Nampa, Idaho 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

420
FXUS65 KBOI 022107
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
207 PM MST Mon Feb 2 2026

.SHORT TERM...Tonight through Wednesday night...
Upper ridging building into the area will continue to promote
stagnant, inversion conditions over the region. This also means
dry air with generally light winds, and no sign of precipitation
beyond this evening after a weak system ejects eastward. A
near-persistence forecast is in store, with high temperatures
peaking in the low 50s each day across lower elevation valleys,
and falling to near or below the freezing mark each morning.
Patchy fog is also possible each morning, especially in the
lower Treasure Valley and central Idaho mountain valleys. The
strength of the ridge will only increase into Wednesday, with
model guidance suggesting 582-585 dm 500 mb heights - close to a
record for the date per the SPC sounding climatology.

.LONG TERM...Thursday through Monday... High pressure is the name of
the game through the end of this week. As has seemed to be the
pattern of choice so far this winter, an amplifying ridge over our
area and a deepening closed low near the Baja Peninsula will make
way for a rex block. This will keep the day to day forecast very
similar to each other with valley inversions and stagnant
conditions. Valley fog/low stratus will be the the only hazard
through the coming week. While temperatures will be above normal
area-wide, valley cold pools will help limit lower elevation daytime
highs each day. Through sunday, the current forecast carries daytime
highs below the NBM 25th percentile.

The door will start to open for a more unsettled pattern late this
week as the closed low near the Baja Peninsula begins to re-embed
into the main flow aloft. At the same time, the trough that has been
over the Hudson Bay will begin to propagate east. Deterministic and
model ensembles are in good agreement of a longwave trough moving
over the western CONUS late this week/early next week. This trough
will usher in cooler temperatures increased precipitation chances,
and will break up the inversion.

&&

.AVIATION...VFR this afternoon/evening. Patchy freezing fog/low
stratus returning overnight in sheltered mtn valleys and in the
lower Treasure Valley. MVFR/LIFR and mtn obscuration in fog/low
stratus. Surface winds: Variable up to 10 kt. Winds aloft at 10kft
MSL: W-NW 10-20 kt.

KBOI...VFR with some high clouds this afternoon/evening. A lower
stratus deck may develop overnight, but conditions remain VFR.
Surface winds: Light and variable, leaning SE after Tue/03z.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Air Stagnation Advisory until 11 AM MST Friday
     IDZ012-014-016-033.
OR...Air Stagnation Advisory until 11 AM MST /10 AM PST/ Friday
     ORZ064.

&&

$$

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SHORT TERM...JR
LONG TERM....NF
AVIATION.....NF