains states as a mid-level trough deepens while ejecting into the central CONUS today. In tandem with the strong surface cyclone, a dryline will rapidly surge across the central and southern High Plains, with very dry and windy conditions occurring in its wake. Latest guidance consensus shows 30+ mph sustained westerly surface winds (with gusts approaching 50 mph) coinciding with 15-25 percent RH during the afternoon behind the dryline. Given the loading of drying fine fuels across the central and southern High Plains, dangerous wildfire-spread conditions will manifest sometime during the late morning and persist into the early evening hours. As such, "high-end" Critical fire weather highlights have been maintained. The potential for fire ignitions will also be exacerbated by the possibility of dry thunderstorms (albeit sparse in coverage) across portions of the central and southern High Plains, where isolated dry thunderstorm highlights have been introduced. Forecast soundings from multiple guidance members show classic inverted-v soundings amid strong tropospheric flow, which will be ideal for high-based, fast-moving thunderstorms atop loaded fine fuels, should updraft development become robust and persistent. ..Squitieri.. 03/24/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0137 AM CDT Sun Mar 24 2024 Valid 241200Z - 251200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE CENTRAL AND SOUTHERN HIGH PLAINS... ...Synopsis... Rapid surface cyclone intensification should occur across the Plains states as a mid-level trough deepens while ejecting into the central CONUS today. In tandem with the strong surface cyclone, a dryline will rapidly surge across the central and southern High Plains, with very dry and windy conditions occurring in its wake. Latest guidance consensus shows 30+ mph sustained westerly surface winds (with gusts approaching 50 mph) coinciding with 15-25 percent RH during the afternoon behind the dryline. Given the loading of drying fine fuels across the central and southern High Plains, dangerous wildfire-spread conditions will manifest sometime during the late morning and persist into the early evening hours. As such, "high-end" Critical fire weather highlights have been maintained. The potential for fire ignitions will also be exacerbated by the possibility of dry thunderstorms (albeit sparse in coverage) across portions of the central and southern High Plains, where isolated dry thunderstorm highlights have been introduced. Forecast soundings from multiple guidance members show classic inverted-v soundings amid strong tropospheric flow, which will be ideal for high-based, fast-moving thunderstorms atop loaded fine fuels, should updraft development become robust and persistent. ..Squitieri.. 03/24/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1252 AM CDT Sun Mar 24 2024 Valid 251200Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EAST TEXAS INTO THE LOWER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe thunderstorms with a threat for a few tornadoes and damaging winds should occur Monday through Monday night from parts of east Texas into the lower Mississippi Valley. ...Synopsis... A highly amplified upper trough will be present over much of the central CONUS into northern Mexico on Monday. Multiple embedded mid-level perturbations should exist within the larger upper trough. One such shortwave trough is forecast to move across the Upper Midwest through the day, and another over northern Mexico and the southern High Plains should eject towards the lower/mid MS Valley through the period. The primary surface low should be located over eastern NE/KS Monday morning, and it is forecast to develop east-northeastward across the Upper Midwest by Monday evening. A weak, secondary surface low may develop across the ArkLaTex and move towards the Mid-South through Monday night as strong ascent associated with the southern/basal portion of the upper trough overspreads the lower MS Valley. ...East Texas into the Lower Mississippi Valley... A line of generally sub-severe thunderstorms will likely be ongoing Monday morning from portions of central TX into eastern OK and the Ozarks. Strong low-level mass response associated with a southerly low-level jet is expected to aid in the northward transport of generally mid to upper 60s surface dewpoints across parts of the lower MS Valley ahead of the early-day convection. Even though mid-level lapse rates should remain rather poor, the increasing low-level moisture combined with modest daytime heating should support the development of weak instability by early Monday afternoon. A gradual uptick in convective coverage and intensity is anticipated Monday afternoon/evening across LA/southern AR and into MS as these thunderstorms encounter somewhat greater instability. Enhanced mid/upper-level flow attendant to the upper trough will easily support 45-60 kt of deep-layer shear and robust updraft organization. Scattered damaging winds should be the main threat with the line of intensifying convection as it moves eastward across the lower MS Valley, although low-level shear also appears strong enough to support line-embedded/QLCS tornadoes. The potential for pre-frontal supercells developing along a weak surface trough or confluence lines remains highly uncertain. Most high-resolution guidance suggests that the QLCS should maintain its intensity, and perhaps even strengthen Monday evening/night across MS as a southerly low-level jet increases to around 45-60 kt. A narrow corridor of greater severe/damaging-wind potential may exist across parts of northeastern LA/southeastern AR into central MS along and just south of the effective warm front. However, confidence in this scenario occurring is not high enough to include greater