810
FXUS65 KBOI 271003
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
303 AM MST Thu Nov 27 2025

.SHORT TERM...Today through Saturday night...Light warm-frontal
pcpn has shifted east of our CWA. leaving areas of fog, locally
dense, in the valleys this morning. At the time of this writing
we are on the verge of issuing a Dense Fog Advisory for the
Lower Treasure Valley east to Boise through the morning hours.
Otherwise, our CWA will be in the warm-sector between the
exiting warm front and the next cold front due to arrive Friday.
Early this morning the cold front was just off the northwest
coast with a supporting upper level trough near 140W. These will
move inland tonight, and through our CWA Friday. Until then our
area will be partly cloudy, dry, and mild. The cold front will
bring a brief period of rain and snow to Baker County Friday
morning, then hit our Idaho zones a little harder later Friday,
generally north of the Snake Basin. Gusty northwest winds 20-30
mph will follow the front Friday afternoon, strongest in the
Western Magic Valley. Clearing, calming, and colder Friday
night, especially at higher elevations. Northwest flow aloft
Saturday will bring another short wave trough from BC into our
CWA Saturday night, and it is that trough that may bring the
first light snowfall of the season to the lower southern valleys
including the Treasure Valley and western Magic Valley. GFS, in
particular, looks cold and moist enough for snow, while other
models also have that signal, but weaker for now.

.LONG TERM...Sunday through Thursday...Early Sunday will
see the back end of a shortwave trough exit the area as a
large ridge builds into the Northwest region through most of
Monday, bringing dry conditions. Valley daytime temperatures
are expected to remain in the lower to mid 40s Sunday through
Monday, and snow levels in the 2000-3000 ft range. Late Monday
through Wednesday will see a longwave trough digging into the
region, though with uncertainty over the arrival and depth of
this trough. For now, precipitation is generally expected
Tuesday through early Wednesday. Lower elevation daytime
temperatures are expected to remain in the lower to mid 40s
throughout the extended period, and snow levels in the
3000-4000 ft range. Late Wednesday and early Thursday will
tentatively see a brief elongated ridge pattern extend into
the area, returning drier conditions.

&&

.AVIATION...Areas of MVFR/IFR ceilings over E-Central OR (KBKE)
and Upper Treasure Valley overnight and Thursday morning.
Patchy IFR/LIFR fog in sheltered valleys and mountains continuing
overnight through Thursday afternoon. Surface winds: variable
under 8 kt, becoming E-SE 5-15 kt across the Snake River plain
Thursday afternoon. Winds aloft at 10kft MSL: W 20-30 kt.

KBOI...IFR/LIFR ceilings over terminal Thursday early morning.
Intermittent IFR/LIFR fog may engulf terminal until Thursday
late morning/early afternoon. Surface winds: light and variable
overnight, becoming E-SE 5-10 kt Thursday morning/early
afternoon.

Weekend Outlook...A cold front will return precipitation late
Saturday through early Sunday, with snowfall likely in the
mountains and light rain and/or snow in the lower elevations.
Snow levels in the 2000-3000 ft range Saturday and Sunday.
Patchy fog expected during overnight/early morning hours on
both days. Winds E-SE 5-10 kt Saturday becoming W-NW 5-10 kt
Sunday, with afternoon gusts 15-20 kt near KMUO.

&&

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

&&

$$

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SHORT TERM...LC
LONG TERM....JY
AVIATION.....JY