Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0150 AM CST Mon Dec 16 2024 Valid 171200Z - 181200Z ...Synopsis... Quasi zonal mid-level flow is expected to quickly amplify as ridging develops over the Western US D2/Tues. In the wake of a cold front moving across the central US the day prior, surface high pressure will quickly build over the Great Basin. The high pressure will allow for moderate offshore winds and elevated to near-critical fire-weather concerns over portions of southern CA. ...Southern California... As high pressure intensifies behind the cold front across the Great Basin and interior West, moderate offshore flow is expected to develop D2/Tues into D3/Wed. Santa Ana winds of 15-25 mph will overlap with low RH values of 10-20% across parts of Los Angeles and Ventura counties for several hours. Elevated to near-critical fire-weather conditions appear likely amid dry fuels across portions of southern CA, particularly overnight D2/Tues into D3/Wed. Some uncertainty remains regarding the strength of the winds and minimum RH values in the absence of stronger upper-level support. The best overlap of strong winds and low RH is expected late D2/Tues into early D3/Wed morning. However, if winds trend stronger and earlier as some guidance suggests, critical highlights may be needed sooner. ..Lyons.. 12/16/2024 ...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 0150 AM CST Mon Dec 16 2024 Valid 171200Z - 181200Z ...Synopsis... Quasi zonal mid-level flow is expected to quickly amplify as ridging develops over the Western US D2/Tues. In the wake of a cold front moving across the central US the day prior, surface high pressure will quickly build over the Great Basin. The high pressure will allow for moderate offshore winds and elevated to near-critical fire-weather concerns over portions of southern CA. ...Southern California... As high pressure intensifies behind the cold front across the Great Basin and interior West, moderate offshore flow is expected to develop D2/Tues into D3/Wed. Santa Ana winds of 15-25 mph will overlap with low RH values of 10-20% across parts of Los Angeles and Ventura counties for several hours. Elevated to near-critical fire-weather conditions appear likely amid dry fuels across portions of southern CA, particularly overnight D2/Tues into D3/Wed. Some uncertainty remains regarding the strength of the winds and minimum RH values in the absence of stronger upper-level support. The best overlap of strong winds and low RH is expected late D2/Tues into early D3/Wed morning. However, if winds trend stronger and earlier as some guidance suggests, critical highlights may be needed sooner. ..Lyons.. 12/16/2024 ...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 0150 AM CST Mon Dec 16 2024 Valid 171200Z - 181200Z ...Synopsis... Quasi zonal mid-level flow is expected to quickly amplify as ridging develops over the Western US D2/Tues. In the wake of a cold front moving across the central US the day prior, surface high pressure will quickly build over the Great Basin. The high pressure will allow for moderate offshore winds and elevated to near-critical fire-weather concerns over portions of southern CA. ...Southern California... As high pressure intensifies behind the cold front across the Great Basin and interior West, moderate offshore flow is expected to develop D2/Tues into D3/Wed. Santa Ana winds of 15-25 mph will overlap with low RH values of 10-20% across parts of Los Angeles and Ventura counties for several hours. Elevated to near-critical fire-weather conditions appear likely amid dry fuels across portions of southern CA, particularly overnight D2/Tues into D3/Wed. Some uncertainty remains regarding the strength of the winds and minimum RH values in the absence of stronger upper-level support. The best overlap of strong winds and low RH is expected late D2/Tues into early D3/Wed morning. However, if winds trend stronger and earlier as some guidance suggests, critical highlights may be needed sooner. ..Lyons.. 12/16/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0147 AM CST Mon Dec 16 2024 Valid 161200Z - 171200Z ...NO CRITICAL AREAS... ...Synopsis... Fire-weather concerns across the CONUS are minimal. A cold front trailing a strong low in southern Canada will cross the central US, allowing a much cooler air mass to settle over the western US and Rockies. Despite strong mid-level flow supporting downslope winds, poor overlap of strong winds and low humidity is expected outside of brief gusty offshore winds in southern CA. Otherwise, precipitation ahead of the front and from the prior day will augment fuels such that little or no fire-weather risk is expected. ..Lyons.. 