Mesoscale Precipitation Discussion 0097
NWS Weather Prediction Center College Park MD
1029 PM EDT Sun Mar 30 2025

Areas affected...Central & Eastern KY...Western & Middle
TN...Northern MS...Northwest AL...

Concerning...Heavy rainfall...Flash flooding possible

Valid 310230Z - 310800Z

SUMMARY...QLCS starting to have bowing segments that will result
in a few streaks of enhanced moisture convergence and increased
heavy rainfall duration resulting in streaks of 2-4" totals and
possible localized flash flooding.

DISCUSSION...Regional RADAR mosaic denotes solid and broadening
squall line across central KY angling back across W TN into far
northeast AR. Maturing bowing segments are starting to arch out
with meso-low/inflections noted in the north near Henry county, N
KY and Christian/Tocd counties in S KY and generally flattening
near the tail of sufficient deeper layer convergence/mid-level
forcing from the exiting shortwave across central IND.  Modestly
broad wedge axis of unstable air remains in place along/ahead of
the line with 500 along the Ohio River back to 2000 J/kg MLCAPE
across N MS/W TN attm.  Moisture is not particularly deep, through
the layer, but the strength of flux on 40kts of confluent boundary
layer to 850mb flow has resulted in 1.25-1.5" total PWat values. 
Given the strength of the convergence both in speed and direction
through depth intersecting with outflow boundaries will support
solid rates of 1.5-2"/hr with bulk falling in initial 15 minutes
(HRRR and WoFS sub-hourly rates suggesting 1.25/15 minutes with
.35-.5"/5 minutes rates, respectively).

While the broad post-squall shield precipitation is increasing,
especially further north toward better divergence aloft, overall
totals are likely to be around that 1.5-2" range, which remains
slightly below even 1hr FFG values across KY (which are higher
south).  However, given these bowing segments and embedded
inflections are helping to back sfc to boundary layer flow with
oriented outflow boundaries, orthogonal to the flow, isentropic
ascent will increase downstream and increase duration in proximity
of these inflections, allowing for localized 2-3" streaks to form
along the QLCS, as well as the tail end cells where forward
steering flow is weaker across W TN/N MS.  WoFS 90th percentile
have some suggestions of totals nearing 4" across N Middle TN,
which seems plausible.  Still 3hr totals of 3" would pose possible
flash flooding even into the southern portion of the MPD area of
concern (though 3+ to 4" would make it more probable).  As such,
most locations will not see flooding concerns, but there is enough
of a signal and trends to suggest a few streaks will result in
flash flooding through early morning. 

Gallina

ATTN...WFO...HUN...JKL...LMK...MEG...MRX...OHX...PAH...

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

LAT...LON   38268398 37908305 37108282 36388380 35388543
            34658724 34338937 34609036 35349034 36128917
            36708833 37838627 38238537