Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Jun 19 2025 05:11:15 AWUS01 KWNH 190511 FFGMPD TNZ000-KYZ000-ALZ000-ILZ000-MSZ000-MOZ000-ARZ000-191030- Mesoscale Precipitation Discussion 0481 NWS Weather Prediction Center College Park MD 110 AM EDT Thu Jun 19 2025 Areas affected...Central/Eastern AR...Central/Western TN...Southwest KY Concerning...Heavy rainfall...Flash flooding possible Valid 190510Z - 191030Z SUMMARY...Some expansion of heavy shower and thunderstorm activity is expected over the next few hours. Some cell-training concerns are expected, and with high rainfall rates, some isolated areas of flash flooding will be possible. DISCUSSION...GOES-E WV suite shows a digging shortwave trough across the Midwest, with the leading edge of height falls impinging on the lower/middle MS Valley. This energy is beginning to interact with a strong instability gradient that is in place across central/eastern AR, western TN and parts of southwest KY. MLCAPE values are on the order of 1500 to 2500 J/kg locally, and despite the negative influence of boundary layer CIN, recent IR satellite imagery shows cooling convective tops becoming better established across eastern AR and into far western TN. A modest southwest low-level jet currently oriented across the region is expected to strengthen and become more convergent over the next few hours and reach 30 to 40+ kts. This will strengthen the moisture transport across the area, but will also foster stronger low-level forcing into an area that is already unstable. A combination of these factors will support some expansion of the current convective activity, with heavy showers and thunderstorms also becoming a bit better aligned with the deeper layer mean flow which will support a cell-training threat. PWs are quite moist with values of 1.8 to 2.0 inches based on 00Z RAOB soundings and recent GPS-derived data. The CIRA-ALPW data shows a substantial level of moisture concentrated in the mid-levels of the column where much of the vertical ascent will be taking place. This suggests convection capable of high rainfall rates that may reach 1.5 to 2.5 inches/hour which is generally supported by the 00Z HREF guidance. However, with the cell-training concerns, some storm totals by dawn may reach 3 to 4+ inches. The HREF guidance does show some low-end FFG exceedance probabilities, and thus the expectation is that some isolated areas of flash flooding will be possible. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6x3IJ-5nN7igBJDozH4IRYtGn08iky7e3IScL7prcbP_D_VoIzRoSIKCel1r5Bk8-U45= iuQXZhYPpLbcCDwcoK7oeuE$ for graphic product... ATTN...WFO...HUN...LMK...LZK...MEG...OHX...PAH... ATTN...RFC...ORN...TIR...TUA...NWC... LAT...LON 37368825 37328650 36598599 35558663 34808852=20 34389048 34589252 35559271 36148994=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) .