Severe Storms

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1118 AM CDT Fri Oct 14 2022 Valid 141630Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe weather is not expected across the contiguous U.S. through tonight. ...DISCUSSION... Thunderstorms are most likely this afternoon over south FL, ahead of a weak cold front sagging southward across the peninsula. Low and mid-level vertical shear is rather weak, precluding a more organized severe threat. Showers and the possibility of isolated thunderstorms will also be present this afternoon across parts of south TX, eastern New England, and parts of MI. Weak thermodynamic profiles will limit any severe risk. ..Hart/Thornton.. 10/14/2022 Read more

SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1254 PM CDT Thu Oct 13 2022 Valid 141200Z - 151200Z ...CRITICAL FIRE WEATHER AREA FOR SOUTHEAST WYOMING INTO SOUTH-CENTRAL KANSAS... The primary change to the Outlook was to expand the Elevated highlights eastward across portions of the Lower/Middle MS Valley and northeastward across parts of the TN and OH Valleys. Through this corridor, confidence in the overlap of 20-25 percent minimum RH and 15-20 mph sustained west-southwesterly surface winds (with gusts upwards of 30 mph) has increased. While many of these areas have received rainfall over the last 72 hours, the higher totals have generally been focused both north and south of the expanded highlights. Therefore, fuels should be at least modestly receptive to wildfire spread, especially considering ongoing drought conditions. In addition, locally critical conditions (sustained surface winds of 20 mph amid 20 percent RH) will be possible over far western KY and far southeastern MO during peak heating. However, these conditions look too brief and localized for a Critical area at this time. Elsewhere, the previous forecast (see below) remains on track. ..Weinman.. 10/13/2022 .PREV DISCUSSION... /ISSUED 1246 AM CDT Thu Oct 13 2022/ ...Synopsis... On Friday, the upper-level low will swing southward into the Upper Midwest. At the surface, this will result in a tightening pressure gradient across the northern/central Plains. Cold air will be present beneath this upper low, but temperatures will warm with west/southward extent. Therefore, relative humidity will drop into the 20s across central Nebraska and into the teens across southeast Wyoming into southwest Nebraska, northeast Colorado and much of Kansas. In this region, winds are expected to be 20 to 25 mph due to the tight pressure gradient and strong mid-level flow. ERC values in this region are mostly above the 90th percentile and therefore, critical fire weather conditions are expected. ...Please see www.spc.noaa.gov/fire for graphic product... Read more

No watches are valid as of Thu Oct 13 17:57:01 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1210 PM CDT Thu Oct 13 2022 Valid 141200Z - 151200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe weather is not expected across the U.S. on Friday. ...Synopsis... A mean upper level trough will persist over the eastern U.S. on Friday, with an upper low and embedded shortwave trough pivoting east across the upper Great Lakes vicinity. Another upper low off the southern CA coast will meander southward toward northern Baja. between these two systems, shortwave upper ridging will be centered over the southern Rockies. At the surface, a cold front will shift eastward across New England with the southern extent of the front arcing across the western Atlantic offshore from the Mid-Atlantic and Southeast U.S. coasts and into northern/central FL. Surface high pressure behind the front across the Southeast, and weak lee troughing over the southern High Plains will result in southerly flow across the Southern Plains. Gulf moisture will return northward toward across much of TX into far southern OK. This warm advection regime may result in isolated showers and thunderstorms across parts of the TX coast, but negligible large-scale forcing will limit thunderstorm activity further north across TX/southern OK despite increasing moisture. A few lightning flashes may also occur ahead of the surface front across New England, but a cool boundary-layer and limited instability will preclude severe potential. Additional isolated lightning flashes are possible across south FL, but weak forcing and poor lapse rates/modest shear will preclude organized severe potential. ..Leitman.. 10/13/2022 Read more

