Severe Storms

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1147 AM CDT Tue Sep 24 2024 Valid 241700Z - 251200Z ...NO CRITICAL AREAS... No changes. See previous discussion below. ..Bentley.. 09/24/2024 .PREV DISCUSSION... /ISSUED 0153 AM CDT Tue Sep 24 2024/ ...Synopsis... Fire weather concerns will remain low today across the CONUS. A ridge will build in across the western US, with dry and warming conditions amid generally light winds. Longwave troughing will deepen across the Plains, with some post-frontal northwesterly breezes across the High Plains. Overall, cool conditions will keep relative humidity values high and there is potential for wetting rainfall. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1145 AM CDT Tue Sep 24 2024 Valid 241630Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF TN/KY/OH/WV AND CENTRAL OK... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this afternoon across portions of the Ohio and Tennessee Valleys into the central/southern Appalachians. Severe storms will also be possible across portions of Oklahoma. ...Ohio and Tennessee Valleys to southern Appalachians... Have spatially adjusted/expanded the Slight Risk based on observational trends and somewhat stronger destabilization across areas such as northern/middle Tennessee. Water-vapor imagery shows a mid-level vorticity maximum moving across the middle Mississippi Valley and into the Ohio Valley. A belt of moderate to strong southwesterly 500-mb flow (25-50 kt) will overspread Kentucky and the surrounding states. A surface low will migrate east-northeast into southern Lower Michigan by early evening, where isolated severe storms are possible, with a frontal zone extending south-southwest from this low into the Mid South. In the wake of early morning convection, modest cloud breaks/destabilization is forecast with upwards of 750-2000 J/kg MLCAPE from the southern Great Lakes into the southern Appalachians, with the strongest destabilization expected across Tennessee into southern Kentucky and possibly the western Carolinas pending the timing/abatement of lingering cloud cover. Regionally, ample deep-layer speed shear will aid in storm organization into organized multicells and probably several supercells. Damaging winds will be the most common hazard, but isolated large hail will be possible, and some tornado risk may exist as well. ...Oklahoma/North Texas... Have upgraded portions of central Oklahoma for what is expected to be a semi-focused regional corridor of large hail potential late this afternoon and early evening. The region will be influenced by the immediate backside of a southeastward-moving upper-level trough centered over the Lower Missouri Valley. A considerably strengthening cyclonically curved belt of westerlies aloft will influence Oklahoma, overspreading a relatively moist air mass, with lower to some middle 60s F surface dewpoints likely to persist through the diurnal heating/mixing cycle. Near a deepening surface low and nearby triple point/warm front, at least isolated storms are expected to develop as early as mid-afternoon (3-4pm), becoming more probable with a greater coverage through sunset. Overall buoyancy will not be robust, with MLCAPE generally not expected to exceed 1000 J/kg later this afternoon. However, this buoyancy, along with steep lapse rates and robustly vertically veering wind profiles, accentuated by 35-45 kt northwesterly mid/upper-level flow, should support initial supercells capable of large hail (potentially golfball size), along with some potential for damaging wind gusts. These storms will persist generally southeastward through the evening into southern/southeast Oklahoma, and probably north Texas overnight. Overall intensity will tend to wane nocturnally after sunset, but some severe hail/wind potential will probably linger, particularly on the west/southwest flank of any evolving clusters of storms, which will be increasingly elevated to the east of the warm front. ..Guyer/Lyons.. 09/24/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1145 AM CDT Tue Sep 24 2024 Valid 241630Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF TN/KY/OH/WV AND CENTRAL OK... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this afternoon across portions of the Ohio and Tennessee Valleys into the central/southern Appalachians. Severe storms will also be possible across portions of Oklahoma. ...Ohio and Tennessee Valleys to southern Appalachians... Have spatially adjusted/expanded the Slight Risk based on observational trends and somewhat stronger destabilization across areas such as northern/middle Tennessee. Water-vapor imagery shows a mid-level vorticity maximum moving across the middle Mississippi Valley and into the Ohio Valley. A belt of moderate to strong southwesterly 500-mb flow (25-50 kt) will overspread Kentucky and the surrounding states. A surface low will migrate east-northeast into southern Lower Michigan by early evening, where isolated severe storms are possible, with a frontal zone extending south-southwest from this low into the Mid South. In the wake of early morning convection, modest cloud breaks/destabilization is forecast with upwards of 750-2000 J/kg MLCAPE from the southern Great Lakes into the southern Appalachians, with the strongest destabilization expected across Tennessee into southern Kentucky and possibly the western Carolinas pending the timing/abatement of lingering cloud cover. Regionally, ample deep-layer speed shear will aid in storm organization into organized multicells and probably several supercells. Damaging winds will be the most common hazard, but isolated large hail will be possible, and some tornado risk may exist as well. ...Oklahoma/North Texas... Have upgraded portions of central Oklahoma for what is expected to be a semi-focused regional corridor of large hail potential late this afternoon and early evening. The region will be influenced by the immediate backside of a southeastward-moving upper-level trough centered over the Lower Missouri Valley. A considerably strengthening cyclonically curved belt of westerlies aloft will influence Oklahoma, overspreading a relatively moist air mass, with lower to some middle 60s F surface dewpoints likely to persist through the diurnal heating/mixing cycle. Near a deepening surface low and nearby triple point/warm front, at least isolated storms are expected to develop as early as mid-afternoon (3-4pm), becoming more probable with a greater coverage through sunset. Overall buoyancy will not be robust, with MLCAPE generally not expected to exceed 1000 J/kg later this afternoon. However, this buoyancy, along with steep lapse rates and robustly vertically veering wind profiles, accentuated by 35-45 kt northwesterly mid/upper-level flow, should support initial supercells capable of large hail (potentially golfball size), along with some potential for damaging wind gusts. These storms will persist generally southeastward through the evening into southern/southeast Oklahoma, and probably north Texas overnight. Overall intensity will tend to wane nocturnally after sunset, but some severe hail/wind potential will probably linger, particularly on the west/southwest flank of any evolving clusters of storms, which will be increasingly elevated to the east of the warm front. ..Guyer/Lyons.. 