Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0655 AM CST Wed Dec 17 2025

Valid 171300Z - 181200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHWEST AND NORTHERN INTERMOUNTAIN REGION...

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

...Northwest/Northern Intermountain region...
A progressive/vigorous shortwave trough will continue to modestly
amplify and otherwise race east-southeastward from the
Washington/British Columbia border vicinity this morning to the
northern Plains tonight. Intense deep-tropospheric flow (highlighted
by 55-85 kt at 700 mb) will accompany this wave, yielding widespread
high winds across much of the Northwest to the northern Great
Plains.

Low-topped convection, occasionally capable of lightning and
semi-organized line segments, will continue in association with the
east/southeastward-advancing cold front, with convection potentially
expanding by late morning towards the Snake River Plain/Yellowstone
vicinity and potentially other parts of the northeast Great Basin by
afternoon. Surface-based instability will be very limited, but some
convectively enhanced wind gusts may occur.

..Guyer/Lyons.. 12/17/2025