Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Mar 16 2023 13:01:08 ACUS01 KWNS 161301 SWODY1 SPC AC 161259 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0759 AM CDT Thu Mar 16 2023 Valid 161300Z - 171200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS SOUTHERN OKLAHOMA/NORTH TEXAS AND FAR SOUTHWEST ARKANSAS... ....SUMMARY... Scattered severe thunderstorms capable of producing large hail, damaging winds, and a few tornadoes are likely this afternoon and evening across parts of the southern Plains. Some of the hail could be very large over southern Oklahoma and north-central Texas. ....Southern/Eastern Oklahoma and Central/North Texas... Emerging from split flow over the West, a low-amplitude shortwave trough and mid/high-level speed max centered along the Arizona/New Mexico/International border vicinity early this morning will steadily influence the region into mid/late afternoon. Low-level moisture will stream north-northeastward today, with lower 60s F surface dewpoints quickly becoming established into southern/eastern Oklahoma and the ArkLaTex, and middle 60s F across central/east Texas. This will be to the east of a surface trough/dryline, and to the southeast of a cold front that will steadily progress southeastward and overtake the dryline from north to south through tonight. Within the warm sector, diurnal heating will promote moderate to locally strong destabilization with MLCAPE of 1500-2500 J/kg in the presence of relatively steep mid-level lapse rates. Effective shear will increase into the 40-60 kt range as strong mid-level flow overspreads the region. With the relatively early arrival of strong forcing for ascent and cooling aloft reaching the cold frontal vicinity/nearby warm sector, strong to severe thunderstorms could develop near the advancing front by early afternoon across southwest into central/south-central Oklahoma. Subsequent additional development can be expected southward into North Texas into late afternoon in vicinity of the dry line, some of which could be semi-discrete in advance of the upstream cold front. The initial frontal storms and any discrete development across the warm sector should quickly evolve into supercells across southern Oklahoma and north-central Texas, with a threat of very large hail and isolated severe wind gusts. Effective SRH of 200-400 m2/s2 will support a tornado threat (including a conditional risk for a strong tornado) with any sustained warm-sector supercells that can avoid being undercut by the front. ....Central/South-Central Texas... The potential for pre-frontal storm development is more uncertain with southwestward extent into south-central Texas, with this area being further removed from the ejecting shortwave trough. However, any discrete supercell development along the pre-frontal trough or the front itself would quickly pose a threat of large hail and isolated severe gusts. Storm coverage will increase with time along the front tonight. While there will be a tendency for storms to be undercut by the front in this area, the strongest updrafts may still be accompanied by hail and isolated strong/severe wind gusts. ....ArkLaTex to Lower Mississippi Valley... Near the warm front or within the warm sector, there is some potential that a supercell or two could develop out of initially elevated convection across the ArkLaTex region late this afternoon/early evening. However, lingering cloud cover seems likely to temper insolation/low-level lapse rates to a degree, which would make discrete surface-based development less likely prior to the upstream near-cold frontal convective regime that will be regionally inbound from northwest to southeast this evening. Thus, while an isolated supercell/severe risk may exist late this afternoon, severe potential will become more probable toward/after 00z, although a weakening trend is expected overnight as storms move into a less unstable environment. Some threat for locally damaging winds and/or a brief tornado may extend as far east-southeast as the lower Mississippi Valley through 12Z Friday morning. ...Guyer/Broyles.. 03/16/2023 $$ = = = 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) .