939
FXUS65 KBOI 162041
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
241 PM MDT Thu Oct 16 2025

.SHORT TERM...Tonight through Saturday night...A cool air mass
and lighter winds tonight will allow pockets of frost to develop
in the Upper Treasure Valley east of Boise and the Western Magic
Valley, so a Frost Advisory has been issued for these areas.
High clouds are expected to move overhead tonight which will
help prevent even colder temperatures, so lows in the Boise
Metro and Lower Treasure Valley should stay in the upper 30s to
around 40. A trough will move by to our north on Friday,
bringing another day of breezy winds and dry conditions. The
only chance for precipitation (10-20%) with this trough will be
in the West Central Mountains. High temperatures will increase
a few degrees from today, especially in southern areas, and will
be near normal. Pockets of frost are again expected Friday
night in the lower valleys. On Saturday, an upper level ridge
will briefly move overhead bringing lighter winds and mostly
sunny skies. Winds will start to increase Saturday night ahead
of the next system.

.LONG TERM...Sunday through Thursday...A broad trough will move
into the region Sunday through early Monday. Consensus has been
reached among all deterministic models, and show the trough is
not quite as amplified as previous runs, keeping most of the
moisture flow through Central and Southeast Idaho. This will
bring at least a 20% chance for precip across the area, but a
much better 70-90% chance of precip in eastern Oregon and west-
central Idaho mountains. With snow levels of 5-7 kft MSL during
the event most ridges will likely see 1 to 3 inches of snow,
with mixed precipitation in high elevation towns, with a lower
chance of snow accumulation. Lower elevations will see 0-0.1
inches of rain, with most locations only seeing brief light rain
or drizzle. As the trough moves in on Sunday, expect breezy
conditions with gusts up to 30 mph. Behind the trough on Monday,
temps will have dropped 5-10 degrees from Sunday, about 10
degree below normal. Flow through the week will be mostly zonal,
without a clear ridge or trough in place outside of a shortwave
Tuesday night. Temperatures will slowly rise back up to normal
by Wednesday. A stalled trough continually strengthens and
moistens off the coast by the end of the long-term, with models
disagreeing on when it makes landfall.

&&

.AVIATION...MVFR-LIFR in low stratus north and east of the
Magic Valley. Skies for the rest of the area are clear. Patchy
valley fog may redevelop tonight, though chances are low.
Surface winds: W-NW 5- 15 kt with gusts to 20-30 kt. Winds aloft
at 10kft MSL: N- NW 10-20 kt.

KBOI...VFR with mostly clear skies. Surface winds: W-NW 5-10
kt, with gusts 15-20 kt this afternoon.

Weekend Outlook...Mostly clear conditions Friday through
Saturday. Sunday clouds increase with widespread precip moving
in after Sun/10Z from NW to SE lasting through the day. Best
chance for precip is in the north. Snow levels during precip
drop from 9 kft MSL Sun morning to 6 kft MSL Sun evening. Winds
NW 5-15 kt Fri, S-SE 5-15 kt Sat, and SW-SE 5-15 kt with gusts
up to 25-30 kt Sun.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Frost Advisory from 3 AM to 9 AM MDT Friday IDZ014-016.
OR...None.

&&

$$

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SHORT TERM...ST
LONG TERM....JM
AVIATION.....JM