Severe Storms

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1238 PM CDT Sat Aug 27 2022 Valid 281200Z - 291200Z ...NO CRITICAL AREAS... No changes have been made to the outlook. See the previous discussion below for more details. ..Dean.. 08/27/2022 .PREV DISCUSSION... /ISSUED 0145 AM CDT Sat Aug 27 2022/ ...Synopsis... A mid-level trough will eject into the northern Plains while upper ridging gradually builds over the Interior West tomorrow/Sunday. Despite the departing upper trough, up to 40 kts of 500 mb flow should still overspread a dry boundary layer across parts of the central into northern Rockies by afternoon peak heating. At least locally Elevated surface conditions should develop across the Snake River Plain in southern Idaho into eastern Wyoming, with windy, occasionally dry conditions also likely across Montana into the northern High Plains. Spotty fuel receptiveness or the lack of widespread overlapping favorable winds/RH suggest that fire weather highlights are not currently warranted. ...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 1228 PM CDT Sat Aug 27 2022 Valid 281200Z - 291200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF MINNESOTA AND WESTERN WISCONSIN... ...SUMMARY... Isolated to scattered severe thunderstorms should occur late Sunday afternoon and evening across parts of the northern/central Plains and Upper Midwest. Severe/damaging wind gusts and large hail should be the main threats, but a tornado or two also appear possible. ...Northern/Central Plains into the Upper Midwest... A well-defined shortwave trough will advance eastward across the northern Plains and Upper Midwest on Sunday. A 40-50 kt west-southwesterly jet will accompany this feature and overspread parts of the Upper Midwest through Sunday evening. The primary surface low should remain in central Canada, with a secondary low forecast to shift eastward across SD and western MN through the day. A cold front will sweep eastward across the Upper Midwest through the period. This front will serve as a focus for lift and related severe convective potential. A seasonably moist low-level airmass will likely be in place ahead of the front, with surface dewpoints generally in the mid 60s to low 70s. Diurnal heating of this airmass, along with the presence of steep mid-level lapse rates, should encourage the development of moderate to strong instability ahead of the front across MN/IA and eastern NE. The strongest instability should be present across southern/central MN and vicinity where better daytime heating is forecast. A low-level cap should inhibit convective development through much of the afternoon. But, robust thunderstorms should eventually initiate along/near the eastward-sweeping cold front across western/central MN by late Sunday afternoon. 30-40 kt of deep-layer shear will support updraft organization, with a mix of supercells and multicells possible initially. Both large hail and severe/damaging wind gusts may occur with this activity. A fairly quick transition to one or more bowing clusters should occur late Sunday afternoon/evening into eastern MN and western WI, with the wind threat becoming the primary severe concern. A tornado or two also appear possible through the early evening, as 0-1 km SRH appears sufficient for some low-level rotation with both cells and embedded QLCS circulations. The severe threat ahead of cold front appears a bit more uncertain and conditional with southward extent into IA and eastern NE. The better large-scale ascent associated with the upper trough will remain mostly to the north of these areas. Still, any thunderstorms that can form across this region Sunday afternoon/evening could become severe, with both an isolated large hail and damaging wind threat. Given the continued uncertainty with overall thunderstorm coverage across these areas, have opted to just expand the Marginal Risk for now, and keep greater severe probabilities focused in MN and western WI where convective coverage appears greater. ..Gleason.. 08/27/2022 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Sat Aug 27 2022 Valid 271630Z - 281200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF IA/MN/WI... ...SUMMARY... Severe thunderstorm potential appears most concentrated today over parts of Iowa, southeastern Minnesota and western Wisconsin. ...IA/MN/WI this afternoon/evening... A midlevel shortwave trough over the central NE/KS border will continue moving northeastward to western IA by this evening and the upper MS Valley overnight. Clouds and ongoing convection within a deep moisture plume over the central Plains will likewise spread northeastward through the day. Surface heating to the east of the thicker cloud band and relatively steep low-midlevel lapse rates will contribute to MLCAPE of 1500-2500 J/kg, and the likelihood of additional thunderstorm development this afternoon in the zone of differential heating from IA into southern MN (along and south of a warm front). Vertical shear profiles are forecast to be a bit disjointed with substantially backed/weaker flow in the mid levels across IA this afternoon. Low-level shear/clockwise hodograph curvature will be larger this afternoon/evening closer to the warm front across southeast MN/western WI, with a similar weakness in the midlevel flow. Thus, the environment favors a mixed/messy storm mode with clusters and some transient rotating updrafts, with a primary threat for damaging winds and isolated large hail given the moderately large buoyancy/precipitation loading and sufficiently steep low-midlevel lapse rates (DCAPE near 1000 J/kg). ...TX Panhandle into KS this afternoon/evening... Along the southern fringe of the residual monsoonal moisture plume and the ejecting midlevel trough over northern KS, differential heating and weak convergence along a lee trough will support scattered thunderstorm development later this afternoon. Midlevel lapse rates will not be steep, but surface heating/mixing will steepen low-level lapse rates, and westerly flow aloft will contribute to modest effective bulk shear of 25-30 kt. Somewhat organized cells/clusters will be capable of producing isolated strong-severe outflow gusts and marginally severe hail from mid afternoon into this evening. ...Southern MT and vicinity this afternoon/evening... Within the primary jet, an embedded speed max/shortwave trough over southern BC and WA will progress eastward to MT later this afternoon into tonight. An associated cold front will move into central MT by this evening, with strong surface heating and deep mixing in advance of the front. Some high-based convection is expected to form over the higher terrain of southern MT later this afternoon, and storms will spread eastward into this evening. Though low-level moisture and buoyancy will be limited, deep inverted-v profiles will support isolated strong-severe outflow gusts. ..Thompson/Karstens.. 08/27/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1126 AM CDT Sat Aug 27 2022 Valid 271700Z - 281200Z ...CRITICAL FIRE WEATHER AREA FOR FAR NORTHERN PORTIONS OF THE GREAT BASIN... No significant changes have been made to the Elevated and Critical areas. Critical conditions still appear most likely this afternoon from northeast NV/northwest UT into southern ID, with elevated to locally critical conditions surrounding this area from the northern Sierras into the north-central High Plains. Stronger winds are already noted across parts of southern ID this morning, while winds should increase elsewhere across the region in conjunction with continued heating/mixing and RH reductions. See the previous discussion below for more information. ..Dean.. 08/27/2022 .PREV DISCUSSION... /ISSUED 0144 AM CDT Sat Aug 27 2022/ ...Synopsis... A pronounced mid-level shortwave trough will progress across the northwestern U.S. today, promoting scattered high-based thunderstorms across the northern Rockies and dry/windy conditions across the northern Great Basin. Critically dry and windy surface conditions are most likely across northeast Nevada into southeast Idaho by late afternoon, though locally Critical conditions are also possible anywhere within the broader Elevated highlights, spanning from the northern Sierra to the northern High Plains. Elevated and Critical highlights have been withheld across southern into central Montana since recent rainfall has likely dampened fuels over several locales. The best chance for a couple of dry strikes as well as gusty, erratic thunderstorm winds would also be in central into southern Montana by late afternoon. Again, the lack of more widespread receptive fuels precludes dry thunderstorm highlights. ...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 1230 PM CDT Fri Aug 26 2022 Valid 271200Z - 281200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE SOUTHERN/CENTRAL PLAINS INTO THE UPPER MIDWEST... ...SUMMARY... Isolated strong to severe thunderstorms will be possible Saturday across the portions of the southern/central Plains into the Upper Midwest. Occasional hail and damaging winds should be the main threats. ...Southern/Central Plains into the Upper Midwest... A low-amplitude upper trough should advance east-northeastward across the northern Plains/Upper Midwest into Canada on Saturday. A separate shortwave trough over the central Plains should likewise develop northeastward into parts of the Upper Midwest through Saturday evening. A seasonably moist low-level airmass should be in place ahead of both of these features, with a weak front/surface trough across the Plains likely delimiting the western extent of any appreciable severe risk. The potential for organized severe thunderstorms across the Upper Midwest, especially MN and vicinity, still appears rather uncertain and conditional. The already modest large-scale ascent associated with the northern shortwave trough should be shifting into Canada through the day, leaving nebulous/unfocused forcing mechanisms for convective initiation. This uncertainty is evident in latest CAM guidance, which shows varying solutions regarding thunderstorm coverage and intensity across MN/WI through Saturday evening. Still, the presence of fairly steep mid-level lapse rates and diurnal heating should lead to a narrow corridor of at least moderate instability developing by late Saturday afternoon. Any thunderstorms that can develop across this region despite lingering weak convective inhibition would