Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Apr 03 2025 05:41:57 ACUS01 KWNS 030541 SWODY1 SPC AC 030539 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1239 AM CDT Thu Apr 03 2025 Valid 031200Z - 041200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM THE ARKLATEX REGION INTO WESTERN TENNESSEE... ....SUMMARY... Severe thunderstorms are expected along/near a frontal zone from the southern Plains into the Tennessee Valley region. The most concentrated corridor will be from the Arklatex into western Tennessee were very large hail and a few strong tornadoes are possible. ....Southern Plains to the Tennessee Valley Region... Western U.S. trough continues to settle south with the strongest flow now extending across northern Mexico within the base of this feature. As a result, latest model guidance suggests broad height rises will occur across much of the CONUS today with the only appreciable falls expected over northern Mexico and across New England. Even so, at least one notable disturbance will eject into the southern Plains during the day1 period. Latest water-vapor imagery suggests a short wave is approaching far West TX, as a new baroclinic leaf is beginning to mature immediately downstream from NM into northeast Mexico. In response, southeasterly 1km winds are increasing across much of TX and 50kt LLJ should focus into the Arklatex by daybreak. In the absence of appreciable large-scale ascent, LLJ will likely modulate convective processes much of the period; although, diurnal heating will also contribute south of the synoptic front. Early this morning, synoptic front extends across western KY-central AR-southwest TX. Seasonally high PW values (1.5-1.8 inches) will extend along this frontal zone from TX into the TN Valley, and modestly steep mid-level lapse rates will persist along this corridor. As a result, forecast soundings exhibit substantial MUCAPE north of the wind shift, with SBCAPE in excess of 3000 J/kg, just south of the synoptic front by mid afternoon. Strong/severe elevated convection is expected to develop prior to the start of the period along the nose of the LLJ. Supercells could certainly produce large/very large hail given thermodynamic profiles. Latest thinking is the frontal zone will move very little through the period and a sharp demarcation between surface-based and elevated convection will be noted. Of particular concern will be the updrafts that generate along, just south of the wind shift across the Arklatex by mid afternoon. Deep-layer flow favors updrafts tracking along the frontal zone, and low-level shear will be maximized within a very moist and strongly sheared environment. In addition to very large hail, a few strong tornadoes may develop with supercells that maintain their surface-based inflow. LLJ will gradually lift across the TN Valley into the OH Valley during the latter half of the period, then increase again across TX late. Lack of meaningful forcing across much of the eastern TN Valley region suggests diurnal heating will be the primary instigator in robust convective development. ...Darrow/Weinman.. 04/03/2025 $$ = = = 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .