353
FXUS65 KBOI 211224 CCA
AFDBOI

Area Forecast Discussion...CORRECTED
National Weather Service Boise ID
524 AM MST Sun Dec 21 2025

.SHORT TERM...Today through Tuesday night...The next system is
moving into the area this morning. Precipitation started off as
freezing rain at Burns OR but has quickly changed over to rain.
Snow levels will be at the surface in Baker County and near the
Weiser Basin and Ontario rising to around 7000-8000` from the
Snake Basin south. With accumulations up to 1-2 inches possible
along the I-84 corridor from Ontario to Baker City and from
Burns OR north. Mountain valleys and the Camas Prairie in ID
will see 2 to 4 inches of snow before changing over to rain
below 6000 feet. Moderate snow accumulations expected over the
mountains above 7000 feet, with 12 to 20 inches through Monday
evening. Precipitation amounts will be 1 to 2 inches over the
mountains with up to an inch in the valleys. Wind gusts of 40-50
mph expected south of a line from Steens Mountain to the
Owyhees and southern Twin Falls County. A wind advisory has been
issued for the southwest ID highlands. Precipitation becomes
showery in nature this evening, with showers focused mainly over
the mountains. Precipitation will briefly taper off on Monday
during the day as the stream of moisture moves south. Then it
will move northward late Monday evening into Tuesday with
another round of precipitation. Snow levels Tuesday will be
around 6000-7000` with the band of precipitation. Precipitation
amounts on Tuesday will be around 0.5 inch over the central ID
mountains with lesser amounts in the valleys.

.LONG TERM...Wednesday through Sunday...Continuous Pacific
moisture flux due to a broad upper troughing pattern off the
PacNW coast will drive a continuous active and warm pattern
through the long term. Precipitation chances Wednesday through
Friday are around 30-70%, lower in valleys and higher in
mountains. Snow levels start generally high at 6-7 kft MSL,
though slowly decrease down to 4-5 kft MSL by Saturday. This
late week period will see 3-8 inches of snow in mountains above
5 kft MSL, up to 10 inches above 7 kft MSL. Most valleys get
around 0.1" of rain, translating to 0.5-1" of rainfall/liquid
equivalent for the mountains. The temperatures warm to about
10-15 degrees above normal, highest Wednesday, so snow in
mountain towns may be preceded by rain and become a wet slushy
snow when it begins to fall. Models show a slightly drier
pattern Saturday and Sunday but keep a 15-25% chance of
precipitation as temps drop to 5 degrees above normal with snow
levels at 3.5-4.5 kft MSL. Ridgetops remain gusty through the
long term, up to 30 mph each afternoon.

&&

.AVIATION...VFR conditions becoming MVFR-LIFR as rain and snow
moves into the region. Precipitation is increasing this
morning with rain below 3-5 kft MSL and snow above, snow levels
increasing to 6-7 kft MSL this afternoon. Freezing rains is
possible near KBKE, KBNO, and KONO this morning through about
Sun/16Z.Precip continues through the day, becoming more tied to
terrain Sunday night. Surface winds: SE-SW 5-15 kt with occasional
gusts to 25 kt, except SW 20-30 kt southwest of the Snake River
Valley. Winds aloft at 10kft MSL: W-SW 40-70kt.

KBOI...VFR early this morning, with a 50% chance of MVFR-IFR
ceilings as rain begins to move in. Rain could be moderate at times.
Coverage decreases late this afternoon/evening, but continues in the
foothills. Surface winds remain SE 5-15 kt.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory from 11 AM this morning to 5 PM MST this
     afternoon IDZ015.
OR...None.

&&

$$

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SHORT TERM...KA
LONG TERM....JM
AVIATION.....JM