Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Mar 03 2023 10:26:10 AWUS01 KWNH 031026 FFGMPD TNZ000-KYZ000-INZ000-ILZ000-MSZ000-MOZ000-ARZ000-031625- Mesoscale Precipitation Discussion 0086 NWS Weather Prediction Center College Park MD 525 AM EST Fri Mar 03 2023 Areas affected...Portions of the Lower MS Valley through the Lower OH Valley Concerning...Heavy rainfall...Flash flooding likely Valid 031025Z - 031625Z SUMMARY...Widespread heavy rainfall and flash flooding will continue to be a major concern this morning across portions of the Lower MS Valley and with increasing coverage of this threat across the Lower OH Valley. DISCUSSION...The powerful upper-level trough and associated closed low ejecting across the Lower MS Valley is beginning to take on a negative tilt and will be lifting northeast this morning toward the lower OH Valley while driving a consolidating and rapidly deepening area of surface low. Ahead of this low center will continue to be a strong low-level jet of 50 to 60 kts that will be interacting with and overrunning a warm front lifting from the Mid-South northward into the OH Valley. Very strong forcing remains in place early this morning along this front given the enhanced low-level jet energy and proximity of strongly divergent flow aloft associated with a powerful upper-jet couplet. The warm sector airmass pooling northward is characterized by MUCAPE values of 500 to 1000 J/kg, with the better instability focused down over the Mid-South, but is quite moist with PWs of 1.3 to 1.7 inches as seen with the latest GPS data. The expectation is that the ongoing axis of very heavy rainfall advancing through eastern AR, southeast MO, western KY and far northwest TN will continue to lift northeastward this morning with sustainable convection that will be capable of training over the same area. The rainfall rates have tended to come down somewhat over the last couple of hours given a downward trend in instability, but will still be capable of reaching 1 to 1.5 inches/hour given the very strong forcing along the front. Gradually the heaviest rainfall axis should shift up into areas of southern IL, southern IN and more areas of western KY where additional rainfall amounts of 2 to 4 inches of rain are likely by late morning. This is consistent with the 00Z/06Z HREF guidance. Given some of the rains that have already occurred, and the saturating soil conditions, this should correlate to a rather widespread threat of flash flooding in time. Additional flash flooding will also be expected at least locally across parts of central and eastern AR this morning as the core of the upper low pivots across the region brings additional rounds of heavy showers and thunderstorms which will aggravate the ongoing runoff and flooding problems here. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!6fpPYQFHDMLjb8jMYVL7-6IEX547nKq88RxbrqaFGVkf4SFOQBeg_yzhRL-gtME2vGkD= TD_ywCe-xe_mTKozWcxyhZ0$ for graphic product... ATTN...WFO...ILN...ILX...IND...JAN...LMK...LSX...LZK...MEG... OHX...PAH...SGF... ATTN...RFC...ABRFC...LMRFC...NCRFC...OHRFC...NWC... LAT...LON 39638695 39408604 39028543 38138517 37048651=20 35798822 34338979 33599119 33599249 34399325=20 35669282 36639206 37649112 38179038 38848943=20 39418820=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) .