Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun May 11 2025 04:42:11 ACUS02 KWNS 110442 SWODY2 SPC AC 110440 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1140 PM CDT Sat May 10 2025 Valid 121200Z - 131200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS MONDAY ACROSS THE FL PENINSULA THROUGH NORTHEASTERN FL...MUCH OF GA AND SC...ADJACENT PORTIONS OF NC...NRN/ERN AL...ADJACENT SRN TN... ....SUMMARY... Scattered strong thunderstorms may impact parts of the Southeast on Monday, particularly a corridor across the Florida Peninsula into the South Carolina Piedmont, where strongest activity may pose a risk for producing a couple of tornadoes and locally strong surface gusts. ....Discussion... Latest model output remains similar to prior runs concerning the mid/upper flow evolution through this period. Within the amplified, split westerlies, one significant trough is forecast to continue digging inland of the U.S. Pacific coast, downstream of a prominent ridge now building across the mid-latitude eastern Pacific. It still appears that at least one notable smaller-scale perturbation emerging from this trough will accelerate northeast of the northern U.S. Rockies into the Canadian Prairies, around the northwestern periphery of broad downstream ridging encompassing much of the U.S. northern Great Plains through the Great Lakes and St. Lawrence Valley. In lower-levels, models indicate that deeper surface troughing will shift east of the Canadian and northern U.S. Rockies into Saskatchewan/Manitoba and the Dakotas, while deepening southward through the southern high plains. However, destabilization near this feature is likely to be significantly inhibited by warm air aloft, and the lack of appreciable low-level moisture return due to the continuing presence of a broad mid/upper low initially centered across the lower Mississippi Valley. Cut off from the stronger westerlies, to the south of the broad mid-level ridging, movement of this low is likely to remain slow; however, models indicate that it will probably elongate north-northeastward across the Mid South and lower Ohio Valley, while taking on a negative tilt east of the lower Mississippi Valley into Southeast. In lower levels, this may be accompanied by broad, weak surface troughing developing across much of the Southeast, as surface ridging slowly shifts east of the Atlantic Seaboard. ....Southeast... Differences linger among the various model output, but the gradient between the low-level ridging and troughing may continue to support a belt of modest southerly low-level flow (20-30+ kt around 850 mb) along a corridor roughly from the Florida Peninsula into the South Carolina Piedmont. It appears probable that this will coincide with a deep lower/mid-tropospheric moist plume emanating from the lower latitudes, beneath a belt of moderate to strong, difluent southwesterly high-level flow Much of this corridor may be impacted by considerable remnant convectively generated cloud cover, and perhaps continuing scattered thunderstorm development, at the outset of the period. However, the environment appears at least conditionally supportive of organized convection, including supercells, with potential to produce tornadoes and damaging wind gusts. And breaks in the cloud cover during the day may allow for sufficient insolation and boundary-layer destabilization to allow for some of this potential to be realized. Otherwise, closer to the mid-level cold core, models suggest that forcing for ascent downstream of an embedded cyclonic vorticity center may aid thunderstorm development across the northern/eastern Alabama into western Georgia vicinity. Despite at least some low-level drying in the wake of the aforementioned moist plume, thermodynamic profiles might still become conducive to small to marginally severe hail in widely scattered stronger cells, in the presence of modest deep-layer shear. ...Kerr.. 05/11/2025 $$ = = = 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) .