Appleton, Idaho Weather Forecast Discussion

945
FXUS65 KBOI 240819
AFDBOI
Area Forecast Discussion
National Weather Service Boise ID
219 AM MDT Wed Sep 24 2025
.SHORT TERM...Today through Friday night...High pressure aloft
will support temperatures about 10 degrees warmer than above 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 pulls a trough
axis down 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 also brings gusts up to 25 mph Friday morning through
afternoon, but otherwise conditions 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 longwave 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
longwave 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.
&&
.AVIATION...Skies clear and VFR. Surface winds: variable up to
10 kt. Winds aloft at 10kft MSL: S-SE 5-10 kt.
KBOI...Skies clear and VFR. Surface winds: SE 5-10 kt, becoming S-SE
after sunrise.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.
&&
$$
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SHORT TERM...JM
LONG TERM....JM
AVIATION.....JM

NWS BOI Office Area Forecast Discussion