severe-wind probabilities at this time. A nocturnal tornado threat should continue with the organized QLCS as it moves across MS and towards western AL Monday night through early Tuesday morning, eventually weakening as it encounters a less unstable airmass with eastward extent. ...Western Iowa and Vicinity... Within the larger-scale upper trough over the central states, an embedded, cold-core mid-level shortwave trough will move quickly northeastward across the Upper Midwest Monday. Even though low-level moisture should remain quite limited, most guidance shows low 50s surface dewpoints present near a deep surface low across western IA and vicinity Monday afternoon. Just modest daytime heating will support weak destabilization given the cold mid-level temperatures, and deep-layer shear appears strong enough for somewhat organized thunderstorms. Isolated/marginally severe hail and strong/gusty winds may occur with any sustained low-topped convection. Based on latest guidance trends, the Marginal Risk has been adjusted westward in IA where a better signal for modest destabilization exists Monday afternoon. ..Gleason.. 03/24/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1252 AM CDT Sun Mar 24 2024 Valid 251200Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EAST TEXAS INTO THE LOWER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe thunderstorms with a threat for a few tornadoes and damaging winds should occur Monday through Monday night from parts of east Texas into the lower Mississippi Valley. ...Synopsis... A highly amplified upper trough will be present over much of the central CONUS into northern Mexico on Monday. Multiple embedded mid-level perturbations should exist within the larger upper trough. One such shortwave trough is forecast to move across the Upper Midwest through the day, and another over northern Mexico and the southern High Plains should eject towards the lower/mid MS Valley through the period. The primary surface low should be located over eastern NE/KS Monday morning, and it is forecast to develop east-northeastward across the Upper Midwest by Monday evening. A weak, secondary surface low may develop across the ArkLaTex and move towards the Mid-South through Monday night as strong ascent associated with the southern/basal portion of the upper trough overspreads the lower MS Valley. ...East Texas into the Lower Mississippi Valley... A line of generally sub-severe thunderstorms will likely be ongoing Monday morning from portions of central TX into eastern OK and the Ozarks. Strong low-level mass response associated with a southerly low-level jet is expected to aid in the northward transport of generally mid to upper 60s surface dewpoints across parts of the lower MS Valley ahead of the early-day convection. Even though mid-level lapse rates should remain rather poor, the increasing low-level moisture combined with modest daytime heating should support the development of weak instability by early Monday afternoon. A gradual uptick in convective coverage and intensity is anticipated Monday afternoon/evening across LA/southern AR and into MS as these thunderstorms encounter somewhat greater instability. Enhanced mid/upper-level flow attendant to the upper trough will easily support 45-60 kt of deep-layer shear and robust updraft organization. Scattered damaging winds should be the main threat with the line of intensifying convection as it moves eastward across the lower MS Valley, although low-level shear also appears strong enough to support line-embedded/QLCS tornadoes. The potential for pre-frontal supercells developing along a weak surface trough or confluence lines remains highly uncertain. Most high-resolution guidance suggests that the QLCS should maintain its intensity, and perhaps even strengthen Monday evening/night across MS as a southerly low-level jet increases to around 45-60 kt. A narrow corridor of greater severe/damaging-wind potential may exist across parts of northeastern LA/southeastern AR into central MS along and just south of the effective warm front. However, confidence in this scenario occurring is not high enough to include greater severe-wind probabilities at this time. A nocturnal tornado threat should continue with the organized QLCS as it moves across MS and towards western AL Monday night through early Tuesday morning, eventually weakening as it encounters a less unstable airmass with eastward extent. ...Western Iowa and Vicinity... Within the larger-scale upper trough over the central states, an embedded, cold-core mid-level shortwave trough will move quickly northeastward across the Upper Midwest Monday. Even though low-level moisture should remain quite limited, most guidance shows low 50s surface dewpoints present near a deep surface low across western IA and vicinity Monday afternoon. Just modest daytime heating will support weak destabilization given the cold mid-level temperatures, and deep-layer shear appears strong enough for somewhat organized thunderstorms. Isolated/marginally severe hail and strong/gusty winds may occur with any sustained low-topped convection. Based on latest guidance trends, the Marginal Risk has been adjusted westward in IA where a better signal for modest destabilization exists Monday afternoon. ..Gleason.. 