425
FXUS65 KPIH 070538
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1038 PM MST Sat Dec 6 2025

.KEY MESSAGES...

- Light rain and snow picks up again Sunday afternoon for many
  locations. Precipitation threat continues each period through
  at least Thursday.

- Windy to very windy conditions should peak today in the Snake
  River plain/eastern Magic Valley/southern hills and subside by
  evening.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 133 PM MST Sat Dec 6 2025

Satellite imagery shows fast northwest flow still in place over
East Idaho, and there is little upstream to significantly change
this pattern. Across East Idaho, mid level cloud cover drapes
the mountain areas, and a few showers remain possible this
evening into tonight. Accumulations should remain minimal, with
little to no impact. Gusty winds across the south expected to
continue to diminish through the evening. Next shortwave
upstream arrives Sunday, with showers increasing throughout the
day and continuing through Sunday night. Temperatures at lower
elevations remain mild, with rain or a rain/snow mix up to about
5000 ft. Snow levels could be slightly higher across the South
Hills and Albion mountains. The focus for precipitation will
remain focused across the western edges of the central mountains
along and near the Sawtooths, and along the highlands between
I-15 and the WY border. Model probabilistic spread supports 2-6"
across the higher elevations, potentially impacting Galena
Summit, Pine Creek Pass, and the Island Park region. No winter
related headlines are anticipated at this time.

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 133 PM MST Sat Dec 6 2025

Main feature and impacts in the initial time frame of the long term
will be an extended atmospheric river event with large quantities of
Pacific moisture transported into Idaho from the Pacific northwest.
Heaviest precipitation will likely be Tuesday and Wednesday.  There
is high chances of over 1 inch qpf mainly in the Sawtooths, central
mountains and eastern mountains.  It will be an extremely warm event
with snow levels beginning at 6 to 7 thousand feet Monday rising to
7500 to 8500 feet Wednesday.  So any heavy snow accumulations are
expected to be well above 7 thousand feet with widespread rain
likely in lower elevations in the Monday through Wednesday period.
Highs in the Monday through Saturday period will be extremely warm
as much as 15 degrees above normal mainly in the 40s and into the
mid 50s lower elevations.  Windy conditions expected Tuesday through
Thursday in this pattern especially in the Snake River Plain.
Travel impacts in this event are mainly expected at pass levels
where the heaviest snow will occur, but as mentioned snow levels
will be extremely high through the week.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1038 PM MST Sat Dec 6 2025

Only a few minor tweaks/nudges needed for the 06z TAFs looking
through Sunday evening. The 00z suite of HREF CAMs did little to
increase our confidence in timing/placement of any organized
rain/snow shower activity Sunday afternoon and evening. In fact, if
anything, the picture has trended a bit drier with even less overall
agreement. Thus, we maintain VCSH only everywhere except MVFR -SHSN
at KDIJ. Conceptually, this does match our big-picture expectations
that moist northwest flow over the next several days will mostly
target some of our mountain ranges for significant QPF. Some
additional lowering of cigs is possible Sunday night. Previous
discussion is below.

Issued at 438 PM MST Sat Dec 6 2025

Other than wrapping up a few more snow showers near KDIJ through
05z/10pm, all terminals will see VFR conditions this evening and
tonight. There is a low chance of low stratus developing near KIDA
with mixed signals in the guidance, but confidence is low, and have
only hinted at development for now with FEW015. Clouds
increase/thicken again Sunday as some more moisture heads our way on
northwest flow. Some CAMs are generating bonafide showers over
portions of the forecast area by afternoon, but for now have gone
VCSH everywhere but KDIJ where at least MVFR conditions are expected
with snow showers. Will continue to monitor trends/agreement in high-
res guidance for precip potential Sunday.

&&

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

&&

$$

SHORT TERM...DMH
LONG TERM...GK
AVIATION...01