09/24/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1145 AM CDT Tue Sep 24 2024 Valid 241630Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF TN/KY/OH/WV AND CENTRAL OK... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this afternoon across portions of the Ohio and Tennessee Valleys into the central/southern Appalachians. Severe storms will also be possible across portions of Oklahoma. ...Ohio and Tennessee Valleys to southern Appalachians... Have spatially adjusted/expanded the Slight Risk based on observational trends and somewhat stronger destabilization across areas such as northern/middle Tennessee. Water-vapor imagery shows a mid-level vorticity maximum moving across the middle Mississippi Valley and into the Ohio Valley. A belt of moderate to strong southwesterly 500-mb flow (25-50 kt) will overspread Kentucky and the surrounding states. A surface low will migrate east-northeast into southern Lower Michigan by early evening, where isolated severe storms are possible, with a frontal zone extending south-southwest from this low into the Mid South. In the wake of early morning convection, modest cloud breaks/destabilization is forecast with upwards of 750-2000 J/kg MLCAPE from the southern Great Lakes into the southern Appalachians, with the strongest destabilization expected across Tennessee into southern Kentucky and possibly the western Carolinas pending the timing/abatement of lingering cloud cover. Regionally, ample deep-layer speed shear will aid in storm organization into organized multicells and probably several supercells. Damaging winds will be the most common hazard, but isolated large hail will be possible, and some tornado risk may exist as well. ...Oklahoma/North Texas... Have upgraded portions of central Oklahoma for what is expected to be a semi-focused regional corridor of large hail potential late this afternoon and early evening. The region will be influenced by the immediate backside of a southeastward-moving upper-level trough centered over the Lower Missouri Valley. A considerably strengthening cyclonically curved belt of westerlies aloft will influence Oklahoma, overspreading a relatively moist air mass, with lower to some middle 60s F surface dewpoints likely to persist through the diurnal heating/mixing cycle. Near a deepening surface low and nearby triple point/warm front, at least isolated storms are expected to develop as early as mid-afternoon (3-4pm), becoming more probable with a greater coverage through sunset. Overall buoyancy will not be robust, with MLCAPE generally not expected to exceed 1000 J/kg later this afternoon. However, this buoyancy, along with steep lapse rates and robustly vertically veering wind profiles, accentuated by 35-45 kt northwesterly mid/upper-level flow, should support initial supercells capable of large hail (potentially golfball size), along with some potential for damaging wind gusts. These storms will persist generally southeastward through the evening into southern/southeast Oklahoma, and probably north Texas overnight. Overall intensity will tend to wane nocturnally after sunset, but some severe hail/wind potential will probably linger, particularly on the west/southwest flank of any evolving clusters of storms, which will be increasingly elevated to the east of the warm front. ..Guyer/Lyons.. 09/24/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1145 AM CDT Tue Sep 24 2024 Valid 241630Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF TN/KY/OH/WV AND CENTRAL OK... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this afternoon across portions of the Ohio and Tennessee Valleys into the central/southern Appalachians. Severe storms will also be possible across portions of Oklahoma. ...Ohio and Tennessee Valleys to southern Appalachians... Have spatially adjusted/expanded the Slight Risk based on observational trends and somewhat stronger destabilization across areas such as northern/middle Tennessee. Water-vapor imagery shows a mid-level vorticity maximum moving across the middle Mississippi Valley and into the Ohio Valley. A belt of moderate to strong southwesterly 500-mb flow (25-50 kt) will overspread Kentucky and the surrounding states. A surface low will migrate east-northeast into southern Lower Michigan by early evening, where isolated severe storms are possible, with a frontal zone extending south-southwest from this low into the Mid South. In the wake of early morning convection, modest cloud breaks/destabilization is forecast with upwards of 750-2000 J/kg MLCAPE from the southern Great Lakes into the southern Appalachians, with the strongest destabilization expected across Tennessee into southern Kentucky and possibly the western Carolinas pending the timing/abatement of lingering cloud cover. Regionally, ample deep-layer speed shear will aid in storm organization into organized multicells and probably several supercells. Damaging winds will be the most common hazard, but isolated large hail will be possible, and some tornado risk may exist as well. ...Oklahoma/North Texas... Have upgraded portions of central Oklahoma for what is expected to be a semi-focused regional corridor of large hail potential late this afternoon and early evening. The region will be influenced by the immediate backside of a southeastward-moving upper-level trough centered over the Lower Missouri Valley. A considerably strengthening cyclonically curved belt of westerlies aloft will influence Oklahoma, overspreading a relatively moist air mass, with lower to some middle 60s F surface dewpoints likely to persist through the diurnal heating/mixing cycle. Near a deepening surface low and nearby triple point/warm front, at least isolated storms are expected to develop as early as mid-afternoon (3-4pm), becoming more probable with a greater coverage through sunset. Overall buoyancy will not be robust, with MLCAPE generally not expected to exceed 1000 J/kg later this afternoon. However, this buoyancy, along with steep lapse rates and robustly vertically veering wind profiles, accentuated by 35-45 kt northwesterly mid/upper-level flow, should support initial supercells capable of large hail (potentially golfball size), along with some potential for damaging wind gusts. These storms will persist generally southeastward through the evening into southern/southeast Oklahoma, and probably north Texas overnight. Overall intensity will tend to wane nocturnally after sunset, but some severe hail/wind potential will probably linger, particularly on the west/southwest flank of any evolving clusters of storms, which will be increasingly elevated to the east of the warm front. ..Guyer/Lyons.. 