Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Mar 14 2024 19:38:51 ACUS01 KWNS 141938 SWODY1 SPC AC 141937 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0237 PM CDT Thu Mar 14 2024 Valid 142000Z - 151200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM NEAR THE RED RIVER NORTHEASTWARD ACROSS THE OZARKS... ....SUMMARY... Large damaging hail, wind gusts, and a few tornadoes are expected from far northeast Texas to the Ohio Valley. ....Northeast TX/Eastern OK to the Mid MS/OH Valley region... A large area of severe storm potential exists today due to a expanding plume of instability, beneath strong westerlies. Scattered severe storms are currently ongoing over eastern OK, and as far south as the Red River. This region is characterized by strong instability and deep-layer shear, but relatively weak low-level shear. As such, large hail will continue to be the primary concern. However, a brief tornado may still occur with complex storm/outflow interactions. Farther north, stronger low level shear currently exists from central MO eastward across the OH Valley. Winds aloft in this region are more westerly than southwesterly, resulting in rightward motion and better low-level SRH. The area will continue to destabilize, and scattered supercells are likely to develop soon over much of MO and IL. Very large hail is likely with the strongest storms, and a couple tornadoes may also occur where 0-1 SRH exceeds 100 m2s/2. Veering low-level winds may tend to truncate low-level shear a bit, trending toward straight-line hodographs. However, any rightward-turning supercell should thrive in the diurnally favorable and unstable environment, possibly with tornado threat. Finally, a lone supercell, tornadic at times, persists on the nose of the low-level theta-e plume over northern KY. This cell is near the instability gradient, and may persist. For more information on this area see mesoscale discussion 233. ...Jewell.. 03/14/2024 ..PREV DISCUSSION... /ISSUED 1130 AM CDT Thu Mar 14 2024/ ....Missouri eastward into Kentucky/Indiana/Ohio... A complex scenario is unfolding for today, given rather subtle large-scale ascent across much of the area, but with a very favorable background thermodynamic environment coupled with strong deep-layer shear. A line of strong/locally severe storms is ongoing this morning across Indiana, which will continue eastward this afternoon into Ohio. Locally damaging wind gusts will be the primary risk with these storms, continuing across western Ohio before some weakening eventually occurs given weakening instability with eastward extent into the upper Ohio Valley. In the wake of these storms, but ahead of a sagging cold front, airmass recovery is underway. Clouds have cleared across Illinois and for the most part Missouri as well, ahead of the front and in the wake of earlier storms. Ongoing heating, beneath steep lapse rates aloft, will result in a moderately unstable warm sector this afternoon. CAMs continue to suggest redevelopment of more cellular -- eventually clustered -- convection across this region this afternoon, and eventually (presuming ample airmass recovery can occur) into Indiana and possibly/eventually western Ohio. Though low-level flow behind the initial band of Indiana storms will likely remain somewhat veered, which may limit more substantial tornado risk, very large hail is expected, along with damaging winds and a couple of tornadoes. Storms could eventually grow upscale this evening, spreading across the Tennessee Valley region accompanied by continued severe risk. ....North Texas and the eastern half of Oklahoma to the Mid Mississippi Valley area... Storms have developed rapidly over the past hour across portions of far northern Texas and into south-central Oklahoma near the slowly advancing front/dryline, where heating beneath steep mid-level lapse rates has resulted in development of 2000 to 2500 J/kg mixed-layer CAPE. With 50 kt mid-level southwesterlies across the region, deep-layer shear is supportive of updraft rotation, and thus associated potential for very large hail, along with locally severe wind gusts. Low-level southerlies are contributing to sufficient shear for a couple of tornadoes late this morning/early this afternoon. However, gradual veering, and some weakening, of the low-level wind field is expected, which should temper tornado risk to some degree. Still, a couple of tornadoes are expected with stronger/sustained supercells. With time, severe/supercell storms will spread eastward across the Ozarks/Arklatex, likely clustering to some degree into this evening, though with supercell structures persisting. Very large hail, locally damaging wind gusts, and potential for a couple of tornadoes will continue, eventually reaching the Mid-Mississippi Valley area. A few CAMs continue to suggest potential for overnight development of storms across portions of central Texas, potential slightly elevated atop of a slightly stable boundary layer. Given sufficient shear and the steep lapse-rate environment, conditional risk for very large hail remains evident. $$ = = = 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) .