Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon May 08 2023 00:22:35 AWUS01 KWNH 080022 FFGMPD INZ000-ILZ000-MOZ000-IAZ000-080620- Mesoscale Precipitation Discussion 0235 NWS Weather Prediction Center College Park MD 821 PM EDT Sun May 07 2023 Areas affected...Southeast IA...Northern/Central IL...Northern/Central IN Concerning...Heavy rainfall...Flash flooding likely Valid 080020Z - 080620Z SUMMARY...Heavy showers and thunderstorms will continue to develop and grow upscale this evening across large sections of the Midwest, including southeast IA, much of northern and central IL, and northern and central IN. Given concerns for cell-training and multiple rounds of convection, scattered areas of flash flooding are likely. DISCUSSION...The latest radar and satellite imagery shows notably concentrated areas of convection impacting portions of southeast IA and into large areas of western and central IL, and parts of northern IN as broad warm air advection continues into this area ahead of low pressure currently situated over southeast NE. The activity is also being strongly facilitated by the proximity of a front draped from southern IA and eastward across northern IL and into north-central IN. A moderate to strongly unstable airmass with MLCAPE values of 1500 to 3000 J/kg continues to interact with this frontal zone, and with approaching upstream shortwave energy expected to arrive later this evening from the central Plains, there should be a sustainable focus for developing and organizing clusters of convection that will have upscale MCS evolution heading into the overnight hours. Nearby proximity of an outflow boundary over areas of western IL to the south of the main synoptic front is also another focus for convective redevelopment which is addressed in MPD #234. The latest HRRR guidance is well underdone with its QPF potential over the next few hours across areas of especially northern/central IL and parts of northern IN where convection is quite well-organized and being poorly handled by not only the HRRR, but also the consensus of 18Z HREF guidance. Very heavy rainfall rates of 2 inches/hour are expected this evening with the stronger convective cells, and since the cells are rather slow-moving and tending to locally train/repeat over the same area, there will be concerns for excessive totals that may reach as high as 3 to 5 inches by midnight. The additional focus for renewed convective development upstream with the approaching energy from the central Plains will also be another factor over the next several hours that support locally enhanced rainfall totals. Given the ongoing activity and additional focus for later this evening, scattered areas of flash flooding appear likely. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4WK38qmqlAwsfTGaAPbLMO2GzbEKooG6MYM3ZmgX302NSCDFeoxHqYzk2YhPX_ETSup9= uN2fvDkNDsIVMKDjiMiDyAc$ for graphic product... ATTN...WFO...DVN...ILX...IND...IWX...LOT...LSX... ATTN...RFC...NCRFC...OHRFC...NWC... LAT...LON 41838904 41688772 41378622 40868533 40478517=20 40258545 39968604 39748761 39778917 39319008=20 39599107 40659182 41389140 41709071=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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .