SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0636 PM CST Sun Nov 17 2024 Valid 180100Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTHWEST TEXAS INTO SOUTHWEST OKLAHOMA... ...SUMMARY... Scattered severe thunderstorms are expected to develop across parts of west/northwest Texas into southwest Oklahoma this evening and continuing through daybreak on Monday, posing a risk for severe gusts and a few tornadoes. ...01z Update - TX/OK... No changes have been made to severe probabilities/categories with the 01z update. Thunderstorms will increase in coverage and intensity over the next several hours across west TX, with the severe risk increasing in the 03z-06z time period when the low-level jet begins to markedly increase. This activity is expected to quickly develop into a line/QLCS and spread east/northeast across parts of central and western north TX into southwest OK tonight into early Monday morning. Severe gusts and a few tornadoes remain possible across the broader level 1 to 3 risk area. A corridor of Enhanced risk (level 3 of 5) is expected across portions of western north TX into southwest OK closer to the deepening surface low, particularly in the 8z-12z time frame. Scattered severe gusts, some near 75 mph, and a few tornadoes are possible in this area. Uncertainty remains regarding the northward extent of greater severe potential. Surface-based instability may creep into central OK near the end of the period around 11z-12z, or perhaps just after. Regardless, strong wind field near/just above the surface may still pose a damaging wind risk, and perhaps a tornado, with early morning storms. ..Leitman.. 11/18/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0636 PM CST Sun Nov 17 2024 Valid 180100Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS NORTHWEST TEXAS INTO SOUTHWEST OKLAHOMA... ...SUMMARY... Scattered severe thunderstorms are expected to develop across parts of west/northwest Texas into southwest Oklahoma this evening and continuing through daybreak on Monday, posing a risk for severe gusts and a few tornadoes. ...01z Update - TX/OK... No changes have been made to severe probabilities/categories with the 01z update. Thunderstorms will increase in coverage and intensity over the next several hours across west TX, with the severe risk increasing in the 03z-06z time period when the low-level jet begins to markedly increase. This activity is expected to quickly develop into a line/QLCS and spread east/northeast across parts of central and western north TX into southwest OK tonight into early Monday morning. Severe gusts and a few tornadoes remain possible across the broader level 1 to 3 risk area. A corridor of Enhanced risk (level 3 of 5) is expected across portions of western north TX into southwest OK closer to the deepening surface low, particularly in the 8z-12z time frame. Scattered severe gusts, some near 75 mph, and a few tornadoes are possible in this area. Uncertainty remains regarding the northward extent of greater severe potential. Surface-based instability may creep into central OK near the end of the period around 11z-12z, or perhaps just after. Regardless, strong wind field near/just above the surface may still pose a damaging wind risk, and perhaps a tornado, with early morning storms. ..Leitman.. 11/18/2024 Read more

No watches are valid as of Sun Nov 17 22:35:02 UTC 2024.

No Mesoscale Discussions are in effect as of Sun Nov 17 22:35:02 UTC 2024.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0254 PM CST Sun Nov 17 2024 Valid 191200Z - 251200Z Fire weather concerns will remain limited through much of the extended period with the exception of the southern CA coast on D3/Tuesday. The upper low currently over northern Mexico is forecast to eject into the Plains and the Midwest over the next 48 hours. Widespread rain chances will accompany this features as it shifts northeast. Additionally, an upper trough off the coast of the Pacific Northwest will continue to support widespread rain/snow chances along parts of the West Coast and Pacific Northwest through early next week. As a result, fuels will likely remain unreceptive to fire spread for most locations, though some drying is anticipated from the lower CO River Valley into the central High Plains where ensemble guidance shows relatively low probabilities for wetting precipitation. ...D3/Tue - Southern California Coast... Long-range ensemble guidance continues to trend towards a weaker surface high across the northern Great Basin during the late D2/Mon to early D4/Wed time frame. Consequently, most solutions now show low probability of reaching and/or maintaining a strong offshore pressure gradient along the southern CA coast (only a 30% chance of seeing an LAX-DAG pressure gradient of -5 mb or less). As a result, confidence in widespread critical fire weather conditions continues to wane. Latest trends suggest that the offshore pressure gradient will likely be maximized between 12-18 UTC D3/Tuesday. Elevated to locally critical fire weather conditions appear possible during this period, but may extend into early D4/Wednesday. However, confidence in prolonged elevated and/or critical conditions extending into D4/Wednesday is sufficiently low to warrant removal of the 40% risk area. ...D3/Tue - Central High Plains... The surface low associated with the ejecting upper trough (currently over northern Mexico) is forecast to reach the upper MS River Valley as it begins to occlude on D3/Tuesday. Westerly low-level winds are expected to intensify across the central Plains in response to the tightening pressure gradient with widespread 15-25 mph winds likely. Downslope trajectories off the northern Rockies may support some degree of drying across the western Dakotas into western NE, though an influx of cooler continental air should modulate RH reductions. However, limited rainfall is expected across this region through mid-week, which may allow for some drying of finer fuels. The potential for fire weather concerns appears too limited at this time given current fuel conditions and the overall RH forecast, but trends will be monitored for a wind-driven fire concern. ..Moore.. 11/17/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0155 PM CST Sun Nov 17 2024 Valid 172000Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHWEST TEXAS INTO FAR SOUTHWEST OKLAHOMA... ...SUMMARY... Scattered severe thunderstorms are expected to develop across parts of west/northwest Texas into southwest Oklahoma this evening and continuing through daybreak on Monday, posing a risk for severe gusts and a few tornadoes. ...20Z Update... ...Southern Plains... General forecast outlined in the previous discussion remain valid, with the cyclone currently entering northwest Mexico expected to continue eastward across northern Mexico before then ejecting more northeastward across the southern High Plains late tonight/early tomorrow morning. A strong mid-level jet will accompany this system, with 90-100 kt of 500-mb flow spreading across west TX and into southwest OK by early tomorrow. An intense low-level jet will develop ahead of this wave, with 60+ kt at 850-mb likely stretching from the TX Hill Country through central OK by 12Z Monday. Modest low-level moisture is still anticipated ahead of this system. Current surface analysis places the mid 60s dewpoints along and southeast of a line from PVJ in south-central OK to north of DRT in the Edwards Plateau. This area of greater low-level moisture will continue to advect northwestward throughout the day and evening, ahead of the approaching wave and associated surface low. Surface analysis also reveals a stationary boundary from END in north-central OK southwestward to just west of INK in the TX Trans Pecos. This boundary will likely provide the favored corridor for surface low progress late this evening and overnight. A strongly forced band of thunderstorm is still anticipated, beginning around 04-06Z in the Permian Basin vicinity, with this band then expected to rapidly move northeastward just ahead of the surface low, reaching central OK by 12Z. Intense low-level kinematic fields will precede this line, with strong flow associated with the mid-level jet as well. Resulting fast storm motion and downward momentum transfer supports the potential for severe gusts, despite the relatively modest thermodynamic environment. Highest probability for severe gusts is over northwest TX and far southwest OK from 09Z to 12Z Monday. A tornado risk will accompany this line as well, with the highest tornado probability in the same location and time as the greatest severe-wind threat. ..Mosier.. 11/17/2024 .PREV DISCUSSION... /ISSUED 1030 AM CST Sun Nov 17 2024/ ...Synopsis... Water-vapor imagery this morning shows a potent mid-level low/trough over northwest Mexico with a downstream ridge centered over the eastern Gulf of Mexico. A mid-level vorticity maximum near the middle part of the Gulf of California will pivot east into Chihuahua by mid evening while the larger-scale trough becomes negatively tilted and moves northeastward into the southern High Plains. In the low levels, cyclogenesis over northern Mexico will gradually evolve today before the surface low deepens tonight reaching the northwest TX/western OK vicinity at the end of the period. Seasonably moist air via southeasterly flow from the western Gulf will advect into west TX before a Pacific front sweeps eastward across the Chihuahuan Desert and portions of the southern High Plains tonight. An attendant warm frontal zone will advance northward from north TX into OK late. ...Southern Great Plains... The 12 UTC Fort Worth, TX observed sounding showed an adequately moist/deep moist layer featuring a mean mixing ratio of 12.6 g/kg. The richer low-level moisture, featuring dewpoints in the mid-upper 60s as of late morning, is currently near the I-35 corridor from the Metroplex and areas south/southeast. Moisture advection will contribute to gradual destabilization through this evening across parts of west TX northeastward into southwest OK despite considerable cloud cover through the day. As an intense 100-kt 500-mb speed max moves from Chihuahua into west TX overnight, large-scale ascent will favor the development of scattered thunderstorms initially developing near the Permian Basin vicinity and becoming more widespread as very strong low-level warm advection attendant to an intensifying LLJ develops tonight. Model guidance indicates 250-1000 J/kg MLCAPE across the destabilizing warm sector. A forced band of storms will likely evolve tonight across west TX and rapidly move northeast in the area southeast of the surface low track. As the squall line matures, the propensity for severe gusts will probably increase despite relatively poor lapse given the intense flow expected to develop. It remains uncertain if cellular development will occur either ahead of the line or be loosely maintained in parts of the larger band of storms. Nonetheless, elongated and enlarged hodographs will favor a risk for scattered severe gusts and possibly a tornado risk, especially as the squall line encounters greater moisture from west-central TX northeastward into southwest OK late. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0155 PM CST Sun Nov 17 2024 Valid 172000Z - 181200Z ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NORTHWEST TEXAS INTO FAR SOUTHWEST OKLAHOMA... ...SUMMARY... Scattered severe thunderstorms are expected to develop across parts of west/northwest Texas into southwest Oklahoma this evening and continuing through daybreak on Monday, posing a risk for severe gusts and a few tornadoes. ...20Z Update... ...Southern Plains... General forecast outlined in the previous discussion remain valid, with the cyclone currently entering northwest Mexico expected to continue eastward across northern Mexico before then ejecting more northeastward across the southern High Plains late tonight/early tomorrow morning. A strong mid-level jet will accompany this system, with 90-100 kt of 500-mb flow spreading across west TX and into southwest OK by early tomorrow. An intense low-level jet will develop ahead of this wave, with 60+ kt at 850-mb likely stretching from the TX Hill Country through central OK by 12Z Monday. Modest low-level moisture is still anticipated ahead of this system. Current surface analysis places the mid 60s dewpoints along and southeast of a line from PVJ in south-central OK to north of DRT in the Edwards Plateau. This area of greater low-level moisture will continue to advect northwestward throughout the day and evening, ahead of the approaching wave and associated surface low. Surface analysis also reveals a stationary boundary from END in north-central OK southwestward to just west of INK in the TX Trans Pecos. This boundary will likely provide the favored corridor for surface low progress late this evening and overnight. A strongly forced band of thunderstorm is still anticipated, beginning around 04-06Z in the Permian Basin vicinity, with this band then expected to rapidly move northeastward just ahead of the surface low, reaching central OK by 12Z. Intense low-level kinematic fields will precede this line, with strong flow associated with the mid-level jet as well. Resulting fast storm motion and downward momentum transfer supports the potential for severe gusts, despite the relatively modest thermodynamic environment. Highest probability for severe gusts is over northwest TX and far southwest OK from 09Z to 12Z Monday. A tornado risk will accompany this line as well, with the highest tornado probability in the same location and time as the greatest severe-wind threat. ..Mosier.. 11/17/2024 .PREV DISCUSSION... /ISSUED 1030 AM CST Sun Nov 17 2024/ ...Synopsis... Water-vapor imagery this morning shows a potent mid-level low/trough over northwest Mexico with a downstream ridge centered over the eastern Gulf of Mexico. A mid-level vorticity maximum near the middle part of the Gulf of California will pivot east into Chihuahua by mid evening while the larger-scale trough becomes negatively tilted and moves northeastward into the southern High Plains. In the low levels, cyclogenesis over northern Mexico will gradually evolve today before the surface low deepens tonight reaching the northwest TX/western OK vicinity at the end of the period. Seasonably moist air via southeasterly flow from the western Gulf will advect into west TX before a Pacific front sweeps eastward across the Chihuahuan Desert and portions of the southern High Plains tonight. An attendant warm frontal zone will advance northward from north TX into OK late. ...Southern Great Plains... The 12 UTC Fort Worth, TX observed sounding showed an adequately moist/deep moist layer featuring a mean mixing ratio of 12.6 g/kg. The richer low-level moisture, featuring dewpoints in the mid-upper 60s as of late morning, is currently near the I-35 corridor from the Metroplex and areas south/southeast. Moisture advection will contribute to gradual destabilization through this evening across parts of west TX northeastward into southwest OK despite considerable cloud cover through the day. As an intense 100-kt 500-mb speed max moves from Chihuahua into west TX overnight, large-scale ascent will favor the development of scattered thunderstorms initially developing near the Permian Basin vicinity and becoming more widespread as very strong low-level warm advection attendant to an intensifying LLJ develops tonight. Model guidance indicates 250-1000 J/kg MLCAPE across the destabilizing warm sector. A forced band of storms will likely evolve tonight across west TX and rapidly move northeast in the area southeast of the surface low track. As the squall line matures, the propensity for severe gusts will probably increase despite relatively poor lapse given the intense flow expected to develop. It remains uncertain if cellular development will occur either ahead of the line or be loosely maintained in parts of the larger band of storms. Nonetheless, elongated and enlarged hodographs will favor a risk for scattered severe gusts and possibly a tornado risk, especially as the squall line encounters greater moisture from west-central TX northeastward into southwest OK late. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0126 PM CST Sun Nov 17 2024 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE CENTRAL GULF COAST... ...SUMMARY... Thunderstorms associated with isolated severe gusts and perhaps a tornado will be possible across parts of the central Gulf states on Tuesday. ...Synopsis... A mid-level trough will amplify while traversing the Plains states and Upper MS Valley region on Tuesday, reinforcing surface high pressure and associated cooler temperatures behind a cold front poised to sweep across the OH/TN Valleys into the Southeast. As the primary surface low over the upper MS Valley ejects into Ontario through the day, surface lee troughing should occur along the central Gulf Coast, supporting continued onshore moisture advection. Given a modest, trailing low-level jet aiding in the moisture advection, enough shear and instability along the Gulf Coast may encourage strong to isolated severe thunderstorm development. ...Portions of the central Gulf Coast Region... Surface lee troughing will encourage mid to upper 60s F surface dewpoints to advect onshore amid adequate surface heating during the day, contributing to over 500 J/kg MLCAPE by afternoon. As storms intensify within a warm-air advection regime, veering/strengthening of the vertical wind profile will support modestly curved hodographs ahead of the storms. Transient supercells may develop from some of the stronger updrafts, with damaging gusts and perhaps a tornado possible. ..Squitieri.. 11/17/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0126 PM CST Sun Nov 17 2024 Valid 191200Z - 201200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE CENTRAL GULF COAST... ...SUMMARY... Thunderstorms associated with isolated severe gusts and perhaps a tornado will be possible across parts of the central Gulf states on Tuesday. ...Synopsis... A mid-level trough will amplify while traversing the Plains states and Upper MS Valley region on Tuesday, reinforcing surface high pressure and associated cooler temperatures behind a cold front poised to sweep across the OH/TN Valleys into the Southeast. As the primary surface low over the upper MS Valley ejects into Ontario through the day, surface lee troughing should occur along the central Gulf Coast, supporting continued onshore moisture advection. Given a modest, trailing low-level jet aiding in the moisture advection, enough shear and instability along the Gulf Coast may encourage strong to isolated severe thunderstorm development. ...Portions of the central Gulf Coast Region... Surface lee troughing will encourage mid to upper 60s F surface dewpoints to advect onshore amid adequate surface heating during the day, contributing to over 500 J/kg MLCAPE by afternoon. As storms intensify within a warm-air advection regime, veering/strengthening of the vertical wind profile will support modestly curved hodographs ahead of the storms. Transient supercells may develop from some of the stronger updrafts, with damaging gusts and perhaps a tornado possible. ..Squitieri.. 11/17/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0101 PM CST Sun Nov 17 2024 Valid 181200Z - 191200Z ...NO CRITICAL AREAS... The previous forecast remains on track with no areas introduced. Consideration was made for introducing an Elevated risk area to portions of the southern CA coast - namely in the lee of the San Gabriel and Sierra Madre mountains - where downslope winds are forecast to increase to above 20 mph during the early morning hours Tuesday late in the forecast period. However, confidence in seeing sufficiently widespread sub-20% RH as winds begin to increase remains limited due to weak signals in both deterministic and ensemble guidance. Pockets of elevated fire weather conditions are possible, but may be confined to the higher elevations within the thermal belt where RH will be sufficiently low. These forecast concerns precluded adding a risk area at this time. ..Moore.. 11/17/2024 .PREV DISCUSSION... /ISSUED 1246 AM CST Sun Nov 17 2024/ ...Synopsis... A strong trough will progress into the Mississippi Valley. Flow across the West will become broadly cyclonic with the strongest flow remaining roughly parallel to the California coast. Fire weather concerns are expected to remain minimal as dry and windy conditions will remain removed from the driest fuels. With the strong flow along the California coast and low-level ridging extending north of the Transverse Ranges, some stronger downslope winds are possible. RH reductions in the immediate lee of the terrain could near 20% briefly. Locally elevated conditions may occur Monday afternoon along the Santa Barbara Coast. Offshore flow in other portions of southern California will increase towards Tuesday morning. RH reductions do not appear sufficient for elevated conditions. ...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 0101 PM CST Sun Nov 17 2024 Valid 181200Z - 191200Z ...NO CRITICAL AREAS... The previous forecast remains on track with no areas introduced. Consideration was made for introducing an Elevated risk area to portions of the southern CA coast - namely in the lee of the San Gabriel and Sierra Madre mountains - where downslope winds are forecast to increase to above 20 mph during the early morning hours Tuesday late in the forecast period. However, confidence in seeing sufficiently widespread sub-20% RH as winds begin to increase remains limited due to weak signals in both deterministic and ensemble guidance. Pockets of elevated fire weather conditions are possible, but may be confined to the higher elevations within the thermal belt where RH will be sufficiently low. These forecast concerns precluded adding a risk area at this time. ..Moore.. 11/17/2024 .PREV DISCUSSION... /ISSUED 1246 AM CST Sun Nov 17 2024/ ...Synopsis... A strong trough will progress into the Mississippi Valley. Flow across the West will become broadly cyclonic with the strongest flow remaining roughly parallel to the California coast. Fire weather concerns are expected to remain minimal as dry and windy conditions will remain removed from the driest fuels. With the strong flow along the California coast and low-level ridging extending north of the Transverse Ranges, some stronger downslope winds are possible. RH reductions in the immediate lee of the terrain could near 20% briefly. Locally elevated conditions may occur Monday afternoon along the Santa Barbara Coast. Offshore flow in other portions of southern California will increase towards Tuesday morning. RH reductions do not appear sufficient for elevated conditions. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CST Sun Nov 17 2024 Valid 181200Z - 191200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF NORTHERN TEXAS INTO CENTRAL OKLAHOMA... ...SUMMARY... Thunderstorms associated with isolated severe gusts and perhaps a few tornadoes will be possible across parts of north Texas into central Oklahoma Monday morning. A marginal risk for severe gusts is expected across a relatively large area during the afternoon and evening from the eastern parts of the southern and central Plains eastward into the Ozarks and lower Mississippi Valley. ...Synopsis... A negatively tilted and pronounced mid-level trough over the southern Plains will quickly eject into the MS Valley in tandem with a rapidly deepening surface low tomorrow (Monday). A potentially severe squall line is expected to be ongoing at the start of the period across north TX into central OK. Through the afternoon though, stronger upper support should become increasingly displaced from the better low-level moisture and instability to the south, supporting a more isolated severe threat across portions of the MO Valley into the southern MS Valley later in the day toward evening. An additional round of isolated strong to potentially severe thunderstorms may also develop closer to the surface low over central and eastern KS tomorrow afternoon as well. ...Southern Plains into the MO Valley... A QLCS/squall-line should be in progress immediately ahead of a surface low across southwestern OK into northwestern TX at 12Z Monday morning. The squall line will continue to move east-northeast with the surface low amid a 70+ kt southerly low-level jet, overspread by 70-90 kts of southwesterly 500 mb flow from the ejecting trough. Large and curved hodographs should precede the squall line amid 500 J/kg SBCAPE, driven mainly by mid 60s F surface dewpoints beneath poor mid-level lapse rates. Despite meager buoyancy through the troposphere, strong forcing for ascent and impressive deep-layer/low-level shear profiles may still support severe gusts and a few tornadoes during the morning hours. Through the afternoon and evening hours, QG ascent associated with the northeastward ejecting mid-level trough, and the surface low, will outpace the richer low-level moisture closer to the Red River, which may dampen the severe threat to a degree. Nonetheless, the persistence of strong shear and forcing with the eastward-tracking squall line will support the potential for a severe gust or a tornado. ...Southeast TX into the Lower MS Valley... As the mid-level trough and surface cyclone track toward the Mid-MS Valley through the day, trailing portions of the aforementioned squall line will interact with an increasingly moist and unstable boundary layer across southeastern TX into the Lower MS Valley. Furthermore, guidance consensus shows that the entrance region of the low-level jet may also persist across eastern TX and points east ahead of the squall line, encouraging modestly elongated and curved hodographs and 200+ m2/s2 0-3 km SRH. As such, a couple of severe gusts and perhaps a tornado or two may develop if more pronounced mesovortices or embedded supercell structures can develop within the squall line. ...Central and eastern KS... Behind the initial squall line and broader cloudy/precipitation-laden WAA regime, some clearing may take place immediately ahead of the surface low track, allowing for marginal boundary-layer destabilization. As such, a couple of thunderstorms may develop ahead of the surface low amid modestly steep tropospheric lapse rates and unidirectional vertical wind profiles/strong speed shear. Any of the more robust updrafts that can develop may produce a severe gust, tornado, or instance of marginally severe hail during the afternoon. ..Squitieri.. 