Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Apr 12 2023 17:18:32 ACUS02 KWNS 121718 SWODY2 SPC AC 121716 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1216 PM CDT Wed Apr 12 2023 Valid 131200Z - 141200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF THE CENTRAL AND SOUTHERN HIGH PLAINS AND INTO PORTIONS OF THE SOUTHEAST.... ....SUMMARY... Isolated severe thunderstorms are possible across portions of the southern and central High Plains and portions of the Southeast States/Florida on Thursday. ....Synopsis... A mid-level closed low over the Gulf of Mexico is forecast to continue to slowly meander eastward while the associated surface circulation moves onshore early Thursday. Scattered strong thunderstorms should move inland early, and persist through much of the day. To the west, a mid-level trough digging over the central Rockies and northern Great Basin will shift eastward overspreading the central High Plains. A strong lee low is forecast to evolve aiding in the development of a dryline and weak moisture return over the western High Plains. Isolated severe thunderstorms are possible in the afternoon and evening ahead of the sharpening dryline. ....Southeastern States... As the closed low shifts northeastward across the central Gulf Coast, rapid low-level moistening is expected in its eastern quadrant early in the forecast period. Mid, to eventually upper, 60s F surface dewpoints will surge inland over portions of eastern MS/AL, into southern GA and much of FL by midday. Weak mid-level warm advection and a mostly uncapped surface warm sector should allow for loosely organized bands of scattered thunderstorms to move onshore and develop through much of the day. Limited by mostly cloudy skies, afternoon destabilization is not expected to be overly strong, but diffuse heating and returning surface moisture should be sufficient to support scattered thunderstorms and occasional stronger updrafts. Mid-level shear is also not particularly strong owing the weaker flow aloft on the eastern periphery of the upper-level circulation. However, enhanced easterly flow in the low to mid-levels supports some hodograph curvature/expansion in the lowest few kilometers. Given the favorable storm relative flow and larger SRH (200 m2/s2), transient supercell structures may evolve with the more persistent updrafts. The strongest storms may pose a risk for damaging wind gusts and a tornado or two into the early evening. A few storms may also be capable of marginally severe hail given cooler temperatures aloft. ....Central and southern High Plains... As the western US trough continues to deepen and shift eastward through the day, broad-scale ascent and an embedded shortwave trough will overspread a sharpening dryline/lee trough extending south from a lee low over western NE. Strong diurnal heating and mixing along the dryline will remove limited inhibition concurrent with northward returning surface moisture. While not excessively moist, surface dewpoints reaching the upper 30s to mid 40s F should be adequate for weak afternoon destabilization given the very warm temperatures and steep lapse rates. The warm temperatures and marginal moisture should support around 500 J/kg of MLCAPE allowing the development of isolated high-based storms late in the afternoon. Steepening low-level lapse rates will favor strong downdrafts and severe wind gust potential with any convection able to develop. The greatest converge of storms is currently expected over portions of the TX Panhandle into southwestern KS where deeper surface moisture and locally stronger surface convergence are expected along the dryline. Given the limited surface moisture, storms should diminish quickly after sunset with the loss of diurnal heating. A Marginal Risk area has been added from central NE to the southern TX Panhandle mainly for isolated damaging wind gusts. ...Lyons/Dean.. 04/12/2023 $$ = = = 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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .