405
FXUS65 KPIH 300711
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1211 AM MST Tue Dec 30 2025

.KEY MESSAGES...

- High pressure rebuilds across the western U.S.

- Dry conditions and warmer conditions through New Year`s Eve

- Rain and snow rings in 2026

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 1210 AM MST Tue Dec 30 2025

Dry and warmer conditions will help bring 2025 to a close.
Inversions will persist, and where we can remain mixed or
above/within the inversion layer...highs will be in the upper
30s and 40s. That puts us in some areas 10-15 degrees ABOVE
AVERAGE. It doesn`t look any major issues with fog or stratus
is expected at the moment. Don`t be surprised though if
something localized develops due to plummeting temperatures at
night allow humidity to get closer to 100%. For New Year`s Eve,
the ridge slides far enough east to allow moisture to return
across central and eastern Idaho. We will see showers across
higher elevations south of the Snake River, especially across
the South Hills and Albion Mountains.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Issued at 1257 PM MST Mon Dec 29 2025

New Year`s Day still has positive height anomalies with
troughing attempting to break down this ridge coming up from
California; By 2/00Z it is still offshore of California in 50
percent of the solutions. For Fri/3 Jan only around 30 percent
of the solutions have a cluster with a flattened upper level
flow over the Gem State. About half the solutions have set up a
pattern close to a Atmospheric River event. The remaining 20
percent have the low still farther west and less likely for
precipitation reaching Idaho. All of this indicates warmer than
normal temperatures and a threat of rain and snow by the 2nd.
Afternoon highs in the NBM are running 6 to 13 deg F above
normal, and once cloud cover arrives on New Year`s Day mild
overnight lows 9 to 15 deg F above normal for the time of year.
Wind appears slightly elevated but not even to the "windy"
category of 20 to 30 mph wind, more like "breezy" at best,
starting Fri afternoon.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1029 PM MST Mon Dec 29 2025

VFR conditions forecast at all terminals under high pressure
with generally light and variable winds. FEW mid to high level
clouds will return tonight into Tuesday morning, but skies will
clear again during the afternoon. Models indicate only a 10% or
less chance of CIGs below 1k ft.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
None.

&&

$$

SHORT TERM...Keyes
LONG TERM...Messick
AVIATION...Cropp