869
ACUS11 KWNS 212148
SWOMCD
SPC MCD 212148
WVZ000-VAZ000-KYZ000-OHZ000-TNZ000-INZ000-ILZ000-MOZ000-212345-

Mesoscale Discussion 1699
NWS Storm Prediction Center Norman OK
0448 PM CDT Tue Jul 21 2026

Areas affected...Kentucky into northern Tennessee and far western
Virginia

Concerning...Severe Thunderstorm Watch 508...

Valid 212148Z - 212345Z

The severe weather threat for Severe Thunderstorm Watch 508
continues.

SUMMARY...The potential for damaging winds, large hail, and perhaps
a tornado or two is expected to spread south of the watch area
between 23Z and 00Z. A new watch will be required prior to that
time.

DISCUSSION...Regional radar imagery shows a mix of supercells and
bowing structures ongoing across eastern and central parts of the
watch area with more recent storm development present near the
confluence of the Mississippi and Ohio Rivers. The inflow air mass
to the storms is warm and quite moist with MLCAPE of 2500-3500+
J/kg, per recent objective analysis. However, considerable downshear
anvil blowoff has limited the potential for stronger insolation
across the warm sector, which in turn is resulting in relatively
poor low-level lapse rates. Kinematically, regional VWPs are
sampling seasonably strong mid- and high-level winds and resultant
deep-layer shear with the strongest low-level shear currently
analyzed from eastern KY into western WV.

Extrapolation of current storm motions takes the storms to the
southern edge of the watch area between 23Z and 00Z with latest CAM
guidance suggesting the storms will remain intense as they continue
into portions of TN and far western VA. That scenario appears
reasonable given the presence of the strong vertical shear. Expect
the continuation of supercell and bowing structures with the primary
hazards being damaging winds and large hail. The extent of the
longer-term tornado threat remains somewhat uncertain owing to the
weaker low-level lapse rates, which may limit near-ground parcel
accelerations. However, in the near-term, the greatest tornado risk
will extend from the tornadic supercell in Hart County KY, into
eastern KY where low-level shear is the strongest.

..Mead.. 07/21/2026

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...RLX...MRX...JKL...ILN...LMK...OHX...PAH...MEG...

LAT...LON   36228986 36678976 37848656 38748303 38308240 37598192
            36858211 36248375 35928569 36118836 36218938 36228986

MOST PROBABLE PEAK TORNADO INTENSITY...85-110 MPH
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN