461
FXUS65 KBOI 160237
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
837 PM MDT Wed Oct 15 2025

.DISCUSSION...Back edge of rain has held nearly stationary
since midday, extending through Yellowstone-Sun Valley-Gooding-
Elko/NV. Hi-res models take it slowly eastward overnight, rain
finally ending in Twin Falls County around sunrise. Clouds and
west/northwest winds should keep temps warm enough to prevent
frost in the ID ag valleys overnight, but early Friday morning
looks clear, calm, and cold enough (36F or below) for patchy
frost. Meanwhile, eastern OR looks clear and cold tonight with
lows in the 20s to lower 30s. A weak short wave trough will
bring clouds into eastern OR from the northwest Thursday night
and Friday. Otherwise, mostly clear, breezy, and warmer in our
CWA through Saturday. Strong cold front will arrive Sunday
(see long term, below for details). No updates for now.

&&

.AVIATION...MVFR-LIFR in precipitation and low stratus in
S-central ID (KTWF/KJER). Precipitation will persist in
S-central ID until 12z/Thu. Mountains obscured in precipitation
and low ceilings. Snow levels dropping to 5-6.5 kft MSL
overnight Wednesday into Thursday. Surface winds: W-NW 5-15
kt with gusts 20-30 kt through the Snake Plain. Winds aloft
at 10kft MSL: N-NW 10-20 kt.

KBOI...VFR. Surface winds: W-NW 5-10 kt, with gusts 15-20 kt
beginning early Thursday morning.

&&

.PREV DISCUSSION...
SHORT TERM...Tonight through Friday night...An upper low to our
south will move east across Utah tonight. Rain showers will
decrease from west to east tonight as the low pulls away, ending
late tonight in the Magic Valley. Winds will be breezy tonight
into Thursday as the surface pressure gradient strengthens
behind the low. Increased winds should help prevent agricultural
valley temperatures from dipping much below 40 degrees tonight.
Temperatures on Thursday will remain around 5 degrees below
normal under dry northwest flow aloft. Afternoon wind gusts of
20 to 35 mph will be common across the Snake Basin, strongest
east of Boise. On Friday, northwest flow aloft will continue as
a shortwave trough moves by to the north, which will keep winds
breezy. Temperatures will warm a few degrees, but remain a
couple degrees below normal. Overnight lows will be similar
Thursday and Friday nights, but lighter winds may allow
sheltered areas in the agricultural valleys to dip into the mid
30s, with around a 30% chance of lows 36 degrees (frost threshold)
or colder.

LONG TERM...Saturday through Wednesday...Saturday will be mostly
clear, dry, with seasonal temps moderated by northwesterly flow
under a low-amplitude ridge ahead of a rapidly amplifying trough
along the Canadian west coast. Clouds increase Saturday night and
Sunday morning as the trough approaches, with the first round of
precipitation set to arrive Sunday around noon in eastern Oregon.
The GFS and EC deterministic and ensemble members are in broad
agreement, with the added addition of the EC/EAGLE AI models
agreeing. Precipitation will arrive in ID Sunday evening, with
orography supporting moderate rain/snowfall over the mountains.
Precipitation chances in E Oregon and W-central Idaho mountains is
60-80%, with a couple of inches of snow along summits thanks to
~5 kft MSL snow levels. Winds pick up and temperatures drop to
10 degrees below normal on Monday. Monday through Wednesday
broad ridging returns to the area with northwesterly flow,
leading to a slow but steady warming trend and scattered clouds.
The Canadian model remains out of line with the synoptic forecast
of the GFS/EC/EAGLE, so while some uncertainty remains it seems
like a clear-cut outlier now.

&&

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

&&

$$

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DISCUSSION...LC
AVIATION.....CH
SHORT TERM...ST
LONG TERM....JM