842
FXUS65 KBOI 091753
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
1153 AM MDT Sun Aug 9 2026

.UPDATE...Updated aviation discussion.

&&

.KEY MESSAGES...
- Smoke impacts continue through the start of the week.

- Breezy afternoon winds through Tuesday.

- Gradual cooling this week.

- Increasing shower and thunder chances Wednesday and beyond.

&&

.SHORT TERM /Through Tuesday Night/...
Issued 221 AM MDT SUN AUG 9 2026
The disturbance that crossed our area today will work to
suppress the high pressure aloft that has been dominating the
forecast, and allow for a slight cooling trend to kick off.
With the area under more zonal flow today and Monday, mid-level
monsoonal moisture will be shunted just to the south and east of
our area. Some virga showers can`t be ruled out come this
morning/early afternoon (mainly south of Twin Falls), however
any shower and thunderstorm development this the afternoon
should remain just outside of our area of responsibility. With
the Great Basin high pressure aloft weakening and shifting to be
over the Four Corners region, temperatures will gradually cool
to near normal come Tuesday. Breezy afternoon winds will persist
through Tuesday along ridgetops and the typical windy areas the
Snake Plain. In those areas, winds will generally gust to
around 20 mph, except to around 25 mph along ridgetops and in
the Camas Prairie. With fires continuing to burn, smoke impacts
will likely persist through the period.

&&

.LONG TERM /Wednesday through Sunday/...
Issued 221 AM MDT SUN AUG 9 2026
The gradual cooling trend will continue through the long-term period
as the high pressure aloft over the Four Corners region continues to
weaken. Temperatures will generally be near normal, perhaps even
leaning below normal to end the week. Troughing will begin to deepen
near the west coast through the start of the period, putting the
area under southwest flow aloft. This will allow for monsoonal
moisture to begin creeping north across our area again. Chances
for showers and thunderstorms will increase near the ID/NV
border as early as Wednesday, before expanding north with each
passing day. By Thursday, ensemble mean PWAT values reach the
85-90th percentile in our southern zones. With those values
encompassing our entire area come Saturday.

&&

.AVIATION /18Z Sunday through Monday/...
Issued 1146 AM MDT SUN AUG 9 2026

Generally VFR with periods of MVFR conditions near KONO-KEUL in
thicker smoke from nearby wildfires. Mountains obscured in
smoke. High density altitude with hot afternoon temperatures.
Surface winds: W-NW 5-10 kt, variable less than 10 kt overnight.
Winds aloft at 10kft: W-SW 10-20 kt.

KBOI...MVFR conditions in smoke improving to VFR conditions by
mid-afternoon. Foothills obscured in thicker smoke. High density
altitude with hot afternoon temperatures. Surface winds: NW 6-8
kt, variable less than 6 kt overnight.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Air Quality Alert until 1 PM MDT Monday for IDZ011>015-028-029-
     033.
OR...Air Quality Alert until 1 PM MDT /noon PDT/ Monday for
     ORZ061>064.
&&

$$

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AVIATION.....SA
SHORT TERM...NF
LONG TERM....NF