923
ACUS03 KWNS 140721
SWODY3
SPC AC 140720

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0220 AM CDT Wed May 14 2025

Valid 161200Z - 171200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE OZARK
PLATEAU INTO THE OHIO RIVER VALLEY...

...SUMMARY...
Scattered strong to severe thunderstorms are expected across the
Ohio Valley region Friday afternoon and evening with more isolated
severe thunderstorms extending southwestward into northeast Texas.

...Synopsis...
A residual cold front associated with an occluding surface low over
the upper MS Valley is expected to stall across the Ozark Plateau
into the lower OH Valley region by around 12 UTC Friday. This
boundary is expected to lift northward through the day as an
effective warm front amid a persistent southerly low-level flow
regime. Aloft, a low-amplitude perturbation is expected to emanate
out of the central Plains into the mid-MS Valley. Westerly mid-level
flow associated with this wave will help mix a diffuse surface
trough/dryline across the eastern Plains through the late afternoon.
Thunderstorm development is expected along the lifting warm front
and possibly off the trough/dryline by late afternoon as lift
associated with the mid-level wave impinges on the warm sector.

...Ozark Plateau into the Ohio River Valley...
The general consensus among medium and long-range guidance is that
thunderstorms developing along the warm front and/or surface trough
ahead of the mid-level wave will mature in an environment
characterized by MLCAPE values around 3000 J/kg and effective bulk
shear values on the order of 40-50 knots. These
thermodynamic/kinematic conditions will be very favorable for
long-lived organized convection. However, disagreement among
solutions persists regarding the northward extent of the warm sector
by peak heating. Recent ECMWF/EPS runs hint at greater coverage of
ongoing showers/thunderstorms by 12 UTC Friday that will likely
inhibit northward advancement of the warm front. Conversely,
NAM/GFS/GEFS all depict less early-morning convection and thus lift
the boundary well north into southern IL/IN/OH with a more expansive
warm sector. As such, the envelope of potential outcomes remains
somewhat broad. Regardless, some combination of scattered supercells
and organized clusters, including the potential for a long-lived MCS
as hinted by some deterministic solutions, appears likely somewhere
across the Ozarks/OH Valley region Friday afternoon and evening.

...Southwest Arkansas into northeast Texas...
Thunderstorm initiation along a sharpening dryline appears probable
Friday afternoon/evening from southwest AR into northeast TX based
on recent ensemble QPF signals. While displaced from the stronger
mid-level flow and forcing for ascent to the north, sufficient
buoyancy and deep-layer shear should be in place to support isolated
supercells across the region with an attendant hail/wind threat.

..Moore.. 05/14/2025

$$