Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jun 29 2025 03:40:34 AWUS01 KWNH 290340 FFGMPD MNZ000-SDZ000-290800- Mesoscale Precipitation Discussion 0546 NWS Weather Prediction Center College Park MD 1139 PM EDT Sat Jun 28 2025 Areas affected...eastern South Dakota, southern/central Minnesota Concerning...Heavy rainfall...Flash flooding likely Valid 290339Z - 290800Z Summary...Intense thunderstorms have taken on a favorable orientation for training, with spots of 2-3 inch/hr rates persisting for a couple hours just southeast of Watertown, SD.=20 Heavy to extreme rain rates could pose locally significant flash flood potential through at least 07Z. Discussion...Recent mesoscale trends indicate a linear MCS extending from just southwest of Watertown, SD to near Willmar, MN. The linear MCS was backbuilding along the northern extent of a 25-30 kt southwesterly 850mb jet centered near Sioux Falls, SD.=20 Substantial backbuilding and training was occurring with this activity, and MRMS estimates of 5-7 inches of rainfall exist just southeast of Watertown with this activity. Steep lapse rates and abundant moisture will continue to fuel backbuilding activity in the short term, and heavy to extreme rain rates will likely accompany this activity. While the evolution of this band through the night is a bit uncertain, observations suggest that training convection will continue for at least the next 3-4 hours at least with synoptic-scale atmospheric features not expected to evolve much in that timeframe. The ongoing band will likely continue to backbuild while either remaining stationary or moving slowly southeastward in response to local cold pool development and other mesoscale processes. The band may also build eastward in to more of southern Minnesota. The degree of training in any one spot will be a primary factor modulating rainfall totals through 07Z.=20 Additional 3-7 inch rainfall totals cannot be ruled out. Locally significant flash flooding may occur with this activity. Cook ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6grJJVDF1DuzAFEm1feLPyY8scMlD8SFbN4V5WFkQPCpdf-UKEXQNCH7uZ7cQBsIhEZG= RS1jbxJFfx4k3HhmVziLCS8$ for graphic product... ATTN...WFO...ABR...ARX...FSD...MPX... ATTN...RFC...KRF...MSR...NWC... LAT...LON 45269446 45109341 44569281 43969300 43639568=20 43859793 44659807 45099677=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) .