ACUS01 KWNS 141250
SWODY1
SPC AC 141249

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0749 AM CDT Mon Apr 14 2025

Valid 141300Z - 151200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
INTO EARLY TONIGHT FROM EASTERN KENTUCKY ACROSS WEST VIRGINIA INTO
CENTRAL VIRGINIA...

...SUMMARY...
Scattered strong to severe storms are expected this afternoon
through early tonight from the Upper Ohio Valley eastward to the
Mid-Atlantic. Large hail, severe wind gusts, and a couple of
tornadoes will be possible.

...Upper OH Valley this afternoon into VA early tonight...
An initial shortwave trough and surface cyclone will occlude by
tonight between Lake Superior and James Bay, as an upstream
shortwave trough digs southeastward from the northern Plains toward
the OH Valley. An associated surface cold front will move
southeastward across the OH Valley today, while a corridor of
moisture return occurs ahead of the front from the Mid-South to WV.
Surface heating in cloud breaks will drive temperatures into the 70s
by early-mid afternoon, coincident with northeastward advection of
55-60 F boundary-layer dewpoints beneath the northeastward extent of
an elevated mixed layer. Though the upstream moisture source is
rather modest by mid April standards, recent green up and unusually
moist ground across the OH Valley will augment evapotranspiration.
These processes will result in MLCAPE of 1000-1500 J/kg with minimal
convective inhibition as low-level ascent focuses along the front.

Thunderstorm development is expected by mid afternoon in a broken
band along the cold front from northern KY into southern OH, and
storms subsequently expand in coverage while spreading
east-southeastward across WV into VA through early tonight. The
moderate buoyancy and long hodographs will support supercells
capable of producing large hail of 1-2 inches in diameter, and
damaging winds of 60-75 mph are also expected, especially with any
upscale growth into bowing segments. Low-level shear/hodograph
curvature will be sufficient for some tornado threat, though this
will be modulated by the degree of low-level moistening.
Clusters/line segments will persist east of the Appalachians into VA
through early tonight, though the severe threat will diminish with
eastward extent and after 03z.

...SD to IA this afternoon/evening...
Despite limited low-level moisture, surface heating beneath cooling
midlevel temperatures will support weak surface-based buoyancy and
the potential for low-topped thunderstorms from SD into IA (in
advance of the digging shortwave trough now over western ND/eastern
MT). Relatively cold temperature profiles will favor some threat
for small hail, while steep low-level lapse rates and 30+ kt flow
through the mixed layer favor gusty outflow winds of 40-50 mph.

..Thompson/Dean.. 04/14/2025

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