Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Wed Jul 19 2023 17:46:47 AWUS01 KWNH 191746 FFGMPD TNZ000-KYZ000-ILZ000-MOZ000-192200- Mesoscale Precipitation Discussion 0763 NWS Weather Prediction Center College Park MD 146 PM EDT Wed Jul 19 2023 Areas affected...Southeast MO, southern IL, western KY, western TN Concerning...Heavy rainfall...Flash flooding possible Valid 191744Z - 192200Z Summary...Periods of moderate rain will continue through the afternoon atop extremely saturated soils. Additional rainfall of 1-2" with locally higher amounts is possible. This may lead to renewed or exacerbated flash flooding. Discussion...The GOES-E visible imagery this aftn depicts expansive cloud cover in the vicinity of this mornings persistent MCS from central MO through eastern KY and eastern TN. Within this cloud cover, some bands of deeper Cu are developing along outflows, differential heating boundaries, and through isentropic upglide along a warm front analyzed by WPC to the southwest. While the overall intensity of convection has waned due to overturning/exhaustion of the instability, these convergent boundaries are driving renewed lightning, especially upstream into Missouri. The 850mb inflow according to the SPC RAP remains from the WSW at 20-30 kts, resupplying more favorable thermodynamics characterized by PWs of 1.8-2.0 inches and MLCAPE of 2000-3000 J/kg northward. The high-res guidance differs in evolution during the next few hours, producing somewhat lowered confidence in the evolution through this evening. However, thunderstorms building across Missouri along linear convergent boundaries will likely train to the E/SE on mean 0-6km winds of 20-25 kts. These storms will move southeast parallel to the front, with additional development occurring upstream to suggest at least short term training of rain rates that may reach 1"/hr. While current instability across KY/TN is generally exhausted noted by MLCAPE of just 250-500 J/kg, the resupply of the thermodynamics from the SW may allow this to re-destabilize quickly as the cloud cover erodes. This will allow storms to better maintain intensity as they train to the southeast this aftn and into the evening, resulting in additional rainfall of 1-2" with locally higher amounts. This rainfall in itself does not generally appear sufficient for flash flooding. However, 12-hr rainfall from this morning has been widespread of 3-7" with locally more than 10" in some areas. This has resulted in fully saturated soils noted by the HRRR soil saturation percent, anomalous USGS streamflows, FFG as low as 0.25-0.5"/1hr, and ongoing flash flooding. Any additional moderate rainfall on top of these soils could result in renewed or exacerbated flash flooding. Weiss ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4kD5P1ZXd4-lYHnSMZNsRG_2kDUDT48LkcTtB8flL79TtkXkVKB2hFqXJaxL1GhWWo36= f0P_46cxnoePrEL3hdKowEY$ for graphic product... ATTN...WFO...HUN...LMK...LSX...MEG...MRX...OHX...PAH...SGF... ATTN...RFC...LMRFC...MBRFC...NCRFC...OHRFC...NWC... LAT...LON 38369155 38369042 38178958 37588805 36458629=20 35788567 35308556 35088644 35108746 35388834=20 35978927 36739034 37269164 37419226 37589249=20 37919239=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) .