SPC AC 181941
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0241 PM CDT Mon Oct 18 2021
Valid 182000Z - 191200Z
...NO SEVERE THUNDERSTORM AREAS FORECAST...
The risk for severe thunderstorms appears negligible across the U.S.
today through tonight.
No updates are necessary to the previous outlook.
.PREV DISCUSSION... /ISSUED 1128 AM CDT Mon Oct 18 2021/
Upper-level low pressure will move east over the Great Basin region
towards the central/northern Rockies through tonight, preceded by
height falls/large-scale lift and mid-level moistening. Showers and
isolated thunderstorms are expected to develop in association with
the upper low this afternoon. With a dry boundary layer in place,
pockets of stronger heating this afternoon may result in a favorable
environment for locally gusty winds and perhaps hail, especially
over northern UT and adjacent areas of ID/WY/CO. An overall lack of
more substantive low-level moisture should preclude an organized
A low-amplitude perturbation over northern Mexico will approach West
TX this afternoon, interacting with a deep mixed layer and modest
instability (MLCAPE of a few hundred J/kg). Isolated to widely
scattered high-based thunderstorms are expected this afternoon, with
the potential for gusty winds with an isolated stronger storm given
the dry sub-cloud environment.
Elsewhere, a dry/stable air mass should preclude thunderstorm
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