Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Apr 16 2024 06:31:49 AWUS01 KWNH 160631 FFGMPD MNZ000-IAZ000-NEZ000-SDZ000-161200- Mesoscale Precipitation Discussion 0157 NWS Weather Prediction Center College Park MD 231 AM EDT Tue Apr 16 2024 Areas affected...Southeast SDak...Northeast NEB...Northwest Iowa... Concerning...Heavy rainfall...Flash flooding possible Valid 160630Z - 161200Z SUMMARY...Slow moving, locally intense thunderstorms may produce some widely scattered spots of 2"+ rainfall precursory to stronger wave and additional thunderstorms approaching toward daybreak across the Mid-Missouri Valley. Some low-end incidents of flash flooding may be possible; but will at least set the stage for increasing risk later this morning. DISCUSSION...GOES-E 10.3um EIR and WV suite imagery depict a broadening/cooling convective complex within the highly diffluent western branch of the upper level jet across the Mid-Missouri River Valley providing excellent outflow aloft to maintain convective development. In the lower levels, well defined surface stationary front across the SDak/NEB line angles south through the river valley into northwest MO, delineating moist air with low to mid 60s Tds in the warm sector compared to 30s/40s north of it.=20 Stronger shortwave of main closed low has shifted into the central High Plains advancing toward the area and the low level jet has responded with solid confluence in the sfc to boundary layer region enhancing convergence at the frontal zone across NE NEB; flux of 45-50kts and the enhanced moisture along the boundary continues to provide solid flux through overall moisture values/depth is limited to 1.25-1.3", but will steadily increase toward 1.5" by late morning. Highly unstable mid-levels (MUCAPES of 2000-2500 J/kg) are resulting in the stronger updrafts and given the flux into the low levels has been initially resulting in hail and cold pool generation, steepening the front. Deep layer flow supports north to northwest cell motions; however, it is the anchoring of the frontal zone and initiation spots that will aid back-building regenerative updrafts capable of increasingly efficient rainfall production. Rates of 1.5"/hr may become closer to 2" with time and strengthening approaching mid-level forcing toward 12z. Still the overall duration may result in localized spots of 2-3" and may induce an instance of flash flooding in the vicinity (just north) of the stationary front until that time, and therefore is considered possible for the Mid-Missouri Valley through 12z. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6jgNRNMqBxG33JB049xZqzLJdh8f7doitT5-wUFPpKWcgzBTNL3fqFp8356WuPSZaESa= 6rYP8eOnPtH_0AwG35_c3Hg$ for graphic product... ATTN...WFO...DMX...FSD...OAX... ATTN...RFC...MBRFC...NWC... LAT...LON 44079726 43629627 42919546 42379515 41389503=20 40989595 42029717 42889827 43319861 43909835=20 =20=20=20=20=20=20=20=20=20=20=20=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) .