09/24/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1145 AM CDT Tue Sep 24 2024 Valid 241630Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF TN/KY/OH/WV AND CENTRAL OK... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this afternoon across portions of the Ohio and Tennessee Valleys into the central/southern Appalachians. Severe storms will also be possible across portions of Oklahoma. ...Ohio and Tennessee Valleys to southern Appalachians... Have spatially adjusted/expanded the Slight Risk based on observational trends and somewhat stronger destabilization across areas such as northern/middle Tennessee. Water-vapor imagery shows a mid-level vorticity maximum moving across the middle Mississippi Valley and into the Ohio Valley. A belt of moderate to strong southwesterly 500-mb flow (25-50 kt) will overspread Kentucky and the surrounding states. A surface low will migrate east-northeast into southern Lower Michigan by early evening, where isolated severe storms are possible, with a frontal zone extending south-southwest from this low into the Mid South. In the wake of early morning convection, modest cloud breaks/destabilization is forecast with upwards of 750-2000 J/kg MLCAPE from the southern Great Lakes into the southern Appalachians, with the strongest destabilization expected across Tennessee into southern Kentucky and possibly the western Carolinas pending the timing/abatement of lingering cloud cover. Regionally, ample deep-layer speed shear will aid in storm organization into organized multicells and probably several supercells. Damaging winds will be the most common hazard, but isolated large hail will be possible, and some tornado risk may exist as well. ...Oklahoma/North Texas... Have upgraded portions of central Oklahoma for what is expected to be a semi-focused regional corridor of large hail potential late this afternoon and early evening. The region will be influenced by the immediate backside of a southeastward-moving upper-level trough centered over the Lower Missouri Valley. A considerably strengthening cyclonically curved belt of westerlies aloft will influence Oklahoma, overspreading a relatively moist air mass, with lower to some middle 60s F surface dewpoints likely to persist through the diurnal heating/mixing cycle. Near a deepening surface low and nearby triple point/warm front, at least isolated storms are expected to develop as early as mid-afternoon (3-4pm), becoming more probable with a greater coverage through sunset. Overall buoyancy will not be robust, with MLCAPE generally not expected to exceed 1000 J/kg later this afternoon. However, this buoyancy, along with steep lapse rates and robustly vertically veering wind profiles, accentuated by 35-45 kt northwesterly mid/upper-level flow, should support initial supercells capable of large hail (potentially golfball size), along with some potential for damaging wind gusts. These storms will persist generally southeastward through the evening into southern/southeast Oklahoma, and probably north Texas overnight. Overall intensity will tend to wane nocturnally after sunset, but some severe hail/wind potential will probably linger, particularly on the west/southwest flank of any evolving clusters of storms, which will be increasingly elevated to the east of the warm front. ..Guyer/Lyons.. 09/24/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1145 AM CDT Tue Sep 24 2024 Valid 241630Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF TN/KY/OH/WV AND CENTRAL OK... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this afternoon across portions of the Ohio and Tennessee Valleys into the central/southern Appalachians. Severe storms will also be possible across portions of Oklahoma. ...Ohio and Tennessee Valleys to southern Appalachians... Have spatially adjusted/expanded the Slight Risk based on observational trends and somewhat stronger destabilization across areas such as northern/middle Tennessee. Water-vapor imagery shows a mid-level vorticity maximum moving across the middle Mississippi Valley and into the Ohio Valley. A belt of moderate to strong southwesterly 500-mb flow (25-50 kt) will overspread Kentucky and the surrounding states. A surface low will migrate east-northeast into southern Lower Michigan by early evening, where isolated severe storms are possible, with a frontal zone extending south-southwest from this low into the Mid South. In the wake of early morning convection, modest cloud breaks/destabilization is forecast with upwards of 750-2000 J/kg MLCAPE from the southern Great Lakes into the southern Appalachians, with the strongest destabilization expected across Tennessee into southern Kentucky and possibly the western Carolinas pending the timing/abatement of lingering cloud cover. Regionally, ample deep-layer speed shear will aid in storm organization into organized multicells and probably several supercells. Damaging winds will be the most common hazard, but isolated large hail will be possible, and some tornado risk may exist as well. ...Oklahoma/North Texas... Have upgraded portions of central Oklahoma for what is expected to be a semi-focused regional corridor of large hail potential late this afternoon and early evening. The region will be influenced by the immediate backside of a southeastward-moving upper-level trough centered over the Lower Missouri Valley. A considerably strengthening cyclonically curved belt of westerlies aloft will influence Oklahoma, overspreading a relatively moist air mass, with lower to some middle 60s F surface dewpoints likely to persist through the diurnal heating/mixing cycle. Near a deepening surface low and nearby triple point/warm front, at least isolated storms are expected to develop as early as mid-afternoon (3-4pm), becoming more probable with a greater coverage through sunset. Overall buoyancy will not be robust, with MLCAPE generally not expected to exceed 1000 J/kg later this afternoon. However, this buoyancy, along with steep lapse rates and robustly vertically veering wind profiles, accentuated by 35-45 kt northwesterly mid/upper-level flow, should support initial supercells capable of large hail (potentially golfball size), along with some potential for damaging wind gusts. These storms will persist generally southeastward through the evening into southern/southeast Oklahoma, and probably north Texas overnight. Overall intensity will tend to wane nocturnally after sunset, but some severe hail/wind potential will probably linger, particularly on the west/southwest flank of any evolving clusters of storms, which will be increasingly elevated to the east of the warm front. ..Guyer/Lyons.. 