be capable of producing both isolated large hail and damaging winds, as effective bulk shear around 35 kt promotes some updraft organization. A better convective signal exists in guidance across IA and vicinity in association with the southern shortwave trough. Similar to locations farther north, moderate instability and sufficient deep-layer shear should support an isolated hail/wind threat with any robust thunderstorms that can develop across the warm sector Saturday afternoon and evening. Across the southern/central High Plains, isolated to scattered thunderstorms may develop along and east of a weak surface front/trough through Saturday afternoon. A deeply mixed boundary layer, with inverted-v type forecast soundings, should support some threat for isolated severe wind gusts. Deep-layer shear this far south appears marginal for any more than loose convective organization, but some hail may occur with initially more cellular convection before clustering occurs. ...Montana... A pronounced upper trough with attendant strong mid-level jet is forecast to move eastward across the Pacific Northwest and northern Rockies on Saturday. Very modest low-level moisture should be in place across MT ahead of this feature. While high-based thunderstorms should develop off the higher terrain and advance eastward across central/eastern MT through Saturday evening, it currently appears that instability will remain quite limited. Accordingly, have opted to not include low severe wind probabilities at this time. ..Gleason.. 08/26/2022 Read more

WW 0523 Status Updates
STATUS FOR WATCH 0523 HAS NOT BEEN ISSUED YET Read more

WW 523 SEVERE TSTM CT MA ME NH NY RI VT CW 261705Z - 270000Z
URGENT - IMMEDIATE BROADCAST REQUESTED Severe Thunderstorm Watch Number 523 NWS Storm Prediction Center Norman OK 105 PM EDT Fri Aug 26 2022 The NWS Storm Prediction Center has issued a * Severe Thunderstorm Watch for portions of Connecticut Massachusetts Extreme southern Maine Southern New Hampshire Extreme southeastern New York Rhode Island Extreme southern Vermont Coastal Waters * Effective this Friday afternoon and evening from 105 PM until 800 PM EDT. * Primary threats include... Scattered damaging wind gusts to 65 mph possible Isolated large hail events to 1 inch in diameter possible A tornado or two possible SUMMARY...Scattered thunderstorms are developing from eastern New York into southern New England and southern New Hampshire/Vermont. The storm environment will favor a mix of clusters/line segments and potentially some supercell structures, with a primary threat for damaging winds of 60-65 mph. The strongest storms will also be capable of producing isolated large hail near 1 inch in diameter, and an isolated/brief tornado may also occur with the most persistent supercells. The severe thunderstorm watch area is approximately along and 65 statute miles east and west of a line from 15 miles north of Laconia NH to 40 miles south southwest of Windsor Locks CT. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU3). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Severe Thunderstorm Watch means conditions are favorable for severe thunderstorms in and close to the watch area. Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible warnings. Severe thunderstorms can and occasionally do produce tornadoes. && AVIATION...A few severe thunderstorms with hail surface and aloft to 1 inch. Extreme turbulence and surface wind gusts to 55 knots. A few cumulonimbi with maximum tops to 500. Mean storm motion vector 25030. ...Thompson Read more

MD 1722 CONCERNING SEVERE POTENTIAL...WATCH POSSIBLE FOR FAR EASTERN NEW YORK INTO PARTS OF NEW ENGLAND
Mesoscale Discussion 1722 NWS Storm Prediction Center Norman OK 1125 AM CDT Fri Aug 26 2022 Areas affected...far eastern New York into parts of New England Concerning...Severe potential...Watch possible Valid 261625Z - 261830Z Probability of Watch Issuance...60 percent SUMMARY...Scattered strong storms will develop after 17Z, moving from eastern New York into parts of New England. A few damaging gusts are most likely, and a weak/brief tornado cannot be ruled out. DISCUSSION...Surface analysis shows a low developing over far eastern NY, and just south of an early-day cluster of thunderstorms which stretches into VT. Meanwhile, a diffuse warm front extends eastward toward far southern ME, though mixing may lead to a northward repositioning later today. Heating and advection of mid to upper 60s F dewpoints has led to an uncapped and unstable air mass, with CAPE presently in the 1000-2000 J/kg range. The strongest instability currently exists over southern New England where dewpoints are higher. Further, GPS PWAT sensors show a marked increase in overall moisture values through a deeper layer, approaching 1.50" near coastal CT. Convergence near the developing surface low and trailing surface trough and continued heating will lead to increasing storm coverage throughout the afternoon, progressing eastward. Deep-layer shear averaging near 35 kt, as well as veering winds with height suggest a several storms may be severe, producing a combination of damaging gusts and isolated hail. Steepening low-level lapse rates, and moist boundary layer, and weak SRH values could support a brief/weak tornado with the stronger isolated cells. ..Jewell/Thompson.. 