Severe Storms

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 AM CST Sat Nov 18 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 isolated hail will also be possible. ...Synopsis... A complex mid/upper-level trough is forecast to gradually shift eastward across the central CONUS on Monday. A vigorous shortwave is expected to move through the base of the trough, potentially resulting in consolidation of a mid/upper-level cyclone from eastern portions of the central Plains toward the mid-MS Valley. As this occurs, a surface cyclone initially over the southern Plains is forecast to move eastward toward the lower MS Valley. A trailing cold front will move from east TX toward the ArkLaMiss region by early Tuesday morning. ...East TX into the lower MS Valley and Southeast... Increasingly rich low-level moisture (with dewpoints into the mid/upper 60s F) is expected to advance northward during the day on Monday from east TX into the lower MS Valley, in advance of the surface low and cold front. Modest heating will support moderate buoyancy along/east of the front across east TX, where storm development is possible by late afternoon. Strengthening deep-layer shear will support supercell potential, though there may be a tendency toward more of a cluster or linear mode as storm coverage increases along/ahead of the front into the evening. Initial storm development from east TX toward the ArkLaTex will pose a threat of large hail and locally damaging gusts. With time, the hail threat may tend to decrease, but the tornado threat will increase with any persistent supercells and/or line-embedded mesovortices as low-level shear/SRH strengthens during the evening. Instability will tend to weaken with eastward extent, but any organized storm structures may continue to pose a threat of locally damaging wind and a tornado or two into the overnight, as they move through a moist and strongly sheared environment. While guidance has come into somewhat better agreement regarding the scenario described above, important differences remain with respect to the amplitude and intensity of the basal shortwave trough and attendant surface cyclone. The stronger solutions would support greater low-level mass response, and a greater tornado/wind threat compared to the weaker and less amplified solutions. A rather broad Slight Risk has been maintained with this outlook, in order to account for various plausible scenarios regarding the magnitude and favored corridor of the primary severe risk. ..Dean.. 11/18/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 AM CST Sat Nov 18 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 isolated hail will also be possible. ...Synopsis... A complex mid/upper-level trough is forecast to gradually shift eastward across the central CONUS on Monday. A vigorous shortwave is expected to move through the base of the trough, potentially resulting in consolidation of a mid/upper-level cyclone from eastern portions of the central Plains toward the mid-MS Valley. As this occurs, a surface cyclone initially over the southern Plains is forecast to move eastward toward the lower MS Valley. A trailing cold front will move from east TX toward the ArkLaMiss region by early Tuesday morning. ...East TX into the lower MS Valley and Southeast... Increasingly rich low-level moisture (with dewpoints into the mid/upper 60s F) is expected to advance northward during the day on Monday from east TX into the lower MS Valley, in advance of the surface low and cold front. Modest heating will support moderate buoyancy along/east of the front across east TX, where storm development is possible by late afternoon. Strengthening deep-layer shear will support supercell potential, though there may be a tendency toward more of a cluster or linear mode as storm coverage increases along/ahead of the front into the evening. Initial storm development from east TX toward the ArkLaTex will pose a threat of large hail and locally damaging gusts. With time, the hail threat may tend to decrease, but the tornado threat will increase with any persistent supercells and/or line-embedded mesovortices as low-level shear/SRH strengthens during the evening. Instability will tend to weaken with eastward extent, but any organized storm structures may continue to pose a threat of locally damaging wind and a tornado or two into the overnight, as they move through a moist and strongly sheared environment. While guidance has come into somewhat better agreement regarding the scenario described above, important differences remain with respect to the amplitude and intensity of the basal shortwave trough and attendant surface cyclone. The stronger solutions would support greater low-level mass response, and a greater tornado/wind threat compared to the weaker and less amplified solutions. A rather broad Slight Risk has been maintained with this outlook, in order to account for various plausible scenarios regarding the magnitude and favored corridor of the primary severe risk. ..Dean.. 11/18/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 AM CST Sat Nov 18 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 isolated hail will also be possible. ...Synopsis... A complex mid/upper-level trough is forecast to gradually shift eastward across the central CONUS on Monday. A vigorous shortwave is expected to move through the base of the trough, potentially resulting in consolidation of a