Aggregator

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CST Sun Nov 19 2023 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... ...Synopsis... A deep upper trough over the Four Corners will begin to move eastward over the Plains and central US through Monday with an accompanying surface low and Pacific front. Very strong mid-level flow will overspread parts of the Southern High Plains, while surface high pressure develops within the Great Basin. Gusty winds are possible over parts of Southern CA and the southern High Plains, but recent rainfall and cooler conditions should keep fire-weather concerns localized. ...Southern Plains... To the east of the deepening Four Corners trough, very strong flow aloft is expected to overspread parts of the Southern High Plains and eastern NM as the upper-level systems begins to move east. Aided by the low over central OK, gusty northwest surface winds are possible across west TX and eastern NM Monday afternoon and evening. However, recent rainfall and cooler temperatures in the wake of the passing Pacific front should keep RH above critical levels. Gusty winds still may support brief local fire-weather concerns before weakening late Monday. ...Southern California... As the main upper trough continues to deepen, strong flow aloft along the backside will overspread parts of southern CA late this weekend into early Monday. High pressure over the Great Basin will tighten offshore surface pressure gradients, enhancing surface winds across Point Conception and the lee of the Peninsular Ranges. A few hours of gusty winds and low humidity are likely through Monday evening before winds begin to weaken into Tuesday morning. However, recent rain and the relatively brief period of offshore winds suggests any fire-weather concerns will remain localized, with only marginally receptive fuels. ..Lyons.. 11/19/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CST Sun Nov 19 2023 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... ...Synopsis... A deep upper trough over the Four Corners will begin to move eastward over the Plains and central US through Monday with an accompanying surface low and Pacific front. Very strong mid-level flow will overspread parts of the Southern High Plains, while surface high pressure develops within the Great Basin. Gusty winds are possible over parts of Southern CA and the southern High Plains, but recent rainfall and cooler conditions should keep fire-weather concerns localized. ...Southern Plains... To the east of the deepening Four Corners trough, very strong flow aloft is expected to overspread parts of the Southern High Plains and eastern NM as the upper-level systems begins to move east. Aided by the low over central OK, gusty northwest surface winds are possible across west TX and eastern NM Monday afternoon and evening. However, recent rainfall and cooler temperatures in the wake of the passing Pacific front should keep RH above critical levels. Gusty winds still may support brief local fire-weather concerns before weakening late Monday. ...Southern California... As the main upper trough continues to deepen, strong flow aloft along the backside will overspread parts of southern CA late this weekend into early Monday. High pressure over the Great Basin will tighten offshore surface pressure gradients, enhancing surface winds across Point Conception and the lee of the Peninsular Ranges. A few hours of gusty winds and low humidity are likely through Monday evening before winds begin to weaken into Tuesday morning. However, recent rain and the relatively brief period of offshore winds suggests any fire-weather concerns will remain localized, with only marginally receptive fuels. ..Lyons.. 11/19/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CST Sun Nov 19 2023 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... ...Synopsis... A deep upper trough over the Four Corners will begin to move eastward over the Plains and central US through Monday with an accompanying surface low and Pacific front. Very strong mid-level flow will overspread parts of the Southern High Plains, while surface high pressure develops within the Great Basin. Gusty winds are possible over parts of Southern CA and the southern High Plains, but recent rainfall and cooler conditions should keep fire-weather concerns localized. ...Southern Plains... To the east of the deepening Four Corners trough, very strong flow aloft is expected to overspread parts of the Southern High Plains and eastern NM as the upper-level systems begins to move east. Aided by the low over central OK, gusty northwest surface winds are possible across west TX and eastern NM Monday afternoon and evening. However, recent rainfall and cooler temperatures in the wake of the passing Pacific front should keep RH above critical levels. Gusty winds still may support brief local fire-weather concerns before weakening late Monday. ...Southern California... As the main upper trough continues to deepen, strong flow aloft along the backside will overspread parts of southern CA late this weekend into early Monday. High pressure over the Great Basin will tighten offshore surface pressure gradients, enhancing surface winds across Point Conception and the lee of the Peninsular Ranges. A few hours of gusty winds and low humidity are likely through Monday evening before winds begin to weaken into Tuesday morning. However, recent rain and the relatively brief period of offshore winds suggests any fire-weather concerns will remain localized, with only marginally receptive fuels. ..Lyons.. 