727
ACUS01 KWNS 171612
SWODY1
SPC AC 171610

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1110 AM CDT Thu Sep 17 2026

Valid 171630Z - 181200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
AND EVENING OVER PARTS OF IDAHO/UTAH...AND A SMALL PART OF THE
CENTRAL HIGH PLAINS....

...SUMMARY...
Thunderstorms with isolated severe wind gusts and hail will be
possible over parts of the Intermountain West this afternoon and
evening. A few strong to severe gusts may also occur across portions
of the central High Plains.

...ID/UT...
Morning water vapor imagery shows an upper low over northern CA,
with a band of strong flow aloft with associated embedded shortwave
troughs extending across NV into UT/ID.  Strong heating across this
area will aid in the development of scattered thunderstorms from
southern ID into northern UT by mid-afternoon.  Sufficient vertical
shear is present for rotating updrafts capable of large hail and
gusty/damaging winds.  While coverage of storms will likely be
limited, one or two severe cells are expected later today - mainly
over the eastern Snake River Plain.

...CO/KS/NE...
The remnants of a weak tropical low are tracking northeastward
across the four-corners region this morning.  Ample moisture and
weak ascent associated with this feature will lead to considerable
clouds and scattered thunderstorms today over the mountains of CO
and southern WY.  This activity will spread eastward into eastern CO
and western NE/KS with high-based convection posing a risk of
locally damaging wind gusts.  The extent of this severe threat will
be modulated by daytime heating, which is uncertain at this time due
to lingering cloud cover.

..Hart/Chalmers.. 09/17/2026

$$