285
FXUS65 KBOI 040943
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
343 AM MDT Sat Oct 4 2025

.SHORT TERM...Today through Monday night...
Areas of precipitation associated with a shortwave trough
were observed this morning over south-central and southeast
Idaho, with the western Magic Valley along the edge of a
broader precipitation swath. Scattered showers are expected to
persist and develop later this morning across the western Magic
Valley into the Camas Prairie, diminishing by sunset. Breezy
winds are also expected through the Snake Plain this afternoon,
with gusts over 40 mph forecast to occur along the I-84 corridor
between Mountain Home and Twin Falls. Precipitation chances
of roughly 20-30% linger into Sunday across the central Idaho
Mountains and western Magic Valley, as a weak disturbance moves
southward out of western Canada. Snow levels fall to around 7000
feet on Sunday, which will lead to light snow accumulation in
the highest mountain peaks.

Additionally, the cooler fall air mass will remain in place
throughout the weekend. Drier low-level air will overspread most
of the region Sunday, and will promote colder overnight
temperatures, especially on Monday morning. Areas of frost are
likely in higher elevation valleys of eastern Oregon and
southwest Idaho as sub-freezing temperatures become more
widespread on Sunday and especially Monday morning.

.LONG TERM...Tuesday through Saturday...Brief shortwave ridging
Tuesday will quickly transition into southwesterly flow aloft
Wednesday. The feature of cause for this is a potent, positively
tilted upper-level trough extending off of Canada into the Pacific
Ocean, which will meander around the Pacific Northwest coast through
Friday. This will enable moisture transport into the region, as well
as aligning favorably against topography to introduce precipitation
chances beginning Thursday morning onwards. Chances will be highest
for higher elevations Thursday, however notable chances will begin
for lower elevations from Friday on. All of the long range models
have the upper-level trough/low move in retrograde, however they do
so in varying degrees. This, combined with the ECMWF having a
tropical systems remnant moisture be pulled all the way north into
the Great Basin, paint a picture of a wet end of week/weekend. The
extent of how much precipitation may fall is too uncertain at this
time. A gradual warming trend will be seen through the period, with
temperatures climbing from near normal to 5-10 degrees above normal.

&&

.AVIATION...Mostly VFR. Low cloud ceilings with periods of MVFR
conditions will continue across the Western Magic Valley until
afternoon. Few light showers continuing across SW Idaho currently,
with isolated to scattered heavier rounds expected for KTWF and KJER
after Sat/12z. Mtns obscured in low ceilings and precip. Snow levels
7k-8k ft MSL. Surface winds: W-NW 8-15 kt, with gusts to 20-25 kt
particularly in the Snake Plain. Then, W-NW/N 10-20 kt gusting up to
30 kt Saturday afternoon, with localized gusts up to 40 kt in the
Snake Plain. Winds aloft at 10 kft MSL: N-NW 15-25 kt.

KBOI...VFR. Mostly cloudy with a few low clouds. Foothills partially
obscured. Some indication of strong LLWS through Sat/16z, however
seems to be displaced west of KBOI. Surface winds: NW 9-15 kt with
gusts near 20 kts through morning. By afternoon, gusts may reach
near 30 kts.

Sunday Outlook...Patchy AM fog for sheltered mountain valleys and
basins. Isolated to scattered showers continuing over central Idaho
mountains. MVFR/IFR in heavier rain showers, IFR/LIFR in snow. Snow
levels 6k-7k ft MSL. Mountains obscured in precip. Surface winds: NW-
NE 5-12 kt. KTWF/KJER: SW-NW 5-12 kt.&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.

&&

$$

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SHORT TERM...JR
LONG TERM....CH
AVIATION.....CH