mid/upper-level cyclone from eastern portions of the central Plains toward the mid-MS Valley. As this occurs, a surface cyclone initially over the southern Plains is forecast to move eastward toward the lower MS Valley. A trailing cold front will move from east TX toward the ArkLaMiss region by early Tuesday morning. ...East TX into the lower MS Valley and Southeast... Increasingly rich low-level moisture (with dewpoints into the mid/upper 60s F) is expected to advance northward during the day on Monday from east TX into the lower MS Valley, in advance of the surface low and cold front. Modest heating will support moderate buoyancy along/east of the front across east TX, where storm development is possible by late afternoon. Strengthening deep-layer shear will support supercell potential, though there may be a tendency toward more of a cluster or linear mode as storm coverage increases along/ahead of the front into the evening. Initial storm development from east TX toward the ArkLaTex will pose a threat of large hail and locally damaging gusts. With time, the hail threat may tend to decrease, but the tornado threat will increase with any persistent supercells and/or line-embedded mesovortices as low-level shear/SRH strengthens during the evening. Instability will tend to weaken with eastward extent, but any organized storm structures may continue to pose a threat of locally damaging wind and a tornado or two into the overnight, as they move through a moist and strongly sheared environment. While guidance has come into somewhat better agreement regarding the scenario described above, important differences remain with respect to the amplitude and intensity of the basal shortwave trough and attendant surface cyclone. The stronger solutions would support greater low-level mass response, and a greater tornado/wind threat compared to the weaker and less amplified solutions. A rather broad Slight Risk has been maintained with this outlook, in order to account for various plausible scenarios regarding the magnitude and favored corridor of the primary severe risk. ..Dean.. 11/18/2023 Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0223 AM CST Sat Nov 18 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 isolated hail will also be possible. ...Synopsis... A complex mid/upper-level trough is forecast to gradually shift eastward across the central CONUS on Monday. A vigorous shortwave is expected to move through the base of the trough, potentially resulting in consolidation of a mid/upper-level cyclone from eastern portions of the central Plains toward the mid-MS Valley. As this occurs, a surface cyclone initially over the southern Plains is forecast to move eastward toward the lower MS Valley. A trailing cold front will move from east TX toward the ArkLaMiss region by early Tuesday morning. ...East TX into the lower MS Valley and Southeast... Increasingly rich low-level moisture (with dewpoints into the mid/upper 60s F) is expected to advance northward during the day on Monday from east TX into the lower MS Valley, in advance of the surface low and cold front. Modest heating will support moderate buoyancy along/east of the front across east TX, where storm development is possible by late afternoon. Strengthening deep-layer shear will support supercell potential, though there may be a tendency toward more of a cluster or linear mode as storm coverage increases along/ahead of the front into the evening. Initial storm development from east TX toward the ArkLaTex will pose a threat of large hail and locally damaging gusts. With time, the hail threat may tend to decrease, but the tornado threat will increase with any persistent supercells and/or line-embedded mesovortices as low-level shear/SRH strengthens during the evening. Instability will tend to weaken with eastward extent, but any organized storm structures may continue to pose a threat of locally damaging wind and a tornado or two into the overnight, as they move through a moist and strongly sheared environment. While guidance has come into somewhat better agreement regarding the scenario described above, important differences remain with respect to the amplitude and intensity of the basal shortwave trough and attendant surface cyclone. The stronger solutions would support greater low-level mass response, and a greater tornado/wind threat compared to the weaker and less amplified solutions. A rather broad Slight Risk has been maintained with this outlook, in order to account for various plausible scenarios regarding the magnitude and favored corridor of the primary severe risk. ..Dean.. 11/18/2023 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0159 AM CST Sat Nov 18 2023 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... ...Synopsis... A progressive mid-level flow pattern is expected to persist D2/Sunday as an upper trough over the East Coast continues to move offshore. A broad western US trough is expected to amplify through the weekend before ejecting eastward into the central US by the end of the forecast period. Transient surface high pressure will persist over the eastern third of the country in the wake of an earlier cold front. Cooler and drier conditions are possible over parts of the central and southern Appalachians. Occasional gusty winds near the higher terrain may support brief elevated fire-weather conditions within areas of dry fuels across NC and VA. Localized dry and breezy conditions are also possible over parts of eastern NM. However, with only transient overlap of dry and breezy conditions, widespread fire-weather concerns appear low for much of the CONUS. ..Lyons.. 