12/16/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0147 AM CST Mon Dec 16 2024 Valid 161200Z - 171200Z ...NO CRITICAL AREAS... ...Synopsis... Fire-weather concerns across the CONUS are minimal. A cold front trailing a strong low in southern Canada will cross the central US, allowing a much cooler air mass to settle over the western US and Rockies. Despite strong mid-level flow supporting downslope winds, poor overlap of strong winds and low humidity is expected outside of brief gusty offshore winds in southern CA. Otherwise, precipitation ahead of the front and from the prior day will augment fuels such that little or no fire-weather risk is expected. ..Lyons.. 12/16/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0147 AM CST Mon Dec 16 2024 Valid 161200Z - 171200Z ...NO CRITICAL AREAS... ...Synopsis... Fire-weather concerns across the CONUS are minimal. A cold front trailing a strong low in southern Canada will cross the central US, allowing a much cooler air mass to settle over the western US and Rockies. Despite strong mid-level flow supporting downslope winds, poor overlap of strong winds and low humidity is expected outside of brief gusty offshore winds in southern CA. Otherwise, precipitation ahead of the front and from the prior day will augment fuels such that little or no fire-weather risk is expected. ..Lyons.. 12/16/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0147 AM CST Mon Dec 16 2024 Valid 161200Z - 171200Z ...NO CRITICAL AREAS... ...Synopsis... Fire-weather concerns across the CONUS are minimal. A cold front trailing a strong low in southern Canada will cross the central US, allowing a much cooler air mass to settle over the western US and Rockies. Despite strong mid-level flow supporting downslope winds, poor overlap of strong winds and low humidity is expected outside of brief gusty offshore winds in southern CA. Otherwise, precipitation ahead of the front and from the prior day will augment fuels such that little or no fire-weather risk is expected. ..Lyons.. 12/16/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0147 AM CST Mon Dec 16 2024 Valid 161200Z - 171200Z ...NO CRITICAL AREAS... ...Synopsis... Fire-weather concerns across the CONUS are minimal. A cold front trailing a strong low in southern Canada will cross the central US, allowing a much cooler air mass to settle over the western US and Rockies. Despite strong mid-level flow supporting downslope winds, poor overlap of strong winds and low humidity is expected outside of brief gusty offshore winds in southern CA. Otherwise, precipitation ahead of the front and from the prior day will augment fuels such that little or no fire-weather risk is expected. ..Lyons.. 12/16/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0147 AM CST Mon Dec 16 2024 Valid 161200Z - 171200Z ...NO CRITICAL AREAS... ...Synopsis... Fire-weather concerns across the CONUS are minimal. A cold front trailing a strong low in southern Canada will cross the central US, allowing a much cooler air mass to settle over the western US and Rockies. Despite strong mid-level flow supporting downslope winds, poor overlap of strong winds and low humidity is expected outside of brief gusty offshore winds in southern CA. Otherwise, precipitation ahead of the front and from the prior day will augment fuels such that little or no fire-weather risk is expected. ..Lyons.. 12/16/2024 ...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 1231 AM CST Mon Dec 16 2024 Valid 171200Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are expected from the southern Plains to the Lower Ohio and Tennessee Valley vicinities and across Florida on Tuesday. Severe-thunderstorm chances are low at this time. ...Eastern OK/ArkLaTex/Ozarks Vicinity... An upper trough will deepen as it moves across the Plains to the MS Valley vicinity on Tuesday. A 500 mb jet max around 50-70 kt will become oriented from eastern OK into the Ohio Valley/lower Great Lakes area after 06z, and stronger height falls are not expected to overspread the region until the nighttime hours. At the surface, 50s to low/mid 60s F dewpoints are expected across south/east TX into the Mid-South vicinity. A strong cold front will track southeast across KS/OK during the evening, and by 06z be positioned from northern AR into southeast OK and north-central TX. This boundary will become a focus for increasing isentropic ascent and isolated to scattered thunderstorms during the overnight/early Wednesday period. Neutral height tendencies will likely suppress convection during the day across much of the area. As convection develops along the advancing cold front overnight, uncertainty remains regarding any surface-based instability overlapping with stronger vertical shear (which decreases rapidly with southward extent). Forecast soundings vary across forecast guidance, but at least weak elevated instability is expected driven by cooling aloft. Stronger elevated cores could produce small hail, given forecast lapse rates around 6.8-7 C/km amid 30+ kt effective shear magnitudes (especially from southeast OK into AR). Overall, severe potential appears quite conditional for the last 3-6 hours of the forecast period. Will hold off on including low-end hail probabilities, though a Marginal (level 1 of 5) risk may be needed in later outlooks depending on forecast trends. ...FL Peninsula... Isolated thunderstorms are expected on Tuesday as a moist airmass and at least weak instability overspread the region. Onshore, easterly low-level flow will provide convergence along an inverted surface trough. Given sufficient destabilization, this will support development of thunderstorms moving onshore through evening. Weak 0-6 km bulk shear (less than 20 kt) will preclude organized convection, and severe storms are not expected. ..Leitman.. 12/16/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 AM CST Mon Dec 16 2024 Valid 171200Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are expected from the southern Plains to the Lower Ohio and Tennessee Valley vicinities and across Florida on Tuesday. Severe-thunderstorm chances are low at this time. ...Eastern OK/ArkLaTex/Ozarks Vicinity... An upper trough will deepen as it moves across the Plains to the MS Valley vicinity on Tuesday. A 500 mb jet max around 50-70 kt will become oriented from eastern OK into the Ohio Valley/lower Great Lakes area after 06z, and stronger height falls are not expected to overspread the region until the nighttime hours. At the surface, 50s to low/mid 60s F dewpoints are expected across south/east TX into the Mid-South vicinity. A strong cold front will track southeast across KS/OK during the evening, and by 06z be positioned from northern AR into southeast OK and north-central TX. This boundary will become a focus for increasing isentropic ascent and isolated to scattered thunderstorms during the overnight/early Wednesday period. Neutral height tendencies will likely suppress convection during the day across much of the area. As convection develops along the advancing cold front overnight, uncertainty remains regarding any surface-based instability overlapping with stronger vertical shear (which decreases rapidly with southward extent). Forecast soundings vary across forecast guidance, but at least weak elevated instability is expected driven by cooling aloft. Stronger elevated cores could produce small hail, given forecast lapse rates around 6.8-7 C/km amid 30+ kt effective shear magnitudes (especially from southeast OK into AR). Overall, severe potential appears quite conditional for the last 3-6 hours of the forecast period. Will hold off on including low-end hail probabilities, though a Marginal (level 1 of 5) risk may be needed in later outlooks depending on forecast trends. ...FL Peninsula... Isolated thunderstorms are expected on Tuesday as a moist airmass and at least weak instability overspread the region. Onshore, easterly low-level flow will provide convergence along an inverted surface trough. Given sufficient destabilization, this will support development of thunderstorms moving onshore through evening. Weak 0-6 km bulk shear (less than 20 kt) will preclude organized convection, and severe storms are not expected. ..Leitman.. 12/16/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 AM CST Mon Dec 16 2024 Valid 171200Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are expected from the southern Plains to the Lower Ohio and Tennessee Valley vicinities and across Florida on Tuesday. Severe-thunderstorm chances are low at this time. ...Eastern OK/ArkLaTex/Ozarks Vicinity... An upper trough will deepen as it moves across the Plains to the MS Valley vicinity on Tuesday. A 500 mb jet max around 50-70 kt will become oriented from eastern OK into the Ohio Valley/lower Great Lakes area after 06z, and stronger height falls are not expected to overspread the region until the nighttime hours. At the surface, 50s to low/mid 60s F dewpoints are expected across south/east TX into the Mid-South vicinity. A strong cold front will track southeast across KS/OK during the evening, and by 06z be positioned from northern AR into southeast OK and north-central TX. This boundary will become a focus for increasing isentropic ascent and isolated to scattered thunderstorms during the overnight/early Wednesday period. Neutral height tendencies will likely suppress convection during the day across much of the area. As convection develops along the advancing cold front overnight, uncertainty remains regarding any surface-based instability overlapping with stronger vertical shear (which decreases rapidly with southward extent). Forecast soundings vary across forecast guidance, but at least weak elevated instability is expected driven by cooling aloft. Stronger elevated cores could produce small hail, given forecast lapse rates around 6.8-7 C/km amid 30+ kt effective shear magnitudes (especially from southeast OK into AR). Overall, severe potential appears quite conditional for the last 3-6 hours of the forecast period. Will hold off on including low-end hail probabilities, though a Marginal (level 1 of 5) risk may be needed in later outlooks depending on forecast trends. ...FL Peninsula... Isolated thunderstorms are expected on Tuesday as a moist airmass and at least weak instability overspread the region. Onshore, easterly low-level flow will provide convergence along an inverted surface trough. Given sufficient destabilization, this will support development of thunderstorms moving onshore through evening. Weak 0-6 km bulk shear (less than 20 kt) will preclude organized convection, and severe storms are not expected. ..Leitman.. 12/16/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 AM CST Mon Dec 16 2024 Valid 171200Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are expected from the southern Plains to the Lower Ohio and Tennessee Valley vicinities and across Florida on Tuesday. Severe-thunderstorm chances are low at this time. ...Eastern OK/ArkLaTex/Ozarks Vicinity... An upper trough will deepen as it moves across the Plains to the MS Valley vicinity on Tuesday. A 500 mb jet max around 50-70 kt will become oriented from eastern OK into the Ohio Valley/lower Great Lakes area after 06z, and stronger height falls are not expected to overspread the region until the nighttime hours. At the surface, 50s to low/mid 60s F dewpoints are expected across south/east TX into the Mid-South vicinity. A strong cold front will track southeast across KS/OK during the evening, and by 06z be positioned from northern AR into southeast OK and north-central TX. This boundary will become a focus for increasing isentropic ascent and isolated to scattered thunderstorms during the overnight/early Wednesday period. Neutral height tendencies will likely suppress convection during the day across much of the area. As convection develops along the advancing cold front overnight, uncertainty remains regarding any surface-based instability overlapping with stronger vertical shear (which decreases rapidly with southward extent). Forecast soundings vary across forecast guidance, but at least weak elevated instability is expected driven by cooling aloft. Stronger elevated cores could produce small hail, given forecast lapse rates around 6.8-7 C/km amid 30+ kt effective shear magnitudes (especially from southeast OK into AR). Overall, severe potential appears quite conditional for the last 3-6 hours of the forecast period. Will hold off on including low-end hail probabilities, though a Marginal (level 1 of 5) risk may be needed in later outlooks depending on forecast trends. ...FL Peninsula... Isolated thunderstorms are expected on Tuesday as a moist airmass and at least weak instability overspread the region. Onshore, easterly low-level flow will provide convergence along an inverted surface trough. Given sufficient destabilization, this will support development of thunderstorms moving onshore through evening. Weak 0-6 km bulk shear (less than 20 kt) will preclude organized convection, and severe storms are not expected. ..Leitman.. 12/16/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1231 AM CST Mon Dec 16 2024 Valid 171200Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Thunderstorms are expected from the southern Plains to the Lower Ohio and Tennessee Valley vicinities and across Florida on Tuesday. Severe-thunderstorm chances are low at this time. ...Eastern OK/ArkLaTex/Ozarks Vicinity... An upper trough will deepen as it moves across the Plains to the MS Valley vicinity on Tuesday. A 500 mb jet max around 50-70 kt will become oriented from eastern OK into the Ohio Valley/lower Great Lakes area after 06z, and stronger height falls are not expected to overspread the region until the nighttime hours. At the surface, 50s to low/mid 60s F dewpoints are expected across south/east TX into the Mid-South vicinity. A strong cold front will track southeast across KS/OK during the evening, and by 06z be positioned from northern AR into southeast OK and north-central TX. This boundary will become a focus for increasing isentropic ascent and isolated to scattered thunderstorms during the overnight/early Wednesday