Severe Storms

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Mon Oct 24 2022 Valid 241630Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE SOUTHERN PLAINS/ARKLATEX... ...SUMMARY... Severe thunderstorms are possible from central Texas and eastern Oklahoma to the ArkLaTex, east Texas, far western Louisiana and the middle/upper Texas Coast through tonight. Damaging gusts will be the main hazard with these storms, although a couple of tornadoes are also possible. ...Southern Plains/ArkLaTex... A semi-organized but not overly intense squall line continues to progress eastward from near/east of I-35 across east-central Oklahoma and North Texas. Locally severe storms will remain a possibility with this convective line in the presence of strong/largely unidirectional deep-layer shear and modest lapse rates/buoyancy. Thinking remains that this regional severe threat this afternoon could remain a bit isolated/episodic across eastern Oklahoma/north Texas. A somewhat more organized/sustained severe risk should evolve by early evening, initially across central Texas and into eastern/south-central Texas tonight. This will be as the base of the southern Rockies upper trough ejects eastward and trends toward a more neutral tilt, with surface wave development/cyclogenesis expected from northwest Texas late this afternoon east-northeastward along the Red River vicinity and Ozarks late tonight. This scenario should allow for the southwest flank of the residual squall line/outflow to reinvigorate across central/east-central Texas by early evening, and for new development to occur near the east/southeastward-accelerating cold front tonight. Steady low-level moistening and modest cooling aloft could support upwards of 750-1250 J/kg MLCAPE this evening across central/east Texas. Increasingly large/modestly curved hodographs may yield the possibility of a few semi-discrete supercells ahead of or in the early developmental stages of the squall line, with evolving bowing segments otherwise likely. A couple of tornadoes may occur aside from possible wind damage. Given the large-scale trends and expected persistence of weak warm-sector buoyancy, at least some severe risk is expected to persist eastward through the late night/early Tuesday morning across far east/southeast Texas into Louisiana/possibly southern Arkansas, even if on just an isolated/marginal basis overnight. ...Northwest Texas/Low Rolling Plains... A spatially narrow/residual corridor of low-level moisture and buoyancy may be sufficient for the development of some low-topped stronger storms late this afternoon/early evening as lapse rates steepen. A few instances of strong thunderstorm winds and/or hail could occur. ..Guyer/Kerr.. 10/24/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1021 AM CDT Mon Oct 24 2022 Valid 241700Z - 251200Z ...NO CRITICAL AREAS... No changes to the previous outlook. ..Wendt.. 10/24/2022 .PREV DISCUSSION... /ISSUED 0107 AM CDT Mon Oct 24 2022/ ...Synopsis... A potent mid-level trough and associated surface cold front will progress across the Plains states today, preceded by widespread showers and thunderstorms. Appreciable rainfall accumulations should limit significant, widespread wildfire-spread concerns. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Sun Oct 23 17:49:02 UTC 2022.

No Mesoscale Discussions are in effect as of Sun Oct 23 17:49:02 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1219 PM CDT Sun Oct 23 2022 Valid 241200Z - 251200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL TX EASTWARD TO THE ARKLATEX...EAST TX/FAR WESTERN LA...AND MIDDLE/UPPER TX COASTS... ...SUMMARY... Severe thunderstorms are possible from central Texas eastward to the Arklatex, east Texas, far western Louisiana and middle/upper Texas Coast Monday evening and overnight. Damaging gusts will be the main hazard with these storms, though a tornado or two is also possible. ...Synopsis... A complex upper pattern evolution is anticipated on Monday as a large-scale upper trough gradually moves eastward across the Plains. Two shortwave troughs embedded within the larger-scale trough will focus severe thunderstorm potential on Monday. The first shortwave trough will be located over the northern Plains early in the period, and the other over the Southwest. The northern Plains shortwave is expected to quickly lift northeast during the morning, while the Southwest shortwave moves eastward from the Four Corners and into the southern Plains during the afternoon and into the overnight hours. Another weak shortwave impulse over northern Mexico will precede the Southwest shortwave across TX, while the remnants of Hurricane Roslyn move quickly northeastward along the TX Coast into the Lower MS Valley. An occluded surface low will be located over eastern ND Monday morning, with an occluded front extending southeastward to a triple point over central MN. A cold front will then extend southwestward from this triple point through the Lower MO Valley into central OK. The front is expected to progress gradually eastward throughout day, with the exception being the southern extent of the front in TX, which will only make minor eastward progress until Monday evening when stronger surface cyclogenesis occurs along the Red River. This surface low will then shift east/northeast into AR overnight, as the shortwave upper trough ejects eastward and the front surges eastward toward the Sabine Valley and TX coast. ...Northwest MN... Thunderstorms will likely be ongoing early Monday morning near the surface low and along the northeastward advancing front. Forecast guidance suggest MLCAPE as high as 750 J/kg will be present amid strong vertical shear. Fast storm motion coupled with strong low/mid-level flow and modest instability could support isolated strong gusts for a couple hours Monday morning before convection lifts north into Manitoba/western Ontario. ...Southern Plains Vicinity... Showers and thunderstorms will be ongoing in the vicinity of the front from southeast KS across central OK and into southwest TX. Buoyancy will be tempered by relatively warm mid-level temperatures but moderate mid-level flow with a 40+ kt southerly low-level jet could still result in a few updrafts capable of hail and/or strong downdrafts. The front will progress eastward across KS/MO/OK during through the afternoon/evening, but become more diffuse across TX as a surface low develops across western North TX during the afternoon. The surface low should develop eastward along the Red River and into AR during the evening and overnight hours, allowing the TX portion of the cold front to surge eastward while the upper shortwave trough ejects eastward into the Plains. This will support additional thunderstorm development along the front as large-scale ascent increases within a moist and moderately unstable airmass. Linear segments will support mainly damaging gusts. However, enlarged and favorably curved low-level hodograph suggest some tornado potential will exist near the front and surface low, where low-level vorticity will be maximized. ..Leitman.. 10/23/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1146 AM CDT Sun Oct 23 2022 Valid 231700Z - 241200Z ...CRITICAL FIRE WEATHER AREA FOR PARTS OF THE CENTRAL PLAINS... No changes to the ongoing forecast. ..Wendt.. 10/23/2022 .PREV DISCUSSION... /ISSUED 0159 AM CDT Sun Oct 23 2022/ ...Synopsis... In the mid-levels, a strong western US trough will intensify further as an 80-90 kt mid-level jet ejects eastward across the southern and central Rockies over the Plains. The strong mid-level flow will aid in the development of a sub-990 mb lee low and very strong surface wind fields over much of the central US. With widespread drought across the Plains, the strong winds and dry/warm conditions will support widespread critical fire weather concerns. ...Central and southern Plains... As the strong area of low pressure continues to deepen and eject northeastward, low-level southwesterly pressure gradients will intensify over much of the Plains. A broad area of sustained 25-40 mph winds, with gusts upwards of 50 mph, will be possible through the afternoon. Coincident with diurnal heating, areas of low to critical RH (15-30%) are expected through the afternoon. RH will be lowest across the High Plains west of the lee trough, with values near or above 30% likely farther east. In addition, fuels remain highly receptive to fire spread due to ongoing drought over all of the Plains with ERCs in the 90th+ percentile. The overlap of highly receptive fuels, strong winds and lower RH lends high confidence to sustained elevated and some critical fire weather conditions this afternoon. A few hours of localized extremely critical conditions will also be possible mainly across portions of western KS and far eastern CO where the strongest winds are expected. While mid-level cloud cover may reduce afternoon mixing, strong downslope flow and warm temperatures may still support a few pockets of sub 10% RH and wind gusts greater than 50 mph. The favorable meteorological and fuel conditions may support rapid wind-driven fire spread. ...California... Along the backside of the trough, strong mid-level flow will support gusty surface winds through the Central Valley and coastal mountains. While fuels remain spotty, a few hours of lower humidity and gusty winds may support locally elevated fire weather conditions. Confidence remains too low to introduce areas of concern. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sun Oct 23 2022 Valid 231630Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE CENTRAL PLAINS AND UPPER MIDWEST... ...SUMMARY... Thunderstorms capable of severe wind gusts and hail are possible from parts of the central Plains to Upper Midwest late this afternoon and tonight. ...Central Plains to Upper Midwest... A prominent western states upper trough continues to evolve/amplify over the Rockies and Four Corners, with a strong mid/upper-level jet expected to develop northeastward from Arizona/New Mexico across the central Plains toward the Upper Midwest. Lee-side cyclogenesis will continue to occur initially across the central Plains while transitioning northeastward toward the eastern Dakotas tonight as a cold front begins to accelerate eastward across the central Plains/Upper Midwest. Modest autumnal low-level moisture will continue to stream northward and become increasing established within the warm sector ahead of the cold front, and more so, the preceding dryline across the central/southern Plains, although mixing (and some possible surface dewpoint reduction) will also occur as the boundary layer warms through peak heating. Isolated to widely scattered thunderstorms are expected along/ahead of the combined cold front/dryline as early as late afternoon, but more so toward/after sunset. Any surface-based thunderstorms will have the potential for isolated severe hail and wind gusts, given supercell-favorable vertical shear and fast storm motion atop a residually well-mixed warm-sector boundary layer. An increasing low-level jet (50-70 kt after 00Z) will enlarge low-level hodographs, with 30-35 kt shear-vector magnitudes in the effective-inflow layer, and effective SRH potentially in the 300-500 m2/s2 range. ...West-central/northwest Texas to southwest Oklahoma... Widely scattered to scattered thunderstorms are possible late tonight across this region, as the combined fronts overtake the dryline and impinge on increasing deep-layer moisture. Neither middle nor upper-level lapse rates are expected to be particularly steep. However, with increasing low-level moisture, and strengthening deep shear, an organizing band of convection may strengthen enough to produce a few embedded storms capable of isolated hail and/or wind gusts near severe limits. ..Guyer/Kerr.. 10/23/2022 Read more

No watches are valid as of Sat Oct 22 17:45:02 UTC 2022.

No Mesoscale Discussions are in effect as of Sat Oct 22 17:45:02 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1234 PM CDT Sat Oct 22 2022 Valid 231200Z - 241200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL PLAINS TO SOUTHWEST MINNESOTA... ...SUMMARY... Severe thunderstorms capable of damaging gusts and hail are possible from the central Plains into the Upper Midwest Sunday evening into early Monday morning. Additional isolated severe thunderstorms may produce strong gusts and hail across parts of the southern Plains early Monday morning. ...Central Plains...Lower/Mid MO Valley...Upper Midwest... A strong large-scale upper trough will shift east from the western U.S. toward the Plains on Sunday. An embedded shortwave trough within this larger-scale flow will focus thunderstorm potential across parts of the central Plains into the Upper Midwest. An intense 50-70 kt southwesterly 850-700 mb low-level jet oriented from the southern Plains to southwest IA during the afternoon will spread northeast toward the Upper MS Valley/Great Lakes vicinity overnight. Surface cyclogenesis will occur as a low lifts north/northeast from NE toward northwest MN/northeast ND by Monday morning. Moderate southerly low-level flow will transport Gulf moisture northward across the south-central states into the Upper Midwest, where an antecedent dry airmass will be in place early Sunday. Forecast guidance continues to vary regarding surface dewpoints, with differences of around 5-8 deg F by late afternoon/evening. There is also disparity in timing/progression of the surface cold front, lending to further uncertainty regarding where convective initiation will occur. Despite questionable moisture quality and frontal position, conditional severe potential will exist from central/eastern KS into MN, aided by strong large-scale ascent associated with the ejecting trough and contributing surface cold front, coupled with robust vertical shear. Given the expected intense background flow/low-level jet, strong gusts will be possible with even modest convection, but especially so with any clusters/line segments that may develop. ...Southern Plains... A southern stream shortwave moving across western Mexico will merge with the base of the large-scale trough approaching the southern Rockies. Increasing midlevel moisture and low-level warm advection ahead of the surface front draped across western TX will support late-period thunderstorm development across parts of northwest TX into southern OK. MLCAPE increasing to 500-1000 J/kg coupled with effective shear magnitudes greater than 35 kt will support organized updrafts. Isolated strong gusts and small hail could accompany this activity early Monday morning, and a Marginal risk has been included. ..Leitman.. 