MD 1870 CONCERNING SEVERE POTENTIAL...WATCH UNLIKELY FOR CENTRAL PA/NY
Mesoscale Discussion 1870 NWS Storm Prediction Center Norman OK 1157 AM CDT Thu Oct 13 2022 Areas affected...Central PA/NY Concerning...Severe potential...Watch unlikely Valid 131657Z - 131900Z Probability of Watch Issuance...20 percent SUMMARY...Isolated wind damage will be possible with low-topped convection this afternoon. DISCUSSION...Low-topped convection has gradually consolidated over the past few hours along an eastward-moving cold front across parts of central PA/NY, with peak wind gusts generally in the 30-45 mph range thus far. Buoyancy will remain quite limited, but SBCAPE may increase into the 200-400 J/kg range where temperatures can rise into the mid/upper 60s F, and convection is likely to be sustained along the front through the remainder of the afternoon. The strongest low-level flow will likely remain displaced somewhat east of the front, in association with a 50+ kt low-level jet. However, low-level flow/shear will still be sufficient for isolated wind-damage potential in association with any small bowing segments or mesovortices along the frontal band, especially if pockets of slightly stronger heating/destabilization can materialize in advance of the front. At this time, the threat is expected to remain too marginal/isolated for watch issuance. ..Dean/Hart.. 10/13/2022 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...BTV...ALY...BGM...BUF...CTP... LAT...LON 40237806 41407760 43187675 44327615 44977502 44957386 43657447 42237541 40437656 39817688 39827737 39757828 40237806 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1152 AM CDT Thu Oct 13 2022 Valid 131700Z - 141200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE NORTHERN/CENTRAL PLAINS AND THE MIDDLE MISSISSIPPI VALLEY... The forecast generally remains on track, and only minor adjustments were made to the Outlook based on the latest observational data and high-resolution guidance consensus. In particular, the Critical highlights were expanded slightly southeastward into the Middle MS Valley, where minimal rainfall accumulations over the last 72 hours should support at least modestly receptive fuels given areas of moderate to extreme drought. Surface observations across this area already show 20+ mph sustained northwesterly surface winds (with higher gusts) amid 20-30 percent RH. And, continued boundary-layer mixing into enhanced dry air aloft per low-level water vapor imagery and 12Z observed soundings should foster additional RH reductions this afternoon. For additional details, see the previous discussion below. ..Weinman.. 10/13/2022 .PREV DISCUSSION... /ISSUED 1245 AM CDT Thu Oct 13 2022/ ...Synopsis... Very strong northwesterly flow is expected across much of the northern and central Plains. These strong winds will come as a result of the tightening pressure gradient and deep vertical mixing beneath the very strong mid-level flow. Widespread relative humidity in the teens is expected across the eastern half of the northern and central Plains. However, these dry and breezy conditions will also persist into portions of Ohio and Missouri. However, recent moderate to heavy rainfall has limited fuel receptiveness across these regions. Therefore, have kept the Critical delineation farther west. Some isolated areas may have received less precipitation and therefore may have receptive fuels. Given the strength of the winds and the dryness, have kept an Elevated delineation across this region to cover the threat for some large fire growth. ...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 1121 AM CDT Thu Oct 13 2022 Valid 131630Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND EVENING OVER PARTS OF THE NORTHEAST AND MID-ATLANTIC REGIONS...AND ACROSS THE TEXAS GULF COAST AREA.... ...SUMMARY... Isolated damaging winds and a brief tornado are possible across parts of the Northeast and Mid-Atlantic States. Isolated severe hail and locally strong gusts are also possible across a portion of coastal Texas. Threats in both areas are most likely during the afternoon to early evening. ...Northeast and Mid-Atlantic States... Morning water vapor loop shows a broad upper trough over the Great Lakes and northeast states today, with a 90+ mid level jet max tracking across the mid-MS Valley. Ahead of the upper system, a surface cold front extends from western NY/PA southward into GA/AL. As the cold front and jet max track eastward, showers and thunderstorms are expected to increase in coverage and intensity along/ahead of the front. The pre-frontal air mass is quite cloudy, with limited potential for afternoon destabilization. Nevertheless, frontal forcing and strong winds aloft will help to induce a few low-topped but fast-moving bowing structures. Present indications are that the overall severe threat will be marginal, but locally damaging wind gusts may occur with the stronger or more organized line segments. An isolated brief tornado is also possible along the line this afternoon. ...Texas Gulf Coast... Visible satellite imagery shows mostly clear skies over coastal TX, where dewpoints in the 70s and afternoon highs will rise into the lower 90s. A weak surface cold front will sag into this environment later this afternoon, aiding in the development of scattered thunderstorms. Forecast soundings show favorable thermodynamic parameters and deep layer shear for a rotating storm or two capable of hail. However, low-level winds are weak and overall forcing is limited. This is expected to keep the severe risk marginal. ..Hart/Thornton.. 10/13/2022 Read more

No watches are valid as of Wed Oct 12 17:51:01 UTC 2022.

No Mesoscale Discussions are in effect as of Wed Oct 12 17:51:01 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1214 PM CDT Wed Oct 12 2022 Valid 131200Z - 141200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST NEW YORK INTO NORTHEAST NORTH CAROLINA... ...SUMMARY... A band of relatively low-topped thunderstorms are forecast to move across portions of the eastern U.S. east of the Appalachians. A stronger afternoon storm or two may produce strong/gusty winds or a brief tornado from the Catskills vicinity southward across central Virginia. ...Synopsis... A seasonally strong upper low and attendant trough will be in place across western Ontario and extend southward across much of the central U.S. The upper trough will slowly pivot eastward toward the Appalachians during the period, bring strong mid/upper level southwesterly flow over the Northeast into the Mid-Atlantic. At the surface, low pressure over Ontario and the upper Great Lakes will pivot beneath the upper low. Meanwhile, a surface cold front will extend from western NY/PA into the central Appalachians and southwestward toward the central Gulf Coast vicinity. The front will progress eastward through the period, oriented from western New England, southward to the offshore waters of the Mid-Atlantic/Carolinas coast before arcing westward across northern FL and into the Gulf of Mexico. A Marginal risk of severe storms is expected ahead of the front from parts of southern NY into eastern VA/NC. ...Portions of NY into VA/NC... Showers and thunderstorms will likely be ongoing along the cold front Thursday morning across western NY/PA into eastern OH, with additional precipitation occurring in the warm advection regime from eastern PA toward the Chesapeake/coastal VA/NC. Destabilization will be limited by precipitation and cloud cover, especially across NY/PA. However, strong deep-layer southwesterly flow will aid in the development of an organized line of low-topped convection along the cold front. A few strong gusts may accompany this line of storms. With southward extent into eastern VA and the Chesapeake Bay/northeast NC vicinity, stronger destabilization is expected where at least filtered heating amid 60s F dewpoints should result in 500-1000 J/kg MLCAPE. A mix of thunderstorm clusters and more discrete cells are possible across this area. Backed low-level flow and will contribute to enlarged, favorably curved low-level hodographs, and a few rotating storms are possible. Isolated strong gusts and/or a brief tornado will be possible with activity across southern portions of the Marginal risk area. ..Leitman.. 10/12/2022 Read more

SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1148 AM CDT Wed Oct 12 2022 Valid 121630Z - 131200Z ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE MID-SOUTH AND LOWER MISSISSIPPI/TENNESSEE VALLEYS... ...SUMMARY... Scattered severe thunderstorms producing a couple brief tornadoes, damaging winds, and large hail are possible across parts of the Mid-South and the Lower Mississippi to Tennessee Valleys, mainly this afternoon and evening. ...Mid-South to Lower Mississippi/Tennessee Valleys... A band of storms are ongoing across northern Arkansas and far southeast Missouri at late morning ahead of/near an east/southeastward-moving cold front. Modest low-level moistening continues to occur (50s to lower 60s F surface dewpoints) immediately ahead of this convection across the Mid-South, with ample insolation also occurring within the warm sector. This should lead an increase in both coverage and intensity of storms through the afternoon. A QLCS should evolve from eastern Arkansas/northern Mississippi into Tennessee, with additional and somewhat more discrete development anticipated farther south/southwest toward the ArkLaTex. Damaging winds and large hail are expected to be the most common/probable hazards, but a couple of brief tornadoes might also occur. ...Kentucky/Ohio... Some clearing is noted in visible satellite imagery as of late morning across western/middle Tennessee into Kentucky, but uncertainties linger regarding the extent/degree of surface-based destabilization later today. Will maintain low severe probabilities across the region as even modest destabilization coupled with adequate low-level hodograph curvature could support a supercell or two capable of a brief tornado and/or locally damaging winds. ...Southeast including Alabama/southern Georgia... Persistent warm advection in conjunction with an effective/850 mb west-east front will likely maintain slow-eastward-progressive scattered thunderstorms into the afternoon and evening. Diurnal heating and some thinning of cloud cover could allow some of these storms to become more surface based this afternoon, with locally damaging winds a possibility aside from severe hail. ..Guyer/Wendt.. 10/12/2022 Read more