08/26/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GYX...BOX...BTV...OKX...ALY... LAT...LON 41427435 42157405 43067354 43377319 43937184 43857078 43587026 42397060 41767172 41427217 41157331 41097393 41427435 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1116 AM CDT Fri Aug 26 2022 Valid 261700Z - 271200Z No changes have been made to the outlook. See the previous discussion below for more information. ..Dean.. 08/26/2022 .PREV DISCUSSION... /ISSUED 0103 AM CDT Fri Aug 26 2022/ ...Synopsis... Fire weather concerns will remain limited outside of the northern Great Basin today. An upper-level trough over the northern Rockies is forecast to gradually shift east into the Plains over the next 24 hours, which will support lee troughing along the northern to central High Plains with generally weakening flow over the West. Isolated dry thunderstorms are possible this afternoon across parts of MT under the upper wave, but the overall fire weather threat will remain limited. ...Northern Great Basin... Although stronger mid-level flow will gradually depart the region to the east through the day, continued zonal winds over the northern Sierra Nevada will promote sufficient downslope warming/drying for elevated wind/RH conditions across northern NV this afternoon. RH values, struggling to climb out of the teens/low 20s overnight, will likely fall into the teens (and perhaps single digits) this afternoon as winds increase to around 15 mph. Latest ERC estimates suggests fuels are adequately dry to support at least a low-end fire weather concern. ...Dry Thunderstorms... The 00 UTC TFX and OTX soundings sampled cold temperatures aloft under the northern Rockies upper-level trough. These thermodynamic conditions will persist for today and support modest, but sufficient, instability for convection by late afternoon despite decreasing PWAT values within the dry slot of the upper low. Forecast soundings suggest MUCAPE values may increase to around 250 J/kg with 2-3 km deep sub-cloud layers, favorable for dry lightning potential. Furthermore, storm motions near 20-30 knots may act to limit precipitation accumulations. While a few dry thunderstorms are possible from western to central MT this afternoon, fuel status is questionable after swaths of wetting rainfall over the past 24 hours (per latest MRMS estimates). ...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 1111 AM CDT Fri Aug 26 2022 Valid 261630Z - 271200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FOR PARTS OF NEW ENGLAND... ...SUMMARY... Isolated to widely scattered strong to severe thunderstorms are possible across the Northeast, as well as parts of the northern High Plains. ...Northeast this afternoon/evening... Embedded speed maxima will progress eastward from the lower Great Lakes to New England, within the southern portion of a broad belt of cyclonic mid-upper flow over southeast Canada. Likewise, a weak surface cyclone will move eastward from the Saint Lawrence Valley to ME by early tonight, as a trailing cold front moves southeastward across PA/NY/Southern New England. Scattered, slightly elevated thunderstorms are ongoing this morning over eastern NY in association with a lead shortwave trough. Surface heating and boundary-layer dewpoints in the mid 60s east of this convection and a pre-frontal trough will result in destabilization and will support surface-based thunderstorm development by early afternoon. Clusters and short line segments will subsequently spread eastward across New England in an environment of moderate buoyancy (MLCAPE of 1000-2000 J/kg) and vertical shear (effective bulk shear of 30-35 kt with modest hodograph length/low-level clockwise curvature). Occasional damaging gusts will be the main threat, though marginally severe hail and an isolated tornado will be possible. Isolated strong cells may occur farther west across NY this afternoon, near and east of the cold front, with more veered low-level flow and weaker vertical shear. ...Northern High Plains late this afternoon/evening... A weak midlevel trough will continue moving eastward over MT through this evening, and it will be preceded by a convectively-enhanced trough/MCV moving east-northeastward over SD. The southern fringe of the SD MCV will coincide with a corridor of boundary-layer dewpoints in the 60s along a warm front, but it is not clear that additional (surface-based storms) will form this afternoon across eastern SD. Otherwise, surface heating and residual 55-60 F dewpoints along a weak lee trough (in the zone of ascent downstream from the midlevel trough) will support afternoon/evening thunderstorm development from eastern MT into northeastern WY. Steepening low-midlevel lapse rates and deeper mixing across WY/MT will support the potential for isolated severe outflow winds/hail. Convection will tend to become elevated and will weaken with time while moving eastward into weakening buoyancy and larger convective inhibition across the Dakotas late this evening into tonight. ..Thompson/Jirak.. 08/26/2022 Read more

No watches are valid as of Thu Aug 25 17:47:01 UTC 2022.

No Mesoscale Discussions are in effect as of Thu Aug 25 17:47:01 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1230 PM CDT Thu Aug 25 2022 Valid 261200Z - 271200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF THE NORTHEAST... ...SUMMARY... Isolated to widely scattered strong to severe thunderstorms are possible across the Northeast States on Friday. ...Northeast... A broad mid-level trough will shift eastward across southeast Canada and into New England through daybreak Saturday. A mid-level vorticity maximum is forecast to move through the base of the trough and reach the St. Lawrence Valley by late afternoon. An associated surface low will migrate eastward across New England during the day. An attendant cold front will push eastward across New England. A mix of sun/clouds during the morning is expected with isolated to widely scattered showers/few thunderstorms expected closer to the Canadian border. A relatively moist boundary layer will destabilize through midday with surface dewpoints generally in the 60s deg F. Moderate buoyancy coupled with some enhancement to mid-level flow (30-40 kt at 500 mb) will contribute to the potential for storm organization. Scattered to numerous thunderstorms are forecast by the mid afternoon mainly in the form of multicellular clusters and bands of storms. A few transient supercells are possible and some risk for large hail and perhaps a tornado could develop with the most intense storms. This activity will likely diminish during the evening coincident with much of it pushing east of the coast and/or storms encountering convectively overturned air. ...Northern High Plains/Western Dakotas... A slow-moving upper low initially near the MT/Alberta border is expected to evolve into an open wave as it moves into the western Dakotas/southern Saskatchewan. A weak surface low will accompany this shortwave trough, moving ahead of it across southeast MT and into ND. A cluster of showers/storms will likely be ongoing across western SD early Friday morning. The associated cloud cover will probably temper diurnal heating and air mass destabilization over the Dakotas except for the far western part of SD. Models indicate isolated storms will develop by late afternoon in the vicinity of a moist axis extending from near the Black Hills northwestward into eastern MT. Isolated large hail/severe gusts are possible with the stronger storms. ..Smith.. 08/25/2022 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1141 AM CDT Thu Aug 25 2022 Valid 261200Z - 271200Z ...NO CRITICAL AREAS... The previous forecast reasoning (see below) remains on track, and no changes were made with this update. ..Weinman.. 08/25/2022 .PREV DISCUSSION... /ISSUED 0143 AM CDT Thu Aug 25 2022/ ...Synopsis... Mid-level flow is expected to strengthen across the northwestern U.S. as a more pronounced mid-level trough overspreads the Pacific Northwest tomorrow/Friday. While scattered thunderstorms may support a dry strike or two in a locally more receptive fuel bed across the northern Rockies, a slightly more appreciable fire-weather spread threat may exist across the northern Great Basin closer to the mid-level trough. The stronger flow aloft will overspread a dry boundary layer to the lee of the Cascades southeastward into the northern Great Basin, promoting at least locally Elevated dry/windy surface conditions during the afternoon. Highlights have been withheld this outlook given the more localized conditions overlapping spotty fuels. Surface lee troughing will also increase across the central Plains, along with strong southerly surface flow, encouraging locally to widespread Elevated dry and windy conditions. However, recent appreciable rainfall accumulations, especially across central Nebraska into the Dakotas, has likely dampened fuels to a degree, precluding fire weather highlights this outlook. ...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 1141 AM CDT Thu Aug 25 2022 Valid 251700Z - 261200Z ...NO CRITICAL AREAS... There are no changes to the forecast. For details, see the previous discussion below. ..Weinman.. 08/25/2022 .PREV DISCUSSION... /ISSUED 0125 AM CDT Thu Aug 25 2022/ ...Synopsis... Broad cyclonic upper flow will prevail across the eastern U.S. while multiple mid-level impulses will traverse the Northwest into the central Plains today. Scattered thunderstorms are expected to develop amid a modestly buoyant airmass across portions of the northern Rockies. A few of the thunderstorms may be dry initially, before becoming a more wet/dry mix. Fuels, however, are receptive to wildfire spread on a spotty basis. As such, sparse dry strikes into patchy receptive fuels or gusty, erratic winds emanating from storms may support very localized wildfire-spread potential. Locally dry and windy conditions are also possible across parts of the northern Great Basin in association with the passage of a mid-level impulse. ...