09/24/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1145 AM CDT Tue Sep 24 2024 Valid 241630Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF TN/KY/OH/WV AND CENTRAL OK... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this afternoon across portions of the Ohio and Tennessee Valleys into the central/southern Appalachians. Severe storms will also be possible across portions of Oklahoma. ...Ohio and Tennessee Valleys to southern Appalachians... Have spatially adjusted/expanded the Slight Risk based on observational trends and somewhat stronger destabilization across areas such as northern/middle Tennessee. Water-vapor imagery shows a mid-level vorticity maximum moving across the middle Mississippi Valley and into the Ohio Valley. A belt of moderate to strong southwesterly 500-mb flow (25-50 kt) will overspread Kentucky and the surrounding states. A surface low will migrate east-northeast into southern Lower Michigan by early evening, where isolated severe storms are possible, with a frontal zone extending south-southwest from this low into the Mid South. In the wake of early morning convection, modest cloud breaks/destabilization is forecast with upwards of 750-2000 J/kg MLCAPE from the southern Great Lakes into the southern Appalachians, with the strongest destabilization expected across Tennessee into southern Kentucky and possibly the western Carolinas pending the timing/abatement of lingering cloud cover. Regionally, ample deep-layer speed shear will aid in storm organization into organized multicells and probably several supercells. Damaging winds will be the most common hazard, but isolated large hail will be possible, and some tornado risk may exist as well. ...Oklahoma/North Texas... Have upgraded portions of central Oklahoma for what is expected to be a semi-focused regional corridor of large hail potential late this afternoon and early evening. The region will be influenced by the immediate backside of a southeastward-moving upper-level trough centered over the Lower Missouri Valley. A considerably strengthening cyclonically curved belt of westerlies aloft will influence Oklahoma, overspreading a relatively moist air mass, with lower to some middle 60s F surface dewpoints likely to persist through the diurnal heating/mixing cycle. Near a deepening surface low and nearby triple point/warm front, at least isolated storms are expected to develop as early as mid-afternoon (3-4pm), becoming more probable with a greater coverage through sunset. Overall buoyancy will not be robust, with MLCAPE generally not expected to exceed 1000 J/kg later this afternoon. However, this buoyancy, along with steep lapse rates and robustly vertically veering wind profiles, accentuated by 35-45 kt northwesterly mid/upper-level flow, should support initial supercells capable of large hail (potentially golfball size), along with some potential for damaging wind gusts. These storms will persist generally southeastward through the evening into southern/southeast Oklahoma, and probably north Texas overnight. Overall intensity will tend to wane nocturnally after sunset, but some severe hail/wind potential will probably linger, particularly on the west/southwest flank of any evolving clusters of storms, which will be increasingly elevated to the east of the warm front. ..Guyer/Lyons.. 09/24/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1145 AM CDT Tue Sep 24 2024 Valid 241630Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF TN/KY/OH/WV AND CENTRAL OK... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this afternoon across portions of the Ohio and Tennessee Valleys into the central/southern Appalachians. Severe storms will also be possible across portions of Oklahoma. ...Ohio and Tennessee Valleys to southern Appalachians... Have spatially adjusted/expanded the Slight Risk based on observational trends and somewhat stronger destabilization across areas such as northern/middle Tennessee. Water-vapor imagery shows a mid-level vorticity maximum moving across the middle Mississippi Valley and into the Ohio Valley. A belt of moderate to strong southwesterly 500-mb flow (25-50 kt) will overspread Kentucky and the surrounding states. A surface low will migrate east-northeast into southern Lower Michigan by early evening, where isolated severe storms are possible, with a frontal zone extending south-southwest from this low into the Mid South. In the wake of early morning convection, modest cloud breaks/destabilization is forecast with upwards of 750-2000 J/kg MLCAPE from the southern Great Lakes into the southern Appalachians, with the strongest destabilization expected across Tennessee into southern Kentucky and possibly the western Carolinas pending the timing/abatement of lingering cloud cover. Regionally, ample deep-layer speed shear will aid in storm organization into organized multicells and probably several supercells. Damaging winds will be the most common hazard, but isolated large hail will be possible, and some tornado risk may exist as well. ...Oklahoma/North Texas... Have upgraded portions of central Oklahoma for what is expected to be a semi-focused regional corridor of large hail potential late this afternoon and early evening. The region will be influenced by the immediate backside of a southeastward-moving upper-level trough centered over the Lower Missouri Valley. A considerably strengthening cyclonically curved belt of westerlies aloft will influence Oklahoma, overspreading a relatively moist air mass, with lower to some middle 60s F surface dewpoints likely to persist through the diurnal heating/mixing cycle. Near a deepening surface low and nearby triple point/warm front, at least isolated storms are expected to develop as early as mid-afternoon (3-4pm), becoming more probable with a greater coverage through sunset. Overall buoyancy will not be robust, with MLCAPE generally not expected to exceed 1000 J/kg later this afternoon. However, this buoyancy, along with steep lapse rates and robustly vertically veering wind profiles, accentuated by 35-45 kt northwesterly mid/upper-level flow, should support initial supercells capable of large hail (potentially golfball size), along with some potential for damaging wind gusts. These storms will persist generally southeastward through the evening into southern/southeast Oklahoma, and probably north Texas overnight. Overall intensity will tend to wane nocturnally after sunset, but some severe hail/wind potential will probably linger, particularly on the west/southwest flank of any evolving clusters of storms, which will be increasingly elevated to the east of the warm front. ..Guyer/Lyons.. 