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1149 AM CDT Wed Oct 12 2022 Valid 121700Z - 131200Z ...CRITICAL FIRE WEATHER AREA FOR PORTIONS OF THE NORTHERN PLAINS... Minor adjustments were made with the forecast remaining largely on track. The Critical risk area was expanded into south-central South Dakota where low relative humidity and strong winds will likely lead to more active fire behavior in ongoing fires. Surface observations show sustained winds of 20+ mph and gusts up to 45 mph across portions of the Dakotas. Expect warming and drying through the day, as mid-level cloud cover decreases and boundary-layer deepening/mixing allows relative humidity to decrease to around 20-25 percent. VWP profiles show 50+ mph winds above the surface, which will likely lead to a further increase in the winds as the boundary layer deepens through the afternoon. The Elevated risk was extended southward into Kansas to account for areas where relative humidity may approach 20-25 percent with sustained winds at 15-20 mph. Further east, similar conditions will occur, but rainfall in the last 24 hours may have made fuels less receptive. See the previous discussion for more details. ..Thornton/Weinman.. 10/12/2022 .PREV DISCUSSION... /ISSUED 0157 AM CDT Wed Oct 12 2022/ ...Synopsis... Very strong northwesterly flow will overspread the northern Plains today as a mid-level trough amplifies. Beneath the strongest mid-level jet streak, winds of 30 to 35 mph are expected at the surface. Relative humidity will drop into the upper teens from far northeast Montana across western North Dakota and into northern South Dakota. Elsewhere, relative humidity will likely be too high to warrant a critical delineation. Farther south, across central and eastern Nebraska, some critical conditions may also develop. However, Tuesday night thunderstorms brought some rainfall to this region and therefore, fuels will likely not be as receptive. ...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 1227 PM CDT Tue Oct 11 2022 Valid 121200Z - 131200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM THE LOWER MS VALLEY TO THE TN AND OH VALLEYS VICINITY... ...SUMMARY... Thunderstorms, a few of which may produce strong/gusty winds and marginal hail, are expected Wednesday across parts of the Ohio/Mid and Lower Mississippi/Tennessee Valleys, and westward to the Arklatex region. ...Synopsis... A large-scale upper trough will develop eastward from the Plains on Wednesday morning, becoming oriented from the Upper Midwest to the Southeast by Thursday morning. Enhanced southwesterly flow ahead of the trough will overspread much of the Midwest, and decreasing with southward extent into the southern U.S. At the surface, a cold front extending from WI southwestward into western OK/northwest TX will sweep eastward during the forecast period. By Thursday morning, the front is expected to extend from western NY/PA toward Middle TN, southwestward toward the TX coast. ...Middle TN into the OH Valley Vicinity... Stronger vertical shear will be in place across the region, closer to the core of the upper trough and within the stronger surface pressure gradient associated with a low over Ontario. South/southwesterly low-level flow will bring a narrow corridor of upper 50s and 60s F surface dewpoints northward ahead of the eastward-advancing cold front. Heating will be limited by cloud cover and possibly early day showers. However, cooling aloft will support modestly steep midlevel lapse rates, and MLCAPE of a few hundred J/kg will be possible amid 30+ kt effective shear magnitudes. Transient supercells and briefly organized clusters could produce isolated strong storms capable of hail and strong gusts. Low-level instability will be limited, but enlarged, favorably curved surface-3 km hodographs suggest a brief tornado also could occur. ...AR into western TN/northern MS Vicinity... Additional thunderstorms are expected to develop along the front during the afternoon across AR and shift east/southeast into western TN and northern MS. Some guidance suggest an increase in hail and strong gust potential will accompany these cells. Stronger heating is expected along this corridor ahead of the front, resulting in steeper low-level lapse rates, while cooling aloft associated with the main upper trough supports steepening mid-level lapse rates. Effective shear magnitudes around 25-35 kt and favorable hodographs suggest some rotating cells will be possible. A narrow corridor of relative greater severe potential may exist within this corridor and an upgrade to Slight risk may be needed in subsequent outlooks if forecast confidence increases. ...Southern MS/AL... A lead shortwave impulse is expected to move across MS/AL during the morning/early afternoon. Scattered thunderstorms are expected in this pre-frontal warm advection regime. However, low-level thermodynamics appear weak given limited heating. Midlevel temperatures also are only forecast to be around -8 to -10 C, resulting in poor midlevel lapse rates. Effective shear magnitudes around 20-30 kt, and somewhat elongated hodographs could result in some briefly organized cells within morning thunderstorm clusters across parts of MS/AL and the FL Panhandle, though severe potential appears limited at this time. By the time the cold front moves into southern MS/AL during the evening/overnight, considerable mid/upper level drying is forecast and thunderstorms are not expected to be severe. ..Leitman.. 10/11/2022 Read more

