528 ACUS01 KWNS 130031 SWODY1 SPC AC 130030 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0730 PM CDT Sun Oct 12 2025 Valid 130100Z - 131200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast tonight. ...01z Update... Onset of nocturnal cooling will lead to a stabilizing boundary layer across most of the CONUS over the next few hours. Latest lightning data supports this with a decrease in thunderstorm activity as buoyancy weakens. Modest instability lingers across the lower deserts of the Southwest where roughly 1000 J/kg MLCAPE is noted along the international border of southwest AZ, but meager instability is noted elsewhere. Even so, thunderstorms are weakening across southern AZ, and 00z sounding from TUS was not particularly impressive with only 6 C/km midlevel lapse rates. This yielded around 600 J/kg MLCAPE, and further weakening is expected over the next few hours. While gusty winds may accompany the most robust convection early this evening, severe threat appears too low to warrant probabilities overnight. ..Darrow.. 10/13/2025 $$  244 ACUS01 KWNS 130519 SWODY1 SPC AC 130518 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1218 AM CDT Mon Oct 13 2025 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE SOUTHWESTERN U.S.... ...SUMMARY... Isolated, marginally severe hail and wind will be possible from the Four Corners and eastern Arizona to the Texas Trans-Pecos this afternoon into mid-evening. Locally damaging winds are possible later tonight along the south-central portion of coastal California. ...Southwestern U.S... Strong upper low is currently located along the WA Coast, shifting south in line with latest model guidance. This feature will continue to dig south as the primary midlevel speed max has yet to round the base of the trough. Left-exit region of the jet max will approach the central CA Coast after 14/06z which should encourage low-topped convection to move onshore after midnight. This activity could be locally strong with some gust potential as scattered convection advances inland in association with a pronounced cold front. Forecast soundings yield little more than 500 J/kg MLCAPE so any hail that forms with this activity should remain below severe levels. Downstream, deep south-southwesterly tropical feed across northwest Mexico into the southern Rockies will continue. Considerable amount of clouds and scattered precipitation should limit lapse rates and instability across this region. Even so, strong 0-6km shear does favor organized updrafts, especially during the afternoon/early evening when air mass will be most unstable. A low risk for hail/wind can be expected with the most robust convection, but widespread severe is not anticipated due to aforementioned poor lapse rates/modest buoyancy. ..Darrow/Weinman.. 10/13/2025 $$  266 ACUS02 KWNS 130556 SWODY2 SPC AC 130555 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1255 AM CDT Mon Oct 13 2025 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF FAR WEST TEXAS...NEW MEXICO AND SOUTHERN CALIFORNIA... ...SUMMARY... Thunderstorms with marginally severe wind gusts and hail will be possible on Tuesday across parts of far west Texas and New Mexico from mid afternoon into the early evening. An isolated tornado and wind-damage threat will be possible around midday Tuesday along the coast in southern California. ...Far West Texas/New Mexico... At mid-levels, a ridge will remain over the central U.S. on Tuesday, as a low moves eastward across central California. Southwesterly flow will be in place from the Desert Southwest into the southern and central Rockies. Along the southeastern periphery of the stronger flow, an axis of instability will be in place by Tuesday afternoon from far west Texas northward into central and northeastern New Mexico. As surface temperatures warm during the day near the instability axis, isolated to scattered thunderstorms will form in the higher terrain and spread northeastward into the lower elevations. Near the instability axis, MLCAPE is forecast to peak in the 1000 to 1200 J/kg range. The instability combined with moderate deep-layer shear and steep low-level lapse rates should be enough for a marginal severe threat from mid afternoon into early evening. Isolated severe wind gusts and hail will be the primary threats. ...Southern California Coast... A mid-level low will move across central California on Tuesday, as an associated trough moves inland across southern California. Thunderstorm development will likely take place near the trough, along a focused band of large-scale ascent. The storms will form near the axis of 80 to 90 knot mid-level jet, which will contribute to strong deep-layer shear. Forecast soundings along the coast from Los Angeles to San Diego around midday on Tuesday have 0-6 km shear near 80 knots, with 0-3 km storm-relative helicity in the 150 to 250 m2/s2 range. This could be enough for a marginal tornado and wind-damage threat, mainly with low-topped rotating storms that move inland. ..Broyles.. 