335
FXUS65 KBOI 041003
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
403 AM MDT Thu Sep 4 2025

.SHORT TERM...Today through Saturday night...Upper level ridge
continues to weaken over the short term with a gradual cooling
trend. Isolated showers and thunderstorms this afternoon, mainly
near the NV border and central ID mountains. Showers and storms
are capable of producing outflow winds up to 40 mph this
afternoon and again on Friday afternoon. An upper level trough
will approach the region from the west, with scattered showers
and isolated thunderstorms on Friday afternoon. The through will
remain off the northern CA coast on Saturday as a shortwave
moves inland. Precipitable water values reach the 80-85th
percentile on Saturday, or around 0.75 inch. The dynamics of
this trough will interact with the mid level moisture already in
place, with a 20-30 percent chance of thunderstorms across
eastern OR and far southwest ID, and a 10-20 percent chance of
thunderstorms north and east of the Snake Plain. Temperatures
cool to near normal by Saturday.

.LONG TERM...Sunday through Thursday...The upper level trough
slowly moves inland on Sunday and elongates over the Pacific NW
to northern CA. Strong southwest flow aloft arrives with a dry
slot developing over the area, with breezy west-southwest winds
during the afternoon. This will keep showers and thunderstorms
confined to the central ID mountains through Tuesday.
Temperatures cool to below normal by Monday with 60s to 70s for
high temperatures on Tuesday. By Wednesday the upper level
trough moves into northern CA with a 40-60 percent chance of
showers developing over the area.

&&

.AVIATION...VFR. Isolated showers/thunderstorms along NV border,
capable of 30-40 kt gusts from downdrafts. Smoke layers.
Surface winds: variable 5-10kt becoming W-NW 5-15kt during the
afternoon. Winds aloft at 10kft MSL: N 5-15kt.

KBOI...VFR. Smoke layers. Surface winds: SE 5-10kt, becoming NW
5-10kt during the afternoon.

Weekend Outlook...Areas of smoke. Scattered showers and isolated
thunderstorms, with highest chance on Saturday. Drier conditions
on Sunday. Breezy winds during the afternoons.

&&

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

&&

$$

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SHORT TERM...KA
LONG TERM....KA
AVIATION.....KA