Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Aug 18 2025 01:03:39 ACUS01 KWNS 180102 SWODY1 SPC AC 180100 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0800 PM CDT Sun Aug 17 2025 Valid 180100Z - 181200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF THE CENTRAL/NORTHERN PLAINS AND UPPER MIDWEST... ....SUMMARY... Scattered thunderstorms over the central and northern Plains may pose a threat for damaging gusts and hail tonight, while a brief tornado remains possible over the Midwest this evening. ....Central and northern Plains... Weak ascent from a broad shortwave trough, visible in evening water-vapor imagery, is supporting scattered thunderstorm development across portions of western NE and SD this evening. Some clustering of initial cells has been noted over the High Plains this evening. Slight enhancement of southwesterly flow aloft attendant to the broad shortwave trough suggests some upscale growth is possible over southern SD and northern/central NE this evening into tonight. Aided by and increasing southwesterly low-level jet, severe gusts are possible over parts of NE and southern SD with a loosely organized cluster/MCS progressing east/southestward. Farther north along the front in the eastern Dakotas, scattered storms remain possible tonight, especially as low-level mass response increases at the nose of the low-level jet. Likely elevated, sporadic hail and or isolated damaging winds would be possible with any stronger clusters. Confidence in this scenario is low owing the weak but persistent subsidence in the wake of the MCV farther east. ....IA/MN... Ahead of a diffuse MCV, scattered thunderstorms have developed along an east-west oriented frontal zone. Along and south of this front, very moist surface conditions are supporting large buoyancy. Area VADs and forecast soundings show modest westerly flow aloft, primarily along the cool side of the boundary. Still, slight enhancement of low-level shear profiles and vertical vorticity along the wind shift could support a brief supercell/tornado threat with occasional stronger updrafts into this evening. With time, the threat should begin to diminish later tonight as the boundary layer begins to cool and the MCV continues eastward. ....Northern Rockies/northern High Plains... Scattered high-based thunderstorms ongoing this evening should continue into tonight as ascent attendant the shortwave trough over the Northwest spreads eastward. Moderate southwesterly flow aloft, and weak buoyancy atop steep low-level lapse rates will remain supportive of isolated severe gusts with the stronger downdrafts. The severe risk should steadily progress eastward into southeastern MT and the far western Dakotas before weakening after sunset tonight. ....Mid Atlantic... Lingering scattered thunderstorms may pose a risk for a damaging wind gust or two for a couple more hours this evening across portions of the DelMarVa. While general convective trends continue to suggest a decreasing threat with nocturnal stabilization underway, a stray gust or two cannot be ruled out before storms off shore tonight. ...Lyons.. 08/18/2025 $$ = = = 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 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .