518
FXUS65 KBOI 081047
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
447 AM MDT Sat Aug 8 2026

.UPDATE...Updated aviation discussion.

&&

.KEY MESSAGES...
- Continued hot through Sunday then gradual cooling through
  next week.

- Smoke persisting through the weekend into next week.

- Breezy afternoon winds through Monday.

- Isolated late-day thunderstorms near the ID/NV border Saturday
  and Sunday as high-level monsoon moisture advances northward.

&&

.SHORT TERM /Through Monday Night/...
Issued 203 AM MDT SAT AUG 8 2026
Hot and Smoky conditions will continue to persist through the
weekend. This afternoon is looking to be the hottest day of the
period...However wildfire smoke will likely help keep
temperatures a couple degrees cooler than what they could be.
With satellite imagery before sunset and webcams showing a dense
smoke plume working it way towards our area, have opted to
lower the forecast temperature this afternoon. Even with the
smoke, it will still be hot with lower elevation and high
desert temperatures reaching 95-103 degrees. A weak upper-level
disturbance will work its way though late Saturday into Sunday,
and give way to a cooling trend come Sunday and Monday. With
temperatures cooling to near normal by Monday. this disturbance
will also bring breezy conditions through Monday. The strongest
gusts, however, will come each evening with the Baker Valley
drainage winds in Oregon; here, evening gusts will be as high as
25-30 mph.

A push of monsoonal moisture will continue to work its way up
to the ID/NV border come this afternoon and Sunday afternoon.
This moisture, paired with weak instability, will give way to a
slight chance of showers and thunderstorms both afternoons near
the ID/NV border. Model soundings prog a very dry boundary
layer, with surface relative humidity generally ranging from
10-15%. With this, little (if any) precip will reach the ground
out of any showers/thunderstorms that develop. However, with
deep inverted-v soundings, even virga showers can produce gusty
and erratic outflows. The disturbance mentioned prior will push
the mid-level moisture south and east, ending the risk of
showers/thunder come Monday.

&&

.LONG TERM /Tuesday through Saturday/...
Issued 203 AM MDT SAT AUG 8 2026
A gradual cooling trend will set in for the long-term period, as
the Great Basin high pressure aloft weakens and shifts towards
the Four Corners region. Near zonal flow aloft will keep the
area dry for the start of the long-term period. Come mid-week
this coming week, a deepening trough near the west coast will
put our area under more southwesterly flow aloft. This will
allow for mid-level moisture to work its way north again. The
LREF mean has positive PWAT anomalies reaching the Nevada
border come Thursday, continuing to push north through the end
of the period. This will allow for increasing chances of showers
and thunderstorms to end the coming work week. At the end of
the period, timing becomes uncertain on when the aforementioned
trough will come across our area.

&&

.AVIATION /12Z Saturday through Sunday/...
Issued 447 AM MDT SAT AUG 8 2026

MVFR-IFR visibility and mountain obscuration due to wildfire smoke.
High density altitude due to hot afternoon temperatures. A 15%
chance of thunder along the ID/NV border this afternoon. Surface
winds: Variable 5-10 kt this morning, becoming W-NW 10-20 kt
this afternoon. Winds aloft at 10kft MSL: W-SW 10-20 kt.

KBOI...Smoke from nearby wildfires impacting visibility with
periods of MVFR conditions. Periods of foothill obscuration.
Surface winds: Light 3-8 kt SE this morning, becoming NW 5-10
kt with gusts up to 18 kt this afternoon.

Sunday Outlook...Areas of MVFR/IFR visibility and local
mountain obscuration due to wildfire smoke. High density
altitude due to hot temperatures. A 15% chance of afternoon
thunderstorms along ID/NV border. Surface winds: W-NW 5-15 kt
with gusts 15 to 25 kt Sunday/PM, otherwise variable less than
10 kt.


&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Air Quality Alert until 1 PM MDT Monday for IDZ011>015-028-029-
     033.
     Heat Advisory until 9 PM MDT this evening for IDZ012-014>016-
     029-030-033.
OR...Air Quality Alert until 1 PM MDT /noon PDT/ Monday for
     ORZ061>064.
     Heat Advisory until 9 PM MDT /8 PM PDT/ this evening for
     ORZ061>064.
&&

$$

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