11/17/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1030 AM CST Sun Nov 17 2024 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are expected to develop across parts of west/northwest Texas into southwest Oklahoma this evening and continuing through daybreak on Monday, posing a risk for severe wind gusts and a few tornadoes. ...Synopsis... Water-vapor imagery this morning shows a potent mid-level low/trough over northwest Mexico with a downstream ridge centered over the eastern Gulf of Mexico. A mid-level vorticity maximum near the middle part of the Gulf of California will pivot east into Chihuahua by mid evening while the larger-scale trough becomes negatively tilted and moves northeastward into the southern High Plains. In the low levels, cyclogenesis over northern Mexico will gradually evolve today before the surface low deepens tonight reaching the northwest TX/western OK vicinity at the end of the period. Seasonably moist air via southeasterly flow from the western Gulf will advect into west TX before a Pacific front sweeps eastward across the Chihuahuan Desert and portions of the southern High Plains tonight. An attendant warm frontal zone will advance northward from north TX into OK late. ...Southern Great Plains... The 12 UTC Fort Worth, TX observed sounding showed an adequately moist/deep moist layer featuring a mean mixing ratio of 12.6 g/kg. The richer low-level moisture, featuring dewpoints in the mid-upper 60s as of late morning, is currently near the I-35 corridor from the Metroplex and areas south/southeast. Moisture advection will contribute to gradual destabilization through this evening across parts of west TX northeastward into southwest OK despite considerable cloud cover through the day. As an intense 100-kt 500-mb speed max moves from Chihuahua into west TX overnight, large-scale ascent will favor the development of scattered thunderstorms initially developing near the Permian Basin vicinity and becoming more widespread as very strong low-level warm advection attendant to an intensifying LLJ develops tonight. Model guidance indicates 250-1000 J/kg MLCAPE across the destabilizing warm sector. A forced band of storms will likely evolve tonight across west TX and rapidly move northeast in the area southeast of the surface low track. As the squall line matures, the propensity for severe gusts will probably increase despite relatively poor lapse given the intense flow expected to develop. It remains uncertain if cellular development will occur either ahead of the line or be loosely maintained in parts of the larger band of storms. Nonetheless, elongated and enlarged hodographs will favor a risk for scattered severe gusts and possibly a tornado risk, especially as the squall line encounters greater moisture from west-central TX northeastward into southwest OK late. ..Smith/Weinman.. 11/17/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1030 AM CST Sun Nov 17 2024 Valid 171630Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are expected to develop across parts of west/northwest Texas into southwest Oklahoma this evening and continuing through daybreak on Monday, posing a risk for severe wind gusts and a few tornadoes. ...Synopsis... Water-vapor imagery this morning shows a potent mid-level low/trough over northwest Mexico with a downstream ridge centered over the eastern Gulf of Mexico. A mid-level vorticity maximum near the middle part of the Gulf of California will pivot east into Chihuahua by mid evening while the larger-scale trough becomes negatively tilted and moves northeastward into the southern High Plains. In the low levels, cyclogenesis over northern Mexico will gradually evolve today before the surface low deepens tonight reaching the northwest TX/western OK vicinity at the end of the period. Seasonably moist air via southeasterly flow from the western Gulf will advect into west TX before a Pacific front sweeps eastward across the Chihuahuan Desert and portions of the southern High Plains tonight. An attendant warm frontal zone will advance northward from north TX into OK late. ...Southern Great Plains... The 12 UTC Fort Worth, TX observed sounding showed an adequately moist/deep moist layer featuring a mean mixing ratio of 12.6 g/kg. The richer low-level moisture, featuring dewpoints in the mid-upper 60s as of late morning, is currently near the I-35 corridor from the Metroplex and areas south/southeast. Moisture advection will contribute to gradual destabilization through this evening across parts of west TX northeastward into southwest OK despite considerable cloud cover through the day. As an intense 100-kt 500-mb speed max moves from Chihuahua into west TX overnight, large-scale ascent will favor the development of scattered thunderstorms initially developing near the Permian Basin vicinity and becoming more widespread as very strong low-level warm advection attendant to an intensifying LLJ develops tonight. Model guidance indicates 250-1000 J/kg MLCAPE across the destabilizing warm sector. A forced band of storms will likely evolve tonight across west TX and rapidly move northeast in the area southeast of the surface low track. As the squall line matures, the propensity for severe gusts will probably increase despite relatively poor lapse given the intense flow expected to develop. It remains uncertain if cellular development will occur either ahead of the line or be loosely maintained in parts of the larger band of storms. Nonetheless, elongated and enlarged hodographs will favor a risk for scattered severe gusts and possibly a tornado risk, especially as the squall line encounters greater moisture from west-central TX northeastward into southwest OK late. ..Smith/Weinman.. 