10/13/2025 $$  915 ACUS03 KWNS 130729 SWODY3 SPC AC 130729 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0229 AM CDT Mon Oct 13 2025 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN ROCKIES AND CENTRAL HIGH PLAINS... ...SUMMARY... An isolated severe threat is expected to develop from Wednesday into Wednesday night across parts of the southern Rockies, and in the central High Plains. Marginally severe wind gusts and hail will be the primary threats. ...Southern Rockies... A mid-level ridge will be located over the central U.S. on Wednesday, as cyclonic mid-level flow remains in place from the Desert Southwest into the central Rockies. Along the southeastern periphery of the stronger flow, a north-to-south axis of instability is forecast from southwest New Mexico into southern Colorado. Warming surface temperatures during the day will aid convective initiation in the higher terrain during the afternoon. Storms will move northeastward into the lower elevations. Steep low-level lapse rates and moderate deep-layer shear should be enough for an isolated severe threat. Marginally severe wind gusts and hail will be possible with the stronger cores. ...Central High Plains... A mid-level low will move northeastward through the Intermountain West on Wednesday, as an associated 70 to 80 knot jet streak moves through the Four Corners region. The exit region of the jet will overspread the central High Plains Wednesday night, providing a broad zone of large-scale ascent that will aid scattered thunderstorm development. At the surface, a lee trough will develop and steadily deepen in the central High Plains on Wednesday. A warm front will move northward into western and central Nebraska as an east-southeast-to-west-northwest axis of low-level moisture becomes increasingly defined behind the front. Instability is forecast to become maximized during the evening at the western end of the moist axis over western Nebraska and far southeastern Wyoming. This pocket of instability is forecast to move northward into western South Dakota by late evening. In addition to the instability, deep-layer shear will steadily increase across the central High Plains as the jet streak approaches, making conditions supportive of an isolated severe threat. Cells that develop within the area of strongest instability may have potential for marginally severe wind gusts and hail. ..Broyles.. 10/13/2025 $$  252 ACUS48 KWNS 130900 SWOD48 SPC AC 130858 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0358 AM CDT Mon Oct 13 2025 Valid 161200Z - 211200Z ...DISCUSSION... ...Thursday/Day 4 to Saturday/Day 6... On Thursday, a mid-level ridge is forecast to move eastward into the Mississippi Valley, as a low and an associated shortwave trough move northeastward into the northern Rockies and northern Plains. Thunderstorm development is expected Thursday afternoon along and ahead of a cold front from central Nebraska into the eastern Dakotas. An isolated severe threat will be possible, but should be marginal due to weak instability. From Friday into Saturday, a large-scale mid-level trough is forecast to move eastward from the central Rockies and Intermountain West into the Great Plains. Scattered thunderstorms will be possible Friday afternoon and evening ahead of the trough along and near an axis of instability from Oklahoma northeastward into northwest Missouri. Forecast instability and deep-layer shear appear sufficient for an isolated severe threat. Friday night, low-level moisture advection is forecast to markedly increase as surface dewpoints in the lower to mid 60s F overspread the Ark-La-Tex, Ozarks and mid Mississippi Valley. Moderate instability is expected to develop early in the day on Saturday across parts of the moist sector, where moderate to strong deep-layer shear will be in place. Thunderstorms that form along and near the axis of strongest instability should obtain a severe threat. Supercells with severe wind gusts, hail and tornado potential will be possible. The magnitude of the severe threat will be greatest in areas that remain unaffected by morning thunderstorm activity. The severe threat should spread eastward into the lower to mid Mississippi Valley Saturday evening and into the overnight period. Although lingering uncertainties exist, confidence in the model solutions is great enough to add a 15 percent area over parts of Ark-La-Tex, Ozarks and lower to mid Mississippi Valley. ...Sunday/Day 7 and Monday/Day 8... The mid-level trough is forecast to move eastward across the lower to mid Mississippi Valley on Sunday and to the mid Atlantic Seaboard on Monday. Thunderstorms will be ongoing Sunday morning, ahead of a cold front moving through the Ohio and Tennessee Valleys. New convective development is expected during the day on Sunday ahead of the front as surface temperatures warm. Thunderstorm development should also occur on Monday ahead of the front. However, instability is forecast to remain relatively weak across much of the moist sector on Sunday and Monday, suggesting the severe threat in most areas will remain relatively isolated. ..Broyles.. 10/13/2025  455 ACUS01 KWNS 131237 SWODY1 SPC AC 131236 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0736 AM CDT Mon Oct 13 2025 Valid 131300Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF COASTAL CALIFORNIA...AND THE SOUTHWEST INTO FAR WEST TEXAS... ...SUMMARY... Isolated, marginally severe hail and wind may occur from the Four Corners region and eastern Arizona to far west Texas this afternoon and evening. Locally damaging winds appear possible mainly tonight along parts of south-central coastal California. ...Coastal California... An upper trough/low over the coastal Pacific Northwest this morning will dig southward along the CA Coast through tonight. An attendant strong mid-level jet will round the base of this trough and overspread parts of coastal south-central CA this evening into early Tuesday morning. Strong forcing for ascent with this jet should support low-topped convection along/ahead of a surface cold front. Even though low-level moisture and related instability are expected to remain quite limited with poor lapse rates present, strong flow aloft may still support gusty to locally severe/damaging winds as convection spreads east-southeastward along parts of the CA Coast late this evening and overnight. ...Southwest into Far West Texas... Between the upper trough/low over the West Coast and upper ridging centered over much of the Plains, a fetch of low/mid-level moisture with tropical origins will persist today over parts of the Southwest. Mid-level lapse rates will remain poor, but diurnal heating should gradually destabilize the airmass this afternoon, with scattered to numerous convection forecast to once again initially develop over the higher terrain of AZ into the Four Corners region. Strong deep-layer shear may support some updraft organization, with isolated hail and gusty winds possible with the more robust cores. A somewhat separate corridor of strong to isolated severe thunderstorms may develop northeastward late this afternoon and evening off the higher terrain of north-central Mexico into portions of far west TX. ..Gleason/Squitieri.. 10/13/2025 $$  441 ACUS01 KWNS 131546 SWODY1 SPC AC 131545 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1045 AM CDT Mon Oct 13 2025 Valid 131630Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS LATER TODAY OVER CENTRAL AND SOUTHEAST ARIZONA...AND LATE TONIGHT OVER SOUTH-CENTRAL COASTAL CALIFORNIA.... ...SUMMARY... Isolated, marginally severe hail and wind may occur this afternoon and evening over parts of central and southeastern Arizona. Locally damaging winds appear possible late tonight along parts of south-central coastal California. ...AZ... An upper low currently centered along the OR coast will dig southward through the forecast period. This will maintain deep southwesterly flow throughout the Southwest US and Great Basin. Considerable mid-level moisture and marginal CAPE values will promote a risk of scattered thunderstorms across these areas through tonight. While an isolated strong storm will be possible over a broad region, parts of the central and southeast AZ appear to have the best combination of daytime heating, orographic ascent, and vertical shear to promote a risk of a few strong/severe storms capable of hail and gusty winds. ...Coastal CA... A strong mid-level jet max will rotate inland tonight into parts of south-central coastal CA, along with an associated surface cold front. Forecast soundings along/ahead of the front show sufficient CAPE and vertical shear for a risk of a few low-topped but strong storms capable of damaging wind gusts or perhaps a tornado. The main concerns will be after midnight. ..Hart/Moore.. 10/13/2025 $$  927 ACUS02 KWNS 131710 SWODY2 SPC AC 131708 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1208 PM CDT Mon Oct 13 2025 Valid 141200Z - 151200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF NEW MEXICO...AND COASTAL SOUTHERN CALIFORNIA... ...SUMMARY... Thunderstorms with marginally severe wind gusts and hail will be possible on Tuesday across parts New Mexico from late afternoon into the evening. An isolated tornado and wind-damage threat will be possible Tuesday morning through midday along the coast in southern California. ...Synopsis... A deep upper low will fill as it moves from central CA into NV on Tuesday. A midlevel speed max will move into southern CA early in the day, nosing northeastward into southern UT into Wednesday. Cold temperatures aloft will exist on the north side of the jet, which will favor scattered daytime convection due to heating. Ahead of this system, and west of a southern Plains ridge, southerly winds will maintain a plume of moisture across much of NM and into CO. As this area will be well east of the upper low, temperatures aloft will remain relatively warm. ...Coastal Southern CA... A band of rain and thunderstorms is likely to be ongoing Tuesday morning along a cold front, extending well offshore. This arcing line of convection will be supported by very cold temperatures aloft north of the midlevel speed max, with SBCAPE values of a couple hundred J/kg. Although low-topped, sufficient buoyancy in the low-levels combined with veering winds with height and organization along a boundary may result in isolated severe weather, with damaging gusts and perhaps a brief/weak tornado. This convection will likely be strongest from morning to midday, eventually weakening across southern parts of the Marginal Risk area as that portion of the front interacts with warmer temperatures aloft. ...NM... Instability will gradually increase through late afternoon within the theta-e plume with persistent southerly flow. It appears the primary risk will occur late in the day/evening, as full destabilization is persisted into the night due to the established moist plume. Subtle height falls may occur late, and several CAMs suggest nocturnal development with storms racing northward across central portions of NM. Given robust shear profiles, a few storms could contain marginal hail or gusty winds. ..Jewell.. 