Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Jul 29 2024 07:59:47 AWUS01 KWNH 290759 FFGMPD ILZ000-MOZ000-IAZ000-291400- Mesoscale Precipitation Discussion 0753 NWS Weather Prediction Center College Park MD 358 AM EDT Mon Jul 29 2024 Areas affected...South-central & Southeast IA...Western & Central IL...Northeast MO... Concerning...Heavy rainfall...Flash flooding possible Valid 290800Z - 291400Z SUMMARY...Mature MCS with embedded training elements may continue to pose a risk of 2-4" in the training axis and possible flash flooding through the early morning. DISCUSSION...GOES-E 10.3um EIR and regional RADAR mosaic show a maturing/consolidating training line from south-central IA into southeast IA. Currently, peak orthogonal ascent over the NW to SE outflow boundary is providing solid deep moisture convergence. RAP analysis appears to have a good assimilation/analysis of a stable air pocket over northern and northeastern IL building into an increasing gradient toward the west, though MUCIN continues to be very strong across NW MO with strong clearing/subsidence warming noted in EIR and WV suite respectively in that area. As such, convection is likely to remain oriented favorably with limited southwest propagation, favoring downstream propagation as the LLJ continues to veer more parallel to the convective line. Apex of 500-1000mb thickness ridge appears to be along just southwest of the IA/MO/IL intersection, so further southward propagation and increased orthogonality from westerly LLJ may help expansion of the line along through the Mississippi River Valley, but current trends suggest best probabilities remain from Wapello to Lee county in IA into McDonough county, IL. Moisture of 1.75-2" convergent on 30-35kts should support increasing rainfall rates up to 2"/hr. Spots of 2-4" are probable; through early morning. The far northeastern corner of MO, may see a chance for the training axis as well. As the mature MCS moves east into northern and central IL, increased divergent flow in the mid to upper levels will broaden cell motions. Increasing reverse inflow jet aloft, may also support forward acceleration of the leading bow echo and generally reduce rainfall efficiency. Only near the cyclonic bookend of the circulation likely to track along/north of I-80 may increase duration and potential for a spot or two of 2-3", combined with generally wetter ground conditions and lower FFG, the potential for a widely scattered incident north of the upstream training axis of thunderstorms still may be possible and so the area of concern was broadened to account for this potential across north-central IL. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4gDDzathQG-xiAo3otc2YNwlmNRsnvPWlXQJZmr4YrHy1iFkHU634xcKOTfqqqTNd51J= oof0MK4hR8BpKE0BEWkDCYs$ for graphic product... ATTN...WFO...DMX...DVN...EAX...ILX...LOT...LSX... ATTN...RFC...MBRFC...NCRFC...OHRFC...NWC... LAT...LON 41828919 41168838 40088834 39348864 38788955=20 38719076 39669207 40289280 41179374 41569347=20 41439201=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) .