147
AWUS01 KWNH 241508
FFGMPD
TNZ000-KYZ000-ALZ000-ILZ000-MSZ000-MOZ000-241900-

Mesoscale Precipitation Discussion 0315
NWS Weather Prediction Center College Park MD
1107 AM EDT Fri May 24 2024

Areas affected...Portions of the Tennessee Valley

Concerning...Heavy rainfall...Flash flooding likely

Valid 241506Z - 241900Z

SUMMARY...Influx of moisture on south-southwesterly flow is
allowing storms across the Lower Ohio and Tennessee Valleys to
backbuild. The storms have a history of over 2 inch per hour
rainfall rates with the most persistent backbuilding. Ongoing and
new flash flooding will continue into the afternoon.

DISCUSSION...A line of convection that formed on the leading edge
of a now dissipated MCS over Arkansas has been backbuilding this
morning as 30-40 kt south-southwesterly flow at 850 mb injects
moisture with PWATs over 1.5 inches into the storm complex. While
individual cells have been moving, backbuilding and training of
newly formed convection over the same areas has resulted in flash
flooding over western Tennessee and northeastern Mississippi.
Isolated pockets of 4 inches storm total rainfall have been
analyzed by the Memphis radar along the line of storms.

Backbuilding may continue into the early afternoon hours as the
flow remains steady and additional moisture advects into the area.
The influx of moisture into the back edge of the storms supports
continued backbuilding/training. This is suggested by the latest
HRRR and CONEST runs, though neither have been performing well
with the evolution of the storms so far. With differential daytime
heating, the complex should weaken with time albeit with
significant disagreement on how long that will take.

Wegman

...Please see www.wpc.ncep.noaa.gov for graphic product...

ATTN...WFO...BMX...HUN...LSX...MEG...OHX...PAH...

ATTN...RFC...LMRFC...NCRFC...OHRFC...SERFC...NWC...

LAT...LON   37968846 37518788 36598807 36118779 35548721
            34948705 33958701 33868778 34148859 34648881
            35278910 35858940 36488975 36969000 37399022
            37969020 37948919