10/13/2025 $$  526 ACUS03 KWNS 131929 SWODY3 SPC AC 131927 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0227 PM CDT Mon Oct 13 2025 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL HIGH PLAINS AND SOUTHERN ROCKIES... ...SUMMARY... Isolated severe storms are possible on Wednesday across parts of the southern Rockies, and over the central High Plains. Areas of hail will be the primary risk, with sporadic strong gusts possible. ...Synopsis and Discussion... An upper low over UT will pivot northeastward toward the northern Rockies, with a belt of strong mid and high level flow moving across the Rockies and into the central and northern High Plains by Thursday morning. Low pressure will develop over eastern CO and WY during the afternoon, and will move into the Dakotas overnight. Surface moisture return will be limited due to a large area of high pressure over the Great Lakes, with poor trajectories extending south into the northern Gulf of America. However, cooling aloft with the upper trough and an existing plume of midlevel moisture will aid destabilization. By late afternoon, MUCAPE of 500-1000 J/kg is forecast over central NM, and from northeast CO into western NE. Early day precip may hamper destabilization in parts of the southern Rockies, but a few storms could produce marginal hail. Farther north into CO/WY/NE, isolated severe storms producing hail appear more likely as instability is more likely to be at or above 1000 J/kg, along with long hodographs. Further, an increasing southerly low-level jet may aid storm longevity into the evening into western SD. ..Jewell.. 10/13/2025 $$  304 ACUS11 KWNS 131942 SWOMCD SPC MCD 131941 AZZ000-132145- Mesoscale Discussion 2144 NWS Storm Prediction Center Norman OK 0241 PM CDT Mon Oct 13 2025 Areas affected...Central Arizona Concerning...Severe potential...Watch unlikely Valid 131941Z - 132145Z Probability of Watch Issuance...5 percent SUMMARY...Thunderstorms are expected to increase in coverage through the evening hours. Sporadic hail and severe gusts appear possible. DISCUSSION...Over the past hour, convective intensity has increased slightly per GOES IR imagery and lightning trends. This comes as temperatures on the western periphery of a more expansive cloud shield continue to warm into the upper 70s and low 80s, which is supporting MLCAPE values upwards of 500-1000 J/kg. The KIWA VWP continues to sample elongated/straight hodographs with 0-6 km BWD values on the order of 50 knots. A recent cell split over south-central AZ provides further evidence of this favorable kinematic environment. The combination of continued daytime heating, very weak capping, and orographic ascent should promote an increase in thunderstorm coverage through the late afternoon and evening hours. Despite the strong wind shear, modest mid-level lapse rates and meager forcing for ascent (mainly associated with gradual height falls ahead of an approaching upper wave) will likely promote somewhat anemic thunderstorms that exhibit periods of intensification to near severe limits as they sufficiently deepen to realize the full kinematic profile. While a few instances of severe gusts and large hail appear possible - particularly during the 20-00 UTC period - confidence in a widespread/prolonged severe threat remains limited. ..Moore/Hart.. 10/13/2025 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...TWC...FGZ...PSR... LAT...LON 35021221 34441061 34171018 33860991 33580988 33180998 32861027 32541071 32421111 32401142 32421181 33071263 33431286 33861310 34321321 34711313 34921292 35021259 35021221 MOST PROBABLE PEAK WIND GUST...UP TO 60 MPH MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN  847 ACUS01 KWNS 131947 SWODY1 SPC AC 131945 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0245 PM CDT Mon Oct 13 2025 Valid 132000Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING ACROSS CENTRAL AND SOUTHEAST AZ...AND LATE TONIGHT OVER SOUTH-CENTRAL COASTAL CA... ...SUMMARY... Isolated, marginally severe hail and wind may occur this afternoon and evening over parts of central and southeastern Arizona. Locally damaging winds appear possible late tonight along parts of south-central coastal California. ...20Z Update... ...AZ... Southwesterly flow aloft will persist throughout the afternoon/evening and overnight. This flow, coupled with modest mid-level moisture and buoyancy will promote a continued threat for isolated strong thunderstorms, a few of which may be capable of hail and/or gusty winds. MCD #2144 was recently issued to address this isolated severe potential. ...Coastal Central/Southern CA... The deep upper low currently just off the northern CA coast will continue to progress southward tonight, ending the period just off the central CA coast. A strong mid-level jet max will rotate around this low as it progresses