Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Jun 12 2023 19:51:39 ACUS01 KWNS 121951 SWODY1 SPC AC 121949 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0249 PM CDT Mon Jun 12 2023 Valid 122000Z - 131200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PARTS OF CENTRAL TEXAS... ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE CENTRAL HIGH PLAINS AND FROM THE SOUTHERN PLAINS EASTWARD ALONG THE NORTHERN GULF COAST STATES... ....SUMMARY... Severe thunderstorms capable of very large hail, damaging winds and a couple of tornadoes are expected this afternoon/evening across central Texas. Damaging winds and/or large hail will also be possible from the southern High Plains to the Gulf Coast, and across the Mid-Atlantic. Little change was needed at 20Z to the existing outlook. Severe storms have formed relatively early over northern Louisiana, and from the Front Range into northeast New Mexico. Continued heating/destabilization and lengthening hodographs will favor cells capable of large hail. The most favorable area of severe storms including very large/damaging hail will be later today over central Texas. Here, visible imagery show continued growth of cumulus fields, which are situated both near an east-west outflow boundary and on the nose of the low-level lapse rate plume emanating out of southwest Texas. This area should favor at least isolated supercells by late afternoon. ...Jewell.. 06/12/2023 ..PREV DISCUSSION... /ISSUED 1127 AM CDT Mon Jun 12 2023/ ....TX area this afternoon through tonight... A front has stalled across central TX, and the cool air north of the front is being reinforced by elevated convection near the Red River. Visible satellite imagery suggest that strong surface heating will continue into the afternoon farther south from the Edwards Plateau into central TX, where a belt of low-mid 70s boundary-layer dewpoints will coincide with the surface front. A warm elevated mixed layer and cap currently reside over this area, but warming temperatures into the 90s will reduce convective inhibition in a small area by mid-late afternoon between SJT-ABI-BWD. Thunderstorm development becomes probable by 21-23z in this zone, where MLCAPE of 3000-4000 J/kg, steep midlevel lapse rates, and unusually long hodographs/strong vertical shear will all favor intense supercells. Storm splits will be possible initially with somewhat straight hodographs, and these storms will be capable of producing very large hail of 3-4 inches in diameter. There will be a narrow window of opportunity for a couple of tornadoes with any supercell that can move along the zone of the mid 70s dewpoints and stronger low-level shear/larger hodograph curvature along the stalled front. There will be the potential for some storm clustering this evening, with continued large hail and damaging-wind threats. There will be some potential for occasional large hail with elevated storms through this evening in the zone of warm advection across north TX to the Red River. However, elevated storm development appears more probable overnight from north TX/southern OK to the Arklatex and northern LA, with profiles favorable for elevated supercells with large hail. ...LA to the FL Panhandle/south GA this afternoon/evening... Some convection is ongoing across north FL and could continue southeastward as the low levels warm/destabilize south of the anvil shading. Farther west and north, surface heating is underway in advance of a cold front from central GA westward across southern AL/MS into LA near I-20. The combination of weak convergence/ascent along the front, as well as along the sea breeze, will support scattered thunderstorm development by early-mid afternoon. Seasonably large buoyancy (MLCAPE in excess of 3000 J/kg) and somewhat stronger-than-normal westerly flow aloft and resultant vertical shear will support the potential for multiple storm clusters and a few supercells capable of producing damaging outflow winds and large hail for several hours this afternoon/evening. ....Southeast CO/northeast NM this afternoon/evening... Moist upslope flow persists from northeast NM into southeast CO, and convection has been persistent across this area since last night (in the zone of ascent downstream from an embedded speed max over NM). Clouds will tend to slow surface heating, but relatively rich moisture into the higher terrain and robust west-southwesterly flow aloft will support a few supercells with large hail of 1-2 inches in diameter this afternoon through this evening. ....Mid-Atlantic to NC this afternoon... A closed midlevel low persists over the Great Lakes, and to its south and southwest, a relatively strong subtropical branch of the westerlies extends from the southern Rockies to the northern Gulf Coast states. In association with an embedded shortwave trough rotating around the southeast periphery of the Great Lakes low, a surface cyclone will pivot northward across western PA/NY and occlude over southwest ON. A trailing cold front will move eastward across the Mid-Atlantic this afternoon through late evening, providing a focus for scattered thunderstorm development. Surface heating east of the thicker clouds over VA/MD and a modest increase in midlevel flow will support the potential for a few storms with damaging outflow gusts this afternoon from southern NJ/southeastern PA to eastern NC. $$ = = = 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) .