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 1120 AM CDT Thu Aug 25 2022 Valid 251630Z - 261200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER WESTERN MONTANA AND ACROSS PORTIONS OF THE NORTH-CENTRAL HIGH PLAINS... ...SUMMARY... Isolated severe hail and thunderstorm gusts will be possible across portions of western Montana and the north-central High Plains today. ...Western MT... Slow-moving closed upper low over near the international border in the vicinity of northern ID will begin to move slowly east late today. Diurnal heating of initially 50s surface dew points will result in a deep mixed layer, and steep midlevel lapse rates will contribute to 1000-1500 J/kg MLCAPE this afternoon. Although winds throughout the cloud-bearing layer will be generally modest (30 kts or less), veering low/midlevel flow will contribute to 30-35 kts of effective shear. Widely scattered to scattered thunderstorm development is expected this afternoon across western MT, with multicell/supercell modes possible. Deep mixed layer will result in a risk for isolated severe wind gusts, and large hail will be possible with a few stronger updrafts/supercell structures. ...North-Central High Plains... Midlevel perturbation currently over western WY will continue east, with a region of ascent favorably timed to develop over the Big Horn/Black Hills region during the mid/late afternoon. Despite ongoing cloud cover, heating of mid/upper 50s surface dew points beneath reasonably steep midlevel lapse rates should result in pockets of MLCAPE of 1000-1500 J/kg. Modest midlevel west/northwest flow will contribute to around 30 kts of effective shear which will favor a mixed multicell/transient supercell mode. Isolated stronger storms will be capable of strong/damaging gusts and hail through early evening. ..Bunting/Wendt.. 08/25/2022 Read more

No watches are valid as of Wed Aug 24 17:48:02 UTC 2022.

No Mesoscale Discussions are in effect as of Wed Aug 24 17:48:02 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1222 PM CDT Wed Aug 24 2022 Valid 251200Z - 261200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not forecast across the contiguous United States on Thursday. ...Northern Rockies/Northern High Plains... A slow-moving and weakening mid-level low will move east across the northern Rockies into the northern High Plains. Widely scattered to scattered diurnal thunderstorms are forecast to develop during the afternoon over the higher terrain of western into southern MT and near the Big Horns/Black Hills. Models continue to indicate that heating will be tempered in some areas due to partial cloud cover. However, steepening low-level lapse rates and large directional shear contributing to modest deep-layer shear, will support intermittently organized multicells. Given the marginal character of the potential storm intensity, will defer the highlighting of low wind probabilities for the time being. ..Mid MS Valley... A cold front, associated with a shortwave trough moving through the Upper Great Lakes, is expected to move southward through the Mid MS Valley Thursday afternoon and evening. Dewpoints will likely be in the upper 60s and temperatures in the mid 80s ahead of the front, resulting in moderate buoyancy. Isolated to widely scattered thunderstorms are anticipated across the region near the front. A few stronger updrafts could develop, but weak vertical shear will limit storm intensity. ...Elsewhere... Thunderstorms are also possible within the monsoonal moisture still in place across the Southwest and central Rockies, and in the vicinity of subtle upper low and associated surface low over the Southeast and FL. In each of these regions, weak vertical shear should keep the severe threat low. ..Smith.. 08/24/2022 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1129 AM CDT Wed Aug 24 2022 Valid 251200Z - 261200Z ...NO CRITICAL AREAS... The forecast remains on track, and no changes were made with this update. For details, see the previous discussion below. ..Weinman.. 08/24/2022 .PREV DISCUSSION... /ISSUED 0153 AM CDT Wed Aug 24 2022/ ...Synopsis... A mid-level trough will meander across the northern Rockies tomorrow/Thursday, supporting another day of scattered thunderstorms (a couple of which may be dry) by afternoon. Similar to Day 1, fuels are expected to remain receptive to fire spread on a spotty basis. Given recent rainfall accumulations as well as the potential for appreciable accumulations on Day 1, fuel receptiveness to wildfire spread will likely remain modest, precluding dry thunderstorm highlights this outlook. Also like Day 1, locally Elevated dry and windy conditions may occur in terrain-favoring areas of the northern Great Basin by afternoon. ...Please see www.spc.noaa.gov/fire for graphic product... Read more