03/24/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1252 AM CDT Sun Mar 24 2024 Valid 251200Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EAST TEXAS INTO THE LOWER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe thunderstorms with a threat for a few tornadoes and damaging winds should occur Monday through Monday night from parts of east Texas into the lower Mississippi Valley. ...Synopsis... A highly amplified upper trough will be present over much of the central CONUS into northern Mexico on Monday. Multiple embedded mid-level perturbations should exist within the larger upper trough. One such shortwave trough is forecast to move across the Upper Midwest through the day, and another over northern Mexico and the southern High Plains should eject towards the lower/mid MS Valley through the period. The primary surface low should be located over eastern NE/KS Monday morning, and it is forecast to develop east-northeastward across the Upper Midwest by Monday evening. A weak, secondary surface low may develop across the ArkLaTex and move towards the Mid-South through Monday night as strong ascent associated with the southern/basal portion of the upper trough overspreads the lower MS Valley. ...East Texas into the Lower Mississippi Valley... A line of generally sub-severe thunderstorms will likely be ongoing Monday morning from portions of central TX into eastern OK and the Ozarks. Strong low-level mass response associated with a southerly low-level jet is expected to aid in the northward transport of generally mid to upper 60s surface dewpoints across parts of the lower MS Valley ahead of the early-day convection. Even though mid-level lapse rates should remain rather poor, the increasing low-level moisture combined with modest daytime heating should support the development of weak instability by early Monday afternoon. A gradual uptick in convective coverage and intensity is anticipated Monday afternoon/evening across LA/southern AR and into MS as these thunderstorms encounter somewhat greater instability. Enhanced mid/upper-level flow attendant to the upper trough will easily support 45-60 kt of deep-layer shear and robust updraft organization. Scattered damaging winds should be the main threat with the line of intensifying convection as it moves eastward across the lower MS Valley, although low-level shear also appears strong enough to support line-embedded/QLCS tornadoes. The potential for pre-frontal supercells developing along a weak surface trough or confluence lines remains highly uncertain. Most high-resolution guidance suggests that the QLCS should maintain its intensity, and perhaps even strengthen Monday evening/night across MS as a southerly low-level jet increases to around 45-60 kt. A narrow corridor of greater severe/damaging-wind potential may exist across parts of northeastern LA/southeastern AR into central MS along and just south of the effective warm front. However, confidence in this scenario occurring is not high enough to include greater severe-wind probabilities at this time. A nocturnal tornado threat should continue with the organized QLCS as it moves across MS and towards western AL Monday night through early Tuesday morning, eventually weakening as it encounters a less unstable airmass with eastward extent. ...Western Iowa and Vicinity... Within the larger-scale upper trough over the central states, an embedded, cold-core mid-level shortwave trough will move quickly northeastward across the Upper Midwest Monday. Even though low-level moisture should remain quite limited, most guidance shows low 50s surface dewpoints present near a deep surface low across western IA and vicinity Monday afternoon. Just modest daytime heating will support weak destabilization given the cold mid-level temperatures, and deep-layer shear appears strong enough for somewhat organized thunderstorms. Isolated/marginally severe hail and strong/gusty winds may occur with any sustained low-topped convection. Based on latest guidance trends, the Marginal Risk has been adjusted westward in IA where a better signal for modest destabilization exists Monday afternoon. ..Gleason.. 03/24/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1252 AM CDT Sun Mar 24 2024 Valid 251200Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EAST TEXAS INTO THE LOWER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe thunderstorms with a threat for a few tornadoes and damaging winds should occur Monday through Monday night from parts of east Texas into the lower Mississippi Valley. ...Synopsis... A highly amplified upper trough will be present over much of the central CONUS into northern Mexico on Monday. Multiple embedded mid-level perturbations should exist within the larger upper trough. One such shortwave trough is forecast to move across the Upper Midwest through the day, and another over northern Mexico and the southern High Plains should eject towards the lower/mid MS Valley through the period. The primary surface low should be located over eastern NE/KS Monday morning, and it is forecast to develop east-northeastward across the Upper Midwest by Monday evening. A weak, secondary surface low may develop across the ArkLaTex and move towards the Mid-South through Monday night as strong ascent associated with the southern/basal portion of the upper trough overspreads the lower MS Valley. ...East Texas into the Lower Mississippi Valley... A line of generally sub-severe thunderstorms will likely be ongoing Monday morning from portions of central TX into eastern OK and the Ozarks. Strong low-level mass response associated with a southerly low-level jet is expected to aid in the northward transport of generally mid to upper 60s surface dewpoints across parts of the lower MS Valley ahead of the early-day convection. Even though mid-level lapse rates should remain rather poor, the increasing low-level moisture combined with modest daytime heating should support the development of weak instability by early Monday afternoon. A gradual uptick in convective coverage and intensity is anticipated Monday afternoon/evening across LA/southern AR and into MS as these thunderstorms encounter somewhat greater instability. Enhanced mid/upper-level flow attendant to the upper trough will easily support 