Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Jun 27 2025 18:04:10 AWUS01 KWNH 271803 FFGMPD ILZ000-MOZ000-ARZ000-OKZ000-KSZ000-280000- Mesoscale Precipitation Discussion 0529 NWS Weather Prediction Center College Park MD 203 PM EDT Fri Jun 27 2025 Areas affected...The Ozarks Concerning...Heavy rainfall...Flash flooding possible Valid 271801Z - 280000Z Summary...Showers and thunderstorms expanding across Missouri will intensify through the afternoon. Rainfall rates may peak above 2"/hr at times within these slow moving storms, possibly leading to instances of flash flooding. Discussion...The regional radar mosaic this afternoon shows convection rapidly expanding along what appears to be an old outflow boundary downstream of a cold front draped NE to SW across southern Missouri. Ascent along this boundary is occurring due to convergence, but is being aided by synoptic lift through the RRQ of a jet streak arcing to the northeast and a shortwave moving eastward across KS. This lift is impinging into robust thermodynamics characterized by a ribbon of PWs of over 2 inches, near record for the date, combined with SBCAPE over 3000 J/kg fueled by steep lapse rates within the 850-600mb layer noted on the morning regional UA soundings. In this environment, thunderstorms have rapidly blossomed, with additional updrafts quickly expanding as noted on the GOES-E day-cloud phase RGB, suggesting the rain rates that are currently estimated to be above 2"/hr from KSGF will only intensify the next few hours. Storms that have developed already are not moving quickly. The 0-6km mean wind is only around 10 kts to the NE, but more concerning are Corfidi vectors aligned anti-parallel to the mean wind and collapsed to just 5 kts or less. This is dictating the slow storm motion already noted, and will support backbuilding of echoes into the greater instability to the SW as 850mb inflow remains from the W/SW at 10-20 kts. This will result in some areas receiving multiple rounds, or experiencing a long duration, of heavy rainfall. With the HREF (REFS) probabilities for 2"/hr reaching 20-30% (30-50%), this suggests brief rain rates of 3"/hr are also likely, which is additionally supported by HRRR 15-min rainfall peaking around 0.75" through this evening. Where these rates train or stall through backbuilding, 2-3" of rainfall is expected, with locally as much as 5" possible. The slow movement of these intense rates could quickly overwhelm soils leading to runoff, especially in urban areas. However, NASA SPoRT 0-40cm soil moisture also reflects recent wetness across the area, as soil moisture near the AR/MO border and into far eastern OK are in the 80th-90th percentile. Despite FFG that is quite high across the region (2.5-4"/3hrs), there is at least a 20-30% chance of exceedance due to the slow movement of these intense rain rates, further suggesting the increasing flash flood risk through this evening. Weiss ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4Vh1-2_CCShQunh7CZpg9lXZ8zlwnD-xm7TXgSoFXQ0Snjn1HT9n5l4qJTVQO1-kDfOw= mpb4JEReYSI6G0ZNSE7B3oo$ for graphic product... ATTN...WFO...ICT...LSX...LZK...MEG...PAH...SGF...TSA... ATTN...RFC...KRF...MSR...ORN...TUA...NWC... LAT...LON 38689096 38559036 38109002 37728990 37079024=20 36249096 35739195 35489287 35449416 35609524=20 35819583 36269632 36779633 37219599 37589502=20 38039353=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) .