No watches are valid as of Tue Oct 11 17:31:01 UTC 2022.

No Mesoscale Discussions are in effect as of Tue Oct 11 17:31:01 UTC 2022.

SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook NWS Storm Prediction Center Norman OK 1201 PM CDT Tue Oct 11 2022 Valid 111700Z - 121200Z A southward-advancing surface cold front will continue across the Plains this afternoon. Winds gusting 40-50 mph have been observed in surface observations across Wyoming and Montana this morning. Strong west to southwest surface winds will overlap with low relative humidity ahead of the cold front across much of the central Plains this afternoon. Dry northerly flow will be possible behind the frontal passage. Within the central High Plains Elevated area, brief periods of near-critical fire-weather conditions may be possible across the Nebraska Panhandle southward into northeastern Colorado and northwestern Kansas. ..Thornton/Weinman.. 10/11/2022 .PREV DISCUSSION... /ISSUED 0155 AM CDT Tue Oct 11 2022/ ...Synopsis... A strong upper-level trough will continue to amplify across the central CONUS today. Meanwhile a surface low will continue to deepen as it moves east across the Canadian Prairie. ...Portions of the central Plains and central High Plains... A cold front will move through the Plains today. In its wake, dry and breezy conditions will develop with winds of 15 to 25 mph and relative humidity of 10 to 25 percent expected from southeast Wyoming/northeast Colorado into Nebraska and northwest Kansas. Some critical conditions are likely, but are not expected to persist for long enough as cooler air moves in behind the front and relative humidity improves as a result. ...Portions of the Northern Plains... Very windy conditions (25 to 30 mph sustained winds) are expected in the wake of the cold front across the northern Plains. Relative humidity may be too high to support fire weather concerns in some locations, but relative humidity of 20-30 percent is expected from southeast Montana to north-central South Dakota where elevated to locally critical conditions are possible. ...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 1128 AM CDT Tue Oct 11 2022 Valid 111630Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS TONIGHT FROM THE UPPER MIDWEST INTO PARTS OF THE CENTRAL PLAINS... ...SUMMARY... Isolated severe wind and hail will be possible across parts of the Upper Midwest to the central Great Plains tonight through early Wednesday morning. ...KS to WI tonight... A northern stream shortwave trough will continue to dig southeastward and amplify over the northern Plains, as a lower latitude trough and moisture plume eject northeastward from OK/KS/MO toward IL today. A few (mainly elevated) thunderstorms will be possible within the low-midlevel moisture plume from eastern OK across MO into IL this afternoon and Lower MI by this evening. To the west of the thicker clouds and in advance of a cold front associated with the amplifying northern Plains midlevel trough, a modest increase in low-level moisture will occur today from OK to IA and WI. Though the richer low-level moisture will be confined much farther south into the Gulf of Mexico along a remnant frontal zone and with a developing tropical system in the Bay of Campeche, boundary-layer dewpoints in the mid 50s to lower 60s will spread northeastward in advance of the cold front. Regional 12z soundings revealed a relatively warm elevated mixed layer over the central/northern Plains, which will act to cap the boundary layer through this afternoon. By late evening, ascent atop the frontal surface should be sufficient for thunderstorm development across MN/western WI where the cap will be weaker, with subsequent storm development later tonight and farther southwest into KS/MO/IA. Lingering steep midlevel lapse rates and modest cloud-layer shear will support the potential for isolated large hail and strong surface wind gusts with bands of convection slightly behind the surface cold front (better chance for strong winds farther south toward KS/MO/IA). ...Southwest TX and interior southern CA this afternoon... An isolated strong storm may form this afternoon over the high terrain near Fort Stockton, where deep-layer vertical shear and buoyancy could support low-end supercell potential. However, storm coverage will be isolated at best and warming is expected in the mid levels, so any severe threat should remain too low to warrant an outlook area. Otherwise, isolated strong outflow gusts may occur in the higher terrain across southern CA this afternoon, where deeper mixing results in inverted-v profiles. The threat for severe storms appears to be low enough to preclude an outlook area. ..Thompson/Wendt.. 10/11/2022 Read more