11/19/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CST Sun Nov 19 2023 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... ...Synopsis... A deep upper trough over the Four Corners will begin to move eastward over the Plains and central US through Monday with an accompanying surface low and Pacific front. Very strong mid-level flow will overspread parts of the Southern High Plains, while surface high pressure develops within the Great Basin. Gusty winds are possible over parts of Southern CA and the southern High Plains, but recent rainfall and cooler conditions should keep fire-weather concerns localized. ...Southern Plains... To the east of the deepening Four Corners trough, very strong flow aloft is expected to overspread parts of the Southern High Plains and eastern NM as the upper-level systems begins to move east. Aided by the low over central OK, gusty northwest surface winds are possible across west TX and eastern NM Monday afternoon and evening. However, recent rainfall and cooler temperatures in the wake of the passing Pacific front should keep RH above critical levels. Gusty winds still may support brief local fire-weather concerns before weakening late Monday. ...Southern California... As the main upper trough continues to deepen, strong flow aloft along the backside will overspread parts of southern CA late this weekend into early Monday. High pressure over the Great Basin will tighten offshore surface pressure gradients, enhancing surface winds across Point Conception and the lee of the Peninsular Ranges. A few hours of gusty winds and low humidity are likely through Monday evening before winds begin to weaken into Tuesday morning. However, recent rain and the relatively brief period of offshore winds suggests any fire-weather concerns will remain localized, with only marginally receptive fuels. ..Lyons.. 11/19/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0200 AM CST Sun Nov 19 2023 Valid 201200Z - 211200Z ...NO CRITICAL AREAS... ...Synopsis... A deep upper trough over the Four Corners will begin to move eastward over the Plains and central US through Monday with an accompanying surface low and Pacific front. Very strong mid-level flow will overspread parts of the Southern High Plains, while surface high pressure develops within the Great Basin. Gusty winds are possible over parts of Southern CA and the southern High Plains, but recent rainfall and cooler conditions should keep fire-weather concerns localized. ...Southern Plains... To the east of the deepening Four Corners trough, very strong flow aloft is expected to overspread parts of the Southern High Plains and eastern NM as the upper-level systems begins to move east. Aided by the low over central OK, gusty northwest surface winds are possible across west TX and eastern NM Monday afternoon and evening. However, recent rainfall and cooler temperatures in the wake of the passing Pacific front should keep RH above critical levels. Gusty winds still may support brief local fire-weather concerns before weakening late Monday. ...Southern California... As the main upper trough continues to deepen, strong flow aloft along the backside will overspread parts of southern CA late this weekend into early Monday. High pressure over the Great Basin will tighten offshore surface pressure gradients, enhancing surface winds across Point Conception and the lee of the Peninsular Ranges. A few hours of gusty winds and low humidity are likely through Monday evening before winds begin to weaken into Tuesday morning. However, recent rain and the relatively brief period of offshore winds suggests any fire-weather concerns will remain localized, with only marginally receptive fuels. ..Lyons.. 11/19/2023 ...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 0156 AM CST Sun Nov 19 2023 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... ...Synopsis... A broad western US trough is forecast to amplify considerably through the period as it digs southeastward toward the Four Corners later tonight. Strong mid-level flow along the back of the trough will move onshore over the West Coast as Pacific ridging intensifies farther west. Surface high pressure will intensify over the northern Great Basin, helping to strengthen surface pressure gradients over parts of southern CA late tonight into early Monday. Gusty winds are possible over parts of southern CA and the lower CO River Valley. However, recent precipitation and only modest RH decreases should keep fire-weather concerns low. Fire-weather concerns are also expected to remain localized across the southern Appalachians and TN Valley where high pressure will support dry surface conditions, but weak winds. ..Lyons.. 11/19/2023 ...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 0156 AM CST Sun Nov 19 2023 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... ...Synopsis... A broad western US trough is forecast to amplify considerably through the period as it digs southeastward toward the Four Corners later tonight. Strong mid-level flow along the back of the trough will move onshore over the West Coast as Pacific ridging intensifies farther west. Surface high pressure will intensify over the northern Great Basin, helping to strengthen surface pressure gradients over parts of southern CA late tonight into early Monday. Gusty winds are possible over parts of southern CA and the lower CO River Valley. However, recent precipitation and only modest RH decreases should keep fire-weather concerns low. Fire-weather concerns are also expected to remain localized across the southern Appalachians and TN Valley where high pressure will support dry surface conditions, but weak winds. ..Lyons.. 