Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Jun 28 2025 19:00:30 AWUS01 KWNH 281900 FFGMPD TNZ000-KYZ000-ILZ000-MSZ000-MOZ000-ARZ000-282300- Mesoscale Precipitation Discussion 0542 NWS Weather Prediction Center College Park MD 300 PM EDT Sat Jun 28 2025 Areas affected...Ozarks Concerning...Heavy rainfall...Flash flooding possible Valid 281859Z - 282300Z Summary...Showers and thunderstorms will continue to expand in coverage and move slowly eastward across the Ozarks and into the Tennessee Valley. This convection will contain rain rates that at times may reach 3"/hr, leading to 2-3" of rain with locally higher amounts. Flash flooding is possible. Discussion...An area of showers and thunderstorms noted on the regional radar mosaic across MO/AR this afternoon is drifting slowly eastward while expanding. Rainfall rates within this convection has been estimated via local radars to be as much as 2.5"/hr (from KSGF), leading to mesonet observed rainfall of 1-2+" so far today. This area of convection is expanding in response to a modest 850mb LLJ of 15-20 kts which is efficiently transporting PWs above 2 inches and MLCAPE as high as 3000 J/kg northward into the region. Additionally, despite modest synoptic lift due to weak flow around a ridge to the south, a weak shortwave approaching from the Central Plains and the convergence of this weak LLJ along its nose are helping to provide just enough ascent in the robust thermodynamics to fuel the widespread activity this aftn. The high-res CAMs are generally under-forecasting the current activity, although the 12Z NAMnest and ARWs appear to have the best handle on the breadth of the current activity. Despite that, the CAMs are likely eroding activity too quickly during the next few hours as the forcing/thermodynamics overlap will support a continuation of this activity well into the Tennessee Valley by this evening. As the favorable PWs and CAPE are continually drawn northeastward, this will support rainfall rates which have a high chance (>70%) of exceeding 1"/hr (from the HREF) with storms slowly moving eastward on 0-6km mean winds of just 5-10 kts. Additionally, weak bulk shear will result in storms manifesting primarily as pulse type, but some weak organization is possible along outflows or in the vicinity of the LLJ nose, leading to some short-term training or backbuilding to prolong these rain rates. Where this occurs, rainfall could be 2-3" or locally higher. FFG across the area is generally 2-3"/3hrs, for which the HREF indicates has a 20-30% chance of being exceeded. However, with the poor overall initiation of the HREF CAMs suite, the true probability is likely higher than this. Additionally, MRMS 24-hr rainfall has been 1 to as much as 3 inches, leading to pockets of fully saturated top-soils which will be more susceptible to runoff. While flash flooding is possible anywhere across the area this aftn, it will be most likely where any short term training can move across the more primed soils. Weiss ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5SyBqEJ3mJ1qmMc5Eh7iEd-U0tFzehTvflgh6ZNNMxQbrvkAStGRN4H4YzKvJOipnNnR= Hq9HQjjzTG1qd1YOGblB2OY$ for graphic product... ATTN...WFO...EAX...LSX...LZK...MEG...PAH...SGF...TSA... ATTN...RFC...KRF...MSR...ORN...TIR...TUA...NWC... LAT...LON 38629272 38369174 37999067 37688938 37438845=20 37068793 36248825 35628906 35108969 34819096=20 35079227 35519309 36269353 36759361 37749371=20 38509336=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) .