320
FXUS65 KPIH 011718
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
1118 AM MDT Wed Oct 1 2025

...UPDATED AVIATION...

.KEY MESSAGES...

- Showers and storm will persist, but less numerous through
  Thursday

- Temperatures briefly warm up

- Showers, storms and much colder temperatures heading into the
  weekend

&&

.SHORT TERM /THROUGH THURSDAY NIGHT/...
Issued at 1215 AM MDT Wed Oct 1 2025

Unsettled weather is expected to continue over the next couple days.
We`re in southwest flow ahead of deep upper level trough. Isolated
to scattered showers and thunderstorms will move through our region
in this flow. Although we`re not looking at anything organized. As
we move into Thursday and especially Thursday night a cold front and
associated low pressure system will approach the region from the
west-southwest. Ahead of this system during the day on Thursday, the
central mountains will see numerous showers throughout the day. The
rainfall will become heavier Thursday Night as the low pressure
system and cold front move into southwest Idaho. During the day on
Thursday the rainfall will still likely be light with amounts
expected to be between 0.10 to 0.25 inches in the central mountains.
Across the rest of central and east Idaho, activity will remain
isolated to scattered with amounts expected to be less than 0.10
inches. As we move into Thursday Night, rainfall amounts in the
central mountains could exceed 0.50 inches perhaps approaching 1
inch, perhaps resulting in issues for the Wapiti burn scar. For the
rest of central and east Idaho, latest guidance indicates the cold
front will not arrive until Friday so rainfall amounts Thursday
night for central and east Idaho will most likely be light and less
than 0.10 inches.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
Issued at 1247 PM MDT Tue Sep 30 2025

The next big chance of precipitation and thunderstorms is
Thursday night through Saturday evening. With split flow
continuing over the western states, the next storm will be
undergoing this change as it moves inland. The current trends
will initially take the closed low/southern end of the split to
our southwest, and then swing it northeast across Utah and
western Wyoming going into Saturday. The current pattern shows
Thursday night into Friday with a band of heavier precipitation
across portions of the Magic Valley and central mountains, not
that different that what occurred last night. That band stays in
place, and eventually shifts when the storm crosses through and
east of the Divide. If current trends hold, this is a pattern
for heavier precipitation due to wraparound and upslope along
and east of the I-15 corridor. There is a MARGINAL RISK for
excessive rainfall Thursday night across the central mountains.
While it is certainly possible we could see some debris flow
issues, the risk is lower at the moment. With a colder system
moving in, that does mean some wet, slushy snow is possible on
higher peaks and ridges. Forecast snow levels are currently
getting down to around 8000-8500ft in the central mountains and
~9000ft across the southeast highlands. If we can maintain
heavier amounts or end up with colder temperatures, there is
potential for snow levels to PERHAPS drop between 6500-8000ft
areawide...according to the Blend of Models snow level
forecasts. That doesn`t necessarily we would see a bunch of
accumulation at those elevations, but we could easily snowflakes
in the sky and melting as they hit the ground. Right on the
heels of this low, another drops down into the western U.S., and
does a similar thing with another split flow system developing.
Even if we see less precipitation with that one, it will
maintain cooler temperatures across the state. Highs over the
weekend based on the current Blend of Models forecast barely
touch 60 degrees in the valleys with 30s and 40s for anyone
wanting to take a trip to the high country!

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 1115 AM MDT Wed Oct 1 2025

We will see showers and a few storms around through tomorrow.
Unless a stronger shower or storm pops up directly over any
particular TAF site, look for VFR weather. The only airport we
have VCSH in for is SUN and that has been continued from the
previous set of forecasts. Due to limited coverage, we removed
any mention for other TAFs. Right now, coverage and/or
confidence is too low to even include PROB30.

&&

.FIRE WEATHER...
Issued at 1215 AM MDT Wed Oct 1 2025

Unsettled weather will continue through Thursday
with isolated to scattered showers and thunderstorms. Rainfall
amounts expected to be light, less than 0.10 inches. A few wind
gusts of 15 to 20 mph will remain possible each afternoon. A more
organized system will arrive Thursday night and Friday resulting in
better chances for wetting rains.

&&

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

&&

$$

SHORT TERM...13
LONG TERM...Keyes
AVIATION...Keyes
FIRE WEATHER...13