Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Mar 11 2023 13:00:30 ACUS01 KWNS 111300 SWODY1 SPC AC 111258 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0658 AM CST Sat Mar 11 2023 Valid 111300Z - 121200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN OKLAHOMA AND ARKANSAS/FAR NORTHWEST MISSISSIPPI... ....SUMMARY... Scattered severe thunderstorms capable of large hail will be possible this evening and overnight especially across eastern Oklahoma, Arkansas, and northern Mississippi. ....Eastern Oklahoma/ArkLaTex to Northern Mississippi... Gradual/modest mid-level trough amplification will occur over the south-central Plains and Ozarks through tonight, somewhat mirroring a more substantial trough over the northern Plains and Upper Midwest. Related to a southeastward-moving cold front, a surface wave will shift southeastward from the southern High Plains toward the southern Oklahoma/northern Texas Red River vicinity, while a warm front and related warm sector shifts and expands northeastward toward eastern Oklahoma and the ArkLaTex/ArkLaMiss regions. Given this scenario, the latest short-term guidance suggests that lower 60s surface dew points will surge to near I-40 over eastern Oklahoma just prior to the wind shift. As the low is shunted southeast to near the Red River, strong surface heating ahead of the front will result in a plume of steep low-level lapse rates spreading across northwest Texas into south-central Oklahoma. Forecast soundings suggest inhibition will be negligible by 22z as surface temperatures warm into the lower-mid 80s immediately behind the dryline. Convection may struggle for a few hours given the expected veered low-level flow; however, deep convection should root into the increasingly moist boundary layer across eastern Oklahoma, possibly by around sunset or shortly thereafter. Accentuated by 50+ kt mid-level westerlies, 40-55 kt effective shear will favor supercells, and forecast soundings exhibit substantial SBCAPE (in excess of 2000 J/kg) and steep lapse rates. Current thinking is isolated supercells should develop ahead of the cold front/dryline over Oklahoma and then mature as they track east-southeast toward southern/central Arkansas. Very large hail is possible with some of this activity. Farther south-southwest into northeast/north-central Texas, forecast soundings exhibit minimally capped surface parcels in vicinity of the dryline, well to the south of the primary influence of the shortwave trough/height falls. While profiles suggest that convection is possible, it is not entirely clear whether updrafts will sustain along southern portions of the dryline within a weakly forced environment. Most available guidance suggest that deep-convective potential should remain limited across this region, although multiple recent runs of ECMWF provide comparatively more bullish indications of convective potential across northeast Texas by early/mid-evening. ....Southwest States... A belt of strong/low-amplitude westerlies coupled with steep lapse rates and modest moisture could yield a couple of stronger storms late this afternoon/early evening across the California San Joaquin Valley and/or across southern Nevada into southern Utah/far northern Arizona. However, organized severe storms are not currently expected. ...Guyer/Broyles.. 03/11/2023 $$ = = = 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) .