45-60 kt of deep-layer shear and robust updraft organization. Scattered damaging winds should be the main threat with the line of intensifying convection as it moves eastward across the lower MS Valley, although low-level shear also appears strong enough to support line-embedded/QLCS tornadoes. The potential for pre-frontal supercells developing along a weak surface trough or confluence lines remains highly uncertain. Most high-resolution guidance suggests that the QLCS should maintain its intensity, and perhaps even strengthen Monday evening/night across MS as a southerly low-level jet increases to around 45-60 kt. A narrow corridor of greater severe/damaging-wind potential may exist across parts of northeastern LA/southeastern AR into central MS along and just south of the effective warm front. However, confidence in this scenario occurring is not high enough to include greater severe-wind probabilities at this time. A nocturnal tornado threat should continue with the organized QLCS as it moves across MS and towards western AL Monday night through early Tuesday morning, eventually weakening as it encounters a less unstable airmass with eastward extent. ...Western Iowa and Vicinity... Within the larger-scale upper trough over the central states, an embedded, cold-core mid-level shortwave trough will move quickly northeastward across the Upper Midwest Monday. Even though low-level moisture should remain quite limited, most guidance shows low 50s surface dewpoints present near a deep surface low across western IA and vicinity Monday afternoon. Just modest daytime heating will support weak destabilization given the cold mid-level temperatures, and deep-layer shear appears strong enough for somewhat organized thunderstorms. Isolated/marginally severe hail and strong/gusty winds may occur with any sustained low-topped convection. Based on latest guidance trends, the Marginal Risk has been adjusted westward in IA where a better signal for modest destabilization exists Monday afternoon. ..Gleason.. 03/24/2024 Read more

SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1252 AM CDT Sun Mar 24 2024 Valid 251200Z - 261200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF EAST TEXAS INTO THE LOWER MISSISSIPPI VALLEY... ...SUMMARY... Scattered severe thunderstorms with a threat for a few tornadoes and damaging winds should occur Monday through Monday night from parts of east Texas into the lower Mississippi Valley. ...Synopsis... A highly amplified upper trough will be present over much of the central CONUS into northern Mexico on Monday. Multiple embedded mid-level perturbations should exist within the larger upper trough. One such shortwave trough is forecast to move across the Upper Midwest through the day, and another over northern Mexico and the southern High Plains should eject towards the lower/mid MS Valley through the period. The primary surface low should be located over eastern NE/KS Monday morning, and it is forecast to develop east-northeastward across the Upper Midwest by Monday evening. A weak, secondary surface low may develop across the ArkLaTex and move towards the Mid-South through Monday night as strong ascent associated with the southern/basal portion of the upper trough overspreads the lower MS Valley. ...East Texas into the Lower Mississippi Valley... A line of generally sub-severe thunderstorms will likely be ongoing Monday morning from portions of central TX into eastern OK and the Ozarks. Strong low-level mass response associated with a southerly low-level jet is expected to aid in the northward transport of generally mid to upper 60s surface dewpoints across parts of the lower MS Valley ahead of the early-day convection. Even though mid-level lapse rates should remain rather poor, the increasing low-level moisture combined with modest daytime heating should support the development of weak instability by early Monday afternoon. A gradual uptick in convective coverage and intensity is anticipated Monday afternoon/evening across LA/southern AR and into MS as these thunderstorms encounter somewhat greater instability. Enhanced mid/upper-level flow attendant to the upper trough will easily support 45-60 kt of deep-layer shear and robust updraft organization. Scattered damaging winds should be the main threat with the line of intensifying convection as it moves eastward across the lower MS Valley, although low-level shear also appears strong enough to support line-embedded/QLCS tornadoes. The potential for pre-frontal supercells developing along a weak surface trough or confluence lines remains highly uncertain. Most high-resolution guidance suggests that the QLCS should maintain its intensity, and perhaps even strengthen Monday evening/night across MS as a southerly low-level jet increases to around 45-60 kt. A narrow corridor of greater severe/damaging-wind potential may exist across parts of northeastern LA/southeastern AR into central MS along and just south of the effective warm front. However, confidence in this scenario occurring is not high enough to include greater severe-wind probabilities at this time. A nocturnal tornado threat should continue with the organized QLCS as it moves across MS and towards western AL Monday night through early Tuesday morning, eventually weakening as it encounters a less unstable airmass with eastward extent. ...Western Iowa and Vicinity... Within the larger-scale upper trough over the central states, an embedded, cold-core mid-level shortwave trough will move quickly northeastward across the Upper Midwest Monday. Even though low-level moisture should remain quite limited, most guidance shows low 50s surface dewpoints present near a deep surface low across western IA and vicinity Monday afternoon. Just modest daytime heating will support weak destabilization given the cold mid-level temperatures, and deep-layer shear appears strong enough for somewhat organized thunderstorms. Isolated/marginally severe hail and strong/gusty winds may occur with any sustained low-topped convection. Based on latest guidance trends, the Marginal Risk has been adjusted westward in IA where a better signal for modest destabilization exists Monday afternoon. ..Gleason.. 03/24/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Sun Mar 24 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL/SOUTHERN PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms should develop this afternoon and persist through Sunday night across parts of the southern/central Plains. Large hail and a few tornadoes are expected to be the main threats, but occasional severe winds may also occur. ...Central/Southern Plains... Strong southern-stream short-wave trough is forecast to shift across northwest Mexico early in the period, then eject into the southern High Plains during the afternoon. In response to this feature, lee surface low will deepen over southeast CO before ejecting into southwest KS during the evening. As should be expected, LLJ will increase markedly across the southern/central Plains, which will encourage boundary-layer moisture to advance north across OK into KS. Early this morning, leading edge of 50F surface dewpoints are located over southern OK. This air mass may spread as far north as I-70 by 25/00z, with upper 40s dewpoints likely being drawn toward the CO border, just north of the surface low. Strong boundary-layer heating will be noted across the High Plains of west TX into extreme southwest KS. As a result, convective temperatures will likely be breached by 20z within the exit region of a midlevel jet, where 500mb temperatures are forecast to cool below -20C. Very steep lapse rates and cold profiles will result in ample buoyancy for robust updrafts. Latest thinking is warm advection may generate some early-day elevated convection east of the dryline, but this activity will spread east and the focus for severe will be across the High Plains during peak heating. Scattered supercells are expected to develop immediately ahead of the surface low/dryline within a very dynamically forced environment. While surface dew points may never rise above the mid 50s downstream of this activity, surface-based buoyancy is expected to develop by late evening as far east as the I35 corridor as temperatures aloft cool. Large hail should be common with supercells, and some tornado threat also exists given the strong shear and surface-based nature of this activity. Convection will spread/develop east during the overnight hours as the upper trough progresses downstream. Farther south across TX, convection may initially struggle to develop along the dryline due to warmer midlevel temperatures and some CINH. However, significant midlevel cooling will be noted after 25/00z and profiles should adjust and become favorable for convective development. Latest model guidance, including the HREF, suggest this activity may be more linear in nature, though strongly sheared. Forward-propagating squall line may advance across TX and southern OK during the overnight hours, with an attendant risk for gusty winds, some hail and/or a brief tornado. The coverage of severe may remain a bit too isolated to warrant a SLGT risk, but this will be monitored and adjusted as conditions warrant. ..Darrow/Squitieri.. 03/24/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Sun Mar 24 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL/SOUTHERN PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms should develop this afternoon and persist through Sunday night across parts of the southern/central Plains. Large hail and a few tornadoes are expected to be the main threats, but occasional severe winds may also occur. ...Central/Southern Plains... Strong southern-stream short-wave trough is forecast to shift across northwest Mexico early in the period, then eject into the southern High Plains during the afternoon. In response to this feature, lee surface low will deepen over southeast CO before ejecting into southwest KS during the evening. As should be expected, LLJ will increase markedly across the southern/central Plains, which will encourage boundary-layer moisture to advance north across OK into KS. Early this morning, leading edge of 50F surface dewpoints are located over southern OK. This air mass may spread as far north as I-70 by 25/00z, with upper 40s dewpoints likely being drawn toward the CO border, just north of the surface low. Strong boundary-layer heating will be noted across the High Plains of west TX into extreme southwest KS. As a result, convective temperatures will likely be breached by 20z within the exit region of a midlevel jet, where 500mb temperatures are forecast to cool below -20C. Very steep lapse rates and cold profiles will result in ample buoyancy for robust updrafts. Latest thinking is warm advection may generate some early-day elevated convection east of the dryline, but this activity will spread east and the focus for severe will be across the High Plains during peak heating. Scattered supercells are expected to develop immediately ahead of the surface low/dryline within a very dynamically forced environment. While surface dew points may never rise above the mid 50s downstream of this activity, surface-based buoyancy is expected to develop by late evening as far east as the I35 corridor as temperatures aloft cool. Large hail should be common with supercells, and some tornado threat also exists given the strong shear and surface-based nature of this activity. Convection will spread/develop east during the overnight hours as the upper trough progresses downstream. Farther south across TX, convection may initially struggle to develop along the dryline due to warmer midlevel temperatures and some CINH. However, significant midlevel cooling will be noted after 25/00z and profiles should adjust and become favorable for convective development. Latest model guidance, including the HREF, suggest this activity may be more linear in nature, though strongly sheared. Forward-propagating squall line may advance across TX and southern OK during the overnight hours, with an attendant risk for gusty winds, some hail and/or a brief tornado. The coverage of severe may remain a bit too isolated to warrant a SLGT risk, but this will be monitored and adjusted as conditions warrant. ..Darrow/Squitieri.. 03/24/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Sun Mar 24 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL/SOUTHERN PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms should develop this afternoon and persist through Sunday night across parts of the southern/central Plains. Large hail and a few tornadoes are expected to be the main threats, but occasional severe winds may also occur. ...Central/Southern Plains... Strong southern-stream short-wave trough is forecast to shift across northwest Mexico early in the period, then eject into the southern High Plains during the afternoon. In response to this feature, lee surface low will deepen over southeast CO before ejecting into southwest KS during the evening. As should be expected, LLJ will increase markedly across the southern/central Plains, which will encourage boundary-layer moisture to advance north across OK into KS. Early this morning, leading edge of 50F surface dewpoints are located over southern OK. This air mass may spread as far north as I-70 by 25/00z, with upper 40s dewpoints likely being drawn toward the CO border, just north of the surface low. Strong boundary-layer heating will be noted across the High Plains of west TX into extreme southwest KS. As a result, convective temperatures will likely be breached by 20z within the exit region of a midlevel jet, where 500mb temperatures are forecast to cool below -20C. Very steep lapse rates and cold profiles will result in ample buoyancy for robust updrafts. Latest thinking is warm advection may generate some early-day elevated convection east of the dryline, but this activity will spread east and the focus for severe will be across the High Plains during peak heating. Scattered supercells are expected to develop immediately ahead of the surface low/dryline within a very dynamically forced environment. While surface dew points may never rise above the mid 50s downstream of this activity, surface-based buoyancy is expected to develop by late evening as far east as the I35 corridor as temperatures aloft cool. Large hail should be common with supercells, and some tornado threat also exists given the strong shear and surface-based nature of this activity. Convection will spread/develop east during the overnight hours as the upper trough progresses downstream. Farther south across TX, convection may initially struggle to develop along the dryline due to warmer midlevel temperatures and some CINH. However, significant midlevel cooling will be noted after 25/00z and profiles should adjust and become favorable for convective development. Latest model guidance, including the HREF, suggest this activity may be more linear in nature, though strongly sheared. Forward-propagating squall line may advance across TX and southern OK during the overnight hours, with an attendant risk for gusty winds, some hail and/or a brief tornado. The coverage of severe may remain a bit too isolated to warrant a SLGT risk, but this will be monitored and adjusted as conditions warrant. ..Darrow/Squitieri.. 03/24/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1244 AM CDT Sun Mar 24 2024 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE CENTRAL/SOUTHERN PLAINS... ...SUMMARY... Isolated to scattered severe thunderstorms should develop this afternoon and persist through Sunday night across parts of the southern/central Plains. Large hail and a few tornadoes are expected to be the main threats, but occasional severe winds may also occur. ...Central/Southern Plains... Strong southern-stream short-wave trough is forecast to shift across northwest Mexico early in the period, then eject into the southern High Plains during the afternoon. In response to this feature, lee surface low will deepen over southeast CO before ejecting into southwest KS during the evening. As should be expected, LLJ will increase markedly across the southern/central Plains, which will encourage boundary-layer moisture to advance north across OK into KS. Early this morning, leading edge of 50F surface dewpoints are located over southern OK. This air mass may spread as far north as I-70 by 25/00z, with upper 40s dewpoints likely being drawn toward the CO border, just north of the surface low. Strong boundary-layer heating will be noted across the High Plains of west TX into extreme southwest KS. As a result, convective temperatures will likely be breached by 20z within the exit region of a midlevel jet, where 500mb temperatures are forecast to cool below -20C. Very steep lapse rates and cold profiles will result in ample buoyancy for robust updrafts. Latest thinking is warm advection may generate some early-day elevated convection east of the dryline, but this activity will spread east and the focus for severe will be across the High Plains during peak heating. Scattered supercells are expected to develop immediately ahead of the surface low/dryline within a very dynamically forced environment. While surface dew points may never rise above the mid 50s downstream of this activity, surface-based