647
ACUS02 KWNS 190547
SWODY2
SPC AC 190546

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1246 AM CDT Sat Sep 19 2026

Valid 201200Z - 211200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
CENTRAL INTO EASTERN OKLAHOMA AND THE COLORADO FRONT RANGE...

...SUMMARY...
A few severe wind and hail producing thunderstorms are possible over
eastern Colorado, with severe gusts also likely to accompany storms
over portions of Oklahoma tomorrow (Sunday). Isolated severe
thunderstorms are also possible from the Ozark Valley to the central
Appalachians.

...Synopsis...
Multiple mid-level impulses will pivot around a de-amplifying upper
ridge and traverse the central CONUS tomorrow (Sunday). These
impulses will encourage the gradual southward progression of a
surface cold front, preceded by a seasonably moist and unstable
boundary layer, to support thunderstorm development across much of
the southern Plains to the OH Valley. Given stronger buoyancy in
proximity to the cold front, severe thunderstorms are possible,
especially over the southern Plains. Upslope flow along the western
flank of the cold front into the central High Plains will encourage
a severe threat in this region as well.

...Southern Plains...
Some cloud cover, along with widely scattered showers and
thunderstorms, may be in place across portions of the southern
Plains into the Ozarks by Sunday morning. As such, there are some
uncertainties regarding how these initial conditions will impact
downstream convective evolution. Nonetheless, guidance consensus
suggests that surface temperatures will warm ahead of the front into
the 90s F, with 70 F dewpoints, yielding 2500-3500 J/kg MLCAPE amid
waning inhibition. This will support thunderstorm initiation by mid
to late afternoon. Given mediocre vertical shear profiles, storms
should quickly merge and become outflow dominant. However, given the
potential for strong buoyancy, a short-lived cold-pool-driven MCS
may develop, accompanied by a focused severe gust threat in
central/eastern OK.

...Portions of MO into the OH Valley and central Appalachians...
Isolated to widely scattered thunderstorm development is likely all
along the cold front and periphery of the decaying upper ridge, from
the Ozarks to the central Appalachians, during the afternoon given
boundary-layer destabilization. The convergence of upper 60s F
dewpoints along the front will boost MLCAPE to over 2000 J/kg. A few
of the stronger multicellular complexes may produce a couple
instances of severe wind/hail, though the severe threat should be
limited to some degree given mainly 6 C/km mid-level lapse rates and
mediocre vertical wind shear.

...Portions of eastern Colorado...
Along the western flank of the cold front, upslope flow into eastern
Colorado during the afternoon, will encourage scattered thunderstorm
development. Notable veering flow above the boundary layer, along
with increasing westerly flow through the remainder of the
troposphere, will result in elongated hodographs and 40-50 kts of
effective bulk shear. A few of the stronger storms should become
supercellular. Given 7-8 C/km mid-level lapse rates, supercells may
be accompanied by both severe wind and hail.

..Squitieri.. 09/19/2026

$$