Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jun 11 2025 19:29:50 ACUS03 KWNS 111929 SWODY3 SPC AC 111928 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0228 PM CDT Wed Jun 11 2025 Valid 131200Z - 141200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF MONTANA SOUTHEASTWARD INTO THE CENTRAL HIGH PLAINS... ....SUMMARY... Scattered severe storms may occur Friday from Montana into the central Plains, with hail and corridors of damaging winds possible. ....Synopsis... A mid/upper-level shortwave trough will move from the Pacific Northwest toward the northern Rockies/High Plains on Friday. Downstream, considerable model variance remains regarding the evolution of a weak mid/upper-level low initially centered over the Ozarks vicinity. This system is generally expected to move eastward and gradually weaken, but extensive convection in its vicinity on D1/Wednesday into D2/Thursday results in greater than normal uncertainty regarding its evolution by D3/Friday. ....MT southeastward into the central/southern High Plains... In advance of the approaching shortwave trough, low-level easterly flow to the north of a lee cyclone will transport moisture into parts of western/central MT and northern WY. Moderate destabilization and increasing deep-layer shear will support development of scattered strong to severe storms by afternoon. A few supercells will be possible initially as storms develop near the higher terrain of MT/WY, with a threat of hail and localized severe gusts as they move eastward. One or more clusters may grow upscale by evening, with corridors of strong to severe gusts possible. Deep-layer flow will be somewhat weaker into the central High Plains, but still sufficient to support modestly organized storms during the afternoon/evening. One or more clusters could eventually spread eastward into western NE/KS by evening, aided by a nocturnal low-level jet and accompanied by a severe-wind threat. Farther south, storms may be more isolated into the southern High Plains, but strong instability and marginal deep-layer shear could support isolated hail and severe-wind potential. ....Ozarks into the Mississippi Valley/Ohio Valley vicinity... Given the aforementioned uncertainty regarding the slow-moving mid/upper-level low near the Ozarks, confidence in the details of storm evolution near and downstream of this low are highly uncertain. In general, scattered to numerous thunderstorms will be possible during the afternoon/evening from the Ozarks and lower/mid MS Valley into the OH Valley, within a moist, moderately unstable, and weakly capped environment. Generally weak midlevel lapse rates and modest deep-layer flow/shear should tend to limit overall storm intensity, but isolated instances of damaging wind or hail cannot be ruled out across a broad area, given the expected coverage of storms. If convective augmentation of the mid/upper-level low results in stronger wind profiles than currently forecast, or if storms can develop along the southwest periphery of the low (where lapse rates and shear will be stronger, but forcing will be weaker), then a more organized severe threat could evolve. At this time, the threat appears too nebulous for severe probabilities. Farther north, a strong storm or two could develop near a remnant frontal boundary in the upper MS Valley vicinity, though a lack of strong large-scale ascent and uncertainty regarding the frontal position result in limited confidence regarding any localized severe threat. ....Mid Atlantic vicinity... A moderately unstable and weakly capped environment is also expected from parts PA southward into the Mid Atlantic and Carolinas Friday. Scattered storm development is expected during the afternoon. A modest westerly mid/upper-level flow regime could support a few strong cells/clusters. Poor midlevel lapse rates and weak flow below 700 mb may tend to limit a more organized severe threat, but localized instances of wind damage will be possible. ...Dean.. 06/11/2025 $$ = = = To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .