420
FXUS65 KBOI 220911
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
311 AM MDT Fri Aug 22 2025

.SHORT TERM...Today through Sunday night...The Four Corners high
drifts westward through Saturday resulting in a building upper
ridge and a warming trend with valley highs in the 90s to near
100F, which is about 10 degrees above normal. Monsoon moisture
wrapping around the high could reach far southern areas along
the Nevada border by Saturday afternoon or evening for a slight
chance (less than 20 percent) of showers and thunderstorms. The
ridge weakens slightly on Sunday while the moisture advects
further northward into our area. The shower/thunderstorms
are still confined to southern areas, but the chances increase
to 30-60 percent near the Nevada border. Temperatures are not as
hot, around 3 to 6 degrees lower as compared to Saturday.

.LONG TERM...Monday through Friday...Monsoon moisture continues
to advect into the region and spreads northward through midweek,
remaining in place through the end of the week. Daytime heating
will promote a chance of afternoon-evening showers and
thunderstorms, with the potential for gusty winds and heavy
rainfall. Temperatures trend slightly cooler each day to
slightly below normal by Thursday.

&&

.AVIATION...Areas of MVFR to LIFR in wildfire smoke in
W-Central Idaho including KMYL, creating mtn obscuration. Smoke
layers expanding south into Boise Mtns Friday. Surface winds:
variable 10 kt or less through morning, then NE-NW 5-15 kt Fri
afternoon. Winds aloft at 10kft MSL: variable 5-15 kt.

KBOI...VFR. Light smoke layers Friday. Surface winds: SE and
variable under 10 kt Fri morning, then NW 5-10 kt Fri afternoon.

Weekend Outlook...Mainly VFR. Visibility reductions and mtn
obscuration in W-Central Idaho due to wildfire smoke. A 10-15%
chance of showers/thunderstorms in SE Oregon Saturday PM, then
20-40% chance of storms near the NV border Sunday PM. Variable
5-15 kt surface winds, except gusty/erratic winds 35-45 kt near
thunderstorms.

&&

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

&&

$$

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SHORT TERM...BW
LONG TERM....BW
AVIATION.....JY