Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Dec 10 2024 15:31:20 AWUS01 KWNH 101531 FFGMPD GAZ000-ALZ000-MSZ000-LAZ000-102130- Mesoscale Precipitation Discussion 1172 NWS Weather Prediction Center College Park MD 1030 AM EST Tue Dec 10 2024 Areas affected...Parts of the Deep South and Southeast Concerning...Heavy rainfall...Flash flooding possible Valid 101530Z - 102130Z SUMMARY... Increasing coverage of showers and thunderstorms through this afternoon will be capable of containing hourly rates up to 2"/hr and 6-hourly totals over 3", while likely training over similar areas. This will lead to scattered flash flooding potential, mainly for urban and low-lying locations DISCUSSION... Current satellite, radar, and surface observations display a developing southwest-northeast oriented axis of showers and thunderstorms extending from eastern LA to central AL. These showers and thunderstorms are forming in advance of a deep upper trough (-1.0 to -1.5 standardized anomaly per 00z ECENS) stretching from the Upper Midwest to the Southern Rockies. This trough is aiding in strong uniform southwesterly flow advecting anomalous moisture throughout the column with a source region of the eastern Pacific, visible via GOES-West ADV LPW. Actual PW values of 1.5"-1.7" currently spans from eastern LA to central GA, but these values are forecast to expand throughout the day into the Southeast in response to strengthening mid and upper level flow as the the aforementioned trough takes on more of a neutral tilt over the central U.S. Radar and GOES-East visible satellite this morning depicts and a few subtle areas of convergence extending to the northeast of the approaching cold front. One area impacting Birmingham, AL and a separate more noticeable axis to the south over Montgomery, AL and the I-65 to I-85 corridor. These areas of convergence are most likely to display training storms within the deep uniform southwesterly flow, with greater instability (500-1000 J/kg) advecting into the southern line. Overall, CAMs and 06z HREF guidance display that hourly rates are not expected to exceed 2" outside of very localized locations, but that 6-hourly totals could exceed 3" and this would top the 6-hr FFG. So areas experiencing training thunderstorms will be most at risk for excessive rainfall as opposed to impacts from individual cells. Overall, if these amounts are realized it is expected that scattered low-lying and urbanized locations could experience rapid water runoff and flash flooding impacts, particularly after 18z along the I-85 and I-65 corridors of AL. Snell ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9I0Lt1rnPx9qCAo9zkE6kisJU6T2p8DxE5PKBP-g4294KOZjc8QtecrsXJ5kPF0yaCJM= NEGcZ5UU0Ls0nhxvVmVupF0$ for graphic product... ATTN...WFO...BMX...FFC...JAN...LIX...MOB... ATTN...RFC...LMRFC...SERFC...NWC... LAT...LON 34148494 33898413 33208394 32328501 31338706=20 30698864 30408964 30619019 31059021 31738971=20 32528879 33258766 33848634=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) .