871
ACUS01 KWNS 230522
SWODY1
SPC AC 230521

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1221 AM CDT Thu Jul 23 2026

Valid 231200Z - 241200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
WESTERN KANSAS...

...SUMMARY...
Widely scattered severe storms capable of severe wind gusts and
large hail are possible over portions of the central and southern
High Plains Thursday afternoon and evening. More isolated
occurrences of damaging wind are possible from the middle Texas
coast into Deep South Texas, the eastern Carolinas, and parts of the
Columbia Basin into the northern Rockies.

...Synopsis...

A short-wave trough over the central Rockies late this evening is
forecast to progress slowly into the central High Plains by Thursday
afternoon, within the northeast periphery of a strengthening
mid/upper-level high over the southern Rockies. Downstream from
those developments, a short-wave trough will translate through New
England with a trailing vorticity ribbon and associated belt of
enhanced mid-level flow across the southern Mid-Atlantic. Elsewhere,
Tropical Storm Bertha is forecast to advance from just off the
southwest LA coast to the middle TX coast by Thursday evening.

At the surface, a stationary front currently extending from the CO
Front Range through the OK and TX Panhandles into the Red River
Valley is forecast to drift north through portions of western KS on
Thursday immediately ahead of a thermal low/lee cyclone over
southeast CO and southwest KS. A dryline will extend south from the
surface low-front triple point into the central or eastern OK and TX
Panhandles by mid- to late afternoon.


...Central and southern High Plains...

Strong boundary-layer heating is forecast in the vicinity of the
surface front and dryline Thursday afternoon with temperatures in
the mid 90s to around 105. The hot temperatures will combine with
dewpoints in the mid 50s to mid 60s and modestly steep mid-level
lapse rates to yield a narrow axis of moderate instability with
MLCAPE of 1500-2500 J/kg. Forcing for ascent preceding the
short-wave trough is expected to contribute to isolated to widely
scattered thunderstorms by mid afternoon from the vicinity of the
thermal low in southeast CO to along the front and dryline from
northeast CO into the OK and TX Panhandles.

Forecast soundings along the front indicate a vertically veering
wind profile with 30-35 kt of deep-layer shear, which will be
sufficient for at least episodic supercell structures with a risk
for large hail. In contrast, the storms forming in the hot, deeply
mixed air mass west of the boundary are more likely to produce
sporadic severe wind gusts. A corridor of potentially more
concentrated severe wind gusts may materialize across portions of
southwest KS by evening, where a number of the 00z CAMs indicate the
evolution of an organized cold pool.


...Middle Texas Coast to Deep South Texas...

A channel of enhanced mid-level flow is forecast to precede Bertha
atop a hot and moist boundary layer, with moderate instability
developing by afternoon along the middle TX coast. Similar to
Wednesday, widely scattered thunderstorms are expected during the
afternoon within an environment characterized by 30-40 kt of
deep-layer shear, steep low-level lapse rates, and high PW content.
As such, the potential will exist for locally damaging downburst
winds as storms spread southwest along the coast into Deep South TX
during the afternoon and evening hours.


...Columbia Basin into northern Rockies...

Mid/upper-level winds are forecast to strengthen across the area on
Thursday in tandem with a subtle disturbance moving through portions
of OR and WA. Daytime heating along favored terrain in conjunction
with the glancing influence of the passing disturbance will aid in
isolated to widely scattered thunderstorms by mid afternoon within a
moderately unstable and steep lapse rate environment. The
strengthening upper-level winds will enhance vertical shear,
supporting the potential for some storm organization with an
associated risk for locally damaging wind gusts and marginally
severe hail.


...Eastern Carolinas...

Thunderstorms are expected to be ongoing at 12Z Thursday along a
west-to-east-oriented front in NC. Breaks in the clouds south of the
early-day storms will combine with a moist boundary layer to yield
an axis of moderate instability by afternoon across portions of
southeast NC into far eastern SC. A corridor of more concentrated
thunderstorm development is possible in that area, near the
intersection of the outflow from the morning storms with the
sea-breeze boundary. Modest deep-layer shear will coincide with
steepening low-level lapse rates and high PW content to yield
locally intense wet microbursts capable of damaging winds.

..Mead/Weinman.. 07/23/2026

$$