Severe Storms

No Mesoscale Discussions are in effect as of Thu Nov 30 21:30:02 UTC 2023.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0248 PM CST Thu Nov 30 2023 Valid 021200Z - 081200Z Multiple mid-level troughs will traverse the CONUS east of the Rockies through mid next week, before an upper ridge overspreads the central U.S. During the weekend through early next week, surface lee troughing/cyclone development will encourage dry downslope flow across the southern High Plains each day, with near critical surface winds/RH possible on Day 3/Saturday. However, appreciable rainfall is ongoing across the southern High Plains, casting doubt on the receptiveness of fuels to support significant wildfire spread potential. Critical highlights have been withheld this outlook. Still, an instance or two of more locally Elevated conditions cannot be ruled out over the southern High Plains this weekend into early next week where RH less than 20 percent, strong wind gusts, and drier fuel beds can all overlap. ..Squitieri.. 11/30/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0248 PM CST Thu Nov 30 2023 Valid 021200Z - 081200Z Multiple mid-level troughs will traverse the CONUS east of the Rockies through mid next week, before an upper ridge overspreads the central U.S. During the weekend through early next week, surface lee troughing/cyclone development will encourage dry downslope flow across the southern High Plains each day, with near critical surface winds/RH possible on Day 3/Saturday. However, appreciable rainfall is ongoing across the southern High Plains, casting doubt on the receptiveness of fuels to support significant wildfire spread potential. Critical highlights have been withheld this outlook. Still, an instance or two of more locally Elevated conditions cannot be ruled out over the southern High Plains this weekend into early next week where RH less than 20 percent, strong wind gusts, and drier fuel beds can all overlap. ..Squitieri.. 11/30/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0248 PM CST Thu Nov 30 2023 Valid 021200Z - 081200Z Multiple mid-level troughs will traverse the CONUS east of the Rockies through mid next week, before an upper ridge overspreads the central U.S. During the weekend through early next week, surface lee troughing/cyclone development will encourage dry downslope flow across the southern High Plains each day, with near critical surface winds/RH possible on Day 3/Saturday. However, appreciable rainfall is ongoing across the southern High Plains, casting doubt on the receptiveness of fuels to support significant wildfire spread potential. Critical highlights have been withheld this outlook. Still, an instance or two of more locally Elevated conditions cannot be ruled out over the southern High Plains this weekend into early next week where RH less than 20 percent, strong wind gusts, and drier fuel beds can all overlap. ..Squitieri.. 11/30/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0248 PM CST Thu Nov 30 2023 Valid 021200Z - 081200Z Multiple mid-level troughs will traverse the CONUS east of the Rockies through mid next week, before an upper ridge overspreads the central U.S. During the weekend through early next week, surface lee troughing/cyclone development will encourage dry downslope flow across the southern High Plains each day, with near critical surface winds/RH possible on Day 3/Saturday. However, appreciable rainfall is ongoing across the southern High Plains, casting doubt on the receptiveness of fuels to support significant wildfire spread potential. Critical highlights have been withheld this outlook. Still, an instance or two of more locally Elevated conditions cannot be ruled out over the southern High Plains this weekend into early next week where RH less than 20 percent, strong wind gusts, and drier fuel beds can all overlap. ..Squitieri.. 11/30/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0248 PM CST Thu Nov 30 2023 Valid 021200Z - 081200Z Multiple mid-level troughs will traverse the CONUS east of the Rockies through mid next week, before an upper ridge overspreads the central U.S. During the weekend through early next week, surface lee troughing/cyclone development will encourage dry downslope flow across the southern High Plains each day, with near critical surface winds/RH possible on Day 3/Saturday. However, appreciable rainfall is ongoing across the southern High Plains, casting doubt on the receptiveness of fuels to support significant wildfire spread potential. Critical highlights have been withheld this outlook. Still, an instance or two of more locally Elevated conditions cannot be ruled out over the southern High Plains this weekend into early next week where RH less than 20 percent, strong wind gusts, and drier fuel beds can all overlap. ..Squitieri.. 