Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Dec 13 2022 16:31:33 ACUS01 KWNS 131631 SWODY1 SPC AC 131629 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1029 AM CST Tue Dec 13 2022 Valid 131630Z - 141200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS TODAY AND TONIGHT FROM EAST TEXAS TO PARTS OF LOUISIANA AND MISSISSIPPI... ....SUMMARY... Tornadoes (some strong), severe gusts and sporadic large hail are possible from southern Oklahoma and north and east Texas, to parts of Louisiana and Mississippi. ....Synopsis... A 100 knot mid-level jet across West Texas this morning will advance across the Plains and into the Upper Midwest by tonight. At the surface, an area of low pressure will slowly move from northwest Kansas to eastern Nebraska. An occluded front extends from the surface low across northwest Kansas to southeast Oklahoma where it intersects with a warm front. Currently this warm front is oriented more north/south, extending to near Lake Charles, Louisiana, but is expected to orient more northwest/southeast through the day as low-level winds veer. As this occurs, mid to potentially upper 60s dewpoints will advance inland and lead to a more broad warm sector through the day. ....Eastern Texas across central/northern Louisiana... A combination of QLCS and supercell type tornadic circulations have occurred within and slightly ahead of a squall line across southern Oklahoma and north Texas this morning. The northern extent of the threat across southeast Oklahoma has started to wane as the line is being cut off from the better low-level moisture. However, the threat is expected to persist through the morning and early afternoon across northeast Texas where mid 60s dewpoints are already in place and expected to increase through the day amid strengthening low-level flow. The greatest threat will be this evening into the overnight hours from east Texas across Louisiana and into western Mississippi. There is considerable agreement among 12Z CAM guidance for supercells to develop within the uncapped warm sector across east Texas and central Louisiana this afternoon and evening. Most forecast soundings show high temperatures in the 72-73F range at KPOE late this afternoon. However, given at least some broken nature to the upstream cloudcover, would expect temperatures in the mid 70s to be more common. This would lead to MLCAPE in excess of 1500 J/kg south of the warm front. This instability paired with strong low-level shear would pose a threat for strong tornadoes through the afternoon and evening across central Louisiana. ....Eastern/southeastern Louisiana into southwest Mississippi... Late tonight, the cold front is expected to slow across eastern Louisiana with the majority of convection becoming pre-frontal. Despite unfavorable diurnal timing, MLCAPE of 1000 to 1500 is expected to persist as cooling temperatures aloft continue to overspread low-level moisture advection off of the Gulf of Mexico. In addition, an uptick in warm sector storm coverage may occur as some guidance indicates a weak meso-low to develop off the Gulf of Mexico. Favorable hodographs are expected to persist through the overnight period and therefore a tornado threat should continue. An upgrade to higher probabilities was considered due to the expectation for warm sector supercells to develop amid favorable hodographs and a STP of 3-4. However, slightly stronger instability would have been preferred to initiate an upgrade. ...Bentley/Hart.. 12/13/2022 $$ = = = 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) .