Severe Storms

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1222 PM CDT Sun Oct 02 2022 Valid 031200Z - 041200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Organized severe thunderstorms are not forecast for Monday across the contiguous United States. ...Synopsis... A weak mid- to upper-level trough will migrate slowly east across MT/WY into the Dakotas through Tuesday morning. A surface trough will extend from the Dakotas southward into the central High Plains while high pressure influences weather conditions across much of the central and eastern U.S. Near the surface trough, a narrow plume of modest moisture (surface dewpoints in the 40s and lower 50s) and heating will yield MLCAPE around 750 J/kg from SD into NE along the wind shift, beneath relatively weak midlevel southwesterlies below 30 kt. Scattered convection is likely to form off the Front Range, producing small hail and locally gusty winds. Given the relatively dry air mass and weak low-level winds, it appears convection will be sub severe. Farther southwest in the Four Corners, primarily diurnal storm activity will result in widely scattered to scattered storms during the afternoon to early evening. ..Smith.. 10/02/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1138 AM CDT Sun Oct 02 2022 Valid 021700Z - 031200Z Higher than expected humidity recoveries developed overnight across northern portions of the Elevated area across central Nebraska and northwestern Kansas. Higher RH and lingering clouds may limit some warming and drying through the afternoon. However, gusty southerly winds and very dry fuels may still support a few hours of locally elevated fire weather conditions across portions of the central Plains. The previous outlook remains valid with no appreciable changes. See the previous discussion. ..Lyons.. 10/02/2022 .PREV DISCUSSION... /ISSUED 0117 AM CDT Sun Oct 02 2022/ ...Synopsis... An upper low will impinge on the northern High Plains while upper ridging remains in place across the Plains States today. Surface lee troughing will encourage dry southerly flow across the Plains with the approaching of the upper low. Latest guidance consensus depicts Elevated overlapping sustained surface winds and RH for at least a few hours this afternoon across the central Plains. Elevated highlights have been introduced where fuels are at least modestly receptive to fire spread and are devoid of recent appreciable rainfall accumulations. ...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 1138 AM CDT Sun Oct 02 2022 Valid 021700Z - 031200Z Higher than expected humidity recoveries developed overnight across northern portions of the Elevated area across central Nebraska and northwestern Kansas. Higher RH and lingering clouds may limit some warming and drying through the afternoon. However, gusty southerly winds and very dry fuels may still support a few hours of locally elevated fire weather conditions across portions of the central Plains. The previous outlook remains valid with no appreciable changes. See the previous discussion. ..Lyons.. 10/02/2022 .PREV DISCUSSION... /ISSUED 0117 AM CDT Sun Oct 02 2022/ ...Synopsis... An upper low will impinge on the northern High Plains while upper ridging remains in place across the Plains States today. Surface lee troughing will encourage dry southerly flow across the Plains with the approaching of the upper low. Latest guidance consensus depicts Elevated overlapping sustained surface winds and RH for at least a few hours this afternoon across the central Plains. Elevated highlights have been introduced where fuels are at least modestly receptive to fire spread and are devoid of recent appreciable rainfall accumulations. ...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 1125 AM CDT Sun Oct 02 2022 Valid 021630Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM UTAH/FOUR CORNERS TO THE NORTHERN HIGH PLAINS... ...SUMMARY... Isolated severe hail and wind-producing storms may occur from Utah northeastward into the northern High Plains this afternoon and early evening. ...Utah/Four Corners to northern High Plains... A closed upper low centered over southern Montana will gradually open and spread slowly eastward, with a southern peripheral belt of moderately strong westerlies over the Great Basin and central Rockies. A few areas of showers/thunderstorms are ongoing early today, but in general, relatively cloud-free skies will allow for ample early autumn heating and related boundary layer destabilization this afternoon from southern/eastern Utah into southern/eastern Wyoming and the nearby