116
FXUS65 KBOI 140926
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
326 AM MDT Tue Oct 14 2025

.SHORT TERM...Today through Thursday night...A closed low
centered just off the San Francisco coast this morning is
already spreading showers and a few thunderstorms north across
southwest Idaho. A jet streak moving across Nevada and Utah are
helping to spark this initial activity, which is focused along
the Nevada/Idaho border this morning. A slight chance (15
percent) for this activity to push further north into the
southern Boise Mountains later this morning as showers gradually
continue moving north northwest. As the low shifts inland
across California later today, a shift to warmer southerly winds
will slightly increase temperatures and provide a 10 to 20
percent chance of afternoon thunderstorms, primarily over the
highest terrain in Central Idaho. Rainfall will be minimal
through this evening, generally less than 0.10 inches, with snow
anticipated only on the highest peaks above 7000 feet.

A more organized push of moisture will arrive late tonight into
Wednesday morning as the storm center moves north and east
across Nevada and into Utah. This will set up a band of heavier
precipitation across mainly southwest Idaho. Current high res
model guidance shows the heaviest rain remaining south of the
Rome-Boise-Stanley line. Rainfall totals from this band will be
around 0.20 to 0.50 inches by Wednesday night, with noticeably
cooler temperatures. Snow levels will drop to 6500 to 7500 feet
by Wednesday evening, bringing another 1 to 3 inches of snow to
mountain ridgetops in the heaviest showers. The Boise area
remains on the northern edge of the heaviest precipitation, with
only a 30 percent chance of seeing greater than a tenth of an
inch of rain.

Cooler northerly flow will settle in behind the exiting low
pressure system on Thursday. This will result in mostly dry
conditions and keep temperatures about 5 degrees below normal.

.LONG TERM...Friday through Tuesday...As an upper-level low
pressure system departs to the east, high pressure building over
the northern Pacific will establish a general northwesterly
flow across the region. From Friday through early Sunday, this
pattern will bring enough moisture for persistent scattered
clouds, but with limited instability, precipitation chances will
remain below 10%. Temperatures are expected to be near seasonal
normals.

Significant uncertainty arises in the forecast from Sunday
onward, concerning a deep trough approaching the coast. The
current forecast maintains a 40-50% chance for precipitation,
with snow levels falling to near 5,000 feet MSL and temperatures
dropping as much as 10 degrees below normal. However, confidence
in this scenario is decreasing. Recent ensemble guidance and a
few deterministic models are now showing a weaker trough, with
some solutions keeping it from impacting the region
entirely.Given the model disagreement, the forecast will
maintain chances for a wetter and colder solution for now, but
significant changes are possible in the coming days.

&&

.AVIATION...Mostly VFR overnight, with local mtn obscuration from
low-VFR ceilings. Scattered showers early Tuesday morning will bring
low-VFR and local MVFR ceilings and mtn obscurations. Snow levels
rising to between 7500-8500 feet MSL. Surface winds: variable or W-
NW 5-15 kt. Winds aloft at 10kft MSL: variable 5-15 kt.

KBOI...VFR. Rain showers possible this morning after 10Z. Surface
winds: NW 5-10 kt, then light and variable after 12Z.

&&

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

&&

$$

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SHORT TERM...JDS
LONG TERM....JDS
AVIATION.....JY