Subj : DAY2SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Nov 18 2023 17:24:27 ACUS02 KWNS 181724 SWODY2 SPC AC 181722 Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1122 AM CST Sat Nov 18 2023 Valid 191200Z - 201200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS SUNDAY NIGHT ACROSS PARTS OF CENTRAL INTO NORTHEASTERN OKLAHOMA... ....SUMMARY... A couple of strong thunderstorms may develop across parts of central into northeastern Oklahoma Sunday evening, accompanied by a risk for small to marginally severe hail. ....Synopsis... Amplification within the westerlies across the mid-latitude eastern Pacific into western North America appears gradually underway. Through Sunday/Sunday night, this is forecast to include building mid-level ridging across the U.S. and Canadian Pacific coast. Downstream, though there remains considerable spread concerning smaller-scale short wave developments, models indicate that large-scale troughing will continue to evolve across the eastern Great Basin and southern Rockies through Mississippi Valley vicinity, with a broad embedded mid-level low evolving across the central Great Plains by 12Z Monday. It appears that this regime will be accompanied by at least modest surface cyclogenesis, generally from southeastern Colorado into the Red River Valley vicinity. In the wake of ongoing low-level cooling/drying across much of the Gulf of Mexico (associated with mid-level troughing now digging off the south Atlantic coast), however, low-level moisture return within the evolving warm sector is forecast to remain relatively modest. Coupled with initially weak lower/mid-tropospheric lapse rates to the lee of the southern Rockies, the potential for widespread, substantive destabilization and strong thunderstorm development appears limited through this period. ....Great Plains... It does appear that elevated moisture return may contribute to thermodynamic profiles sufficient for convection capable of producing lightning, in an arcing band across southwestern Nebraska through central Kansas by the beginning of the period. Guidance suggests similar convective development with increasing potential to produce lightning shortly thereafter, across parts of northwestern Texas into the Red River Valley. This activity likely will be supported by a couple of initial short wave perturbations progressing to the east of the southern Rockies, and may tend to shift with better lingering forcing for ascent into southeastern Kansas/eastern Oklahoma and perhaps northeastern Texas through late Sunday afternoon. By Sunday evening (after 20/00Z), models suggest that strengthening differential thermal advection to the east-northeast of the surface cyclone may contribute to sufficient steepening of mid-level lapse rates to support CAPE increasing in excess of 500 J/kg. Although stronger mid/upper forcing for ascent is forecast to remain to the cool side/above the strengthening warm front, the environment might become conducive for a few strong storms posing a risk for marginally severe hail, generally near/north-northeast of Oklahoma City into the Tulsa vicinity. ...Kerr.. 11/18/2023 $$ = = = 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) .