Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jul 02 2024 18:37:27 AWUS01 KWNH 021837 FFGMPD WIZ000-ILZ000-MOZ000-IAZ000-NEZ000-030000- Mesoscale Precipitation Discussion 0541 NWS Weather Prediction Center College Park MD 236 PM EDT Tue Jul 02 2024 Areas affected...Iowa Concerning...Heavy rainfall...Flash flooding likely Valid 021836Z - 030000Z SUMMARY...Training convection expected to develop along a warm front ahead of a developing low will cause storms to develop with rates up to 3 inches per hour. Given recent heavy rainfall, flash flooding is likely. DISCUSSION...Broad, nearly unidirectional WSW flow across Iowa has developed ahead of a developing low and right entrance region of a southwesterly upper level jet streak. Showers and thunderstorms continue to develop along this warm frontal boundary, which the surface low will track along through the afternoon. The air mass south of the warm front is anomalously moist, with PWATs over 2 inches across southwest Iowa from SPC Mesoanalysis. MUCAPE values are over 4,000 J/kg in the northwest corner of Missouri, so the atmosphere is well-primed for the development of strong convection through the afternoon. Much of Iowa has seen 200 to 300% of their normal rainfall over the past 2 weeks, so soils are nearly saturated and many rivers in the area are above flood stage already. The storms are expected to be fast moving in the unidirectional flow, which will certainly help to hold down rainfall totals in any one area, however due to the high likelihood of training storms as well as rainfall rates up to 3 inches per hour, additional flash flooding from the storms is likely where the strongest training storms are the most persistent. This is most likely to occur over central Iowa. WoFS guidance highlights the corridor from the southwest corner of Iowa to the southwest corner of Wisconsin through the east side of Des Moines as the most likely corridor for 2 inch per hour rates with some 3 inch per hour rates possible through Des Moines. By the time the storms reach eastern Iowa towards 00Z, much of the CAMs guidance is in agreement that the storms will have bowed out into an intense squall line, which will greatly limit the potential for flash flooding. However, due to ongoing major river flooding along the Mississippi River, the additional rainfall from the line could cause localized nuisance flash flooding due to poor drainage from adjacent land areas. Additional training convection may form this evening, so updates along and south of this MPD area are likely. Wegman ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4VJuLLqBP_Q4M39ml2Pn1aOSTVJ8AitP8Rc45vC4obxzU6GwI_nS7VMc1QOi8-gF6-TF= -iTLkE8LV3NMITAiRflMVEQ$ for graphic product... ATTN...WFO...ARX...DMX...DVN...EAX...MKX...OAX... ATTN...RFC...MBRFC...NCRFC...NWC... LAT...LON 43249100 43119042 42849025 41658985 41139117=20 40219450 40229579 41449574 42159539 42479482=20 43059333=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) .