857
FXUS65 KPIH 301917
AFDPIH

Area Forecast Discussion
National Weather Service Pocatello ID
117 PM MDT Tue Sep 30 2025

.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 WEDNESDAY NIGHT/...
Issued at 1247 PM MDT Tue Sep 30 2025

We are still expecting multiple rounds of rain and
thunderstorms through tomorrow night. Coverage and precipitation
amounts will be less than what we saw last night and this
morning, but some places could still see locally moderate/heavy
hourly rates. There is a MARGINAL RISK for excessive rainfall
over eastern areas today, but any real threat is VERY LOW at the
moment. It is something to monitor though especially over any
recent burn areas. There is a 10-30% chance of outflow gusts in
the 35-45 mph range still through this evening.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
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 WEDNESDAY/...
Issued at 1115 AM MDT Tue Sep 30 2025

Main impact will be some early afternoon showers at PIH and
showers will linger at DIJ most of the night. Have prob 30
thunder at all sites after 21Z today as well. Generally dry
overnight with the exception of DIJ but all locations expected
to be dry Wednesday morning. MVFR ceilings expected to lift at
SUN this afternoon by 20Z.

&&

.FIRE WEATHER...
Issued at 1247 PM MDT Tue Sep 30 2025

Showers pushing east with most overnight in zones 411 and 413 where
still a threat for wetting rain.  Mainly isolated showers on
Wednesday also mostly zones 411 and 413 as well as 422.  Will see
more widespread showers Thursday through Saturday with wetting rains
possible again especially in higher elevations.  Near normal
temperatures Wednesday and Thursday then significant cool down
commences Friday with well below normal temperatures through Monday.
Sunday through Tuesday is trending drier with only isolated
showers. Not expecting significant winds through the week.

&&

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

&&

$$

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