663
FXUS65 KPIH 131752
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1052 AM MST Thu Nov 13 2025

.KEY MESSAGES...

- Well above normal temperatures continue through today.

- Dry conditions continue through most of Thursday. Light
  precipitation starts Friday for northern areas. More wide-
  spread precipitation Sunday into Monday.

- Cooler temperatures return into the weekend and especially
  early next week.

&&

.SHORT TERM /THROUGH FRIDAY/...
Issued at 112 AM MST Thu Nov 13 2025

Looking at the current water vapor imagery there is a high
pressure ridge axis over eastern Idaho with a deep upper-level
trough off the Pacific coast with an upper level low off the
California coast as a part of this trough. Models show this
ridge moving east of the area by this afternoon allowing for
southerly flow across southeast Idaho this afternoon. Clouds
will become mostly clear to partly cloudy instead of mostly
cloudy due to a dry slot in the upper level flow.

The deep upper-level trough off the Pacific coast splits with
the upper level low off the California coast dipping south and a
weak trough/cold front moving over Washington, Oregon, and
Idaho. This trough/cold front skirts mainly our northern areas
on Friday bringing very light high mountain snow and very light
valley rain. Precipitation amounts have backed off significantly
with this trough/cold front Friday. Expect up to around 0.10
inch of precipitation for our northern areas (Central Mountains
and the Montana Divide). Only around 1 inch of snow is now
expected above 8000 to 9000 feet in the Central mountains.
Temperatures will still be above normal (10 to 15 degrees) today
with temperatures of mid to upper 50s and mid 60s expected.
Temperatures drop slightly now Friday. Temperatures look to
still be above normal Friday with temperatures of upper 40s and
upper 50s with a few lower 60s expected. &&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 122 PM MST Wed Nov 12 2025

Fri through next Wed night. The current weak Rex block continues
into Sat, but an upper level trough breaks up the weak ridging
and comes in phase with the closed low over southern CA and it
appears to merge and bring the moisture of the closed low from
CA into the Pac NW on Mon, then most solutions bring an open
wave through the northern Rockies on Tue, with 32 percent of the
solutions keeping the moisture farther south, so it is not a
slam-dunk at this time, but it looks very good for some much
needed "catch-up" precipitation for November. Light
precipitation could start as early as Sun in the mountains. The
upper level troughing stays around through Wed night with more
troughing in 65 percent of the solutions in the clusters.

After the first merging upper level trough, which will likely
have mild temperatures, the others later in the week appear to
have much colder air, bringing temperatures down from 15 to 20
deg F above normal for afternoon highs to 5 to 10 deg F above
normal on Mon. With the abundant cloud cover at night, overnight
lows continue mild for the time of year, even in the Stanley
Basin.

Expect a tremendous change in the wind, which lately has been so
close to calm, to be breezy to windy (10 to 20 mph Fri, then Sun
afternoon onward 15 to 25 mph with higher gusts).

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Issued at 122 PM MST Wed Nov 12 2025

Fri through next Wed night. The current weak Rex block continues
into Sat, but an upper level trough breaks up the weak ridging
and comes in phase with the closed low over southern CA and it
appears to merge and bring the moisture of the closed low from
CA into the Pac NW on Mon, then most solutions bring an open
wave through the northern Rockies on Tue, with 32 percent of the
solutions keeping the moisture farther south, so it is not a
slam-dunk at this time, but it looks very good for some much
needed "catch-up" precipitation for November. Light
precipitation could start as early as Sun in the mountains. The
upper level troughing stays around through Wed night with more
troughing in 65 percent of the solutions in the clusters.

After the first merging upper level trough, which will likely
have mild temperatures, the others later in the week appear to
have much colder air, bringing temperatures down from 15 to 20
deg F above normal for afternoon highs to 5 to 10 deg F above
normal on Mon. With the abundant cloud cover at night, overnight
lows continue mild for the time of year, even in the Stanley
Basin.

Expect a tremendous change in the wind, which lately has been so
close to calm, to be breezy to windy (10 to 20 mph Fri, then Sun
afternoon onward 15 to 25 mph with higher gusts).

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1052 AM MST Thu Nov 13 2025

Mid and high level moisture is beginning to stream into Idaho
ahead of amplified split trough system moving toward the region.
Skies remain VFR throughout the forecast period, but we begin to
see showers shift into East Idaho overnight through the day
Friday, starting at SUN after 09Z and DIJ after 14Z. Confidence
is lowest for the Snake Plain terminals BYI, PIH, and IDA, but
introduced VCSH after 12Z for each of those sites. Winds
increase slightly overnight, and should be strongest Fri after
18Z behind the cold front.

&&

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

&&

$$

SHORT TERM...TW
LONG TERM...Messick
AVIATION...DMH