105
AWUS01 KWNH 171709
FFGMPD
NCZ000-SCZ000-GAZ000-TNZ000-KYZ000-ALZ000-172310-

Mesoscale Precipitation Discussion 0754
NWS Weather Prediction Center College Park MD
108 PM EDT Fri Jul 17 2026

Areas affected...Southern KY...Eastern TN...Southern Appalachians

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

Valid 171710Z - 172310Z

SUMMARY...Pulse thunderstorms capable of producing torrential
rainfall rates up to 3"/hr could lead to areas of flash flooding
this afternoon.

DISCUSSION...The Tennessee Valley, Cumberland Plateau, and as far
east as the southern Appalachians have started seeing
thunderstorms blossom throughout these region. Surface dew points
are in the low-mid 70s with some spotty upper 70s dew points. RAP
mesoanalysis shows juicy PWs surpassing 2" over the TN Valley and
Cumberland Plateau, but closer to 1.5-1.75" in the southern
Appalachians. Strong surface based heating has led to MLCAPE
values to range between 2,000-3,000 J/kg, providing developing
thunderstorms with no shortage of available instability. RAP model
soundings show warm cloud layers at least 14,000ft deep in the TN
Valley, giving storms an ideal environment to be highly efficient
rainfall producers.

850-300mb mean layer winds are light (<10 kts) and very little
vertical wind shear is present, forcing storms to be more
pulse-like in nature. Additional storms will form via outflow
boundaries that traverse these regions and collide with
neighboring outflows and elevated terrain. Given the PWs and
instability present, rainfall rates up to 3"/hr will be possible
and 1-hr FFGs in some areas (Cumberland Plateau, southern KY,
eastern TN) are <2". Flash flooding is possible this afternoon
given the brief yet intense rainfall rates storms will be capable
of producing. Areas along complex terrain and residing within poor
drainage areas are most at-risk.

Mullinax

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

ATTN...WFO...BMX...FFC...GSP...HUN...JKL...LMK...MRX...OHX...
PAH...

ATTN...RFC...ALR...ORN...TIR...NWC...

LAT...LON   37758458 36858381 36148360 35708277 34708292
            34298440 34268585 34608695 35368747 36608758
            37558704