11/19/2023 ...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 0156 AM CST Sun Nov 19 2023 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... ...Synopsis... A broad western US trough is forecast to amplify considerably through the period as it digs southeastward toward the Four Corners later tonight. Strong mid-level flow along the back of the trough will move onshore over the West Coast as Pacific ridging intensifies farther west. Surface high pressure will intensify over the northern Great Basin, helping to strengthen surface pressure gradients over parts of southern CA late tonight into early Monday. Gusty winds are possible over parts of southern CA and the lower CO River Valley. However, recent precipitation and only modest RH decreases should keep fire-weather concerns low. Fire-weather concerns are also expected to remain localized across the southern Appalachians and TN Valley where high pressure will support dry surface conditions, but weak winds. ..Lyons.. 11/19/2023 ...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 0156 AM CST Sun Nov 19 2023 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... ...Synopsis... A broad western US trough is forecast to amplify considerably through the period as it digs southeastward toward the Four Corners later tonight. Strong mid-level flow along the back of the trough will move onshore over the West Coast as Pacific ridging intensifies farther west. Surface high pressure will intensify over the northern Great Basin, helping to strengthen surface pressure gradients over parts of southern CA late tonight into early Monday. Gusty winds are possible over parts of southern CA and the lower CO River Valley. However, recent precipitation and only modest RH decreases should keep fire-weather concerns low. Fire-weather concerns are also expected to remain localized across the southern Appalachians and TN Valley where high pressure will support dry surface conditions, but weak winds. ..Lyons.. 11/19/2023 ...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 0156 AM CST Sun Nov 19 2023 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... ...Synopsis... A broad western US trough is forecast to amplify considerably through the period as it digs southeastward toward the Four Corners later tonight. Strong mid-level flow along the back of the trough will move onshore over the West Coast as Pacific ridging intensifies farther west. Surface high pressure will intensify over the northern Great Basin, helping to strengthen surface pressure gradients over parts of southern CA late tonight into early Monday. Gusty winds are possible over parts of southern CA and the lower CO River Valley. However, recent precipitation and only modest RH decreases should keep fire-weather concerns low. Fire-weather concerns are also expected to remain localized across the southern Appalachians and TN Valley where high pressure will support dry surface conditions, but weak winds. ..Lyons.. 11/19/2023 ...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 0156 AM CST Sun Nov 19 2023 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... ...Synopsis... A broad western US trough is forecast to amplify considerably through the period as it digs southeastward toward the Four Corners later tonight. Strong mid-level flow along the back of the trough will move onshore over the West Coast as Pacific ridging intensifies farther west. Surface high pressure will intensify over the northern Great Basin, helping to strengthen surface pressure gradients over parts of southern CA late tonight into early Monday. Gusty winds are possible over parts of southern CA and the lower CO River Valley. However, recent precipitation and only modest RH decreases should keep fire-weather concerns low. Fire-weather concerns are also expected to remain localized across the southern Appalachians and TN Valley where high pressure will support dry surface conditions, but weak winds. ..Lyons.. 11/19/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CST Sun Nov 19 2023 Valid 201200Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EAST TEXAS INTO PARTS OF THE LOWER MISSISSIPPI VALLEY AND SOUTHEAST... ...SUMMARY... Severe thunderstorms will be possible Monday afternoon into Monday night from east Texas into parts of the lower Mississippi Valley and Southeast. Damaging wind and a few tornadoes are expected to be the primary hazards, though some hail will also be possible. ...Synopsis... A complex mid/upper-level trough will gradually shift eastward across the central CONUS on Monday, as a vigorous vorticity maximum and related mid/upper-level jet move through the base of the trough from the southern Plains into the lower/mid MS Valley. A surface cyclone initially over OK is forecast to move eastward toward the lower MS Valley during the day, then northeastward toward the lower OH Valley Monday night. Relatively rich low-level moisture will stream northward in advance of the cyclone and trailing cold front, with mid/upper 60s F dewpoints becoming established across east TX into LA during the day, and into parts of MS and western AL by Monday evening into the overnight. ...East TX/ArkLaTex into the lower MS Valley and Southeast... Thunderstorms capable of all severe hazards will be possible from east TX into the lower MS Valley Monday afternoon and evening, but uncertainties