076
FXUS65 KPIH 230532
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1032 PM MST Sat Nov 22 2025

.KEY MESSAGES...

- More patchy dense fog expected tonight into Sunday morning.

- Remaining dry through the weekend before Monday cold front.

- Continued unsettled pattern and turning colder through the
  Thanksgiving weekend.

&&

.SHORT TERM /THROUGH SUNDAY NIGHT/...
Issued at 136 PM MST Sat Nov 22 2025

This morning`s patchy dense fog and low stratus continues to slowly
erode from the south and you can find some sunshine at times. Those
of us who make it out from underneath the stratus blanket will warm
into the upper 40s to even near 50 degrees, and the rest will remain
in the low to mid 40s. Look for more of the same tonight as some
patchy dense fog and low stratus keep hanging around until we can
get Monday`s cold front to blow it out of here. Any patchy dense fog
tonight doesn`t look too widespread, so not anticipating another
Dense Fog Advisory at this time. Models are showing a thin band of
fog from Burley along the interstate up towards Pocatello and
Blackfoot where we are seeing some of the most clearing, along with
some fog out across the Arco desert. The HREF gives it about a 30 to
40 percent chance of visibility dropping below a half mile at times
tonight within that band of fog, but that seems heavily weighted by
the HRRR while the NAM shows visibility closer to 1 to 2 miles and
the NBM only gives a 10 percent chance of visibility blow a mile.
There`s about a 20 percent chance for fog to work its way into Idaho
Falls, too. So still expect to drive into some patches of dense fog
early Sunday morning if you are out and about and be alert and
cautious. Sunday afternoon will be nearly a repeat of today. Late
Sunday night our next cold front will begin to move into the area.
More on that below...

&&

.LONG TERM /MONDAY THROUGH SATURDAY/...
Issued at 136 PM MST Sat Nov 22 2025

Fast moving shortwave drives across Idaho with cold front passage
during the day Monday. Impacts are still expected to remain minor
with light precipitation and snow accumulation focused mainly over
the higher terrain. Winds increase along and behind the front, with
speeds still expected to reach 25-30 mph and gusts around/over 40
mph especially across the Upper Snake Plain. There is still
uncertainty headed into the Thanksgiving holiday travel period, as
the ensemble clusters show signs of the next intermountain ridge
breaking down by Thanksgiving. By Friday, half of the clusters
depict a trough shifting into the western states while the other
half maintain a ridge over the coastal states or intermountain west.
 Either way, they all show some sort of a trough across or already
through the western states by the weekend, with nearly half of the
clusters depicting a deep trough similar to the operational GFS. It
is also fair to note that the slower or less amplified clusters
appear to favor the EC ensembles. The pattern stays somewhat
unsettled and trending colder into the weekend and early next week.
There is  potential for a much colder airmass early next week on the
periphery of the polar chill that may be headed for the north-
central states.

&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1032 PM MST Sat Nov 22 2025

We continue to monitor the potential for development of patchy fog
and low stratus overnight into Sunday morning. Earlier stratus that
lifted north of KIDA is showing some hints at filling back in down
across the Arco Desert as (so far) stratus and not fog, while
moisture down to the south of the Snake Plain including the Bear
Lake area has manifested as fog. After reviewing the latest
guidance, have made only minor tweaks to the forecast and timing of
fog/mist potential at KBYI, KPIH, and KIDA, with confidence
remaining too low to introduce anything beyond MVFR conditions at
this time. Meanwhile, a brief period of low stratus at KDIJ is
breaking up, as confirmed by satellite trends, and guidance does not
believe it will return. Mostly clear skies are expected late morning
and afternoon Sunday, before high-level clouds start to move in from
the west in the evening ahead of our next approaching shortwave
trough that will cross the region Monday.

&&

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

&&

$$

SHORT TERM...AMM
LONG TERM...DMH
AVIATION...01