Subj : DAY3SVR: Nws Storm Prediction Center Norman Ok To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Dec 06 2023 07:45:54 ACUS03 KWNS 060744 SWODY3 SPC AC 060743 Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0143 AM CST Wed Dec 06 2023 Valid 081200Z - 091200Z ....THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE OZARKS TO FAR NORTHEAST TEXAS... ....SUMMARY... Isolated severe thunderstorms will be possible Friday night across parts of the Ozarks to the Red River Valley of southeast Oklahoma and northeast Texas. ....Ozarks to northeast TX... An amplifying shortwave trough over the Great Basin on Friday morning will progress southeast across the Four Corners to the southern High Plains by early Saturday. A surface low initially over the TX Panhandle vicinity should move east towards the Ozark Plateau, along a sharpening front that will accelerate southeast Friday night as surface high pressure builds over the West. While most guidance is fairly consistent on the synoptic scale with some mesoscale differences becoming more apparent by Friday night, the primary uncertainty is with the degree of instability ahead of the aforementioned frontal wave. The 00Z NAM appears to be an outlier among deterministic guidance with its typical cold/saturated bias apparent in the 0-1 km layer, while the GFS is on the more aggressive end of the spectrum relative to the GEFS. With substantial modification necessary of the CP air mass that is currently across all but Deep South TX, guidance may be a bit too aggressive with the northward extent of surface-based instability given the positive-tilt orientation and timing of the amplified shortwave trough. Both the NAM and to some extent ECMWF forecast soundings suggest substantial mid-level dry air will be prevalent within the southwest flow regime, and at least a modestly capped warm sector. As such, low confidence exists in whether surface-based convection can develop prior to 12Z Saturday. The most likely scenario appears to be elevated thunderstorms increasing in coverage Friday night within the low-level warm conveyor, as mid-level height falls gradually overspread the region. This activity should pose a threat for at least isolated severe hail. ...Grams.. 12/06/2023 $$ = = = 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) .