Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri May 19 2023 06:02:12 ACUS01 KWNS 190602 SWODY1 SPC AC 190600 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0100 AM CDT Fri May 19 2023 Valid 191200Z - 201200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE SOUTHERN PLAINS INTO WESTERN ARKANSAS... ....SUMMARY... Strong/locally severe storms are expected this afternoon and evening from parts of the southern Plains eastward into parts of Arkansas. ....Synopsis... A rather deep mid/upper-level cyclone is forecast to move across the Great Lakes region today, as an associated cold front moves southward through parts of the central/southern Plains, lower/mid MS Valley, and OH Valley. An upper ridge is expected to remain in place over parts of the Great Basin. A weak mid/upper-level trough is expected to move northeastward near the Carolina coast, with development of a surface low possible along the coastal front later today into tonight. ....North TX into central/southeast OK and western AR... An overnight MCS is expected to weaken later this morning across parts of OK. The evolution of the associated MCV and any outflow boundaries remain somewhat uncertain, but in general, moderate destabilization is expected along/south of the cold front this afternoon from parts of OK into the ArkLaTex region and much of TX. The cold front will likely be the primary focus for scattered thunderstorm development by late afternoon, though initiation will also be possible near any remnant outflow boundary, and some guidance suggests development near a prefrontal trough across parts of north TX. Deep-layer flow will not be particularly strong, but some modest enhancement to midlevel westerlies associated with the MCV may support effective shear of 30-35 kt across parts of OK into north TX, supporting the potential for strong multicell clusters and perhaps a couple of supercells. Guidance varies somewhat regarding the strength of low-level flow/shear across the warm sector, but a tornado or two cannot be ruled out if supercells can be sustained. ....Southeast NM into parts of west-central/southwest TX... A surface trough and associated wind shift is expected to move southward into parts of southeast NM/west TX during the afternoon, well in advance of the relatively cold/stable airmass moving southward across the Great Plains. Isolated to widely scattered thunderstorm development will be possible along/north of this surface trough, within a warm/well-mixed environment. North/northeasterly surface winds veering to modest westerlies aloft will support effective shear of 30-40 kt, and a few organized cells/clusters capable of hail and isolated severe gusts will be possible. A loosely organized MCS may develop and spread southward across the Edwards plateau later tonight, with a continued risk of at least isolated severe wind/hail. ....OH Valley into the lower Great Lakes... Modest heating/moistening may support weak convection along the cold front this afternoon/evening across parts of the OH Valley and lower Great Lakes region. While wind profiles will be somewhat supportive of organized storms, very weak buoyancy is expected to limit the overall severe risk. ....Arizona... Scattered to widespread thunderstorms are expected across parts of AZ this afternoon and evening, within an anomalously moist environment. Weak northeasterly midlevel flow may support an outflow-driven storm cluster moving into the lower elevations with gusty wind potential, though any severe wind risk remains uncertain at this time. ...Dean/Thornton.. 05/19/2023 $$ = = = 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) .