Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
1145 PM CST Tue Dec 16 2025

Valid 171200Z - 181200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN PARTS OF THE
NORTHWEST...

...SUMMARY...
Sporadic severe gusts may accompany low-topped convection across
parts of the Northwest this morning into midday.

...Northwest...
A vigorous shortwave trough will move quickly east along the
Canadian border from WA to the northern Great Plains by evening.
Intense tropospheric flow will accompany this wave, yielding
widespread high winds across much of the Northwest to the northern
Great Plains. Deep lee surface cyclone over southern AB should reach
the Red River Valley of the North. Attendant Pacific cold front will
sweep east with a tight pressure gradient in its wake. 

Low-topped convection may be ongoing at 12Z along the Columbia Basin
portion of the front. Most guidance also suggests an increase in
low-topped convection should occur towards late morning across parts
of the Snake River Plain as the front pushes east. Surface-based
instability will remain scant in both regimes with morning
temperatures in the 40s to low 50s. Despite the cool temperatures,
this may be sufficient for sporadic lightning flashes amid strong
large-scale ascent. With very strong surface winds accompanying the
front, both regimes could be coincident with severe wind gusts.

The bulk of sustained severe wind speeds should become primarily
confined along/east of the Rockies in MT to the CO Front Range this
afternoon per HREF/REFS guidance. However, potential for severe
convective gusts appears too conditional with negligible
surface-based buoyancy anticipated.

..Grams/Wendt.. 12/17/2025