09/24/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1145 AM CDT Tue Sep 24 2024 Valid 241630Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF TN/KY/OH/WV AND CENTRAL OK... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this afternoon across portions of the Ohio and Tennessee Valleys into the central/southern Appalachians. Severe storms will also be possible across portions of Oklahoma. ...Ohio and Tennessee Valleys to southern Appalachians... Have spatially adjusted/expanded the Slight Risk based on observational trends and somewhat stronger destabilization across areas such as northern/middle Tennessee. Water-vapor imagery shows a mid-level vorticity maximum moving across the middle Mississippi Valley and into the Ohio Valley. A belt of moderate to strong southwesterly 500-mb flow (25-50 kt) will overspread Kentucky and the surrounding states. A surface low will migrate east-northeast into southern Lower Michigan by early evening, where isolated severe storms are possible, with a frontal zone extending south-southwest from this low into the Mid South. In the wake of early morning convection, modest cloud breaks/destabilization is forecast with upwards of 750-2000 J/kg MLCAPE from the southern Great Lakes into the southern Appalachians, with the strongest destabilization expected across Tennessee into southern Kentucky and possibly the western Carolinas pending the timing/abatement of lingering cloud cover. Regionally, ample deep-layer speed shear will aid in storm organization into organized multicells and probably several supercells. Damaging winds will be the most common hazard, but isolated large hail will be possible, and some tornado risk may exist as well. ...Oklahoma/North Texas... Have upgraded portions of central Oklahoma for what is expected to be a semi-focused regional corridor of large hail potential late this afternoon and early evening. The region will be influenced by the immediate backside of a southeastward-moving upper-level trough centered over the Lower Missouri Valley. A considerably strengthening cyclonically curved belt of westerlies aloft will influence Oklahoma, overspreading a relatively moist air mass, with lower to some middle 60s F surface dewpoints likely to persist through the diurnal heating/mixing cycle. Near a deepening surface low and nearby triple point/warm front, at least isolated storms are expected to develop as early as mid-afternoon (3-4pm), becoming more probable with a greater coverage through sunset. Overall buoyancy will not be robust, with MLCAPE generally not expected to exceed 1000 J/kg later this afternoon. However, this buoyancy, along with steep lapse rates and robustly vertically veering wind profiles, accentuated by 35-45 kt northwesterly mid/upper-level flow, should support initial supercells capable of large hail (potentially golfball size), along with some potential for damaging wind gusts. These storms will persist generally southeastward through the evening into southern/southeast Oklahoma, and probably north Texas overnight. Overall intensity will tend to wane nocturnally after sunset, but some severe hail/wind potential will probably linger, particularly on the west/southwest flank of any evolving clusters of storms, which will be increasingly elevated to the east of the warm front. ..Guyer/Lyons.. 09/24/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1145 AM CDT Tue Sep 24 2024 Valid 241630Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF TN/KY/OH/WV AND CENTRAL OK... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this afternoon across portions of the Ohio and Tennessee Valleys into the central/southern Appalachians. Severe storms will also be possible across portions of Oklahoma. ...Ohio and Tennessee Valleys to southern Appalachians... Have spatially adjusted/expanded the Slight Risk based on observational trends and somewhat stronger destabilization across areas such as northern/middle Tennessee. Water-vapor imagery shows a mid-level vorticity maximum moving across the middle Mississippi Valley and into the Ohio Valley. A belt of moderate to strong southwesterly 500-mb flow (25-50 kt) will overspread Kentucky and the surrounding states. A surface low will migrate east-northeast into southern Lower Michigan by early evening, where isolated severe storms are possible, with a frontal zone extending south-southwest from this low into the Mid South. In the wake of early morning convection, modest cloud breaks/destabilization is forecast with upwards of 750-2000 J/kg MLCAPE from the southern Great Lakes into the southern Appalachians, with the strongest destabilization expected across Tennessee into southern Kentucky and possibly the western Carolinas pending the timing/abatement of lingering cloud cover. Regionally, ample deep-layer speed shear will aid in storm organization into organized multicells and probably several supercells. Damaging winds will be the most common hazard, but isolated large hail will be possible, and some tornado risk may exist as well. ...Oklahoma/North Texas... Have upgraded portions of central Oklahoma for what is expected to be a semi-focused regional corridor of large hail potential late this afternoon and early evening. The region will be influenced by the immediate backside of a southeastward-moving upper-level trough centered over the Lower Missouri Valley. A considerably strengthening cyclonically curved belt of westerlies aloft will influence Oklahoma, overspreading a relatively moist air mass, with lower to some middle 60s F surface dewpoints likely to persist through the diurnal heating/mixing cycle. Near a deepening surface low and nearby triple point/warm front, at least isolated storms are expected to develop as early as mid-afternoon (3-4pm), becoming more probable with a greater coverage through sunset. Overall buoyancy will not be robust, with MLCAPE generally not expected to exceed 1000 J/kg later this afternoon. However, this buoyancy, along with steep lapse rates and robustly vertically veering wind profiles, accentuated by 35-45 kt northwesterly mid/upper-level flow, should support initial supercells capable of large hail (potentially golfball size), along with some potential for damaging wind gusts. These storms will persist generally southeastward through the evening into southern/southeast Oklahoma, and probably north Texas overnight. Overall intensity will tend to wane nocturnally after sunset, but some severe hail/wind potential will probably linger, particularly on the west/southwest flank of any evolving clusters of storms, which will be increasingly elevated to the east of the warm front. ..Guyer/Lyons.. 