Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Jun 05 2025 05:00:20 AWUS01 KWNH 050500 FFGMPD KYZ000-INZ000-ILZ000-MOZ000-051030- Mesoscale Precipitation Discussion 0366 NWS Weather Prediction Center College Park MD 1259 AM EDT Thu Jun 05 2025 Areas affected...Southeast MO...Southern IL..Southwest to Central IND...Adj KY... Concerning...Heavy rainfall...Flash flooding possible Valid 050500Z - 051030Z SUMMARY...Increasing convective efficiency with clusters.=20 Favorable orientation may allow for multiple repeating rounds resulting in widely scattered incidents of 2.5-3.5" totals and possible localized flash flooding. DISCUSSION...GOES-E WV along with RADAR mosaic denotes well defined shortwave/MCV crossing SE IL into west-central IND, with excellent anticyclonic outflow channeling to maintain MCV strength and therefore low level inflow. WV suite and RAP analysis also shows another subtle upstream shortwave, weak feature that can be seen in 850mb vorticity analysis near the MO Bootheel in Northern AR, moving even slower northeast. 850mb flow analysis shows return moisture channel across the TN Valley becoming convergence/confluent through the Tri-Rivers area of W KY intersecting with the frontal zone and outflow boundaries from initial convection. VWP shows 25-35kts of 925-850mb flow within the q-axis with 1.75-2" total PWATs stretched out across central IND back to the 850mb inflection in SE MO. This advection/q-axis has some remaining uncapped/weakly capped 1000-1500 J/kg of MLCAPE that can be utilized at those random intersections of deep layer moisture convergence near the boundaries. Additionally, 300-500mb flow is increasingly diffluent along th southeast side of the clustering providing solid ascent/outflow to maintain favorable ascent through the overnight period.=20 As such, recent 10.3um EIR and RADAR mosaic shows increasing convective activity mainly along the upwind flanking line of the stronger outflow boundary from the original MCV across central IND back into S IL, as well as the best convergence in SE MO into S IL. Overall, moisture flux and vigor suggests increasing rainfall efficiency toward 1.5-2"/hr likely to evolve over the next few hours, particularly in the best unstable environment from MO to SW IND. Each cluster has solid potential for 1-2.5" totals...but deep layer steering between waves is flattening to support clusters repeating through the overnight period and may result in localized pockets up to 3.5" though most streaks/clusters of enhanced totals will be in the 2-3" range. Hydrologically, grounds are fairly average in soil moisture and therefor should up-take modest rainfall well with good infiltration. However, the rates near 2" are in the vicinity of the hourly FFG values, as well as the 3hr values ranging from 2-3". This provides enough confidence for a few scattered incidents of possible flash flooding over the next 6hrs and matches up well with 00z HREF probability of 3"/6hr probability ranging up to 45% across potions of the highlighted area of concern.=20 Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4MK0OthzKFSTxx5XSaA6doI5tt8VJCuq_hiGxGDZ9KcKMPv6F54RrYSxZNRHURIjxHFU= TpJUNkijFIhNP0gOLOVwzfE$ for graphic product... ATTN...WFO...ILX...IND...LMK...LSX...PAH... ATTN...RFC...MSR...ORN...TIR...NWC... LAT...LON 39928640 39478601 38658610 38038669 37408752=20 37188787 36988828 36708882 36699006 36589049=20 36739102 37089099 37549037 38268901 38568846=20 39158772 39858698=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) .