period. Neutral height tendencies will likely suppress convection during the day across much of the area. As convection develops along the advancing cold front overnight, uncertainty remains regarding any surface-based instability overlapping with stronger vertical shear (which decreases rapidly with southward extent). Forecast soundings vary across forecast guidance, but at least weak elevated instability is expected driven by cooling aloft. Stronger elevated cores could produce small hail, given forecast lapse rates around 6.8-7 C/km amid 30+ kt effective shear magnitudes (especially from southeast OK into AR). Overall, severe potential appears quite conditional for the last 3-6 hours of the forecast period. Will hold off on including low-end hail probabilities, though a Marginal (level 1 of 5) risk may be needed in later outlooks depending on forecast trends. ...FL Peninsula... Isolated thunderstorms are expected on Tuesday as a moist airmass and at least weak instability overspread the region. Onshore, easterly low-level flow will provide convergence along an inverted surface trough. Given sufficient destabilization, this will support development of thunderstorms moving onshore through evening. Weak 0-6 km bulk shear (less than 20 kt) will preclude organized convection, and severe storms are not expected. ..Leitman.. 12/16/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1154 PM CST Sun Dec 15 2024 Valid 161200Z - 171200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not expected today or tonight. ...Synopsis... A progressive mid-level trough over the northern Plains is forecast to move eastward and intensify over the Great Lakes tonight. As the upper trough strengths, so too will an attendant surface cyclone moving across southern Canada. As the low moves east, an accompanying cold front will be in place from Ontario to the ArkLaTex. This front will move east southeastward through much of the day before weakening and stalling across northeast TX this evening into early Tuesday. Scattered to numerous thunderstorms are expected from the lower OH Valley to the ArklaTex, with isolated storms possible across western OR and southern FL. ...Ozarks and the ArkLaTex... Along and south of the front, low-level advection of a seasonably moist air mass will support scattered to numerous storms overnight, prior to the Day 1 period across eastern OK and the Ozark Plateau. These storms, a few of which could be stronger, will likely continue through daybreak as residual buoyancy and moderate deep-layer shear slowly weaken. Any strong storm activity should quickly wane as the upper trough departs to the northeast and storms begin to move north of the more buoyant warm sector. Convection should gradually redevelop across northern LA, central/southern AR, into northeast TX later this afternoon into the evening. While muted from lingering cloud cover, forecast soundings show a modest increase in buoyancy as surface temperatures warm to near 70 F amid mid 60s F dewpoints. A stronger storm or two may pose a risk for an occasional strong gust as the front moves slowly southeast. However, decreasing large-scale ascent with mid-level height rises and weakening vertical shear suggest limited potential for storm organization and longevity. This, along with modest low and mid-level lapse rates should keep severe potential below 5%. ..Lyons/Grams.. 12/16/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1154 PM CST Sun Dec 15 2024 Valid 161200Z - 171200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not expected today or tonight. ...Synopsis... A progressive mid-level trough over the northern Plains is forecast to move eastward and intensify over the Great Lakes tonight. As the upper trough strengths, so too will an attendant surface cyclone moving across southern Canada. As the low moves east, an accompanying cold front will be in place from Ontario to the ArkLaTex. This front will move east southeastward through much of the day before weakening and stalling across northeast TX this evening into early Tuesday. Scattered to numerous thunderstorms are expected from the lower OH Valley to the ArklaTex, with isolated storms possible across western OR and southern FL. ...Ozarks and the ArkLaTex... Along and south of the front, low-level advection of a seasonably moist air mass will support scattered to numerous storms overnight, prior to the Day 1 period across eastern OK and the Ozark Plateau. These storms, a few of which could be stronger, will likely continue through daybreak as residual buoyancy and moderate deep-layer shear slowly weaken. Any strong storm activity should quickly wane as the upper trough departs to the northeast and storms begin