Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jun 18 2023 10:15:52 AWUS01 KWNH 181015 FFGMPD ALZ000-MSZ000-LAZ000-ARZ000-TXZ000-181600- Mesoscale Precipitation Discussion 0518 NWS Weather Prediction Center College Park MD 615 AM EDT Sun Jun 18 2023 Areas affected...Portions of the Lower MS Valley into the Deep South Concerning...Heavy rainfall...Flash flooding possible Valid 181015Z - 181600Z SUMMARY...Multiple rounds of heavy showers and thunderstorms this morning may produce some isolated instances of flash flooding across portions of the Lower MS Valley and adjacent areas of the Deep South. DISCUSSION...The latest radar and satellite imagery shows multiple clusters of strong to locally severe thunderstorms advancing east out of the Red River Valley of the South and through adjacent areas of the Lower MS Valley. This activity is generally rooted along the north side of a strong instability gradient that coincides with a west to east oriented stationary front. The airmass pooled up along and just south of this front remains extremely unstable with MUCAPE values of 3000 to 4000+ J/kg. Meanwhile, PWs along the front are generally as high as 1.75 inches which is being aided in part by the persistence of a southwest low-level jet of 30 to 40 kts. The low-level jet will continue to overrun this frontal boundary over the next several hours and work in tandem with the available instability and strong vertical shear profiles to favor pockets of organized convection. The flow aloft is also quite divergent given proximity of the rather strong mid-level trough/closed low traversing the central and southern Plains which will be heading into the Lower MS Valley by later this morning. Additional rounds of convection are likely to develop and continue to advance rather quickly off to the east across the Lower MS Valley and with a focus farther off to the east into adjacent areas of the Deep South. Areas from far southern AR through central MS and eventually western AL will see the focus of these locally repeating rounds of convection. Rainfall rates with the additional clusters of convection this morning are expected to remain as high as 1 to 2 inches/hour, and given the expectation of seeing multiple rounds of activity, the additional storm totals may reach as high as 3 to 4 inches. Isolated instances of flash flooding will be possible. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5mn66O_a5T73z8cMc6G63b2z1HfLwaM-Da9KLerOzTuxZpCxOniuE3XOsrdvYq4Xmaq-= cjlsltNFBDkQN1uMwki7k2A$ for graphic product... ATTN...WFO...BMX...JAN...LZK...MEG...MOB...SHV... ATTN...RFC...ABRFC...LMRFC...SERFC...NWC... LAT...LON 34219276 34109140 33949000 33508778 32848650=20 31978643 31758749 31948960 32379162 32889349=20 33539423 34109373=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) .