buoyancy is expected to develop by late evening as far east as the I35 corridor as temperatures aloft cool. Large hail should be common with supercells, and some tornado threat also exists given the strong shear and surface-based nature of this activity. Convection will spread/develop east during the overnight hours as the upper trough progresses downstream. Farther south across TX, convection may initially struggle to develop along the dryline due to warmer midlevel temperatures and some CINH. However, significant midlevel cooling will be noted after 25/00z and profiles should adjust and become favorable for convective development. Latest model guidance, including the HREF, suggest this activity may be more linear in nature, though strongly sheared. Forward-propagating squall line may advance across TX and southern OK during the overnight hours, with an attendant risk for gusty winds, some hail and/or a brief tornado. The coverage of severe may remain a bit too isolated to warrant a SLGT risk, but this will be monitored and adjusted as conditions warrant. ..Darrow/Squitieri.. 03/24/2024 Read more

MD 0289 CONCERNING HEAVY SNOW FOR PORTIONS OF CENTRAL VERMONT AND NEW HAMPSHIRE INTO CENTRAL MAINE
Mesoscale Discussion 0289 NWS Storm Prediction Center Norman OK 0610 PM CDT Sat Mar 23 2024 Areas affected...portions of central Vermont and New Hampshire into central Maine Concerning...Heavy snow Valid 232310Z - 240415Z SUMMARY...Heavy snow should continue across northern parts of New England into the evening hours. 1-2 inch/hr snowfall rates and periods of reduced visibility are possible, especially after 00Z (8 PM EDT). DISCUSSION...Heavy snow is ongoing to the north of a strong low-level cyclone that is currently traversing the Atlantic Coastline. Regional dual-polarimetric radar data depicts the transition line between all snow and mixed wintry precipitation to be established from roughly the MA/VT border to central Penobscot County, ME, and the latest high-resolution model guidance suggests that this transition line should remain roughly stationary into the evening hours. 700 mb frontogenesis is increasing along the international border in tandem with increasing low-level WAA, and this should encourage increased snowfall rates as moisture and lift are boosted within the dendritic growth zone. 1-2 inch/hr snowfall rates are possible, especially later this evening (i.e. the 00-05Z time frame). ..Squitieri.. 03/23/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CAR...GYX...BTV...ALY... LAT...LON 42907323 44437176 45367043 46406884 46406806 46226770 45906762 45506784 45006851 44796918 43917096 43387180 42817274 42907323 Read more

MD 0290 CONCERNING FREEZING RAIN FOR PORTIONS OF SOUTHERN MAINE
Mesoscale Discussion 0290 NWS Storm Prediction Center Norman OK 0817 PM CDT Sat Mar 23 2024 Areas affected...Portions of southern Maine Concerning...Freezing rain Valid 240117Z - 240315Z SUMMARY...Freezing rain will remain a concern across portions of southern Maine for at least the next few hours. Occasional instances of sleet or snow are also possible. DISCUSSION...KGYX and KCBW dual polarimetric radar data continues to show a stationary transition zone between rain and a wintry mix, roughly oriented from York to northern Washington County Maine. This boundary should only slowly progress eastward over the next few hours as the low-level cyclone continues to parallel the boundary orientation and traverse the Atlantic Coastline. While snow (occasionally heavy) will continue to the north of the transition zone, freezing rain and occasional instances of a rain/snow/sleet mix should persist nearer to the Maine coastline. Here, surface temperatures hover around the freezing mark, but temperatures above the surface have warmed above freezing given strong WAA. 0.05 inch/3 hour ice accretion rates are most likely 20+ nautical miles inland, where surface temperatures remain around 31-32 F, which is in agreement with some of the latest high-resolution model guidance. ..Squitieri.. 03/24/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CAR...GYX... LAT...LON 43627100 43777109 43787092 43927067 44137024 44426959 44726887 45016814 45016752 44806749 44206827 43876908 43626980 43417034 43317063 43367085 43627100 Read more

MD 0288 CONCERNING WINTER MIXED PRECIPITATION FOR PORTIONS OF SOUTHERN MAINE AND NEW HAMPSHIRE
Mesoscale Discussion 0288 NWS Storm Prediction Center Norman OK 0457 PM CDT Sat Mar 23 2024 Areas affected...portions of southern Maine and New Hampshire Concerning...Winter mixed precipitation Valid 232157Z - 240100Z SUMMARY...Mixed precipitation should continue across portions of northern New England over the next few hours. Freezing rain is also possible, with ice accretion rates exceeding 0.05 inches/3 hrs in some spots. DISCUSSION...A surface low, located just off the coast of NJ, is poised to traverse the coastline through the evening as a mid-level trough overspreads the region. Strong surface-700 mb warm-air/moisture advection is underway along the New England coast, promoting widespread wintry precipitation. Snow should remain the predominant precipitation type across northern parts of ME and NH. However, temperatures are rising above the freezing mark in the lowest couple hundred mb, allowing for mixed wintry precipitation to occur. Along and just north of surface freezing line, ice accumulations have been reported, and ice accretion rates of up to 0.05 inches/3 hrs, as well as sleet, are possible where rainfall is heaviest. ..Squitieri.. 