Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Dec 27 2024 05:02:00 AWUS01 KWNH 270501 FFGMPD MSZ000-LAZ000-ARZ000-271100- Mesoscale Precipitation Discussion 1196 NWS Weather Prediction Center College Park MD 1201 AM EST Fri Dec 27 2024 Areas affected...Southwest and Central LA...Western and Central MS Concerning...Heavy rainfall...Flash flooding possible Valid 270500Z - 271100Z SUMMARY...A broken axis of heavy showers and thunderstorms will continue to foster a localized threat for some flash flooding overnight across portions of southwest to central LA through western and central MS. DISCUSSION...The latest GOES-E IR satellite imagery shows a vigorous shortwave trough and compact low center transiting the Lower MS Valley which continues to foster a rather well-organized, but broken axis of heavy showers and thunderstorms. The activity has waned somewhat over the last couple of hours as the stronger mid and upper-level dynamics begin to lift away from the area of greater instability pooled closer to the Gulf Coast, but the low-level flow remains rather strong and convergent. In fact, the area VWP data continues to show a 40 to 50+ kt low-level jet surging northward up toward the Mid-South from the Gulf Coast and this is maintaining a corridor of strong moisture transport and convergence along and just ahead of a cold front. MUCAPE values of 1000 to 1500 J/kg are still noted across areas of southwest LA which taper down to 500 to 1000 J/kg across central LA and into far southwest MS. The level of effective bulk shear that is in place remains quite strong and is locally exceeding 50 kts which is still favoring a fair degree of convective organization with the band of thunderstorms including some supercell structures. These stronger cells will continue to have the capability of producing very heavy rainfall rates that will locally reach 1.5 to 2.5 inches/hour, and this will be aided by PWs of near 1.5 inches and the aforementioned low-level jet. The 00Z HREF guidance suggests that some southwest to northeast training of these more organized cells may still occur at least locally going through the overnight hours, with some spotty swaths of 2 to 4 inch rainfall totals possible. As a result, the convective activity is expected to still foster a localized threat for some flash flooding and especially within any of the more urbanized corridors. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8AYKJQYCJzdlGJ1DnlsKVi-y-Vy0y68r4TY_Gx05VUkCCrk_D2j8_DfV9ZoNz4PbNAeT= _RwPP91ja-S6tHrJH66gD4o$ for graphic product... ATTN...WFO...JAN...LCH...LIX...MEG...SHV... ATTN...RFC...LMRFC...SERFC...NWC... LAT...LON 33929018 33838931 33338915 32638945 32049000=20 31549046 30729121 29619243 29509306 29759358=20 30539289 31749210 33299114=20 =3D =3D =3D 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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .