AWUS01 KWNH 011145
FFGMPD
TNZ000-KYZ000-INZ000-ILZ000-MOZ000-011700-

Mesoscale Precipitation Discussion 0293
NWS Weather Prediction Center College Park MD
744 AM EDT Mon Jun 01 2026

Areas affected...Southern IL...Western KY...Western & Middle TN...

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

Valid 011145Z - 011700Z

SUMMARY...Repeat/Training thunderstorms expanding downstream of
matured MCS.  Hourly rates up to 2" and totals of 2-3" 
approaching FFG values, suggesting localized flash flooding is
possible this morning.

DISCUSSION...GOES-E EIR, early visible imagery and regional RADAR
mosaic denote rapid cooling, convective initiation across western
KYy expanding into northwest TN downstream of the mature MS across
the central MS River Valley. GOES-E WV shows compact driving
shortwave behind the MCS over NW MO with complex moving into
broadening diffluent flow aloft.  This remains supportive of broad
larger scale ascent, though cold pool generation is supporting
quicker southeast propagation.   

VWP and RAP analysis still show veering WAA low level flow of
20-25kts across the MS Valley with slightly increasing downstream
convergence to support the convective initiation.  MUCAPE values
of 2500-3000 J/kg remain slightly uncapped that this convergence
was sufficient and the instability corridor extends further
downstream into Western and Middle TN to suggest potential for
further expansion/maintenance of the new cells and approaching MCS
line.   In addition to the confluence, the area downstream remains
a pool of enhanced low to mid-level moisture supporting 1.75" of
Total PWats, with CIRA LPW denoting even a narrow 700-500 mb axis
through W KY into Middle TN to help reduce some mid-cloud
evaporation.   As such, common rates of 1.5-1.75" with occasional
2"/hr values with strongest updrafts will align favorably to
500-1000mb thickness pattern to support training/repeating
environment.   The limiting factor is likely to be the increasing
forward propagation due to the cool pool/meso-high driving the MCS
convective line (as the MCS weakens...noting warming already
occurring in the main canopy).

Hydrologically, southern IL remains very dry, with 0-40cm soil
moisture at or below 25%, but soil conditions steadily moisten
toward the southeast into Middle TN reaching the 40s and 50+%
which is average to slightly above average per NASA SPoRT.  As
such, FFG values of 1.5-2"/hr and 2-2.5"/3hrs exist across W KY
into Western and Middle TN; so there remains a low-end potential
for exceedance with the best repeating and totals of 2-3" through
mid-morning, suggesting a localized incident of flash flooding
remains possible.

Gallina

ATTN...WFO...MEG...OHX...PAH...

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

LAT...LON   38178881 37928803 36648708 36028667 35358687 
            35098735 35298814 35868864 36648928 37418964 
            37888955 

$$
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