High Plains areas including the Black Hills vicinity. Destabilizing boundary layer aside, the right-entrance region of a cyclonically curved mid-level jet will influence thunderstorm development particularly across southern/eastern Utah. The strength of mid/high-level west-southwesterly winds (35+ kt effective shear) could yield some high-based supercells aside from sustained multicells. Severe hail and severe-caliber winds gusts can be expected on an isolated basis. Other storms will also increase over the mountains/interior Wyoming and move into eastern Wyoming/western South Dakota vicinity later this afternoon. Meager low-level moisture will limit CAPE and overall updraft strength. However, moderately strong winds aloft and steep lapse rates will promote gusty winds and perhaps some hail in the strongest storms. ..Guyer/Wendt.. 10/02/2022 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1125 AM CDT Sun Oct 02 2022 Valid 021630Z - 031200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM UTAH/FOUR CORNERS TO THE NORTHERN HIGH PLAINS... ...SUMMARY... Isolated severe hail and wind-producing storms may occur from Utah northeastward into the northern High Plains this afternoon and early evening. ...Utah/Four Corners to northern High Plains... A closed upper low centered over southern Montana will gradually open and spread slowly eastward, with a southern peripheral belt of moderately strong westerlies over the Great Basin and central Rockies. A few areas of showers/thunderstorms are ongoing early today, but in general, relatively cloud-free skies will allow for ample early autumn heating and related boundary layer destabilization this afternoon from southern/eastern Utah into southern/eastern Wyoming and the nearby High Plains areas including the Black Hills vicinity. Destabilizing boundary layer aside, the right-entrance region of a cyclonically curved mid-level jet will influence thunderstorm development particularly across southern/eastern Utah. The strength of mid/high-level west-southwesterly winds (35+ kt effective shear) could yield some high-based supercells aside from sustained multicells. Severe hail and severe-caliber winds gusts can be expected on an isolated basis. Other storms will also increase over the mountains/interior Wyoming and move into eastern Wyoming/western South Dakota vicinity later this afternoon. Meager low-level moisture will limit CAPE and overall updraft strength. However, moderately strong winds aloft and steep lapse rates will promote gusty winds and perhaps some hail in the strongest storms. ..Guyer/Wendt.. 10/02/2022 Read more

No watches are valid as of Sat Oct 1 17:47:02 UTC 2022.

No Mesoscale Discussions are in effect as of Sat Oct 1 17:47:02 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1217 PM CDT Sat Oct 01 2022 Valid 021200Z - 031200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated strong storms with gusty winds and small hail may occur from eastern Utah northeast into the central High Plains on Sunday, however the overall severe risk appears low. ...Synopsis... An upper-level low over the northern Rockies will lift slowly northeast Sunday while an upper trough persists along the vicinity of the east coast. In between, a ridge of high pressure will extend from the southern Plains north into the upper Midwest. Over much of the CONUS east of the Rockies, low-level moisture/instability will be lacking and thunderstorms are not expected. Available moisture coupled with diurnal heating will result in sufficient instability for thunderstorm development from Arizona northeast through the Rockies and central/northern high Plains. Cool mid-level temperatures and modestly enhanced flow associated with the upper low may result in a few stronger storms across eastern UT and western CO, and also across the central high Plains as an embedded impulse within southwesterly mid-level flow lifts northeast. Small hail and gusty winds will be possible, however weak buoyancy should limit the overall severe potential. ..Bunting.. 10/01/2022 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1109 AM CDT Sat Oct 01 2022 Valid 011630Z - 021200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE FOUR CORNERS AREA... ...SUMMARY... Isolated damaging wind gusts and hail may accompany the stronger storms across parts of the Four Corners today, including portions of southern Utah into Colorado. ...Four Corners to eastern Colorado/Wyoming... Within an amplified large-scale pattern over CONUS, a prominent closed upper low over the northern Intermountain region will tend to gradually weaken and spread slowly northward through tonight. Within its base, a belt of moderately strong cyclonic flow aloft will persist over the region. An east-northeastward pivoting vort max appears to be influencing scattered showers/thunderstorms early today across eastern Utah/western Colorado. Additional storms are expected to redevelop later this afternoon near the front across southern Utah into southwest Colorado. Despite dewpoints only in the 40s F, strong heating and steep low/mid-level lapse rates will result in weak but sufficient CAPE for a few high-based storms capable of gusty/locally damaging winds and perhaps hail. This activity will spread eastward into western Colorado later today before weakening after sunset. Farther east, a few stronger storms may also occur or persist into eastern portions of Wyoming/Colorado this afternoon. Sufficient low-level moisture and buoyancy should exist for some stronger/sustained updrafts, although modest mid-level lapse rates by Front Range/High Plains standards may temper updraft intensity a bit. While some gusty winds/small hail could occur with these mostly linear clusters, organized/sustained severe storms are not currently expected. ..Guyer/Moore.. 10/01/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1051 AM CDT Sat Oct 01 2022 Valid 011700Z - 021200Z ...NO CRITICAL AREAS... Brief elevated fire weather conditions are possible east of a lee trough across portions of the High Plains this afternoon. RH values in the teens to low 20% range may temporarily overlap with sustained winds of 15 mph and higher gusts. Winds are forecast to remain gusty overnight, though humidity values should quickly recover to near 60%. Limited spatial coverage and the brevity of elevated conditions suggest low confidence in sustained elevated fire weather concerns this afternoon. ..Lyons.. 10/01/2022 .PREV DISCUSSION... /ISSUED 1237 AM CDT Sat Oct 01 2022/ ...Synopsis... A lee trough across the Central Plains will continue the dry and breezy conditions on Saturday. Corridors of elevated fire-weather conditions will be possible, mainly across western Kansas where relative humidity will drop to around 15-20 percent with sustained winds at 15-20 mph. The coverage and period of elevated fire-weather conditions. Due to this threat being brief and isolated, no critical areas are included at this time. In this area, fuels remain in the 80th to 90th percentile. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

MD 1849 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR SOUTHERN TO EASTERN UTAH AND WESTERN COLORADO
Mesoscale Discussion 1849 NWS Storm Prediction Center Norman OK 0102 PM CDT Fri Sep 30 2022 Areas affected...Southern to eastern Utah and western Colorado Concerning...Severe potential...Watch unlikely Valid 301802Z - 302000Z Probability of Watch Issuance...20 percent SUMMARY...Thunderstorms developing across southern and eastern Utah will gradually increase in intensity through the afternoon. These storms may produce strong to severe wind gusts, but will most likely remain too limited in coverage to require watch issuance. DISCUSSION...Convection across central/southern UT has shown signs of gradual intensification over the past 1-2 hours with deepening echo tops and a steady increase in lightning counts. This trend is likely being driven by a diurnal increase in buoyancy coupled with broad, but persistent lift ahead of an upper-level perturbation embedded within the circulation of the upper low over ID. As this perturbation continues to pivot east into UT, deep-layer shear will increase to around 30-40 knots and support storm organization. Modest low-level moisture will limit overall instability, but steep mid-level lapse rates (sampled by the 12 UTC SLC and GJT soundings) will support 500-1000 J/kg MUCAPE by mid/late afternoon. The low boundary-layer moisture content will also support steep low-level lapse rates where skies remain mostly clear. Latest RAP mesoanalysis estimates suggest 0-3 km lapse rates may already be as high as 8 C/km ahead of the deepening convection, which will support downdraft acceleration. A few instances of marginally severe hail are possible given the thermodynamic and somewhat elongated wind profiles, but strong to severe wind gusts will likely be the predominant hazard given the low-level thermodynamics. The isolated to scattered nature of the convection, coupled with the modulating effects of modest buoyancy, should limit the overall severe potential and the need for a watch this afternoon. ..Moore/Bunting.. 