11/17/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1005 AM CST Sun Nov 17 2024 Valid 171700Z - 181200Z The Elevated risk area has been expanded northeastward to encompass more of the New England region. This change was driven by morning surface observations, which are reporting relative humidity values between 20-25% - lower than anticipated by most model solutions. Given recent fire starts over the past 24 hours, fuels remain supportive across the region for at least a low-grade fire concern. Wind gusts up to 15 mph remain possible through early afternoon, but should still be less frequent and widespread compared to yesterday. ..Moore.. 11/17/2024 .PREV DISCUSSION... /ISSUED 1135 PM CST Sat Nov 16 2024/ ...Synopsis... With the upper-level trough and stronger mid-level flow departing to the east, surface winds are expected to weaken from previous days across the Northeast. Stronger wind gusts are also likely to be much less widespread as well. Even so, very dry conditions with very dry fuels will support a low-end elevated threat for parts of southern New England into the northern Mid-Atlantic this afternoon. Winds of 10-15 mph are possible, though these are most likely to occur earlier in the day mostly offset from the lowest RH. RH itself will fall to 25-35%, with local values near 20%. ...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 1005 AM CST Sun Nov 17 2024 Valid 171700Z - 181200Z The Elevated risk area has been expanded northeastward to encompass more of the New England region. This change was driven by morning surface observations, which are reporting relative humidity values between 20-25% - lower than anticipated by most model solutions. Given recent fire starts over the past 24 hours, fuels remain supportive across the region for at least a low-grade fire concern. Wind gusts up to 15 mph remain possible through early afternoon, but should still be less frequent and widespread compared to yesterday. ..Moore.. 11/17/2024 .PREV DISCUSSION... /ISSUED 1135 PM CST Sat Nov 16 2024/ ...Synopsis... With the upper-level trough and stronger mid-level flow departing to the east, surface winds are expected to weaken from previous days across the Northeast. Stronger wind gusts are also likely to be much less widespread as well. Even so, very dry conditions with very dry fuels will support a low-end elevated threat for parts of southern New England into the northern Mid-Atlantic this afternoon. Winds of 10-15 mph are possible, though these are most likely to occur earlier in the day mostly offset from the lowest RH. RH itself will fall to 25-35%, with local values near 20%. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0652 AM CST Sun Nov 17 2024 Valid 171300Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are expected to develop across parts of west/northwest Texas into southwest Oklahoma this evening and continuing through daybreak on Monday, posing a risk for severe wind gusts and a few tornadoes. ...Southern Plains... An upper trough/low over northwest Mexico and AZ this morning will move eastward today and eventually eject northeastward across the southern High Plains late tonight through early Monday morning. A rather strong mid-level jet (70-100 kt at 500 mb) and focused large-scale ascent will overspread much of west TX into southwest OK as this upper trough acquires a negative tilt. This will aid in the development and subsequent deepening of a surface low across northwest TX into western OK by 06-12Z Monday morning. A 50-65 kt southerly low-level jet is also expected to develop late tonight across the southern Plains, which will aid in the continued northward transport of low-level moisture. Even though surface dewpoints are forecast to increase into at least the mid 60s, poor lapse rates aloft should tend to limit the degree of instability that can develop across the warm sector tonight. Even with weak forecast instability (MLCAPE potentially up to 500-1000 J/kg) amid moist adiabatic lapse rates at low/mid levels, current expectations are for a band of thunderstorms to develop along/near a surface cold front across west TX from this evening into the early overnight hours. This band of convection will be aided by strong ascent associated with the ejecting upper trough. As the line of thunderstorms encounters somewhat better instability across west-central/northwest TX, it will likely strengthen early Monday morning while posing a threat for scattered severe winds given the forecast strength of the low/mid-level flow. Rapidly increasing winds and modest veering with height through low levels will support enlarged hodographs, with corresponding enhanced 0-1 km SRH (upwards of 200-400 m2/s2). This ample low-level shear should support a threat for a few tornadoes with circulations embedded within the east/northeastward-advancing QLCS. A warm front will extend east-northeastward from the surface low across west-central/central OK towards the end of the period early Monday morning (09-12Z). While both low-level and deep-layer shear will be quite strong, it remains unclear whether sufficient instability will be present to support surface-based convection and an appreciable severe threat across this area. Have therefore made no changes to the northern edge of the Marginal/Slight Risks with this update. ..Gleason/Kerr.. 11/17/2024 Read more

SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0652 AM CST Sun Nov 17 2024 Valid 171300Z - 181200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN PLAINS... ...SUMMARY... Scattered severe thunderstorms are expected to develop across parts of west/northwest Texas into southwest Oklahoma this evening and continuing through daybreak on Monday, posing a risk for severe wind gusts and a few tornadoes. ...Southern Plains... An upper trough/low over northwest Mexico and AZ this morning will move eastward today and eventually eject northeastward across the southern High Plains late tonight through early Monday morning. A rather strong mid-level jet (70-100 kt at 500 mb) and focused large-scale ascent will overspread much of west TX into southwest OK as this upper trough acquires a negative tilt. This will aid in the development and subsequent deepening of a surface low across northwest TX into western OK by 06-12Z Monday morning. A 50-65 kt southerly low-level jet is also expected to develop late tonight across the southern Plains, which will aid in the continued northward transport of low-level moisture. Even though surface dewpoints are forecast to increase into at least the mid 60s, poor lapse rates aloft should tend to limit the degree of instability that can develop across the warm sector tonight. Even with weak forecast instability (MLCAPE potentially up to 500-1000 J/kg) amid moist adiabatic lapse rates at low/mid levels, current expectations are for a band of thunderstorms to develop along/near a surface cold front across west TX from this evening into the early overnight hours. This band of convection will be aided by strong ascent associated with the ejecting upper trough. As the line of thunderstorms encounters somewhat better instability across west-central/northwest TX, it will likely strengthen early Monday morning while posing a threat for scattered severe winds given the forecast strength of the low/mid-level flow. Rapidly increasing winds and modest veering with height through low levels will support enlarged hodographs, with corresponding enhanced 0-1 km SRH (upwards of 200-400 m2/s2). This ample low-level shear should support a threat for a few tornadoes with circulations embedded within the east/northeastward-advancing QLCS. A warm front will extend east-northeastward from the surface low across west-central/central OK towards the end of the period early Monday morning (09-12Z). While both low-level and deep-layer shear will be quite strong, it remains unclear whether sufficient instability will be present to support surface-based convection and an appreciable severe threat across this area. Have therefore made no changes to the northern edge of the Marginal/Slight Risks with this update. ..Gleason/Kerr.. 11/17/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0340 AM CST Sun Nov 17 2024 Valid 201200Z - 251200Z ...DISCUSSION... ...Wednesday/Day 4... An upper-level trough is forecast to move through the Ohio and Tennessee Valleys on Wednesday as a cold front advances eastward through the southern and central Appalachians. Ahead of the front, surface dewpoints are forecast to be in the 60s F across much of the Carolinas into Virginia. Thunderstorms could develop ahead of the front during the day from the Mid Atlantic southward into the Carolinas, but instability is forecast to be very weak suggesting that any severe threat will remain marginal. ...Thursday/Day 5 to Sunday/Day 8... A dry and relatively stable airmass is forecast to be in place across the continental U.S. from Thursday through the weekend. As a result, severe thunderstorms are not expected during this period. Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0340 AM CST Sun Nov 17 2024 Valid 201200Z - 251200Z ...DISCUSSION... ...Wednesday/Day 4... An upper-level trough is forecast to move through the Ohio and Tennessee Valleys on Wednesday as a cold front advances eastward through the southern and central Appalachians. Ahead of the front, surface dewpoints are forecast to be in the 60s F across much of the Carolinas into Virginia. Thunderstorms could develop ahead of the front during the day from the Mid Atlantic southward into the Carolinas, but instability is forecast to be very weak suggesting that any severe threat will remain marginal. ...Thursday/Day 5 to Sunday/Day 8... A dry and relatively stable airmass is forecast to be in place across the continental U.S. from Thursday through the weekend. As a result, severe thunderstorms are not expected during this period. Read more