03/23/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GYX... LAT...LON 43177049 42887137 42987202 43627207 43717125 44276974 44196909 43776958 43177049 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0735 PM CDT Sat Mar 23 2024 Valid 240100Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected tonight. ...01z Update... Bimodal eastern US trough will continue progressing east overnight. Large-scale forcing for convection has shifted offshore and nocturnal cooling will lead to weakening updrafts along the northern FL Atlantic Coast over the next hour or so. Across the western US, isolated thunderstorms continue across interior CA into UT ahead of a pronounced upper trough advancing inland. Later tonight, strong 500mb speed max will translate across the northern Baja Peninsula/northern Gulf of CA into northern Mexico. Cooling profiles aloft and steepening lapse rates will contribute to buoyancy necessary for scattered thunderstorm development along/ahead of the primary synoptic front. Main concentration of lightning should be across AZ, starting later this evening into the early-morning hours. ..Darrow.. 03/24/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0735 PM CDT Sat Mar 23 2024 Valid 240100Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected tonight. ...01z Update... Bimodal eastern US trough will continue progressing east overnight. Large-scale forcing for convection has shifted offshore and nocturnal cooling will lead to weakening updrafts along the northern FL Atlantic Coast over the next hour or so. Across the western US, isolated thunderstorms continue across interior CA into UT ahead of a pronounced upper trough advancing inland. Later tonight, strong 500mb speed max will translate across the northern Baja Peninsula/northern Gulf of CA into northern Mexico. Cooling profiles aloft and steepening lapse rates will contribute to buoyancy necessary for scattered thunderstorm development along/ahead of the primary synoptic front. Main concentration of lightning should be across AZ, starting later this evening into the early-morning hours. ..Darrow.. 03/24/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0735 PM CDT Sat Mar 23 2024 Valid 240100Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected tonight. ...01z Update... Bimodal eastern US trough will continue progressing east overnight. Large-scale forcing for convection has shifted offshore and nocturnal cooling will lead to weakening updrafts along the northern FL Atlantic Coast over the next hour or so. Across the western US, isolated thunderstorms continue across interior CA into UT ahead of a pronounced upper trough advancing inland. Later tonight, strong 500mb speed max will translate across the northern Baja Peninsula/northern Gulf of CA into northern Mexico. Cooling profiles aloft and steepening lapse rates will contribute to buoyancy necessary for scattered thunderstorm development along/ahead of the primary synoptic front. Main concentration of lightning should be across AZ, starting later this evening into the early-morning hours. ..Darrow.. 03/24/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0735 PM CDT Sat Mar 23 2024 Valid 240100Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected tonight. ...01z Update... Bimodal eastern US trough will continue progressing east overnight. Large-scale forcing for convection has shifted offshore and nocturnal cooling will lead to weakening updrafts along the northern FL Atlantic Coast over the next hour or so. Across the western US, isolated thunderstorms continue across interior CA into UT ahead of a pronounced upper trough advancing inland. Later tonight, strong 500mb speed max will translate across the northern Baja Peninsula/northern Gulf of CA into northern Mexico. Cooling profiles aloft and steepening lapse rates will contribute to buoyancy necessary for scattered thunderstorm development along/ahead of the primary synoptic front. Main concentration of lightning should be across AZ, starting later this evening into the early-morning hours. ..Darrow.. 03/24/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0735 PM CDT Sat Mar 23 2024 Valid 240100Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected tonight. ...01z Update... Bimodal eastern US trough will continue progressing east overnight. Large-scale forcing for convection has shifted offshore and nocturnal cooling will lead to weakening updrafts along the northern FL Atlantic Coast over the next hour or so. Across the western US, isolated thunderstorms continue across interior CA into UT ahead of a pronounced upper trough advancing inland. Later tonight, strong 500mb speed max will translate across the northern Baja Peninsula/northern Gulf of CA into northern Mexico. Cooling profiles aloft and steepening lapse rates will contribute to buoyancy necessary for scattered thunderstorm development along/ahead of the primary synoptic front. Main concentration of lightning should be across AZ, starting later this evening into the early-morning hours. ..Darrow.. 03/24/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0735 PM CDT Sat Mar 23 2024 Valid 240100Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected tonight. ...01z Update... Bimodal eastern US trough will continue progressing east overnight. Large-scale forcing for convection has shifted offshore and nocturnal cooling will lead to weakening updrafts along the northern FL Atlantic Coast over the next hour or so. Across the western US, isolated thunderstorms continue across interior CA into UT ahead of a pronounced upper trough advancing inland. Later tonight, strong 500mb speed max will translate across the northern Baja Peninsula/northern Gulf of CA into northern Mexico. Cooling profiles aloft and steepening lapse rates will contribute to buoyancy necessary for scattered thunderstorm development along/ahead of the primary synoptic front. Main concentration of lightning should be across AZ, starting later this evening into the early-morning hours. ..Darrow.. 03/24/2024 Read more