Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue May 20 2025 00:45:33 AWUS01 KWNH 200045 FFGMPD MOZ000-IAZ000-KSZ000-NEZ000-200430- Mesoscale Precipitation Discussion 0291 NWS Weather Prediction Center College Park MD 844 PM EDT Mon May 19 2025 Areas affected...northeast KS, northwest MO, south-central IA, and far southeast NE Concerning...Heavy rainfall...Flash flooding likely Valid 200040Z - 200430Z Summary...Continued thunderstorms (up to 1-2"/hr rates) within the warm sector of a nearby low pressure system will likely result in additional localized 2-4" totals through 0430z (1130 PM CDT). Scattered to numerous instances of flash flooding are likely (and may locally be significant in the vicinity of the Kansas City metro area). Discussion...Thunderstorms are once again expanding in coverage once again across portions of eastern KS, this time a bit farther west closer to the dryline (which is in the process of being overtaken by a lagging cold front). While much of the earlier convection has progressed north and east since the prior MPD, rainfall totals over the past 4 hours have been locally as high as 1.5-5.0" (with the highest totals near and immediately north and northeast of the KC metro, where MRMS FLASH CREST unit streamflow indicating ongoing minor to moderate flooding, which has been gradually subsiding). Despite the earlier convection, the mesoscale environment remains supportive of heavy rainfall, with MLCAPE of 500-2500 J/kg, PWATs of 1.3-1.7 inches (above the 90th percentile, per TOP sounding climatology), and highly anomalous deep layer (0-6 km) shear of 50-60 kts. The recent convection along the dryline has been much slower to advance with localized backbuilding, but should start to propagate upwind (towards the ENE-E at 20-30 kts) as cold pools becoming more established (and eventually by the synoptic forcing of the cold front).=20 The expectation is for localized 1-2"/hr rates to continue in this favorable environment, given observational trends and recent hi-res model data. This convection is likely to pass over the same areas that have recently received heavy rainfall, and may even locally train/repeat as well (as the mean 850-300 mb flow remains parallel to the dryline and ongoing convection). This should result in additional localized totals of 2-4" (as indicated consistently by runs of the HRRR since 20z, as well as the 50th percentile of accumulated rainfall from the experimental WoFS). Given 3-hr Flash Flood Guidance (FFG) of 2.0-3.0" (which largely doesn't take into account the recent rainfall), scattered to numerous instances of flash flooding are likely. Churchill ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9vU_1Bw_WMlQLx0iMhaVTtrRKejjusIpoBJ-iLLr8HAXIAkd_EasNV5PsQqt3g_G_hgM= ZaES5oTOrL7-2gSiWQ9L-TY$ for graphic product... ATTN...WFO...DMX...EAX...ICT...OAX...TOP... ATTN...RFC...ABRFC...MBRFC...NCRFC...NWC... LAT...LON 41779594 41729509 41499419 40829308 40249281=20 39219325 38399442 37769665 38329694 39449642=20 40339680 40939678 41549652=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) .