remain regarding favored corridors of greater threat and the longevity of the threat Monday night within a lower CAPE (but high shear) environment. Modest heating of an increasingly moist environment will support prefrontal MLCAPE approaching 1000 J/kg Monday afternoon from near the ArkLaTex region southward across east TX. Scattered thunderstorm development will be possible near the surface low and cold front, and also potentially within an increasingly moist prefrontal warm sector. Wind profiles may initially be rather unidirectional, but strong mid/upper-level flow will support effective shear of 50-60 kt, more than sufficient for supercells. Large hail and locally damaging gusts will be the primary initial threats. Some tornado threat will potentially evolve with any persistent supercells as low-level shear/SRH generally increases with time. A transition to more of a cluster or linear mode is expected as storms move east-northeastward and increase in coverage across the ArkLaMiss region, with some increase in damaging-wind potential. Some tornado threat may continue into Monday night as well, in association with any persistent supercells and/or stronger line-embedded mesovortices. The severe threat may persist as far east as western AL, though a gradual decreasing trend is expected with time and eastward extent, as the surface cyclone and stronger large-scale ascent move northeastward away from the warm sector early Tuesday morning. A broad Slight Risk has been maintained with this outlook, though a corridor of somewhat greater tornado/wind threat may eventually evolve within this area, including the potential for a strong tornado. Due to lingering uncertainties regarding the strength of low-level mass response and the extent of sufficient instability, confidence remains too low for greater unconditional probabilities at this time. ..Dean.. 11/19/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CST Sun Nov 19 2023 Valid 201200Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EAST TEXAS INTO PARTS OF THE LOWER MISSISSIPPI VALLEY AND SOUTHEAST... ...SUMMARY... Severe thunderstorms will be possible Monday afternoon into Monday night from east Texas into parts of the lower Mississippi Valley and Southeast. Damaging wind and a few tornadoes are expected to be the primary hazards, though some hail will also be possible. ...Synopsis... A complex mid/upper-level trough will gradually shift eastward across the central CONUS on Monday, as a vigorous vorticity maximum and related mid/upper-level jet move through the base of the trough from the southern Plains into the lower/mid MS Valley. A surface cyclone initially over OK is forecast to move eastward toward the lower MS Valley during the day, then northeastward toward the lower OH Valley Monday night. Relatively rich low-level moisture will stream northward in advance of the cyclone and trailing cold front, with mid/upper 60s F dewpoints becoming established across east TX into LA during the day, and into parts of MS and western AL by Monday evening into the overnight. ...East TX/ArkLaTex into the lower MS Valley and Southeast... Thunderstorms capable of all severe hazards will be possible from east TX into the lower MS Valley Monday afternoon and evening, but uncertainties remain regarding favored corridors of greater threat and the longevity of the threat Monday night within a lower CAPE (but high shear) environment. Modest heating of an increasingly moist environment will support prefrontal MLCAPE approaching 1000 J/kg Monday afternoon from near the ArkLaTex region southward across east TX. Scattered thunderstorm development will be possible near the surface low and cold front, and also potentially within an increasingly moist prefrontal warm sector. Wind profiles may initially be rather unidirectional, but strong mid/upper-level flow will support effective shear of 50-60 kt, more than sufficient for supercells. Large hail and locally damaging gusts will be the primary initial threats. Some tornado threat will potentially evolve with any persistent supercells as low-level shear/SRH generally increases with time. A transition to more of a cluster or linear mode is expected as storms move east-northeastward and increase in coverage across the ArkLaMiss region, with some increase in damaging-wind potential. Some tornado threat may continue into Monday night as well, in association with any persistent supercells and/or stronger line-embedded mesovortices. The severe threat may persist as far east as western AL, though a gradual decreasing trend is expected with time and eastward extent, as the surface cyclone and stronger large-scale ascent move northeastward away from the warm sector early Tuesday morning. A broad Slight Risk has been maintained with this outlook, though a corridor of somewhat greater tornado/wind threat may eventually evolve within this area, including the potential for a strong tornado. Due to lingering uncertainties regarding the strength of low-level mass response and the extent of sufficient instability, confidence remains too low for greater unconditional probabilities at this time. ..Dean.. 11/19/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CST Sun Nov 19 2023 Valid 201200Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EAST TEXAS INTO PARTS OF THE LOWER MISSISSIPPI VALLEY AND SOUTHEAST... ...SUMMARY... Severe thunderstorms will be possible Monday afternoon into Monday night from east Texas into parts of the lower Mississippi Valley and Southeast. Damaging wind and a