southward, spreading eastward into southern CA late tonight/early tomorrow. A strong frontal band is anticipated along the leading edge of the ascent associated with this speed max. Current guidance places this band near the coast around 05Z/06Z before then moving inland over the next few hours. Thermodynamic profiles indicate predominantly shallow convection within and ahead of this frontal band, although a few lightning flash are possible (most likely within the frontal band itself). Additionally, the combination of modest buoyancy and strong deep-layer vertical shear could result in rotation within any more persistent updrafts, with an attendant threat for damaging gusts and/or a brief tornado. Even so, the modest and shallow buoyancy should keep updrafts transient, and any rotation within those updrafts short lived, keeping the overall severe potential low. ..Mosier.. 10/13/2025 .PREV DISCUSSION... /ISSUED 1045 AM CDT Mon Oct 13 2025/ ...AZ... An upper low currently centered along the OR coast will dig southward through the forecast period. This will maintain deep southwesterly flow throughout the Southwest US and Great Basin. Considerable mid-level moisture and marginal CAPE values will promote a risk of scattered thunderstorms across these areas through tonight. While an isolated strong storm will be possible over a broad region, parts of the central and southeast AZ appear to have the best combination of daytime heating, orographic ascent, and vertical shear to promote a risk of a few strong/severe storms capable of hail and gusty winds. ...Coastal CA... A strong mid-level jet max will rotate inland tonight into parts of south-central coastal CA, along with an associated surface cold front. Forecast soundings along/ahead of the front show sufficient CAPE and vertical shear for a risk of a few low-topped but strong storms capable of damaging wind gusts or perhaps a tornado. The main concerns will be after midnight. $$  644 ACUS03 KWNS 132132 SWODY3 SPC AC 132131 Day 3 Convective Outlook RESENT 1 NWS Storm Prediction Center Norman OK 0431 PM CDT Mon Oct 13 2025 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL HIGH PLAINS AND SOUTHERN ROCKIES... ...SUMMARY... Isolated severe storms are possible on Wednesday across parts of the southern Rockies, and over the central High Plains. Areas of hail will be the primary risk, with sporadic strong gusts possible. ...Synopsis and Discussion... An upper low over UT will pivot northeastward toward the northern Rockies, with a belt of strong mid and high level flow moving across the Rockies and into the central and northern High Plains by Thursday morning. Low pressure will develop over eastern CO and WY during the afternoon, and will move into the Dakotas overnight. Surface moisture return will be limited due to a large area of high pressure over the Great Lakes, with poor trajectories extending south into the northern Gulf of America. However, cooling aloft with the upper trough and an existing plume of midlevel moisture will aid destabilization. By late afternoon, MUCAPE of 500-1000 J/kg is forecast over central NM, and from northeast CO into western NE. Early day precip may hamper destabilization in parts of the southern Rockies, but a few storms could produce marginal hail. Farther north into CO/WY/NE, isolated severe storms producing hail appear more likely as instability is more likely to be at or above 1000 J/kg, along with long hodographs. Further, an increasing southerly low-level jet may aid storm longevity into the evening into western SD. ..Jewell.. 10/13/2025 $$  787 ACUS03 KWNS 132259 SWODY3 SPC AC 132257 Day 3 Convective Outlook CORR 1 NWS Storm Prediction Center Norman OK 0557 PM CDT Mon Oct 13 2025 Valid 151200Z - 161200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE CENTRAL HIGH PLAINS AND SOUTHERN ROCKIES... CORRECTED FOR IMPROPER LINE GROUPINGS ...SUMMARY... Isolated severe storms are possible on Wednesday across parts of the southern Rockies, and over the central High Plains. Areas of hail will be the primary risk, with sporadic strong gusts possible. ...Synopsis and Discussion... An upper low over UT will pivot northeastward toward the northern Rockies, with a belt of strong mid and high level flow moving across the Rockies and into the central and northern High Plains by Thursday morning. Low pressure will develop over eastern CO and WY during the afternoon, and will move into the Dakotas overnight. Surface moisture return will be limited due to a large area of high pressure over the Great Lakes, with poor trajectories extending south into the northern Gulf of America. However, cooling aloft with the upper trough and an existing plume of midlevel moisture will aid destabilization. By late afternoon, MUCAPE of 500-1000 J/kg is forecast over central NM, and from northeast CO into western NE. Early day precip may hamper destabilization in parts of the southern Rockies, but a few storms could produce marginal hail. Farther north into CO/WY/NE, isolated severe storms producing hail appear more likely as instability is more likely to be at or above 1000 J/kg, along with long hodographs. Further, an increasing southerly low-level jet may aid storm longevity into the evening into western SD. ..Jewell.. 10/13/2025 $$