09/24/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1145 AM CDT Tue Sep 24 2024 Valid 241630Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF TN/KY/OH/WV AND CENTRAL OK... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this afternoon across portions of the Ohio and Tennessee Valleys into the central/southern Appalachians. Severe storms will also be possible across portions of Oklahoma. ...Ohio and Tennessee Valleys to southern Appalachians... Have spatially adjusted/expanded the Slight Risk based on observational trends and somewhat stronger destabilization across areas such as northern/middle Tennessee. Water-vapor imagery shows a mid-level vorticity maximum moving across the middle Mississippi Valley and into the Ohio Valley. A belt of moderate to strong southwesterly 500-mb flow (25-50 kt) will overspread Kentucky and the surrounding states. A surface low will migrate east-northeast into southern Lower Michigan by early evening, where isolated severe storms are possible, with a frontal zone extending south-southwest from this low into the Mid South. In the wake of early morning convection, modest cloud breaks/destabilization is forecast with upwards of 750-2000 J/kg MLCAPE from the southern Great Lakes into the southern Appalachians, with the strongest destabilization expected across Tennessee into southern Kentucky and possibly the western Carolinas pending the timing/abatement of lingering cloud cover. Regionally, ample deep-layer speed shear will aid in storm organization into organized multicells and probably several supercells. Damaging winds will be the most common hazard, but isolated large hail will be possible, and some tornado risk may exist as well. ...Oklahoma/North Texas... Have upgraded portions of central Oklahoma for what is expected to be a semi-focused regional corridor of large hail potential late this afternoon and early evening. The region will be influenced by the immediate backside of a southeastward-moving upper-level trough centered over the Lower Missouri Valley. A considerably strengthening cyclonically curved belt of westerlies aloft will influence Oklahoma, overspreading a relatively moist air mass, with lower to some middle 60s F surface dewpoints likely to persist through the diurnal heating/mixing cycle. Near a deepening surface low and nearby triple point/warm front, at least isolated storms are expected to develop as early as mid-afternoon (3-4pm), becoming more probable with a greater coverage through sunset. Overall buoyancy will not be robust, with MLCAPE generally not expected to exceed 1000 J/kg later this afternoon. However, this buoyancy, along with steep lapse rates and robustly vertically veering wind profiles, accentuated by 35-45 kt northwesterly mid/upper-level flow, should support initial supercells capable of large hail (potentially golfball size), along with some potential for damaging wind gusts. These storms will persist generally southeastward through the evening into southern/southeast Oklahoma, and probably north Texas overnight. Overall intensity will tend to wane nocturnally after sunset, but some severe hail/wind potential will probably linger, particularly on the west/southwest flank of any evolving clusters of storms, which will be increasingly elevated to the east of the warm front. ..Guyer/Lyons.. 09/24/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1145 AM CDT Tue Sep 24 2024 Valid 241630Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF TN/KY/OH/WV AND CENTRAL OK... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this afternoon across portions of the Ohio and Tennessee Valleys into the central/southern Appalachians. Severe storms will also be possible across portions of Oklahoma. ...Ohio and Tennessee Valleys to southern Appalachians... Have spatially adjusted/expanded the Slight Risk based on observational trends and somewhat stronger destabilization across areas such as northern/middle Tennessee. Water-vapor imagery shows a mid-level vorticity maximum moving across the middle Mississippi Valley and into the Ohio Valley. A belt of moderate to strong southwesterly 500-mb flow (25-50 kt) will overspread Kentucky and the surrounding states. A surface low will migrate east-northeast into southern Lower Michigan by early evening, where isolated severe storms are possible, with a frontal zone extending south-southwest from this low into the Mid South. In the wake of early morning convection, modest cloud breaks/destabilization is forecast with upwards of 750-2000 J/kg MLCAPE from the southern Great Lakes into the southern Appalachians, with the strongest destabilization expected across Tennessee into southern Kentucky and possibly the western Carolinas pending the timing/abatement of lingering cloud cover. Regionally, ample deep-layer speed shear will aid in storm organization into organized multicells and probably several supercells. Damaging winds will be the most common hazard, but isolated large hail will be possible, and some tornado risk may exist as well. ...Oklahoma/North Texas... Have upgraded portions of central Oklahoma for what is expected to be a semi-focused regional corridor of large hail potential late this afternoon and early evening. The region will be influenced by the immediate backside of a southeastward-moving upper-level trough centered over the Lower Missouri Valley. A considerably strengthening cyclonically curved belt of westerlies aloft will influence Oklahoma, overspreading a relatively moist air mass, with lower to some middle 60s F surface dewpoints likely to persist through the diurnal heating/mixing cycle. Near a deepening surface low and nearby triple point/warm front, at least isolated storms are expected to develop as early as mid-afternoon (3-4pm), becoming more probable with a greater coverage through sunset. Overall buoyancy will not be robust, with MLCAPE generally not expected to exceed 1000 J/kg later this afternoon. However, this buoyancy, along with steep lapse rates and robustly vertically veering wind profiles, accentuated by 35-45 kt northwesterly mid/upper-level flow, should support initial supercells capable of large hail (potentially golfball size), along with some potential for damaging wind gusts. These storms will persist generally southeastward through the evening into southern/southeast Oklahoma, and probably north Texas overnight. Overall intensity will tend to wane nocturnally after sunset, but some severe hail/wind potential will probably linger, particularly on the west/southwest flank of any evolving clusters of storms, which will be increasingly elevated to the east of the warm front. ..Guyer/Lyons.. 09/24/2024 Read more

