170
ACUS02 KWNS 221721
SWODY2
SPC AC 221719

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1219 PM CDT Tue Sep 22 2026

Valid 231200Z - 241200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
EASTERN TN AND VICINITY...

...SUMMARY...
Strong to locally severe storms are possible across parts of eastern
Tennessee and vicinity on Wednesday.

...Eastern TN and vicinity...
A mid/upper-level trough will remain in place over most of the East
on Wednesday. A reinforcing shortwave trough and attendant jet
maximum are forecast to move from the lower Ohio Valley toward the
southern Appalachians through the day. A narrow zone of moderate
destabilization is expected to develop during the afternoon from
northeast AL into eastern TN and southeast KY, in the vicinity of an
inverted surface trough. The approaching shortwave trough and
terrain-related circulations will result in thunderstorm development
during the afternoon.

The greatest storm coverage is currently expected in the vicinity of
eastern TN, where effective shear will generally be in the 25-30 kt
range, with modestly elongated mid/upper-level hodographs. The
environment will support at least brief storm organization, with
localized hail and strong/damaging gusts possible. A
Level-1/Marginal Risk has been added where relative confidence is
highest in strong diurnal storm development. Deep-layer shear will
be somewhat stronger into central AL/west-central GA, though
substantial midlevel dryness and warmer temperatures aloft may tend
to limit storm coverage with southward extent.

...Northern High Plains...
A mid/upper-level shortwave trough will move across the Dakotas on
Wednesday. The relatively early timing of this system will not be
ideal for surface-based development later in this afternoon across
the northern High Plains, where some diurnal destabilization is
expected. Isolated strong storm development cannot be ruled out in
this area, while generally weak elevated convection is expected
farther east across the eastern Dakotas into MN.

...Southern High Plains...
Relatively widespread convection is expected from eastern NM into
the OK/TX Panhandles, in association with a mid/upper-level trough
moving northward out of Mexico. Generally weak lapse rates and
buoyancy are expected to limit severe potential, though a strong
storm or two cannot be ruled out, given the presence of veering wind
profiles and 25-35 kt of effective shear.

..Dean.. 09/22/2026

$$