ACUS11 KWNS 271631
SWOMCD
SPC MCD 271631
MDZ000-VAZ000-NCZ000-WVZ000-OHZ000-KYZ000-271830-

Mesoscale Discussion 0875
NWS Storm Prediction Center Norman OK
1131 AM CDT Wed May 27 2026

Areas affected...portions of the Ohio valley and Mid Atlantic

Concerning...Severe potential...Watch possible

Valid 271631Z - 271830Z

Probability of Watch Issuance...60 percent

SUMMARY...Scattered to numerous thunderstorms are expected this
afternoon across parts of southern OH and northeastern KY into WV
and the DelMarVA. A mixed storm mode should promote a risk for
damaging gusts, though some hail is also possible. One or more
severe thunderstorm watches will probably be issued in the next
couple of hours.

DISCUSSION...As of 1630 UTC, visible and radar imagery showed
initial thunderstorms gradually intensifying over the OH Valley with
clearing and deepening cumulus farther east. Weak ascent from a
broad upper trough over the northern Great Lakes is overspreading an
east-west frontal zone amidst midday heating. To the south of the
front, a very moist air mass is in place with dewpoints in the low
70s F. As surface temperatures warm near 80 F, destabilization
should continue this afternoon. Despite modest mid-level lapse
rates, 1000-1500 J/kg of MLCAPE and little inhibition will allow for
scattered to widespread thunderstorms.

A belt of enhanced westerly flow associated with the upper trough
will continue to shift eastward near the front supporting modest
deep-layer shear around 20-25 kt. Initial storms over OH and KY are
likely to be multi cellular with brief organization potential and
some clustering. As deep-layer shear increases to 30-35 kt over WV
and the Mid Atlantic states, a few marginal supercell structures and
some linear segments are also possible.

As thunderstorms develop and eventually cluster, damaging gust
potential should increase this afternoon over the OH Valley, with
additional development and the severe threat spreading eastward with
time. The brief stronger updrafts may also pose a risk for some
hail, but mid-level temperatures and lapse rates are not overly
favorable. Hail potential may be maximized with any storms that
remain more discrete.

Confidence in a sustained severe risk is highest farther east where
the best overlap of deep-layer shear and buoyancy are expected
(WV/VA into southern MD/DE). Given the expected increase in severe
potential this afternoon, a WW is possible in the next couple of
hours.

..Lyons/Gleason.. 05/27/2026

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

ATTN...WFO...AKQ...LWX...RAH...RNK...PBZ...RLX...JKL...ILN...

LAT...LON   37388207 38458274 38908272 39778148 39838111 39277960
            38747775 38487633 38387501 36917591 36317558 36257640
            36407905 37388207

MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN