Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jul 30 2023 05:46:33 ACUS01 KWNS 300546 SWODY1 SPC AC 300545 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1245 AM CDT Sun Jul 30 2023 Valid 301200Z - 311200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE NORTHERN AND CENTRAL HIGH PLAINS... ....SUMMARY... Scattered severe thunderstorms are expected across portions of the northern and central High Plains. Very large hail and damaging winds are expected. More isolated strong to severe storms are possible Sunday across parts of the Southeast and lower deserts region of the Southwest. ....Northern/Central High Plains... Dominant upper ridge is anchored over the southern Rockies/Four Corners region early this morning. Latest water-vapor imagery suggests several weak short-wave troughs are ejecting northeast around the western/northern periphery of this feature. One such short wave is located over western ID with another prominent vort located over northeast CA. 00z model guidance suggests these features will top the ridge over central MT by 31/00z then dig southeast across the western Dakotas Sunday evening. In response to the short wave, lee surface trough should remain oriented from southeast WY into north-central MT. This will ensure favorable easterly boundary-layer component across the northern Plains where strong surface heating is forecast during the afternoon. As temperatures warm into the lower 90s, CINH will weaken such that deep convection is expected to develop. Initial updrafts will likely evolve over the higher terrain of southwest MT into northern WY. Forecast soundings exhibit substantial surface-6km shear with at least 2km southeasterly low-level flow. Current thinking is supercells will develop then mature as they propagate across the lower elevations of southern/eastern MT into northeast WY. Very steep lapse rates and MLCAPE in excess of 2000 J/kg should aid the production of potentially very large hail (in excess of 2"). Some increase in LLJ during the evening is expected to aid upscale growth of this activity as it propagates southeast toward the Black Hills. ....Elsewhere... Southern influence of OH Valley trough will contribute to scattered robust convection across the Southeast later today. Latest model guidance suggests strong/potentially severe thunderstorms should evolve from central MS to central GA. This activity will propagate slowly southeast with an attendant threat for gusty winds. Notable short-wave trough is currently located over northwest Mexico. Northern extent of this feature will result in 500mb flow strengthening near the international border. Additionally, seasonally high PW values will extend across the Gulf of CA into the lower CO River Valley. High-based convection that develops across this region could produce gusty winds, potentially in excess of 50kt. ...Darrow/Bentley.. 07/30/2023 $$ = = = 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) .