Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Nov 12 2022 07:05:57 ACUS03 KWNS 120705 SWODY3 SPC AC 120705 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0105 AM CST Sat Nov 12 2022 Valid 141200Z - 151200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS MONDAY AFTERNOON AND EVENING ACROSS PARTS OF SOUTHEASTERN TEXAS INTO SOUTHERN LOUISIANA... ....SUMMARY... Strong thunderstorms may impact parts of the upper Texas and Louisiana coastal plain Monday afternoon and evening, accompanied by at least some risk for severe weather. ....Synopsis... Models suggest that blocking will become more prominent within the large-scale flow during this period, centered near the North American Pacific coast. It appears that this will include an initial building mid-level high, within larger-scale ridging near the British Columbia/Pacific Northwest coast. The ridge will become flanked by a large, deep mid-level cyclone over the upstream northern mid-latitude Pacific (between 140-160W), and evolving larger-scale downstream troughing across the Rockies into Mississippi Valley vicinity. A vigorous short wave impulse emerging from the Southwest is forecast to become absorbed within the latter regime, accelerating from the southern Rockies at 12Z Monday into the middle Mississippi Valley by 12Z Tuesday. In association with this evolving pattern, cold surface ridging will likely be maintained across much of the U.S. through the period. However, a short-lived return flow of Gulf moisture, above the cold air, may contribute to sufficient elevated destabilization to support a risk for thunderstorms across parts of the southern Great Plains and upper Texas coast vicinity through the central Gulf Coast states. ....Southeast Texas/Southern Louisiana... Although the stronger mid/upper forcing for upward vertical motion may tend to pass to the north of the region, models suggest that a weak low/frontal wave may develop across the upper Texas coastal plain Monday afternoon, along a northward returning low-level baroclinic zone. This might become a focus for at least modest boundary-layer destabilization near immediate upper Texas/southwestern Louisiana coastal areas. Otherwise, NAM forecast soundings indicate that considerable convective instability might develop above a residual shallow stable surface-based layer a bit farther inland across the southeast Texas coastal plain. As a 50-70+ kt westerly mid-level jet overspreads the southern Great Plains, there may be a window of opportunity for the evolution of an environment conducive to organized severe convective development, including supercells, late Monday afternoon and evening. ...Kerr.. 11/12/2022 $$ = = = 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) .