Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Apr 09 2024 20:54:13 AWUS01 KWNH 092054 FFGMPD MSZ000-LAZ000-ARZ000-TXZ000-100315- Mesoscale Precipitation Discussion 0141 NWS Weather Prediction Center College Park MD 453 PM EDT Tue Apr 09 2024 Areas affected...Ark-La-Tex into northern LA, southern AR, and west-central MS Concerning...Heavy rainfall...Flash flooding likely Valid 092115Z - 100315Z Summary...Scattered to numerous instances of flash flooding likely with widespread additional totals of 1-2" (and localized totals of 2-4"). Some significant flash flooding is possible. Discussion...An MCS has gained better organization across portions of eastern TX over the past several hours, producing hourly rainfall totals of 1-2" in association with the primary bow echo (per MRMS estimates). The mesoscale environment looks to remain favorable for maintaining the MCS, as a strong (but slowly waning) LLJ transports ample moisture northward from the Gulf the a shortwave trough aloft providing 50-70 kts of deep layer shear. The primary bow echo looks to continue to progress towards the ENE at 40-50 kts, nearly parallel with an associated quasi-stationary surface front (as well as the 850-300 mb mean flow). Backbuilding of convection along the southwestern flank of the MCS will continue to allow for training of heavy rainfall rates, which may lead to hourly totals to reach as high as 3" locally. As a result, some localized 2-4" totals are expected along the southwestern flank of the MCS, favoring areas near and south of Shreveport. Should the bow echo maintain its structure as it travels generally eastward, than these higher totals may extend as far east as northeast LA into the west-central MS (most prominently depicted by the ARW and HRRR solutions). While north-central LA is the most favored corridor for intense convection (directly along the gradient of favorable instability with MU CAPE of 500-1500 J/kg), areas just to the north (from northwest LA into southern AR and the MS Delta) remain the most saturated from prior rainfall (with FFGs generally < 2"). While the MCS should begin to favor a southeast drift (as mature MCSs tend to migrate to the warm side of the stationary front), the northern flank (and possibly north bookend vortex) can still produce very heavy rainfall, resulting in localized hourly totals of 1-2" (but generally limited to 2" due to less favorable training). This will likely result in scattered to numerous instances of flash flooding, given relatively widespread totals of 1-2" (and more localized totals of 3-4"). Given the wet antecedent conditions across much of the region, some significant instances of flash flooding are possible. Churchill ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6oFKE_cGQUPB6DcAShWxNyDVXSOGGebb4O8mLadYOaG8oKHo_tpJ9VYCn32tWdEldqgt= 4qSBKS_Tc-iZ20mJOVwoQUY$ for graphic product... ATTN...WFO...HGX...JAN...LCH...LZK...MEG...SHV... ATTN...RFC...LMRFC...WGRFC...NWC... LAT...LON 34309061 32988997 31989082 31049376 31259500=20 32089489 32629493 32749433 32969415 33349382=20 33639249=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) .