Mesoscale Precipitation Discussion 0459...Corrected
NWS Weather Prediction Center College Park MD
237 PM EDT Mon Jun 16 2025

Corrected for FF Likely

Areas affected...Western & Central KY...Southern IND...Southern
IL...Southeast MO...Northeast AR...Adj. TN

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

Valid 161800Z - 162330Z

SUMMARY...Slow moving, efficient thunderstorms capable of 2-3" in
1-2 hours pose localized flash flooding conditions, especially
upstream over saturated ground conditions/low FFG.

DISCUSSION...GOES-E WV suite shows a broad anticyclonic arch of
high cirrus indicative of broad mid to upper level confluent flow
to speed max over central Ohio Valley (generally 50kts). This
results in a broad entrance region with favorable upper-level
divergence to support/maintain an elongated shear axis from a
stalled/shortwave feature across the eastern Ozark Plateau to a
convectively reinforced short-wave crossing southern IL into
southwest IND at this time.  The combination of broad scale ascent
has provided ample broken to dense mid to upper-level cloud
features reinforcing surface front through differential heating
across northeast AR into Western KY.  Visible imagery also helps
to denote the surface to 850mb low across N AR with front
generally along the southern portion of the cloud line across SE
MO, S IL into SW IND.  Low level moisture remains above normal and
into the low to mid 70s wrt dewpoint and CIRA LPW in the surface
to 850mb within the Mississippi and Lower Ohio Valley nearing 1"
in places.  As such, a plume of 2"+ TPW exists across the area
expanding eastward into western KY.  Heating into the mid to upper
80s will steadily increase instability over 1500 J/kg MLCAPE with
SBCAPEs already over 3000 J/kg.  As such, recent convective
initiation has been quick and vigorous across S IL/W KY and will
likely become quickly efficient in rainfall production given the
flux through the core of the moisture plume.  Rates of 2"/hr are
likey though 15z HRRR hints that 15-minute totals may reach 1.5"
given the overall efficiency/deep warm cloud processes.

Deep layer flow should allow for cells to be fairly progressive
especially east of the MS River valley and organized structures
are likely to be clustered along and south of the frontal zone. 
Random upstream redevelopment has potential for repeating tracks,
so spots of 2-3" totals are probable through the late
afternoon/early evening.  Cells near the surface to 850mb low are
likely to be slower in eastward cell motions being a tad further
west of the jet entrance with perhaps a cell getting lodged on
some of the hills of the eastern Plateau given some favorable
upslope.  Additionally, FFG values are reduced upstream due to
heavy rainfall last evening with 1hr values less than
1.5"...though downstream in W KY are still between 1.5-2" with 3hr
values in the 2-2.5" range.   While the incidents of flash
flooding are likely to be scattered in nature throughout the MPD
area, the probability of FFG exceedance is likely and most
probable upstream with lower FFG and slower cell motions (though
lesser deep moisture/instability).

Gallina

ATTN...WFO...ILX...IND...LMK...LSX...LZK...MEG...OHX...PAH...
SGF...

ATTN...RFC...MSR...ORN...TIR...TUA...NWC...

LAT...LON   39008653 38658541 38158488 37568483 36788544
            36538799 35749027 35339189 35679272 36239272
            37009205 37639098 38588915 38908806