few tornadoes are expected to be the primary hazards, though some hail will also be possible. ...Synopsis... A complex mid/upper-level trough will gradually shift eastward across the central CONUS on Monday, as a vigorous vorticity maximum and related mid/upper-level jet move through the base of the trough from the southern Plains into the lower/mid MS Valley. A surface cyclone initially over OK is forecast to move eastward toward the lower MS Valley during the day, then northeastward toward the lower OH Valley Monday night. Relatively rich low-level moisture will stream northward in advance of the cyclone and trailing cold front, with mid/upper 60s F dewpoints becoming established across east TX into LA during the day, and into parts of MS and western AL by Monday evening into the overnight. ...East TX/ArkLaTex into the lower MS Valley and Southeast... Thunderstorms capable of all severe hazards will be possible from east TX into the lower MS Valley Monday afternoon and evening, but uncertainties remain regarding favored corridors of greater threat and the longevity of the threat Monday night within a lower CAPE (but high shear) environment. Modest heating of an increasingly moist environment will support prefrontal MLCAPE approaching 1000 J/kg Monday afternoon from near the ArkLaTex region southward across east TX. Scattered thunderstorm development will be possible near the surface low and cold front, and also potentially within an increasingly moist prefrontal warm sector. Wind profiles may initially be rather unidirectional, but strong mid/upper-level flow will support effective shear of 50-60 kt, more than sufficient for supercells. Large hail and locally damaging gusts will be the primary initial threats. Some tornado threat will potentially evolve with any persistent supercells as low-level shear/SRH generally increases with time. A transition to more of a cluster or linear mode is expected as storms move east-northeastward and increase in coverage across the ArkLaMiss region, with some increase in damaging-wind potential. Some tornado threat may continue into Monday night as well, in association with any persistent supercells and/or stronger line-embedded mesovortices. The severe threat may persist as far east as western AL, though a gradual decreasing trend is expected with time and eastward extent, as the surface cyclone and stronger large-scale ascent move northeastward away from the warm sector early Tuesday morning. A broad Slight Risk has been maintained with this outlook, though a corridor of somewhat greater tornado/wind threat may eventually evolve within this area, including the potential for a strong tornado. Due to lingering uncertainties regarding the strength of low-level mass response and the extent of sufficient instability, confidence remains too low for greater unconditional probabilities at this time. ..Dean.. 11/19/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CST Sun Nov 19 2023 Valid 201200Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EAST TEXAS INTO PARTS OF THE LOWER MISSISSIPPI VALLEY AND SOUTHEAST... ...SUMMARY... Severe thunderstorms will be possible Monday afternoon into Monday night from east Texas into parts of the lower Mississippi Valley and Southeast. Damaging wind and a few tornadoes are expected to be the primary hazards, though some hail will also be possible. ...Synopsis... A complex mid/upper-level trough will gradually shift eastward across the central CONUS on Monday, as a vigorous vorticity maximum and related mid/upper-level jet move through the base of the trough from the southern Plains into the lower/mid MS Valley. A surface cyclone initially over OK is forecast to move eastward toward the lower MS Valley during the day, then northeastward toward the lower OH Valley Monday night. Relatively rich low-level moisture will stream northward in advance of the cyclone and trailing cold front, with mid/upper 60s F dewpoints becoming established across east TX into LA during the day, and into parts of MS and western AL by Monday evening into the overnight. ...East TX/ArkLaTex into the lower MS Valley and Southeast... Thunderstorms capable of all severe hazards will be possible from east TX into the lower MS Valley Monday afternoon and evening, but uncertainties remain regarding favored corridors of greater threat and the longevity of the threat Monday night within a lower CAPE (but high shear) environment. Modest heating of an increasingly moist environment will support prefrontal MLCAPE approaching 1000 J/kg Monday afternoon from near the ArkLaTex region southward across east TX. Scattered thunderstorm development will be possible near the surface low and cold front, and also potentially within an increasingly moist prefrontal warm sector. Wind profiles may initially be rather unidirectional, but strong mid/upper-level flow will support effective shear of 50-60 kt, more than sufficient for supercells. Large hail and locally damaging gusts will be the primary initial threats. Some tornado threat will potentially evolve with any persistent supercells as low-level shear/SRH generally increases with time. A transition to more of a cluster or linear mode is expected as storms move east-northeastward and increase in coverage across the ArkLaMiss region, with some increase in damaging-wind potential. Some tornado threat may continue into Monday night as well, in association with any persistent supercells and/or stronger line-embedded mesovortices. The severe threat may persist as far east as western AL, though a gradual decreasing trend is expected with time and eastward extent, as the surface cyclone and stronger large-scale ascent move northeastward away from the warm sector early Tuesday morning. A broad Slight Risk has been maintained with this outlook, though a corridor of somewhat greater tornado/wind threat may eventually evolve within this area, including the potential for a strong tornado. Due to lingering uncertainties regarding the strength of low-level mass response and the extent of sufficient instability, confidence remains too low for greater unconditional probabilities at this time. ..Dean.. 11/19/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CST Sun Nov 19 2023 Valid 201200Z - 211200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EAST TEXAS INTO PARTS OF THE LOWER MISSISSIPPI VALLEY AND SOUTHEAST... ...SUMMARY... Severe thunderstorms will be possible Monday afternoon into Monday night from east Texas into parts of the lower Mississippi Valley and Southeast. Damaging wind and a few tornadoes are expected to be the primary hazards, though some hail will also be possible. ...Synopsis... A complex mid/upper-level trough will gradually shift eastward across the central CONUS on Monday, as a vigorous vorticity maximum and related mid/upper-level jet move through the base of the trough from the southern Plains into the lower/mid MS Valley. A surface cyclone initially over OK is forecast to move eastward toward the lower MS Valley during the day, then northeastward toward the lower OH Valley Monday night. Relatively rich low-level moisture will stream northward in advance of the cyclone and trailing cold front, with mid/upper 60s F dewpoints becoming established across east TX into LA during the day, and into parts of MS and western AL by Monday evening into the overnight. ...East TX/ArkLaTex into the lower MS Valley and Southeast... Thunderstorms capable of all severe hazards will be possible from east TX into the lower MS Valley Monday afternoon and evening, but uncertainties remain regarding favored corridors of greater threat and the longevity of the threat Monday night within a lower CAPE (but high shear) environment. Modest heating of an increasingly moist environment will support prefrontal MLCAPE approaching 1000 J/kg Monday afternoon from near the ArkLaTex region southward across east TX. Scattered thunderstorm development will be possible near the surface low and cold front, and also potentially within an increasingly moist prefrontal warm sector. Wind profiles may initially be rather unidirectional, but strong mid/upper-level flow will support effective shear of 50-60 kt, more than sufficient for supercells. Large hail and locally damaging gusts will be the primary initial threats. Some tornado threat will potentially evolve with any persistent supercells as low-level shear/SRH generally increases with time. A transition to more of a cluster or linear mode is expected as storms move east-northeastward and increase in coverage across the ArkLaMiss region, with some increase in damaging-wind potential. Some tornado threat may continue into Monday night as well, in association with any persistent supercells and/or stronger line-embedded mesovortices. The severe threat may persist as far east as western AL, though a gradual decreasing trend is expected with time and eastward extent, as the surface cyclone and stronger large-scale ascent move northeastward away from the warm sector early Tuesday morning. A broad Slight Risk has been maintained with this outlook, though a corridor of somewhat greater tornado/wind threat may eventually evolve within this area, including the potential for a strong tornado. Due to lingering uncertainties regarding the strength of low-level mass response and the extent of sufficient instability, confidence remains too low for greater unconditional probabilities at this time. ..Dean.. 11/19/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1155 PM CST Sat Nov 18 2023 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF CENTRAL AND NORTHEASTERN OKLAHOMA... ...SUMMARY... A couple of strong thunderstorms may develop across parts of central and northeastern Oklahoma this evening and overnight. The strongest of these storms may produce marginally severe hail. ...Synopsis... In the mid levels, a lead shortwave trough over the Rockies will move eastward over the southern Plains early this morning ahead of a second subtle wave across central NM. At the same time, a much stronger trough and 80-90 kt mid-level jet are forecast to dig southeastward over the Four Corners, while shortwave ridging intensifies over the central CONUS. The lead shortwave should merge with the approaching secondary trough, rapidly amplifying the general flow pattern over the western third of the CONUS. Strong mid-level flow spilling over the Rockies will aid in lee cyclogenesis, with a 1000-1004 mb cyclone expected to develop over parts of central OK by this evening. Intensifying surface wind fields ahead of the deepening trough will draw modest moisture northward across parts of TX and southern OK this evening. The upper trough will begin to move eastward and intensify further into a closed low over the southern Plains late tonight into early Monday. ...Central and northeastern Oklahoma... As the first in a series of shortwave troughs passes over the southern Plains early this morning, low-level warm advection is forecast to intensify ahead of the lee low and developing dryline/ surface trough. Northward advection of the modestly