Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu May 11 2023 15:28:10 AWUS01 KWNH 111528 FFGMPD MSZ000-LAZ000-ARZ000-TXZ000-112125- Mesoscale Precipitation Discussion 0262 NWS Weather Prediction Center College Park MD 1127 AM EDT Thu May 11 2023 Areas affected...northern LA, western MS and central/eastern AR Concerning...Heavy rainfall...Flash flooding likely Valid 111525Z - 112125Z SUMMARY...Areas of flash flooding, some significant, will remain likely across portions of northern LA, with the threat extending into western MS and portions of AR through 21Z. Additional rainfall maxima through 21Z are expected to range from 4 to 6 inches, although isolated 6+ inch totals cannot be ruled out. DISCUSSION...1445Z radar imagery showed that areas of heavy rain continued to impact portions of AR into northern LA with the greatest training of cores having moved out of eastern TX into northwestern LA. An MCV/secondary vorticity max was noted via radar imagery along the Red River/Bienville Parish border, tracking ENE with a west to east axis of training in its wake, containing MRMS-derived rainfall rates of 2-3 in/hr. Farther north into AR, low level confluence was helping to support an axis of slow moving heavy rain, out ahead of a primary vorticity max over northwestern AR, gradually shifting off toward the east with peak rainfall rates generally between 1-2 in/hr. As the MCV/secondary vort max continues to translate toward the ENE toward MS, 25-35 kt of 925-850 mb will continue to support an axis of convergence over northern LA, with areas of training likely to continue from west to east, although there is some potential for the leading edge of heavier rain to bow toward the southeast. Still, the western/southwestern portion of the line is expected to experience periods of training and peak rainfall rates of 2-3 in/hr are expected. Redevelopment of convection will also be also possible along the Sabine River as the main precipitation shield moves into western MS given the low level influx of moist/unstable air from the south. Additional rainfall totals through 21Z are expected to range between 4-6 inches, but some locally higher totals cannot be ruled out. These totals could lead to areas of significant flash flooding, especially if there is overlap with any urban corridors. Farther north into AR, as the low level confluence axis shifts toward the east, rainfall rates of 1-2 in/hr will continue at times within an environment forecast by the RAP to have 500-1000 J/kg MLCAPE available. For locations in AR and portions of MS, additional peak rainfall totals of 2-4 inches are expected, which will continue the flash flood threat for these locations as well as LA. Otto ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5WFh0VucCA6WOSuyzP4rzFog-xXvlwtbAgemMU1ObPmrh3u2hrI3JXf5eI9kjTRzrW6F= A4JSczxz7MBSHCtA9KcOAKg$ for graphic product... ATTN...WFO...JAN...LCH...LIX...LZK...MEG...SHV... ATTN...RFC...ABRFC...LMRFC...WGRFC...NWC... LAT...LON 36349274 36319150 35129064 33099010 31819021=20 30759111 30879287 31789388 32239400 32819387=20 33169359 33919309 35249282=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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .