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AWUS01 KWNH 141208
FFGMPD
PAZ000-MDZ000-VAZ000-NCZ000-WVZ000-TNZ000-141800-

Mesoscale Precipitation Discussion 1047
NWS Weather Prediction Center College Park MD
806 AM EDT Fri Aug 14 2026

Areas affected...Central & Southern Appalachians

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

Valid 141200Z - 141800Z

SUMMARY...Increasing westerly low-mid level winds and healthy
moisture advection will lead to developing thunderstorms along the
central and southern Appalachians this morning and persist into
the early afternoon. Flash flooding is likely, especially in areas
with highly sensitive soils and along rugged terrain.

DISCUSSION...11Z surface analysis showed a long stationary front
positioned over the OH Valley and stretching as far east as the
DelMarVa Peninsula. Doppler Radar and GOES-19 satellite depicted
an MCV over OH that was responsible for a cluster of potent
thunderstorms in southern Ohio that were making their way east
towards WV. The environment is already ripe for storms that are
likely to contain efficient warm rain processes. PWs are above
1.5" for just about the entire highlighted area, and PWs in
southern OH are topping 2". This highly saturated air-mass in OH
is being directed east within a strengthening area of westerly
850-500mb winds, which are oriented perpendicular to the mountain
range. This means better upslope enhancement in an environment
that is weakly capped and will support more additional
thunderstorms along windward facing slopes of the central and
southern Appalachians.

Developing thunderstorms will have between 500-1,000 J/kg of
MUCAPE at their disposal and 1000-500mb mean RH values are >80%.
As daytime heating increases, surface based heating will be
stronger farther south towards the Smokeys where early glimpses
from visible satellite imagery shows breaks in the cloud cover,
particularly farther upstream in eastern KY, southwest VA, and
eastern TN. In addition, freezing levels are over 15,000ft in some
cases with warm cloud layers up to 13,000ft deep. Soils are also
fairly saturated ahead of these storms with FLASH CREST soil
saturation showing between 50-75% along the Appalachians and some
isolated areas over 75%.

The blend of increasing upslope flow, anomalous PWs that will
approach 2" later this morning, and sufficient instability is
likely to result in storms that contain excessive rainfall rates
over 2"/hr in some cases. 1-hr FFGs for the majority of the
central and southern Appalachians are <1.5", and 3-hr FFGs are
even more concerning, especially in southern WV, SW VA, and
eastern TN with <2" FFGs. Storms will persist into the early
afternoon with potentially more storms later this afternoon. Flash
flooding is likely today in the central and southern Appalachians
with rugged/steep terrain most at-risk.

Mullinax

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

ATTN...WFO...GSP...LWX...MRX...PBZ...RLX...RNK...

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

LAT...LON   39748023 39717992 39687944 39637923 39477899
            39097903 38457928 37807967 37508009 37018053
            36628110 36128163 35628211 35518254 35608324
            35848348 36328325 36748290 37058253 37488190
            37748130 38068078 38758048 38998046 39208047
            39528048 39668044