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No watches are valid as of Mon Dec 23 22:23:02 UTC 2024.

SPC Day 3-8 Fire Weather Outlook
Day 3-8 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0140 PM CST Mon Dec 23 2024 Valid 251200Z - 311200Z A progressive upper-air pattern will result in several mid-level troughs traversing the CONUS this week into early next week. Several instances of surface lee troughing/cyclone development are likely across the central CONUS as surface high pressure dominates the East Coast and much of the U.S. west of the Rockies. Cool conditions in the northern CONUS, as well as appreciable precipitation accumulations west of the Rockies and east of the central Plains (to the East Coast) should limit significant wildfire spread concerns over most locales. Occasionally dry and/or breezy conditions may occur over the High Plains by afternoon peak heating on several days given the anticipated frequency of surface lee trough/cyclone development over the central U.S. However, overlapping dry low-level air, stronger surface winds, and receptive fuels, should be too localized or brief to support significant wildfire-spread potential. ..Squitieri.. 12/23/2024 ...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 0136 PM CST Mon Dec 23 2024 Valid 232000Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. Only minor changes have been made to the ongoing thunderstorm forecast for the southern Plains, based on recent CAM guidance. Please see previous discussion for more details. ..Hart.. 12/23/2024 .PREV DISCUSSION... /ISSUED 1017 AM CST Mon Dec 23 2024/ ...Synopsis... A modifying air mass is returning northward into TX from the western Gulf basin, and continued low-level warming/moistening will result in gradual destabilization. Modest amplification of a midlevel trough over the southern High Plains, in combination with an increasingly moist warm advection regime, will support the potential for a few elevated thunderstorms this evening into tonight across parts of OK/north TX. There is also a small chance for near-surface-based thunderstorms along a confluence zone from Matagorda Bay northward into the western parts of southeast TX. Otherwise, a midlevel trough over the eastern Pacific will approach northern CA late in the period, when weak destabilization could support sufficiently deep convection for isolated lightning flashes. Farther east, the potential for deep convection will increase through the period in association with air mass modification and weak cyclogenesis in the vicinity of the Gulf Stream. However, the potential for thunderstorms is expected to remain offshore. Read more

SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0136 PM CST Mon Dec 23 2024 Valid 232000Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. Only minor changes have been made to the ongoing thunderstorm forecast for the southern Plains, based on recent CAM guidance. Please see previous discussion for more details. ..Hart.. 12/23/2024 .PREV DISCUSSION... /ISSUED 1017 AM CST Mon Dec 23 2024/ ...Synopsis... A modifying air mass is returning northward into TX from the western Gulf basin, and continued low-level warming/moistening will result in gradual destabilization. Modest amplification of a midlevel trough over the southern High Plains, in combination with an increasingly moist warm advection regime, will support the potential for a few elevated thunderstorms this evening into tonight across parts of OK/north TX. There is also a small chance for near-surface-based thunderstorms along a confluence zone from Matagorda Bay northward into the western parts of southeast TX. Otherwise, a midlevel trough over the eastern Pacific will approach northern CA late in the period, when weak destabilization could support sufficiently deep convection for isolated lightning flashes. Farther east, the potential for deep convection will increase through the period in association with air mass modification and weak cyclogenesis in the vicinity of the Gulf Stream. However, the potential for thunderstorms is expected to remain offshore. Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0123 PM CST Mon Dec 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Christmas Day (Wednesday). ...Synopsis... A mid-level trough will weaken as it moves from East Texas to the Southeast on Wednesday. Some remnant thunderstorms may persist early in the period, but should weaken by the afternoon as mid-level heights rise and forcing weakens. A second, stronger mid-level trough will advance across the Southwest and become a closed mid-level low across the northeastern New Mexico vicinity by the end of the period. Surface moisture will remain across far southeast Texas on Wednesday night, but a strengthening low-level jet ahead of the mid-level trough may result in some moistening in the 1 to 3 km layer and some weak elevated instability by the end of the period across West Texas into the Texas Panhandle. This combined with forcing for ascent, may result in a few thunderstorms near 12Z Thursday. No severe storms are anticipated due to the weak instability. In addition, a mid-level shortwave trough will move onto the Oregon coast after 06Z Thu. Forecast soundings ahead of the associated surface front show mostly moist-adiabatic thermal profiles, but some weak instability may be present and result in a few thunderstorms. ..Bentley.. 12/23/2024 Read more

SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0123 PM CST Mon Dec 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Christmas Day (Wednesday). ...Synopsis... A mid-level trough will weaken as it moves from East Texas to the Southeast on Wednesday. Some remnant thunderstorms may persist early in the period, but should weaken by the afternoon as mid-level heights rise and forcing weakens. A second, stronger mid-level trough will advance across the Southwest and become a closed mid-level low across the northeastern New Mexico vicinity by the end of the period. Surface moisture will remain across far southeast Texas on Wednesday night, but a strengthening low-level jet ahead of the mid-level trough may result in some moistening in the 1 to 3 km layer and some weak elevated instability by the end of the period across West Texas into the Texas Panhandle. This combined with forcing for ascent, may result in a few thunderstorms near 12Z Thursday. No severe storms are anticipated due to the weak instability. In addition, a mid-level shortwave trough will move onto the Oregon coast after 06Z Thu. Forecast soundings ahead of the associated surface front show mostly moist-adiabatic thermal profiles, but some weak instability may be present and result in a few thunderstorms. ..Bentley.. 12/23/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0117 PM CST Mon Dec 23 2024 Valid 241200Z - 251200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track. ..Squitieri.. 12/23/2024 .PREV DISCUSSION... /ISSUED 0101 AM CST Mon Dec 23 2024/ ...Synopsis... Breezy southerly surface winds will overspread the southern Great Basin ahead of an amplified midlevel trough, though marginal RH and fuels will preclude a 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 0117 PM CST Mon Dec 23 2024 Valid 241200Z - 251200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track. ..Squitieri.. 12/23/2024 .PREV DISCUSSION... /ISSUED 0101 AM CST Mon Dec 23 2024/ ...Synopsis... Breezy southerly surface winds will overspread the southern Great Basin ahead of an amplified midlevel trough, though marginal RH and fuels will preclude a fire-weather risk. ...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 1118 AM CST Mon Dec 23 2024 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS SOUTH-CENTRAL/EAST TEXAS... ...SUMMARY... A few locally severe storms could occur across parts of central and East Texas on Tuesday. ...Synopsis... On Tuesday a progressive upper-level pattern will be present with a positively tilted mid-level trough advancing off the New England Coast, a mid-level trough amplifying across the southern Plains, and a stronger trough moving from off the California coast to the Southwest during the forecast period. Inland low-level moisture will result in some instability, adequate for thunderstorms across portions of the southern Plains. A few of these storms may be severe across central/east Texas. ...Central/East Texas... Thunderstorms will likely be ongoing at the beginning of the period within the warm air advection zone across eastern Oklahoma. South of this activity, isolated convection may be possible within a region of broad ascent associated with a 30 to 35 knot low-level jet. Instability and shear will likely be too weak for severe thunderstorms from this activity. However, by Tuesday afternoon/evening, continued moisture advection and some weak surface heating should result in greater instability along and south of the cold front/composite outflow across northeast Texas. In addition to the greater instability, forcing will increase ahead of the approaching trough and mid-level flow will strengthen. This will likely result in scattered convection amid weak to moderate instability and 30 to 35 knots of shear. Some transient supercell structures may be possible along and ahead of the cold front as it advances southeast through the afternoon and evening. While the low-level flow is forecast to be quite weak, particularly across southeast Texas where instability will be greatest, forecast hodographs do show significant clockwise curvature in the lowest 1 to 2 km. Therefore, a tornado cannot be ruled out, particularly with any stronger/longer-lived supercells which may develop. ...Northern California/Pacific Northwest... As a prominent upper-level trough and related frontal band moves inland, isolated thunderstorms will be possible across northern California coastal areas and the adjacent Central Valley on Tuesday morning with the frontal band and later in the day with post-frontal cellular convection as low/mid-level lapse rates steepen. A more limited/isolated thunderstorm potential will also exist across other parts of the coastal Pacific Northwest. ..Bentley.. 12/23/2024 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1017 AM CST Mon Dec 23 2024 Valid 231630Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...Synopsis... A modifying air mass is returning northward into TX from the western Gulf basin, and continued low-level warming/moistening will result in gradual destabilization. Modest amplification of a midlevel trough over the southern High Plains, in combination with an increasingly moist warm advection regime, will support the potential for a few elevated thunderstorms this evening into tonight across parts of OK/north TX. There is also a small chance for near-surface-based thunderstorms along a confluence zone from Matagorda Bay northward into the western parts of southeast TX. Otherwise, a midlevel trough over the eastern Pacific will approach northern CA late in the period, when weak destabilization could support sufficiently deep convection for isolated lightning flashes. Farther east, the potential for deep convection will increase through the period in association with air mass modification and weak cyclogenesis in the vicinity of the Gulf Stream. However, the potential for thunderstorms is expected to remain offshore. ..Thompson/Moore.. 12/23/2024 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1009 AM CST Mon Dec 23 2024 Valid 231700Z - 241200Z ...NO CRITICAL AREAS... The previous forecast (see below) remains on track. ..Squitieri.. 12/23/2024 .PREV DISCUSSION... /ISSUED 0100 AM CST Mon Dec 23 2024/ ...Synopsis... Fire-weather concerns will be minimal today. Locally dry/breezy conditions are possible in the vicinity of a weak lee cyclone over the southern High Plains, though surface winds should remain too light for a fire-weather threat. ...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 0642 AM CST Mon Dec 23 2024 Valid 231300Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast through tonight across the contiguous United States. ...Synopsis... Water-vapor imagery this morning shows a mid-level trough over AZ moving east and a northern stream trough over the Pacific Northwest. The northern mid-level trough will latitudinally expand southward into the central Rockies/south-central High Plains as a ridge amplifies over the Interior West in its wake. As this occurs, a partial phasing of mid-level trough over the Desert Southwest will occur as it moves into the southern High Plains. Farther west, a powerful upper trough will reach the WA/OR/northern CA coasts late tonight. In the low levels, surface high pressure will influence conditions over much of the Lower 48 states. Weak/ill-defined lower pressure over central TX will facilitate southerly flow from the TX coastal plain northward into the Red River Valley. Weak 850-mb warm-air advection will likely persist through the period across north TX into OK while a modest increase in moisture eventually results in weak elevated instability. Isolated to widely scattered showers and a few thunderstorms are possible tonight over eastern OK and perhaps as far south as north TX. ..Smith/Goss.. 12/23/2024 Read more

Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0355 AM CST Mon Dec 23 2024 Valid 261200Z - 311200Z ...DISCUSSION... Severe-weather potential is still expected for Days 4-6 Thursday-Saturday, as an upper trough emerging from California and the Southwest deserts moves toward the Ozarks/Deep South by Thursday/Day 4. At least a low-end multi-day regional severe risk is expected across south-central and east/southeast Texas towards parts of the ArkLaTex, and possibly the Lower Mississippi Valley. In particular, Thursday/Day 4 could ultimately warrant Slight Risk-caliber severe probabilities across south-central to east/southeast Texas although guidance variability persists, while objective/machine-learning guidance generally also persist with sub-15 percent probabilities. Read more

SPC 0830Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0220 AM CST Mon Dec 23 2024 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Christmas Day (Wednesday). ...Discussion... A lead southern-stream shortwave trough will tend to weaken across the Lower Mississippi Valley/Tennessee Valley on Wednesday, while a secondary shortwave trough modestly amplifies as it progresses east-southeastward over the southern Rockies toward far west Texas Wednesday night. Some thunderstorms may linger during the day across Louisiana and the upper Texas coast, and possibly into other parts of the Lower Mississippi Valley. Related to the secondary shortwave trough, isolated elevated thunderstorm development may also occur late Wednesday night across far eastern New Mexico into west/northwest Texas including the Texas Panhandle, with forecast soundings plausibly showing a couple hundred J/kg MUCAPE across this region by daybreak (12z) Thursday. Additionally, a few thunderstorms could again occur near the coastal Pacific Northwest/northern California Wednesday night as a shortwave trough/frontal band approaches and mid-level lapse rates steepen. Little or no severe-weather potential is currently expected with any of these scenarios, largely attributable to minimal buoyancy in each instance. ..Guyer.. 12/23/2024 Read more

SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CST Mon Dec 23 2024 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS SOUTH-CENTRAL/EAST TEXAS... ...SUMMARY... A few locally severe storms could occur across parts of central and East Texas on Tuesday. ...Central/East Texas... A southern-stream shortwave trough will amplify and spread east-southeastward on Tuesday across the south-central Plains toward the Ozarks. Low-level moisture will modestly increase across the Texas coastal plain into south-central/east Texas during the day. Lower 60s F surface dewpoints will become increasingly common inland ahead a southeast-moving cold front that will extend from north-central Texas southwestward toward the Edwards Plateau Tuesday afternoon. In proximity to a surface wave and near/north of a warm front, scattered convection should be ongoing Tuesday morning across far north/northeast Texas and the ArkLaTex vicinity/southeast Oklahoma. Modest diurnal destabilization (up to 750-1000 J/kg MLCAPE) should occur ahead of the southeastward-moving effective cold front, mainly across south-central to east/southeast Texas including the I-35/I-45 corridors. As this occurs, a diurnally related intensification of storms is expected near the southeast-advancing front, and possibly also in the nearby free warm sector during the afternoon. A few of these storms could be severe. Effective shear will not be overly strong (30-35 kt), including some flow weakness continuing to be noted in model soundings around 2-3 km AGL. Even so, some organized storm modes including weak/transient supercells could occur with marginally severe hail and/or a few locally severe wind gusts, mainly during the afternoon and evening. ...Northern California/Pacific Northwest... As a prominent upper-level trough and related frontal band moves inland, isolated thunderstorms will be possible across northern California coastal areas and interior valley on Tuesday, early in the day with the frontal band and with post-frontal cellular convection during the day as low/mid-level lapse rates steepen. A more limited/isolated thunderstorm potential will also exist across other parts of the coastal Pacific Northwest. ..Guyer.. 12/23/2024 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 0101 AM CST Mon Dec 23 2024 Valid 241200Z - 251200Z ...NO CRITICAL AREAS... ...Synopsis... Breezy southerly surface winds will overspread the southern Great Basin ahead of an amplified midlevel trough, though marginal RH and fuels will preclude a fire-weather risk. ..Weinman.. 12/23/2024 ...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 0100 AM CST Mon Dec 23 2024 Valid 231200Z - 241200Z ...NO CRITICAL AREAS... ...Synopsis... Fire-weather concerns will be minimal today. Locally dry/breezy conditions are possible in the vicinity of a weak lee cyclone over the southern High Plains, though surface winds should remain too light for a fire-weather threat. ..Weinman.. 12/23/2024 ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1117 PM CST Sun Dec 22 2024 Valid 231200Z - 241200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today. A few thunderstorms are expected over parts of the Southern Plains. ...Synopsis and Discussion... An upper trough will extend from Quebec southwestward toward the Upper Great Lakes today, moving into the Northeast by Tuesday morning. To the west, an upper ridge will rapidly amplify along the West Coast as a deep upper trough approaches late. In advance of the amplifying ridge over the Intermountain West, weak troughiness will develop over the Plains. At the surface, high pressure will remain over the East, while a weak trough develops over the southern Plains. To the west of this surface trough, weak cold front will push south across the central and southern High Plains, while southerly winds bring moisture northward over central TX. The greatest probability of general thunderstorms appears to be over parts of TX into southern OK, during the evening and overnight. Here, southwest 850 mb flow over 30 kt will aid moisture advection and elevated destabilization. Weak shear and instability will preclude any severe chances. Elsewhere, increasing warm advection and moistening ahead of the western trough late in the day will bring widespread precipitation to WA, OR, and northern CA. A low chance of a few lightning flashes will exist over northern CA, with overall coverage should remain low. ..Jewell/Weinman.. 12/23/2024 Read more

SPC 0100Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0656 PM CST Sun Dec 22 2024 Valid 230100Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast across the contiguous United States through tonight. ...Synopsis... An upper trough currently exists along the coastal Pacific Northwest this evening, and height rises will occur tonight as the wave moves northeastward across OR and WA. In the near term, a few thunderstorms will remain possible over coastal northern CA, and farther north across western WA beneath the cooler air aloft. Most of the instability is elevated over southern areas, but weak SBCAPE may exist near coastal WA. Here, low-level flow will veer to westerly coincident with the stronger midlevel cooling, supporting non-severe, low-topped convection. ..Jewell.. 12/23/2024 Read more