Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jun 20 2023 03:40:52 AWUS01 KWNH 200340 FFGMPD LAZ000-200640- Mesoscale Precipitation Discussion 0533 NWS Weather Prediction Center College Park MD 1140 PM EDT Mon Jun 19 2023 Areas affected...Southeast LA Concerning...Heavy rainfall...Flash flooding likely Valid 200340Z - 200640Z SUMMARY...A cluster of thunderstorms with extremely heavy rainfall rates continues to advance across areas of southeast LA. Additional flash flooding is likely over the next 2 to 3 hours. DISCUSSION...The latest radar imagery in conjunction with GOES-16 IR satellite continues to show a cluster of strong to severe thunderstorms impacting areas of southeast LA in the vicinity of Lake Pontchartrain and adjacent parishes to the west and northwest. The overall convective cluster has been advancing off to the west as a strong cold pool advances generally in from the east across the central Gulf Coast region. However, many of the individual cells are forming near the LA/MS border where stronger moisture convergence/forcing is noted and then advancing south and southeast over the top of the cold pool. Very strong instability is situated west of the convective cluster over south-central LA with MLCAPE values of as much as 3000 to 4000 J/kg, and this coupled with a very moisture-rich boundary layer advecting east over top of the leading edge of the cold pool should favor additional areas of convection to regenerate in the short-term across portions of southeast LA. Strong vertical shear profiles over the region will be another contributing factor to convective sustenance at least for the next few hours. Given the pattern of cell-training that is occurring, there will continue to be concerns for excessive rainfall amounts. Areas of flash flooding are already occurring to the northwest of Lake Pontchartrain, and the convection may have an opportunity to still impact the New Orleans metropolitan area farther to the south over the next couple of hours as the larger scale convective mass advances westward. Given the latest radar trends, additional areas of flash flooding are likely with some of the storms continuing to produce 2 to 3+ inch/hour rainfall rates. Some additional storm totals may reach 4 to 6 inches in just a 2 to 3 hour period. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!7lORdulyyI77RldINX4H7E8JNRbv9xF-Cm7KaIpMPbSi8crtybxu_nlZm6S-5hO4sEUB= Fm6rQsgfpECwooMymx5Yo1o$ for graphic product... ATTN...WFO...LIX... ATTN...RFC...LMRFC...NWC... LAT...LON 30819092 30739025 30398973 30018950 29678960=20 29548990 29759063 30419124=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) .