914
FXUS65 KPIH 230527
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1027 PM MST Thu Jan 22 2026

.KEY MESSAGES...

- Fog and low clouds will continue to affect some areas through
  Friday, especially during the overnight and morning periods,
  amid a continued quiet weather pattern for the region.

- A pattern shift is possible into the weekend with a trough
  moving through tomorrow which could clear out the daily fog
  and stratus. There remains uncertainty with this though.

- Continued dry into next week with a warming trend likely
  although valley inversions could wreck havoc with this.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 109 PM MST Thu Jan 22 2026

Afternoon satellite imagery shows widespread lower valley
stratus back again after about a 6-12 hour reprieve.
Temperatures have been slow to rise accordingly, yet again,
and continued to significantly lower afternoon high temp
forecasts and raise overnight lows accordingly. Based off the
lack of any noticeable degradation of the cloud deck, seems
unlikely that it`ll erode this evening so it`ll likely continue
at least until the late morning on Friday. Outside of the lower
valleys, sunshine remains in place with just some occasional
mid-high level clouds. Tomorrow, upper level trough digs into
the region bringing a push of cooler air and maybe just enough
lift to support some low end PoPs across the higher terrain of
the eastern highlands but that will be about it on the precip
front. Winds will become more northerly during the day allowing
for colder air to filter in to eastern Idaho. It remains unclear
if this push will be enough to clear out the stratus from the
region. NBM says yes, the forecaster remains a bit skeptical
however. Hedged things and kept cloud cover in place into later
in the afternoon tomorrow before allowing things to clear out
into the overnight Friday and into Saturday morning. Model
soundings show the inversion lingering though so it`s possible
that this lower valley stratus sticks around into the weekend.
It`s really just a wait and see at this point with confidence
being quite low as models just don`t have a good handle on
things.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 109 PM MST Thu Jan 22 2026

Weekend forecast remains highly dependent on the overall
progression of the aforementioned inversions. Model guidance
suggest a seasonably cool weekend with the region seeing a
couple of cooler than normal days followed by a warming trend
into next week as upper level ridging builds over the area once
again. Ridging will keep the area dry into the middle of next
week but the presence of continued inversions could make the
lower valley forecast challenging once again. If we avoid
stratus, we should warm nicely into the upper 30s to lower 40s
each day. If we don`t, much of next week could turn out to be
like much of this week. Confidence is low with regard to the
temps and stratus but high with regard to precip chances
remaining extremely low across eastern Idaho into the middle of
next week.

&&

.AVIATION /06Z TAFS THROUGH 06Z SATURDAY/...
Issued at 1022 PM MST Thu Jan 22 2026

Main impact remains presence of stratus and fog at all TAF
sites. PIH, BYI, SUN and IDA all have IFR ceilings and expect to
continue through tonight other than SUN where I think northwest
winds will dissipate stratus by 09Z. Dropped visibilities
somewhat at DIJ, PIH, IDA and BYI toward 12Z. Do think will see
clearing Friday afternoon of the stratus as back door cold front
moves through Idaho which should scour it out and dry things up
and to not expect a return to stratus Friday night and have
clear skies tomorrow evening. Winds stay light but should shift
to a northerly direction post cold frontal passage tomorrow
evening.

&&

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

&&

$$

SHORT TERM...McKaughan
LONG TERM...McKaughan
AVIATION...GK