235
FXUS65 KPIH 162101
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
201 PM MST Tue Dec 16 2025

.KEY MESSAGES...

- Widespread high winds Wednesday ahead of and behind cold
  frontal passage

- Widespread valley rain and mountain snow Wednesday

- Moderate to heavy mountain snow Thursday and Friday

&&

.SHORT TERM /THROUGH WEDNESDAY NIGHT/...
Issued at 133 PM MST Tue Dec 16 2025

Afternoon satellite imagery shows fast moving mid/high level clouds
streaking across the area today with some occasional breaks in
sunshine observed. Temperatures remain well above seasonal norms
with upper 40s to low 50s in place but the area is mostly void of
precip, for the moment. This will change drastically over the next 6-
12 hours as a deep surge of Pacific moisture moves through the
region in association with a shortwave to our north and and an
associated cold front. A very active Wednesday is in store for all
of eastern Idaho with widespread precipitation along with strong,
gusty winds ahead of and behind the cold front. As far as winds are
concerned, upgraded the High Wind Watch to a High Wind Warning for
most eastern Idaho zones while adding the others to a Wind Advisory.
NBM/HREF probabilities show a 50-70% chance of max gusts exceeding
60 mph across MUCH of the warned area, including the I-15 and I-
84/86 corridors with those probabilities even higher across the INL.
If you lower this criteria to 50 mph it`s more like 80-100% for many
of the aforementioned areas. So it`s going to be a VERY windy day
tomorrow. It`s not a guarantee that everyone in the warned area that
will see official High Wind "criteria" which is 58+ mph gusts but
it`ll be close enough that the Warning certainly feels justified.
Areas in the Wind Advisory will still be breezy, with gusts upwards
of 40-45 mph and this is primarily across the far SE corner of the
region.

On the precipitation front, expect precip to overspread the area
during the overnight hours and towards daybreak Wednesday. Snow
levels remain very high at the onset of the event, 7500-8000 feet,
but will come crashing down to valley floors by mid/late afternoon
as the front pushes through the area. By the time they do however,
most of precip will likely be winding down across the Snake Plain
and Magic Valley but a brief period of a rain/snow mix or even all
snow is certainly possible as temperatures will be dropping rather
quickly. Snow accumulations are limited to the highest terrain with
this precip tomorrow with an inch or so, at best, around Stanley and
Island Park but the higher terrain in the central mountains and
eastern highlands will see more. Lows overnight Wednesday into
Thursday will drop below freezing throughout the region so it`s not
out of the question that some wet roadways could briefly ice over.
Valley lows will only be a few degrees below freezing however so
this isn`t a sure bet. The one thing that is certain, is that it`s
going to be a wet, windy Wednesday across the area!

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
Issued at 133 PM MST Tue Dec 16 2025

The next round of precipitation will reach central Idaho during
the early hours of Thursday and spread further east during the
afternoon. Temperatures and snow levels will rebound rapidly on
Thursday, with temperatures warming back into the 30s and 40s
across the low to mid- elevations and into the 40s and 50s later
week.

Locations above 7,000 feet will receive another two to three feet of
snow in the central mountains over 48 hours on Thursday and Friday,
including up to around two feet on Galena Summit. Snow levels being
high again, the mountain valleys will receive light to moderate
snow, with 4 to 6 inches forecast for Stanley and Ketchum. While
winds will not be as strong as those anticipated Wednesday, portions
of the region will see 35 to 45 mph gusts. This is not the end of
the snow for our mountains however, with light snow rates forecast
in the high terrain to continue into early next week.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1129 AM MST Tue Dec 16 2025

We continue to refine timing of precipitation and increasing winds
based on model guidance. Have forecast MVFR CIGs and VIS during
periods of light to moderate rain or snow as strong winds will
accompany precipitation. As snow levels drop behind the cold front
Wednesday, precipitation will transitions from rain to snow at KSUN,
with models indicating the timing of transition to be approximately
18z. Some model guidance is suggesting IFR conditions at KIDA
beginning early Wednesday but confidence remains low and have
therefore held with MVFR. Additionally, LLWS will likely need to
be added in future forecasts.

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
High Wind Warning from 5 AM to 5 PM MST Wednesday for
IDZ051>058-062-064>075.
Wind Advisory from 5 AM to 5 PM MST Wednesday for IDZ059>061-
063.
Winter Storm Watch from late Wednesday night through late
Friday night for IDZ071>074.into
the weekend

&&

$$

SHORT TERM...McKaughan
LONG TERM...Cropp
AVIATION...Cropp