No Mesoscale Discussions are in effect as of Tue Sep 24 12:54:02 UTC 2024.

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 AM CDT Tue Sep 24 2024 Valid 241300Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL KENTUCKY INTO SOUTHERN OHIO AND WEST VIRGINIA... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this afternoon across portions of the Ohio and Tennessee Valleys into the central/southern Appalachians. A few strong/severe storms are also possible across portions of the southern Plains. ...Ohio and Tennessee Valleys to southern Appalachians... Water-vapor imagery this morning shows a mid-level vorticity maximum moving across the middle MS Valley and into the OH Valley. A belt of moderate to strong southwesterly 500-mb flow (25-50 kt) will overspread KY and the surrounding states, with the strongest flow generally within the Slight Risk bounds. Bands of showers/weak thunderstorms are ongoing this morning from middle TN into OH, and in a separate area over eastern IL immediately ahead of the surface low. This low will migrate east-northeast into southern Lower MI by early evening with a frontal zone extending south-southwest into the Mid South. In wake of the early morning convection, some cloud breaks/destabilization is forecast with upwards of 750-2000 J/kg MLCAPE from the southern Great Lakes into the southern Appalachian states. Ample deep-layer speed shear (via mostly southwesterly flow through the troposphere) will aid in storm organization into organized multicells and probably several supercells. Only notable change this outlook update was to include portions of the southern Great Lakes in low-severe probabilities for potential activity near/ahead of the surface low. The primary concern across the general region will likely be damaging winds with the stronger storms. ...OK vicinity... An amplifying large-scale trough over the MS Valley will feature a 60-kt 500mb speed max moving southward into the central Great Plains by early evening on the backside of the upper trough. Left exit region of this feature will encourage large-scale ascent, and a weak surface wave/low should evolve over southwest KS/northwest OK by early afternoon. Strong heating will contribute to 750-1250 J/kg MLCAPE by mid afternoon across OK with flow veering and strengthening with height. Elongated hodographs will support the potential for hail growth with a few of the stronger/sustained updrafts that evolve. An isolated threat for large hail (1 to 1.75 inches in diameter) and/or severe gusts (60-70 mph) will probably peak during the 23z-03z period before storms weaken during the late evening. ..Smith/Broyles.. 09/24/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 AM CDT Tue Sep 24 2024 Valid 241300Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL KENTUCKY INTO SOUTHERN OHIO AND WEST VIRGINIA... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this afternoon across portions of the Ohio and Tennessee Valleys into the central/southern Appalachians. A few strong/severe storms are also possible across portions of the southern Plains. ...Ohio and Tennessee Valleys to southern Appalachians... Water-vapor imagery this morning shows a mid-level vorticity maximum moving across the middle MS Valley and into the OH Valley. A belt of moderate to strong southwesterly 500-mb flow (25-50 kt) will overspread KY and the surrounding states, with the strongest flow generally within the Slight Risk bounds. Bands of showers/weak thunderstorms are ongoing this morning from middle TN into OH, and in a separate area over eastern IL immediately ahead of the surface low. This low will migrate east-northeast into southern Lower MI by early evening with a frontal zone extending south-southwest into the Mid South. In wake of the early morning convection, some cloud breaks/destabilization is forecast with upwards of 750-2000 J/kg MLCAPE from the southern Great Lakes into the southern Appalachian states. Ample deep-layer speed shear (via mostly southwesterly flow through the troposphere) will aid in storm organization into organized multicells and probably several supercells. Only notable change this outlook update was to include portions of the southern Great Lakes in low-severe probabilities for potential activity near/ahead of the surface low. The primary concern across the general region will likely be damaging winds with the stronger storms. ...OK vicinity... An amplifying large-scale trough over the MS Valley will feature a 60-kt 500mb speed max moving southward into the central Great Plains by early evening on the backside of the upper trough. Left exit region of this feature will encourage large-scale ascent, and a weak surface wave/low should evolve over southwest KS/northwest OK by early afternoon. Strong heating will contribute to 750-1250 J/kg MLCAPE by mid afternoon across OK with flow veering and strengthening with height. Elongated hodographs will support the potential for hail growth with a few of the stronger/sustained updrafts that evolve. An isolated threat for large hail (1 to 1.75 inches in diameter) and/or severe gusts (60-70 mph) will probably peak during the 23z-03z period before storms weaken during the late evening. ..Smith/Broyles.. 09/24/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 AM CDT Tue Sep 24 2024 Valid 241300Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL KENTUCKY INTO SOUTHERN OHIO AND WEST VIRGINIA... