Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat May 24 2025 12:47:09 AWUS01 KWNH 241245 FFGMPD TNZ000-MSZ000-MOZ000-ARZ000-OKZ000-KSZ000-241800- Mesoscale Precipitation Discussion 0308 NWS Weather Prediction Center College Park MD 844 AM EDT Sat May 24 2025 Areas affected...Southeast KS and Eastern OK through the Ozarks Concerning...Heavy rainfall...Flash flooding possible Valid 241244Z - 241800Z Summary...A sprawling MCS aligned north of a warm front will continue to dig southeast this morning while only slowly weakening. Rainfall rates of more than 2"/hr are likely at times, leading to 1-3" of rain with localized amounts above 4". This could cause instances of flash flooding. Discussion...The regional radar mosaic this morning shows a large swath of convection aligned WNW to ESE from southeast Kansas through the Ozarks and into western Tennessee. This convection is generally formed along the nose of a LLJ that is measured via regional VWPs of 30-35 kts from the SW, feeding into the clusters of thunderstorms to continue to fuel heavy rainfall rates estimated via local WSR-88Ds of 2-3"/hr at times. This convection is persisting just north of a warm front, so the LLJ is additionally lifting isentropically to produce ascent beyond the convergence along the nose of the LLJ. Additionally, an MCV is noted in the reflectivity moving into NW AR, with the accompanying convergence boundaries providing an additional impetus for strengthening areas of thunderstorms, although a bow echo developing Over the next few hours, the high-res CAMs are in good agreement that the developing bow echo will become the dominant feature as the LLJ begins to veer more out of the west, helping to sweep out the remaining convection from northwest to southeast. While this will result in faster general motion and a slow reduction in the flash flood potential, it will take several hours for everything to propagate southeast out of the area. Additionally, a convergent trailing tail west of this MCV/bow echo, noted already on reflectivity across SE KS, could result in some backbuilding and lingering heavy rainfall, despite more modest instability. Rainfall rate forecasts from the HREF and 15-min HRRR continue to indicate that 2"/hr or more are likely as everything dives southeast, although the heavier rates will likely be within the faster moving cells. Otherwise, there are moderate probabilities (20-40%) for rates exceeding 1"/hr along the convergent bands, and additional rainfall of 1-3" with locally more than 4" is expected. 3-hr FFG across this area is generally 2-4", for which the HREF has a decreasing trend in potential for exceeding through late morning. However, where the rainfall rates are strongest near the MCV, or where multiple rounds can occur within the WAA downstream of the MCV/along any convergent bands, both the HREF and REFS suggest a 10-20% chance of exceedance, further indicating the continued potential for at least additional isolated flash flooding into the early aftn. Weiss ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6twk8jaOYHowMlLwgESbuWirvoheBtWy26KWmZ3uLSFlTLJ8xh05itsuqM3PWkcVx8zf= Rjq_28bfv2BlMm-ZNhoVFW4$ for graphic product... ATTN...WFO...ICT...LZK...MEG...OUN...PAH...SGF...SHV...TSA... ATTN...RFC...KRF...ORN...TUA...NWC... LAT...LON 38129793 37889672 37559548 37349414 37049223=20 36409057 35698979 34998938 34478944 34288987=20 34279055 34309136 34449239 34369322 34239414=20 34179495 34649580 35409653 36499697 37669796=20 =20=20=20=20=20=20=20=20=20=20=20=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) .