Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Jun 15 2023 07:31:06 ACUS03 KWNS 150731 SWODY3 SPC AC 150730 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0230 AM CDT Thu Jun 15 2023 Valid 171200Z - 181200Z ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS SATURDAY THROUGH SATURDAY NIGHT ACROSS PARTS OF SOUTHERN KANSAS...SOUTHWESTERN MISSOURI...NORTHWESTERN TEXAS...MUCH OF OKLAHOMA AND NORTHWESTERN ARKANSAS... ....SUMMARY... Severe thunderstorms are possible across portions of the central and southern Great Plains Saturday through Saturday night, with additional strong to severe thunderstorm development possible near the eastern Gulf coast. ....Synopsis... Seasonably moist air supportive of large CAPE may become confined to the Gulf coastal plain into central Texas and the Texas South Plains by early Saturday, generally along and south of a conglomeration of convective outflow, and perhaps, a remnant surface front. From near the lower Mississippi Valley through much of the southern Great Plains, it appears that this will be located beneath mid-level ridging extending to the north of an initially prominent subtropical high centered near the lower Rio Grande Valley. Models have varied considerably over the past several days concerning the strength of the mid-level ridging over the southern into central Great Plains. However, latest model output, particularly the deterministic guidance, appears to be trending toward more substantial weakening of this ridging during this period. As a strong, initially zonal mid/upper flow over the northeastern mid-latitude Pacific begins to amplify southeastward into British Columbia and the Pacific Northwest, it appears that much less prominent preceding mid-level perturbation will accelerate east-southeastward from the Great Basin. It now appears that this lead mid-latitude impulse may contribute to substantive mid-level height falls across the Texas/Oklahoma Panhandle, and perhaps Texas South Plains, by late Saturday afternoon, through much of the south central Great Plains by 12Z Sunday. This will be preceded by one impulse of subtropical eastern Pacific origins, which may weaken across the central Great Plains through lower Missouri Valley, and another convectively enhanced subtropical perturbation digging through the eastern Gulf Coast states. The lead impulse may contribute to further amplification of mid-level troughing off the south Atlantic Seaboard, while a modest cyclone in a separate branch of westerlies to the north slowly migrates northeastward along the New England coast. ....Southern Great Plains... A dryline across parts of west Texas and the Texas South Plains into the Texas Panhandle may become one focus for strong thunderstorm initiation by late afternoon, while a warm frontal zone, near the northern periphery of initially warm and more strongly capping elevated mixed-layer air, becomes another focus near the Kansas/Oklahoma border vicinity into the Ozark Plateau. With higher moisture content air tending to be suppressed east and south of these boundaries, it appears that CAPE supporting initial thunderstorm development may be more modest than preceding days. However, in the presence of a belt of seasonably strong westerly mid-level flow overspreading the region, deep-layer shear will still be supportive of supercell development initially, then gradual upscale growing, east-southeastward propagating clusters. This will be accompanied by a risk for large hail and perhaps a couple of tornadoes, before strong wind gusts become the more prominent potential hazard before convection weakens Saturday night. ....Lower Mississippi Valley into eastern Gulf Coast... Convective potential will largely be determined by where the conglomerate convective outflow ends up by early Saturday, in addition to the strength and progression of the convectively enhanced mid-level perturbation and wind fields. This remains uncertain at this time, but it still appears possible that there may be a lingering corridor of large CAPE and sufficient shear to support a risk for organized severe thunderstorm development Saturday into Saturday evening. ...Kerr.. 06/15/2023 $$ = = = 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) .