11/18/2023 ...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 0159 AM CST Sat Nov 18 2023 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... ...Synopsis... A progressive mid-level flow pattern is expected to persist D2/Sunday as an upper trough over the East Coast continues to move offshore. A broad western US trough is expected to amplify through the weekend before ejecting eastward into the central US by the end of the forecast period. Transient surface high pressure will persist over the eastern third of the country in the wake of an earlier cold front. Cooler and drier conditions are possible over parts of the central and southern Appalachians. Occasional gusty winds near the higher terrain may support brief elevated fire-weather conditions within areas of dry fuels across NC and VA. Localized dry and breezy conditions are also possible over parts of eastern NM. However, with only transient overlap of dry and breezy conditions, widespread fire-weather concerns appear low for much of the CONUS. ..Lyons.. 11/18/2023 ...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 0159 AM CST Sat Nov 18 2023 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... ...Synopsis... A progressive mid-level flow pattern is expected to persist D2/Sunday as an upper trough over the East Coast continues to move offshore. A broad western US trough is expected to amplify through the weekend before ejecting eastward into the central US by the end of the forecast period. Transient surface high pressure will persist over the eastern third of the country in the wake of an earlier cold front. Cooler and drier conditions are possible over parts of the central and southern Appalachians. Occasional gusty winds near the higher terrain may support brief elevated fire-weather conditions within areas of dry fuels across NC and VA. Localized dry and breezy conditions are also possible over parts of eastern NM. However, with only transient overlap of dry and breezy conditions, widespread fire-weather concerns appear low for much of the CONUS. ..Lyons.. 11/18/2023 ...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 0159 AM CST Sat Nov 18 2023 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... ...Synopsis... A progressive mid-level flow pattern is expected to persist D2/Sunday as an upper trough over the East Coast continues to move offshore. A broad western US trough is expected to amplify through the weekend before ejecting eastward into the central US by the end of the forecast period. Transient surface high pressure will persist over the eastern third of the country in the wake of an earlier cold front. Cooler and drier conditions are possible over parts of the central and southern Appalachians. Occasional gusty winds near the higher terrain may support brief elevated fire-weather conditions within areas of dry fuels across NC and VA. Localized dry and breezy conditions are also possible over parts of eastern NM. However, with only transient overlap of dry and breezy conditions, widespread fire-weather concerns appear low for much of the CONUS. ..Lyons.. 11/18/2023 ...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 0159 AM CST Sat Nov 18 2023 Valid 191200Z - 201200Z ...NO CRITICAL AREAS... ...Synopsis... A progressive mid-level flow pattern is expected to persist D2/Sunday as an upper trough over the East Coast continues to move offshore. A broad western US trough is expected to amplify through the weekend before ejecting eastward into the central US by the end of the forecast period. Transient surface high pressure will persist over the eastern third of the country in the wake of an earlier cold front. Cooler and drier conditions are possible over parts of the central and southern Appalachians. Occasional gusty winds near the higher terrain may support brief elevated fire-weather conditions within areas of dry fuels across NC and VA. Localized dry and breezy conditions are also possible over parts of eastern NM. However, with only transient overlap of dry and breezy conditions, widespread fire-weather concerns appear low for much of the CONUS. ..Lyons.. 11/18/2023 ...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 Sat Nov 18 2023 Valid 181200Z - 191200Z ...Synopsis... Within an active mid-level flow pattern, an upper trough and enhanced cyclonic flow aloft over the eastern states is forecast to maintain intensity while moving slowly offshore. Shortwave ridging over the Midwest will favor surface high pressure within a post-frontal air mass over parts of the upper OH Valley and central Appalachians. Gusty northerly winds will support some localized fire-weather concerns over parts of VA and NC Saturday. ...Western VA and NC... With surface high pressure increasing over the upper OH Valley, a northerly surface pressure gradient should develop steadily through the first part of the day. Gusty downslope winds are possible through the early afternoon across parts of the central Appalachians in western VA and NC. A much drier air mass in the wake of the earlier cold front should support a few hours of lower RH below 30%. Given the state of fuels and recent fire activity, elevated fire-weather concerns are possible over western NC into parts of central VA with dry and breezy conditions. Fire-weather concerns should quickly abate into the evening as winds slacken, though drier air should remain in place through the weekend. ..Lyons.. 