09/30/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...GJT...SLC... LAT...LON 39121095 39771010 40030929 39950858 39600806 38760768 37700816 37430902 37181051 37141166 37111248 37851264 38331214 39121095 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1203 PM CDT Fri Sep 30 2022 Valid 011200Z - 021200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... The severe-thunderstorm threat is expected to remain low on Saturday. ...Synopsis... The remnants of Ian are forecast to drift north/northeast on Saturday across western/central NC/VA toward the Chesapeake Bay vicinity. While moderate low-level winds and vertical shear will reside over the region, limited heating due to cloud cover and widespread precipitation will limit destabilization. Any stronger surface-based instability is expected to remain offshore the Mid-Atlantic coast through the period, limiting tornado potential across the Delmarva region. To the west, an upper low will meander over ID/WY/MT, while an upper ridge remains oriented from the lower MO Valley into the central/southern Plains. Several mid/upper shortwave impulses will rotate around the western upper low in the vicinity of the central/northern high Plains. Southeasterly upslope low-level winds will transport modest boundary-layer moisture northward into northeast CO into western NE. Stronger heating will reside to the east of this meager moist axis, but some weak destabilization will occur, aided by steep midlevel lapse rates. Modest vertical shear and weak instability should limit thunderstorm organization/intensity and overall severe potential, though some gusty outflow winds will be possible. ..Leitman.. 09/30/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1139 AM CDT Fri Sep 30 2022 Valid 301700Z - 011200Z The previous forecast remains valid with only minor expansion of the Elevated area farther north based on the latest guidance. Elevated to locally critical fire weather concerns will be possible with gusty winds and dry surface conditions near a lee trough this afternoon. Please see the previous discussion for more information. ..Lyons.. 09/30/2022 .PREV DISCUSSION... /ISSUED 1257 AM CDT Fri Sep 30 2022/ ...Synopsis... An upper level low will continue a gradual shift southward across the northern Rockies through the day on Friday. A surface low will deepen across the Central Plains with dry and windy conditions aiding in the potential for spread of any new fires that develop. ...Central Plains and Southeastern California... As the surface low deepens across the Central Plains, increased surface pressure gradients may result in increased south to southwesterly flow around 15-20 mph. Elevated fire-weather conditions will spread across the Central Plains as afternoon minimum relative humidity around 15-20 percent across the Texas and Oklahoma Panhandles. Elevated conditions will stretch as far north as western Kansas and southeastern Colorado. A few stations across western Kansas may briefly approach critical fire-weather conditions with relative humidity dropping to 15% and sustained winds at 20 mph. ERCs across the Central Plains into eastern Colorado remain in the 80-90th percentile. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

WW 0548 Status Updates
STATUS FOR WATCH 0548 HAS NOT BEEN ISSUED YET Read more

WW 548 TORNADO NC SC VA CW 301640Z - 010200Z
URGENT - IMMEDIATE BROADCAST REQUESTED Tornado Watch Number 548 NWS Storm Prediction Center Norman OK 1240 PM EDT Fri Sep 30 2022 The NWS Storm Prediction Center has issued a * Tornado Watch for portions of Eastern North Carolina Northeast South Carolina Southeast Virginia Coastal Waters * Effective this Friday afternoon and evening from 1240 PM until 1000 PM EDT. * Primary threats include... A few tornadoes possible Isolated damaging wind gusts to 70 mph possible SUMMARY...Thunderstorms capable of producing a few tornadoes will continue to develop and move rapidly northwest around the circulation of Hurricane Ian. The tornado potential will gradually shift north across the watch area through this afternoon and this evening. The tornado watch area is approximately along and 75 statute miles either side of a line from 40 miles east northeast of Norfolk VA to 60 miles southwest of Wilmington NC. For a complete depiction of the watch see the associated watch outline update (WOUS64 KWNS WOU8). PRECAUTIONARY/PREPAREDNESS ACTIONS... REMEMBER...A Tornado Watch means conditions are favorable for tornadoes and 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. && AVIATION...Tornadoes and a few severe thunderstorms with hail surface and aloft to 0 inches. Extreme turbulence and surface wind gusts to 60 knots. A few cumulonimbi with maximum tops to 450. Mean storm motion vector 14045. ...Bunting Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1113 AM CDT Fri Sep 30 2022 Valid 301630Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER EXTREME NORTHEAST SOUTH CAROLINA...EASTERN NORTH CAROLINA AND SOUTHEAST VIRGINIA... ...SUMMARY... A few tornadoes will be possible today across the coastal Carolinas and southeast Virginia, in association with Hurricane Ian. A few strong gusts may also occur across portions of Utah into Colorado Friday afternoon. ...NC/VA... Hurricane Ian will move inland this afternoon across the SC coast and continue moving north tonight. An associated warm front, currently extending northeast from the center along the southern NC coast, is forecast to lift northward in tandem with the center this afternoon. Richer boundary-layer moisture, characterized by dew points in the 70s, is expected to lift northward across eastern NC this afternoon and eventually into southeast VA by evening. Some potential for pockets of greater heating will exist as drier air is entrained into the circulation, contributing to areas of greater surfaced based instability across eastern NC. Strong low/mid-level flow around the circulation will contribute to low-level shear supportive of supercell structures with the risk for a few tornadoes, as supported by most 12z CAM solutions. Transient supercell characteristics have already been observed near and south of the southern NC coast this morning within the more favorable thermodynamic environment. ...UT/CO... Despite some morning cloud cover, surface heating will occur in advance of a cold front, resulting in modest buoyancy by afternoon. Moderately strong westerly mid-level flow (30-35 kts) will result in an environment favorable for some degree of updraft organization. Thunderstorms are expected to increase in coverage this afternoon in association with a southeast-moving upper low as modest large scale ascent develops over the area. Isolated strong/damaging gusts should be the primary severe hazard with the strongest storms through early evening. ..Bunting/Moore.. 09/30/2022 Read more

No watches are valid as of Thu Sep 29 18:08:01 UTC 2022.

MD 1845 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR PARTS OF WESTERN MT...FAR EASTERN ID...AND NORTHWEST WY
Mesoscale Discussion 1845 NWS Storm Prediction Center Norman OK 0106 PM CDT Thu Sep 29 2022 Areas affected...Parts of western MT...far eastern ID...and northwest WY Concerning...Severe potential...Watch unlikely Valid 291806Z - 292030Z Probability of Watch Issuance...5 percent SUMMARY...The risk of isolated strong to severe gusts and marginal hail should gradually increase in the next few hours. Overall, the severe risk is expected to remain marginal and localized. DISCUSSION...Latest water vapor imagery shows a closed midlevel low tracking slowly eastward across the Northwest, preceded by increasing DCVA/large-scale ascent characterized by modest midlevel height-falls over the last 12 hours. As the increasing ascent continues overspreading a weak north/south-oriented baroclinic zone from western MT into eastern ID, convection will gradually increase in coverage given continued destabilization/steepening low/midlevel lapse rates this afternoon. Regional VWP data depicts 30-40-kt south-southwesterly midlevel flow preceding the closed midlevel low, which should favor modestly elongated/straight midlevel hodographs (35-45 kt of effective shear) across western MT southward into eastern ID and northwest WY. While buoyancy will be somewhat marginal (generally driven by steep low/midlevel lapse rates), the combination of strengthening forcing for ascent and sufficient deep-layer shear could favor loosely organized convection as it spreads northeastward this afternoon. Marginal hail will be possible with any initial cellular development, though strong to severe gusts should be the main hazard as convection grows upscale into clusters or bands owing to the strengthening large-scale ascent amid straight hodographs. Overall, the severe threat is expected to remain marginal and localized. ..Weinman/Thompson.. 09/29/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BYZ...RIW...TFX...PIH...MSO... LAT...LON 44021131 44781154 45391201 46061243 46961311 47541367 48081387 48461357 48671302 48661173 48261105 47421037 46700996 45770971 44940953 43670964 43450998 43391080 43511120 44021131 Read more