No watches are valid as of Mon Oct 10 17:27:02 UTC 2022.

No Mesoscale Discussions are in effect as of Mon Oct 10 17:27:02 UTC 2022.

SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1220 PM CDT Mon Oct 10 2022 Valid 111200Z - 121200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF THE UPPER MISSISSIPPI VALLEY...MIDWEST...AND CENTRAL/SOUTHERN PLAINS... ...SUMMARY... Thunderstorms capable of isolated hail and strong wind gusts will be possible from parts of upper Mississippi Valley into the Midwest and central/southern Plains, mainly Tuesday evening into the overnight hours. ...Synopsis... A deep mid/upper-level trough initially covering much of western Canada is forecast to amplify and move southeastward on Tuesday, with the southern portion of the trough building into much of the Great Plains and upper Mississippi Valley by early Wednesday morning. A deep surface low is forecast to move eastward across northern Manitoba, as a trailing cold front sweeps through the northern/central Plains and eventually the upper Midwest. ...Upper MS Valley/Midwest into the central/southern Plains... Modest low-level moisture is expected to stream northward into parts of the Plains/Midwest and upper MS Valley during the day on Tuesday, in advance of the cold front. Relatively steep midlevel lapse rates will support the development of weak to locally moderate buoyancy, though a substantial capping inversion will likely limit thunderstorm initiation for much of the day. Large-scale ascent attendant to the cold front and amplifying upper-level trough may allow for thunderstorm development along the front during the evening, initially over parts of the upper Midwest/MS Valley, and then farther southwest into the central and possibly southern Plains by later Tuesday night. Given the anticipated nocturnal timing of larger-scale storm development, initial convection will likely be somewhat elevated, but sufficient buoyancy and effective shear of 25-35 kt will support the potential for organized multicells and perhaps a supercell or two. Isolated hail may be the most prevalent threat, given favorably cool temperatures aloft and relatively steep midlevel lapse rates. However, even with convection likely to become increasingly elevated with time, isolated strong/damaging gusts cannot be ruled out, given the presence of relatively strong low-level flow and a residual well-mixed boundary layer across parts of the warm sector. A broad Marginal Risk has been maintained for this outlook, though higher probabilities may eventually be needed across parts of the upper MS Valley/Midwest, especially if confidence increases in earlier, near-surface-based storm initiation. The threat becomes increasingly conditional with southwestward extent into the southern Plains, where the environment will be favorable for strong elevated storms late Tuesday night, but large-scale ascent will be weaker compared to areas to the northeast. ..Dean.. 10/10/2022 Read more