Vale, Oregon Weather Forecast Discussion

389
FXUS65 KBOI 241546
AFDBOI
Area Forecast Discussion
National Weather Service Boise ID
946 AM MDT Wed Sep 24 2025
.DISCUSSION...No updates. Warm and dry through Thursday with
upper level high pressure directly overhead. Dry cold front
Friday will bring 6-12 degrees cooling along with breezy west/
northwest winds. Warm and dry again Saturday and most of Sunday.
Slight chance of showers along the ID/NV border late Sunday.
The big change will come Monday when a strong Pacific surface
cold front and supporting upper trough come in. The front will
introduce gusty west winds, cooler temps, and showers. Current
PoPs are conservative due to uncertainty 5 days out, but will
increase as the event draws nearer.
&&
.AVIATION...VFR with clear skies. Surface winds: E-SE 5-15 kt.
Winds aloft at 10kft MSL: E-SE 5-10 kt.
KBOI...VFR with clear skies. Surface winds: SE 5-10 kt this
morning, becoming SW up to 10 kt this afternoon.
&&
.PREV DISCUSSION...
SHORT TERM...Today through Friday night...High pressure aloft will
support temperatures about 10 degrees warmer than normal through
Thursday with fairly light winds, clear skies, and dry conditions.
Late Thursday through Friday morning a dry cold front will move
through the area as a stalled upper low in Calif helps pull a
trough axis southward over the Pacific Northwest. This will
drop temperatures to 5 degrees warmer than normal with high
temps in the high 70s for lower elevations and in the high 60s
for higher elevations. The front will also bring gusts up to 25
mph Friday morning through afternoon, but otherwise conditions
will remain dry with brief increased cloud cover before the
front. Some smoke from nearby fires may create hazy surface
conditions, mainly in west-central Idaho.
LONG TERM...Saturday through Wednesday...The closed low moves
back down over southern California, allowing high pressure to
briefly build back in and warm temperatures by a few degrees back
to the 5-10 degree above normal range. However, as the closed
low begins to move eastward out of the area, it makes way for a
much beefier long wave trough that moves into the area Sunday.
Moisture from the closed low flows into the east side of the
long wave trough, allowing precipitation to begin Sunday evening
ahead of the trough axis and front. This early moisture is
favored to flow mostly through Idaho among ensemble means, the
chance of precipitation Sunday evening is 15-25%, with a similar
chance for thunder. As the long wave trough continues to move
into the area, precipitation chances rise to 30-50% every 6
hours through early Wednesday, with convection and thunder
possible each afternoon. The colder airmass behind the frontal
system of the trough cools temps to near normal on Monday and a
few degrees below normal Tuesday and Wednesday. Wind gusts up to
25 mph are also possible each day. Wednesday there is
disagreement among deterministic models, but generally as the
trough axis moves east, another low begins to develop in the
Gulf of Alaska. A moister surface and possible brief clearing
and light winds Wednesday morning supports the potential for
fog development.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.
&&
$$
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DISCUSSION...LC
AVIATION.....JY
SHORT TERM...JM
LONG TERM....JM

NWS BOI Office Area Forecast Discussion