11/30/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0248 PM CST Thu Nov 30 2023 Valid 021200Z - 081200Z Multiple mid-level troughs will traverse the CONUS east of the Rockies through mid next week, before an upper ridge overspreads the central U.S. During the weekend through early next week, surface lee troughing/cyclone development will encourage dry downslope flow across the southern High Plains each day, with near critical surface winds/RH possible on Day 3/Saturday. However, appreciable rainfall is ongoing across the southern High Plains, casting doubt on the receptiveness of fuels to support significant wildfire spread potential. Critical highlights have been withheld this outlook. Still, an instance or two of more locally Elevated conditions cannot be ruled out over the southern High Plains this weekend into early next week where RH less than 20 percent, strong wind gusts, and drier fuel beds can all overlap. ..Squitieri.. 11/30/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0248 PM CST Thu Nov 30 2023 Valid 021200Z - 081200Z Multiple mid-level troughs will traverse the CONUS east of the Rockies through mid next week, before an upper ridge overspreads the central U.S. During the weekend through early next week, surface lee troughing/cyclone development will encourage dry downslope flow across the southern High Plains each day, with near critical surface winds/RH possible on Day 3/Saturday. However, appreciable rainfall is ongoing across the southern High Plains, casting doubt on the receptiveness of fuels to support significant wildfire spread potential. Critical highlights have been withheld this outlook. Still, an instance or two of more locally Elevated conditions cannot be ruled out over the southern High Plains this weekend into early next week where RH less than 20 percent, strong wind gusts, and drier fuel beds can all overlap. ..Squitieri.. 11/30/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0248 PM CST Thu Nov 30 2023 Valid 021200Z - 081200Z Multiple mid-level troughs will traverse the CONUS east of the Rockies through mid next week, before an upper ridge overspreads the central U.S. During the weekend through early next week, surface lee troughing/cyclone development will encourage dry downslope flow across the southern High Plains each day, with near critical surface winds/RH possible on Day 3/Saturday. However, appreciable rainfall is ongoing across the southern High Plains, casting doubt on the receptiveness of fuels to support significant wildfire spread potential. Critical highlights have been withheld this outlook. Still, an instance or two of more locally Elevated conditions cannot be ruled out over the southern High Plains this weekend into early next week where RH less than 20 percent, strong wind gusts, and drier fuel beds can all overlap. ..Squitieri.. 11/30/2023 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 2291 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR NORTHEAST TEXAS INTO FAR SOUTHEASTERN OKLAHOMA
Mesoscale Discussion 2291 NWS Storm Prediction Center Norman OK 1244 PM CST Thu Nov 30 2023 Areas affected...Northeast Texas into far southwestern Oklahoma Concerning...Severe potential...Watch unlikely Valid 301844Z - 302045Z Probability of Watch Issuance...5 percent SUMMARY...The potential for isolated severe hail, and perhaps damaging wind gusts, should increase through the mid-afternoon hours across northeast Texas and portions of far southwestern Oklahoma. Watch issuance is not expected. DISCUSSION...Over the past hour, the coverage and intensity of convection has increased across central to northeast TX as lift within a warm advection regime and ahead of an approaching upper wave increases. While much of this convection is well displaced from a narrow plume of surface-based buoyancy stretching from the TX Gulf coast into central TX, MUCAPE across northeast TX has steadily increased to around 1000 J/kg amid warming/moistening within the 925-850 mb layer. Observed storm motions and a lack of apparent low-level mesocyclones further suggest that this convection is rooted above the surface, but elongated hodographs above 2 km (featuring effective bulk shear values near 40 knots), should support storm organization with an attendant risk of isolated large hail. Cooling cloud top temperatures and an uptick in lightning counts over the past 15-30 minutes suggest convection is beginning to realize this environment, so an increasing hail threat seems probable (though clustered storm modes may inhibit the overall threat). Recent hi-res guidance, including HRRR-based SCRAMM solutions and WOFS ensemble output, appears to have picked up on this trend and shows increasing potential for isolated hail across northeast TX over the next several hours. While the signal for severe winds is comparatively weaker, a few damaging gusts will be possible. Regardless, the overall severe threat should remain too limited to warrant watch issuance. ..Moore/Thompson.. 