Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Sep 23 2025 04:52:43 AWUS01 KWNH 230451 FFGMPD KSZ000-231015- Mesoscale Precipitation Discussion 1121...Corrected NWS Weather Prediction Center College Park MD 1250 AM EDT Tue Sep 23 2025 Corrected for Correction for Areas Affected Areas affected...Western to Central Kansas.... Concerning...Heavy rainfall...Flash flooding possible Valid 230445Z - 231015Z SUMMARY...A highly dynamic environment will support strong moisture flux into a deformation zone resulting in slow moving but efficient rainfall production (rates to 1.75"/hr) resulting in localized spots of 2-3"+ and possible scattered localized flash flooding. DISCUSSION...GOES-E WV shows core of developing larger scale closed low over the Central Rockies with strong undercutting polar jet energy across Colorado into the Central Plains. Simultaneously, the apex of the subtropical jet has reached KS and with broad anticyclonically curved baroclinic shield of cirrus over much of northern KS and southern NEB, with occasional overshooting tops breaking out through the canopy. An older smaller scale shortwave exists in the increasingly divergent portion of northern KS and will meld with southern stream shortwave surging out of the TX/OK panhandles. With all the moving parts in the mid-levels, the surface pattern is lagging a bit being a bit further north for the frontal zone, with a cold front surging down eastern CO, a surface wave in NW KS is slow to advance southeast and with further surge of WAA across south-central into E NEB; this results in a broad conditionally unstable warm sector across much of western and central KS. With the southwesterly surge of low to mid-level flow, the warm conveyor belt/LLJ is strengthening and becoming increasingly convergent across the KS/OK border though is starting to back from southerly to southeasterly as the southwesterly drier air lifts.=20 This is sharpening a shear/stretching deformation zone across west-central KS through toward north-central KS from TQK to HYS to CNK. This will support strong deep layer moisture flux convergence and with ample 1500-2000 J/kg of CAPE will allow for stronger vertical development and potential for rates of 1.5-1.75"/hr, given flux of 1.5" PWs mainly loaded below 700mb.=20 As the 700-500mb low sets up along the lower-level deformation zone, cell motions will be slow and eastward with potential for some mergers/collisions so occasional embedded uptick toward 2"/hr rates. The higher residency of a few hours to exhaust the unstable air, should allow for localized totals of 2-3"+ perhaps an isolated 4" total. There is a fairly sharp gradient of soil saturation conditions across central KS being wetter further south. Still, FFG values of 1.5"/hr and less than 3"/3hrs seem approachable suggesting a few scattered incidents of flash flooding are considered possible through the remainder of the overnight period. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!8CmRk1etGdEO6-eWZwsb5ll8cjyE_b2n0s0slx-Z4dZQhZWEBj494Vlkqh0ni14PBPwx= SYrLk1g74k_Uxy9CsqWAOWg$ for graphic product... ATTN...WFO...DDC...GID...GLD...ICT...TOP... ATTN...RFC...KRF...TUA...NWC... LAT...LON 39499740 39369669 38579653 37849834 37820024=20 38210134 38620178 39130159 39350117 39340033=20 39239918 39299818=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 3.28-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .