Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Oct 18 2024 16:32:37 ACUS01 KWNS 181632 SWODY1 SPC AC 181630 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 AM CDT Fri Oct 18 2024 Valid 181630Z - 191200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PARTS OF THE SOUTHERN ROCKIES AND SOUTHERN HIGH PLAINS AND FROM NORTHERN ARIZONA INTO SOUTHWEST COLORADO... ....SUMMARY... Isolated severe hail, damaging gusts and a tornado or two will be possible this afternoon and evening over parts of the southern Rockies and southern High Plains. An isolated threat for severe may locally develop from northern Arizona into southwest Colorado. ....Synopsis... Water-vapor imagery shows a mid- to upper-level low centered over the NV/UT/AZ border vicinity and this feature will move east-southeast into northern AZ before nearly stalling later tonight. An associated cold front will push east across the Four Corners through this afternoon. Farther east, the southwestern extension of a Midwest front will push southward through eastern CO before decelerating near the Raton Mesa. ....Northern AZ into southwest CO through this afternoon... Strong large-scale ascent immediately ahead of the upper low will gradually shift east across the Mogollon Rim through the early afternoon. The 12 UTC Flagstaff, AZ raob showed weak buoyancy but an enlarged hodograph. Visible-satellite and radar imagery show widely scattered deepening convection near the Rim on the northern extent of a moist axis from the lower deserts into northern AZ. Forecast soundings show surface-based buoyancy (100-400 J/kg SBCAPE) across northern/eastern AZ. As a result, a couple of shallow transient-rotating storms may yield short-duration risk for a brief tornado and/or locally strong gust. The risk for strong/severe gusts may extend as far northeast as southwest CO with a stronger storm or two before cold front passage later today. ....Southern High Plains and escarpments... Late morning surface analysis and visible-satellite imagery denote a low-level moisture plume from west TX into eastern NM, where dewpoints range in the 50s deg F. Heating through the mid-late afternoon will yield generally 500-1000 J/kg MLCAPE across eastern NM. Model guidance indicates a weakened capping inversion towards the late afternoon over the Eastern Plains of NM. Initially isolated to widely scattered storm coverage during the 21z-00z window will transition to greater storm coverage towards sunset and into the overnight, especially over the northeast quarter of NM. Despite the time-lagged nature of the forcing associated with the upper low, storms will mature into the evening. The stronger storms will potentially be capable of an isolated risk for hail/wind. Where surface-based buoyancy lingers near the escarpment in the northeast quarter of NM during the early evening, a threat for a tornado may develop. ...Smith/Squitieri.. 10/18/2024 $$ = = = 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) .