10/22/2022 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Sat Oct 22 2022 Valid 221630Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected today and tonight. ...Discussion... Significant amplification of an upper-level trough will occur over the Great Basin/Rockies through tonight. Despite limited autumnal moisture, ample forcing for ascent and steepening lapse rates will lead to isolated thunderstorms, particularly across parts of the Great Basin and Four Corners states later this afternoon and evening. While some stronger convectively related wind gusts could occur, the potential for severe thunderstorms will remain low. Isolated thunderstorms will also remain possible today along the coastal Pacific Northwest, and could also occur late tonight across coastal North Carolina (but more so in the offshore Atlantic). ..Guyer/Dean.. 10/22/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1049 AM CDT Sat Oct 22 2022 Valid 221700Z - 231200Z A few minor adjustments to the outlook in Oklahoma and western North Texas based on the latest guidance and Fridays fire activity. The forecast elsewhere remains unchanged. ..Wendt.. 10/22/2022 .PREV DISCUSSION... /ISSUED 1214 AM CDT Sat Oct 22 2022/ ...Synopsis... Ahead of a deepening area of low pressure across the western US, strong southwesterly surface winds are expected across the Central and High Plains. Given the increase in winds, dry air mass, and receptive fuels, an area of Elevated fire weather conditions is expected on Saturday. ...Central and High Plains... Southwesterly winds around 15-20 mph along with afternoon minimum relative humidity around 15-20 percent will be possible across portions of western Nebraska southward into eastern Colorado and southern Kansas/west-central Oklahoma. Fuels across the aforementioned region are receptive, with ERCs above the 95th percentile. Similar weather conditions can be expected across the Texas Panhandle, but recent rainfall has led to improvement in fuels and precludes the need for an Elevated area. ...Southern California and Southern Nevada... Recent model runs indicate that sustained winds could approach as high as 20-30 mph across portions of the low deserts of southern California and southern Nevada. Relative humidity will be marginal with a few stations near-critical briefly. Due to the localized threat area and lack of more robust fuels, an Elevated or Critical area was not supported. ...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 0108 PM CDT Fri Oct 21 2022 Valid 221200Z - 231200Z Only minor changes to the ongoing forecast. While winds will be similar to Friday in the southern Plains, RH in parts of Oklahoma into Kansas could be a touch higher. Elevated conditions will be spotty in eastern Colorado. The greatest risk for sustained elevated conditions will be within terrain-favored regions near the Divide/foothills. Locally critical conditions are most probable in the Nebraska Panhandle. This area will be near the deepening surface cyclone and moderate mid-level winds. Such conditions still appear too brief for critical highlights. ..Wendt.. 10/21/2022 .PREV DISCUSSION... /ISSUED 0201 AM CDT Fri Oct 21 2022/ ...Synopsis... Ahead of a deepening trough across the Pacific Northwest, upper-level flow will increase across the western US with strengthening southwesterly surface gradients across the Central and High Plains. Gulf moisture will make a limited return across eastern Oklahoma and Nebraska, but remain largely within the Mississippi and Ohio River Valleys. A broad Elevated area has been introduced across portions of the Central and High Plains, where dry conditions will prevail along with strong gusty winds and receptive fuels. ...Central and High Plains... Southwest winds at 15-20 mph and minimum relative humidity around 15-20 percent (locally as low as 10 percent) are possible Saturday. This will support an Elevated delineation extending from portions of western Nebraska southward into eastern Colorado and southern Kansas/west-central Oklahoma. Winds may be marginal across portions of this region along with some potential for mid-level cloud cover in central Oklahoma. Fuels continue to be very dry, with ERCs above the 95 percentile, supporting the Elevated risk even with the potential for marginal winds (mainly across western Colorado and Kansas). ...Southern California and Nevada... Strong westerly downslope flow across portions of southern California and Nevada may lead to areas of elevated fire concern on Saturday. Due to the localized threat area and lack of more robust fuels, an Elevated area was not supported. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Fri Oct 21 18:10:02 UTC 2022.