11/18/2023 ...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 Sat Nov 18 2023 Valid 181200Z - 191200Z ...Synopsis... Within an active mid-level flow pattern, an upper trough and enhanced cyclonic flow aloft over the eastern states is forecast to maintain intensity while moving slowly offshore. Shortwave ridging over the Midwest will favor surface high pressure within a post-frontal air mass over parts of the upper OH Valley and central Appalachians. Gusty northerly winds will support some localized fire-weather concerns over parts of VA and NC Saturday. ...Western VA and NC... With surface high pressure increasing over the upper OH Valley, a northerly surface pressure gradient should develop steadily through the first part of the day. Gusty downslope winds are possible through the early afternoon across parts of the central Appalachians in western VA and NC. A much drier air mass in the wake of the earlier cold front should support a few hours of lower RH below 30%. Given the state of fuels and recent fire activity, elevated fire-weather concerns are possible over western NC into parts of central VA with dry and breezy conditions. Fire-weather concerns should quickly abate into the evening as winds slacken, though drier air should remain in place through the weekend. ..Lyons.. 11/18/2023 ...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 Sat Nov 18 2023 Valid 181200Z - 191200Z ...Synopsis... Within an active mid-level flow pattern, an upper trough and enhanced cyclonic flow aloft over the eastern states is forecast to maintain intensity while moving slowly offshore. Shortwave ridging over the Midwest will favor surface high pressure within a post-frontal air mass over parts of the upper OH Valley and central Appalachians. Gusty northerly winds will support some localized fire-weather concerns over parts of VA and NC Saturday. ...Western VA and NC... With surface high pressure increasing over the upper OH Valley, a northerly surface pressure gradient should develop steadily through the first part of the day. Gusty downslope winds are possible through the early afternoon across parts of the central Appalachians in western VA and NC. A much drier air mass in the wake of the earlier cold front should support a few hours of lower RH below 30%. Given the state of fuels and recent fire activity, elevated fire-weather concerns are possible over western NC into parts of central VA with dry and breezy conditions. Fire-weather concerns should quickly abate into the evening as winds slacken, though drier air should remain in place through the weekend. ..Lyons.. 11/18/2023 ...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 Sat Nov 18 2023 Valid 181200Z - 191200Z ...Synopsis... Within an active mid-level flow pattern, an upper trough and enhanced cyclonic flow aloft over the eastern states is forecast to maintain intensity while moving slowly offshore. Shortwave ridging over the Midwest will favor surface high pressure within a post-frontal air mass over parts of the upper OH Valley and central Appalachians. Gusty northerly winds will support some localized fire-weather concerns over parts of VA and NC Saturday. ...Western VA and NC... With surface high pressure increasing over the upper OH Valley, a northerly surface pressure gradient should develop steadily through the first part of the day. Gusty downslope winds are possible through the early afternoon across parts of the central Appalachians in western VA and NC. A much drier air mass in the wake of the earlier cold front should support a few hours of lower RH below 30%. Given the state of fuels and recent fire activity, elevated fire-weather concerns are possible over western NC into parts of central VA with dry and breezy conditions. Fire-weather concerns should quickly abate into the evening as winds slacken, though drier air should remain in place through the weekend. ..Lyons.. 11/18/2023 ...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 Sat Nov 18 2023 Valid 181200Z - 191200Z ...Synopsis... Within an active mid-level flow pattern, an upper trough and enhanced cyclonic flow aloft over the eastern states is forecast to maintain intensity while moving slowly offshore. Shortwave ridging over the Midwest will favor surface high pressure within a post-frontal air mass over parts of the upper OH Valley and central Appalachians. Gusty northerly winds will support some localized fire-weather concerns over parts of VA and NC Saturday. ...Western VA and NC... With surface high pressure increasing over the upper OH Valley, a northerly surface pressure gradient should develop steadily through the first part of the day. Gusty downslope winds are possible through the early afternoon across parts of the central Appalachians in western VA and NC. A much drier air mass in the wake of the earlier cold front should support a few hours of lower RH below 30%. Given the state of fuels and recent fire activity, elevated fire-weather concerns are possible over western NC into parts of central VA with dry and breezy conditions. Fire-weather concerns should quickly abate into the evening as winds slacken, though drier air should remain in place through the weekend. ..Lyons.. 11/18/2023 ...