moist surface air mass over western/central TX and southern OK will intensify, with widespread showers and isolated embedded thunderstorms across the southern Plains likely to start the forecast period. Sustained isotropic ascent is also expected to bring widespread cloud cover limiting diurnal heating and available buoyancy for much of the day. Elevated convection should gradually expand northward across KS and the central Plains through the day as the lead shortwave and ascent lift north with it. Stronger height falls aloft, increasing differential thermal advection and the subsequent development of weak buoyancy is expected later this evening and through the overnight hours as the main shortwave trough begins to eject eastward. -20C 500 mb temps should support steepening lapse rates of 7-8 C/km sufficient for approximately 500-750 J/kg of MUCAPE over OK. Elevated atop a sizable surface inversion, isolated thunderstorms are possible over parts of central and eastern OK after 00z continuing through the overnight hours. 50-60 kt of mid-level flow and elongated hodographs may support brief organization into transient supercell structures or clusters. Isolated hail, some of which may be marginally severe, is possible over central and eastern OK immediately ahead of the cold core aloft where buoyancy is expected to be the largest. Confidence in storm coverage and organization however is very low owing to the paltry buoyancy, limited moisture depth and poor diurnal phasing of the upper-level trough. ..Lyons/Jewell.. 11/19/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1155 PM CST Sat Nov 18 2023 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF CENTRAL AND NORTHEASTERN OKLAHOMA... ...SUMMARY... A couple of strong thunderstorms may develop across parts of central and northeastern Oklahoma this evening and overnight. The strongest of these storms may produce marginally severe hail. ...Synopsis... In the mid levels, a lead shortwave trough over the Rockies will move eastward over the southern Plains early this morning ahead of a second subtle wave across central NM. At the same time, a much stronger trough and 80-90 kt mid-level jet are forecast to dig southeastward over the Four Corners, while shortwave ridging intensifies over the central CONUS. The lead shortwave should merge with the approaching secondary trough, rapidly amplifying the general flow pattern over the western third of the CONUS. Strong mid-level flow spilling over the Rockies will aid in lee cyclogenesis, with a 1000-1004 mb cyclone expected to develop over parts of central OK by this evening. Intensifying surface wind fields ahead of the deepening trough will draw modest moisture northward across parts of TX and southern OK this evening. The upper trough will begin to move eastward and intensify further into a closed low over the southern Plains late tonight into early Monday. ...Central and northeastern Oklahoma... As the first in a series of shortwave troughs passes over the southern Plains early this morning, low-level warm advection is forecast to intensify ahead of the lee low and developing dryline/ surface trough. Northward advection of the modestly moist surface air mass over western/central TX and southern OK will intensify, with widespread showers and isolated embedded thunderstorms across the southern Plains likely to start the forecast period. Sustained isotropic ascent is also expected to bring widespread cloud cover limiting diurnal heating and available buoyancy for much of the day. Elevated convection should gradually expand northward across KS and the central Plains through the day as the lead shortwave and ascent lift north with it. Stronger height falls aloft, increasing differential thermal advection and the subsequent development of weak buoyancy is expected later this evening and through the overnight hours as the main shortwave trough begins to eject eastward. -20C 500 mb temps should support steepening lapse rates of 7-8 C/km sufficient for approximately 500-750 J/kg of MUCAPE over OK. Elevated atop a sizable surface inversion, isolated thunderstorms are possible over parts of central and eastern OK after 00z continuing through the overnight hours. 50-60 kt of mid-level flow and elongated hodographs may support brief organization into transient supercell structures or clusters. Isolated hail, some of which may be marginally severe, is possible over central and eastern OK immediately ahead of the cold core aloft where buoyancy is expected to be the largest. Confidence in storm coverage and organization however is very low owing to the paltry buoyancy, limited moisture depth and poor diurnal phasing of the upper-level trough. ..Lyons/Jewell.. 11/19/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1155 PM CST Sat Nov 18 2023 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF CENTRAL AND NORTHEASTERN OKLAHOMA... ...SUMMARY... A couple of strong thunderstorms may develop across parts of central and northeastern Oklahoma this evening and overnight. The strongest of these storms may produce marginally severe hail. ...Synopsis... In the mid levels, a lead shortwave trough over the Rockies will move eastward over the southern Plains early this morning ahead of a second subtle wave across central NM. At the same time, a much stronger trough and 80-90 kt mid-level jet are forecast to dig southeastward over the Four Corners, while shortwave ridging intensifies over the central CONUS. The lead shortwave should merge with the approaching secondary trough, rapidly amplifying the general flow pattern over the western third of the CONUS. Strong mid-level flow spilling over the Rockies will aid in lee cyclogenesis, with a 1000-1004 mb cyclone expected to develop over parts of central OK by this evening. Intensifying surface wind fields ahead of the deepening trough will draw modest moisture northward across parts of TX and southern OK this evening. The upper trough will begin to move eastward and intensify further into a closed low over the southern Plains late tonight into early Monday. ...Central and northeastern Oklahoma... As the first in a series of shortwave troughs passes over the southern Plains early this morning, low-level warm advection is forecast to intensify ahead of the lee low and developing dryline/ surface trough. Northward advection of the modestly moist surface air mass over western/central TX and southern OK will intensify, with widespread showers and isolated embedded thunderstorms across the southern Plains likely to start the forecast period. Sustained isotropic ascent is also expected to bring widespread cloud cover limiting diurnal heating and available buoyancy for much of the day. Elevated convection should gradually expand northward across KS and the central Plains through the day as the lead shortwave and ascent lift north with it. Stronger height falls aloft, increasing differential thermal advection and the subsequent development of weak buoyancy is expected later this evening and through the overnight hours as the main shortwave trough begins to eject eastward. -20C 500 mb temps should support steepening lapse rates of 7-8 C/km sufficient for approximately 500-750 J/kg of MUCAPE over OK. Elevated atop a sizable surface inversion, isolated thunderstorms are possible over parts of central and eastern OK after 00z continuing through the overnight hours. 50-60 kt of mid-level flow and elongated hodographs may support brief organization into transient supercell structures or clusters. Isolated hail, some of which may be marginally severe, is possible over central and eastern OK immediately ahead of the cold core aloft where buoyancy is expected to be the largest. Confidence in storm coverage and organization however is very low owing to the paltry buoyancy, limited moisture depth and poor diurnal phasing of the upper-level trough. ..Lyons/Jewell.. 11/19/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1155 PM CST Sat Nov 18 2023 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF CENTRAL AND NORTHEASTERN OKLAHOMA... ...SUMMARY... A couple of strong thunderstorms may develop across parts of central and northeastern Oklahoma this evening and overnight. The strongest of these storms may produce marginally severe hail. ...Synopsis... In the mid levels, a lead shortwave trough over the Rockies will move eastward over the southern Plains early this morning ahead of a second subtle wave across central NM. At the same time, a much stronger trough and 80-90 kt mid-level jet are forecast to dig southeastward over the Four Corners, while shortwave ridging intensifies over the central CONUS. The lead shortwave should merge with the approaching secondary trough, rapidly amplifying the general flow pattern over the western third of the CONUS. Strong mid-level flow spilling over the Rockies will aid in lee cyclogenesis, with a 1000-1004 mb cyclone expected to develop over parts of central OK by this evening. Intensifying surface wind fields ahead of the deepening trough will draw modest moisture northward across parts of TX and southern OK this evening. The upper trough will begin to move eastward and intensify further into a closed low over the southern Plains late tonight into early Monday. ...Central and northeastern Oklahoma... As the first in a series of shortwave troughs passes over the southern Plains early this morning, low-level warm advection is forecast to intensify ahead of the lee low and developing dryline/ surface trough. Northward advection of the modestly moist surface air mass over western/central TX and southern OK will intensify, with widespread showers and isolated embedded thunderstorms across the southern Plains likely to start the forecast period. Sustained isotropic ascent is also expected to bring widespread cloud cover limiting diurnal heating and available buoyancy for much of the day. Elevated convection should gradually expand northward across KS and the central Plains through the day as the lead shortwave and ascent lift north with it. Stronger height falls aloft, increasing differential thermal advection and the subsequent development of weak buoyancy is expected later this evening and through the overnight hours as the main shortwave trough begins to eject eastward. -20C 500 mb temps should support steepening lapse rates of 7-8 C/km sufficient for approximately 500-750 J/kg of MUCAPE over OK. Elevated atop a sizable surface inversion, isolated thunderstorms are possible over parts of central and eastern OK after 00z continuing through the overnight hours. 50-60 kt of mid-level flow and elongated hodographs may support brief organization into transient supercell structures or clusters. Isolated hail, some of which may be marginally severe, is possible over central and eastern OK immediately ahead of the cold core aloft where buoyancy is expected to be the largest. Confidence in storm coverage and organization however is very low owing to the paltry buoyancy, limited moisture depth and poor diurnal phasing of the upper-level trough. ..Lyons/Jewell.. 11/19/2023 Read more