899
FXUS65 KPIH 272334
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
434 PM MST Thu Nov 27 2025

.KEY MESSAGES...

- Occasional mainly mountain rain and snow showers continue.

- Above average temperatures through Friday.

- Cold unsettled conditions continue throughout the extended,
  with potential for light snow accumulations down to valley
  floors at times.

&&

.SHORT TERM /THROUGH FRIDAY NIGHT/...
Issued at 128 PM MST Thu Nov 27 2025

Quiet weather and mostly mild temperatures in place across much
of eastern Idaho on this Thanksgiving afternoon. Afternoon
satellite imagery shows cloud cover gradually on the increase
however, especially in SW Idaho, and this cloud cover will make
its way back into our area overnight and into Friday morning.
Until then however, temps are quite mild for late November with
upper 40s to mid 50s in place across the lower valleys this
afternoon. Today will be the warmest day though over the next
week as things take a downward trend beginning tomorrow. Dry
conditions will continue across the area until tomorrow. That`s
when an upper level shortwave will swing through the region
bringing with it increased cloud cover and precipitation chances
once again. Looks like precip will mostly be limited to the
higher terrain of the central mountains, along the Montana
Divide and into the eastern highlands. Cooler temps tomorrow
will support snow as the dominant precip type in these areas but
this system won`t have much moisture with it so with QPF
generally around a tenth or less, snowfall amounts are likely to
be an inch or less for most areas that do see precip. Some
higher mountains passes and peaks could get a touch more. Not
expecting much, if any, precip to fall in the lower valleys
tomorrow although a stray shower or two is certainly possible.
Temps in the Snake Plain would likely support more of a
rain/snow mix, especially if during the afternoon hours. Either
way though, not expecting anything overly impactful if/when
precip does occur in our valley areas. Temps Friday will be
about 5-10 cooler than today with them continuing to trend down
as we move into the weekend. More on that below.

&&

.LONG TERM /SATURDAY THROUGH THURSDAY/...
Issued at 128 PM MST Thu Nov 27 2025

Series of shortwaves expected to impact East Idaho through the
extended, increasing deep and cool northerly flow and
introducing the potential for light snow even to lower
elevations. The first shortwave arrives Sat into Sunday, but a
lack of significant moisture will keep precipitation amounts
light with minimal, if any, travel impacts. The highest snowfall
amounts look to be Sunday into Sunday night with generally 1-3"
across higher elevations in the southern and southeast
highlands. Cooler air mass is in place for Sunday into Monday,
with daytime highs in the 30s and overnight lows in the teens.
Once again the deterministic NBM temps are outliers to the
spreads, so could see some changes in forecast temperatures
moving into the weekend. Following a break in the precipitation
Monday, next shortwave drops into the region Tuesday.
Differences in the ensemble clusters are starting to become more
amplified this far out, leading to differences in precipitation
potential for East Idaho. Temperatures still look cold enough
to sustain snow or brief mix in the afternoon with potential for
light accumulations even to valley floors. Looking ahead to the
latter half of the week, ensembles diverge significantly, with
a roughly 60/40 split between rebuilding a ridge across the west
or introducing a faster system to the PacNW. There is little
certainty by the time we reach the end of the forecast period.

&&

.AVIATION /00Z TAFS THROUGH 00Z SATURDAY/...
Issued at 434 PM MST Thu Nov 27 2025

Generally low-impact VFR conditions will continue through late
Friday morning. Starting midday, winds will increase out of the WSW,
especially at KBYI and KPIH, along with some increased cloud cover
as our next shortwave trough crosses the region. A shift from SE to
WSW winds is expected during the afternoon at KSUN as advertised in
the TAF. CAMs are fairly "light, spotty, and messy" with regard to
supporting rain/snow shower activity with this shortwave, and so far
we only have confidence to go with VCSH at KDIJ (after 19z/noon)
with better chances elsewhere confined to mountain ranges. However,
there is potential for a brief period of more impactful snow toward
the end of the TAF period Friday eve at KDIJ, likely after 23z/4pm,
which could feature MVFR cigs and IFR vsbys. If model guidance
remains consistent in this scenario, these impacts may appear in the
next TAF update issued this evening.

&&

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

&&

$$

SHORT TERM...McKaughan
LONG TERM...DMH
AVIATION...01