11/30/2023 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...SHV...TSA...HGX...FWD...OUN... LAT...LON 31409742 31779765 32809746 33529748 33949761 34369566 34179495 33879449 33059425 32399443 31749489 31529539 31409742 Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Thu Nov 30 2023 Valid 302000Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA... ...SUMMARY... A few severe storms/tornadoes are possible through tonight from southeast Texas into southern Louisiana. Farther north, isolated hail and strong wind gusts will also be possible across parts of East/North Texas and southern Oklahoma. ...20z Update... The only changes with the 20z update were to trim the western edges of the outlook area based on latest observation trends and location of current convection. Widespread cloud cover and scattered convection has limited heating, and combined with poor low-level lapse rates, low-level inhibition is limited surface-based storm development. Some stronger storms may still develop this evening near the Sabine River as the surface cold front tracks southeast. However, overall severe potential will likely remain somewhat subdued due to poor thermodynamics despite favorable vertical shear. ..Leitman.. 11/30/2023 .PREV DISCUSSION... /ISSUED 1025 AM CST Thu Nov 30 2023/ ...Northwest Gulf coast and southern Plains through tonight... Thunderstorms are forming this morning over southeast TX from Matagorda Bay northeastward through the Houston area to Toledo Bend reservoir. The convection appears to be driven by low-level warm advection, as well as a subtle/lead speed max ejecting aloft, in advance of the primary shortwave trough over NM. Observed and forecast hodographs (with substantial length and curvature) across southeast TX look favorable for right-moving supercells with some tornado potential. However, with widespread cloud cover and warm advection being the primary mode of storm initiation, the updrafts may be rooted slightly above the ground. Thus, the convection may not take full advantage of the shear profiles, compared to a more favorable scenario where fully surface-based storms formed in a warmer environment upstream and moved into the environment expected across southeast TX/upper TX coast this afternoon/evening. Regardless, there will be some potential for supercells and a few tornadoes given the strong low-level shear in a moistening/gradually destabilizing environment, with the aforementioned caveats related to poor low-level lapse rates. This threat will slowly increase across southeast TX/upper TX coast through the afternoon and continue through tonight while spreading eastward into southwest/south central LA. Farther northwest, elevated thunderstorm development is expected from central/north TX into southern OK, in the zone of ascent preceding the primary shortwave trough that will begin to move east-northeastward this afternoon from NM toward OK and north TX. The strongest of these storms will pose some threat for marginally severe hail based on some steepening of midlevel lapse rates and relatively long hodographs aloft. A narrow zone of buoyancy rooted near the surface may develop later this afternoon from western north TX into extreme southwest OK, near the primary surface cyclone. However, the main forcing for ascent will be east/northeast of this zone by late afternoon, and forecast hodographs reflect low-midlevel wave passage with a pronounced veer-back signature relatively close to the ground (as low as 1 km AGL). Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Thu Nov 30 2023 Valid 302000Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA... ...SUMMARY... A few severe storms/tornadoes are possible through tonight from southeast Texas into southern Louisiana. Farther north, isolated hail and strong wind gusts will also be possible across parts of East/North Texas and southern Oklahoma. ...20z Update... The only changes with the 20z update were to trim the western edges of the outlook area based on latest observation trends and location of current convection. Widespread cloud cover and scattered convection has limited heating, and combined with poor low-level lapse rates, low-level inhibition is limited surface-based storm development. Some stronger storms may still develop this evening near the Sabine River as the surface cold front tracks southeast. However, overall severe potential will likely remain somewhat subdued due to poor thermodynamics despite favorable vertical shear. ..Leitman.. 11/30/2023 .PREV DISCUSSION... /ISSUED 1025 AM CST Thu Nov 30 2023/ ...Northwest Gulf coast and southern Plains through tonight... Thunderstorms are forming this morning over southeast TX from Matagorda Bay northeastward through the Houston area to Toledo Bend reservoir. The convection appears to be driven by low-level warm advection, as well as a subtle/lead speed max ejecting aloft, in advance of the primary shortwave trough over NM. Observed and forecast hodographs (with substantial length and curvature) across southeast TX look favorable for right-moving supercells with some tornado potential. However, with widespread cloud cover and warm advection being the primary mode of storm initiation, the updrafts may be rooted slightly above the ground. Thus, the convection may not take full advantage of the shear profiles, compared to a more favorable scenario where fully surface-based storms formed in a warmer environment upstream and moved into the environment expected across southeast TX/upper TX coast this afternoon/evening. Regardless, there