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this afternoon across portions of the Ohio and Tennessee Valleys into the central/southern Appalachians. A few strong/severe storms are also possible across portions of the southern Plains. ...Ohio and Tennessee Valleys to southern Appalachians... Water-vapor imagery this morning shows a mid-level vorticity maximum moving across the middle MS Valley and into the OH Valley. A belt of moderate to strong southwesterly 500-mb flow (25-50 kt) will overspread KY and the surrounding states, with the strongest flow generally within the Slight Risk bounds. Bands of showers/weak thunderstorms are ongoing this morning from middle TN into OH, and in a separate area over eastern IL immediately ahead of the surface low. This low will migrate east-northeast into southern Lower MI by early evening with a frontal zone extending south-southwest into the Mid South. In wake of the early morning convection, some cloud breaks/destabilization is forecast with upwards of 750-2000 J/kg MLCAPE from the southern Great Lakes into the southern Appalachian states. Ample deep-layer speed shear (via mostly southwesterly flow through the troposphere) will aid in storm organization into organized multicells and probably several supercells. Only notable change this outlook update was to include portions of the southern Great Lakes in low-severe probabilities for potential activity near/ahead of the surface low. The primary concern across the general region will likely be damaging winds with the stronger storms. ...OK vicinity... An amplifying large-scale trough over the MS Valley will feature a 60-kt 500mb speed max moving southward into the central Great Plains by early evening on the backside of the upper trough. Left exit region of this feature will encourage large-scale ascent, and a weak surface wave/low should evolve over southwest KS/northwest OK by early afternoon. Strong heating will contribute to 750-1250 J/kg MLCAPE by mid afternoon across OK with flow veering and strengthening with height. Elongated hodographs will support the potential for hail growth with a few of the stronger/sustained updrafts that evolve. An isolated threat for large hail (1 to 1.75 inches in diameter) and/or severe gusts (60-70 mph) will probably peak during the 23z-03z period before storms weaken during the late evening. ..Smith/Broyles.. 09/24/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0742 AM CDT Tue Sep 24 2024 Valid 241300Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL KENTUCKY INTO SOUTHERN OHIO AND WEST VIRGINIA... ...SUMMARY... Isolated to scattered severe thunderstorms are possible mainly this afternoon across portions of the Ohio and Tennessee Valleys into the central/southern Appalachians. A few strong/severe storms are also possible across portions of the southern Plains. ...Ohio and Tennessee Valleys to southern Appalachians... Water-vapor imagery this morning shows a mid-level vorticity maximum moving across the middle MS Valley and into the OH Valley. A belt of moderate to strong southwesterly 500-mb flow (25-50 kt) will overspread KY and the surrounding states, with the strongest flow generally within the Slight Risk bounds. Bands of showers/weak thunderstorms are ongoing this morning from middle TN into OH, and in a separate area over eastern IL immediately ahead of the surface low. This low will migrate east-northeast into southern Lower MI by early evening with a frontal zone extending south-southwest into the Mid South. In wake of the early morning convection, some cloud breaks/destabilization is forecast with upwards of 750-2000 J/kg MLCAPE from the southern Great Lakes into the southern Appalachian states. Ample deep-layer speed shear (via mostly southwesterly flow through the troposphere) will aid in storm organization into organized multicells and probably several supercells. Only notable change this outlook update was to include portions of the southern Great Lakes in low-severe probabilities for potential activity near/ahead of the surface low. The primary concern across the general region will likely be damaging winds with the stronger storms. ...OK vicinity... An amplifying large-scale trough over the MS Valley will feature a 60-kt 500mb speed max moving southward into the central Great Plains by early evening on the backside of the upper trough. Left exit region of this feature will encourage large-scale ascent, and a weak surface wave/low should evolve over southwest KS/northwest OK by early afternoon. Strong heating will contribute to 750-1250 J/kg MLCAPE by mid afternoon across OK with flow veering and strengthening with height. Elongated hodographs will support the potential for hail growth with a few of the stronger/sustained updrafts that evolve. An isolated threat for large hail (1 to 1.75 inches in diameter) and/or severe gusts (60-70 mph) will probably peak during the 23z-03z period before storms weaken during the late evening. ..Smith/Broyles.. 09/24/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0250 AM CDT Tue Sep 24 2024 Valid 271200Z - 021200Z ...DISCUSSION... A low-end tropical cyclone related tornado risk may continue into Day 4/Fri from parts of the Southeast toward the central Appalachian vicinity. However, spread among medium range guidance is quite large at this time frame regarding the position of the remnant tropical cyclone. Beyond Day 4/Fri, medium range guidance generally maintains an closed upper cyclone across the broader Mid-South and Ohio Valley vicinity through Day 6/Sun before this feature weakens and an open wave trough evolves and progresses east toward the Atlantic coast through early next week. Meanwhile, upper ridging will persist across much of the western half of the CONUS. Overall, severe potential beyond Day 4/Fri appears low given areas of widespread precipitation and cloudiness, along with limited instability and weakening deep-layer flow with time. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0250 AM CDT Tue Sep 24 2024 Valid 271200Z - 021200Z ...DISCUSSION... A low-end tropical cyclone related tornado risk may continue into Day 4/Fri from parts of the Southeast toward the central Appalachian vicinity. However, spread among medium range guidance is quite large at this time frame regarding the position of the remnant tropical cyclone. Beyond Day 4/Fri, medium range guidance generally maintains an closed upper cyclone across the broader Mid-South and Ohio Valley vicinity through Day 6/Sun before this feature weakens and an open wave trough evolves and progresses east toward the Atlantic coast through early next week. Meanwhile, upper ridging will persist across much of the western half of the CONUS. Overall, severe potential beyond Day 4/Fri appears low given areas of widespread precipitation and cloudiness, along with limited instability and weakening deep-layer flow with time. Read more