to move north of the more buoyant warm sector. Convection should gradually redevelop across northern LA, central/southern AR, into northeast TX later this afternoon into the evening. While muted from lingering cloud cover, forecast soundings show a modest increase in buoyancy as surface temperatures warm to near 70 F amid mid 60s F dewpoints. A stronger storm or two may pose a risk for an occasional strong gust as the front moves slowly southeast. However, decreasing large-scale ascent with mid-level height rises and weakening vertical shear suggest limited potential for storm organization and longevity. This, along with modest low and mid-level lapse rates should keep severe potential below 5%. ..Lyons/Grams.. 12/16/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1154 PM CST Sun Dec 15 2024 Valid 161200Z - 171200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not expected today or tonight. ...Synopsis... A progressive mid-level trough over the northern Plains is forecast to move eastward and intensify over the Great Lakes tonight. As the upper trough strengths, so too will an attendant surface cyclone moving across southern Canada. As the low moves east, an accompanying cold front will be in place from Ontario to the ArkLaTex. This front will move east southeastward through much of the day before weakening and stalling across northeast TX this evening into early Tuesday. Scattered to numerous thunderstorms are expected from the lower OH Valley to the ArklaTex, with isolated storms possible across western OR and southern FL. ...Ozarks and the ArkLaTex... Along and south of the front, low-level advection of a seasonably moist air mass will support scattered to numerous storms overnight, prior to the Day 1 period across eastern OK and the Ozark Plateau. These storms, a few of which could be stronger, will likely continue through daybreak as residual buoyancy and moderate deep-layer shear slowly weaken. Any strong storm activity should quickly wane as the upper trough departs to the northeast and storms begin to move north of the more buoyant warm sector. Convection should gradually redevelop across northern LA, central/southern AR, into northeast TX later this afternoon into the evening. While muted from lingering cloud cover, forecast soundings show a modest increase in buoyancy as surface temperatures warm to near 70 F amid mid 60s F dewpoints. A stronger storm or two may pose a risk for an occasional strong gust as the front moves slowly southeast. However, decreasing large-scale ascent with mid-level height rises and weakening vertical shear suggest limited potential for storm organization and longevity. This, along with modest low and mid-level lapse rates should keep severe potential below 5%. ..Lyons/Grams.. 12/16/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1154 PM CST Sun Dec 15 2024 Valid 161200Z - 171200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not expected today or tonight. ...Synopsis... A progressive mid-level trough over the northern Plains is forecast to move eastward and intensify over the Great Lakes tonight. As the upper trough strengths, so too will an attendant surface cyclone moving across southern Canada. As the low moves east, an accompanying cold front will be in place from Ontario to the ArkLaTex. This front will move east southeastward through much of the day before weakening and stalling across northeast TX this evening into early Tuesday. Scattered to numerous thunderstorms are expected from the lower OH Valley to the ArklaTex, with isolated storms possible across western OR and southern FL. ...Ozarks and the ArkLaTex... Along and south of the front, low-level advection of a seasonably moist air mass will support scattered to numerous storms overnight, prior to the Day 1 period across eastern OK and the Ozark Plateau. These storms, a few of which could be stronger, will likely continue through daybreak as residual buoyancy and moderate deep-layer shear slowly weaken. Any strong storm activity should quickly wane as the upper trough departs to the northeast and storms begin to move north of the more buoyant warm sector. Convection should gradually redevelop across northern LA, central/southern AR, into northeast TX later this afternoon into the evening. While muted from lingering cloud cover, forecast soundings show a modest increase in buoyancy as surface temperatures warm to near 70 F amid mid 60s F dewpoints. A stronger storm or two may pose a risk for an occasional strong gust as the front moves slowly southeast. However, decreasing large-scale ascent with mid-level height rises and weakening vertical shear suggest limited potential for storm organization and longevity. This, along with modest low and mid-level lapse rates should keep severe potential below 5%. ..Lyons/Grams.. 