will be some potential for supercells and a few tornadoes given the strong low-level shear in a moistening/gradually destabilizing environment, with the aforementioned caveats related to poor low-level lapse rates. This threat will slowly increase across southeast TX/upper TX coast through the afternoon and continue through tonight while spreading eastward into southwest/south central LA. Farther northwest, elevated thunderstorm development is expected from central/north TX into southern OK, in the zone of ascent preceding the primary shortwave trough that will begin to move east-northeastward this afternoon from NM toward OK and north TX. The strongest of these storms will pose some threat for marginally severe hail based on some steepening of midlevel lapse rates and relatively long hodographs aloft. A narrow zone of buoyancy rooted near the surface may develop later this afternoon from western north TX into extreme southwest OK, near the primary surface cyclone. However, the main forcing for ascent will be east/northeast of this zone by late afternoon, and forecast hodographs reflect low-midlevel wave passage with a pronounced veer-back signature relatively close to the ground (as low as 1 km AGL). Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Thu Nov 30 2023 Valid 302000Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA... ...SUMMARY... A few severe storms/tornadoes are possible through tonight from southeast Texas into southern Louisiana. Farther north, isolated hail and strong wind gusts will also be possible across parts of East/North Texas and southern Oklahoma. ...20z Update... The only changes with the 20z update were to trim the western edges of the outlook area based on latest observation trends and location of current convection. Widespread cloud cover and scattered convection has limited heating, and combined with poor low-level lapse rates, low-level inhibition is limited surface-based storm development. Some stronger storms may still develop this evening near the Sabine River as the surface cold front tracks southeast. However, overall severe potential will likely remain somewhat subdued due to poor thermodynamics despite favorable vertical shear. ..Leitman.. 11/30/2023 .PREV DISCUSSION... /ISSUED 1025 AM CST Thu Nov 30 2023/ ...Northwest Gulf coast and southern Plains through tonight... Thunderstorms are forming this morning over southeast TX from Matagorda Bay northeastward through the Houston area to Toledo Bend reservoir. The convection appears to be driven by low-level warm advection, as well as a subtle/lead speed max ejecting aloft, in advance of the primary shortwave trough over NM. Observed and forecast hodographs (with substantial length and curvature) across southeast TX look favorable for right-moving supercells with some tornado potential. However, with widespread cloud cover and warm advection being the primary mode of storm initiation, the updrafts may be rooted slightly above the ground. Thus, the convection may not take full advantage of the shear profiles, compared to a more favorable scenario where fully surface-based storms formed in a warmer environment upstream and moved into the environment expected across southeast TX/upper TX coast this afternoon/evening. Regardless, there will be some potential for supercells and a few tornadoes given the strong low-level shear in a moistening/gradually destabilizing environment, with the aforementioned caveats related to poor low-level lapse rates. This threat will slowly increase across southeast TX/upper TX coast through the afternoon and continue through tonight while spreading eastward into southwest/south central LA. Farther northwest, elevated thunderstorm development is expected from central/north TX into southern OK, in the zone of ascent preceding the primary shortwave trough that will begin to move east-northeastward this afternoon from NM toward OK and north TX. The strongest of these storms will pose some threat for marginally severe hail based on some steepening of midlevel lapse rates and relatively long hodographs aloft. A narrow zone of buoyancy rooted near the surface may develop later this afternoon from western north TX into extreme southwest OK, near the primary surface cyclone. However, the main forcing for ascent will be east/northeast of this zone by late afternoon, and forecast hodographs reflect low-midlevel wave passage with a pronounced veer-back signature relatively close to the ground (as low as 1 km AGL). Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Thu Nov 30 2023 Valid 302000Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA... ...SUMMARY... A few severe storms/tornadoes are possible through tonight from southeast Texas into southern Louisiana. Farther north, isolated hail and strong wind gusts will also be possible across parts of East/North Texas and southern Oklahoma. ...20z Update... The only changes with the 20z update were to trim the western edges of the outlook area based on latest observation trends and location of current convection. Widespread cloud cover and scattered convection has limited heating, and combined with poor low-level lapse rates, low-level inhibition is limited surface-based storm development. Some stronger storms may still develop this evening near the Sabine River as the surface cold front tracks southeast. However, overall severe potential will likely remain somewhat subdued due to poor thermodynamics despite favorable vertical shear. ..Leitman.. 11/30/2023 .PREV DISCUSSION... /ISSUED 1025 AM CST Thu Nov 30 2023/ ...Northwest Gulf coast and southern Plains through tonight... Thunderstorms are forming this morning over southeast TX from Matagorda Bay northeastward through the Houston area to Toledo Bend reservoir. The convection appears to be driven by low-level warm advection, as well as a subtle/lead speed max ejecting aloft, in advance of the primary shortwave trough over NM. Observed and forecast hodographs (with substantial length and curvature) across southeast TX look favorable for right-moving supercells with some tornado potential. However, with widespread cloud cover and warm advection being the primary mode of storm initiation, the updrafts may be rooted slightly above the ground. Thus, the convection may not take full advantage of the shear profiles, compared to a more favorable scenario where fully surface-based storms formed in a warmer environment upstream and moved into the environment expected across southeast TX/upper TX coast this afternoon/evening. Regardless, there will be some potential for supercells and a few tornadoes given the strong low-level shear in a moistening/gradually destabilizing environment, with the aforementioned caveats related to poor low-level lapse rates. This threat will slowly increase across southeast TX/upper TX coast through the afternoon and continue through tonight while spreading eastward into southwest/south central LA. Farther northwest, elevated thunderstorm development is expected from central/north TX into southern OK, in the zone of ascent preceding the primary shortwave trough that will begin to move east-northeastward this afternoon from NM toward OK and north TX. The strongest of these storms will pose some threat for marginally severe hail based on some steepening of midlevel lapse rates and relatively long hodographs aloft. A narrow zone of buoyancy rooted near the surface may develop later this afternoon from western north TX into extreme southwest OK, near the primary surface cyclone. However, the main forcing for ascent will be east/northeast of this zone by late afternoon, and forecast hodographs reflect low-midlevel wave passage with a pronounced veer-back signature relatively close to the ground (as low as 1 km AGL). Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Thu Nov 30 2023 Valid 302000Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA... ...SUMMARY... A few severe storms/tornadoes are possible through tonight from southeast Texas into southern Louisiana. Farther north, isolated hail and strong wind gusts will also be possible across parts of East/North Texas and southern Oklahoma. ...20z Update... The only changes with the 20z update were to trim the western edges of the outlook area based on latest observation trends and location of current convection. Widespread cloud cover and scattered convection has limited heating, and combined with poor low-level lapse rates, low-level inhibition is limited surface-based storm development. Some stronger storms may still develop this evening near the Sabine River as the surface cold front tracks southeast. However, overall severe potential will likely remain somewhat subdued due to poor thermodynamics despite favorable vertical shear. ..Leitman.. 11/30/2023 .PREV DISCUSSION... /ISSUED 1025 AM CST Thu Nov 30 2023/ ...Northwest Gulf coast and southern Plains through tonight... Thunderstorms are forming this morning over southeast TX from Matagorda Bay northeastward through the Houston area to Toledo Bend reservoir. The convection appears to be driven by low-level warm advection, as well as a subtle/lead speed max ejecting aloft, in advance of the primary shortwave trough over NM. Observed and forecast hodographs (with substantial length and curvature) across southeast TX look favorable for right-moving supercells with some tornado potential. However, with widespread cloud cover and warm advection being the primary mode of storm initiation, the updrafts may be rooted slightly above the ground. Thus, the convection may not take full advantage of the shear profiles, compared to a more favorable scenario where fully surface-based storms formed in a warmer environment upstream and moved into the environment expected across southeast TX/upper TX coast this afternoon/evening. Regardless, there will be some potential for supercells and a few tornadoes given the strong low-level shear in a moistening/gradually destabilizing environment, with the aforementioned caveats related to poor low-level lapse rates. This threat will slowly increase across southeast TX/upper TX coast through the afternoon and continue through tonight while spreading eastward into southwest/south central LA. Farther northwest, elevated