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 Sat Nov 18 2023 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF OKLAHOMA... ...SUMMARY... Thunderstorms with a threat of isolated hail may develop across parts of Oklahoma on Sunday. ...Synopsis... A complex mid/upper-level trough is forecast to gradually shift eastward into the central CONUS on Sunday, as an upper ridge builds into the West. Within the large-scale trough, one shortwave is forecast to evolve into a mid/upper-level cyclone somewhere over the north-central Great Plains, as a trailing shortwave moves from the Southwest toward the southern Plains as it pivots through the base of the trough. A third vigorous shortwave is forecast to dig southeastward from the Great Basin toward the Four Corners and eventually the southern Rockies by Monday morning. ...Southern Plains... Modest low-level moisture return is expected across parts of the southern Plains through the day Sunday, as a surface cyclone gradually deepens over the south-central High Plains and a trailing dryline becomes established across far western OK into west-central TX. However, guidance has generally trended toward weaker moisture return during the day, resulting in only minimal destabilization and limited potential for surface-based storm development. While early-day elevated convection will be possible across parts of OK and north TX, and redevelopment of elevated convection may occur during the evening across mainly parts of OK, confidence in the potential for organized severe-thunderstorm development has decreased. The strongest elevated storms could pose a threat of small hail, with a nonzero threat of marginally severe hail across parts of OK, in closer proximity to steeper midlevel lapse rates and colder temperatures aloft. ..Dean.. 11/18/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CST Sat Nov 18 2023 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF OKLAHOMA... ...SUMMARY... Thunderstorms with a threat of isolated hail may develop across parts of Oklahoma on Sunday. ...Synopsis... A complex mid/upper-level trough is forecast to gradually shift eastward into the central CONUS on Sunday, as an upper ridge builds into the West. Within the large-scale trough, one shortwave is forecast to evolve into a mid/upper-level cyclone somewhere over the north-central Great Plains, as a trailing shortwave moves from the Southwest toward the southern Plains as it pivots through the base of the trough. A third vigorous shortwave is forecast to dig southeastward from the Great Basin toward the Four Corners and eventually the southern Rockies by Monday morning. ...Southern Plains... Modest low-level moisture return is expected across parts of the southern Plains through the day Sunday, as a surface cyclone gradually deepens over the south-central High Plains and a trailing dryline becomes established across far western OK into west-central TX. However, guidance has generally trended toward weaker moisture return during the day, resulting in only minimal destabilization and limited potential for surface-based storm development. While early-day elevated convection will be possible across parts of OK and north TX, and redevelopment of elevated convection may occur during the evening across mainly parts of OK, confidence in the potential for organized severe-thunderstorm development has decreased. The strongest elevated storms could pose a threat of small hail, with a nonzero threat of marginally severe hail across parts of OK, in closer proximity to steeper midlevel lapse rates and colder temperatures aloft. ..Dean.. 11/18/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CST Sat Nov 18 2023 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF OKLAHOMA... ...SUMMARY... Thunderstorms with a threat of isolated hail may develop across parts of Oklahoma on Sunday. ...Synopsis... A complex mid/upper-level trough is forecast to gradually shift eastward into the central CONUS on Sunday, as an upper ridge builds into the West. Within the large-scale trough, one shortwave is forecast to evolve into a mid/upper-level cyclone somewhere over the north-central Great Plains, as a trailing shortwave moves from the Southwest toward the southern Plains as it pivots through the base of the trough. A third vigorous shortwave is forecast to dig southeastward from the Great Basin toward the Four Corners and eventually the southern Rockies by Monday morning. ...Southern Plains... Modest low-level moisture return is expected across parts of the southern Plains through the day Sunday, as a surface cyclone gradually deepens over the south-central High Plains and a trailing dryline becomes established across far western OK into west-central TX. However, guidance has generally trended toward weaker moisture return during the day, resulting in only minimal destabilization and limited potential for surface-based storm development. While early-day elevated convection will be possible across parts of OK and north TX, and redevelopment of elevated convection may occur during the evening across mainly parts of OK, confidence in the potential for organized severe-thunderstorm development has decreased. The strongest elevated storms could pose a threat of small hail, with a nonzero threat of marginally severe hail across parts of OK, in closer proximity to steeper midlevel lapse rates and colder temperatures aloft. ..Dean.. 11/18/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CST Sat Nov 18 2023 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF OKLAHOMA... ...SUMMARY... Thunderstorms with a threat of isolated hail may develop across parts of Oklahoma on Sunday. ...Synopsis... A complex mid/upper-level trough is forecast to gradually shift eastward into the central CONUS on Sunday, as an upper ridge builds into the West. Within the large-scale trough, one shortwave is forecast to evolve into a mid/upper-level cyclone somewhere over the north-central Great Plains, as a trailing shortwave moves from the Southwest toward the southern Plains as it pivots through the base of the trough. A third vigorous shortwave is forecast to dig southeastward from the Great Basin toward the Four Corners and eventually the southern Rockies by Monday morning. ...Southern Plains... Modest low-level moisture return is expected across parts of the southern Plains through the day Sunday, as a surface cyclone gradually deepens over the south-central High Plains and a trailing dryline becomes established across far western OK into west-central TX. However, guidance has generally trended toward weaker moisture return during the day, resulting in only minimal destabilization and limited potential for surface-based storm development. While early-day elevated convection will be possible across parts of OK and north TX, and redevelopment of elevated convection may occur during the evening across mainly parts of OK, confidence in the potential for organized severe-thunderstorm development has decreased. The strongest elevated storms could pose a threat of small hail, with a nonzero threat of marginally severe hail across parts of OK, in closer proximity to steeper midlevel lapse rates and colder temperatures aloft. ..Dean.. 11/18/2023 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CST Sat Nov 18 2023 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF OKLAHOMA... ...SUMMARY... Thunderstorms with a threat of isolated hail may develop across parts of Oklahoma on Sunday. ...Synopsis... A complex mid/upper-level trough is forecast to gradually shift eastward into the central CONUS on Sunday, as an upper ridge builds into the West. Within the large-scale trough, one shortwave is forecast to evolve into a mid/upper-level cyclone somewhere over the north-central Great Plains, as a trailing shortwave moves from the Southwest toward the southern Plains as it pivots through the base of the trough. A third vigorous shortwave is forecast to dig southeastward from the Great Basin toward the Four Corners and eventually the southern Rockies by Monday morning. ...Southern Plains... Modest low-level moisture return is expected across parts of the southern Plains through the day Sunday, as a surface cyclone gradually deepens over the south-central High Plains and a trailing dryline becomes established across far western OK into west-central TX. However, guidance has generally trended toward weaker moisture return during the day, resulting in only minimal destabilization and limited potential for surface-based storm development. While early-day elevated convection will be possible across parts of OK and north TX, and redevelopment of elevated convection may occur during the evening across mainly parts of OK, confidence in the potential for organized severe-thunderstorm development has decreased. The strongest elevated storms could pose a threat of small hail, with a nonzero threat of marginally severe hail across parts of OK, in closer proximity to steeper midlevel lapse rates and colder temperatures aloft. ..Dean.. 11/18/2023 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1145 PM CST Fri Nov 17 2023 Valid 181200Z - 191200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are unlikely today. ...Synopsis... An amplified yet progressive upper-air pattern will exist today across the CONUS. A mean upper trough will develop over the eastern states, with southern and northern stream phasing from New England to FL. The cooling aloft across FL could yield a few showers or thunderstorms grazing the eastern coastal areas, but most of the activity is expected to remain offshore. However, northwest surface winds may enhance convergence immediately along the coast and an isolated cell cannot be ruled out. The greatest chance of thunderstorms will develop throughout the period, from parts of the southwest into the southern and central High Plains. ...Southwest/Southern Plains... Height falls will occur over the Four Corners states during the day as a low-amplitude wave enters the southern High Plains late. Storms will be ongoing over AZ this morning, with additional midlevel moistening and lift spreading over NM. Diurnal heating will lead to a few hundred J/kg MUCAPE during the day, with perhaps 500 J/kg of elevated CAPE into KS/OK/northwest TX overnight as a low-level jet strengthens. Forecast sounding over NM and western TX do show long hodographs and strong deep-layer shear. This may actually reduce damaging gust potential as storm mode trends toward cellular with strong storm relative flow aloft removing potential downdraft material. Assuming a cellular mode, the primary risk typically trends toward hail, but instability will be relatively weak in this case. The end result should be scattered storms capable of perhaps strong gusts or small, non-severe hail, and little severe risk. ..Jewell/Lyons.. 11/18/2023 Read more