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1236 PM CDT Thu Sep 29 2022 Valid 301200Z - 011200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE EASTERN NORTH CAROLINA/SOUTHEASTERN VIRGINIA VICINITY... ...SUMMARY... A few tornadoes will be possible Friday into Friday night across the coastal Carolinas and southeast Virginia, in association with Tropical Cyclone Ian. A few strong gusts may also occur across the southern and eastern Utah/western Colorado vicinity Friday afternoon. ...Synopsis... An upper low over the northern Rockies is forecast to drift slowly southward Friday, while expansion/evolution of an eastern U.S. low occurs as Ian begins to acquire hybrid/extratropical characteristics later in the period. At the surface, Hurricane Ian is forecast to be located off the southeastern U.S. coast early Friday, and is forecast by the National Hurricane Center to make landfall over coastal South Carolina during the afternoon. Ian's circulation is expected to become increasingly baroclinic with time, as it curves north-northwestward toward/into western North Carolina through the end of the period. ...Northeastern South Carolina and eastern North Carolina into southeastern Virginia... As Ian shifts inland/north-northwestward Friday, moist/tropical air being advected westward/northwestward into eastern portions of the Carolinas and Virginia will maintain modest CAPE within a pseudo "warm-sector." With favorably strong low-level shear east of the storm/south of a baroclinic/warm-frontal type boundary moving northwestward across Virginia, potential for rotating convective cells within bands east of Ian's center is apparent. As such, potential for a few tornadoes remains evident, warranting a bump upward to 5% tornado probability/SLGT risk from extreme northeastern South Carolina northward into southwestern Virginia. The risk will gradually shift northward with time, in tandem with Ian's progression, with the southeastern Virginia risk likely to continue into/through the overnight hours. ...Southern and eastern Utah into western Colorado... As the upper low drifts slowly southward, modestly enhanced west-southwesterly flow will be maintained across the Utah/Colorado area on the southeastern fringe of the cyclone. With cool air aloft, associated with the low, providing steep mid-level lapse rates, diurnal heating will contribute to modest (around 500 J/kg) mixed-layer CAPE to evolve through the afternoon. This will support initiation of scattered to isolated, low-topped storms, which may become locally sustained/organized given modestly supportive shear that is expected. This, combined with a rather deep/dry mixed layer may support locally gusty winds with stronger storms, and some potential for a gust or two to reach severe levels. ..Goss.. 09/29/2022 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1119 AM CDT Thu Sep 29 2022 Valid 291630Z - 301200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON/EVENING FROM NORTHERN UT INTO WESTERN MT... ...SUMMARY... A few strong to severe thunderstorms are possible from northern Utah and western Wyoming into western Montana this afternoon and evening. ...Northern UT into MT this afternoon/evening... A midlevel low will move slowly east-southeastward over the northern Rockies, as midlevel height rises occur upstream over the northeast Pacific. Ascent preceding the midlevel low/trough, and an associated low-midlevel baroclinic zone, will provide an environment to support thunderstorms this afternoon/evening from northern UT into MT. Regional 12z soundings revealed modest low-midlevel moisture and the potential for steep low-level lapse rates and weak surface-based buoyancy with surface heating/mixing. Thus, high-based thunderstorm development is expected this afternoon, with the potential for isolated strong outflow gusts based on inverted-v profiles and some downward momentum transfer. Isolated, marginally severe hail may occur in MT, closer to the midlevel cold core. ...Southeast Atlantic Coast through early Friday... The core of Tropical Storm Ian, which has some hybrid/baroclinic characteristics, is moving off the east central FL coast and is forecast to strengthen some while gradually turning more northward toward the Carolinas on Friday (see latest NHC forecasts for details). A cool/dry, continental air mass is entrenched across the Carolinas now, with widespread rainfall offshore. It will take until Friday during the day to bring richer moisture and surface-based buoyancy inland across northeast SC and coastal NC, so any severe/tornado threat should remain offshore until the day-2 forecast period. ..Thompson/Weinman.. 09/29/2022 Read more