thunderstorm development is expected from central/north TX into southern OK, in the zone of ascent preceding the primary shortwave trough that will begin to move east-northeastward this afternoon from NM toward OK and north TX. The strongest of these storms will pose some threat for marginally severe hail based on some steepening of midlevel lapse rates and relatively long hodographs aloft. A narrow zone of buoyancy rooted near the surface may develop later this afternoon from western north TX into extreme southwest OK, near the primary surface cyclone. However, the main forcing for ascent will be east/northeast of this zone by late afternoon, and forecast hodographs reflect low-midlevel wave passage with a pronounced veer-back signature relatively close to the ground (as low as 1 km AGL). Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Thu Nov 30 2023 Valid 302000Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA... ...SUMMARY... A few severe storms/tornadoes are possible through tonight from southeast Texas into southern Louisiana. Farther north, isolated hail and strong wind gusts will also be possible across parts of East/North Texas and southern Oklahoma. ...20z Update... The only changes with the 20z update were to trim the western edges of the outlook area based on latest observation trends and location of current convection. Widespread cloud cover and scattered convection has limited heating, and combined with poor low-level lapse rates, low-level inhibition is limited surface-based storm development. Some stronger storms may still develop this evening near the Sabine River as the surface cold front tracks southeast. However, overall severe potential will likely remain somewhat subdued due to poor thermodynamics despite favorable vertical shear. ..Leitman.. 11/30/2023 .PREV DISCUSSION... /ISSUED 1025 AM CST Thu Nov 30 2023/ ...Northwest Gulf coast and southern Plains through tonight... Thunderstorms are forming this morning over southeast TX from Matagorda Bay northeastward through the Houston area to Toledo Bend reservoir. The convection appears to be driven by low-level warm advection, as well as a subtle/lead speed max ejecting aloft, in advance of the primary shortwave trough over NM. Observed and forecast hodographs (with substantial length and curvature) across southeast TX look favorable for right-moving supercells with some tornado potential. However, with widespread cloud cover and warm advection being the primary mode of storm initiation, the updrafts may be rooted slightly above the ground. Thus, the convection may not take full advantage of the shear profiles, compared to a more favorable scenario where fully surface-based storms formed in a warmer environment upstream and moved into the environment expected across southeast TX/upper TX coast this afternoon/evening. Regardless, there will be some potential for supercells and a few tornadoes given the strong low-level shear in a moistening/gradually destabilizing environment, with the aforementioned caveats related to poor low-level lapse rates. This threat will slowly increase across southeast TX/upper TX coast through the afternoon and continue through tonight while spreading eastward into southwest/south central LA. Farther northwest, elevated thunderstorm development is expected from central/north TX into southern OK, in the zone of ascent preceding the primary shortwave trough that will begin to move east-northeastward this afternoon from NM toward OK and north TX. The strongest of these storms will pose some threat for marginally severe hail based on some steepening of midlevel lapse rates and relatively long hodographs aloft. A narrow zone of buoyancy rooted near the surface may develop later this afternoon from western north TX into extreme southwest OK, near the primary surface cyclone. However, the main forcing for ascent will be east/northeast of this zone by late afternoon, and forecast hodographs reflect low-midlevel wave passage with a pronounced veer-back signature relatively close to the ground (as low as 1 km AGL). Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0154 PM CST Thu Nov 30 2023 Valid 302000Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHEAST TEXAS AND SOUTHWEST LOUISIANA... ...SUMMARY... A few severe storms/tornadoes are possible through tonight from southeast Texas into southern Louisiana. Farther north, isolated hail and strong wind gusts will also be possible across parts of East/North Texas and southern Oklahoma. ...20z Update... The only changes with the 20z update were to trim the western edges of the outlook area based on latest observation trends and location of current convection. Widespread cloud cover and scattered convection has limited heating, and combined with poor low-level lapse rates, low-level inhibition is limited surface-based storm development. Some stronger storms may still develop this evening near the Sabine River as the surface cold front tracks southeast. However, overall severe potential will likely remain somewhat subdued due to poor thermodynamics despite favorable vertical shear. ..Leitman.. 11/30/2023 .PREV DISCUSSION... /ISSUED 1025 AM CST Thu Nov 30 2023/ ...Northwest Gulf coast and southern Plains through tonight... Thunderstorms are forming this morning over southeast TX from Matagorda Bay northeastward through the Houston area to Toledo Bend reservoir. The convection appears to be driven by low-level warm advection, as well as a subtle/lead speed max ejecting aloft, in advance of the primary shortwave trough over NM. Observed and forecast hodographs (with substantial length and curvature) across southeast TX look favorable for right-moving supercells with some tornado potential. However, with widespread cloud cover and warm advection being the primary mode of storm initiation, the updrafts may be rooted slightly above the ground. Thus, the convection may not take full advantage of the shear profiles, compared to a more favorable scenario where fully surface-based storms formed in a warmer environment upstream and moved into the environment expected across southeast TX/upper TX coast this afternoon/evening. Regardless, there will be some potential for supercells and a few tornadoes given the strong low-level shear in a moistening/gradually destabilizing environment, with the aforementioned caveats related to poor low-level lapse rates. This threat will slowly increase across southeast TX/upper TX coast through the afternoon and continue through tonight while spreading eastward into southwest/south central LA. Farther northwest, elevated thunderstorm development is expected from central/north TX into southern OK, in the zone of ascent preceding the primary shortwave trough that will begin to move east-northeastward this afternoon from NM toward OK and north TX. The strongest of these storms will pose some threat for marginally severe hail based on some steepening of midlevel lapse rates and relatively long hodographs aloft. A narrow zone of buoyancy rooted near the surface may develop later this afternoon from western north TX into extreme southwest OK, near the primary surface cyclone. However, the main forcing for ascent will be east/northeast of this zone by late afternoon, and forecast hodographs reflect low-midlevel wave passage with a pronounced veer-back signature relatively close to the ground (as low as 1 km AGL). Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0155 PM CST Thu Nov 30 2023 Valid 011200Z - 021200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 11/30/2023 .PREV DISCUSSION... /ISSUED 1254 AM CST Thu Nov 30 2023/ ...Synopsis... A belt of strong west-southwesterly flow aloft will persist across the southern Rockies, favoring continued breezy downslope flow over the southern High Plains. Similar to Day 1/Thursday, marginal RH (25-30 percent) should mitigate most fire-weather concerns here. Farther west, surface high pressure will build into the Great Basin, yielding an offshore pressure gradient over southern CA. While breezy/gusty north-northeasterly surface winds may support locally elevated fire-weather conditions (primarily over parts of Santa Barbara, Ventura, and Los Angeles Counties), fairly cool surface temperatures will limit RH reductions and the overall fire-weather risk. ...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 0155 PM CST Thu Nov 30 2023 Valid 011200Z - 021200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 11/30/2023 .PREV DISCUSSION... /ISSUED 1254 AM CST Thu Nov 30 2023/ ...Synopsis... A belt of strong west-southwesterly flow aloft will persist across the southern Rockies, favoring continued breezy downslope flow over the southern High Plains. Similar to Day 1/Thursday, marginal RH (25-30 percent) should mitigate most fire-weather concerns here. Farther west, surface high pressure will build into the Great Basin, yielding an offshore pressure gradient over southern CA. While breezy/gusty north-northeasterly surface winds may support locally elevated fire-weather conditions (primarily over parts of Santa Barbara, Ventura, and Los Angeles Counties), fairly cool surface temperatures will limit RH reductions and the overall fire-weather risk. ...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 0155 PM CST Thu Nov 30 2023 Valid 011200Z - 021200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track, with no changes or additions made. ..Squitieri.. 11/30/2023 .PREV DISCUSSION... /ISSUED 1254 AM CST Thu Nov 30 2023/ ...Synopsis... A belt of strong west-southwesterly flow aloft will persist across the southern Rockies, favoring continued breezy downslope flow over the southern High Plains. Similar to Day 1/Thursday, marginal RH (25-30 percent) should mitigate most fire-weather concerns here. Farther west, surface high pressure will build into the Great Basin, yielding an offshore pressure gradient over southern CA. While breezy/gusty north-northeasterly surface winds may support locally elevated fire-weather conditions (primarily over parts of Santa Barbara, Ventura, and Los Angeles Counties), fairly cool surface temperatures will limit RH reductions and the overall fire-weather risk. ...Please see www.spc.noaa.gov/fire for graphic product... Read more