810
ACUS01 KWNS 192004
SWODY1
SPC AC 192003

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0303 PM CDT Sat Sep 19 2026

Valid 192000Z - 201200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL PLAINS AND CENTRAL HIGH PLAINS...

...SUMMARY...
Thunderstorms with scattered severe wind gusts and large hail are
possible this afternoon and evening across parts of the central
Plains.

...20z Update...

...Central High Plains into western Kansas...
Latest CAM and TLE guidance continue to provide some indications
that a linear cluster or two will persist into western, and perhaps
even central Kansas, after 00z tonight. This may allow a somewhat
greater risk for hail/wind gusts to persist farther west into
Kansas. Uncertainty regarding the evolution and downstream
persistence of these clusters through the overnight hours precludes
further expansion at this time, however.

...Central New Mexico...
Widely scattered thunderstorms with some marginal supercell
structures have formed across portions of central New Mexico over
the past 1-2 hours. The 18z ABQ observed sounding depicted around
750 J/kg MLCAPE with ~30 kts of effective shear and 700-500 mb lapse
rates around 7 C/km. While this could support a brief/localized
threat for damaging wind gusts and marginally severe hail,
observations and recent CAM/TLE guidance suggest the
spatial/temporal window for any localized severe risk remains quite
narrow. Thus, the general severe risk appears to be less than 5%
across this region.

...Ohio Valley...
Latest observations continue to depict a well defined outflow
boundary arching southwestward from north of Columbus, OH, into
southern IL/IN. Convection has largely struggled to sustain along
this boundary, likely owing to the surging character of the outflow
and limited deep-layer wind shear. The northern edge of the Level
1/Marginal Risk area was trimmed slightly where temperatures well
behind the outflow boundary have fallen into the upper-70s F and are
thus expected to limit further convective development this
afternoon/evening.

Elsewhere, the forecast remains generally on track, with only minor
changes made to the existing outlook. See the discussion below and
MCDs #2309 and #2310 for additional information.

..Chalmers/Wendt.. 09/19/2026

.PREV DISCUSSION... /ISSUED 1129 AM CDT Sat Sep 19 2026/

...Ohio Valley...
Recent surface analysis places a weak low over northern IN, along
the northern end of an outflow boundary that is pushing
southward/south-southeastward across central IL and central IN.
Airmass south of this boundary is very moist, with dewpoints
generally in the upper 60s to low 70s. Filtered heating is
anticipated across this region today, with the resulting warm and
moist conditions supporting moderate buoyancy. The strongest
buoyancy is expected from southern IN into southwest OH and adjacent
far northern KY. The surging character of the outflow combined with
limited deep-layer vertical shear results in uncertainty regarding
how thunderstorms will evolve this afternoon, with at least some
potential for a predominance of undercut, poorly organized updrafts.
That being said, potential also exists for just enough
buoyancy/shear balance for a few stronger, more persistent bowing
clusters. Steep low-level lapse rates will promote strong to severe
gusts with any more persistent line segments that develop.

...Southern Appalachians/Southeast...
Warm and moist conditions will support airmass destabilization and
the potential of afternoon/evening thunderstorms across the region.
The region is largely void of coherent surface features, so any
convective initiation would likely be tied to mesoscale areas of
low-level confluence. Widely scattered to scattered storms are
forecast during the afternoon, and a few stronger water-loaded
downdrafts capable of 50 to 60 mph gusts are possible.

...Central and Southern Plains/Lower Missouri Valley...
Recent surface analysis places a low over southwest IA, with a cold
front extending back southwestward through southwest KS and the
central OK Panhandle into the northwest TX Panhandle. This front is
expected to slowly push south while larger-scale mid-level troughing
over the Great Basin and central Rockies gradually shifts eastward.
A seasonably moist airmass is in place ahead of the cold front, and
moderate buoyancy is expected as this airmass heats and destabilizes
this afternoon.

Low-level convergence along the cold front, augmented by modest
large-scale forcing for ascent, will support scattered storm
development during the late afternoon and early evening as
convective inhibition is locally eroded. Given adequate speed and
directional shear, a few short-lived supercells are possible early
in the convective cycle, particularly across KS. Large hail will be
possible with the stronger updrafts. Thereafter, high-based storm
character coupled with steep low-level lapse rates will support
strong to severe gusts, including the potential for a few gusts of
60 to 75 mph.

...Central High Plains...
Low-level easterly flow across the central High Plains will help
maintain at least upper 50s/low 60s dewpoints across the region this
afternoon/evening. The low-amplitude shortwave trough currently
moving through northern NV/UT is forecast to continue eastward,
interacting with this moist and unstable airmass to support
scattered thunderstorm development. With time, strengthening
mid-level flow will help support upscale growth from a loosely
organized band of a storms (including some supercells) to a more
organized linear cluster. Some hail is possible early with the more
cellular development, with wind gusts becoming more likely with
time. There is some indication this activity may continue into
western KS during the late evening and early overnight.

$$