12/16/2024 Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1154 PM CST Sun Dec 15 2024 Valid 161200Z - 171200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe storms are not expected today or tonight. ...Synopsis... A progressive mid-level trough over the northern Plains is forecast to move eastward and intensify over the Great Lakes tonight. As the upper trough strengths, so too will an attendant surface cyclone moving across southern Canada. As the low moves east, an accompanying cold front will be in place from Ontario to the ArkLaTex. This front will move east southeastward through much of the day before weakening and stalling across northeast TX this evening into early Tuesday. Scattered to numerous thunderstorms are expected from the lower OH Valley to the ArklaTex, with isolated storms possible across western OR and southern FL. ...Ozarks and the ArkLaTex... Along and south of the front, low-level advection of a seasonably moist air mass will support scattered to numerous storms overnight, prior to the Day 1 period across eastern OK and the Ozark Plateau. These storms, a few of which could be stronger, will likely continue through daybreak as residual buoyancy and moderate deep-layer shear slowly weaken. Any strong storm activity should quickly wane as the upper trough departs to the northeast and storms begin to move north of the more buoyant warm sector. Convection should gradually redevelop across northern LA, central/southern AR, into northeast TX later this afternoon into the evening. While muted from lingering cloud cover, forecast soundings show a modest increase in buoyancy as surface temperatures warm to near 70 F amid mid 60s F dewpoints. A stronger storm or two may pose a risk for an occasional strong gust as the front moves slowly southeast. However, decreasing large-scale ascent with mid-level height rises and weakening vertical shear suggest limited potential for storm organization and longevity. This, along with modest low and mid-level lapse rates should keep severe potential below 5%. ..Lyons/Grams.. 12/16/2024 Read more

MD 2269 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF NORTHEASTERN OKLAHOMA...NORTHWESTERN ARKANSAS...SOUTHERN MISSOURI
Mesoscale Discussion 2269 NWS Storm Prediction Center Norman OK 1001 PM CST Sun Dec 15 2024 Areas affected...parts of northeastern Oklahoma...northwestern Arkansas...southern Missouri Concerning...Severe potential...Watch unlikely Valid 160401Z - 160630Z Probability of Watch Issuance...5 percent SUMMARY...A substantive increase in thunderstorm development appears likely across the Ozarks Plateau vicinity into adjacent lower Ohio Valley during the Midnight-3 AM CST time frame. Initially this may include widely scattered strong storms posing a risk for marginally severe hail, particularly across parts of northeastern Oklahoma into southwestern Missouri and adjacent northwestern Arkansas. DISCUSSION...Seasonably moist low-level return flow is in the process of veering from a southwesterly to more of a westerly component in the 925-850 mb layer across eastern Oklahoma through southern Missouri. However, as moisture quality continues to increase during the next few hours, this is still forecast to lead to substantive destabilization, as mid-level heights gradually begin to fall across the southern Great Plains through Ozark Plateau vicinity. Large-scale ascent and cooling aloft appear likely to weaken inhibition sufficiently to support increasing thunderstorm development in a corridor as far east as southern Illinois and adjacent portions of the lower Ohio Valley by 08-09Z. Based on forecast soundings, destabilization across much of this swath will remain rooted above a generally cool and stable boundary layer. However, modestly steep mid-level lapse rates might contribute to sufficient conditional and convective instability to support small to marginally severe hail in widely scattered stronger initial cells, before convection becomes more widespread. Storms capable of producing severe hail may be most concentrated (in a relative sense) across northeastern Oklahoma into southwestern Missouri and adjacent northwestern Arkansas, where surface dew points are increasing to around 60F. Although destabilization may become rooted close to the surface across this area (in close proximity to the surface troughing), guidance suggests that this may coincide with low-level hodographs shrinking and trending more linear. ..Kerr/Smith.. 12/16/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...LZK...SGF...TSA... LAT...LON 36909531 37979203 36299139 35469436 35769607 36909531 Read more