No Mesoscale Discussions are in effect as of Fri Oct 21 18:10:02 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1147 AM CDT Fri Oct 21 2022 Valid 221200Z - 231200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not expected on Saturday. ...Synopsis... An upper trough is forecast to amplify over the West on Saturday. As this occurs, a persistent upper low offshore of Baja California will begin moving eastward. Across the East, a weak upper low is forecast to drift northward offshore of the GA/Carolina coast, while weak ridging develops upstream of this feature across the Southeast. Southerly low-level flow will increase across much of the central U.S. as a surface cyclone gradually deepens over the northern High Plains. Modest low-level moisture return is expected across parts of the central/southern Plains, but instability is expected to remain minimal across this region through the period. Low/mid-level moistening may support isolated thunderstorm development across parts of AZ/NM. Coverage remains uncertain across this region, but deep-layer shear will be sufficient to support a strong storm or two if deep convection can be sustained. Elsewhere, a broad general thunderstorm area has been maintained from the Pacific Northwest into parts of the central Rockies, where steep midlevel lapse rates and weak buoyancy may support isolated lightning flashes embedded within larger precipitation areas. To the east, weak convection may spread into coastal NC late Saturday night as the upper low drifts northward, with potential for sporadic lightning flashes into early Sunday morning. ..Dean.. 10/21/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1137 AM CDT Fri Oct 21 2022 Valid 211700Z - 221200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHERN WYOMING... ...CRITICAL FIRE WEATHER AREA FOR NORTHERN NEVADA... No changes to the ongoing forecast. Locally elevated conditions remain possible in portions of the Midwest where conditions will be breezy but RH will only be marginally critical in a limited area. ..Wendt.. 10/21/2022 .PREV DISCUSSION... /ISSUED 1236 AM CDT Fri Oct 21 2022/ ...Synopsis... A more progressive pattern develops on Friday as ridging across the western US weakens and a trough deepens across the northern Pacific. Associated with the deepening trough, strong westerly flow aloft will overspread areas from the northern Great Basin into the northern Rockies with continued dry conditions. Critical fire weather conditions are expected across northern Nevada and in southern Wyoming. ...Central and Southern Wyoming... Dry downslope flow across south-central Wyoming will support sustained surface winds at 20-25 mph and afternoon relative humidity around 15-20 percent. Locally stronger winds up to 30+ mph may support pockets of extreme fire weather conditions. As these winds look to be fairly localized, a Critical delineation covers the threat well. ...Northern Great Basin... Across northern Nevada, sustained winds around 15-20 mph, relative humidity around 10-15 percent, and ERCs above the 95th percentile will support a Critical delineation. While winds may be marginal in a few areas, ERCs are well above seasonal averages with below normal rainfall in the last month. ...Central Plains... Sustained winds around 15-20 mph and minimum relative humidity around 15-20 percent will be possible across portions of central Oklahoma into southeastern Kansas. Fuels are moderately receptive across much of Oklahoma, worsening into southeastern Kansas. Higher relative humidity around 20-25 percent will be possible across southeastern Kansas. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Oct 21 2022 Valid 211630Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible near coastal eastern Florida. ...Discussion... The potential for thunderstorms will continue near the east coast of the Florida Peninsula, although the majority of deeper convection should remain offshore. Relatively moist marine air near the coast and relatively cool mid-level temperatures in association with a Southeast States upper low will support this near-coastal thunderstorm potential. Elsewhere, a few lightning flashes could occur across the coastal Pacific Northwest tonight in association with steepening lapse rates via an amplifying upper-level trough. However, overall thunderstorm probabilities/coverage are expected to remain low (below 10 percent). ..Guyer/Squitieri.. 10/21/2022 Read more

No watches are valid as of Thu Oct 20 17:43:01 UTC 2022.

No Mesoscale Discussions are in effect as of Thu Oct 20 17:43:01 UTC 2022.