SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0202 AM CDT Fri Apr 21 2023 Valid 231200Z - 241200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER SOUTHERN TEXAS... ...SUMMARY... A few storms may produce large hail Sunday over parts of southern Texas. ....Synopsis and Discussion... An upper low will be located near Lake Superior on Sunday with a large upper trough over the northeastern quarter of the CONUS. Meanwhile, a low-amplitude trough will move quickly eastward toward the Four Corners states, with an upper ridge well offshore the Pacific Coast. At the surface, high pressure will exist over much of the central and eastern CONUS, with a stalled front over the northern Gulf of Mexico. Western portions of this front will extend into southern TX during the day, but will shift south into far southern TX Sunday night. Ahead of this front, ample low-level moisture will exist with upper 60s F dewpoints common. Coupled with cool midlevel temperatures, this will yield MUCAPE over 2000 J/kg across southern TX. Forecast soundings in this region indicate a capping inversion just below 700 mb, but the moist boundary layer will be quite deep. Therefore, modest low-level theta-e advection in the vicinity of a weak pre-frontal trough may yield a few storms from south-central into southeast TX during the afternoon and evening. Steep mid and high-level lapse rates, modest westerlies aloft and good storm relative inflow in the low levels may favor at least isolated large hail or strong wind gusts. ..Jewell.. 04/21/2023
