160
FXUS65 KBOI 231240
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
640 AM MDT Thu Jul 23 2026

.UPDATE...Updated aviation discussion.

&&

.KEY MESSAGES...
- Scattered showers and thunderstorms today across far eastern
  Oregon and far western Idaho, with gusty winds, lightning,
  brief heavy rain, and small hail possible.

- Very hot, dry, and breezy to end the week.

- Areas of smoke will continue through the week.

&&

.SHORT TERM /Through Saturday Night/...
Issued 353 AM MDT THU JUL 23 2026
An upper level low will spin off the coast today while an upper
level ridge begins to move to the east. This will usher in
southwesterly flow aloft, which will begin to push out deeper
monsoonal moisture. However, an area of moisture and instability
located over central Oregon this morning will move over the
Idaho/Oregon border this afternoon and early evening before
drier air arrives. Strong daytime heating will allow scattered
showers and thunderstorms to develop across far eastern Oregon
and far western Idaho, then drift northeast. Forecast soundings
reveal higher instability in the Treasure Valley today than
previous days, indicating potential for storms to reach the
Boise Metro area. Gusts up to 40-60 mph will be possible along
with frequent lightning, brief heavy rain, and small hail.
Southwest flow will also bring hotter temperatures with lower
valleys reaching 100-105 degrees, with a Heat Advisory beginning
this afternoon due to heat-related impacts. Winds will become
breezy across south-central Oregon this afternoon with gusts to
25 mph. Wildfire smoke will persist across the area today with
some improvement in the afternoon.

On Friday and Saturday, very dry air will arrive from the west
as the low slowly approaches the coast and southwest flow aloft
increases. Winds will become breezy each afternoon, strongest
on Saturday as the upper level low moves into western
Washington. Gusts Saturday across southeast Oregon and the
higher elevations of southwest Idaho could reach 30-40 mph. Very
dry air combined with gusty winds may bring critical fire
weather conditions. Temperatures will remain very hot,
especially on Friday when some lower valley locations will
approach 107 degrees. Shower and thunderstorm potential (10-20%
chance) will be limited to south-central Idaho, where monsoonal
moisture will hang on for a couple more days. Wildfire smoke
will linger over the area, mainly each night and morning with
daytime mixing improving afternoon conditions.

&&

.LONG TERM /Sunday through Thursday/...
Issued 353 AM MDT THU JUL 23 2026
The pattern through the extended will be very similar to late
this week, but more moderated with slow day-to-day changes. An
upper level trough along/off the coast and upper level ridging
to our east will continue dry southwest flow across the area.
Temperatures will remain hot, although slightly cooler thanks to
the trough with lower valleys reaching the mid 90s.
Temperatures may increase several degrees by the end of the
period as the ridge builds back to the west. Winds will remain
breezy, but not as strong as Saturday due to a weaker pressure
gradient. Dry air will keep shower and thunderstorm chances
minimal, but will tick up across south-central Idaho to 10-20%
by mid to late week as the ridge expands and allows monsoonal
moisture back into eastern areas.

&&

.AVIATION /12Z Thursday through Friday/...
Issued 621 AM MDT THU JUL 23 2026
Generally VFR, with areas of MVFR due to wildfire smoke.
Visibility will be at a minimum this morning, with improvement
during the peak of daytime heating. Showers and thunderstorms
will redevelop this afternoon across far eastern Oregon and far
western Idaho, impacting KBOI/KEUL/KONO/KBKE/KMYL. Outflow gusts
30-50 kt, brief heavy rain, and small hail possible from storms.
High density altitude due to heat this afternoon. Surface
winds: variable less than 10 kt this morning, becoming SW-NW
5-15 kt this afternoon. Winds aloft at 10kft MSL: SW 10-20 kt.

KBOI...VFR, low chance of MVFR visibility due to wildfire smoke.
High density altitude due to heat this afternoon. Showers and
thunderstorms possible between 22Z Thursday and 02Z Friday.
Surface winds: variable to SE less than 10 kt this morning
becoming WNW 5-10 kt after 21Z.

Weekend Outlook...Areas of wildfire smoke continuing with worse
conditions at night/morning and improvement each afternoon. High
density altitude due to heat. Isolated showers and thunderstorms
across the Magic Valley each afternoon, mostly clear elsewhere.
Surface winds: SW-NW 5-15 kt with gusts to 25 kt, except 10-20
kt with gusts to 30 kt on Saturday.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Air Quality Alert until 2 PM MDT Friday for IDZ011-012-014-033.
     Fire Weather Watch from Friday afternoon through Saturday
     evening for IDZ401-402-423.
     Heat Advisory from 2 PM this afternoon to 9 PM MDT Saturday
     for IDZ012-014-016-033.
OR...Air Quality Alert until 2 PM MDT /1 PM PDT/ Friday for
     ORZ061>064.
     Fire Weather Watch from Friday afternoon through Saturday
     evening for ORZ670>675.
     Heat Advisory from 2 PM MDT /1 PM PDT/ this afternoon to 9 PM
     MDT /8 PM PDT/ Saturday for ORZ063-064.
     Red Flag Warning from noon MDT /11 AM PDT/ today to 9 PM MDT
     /8 PM PDT/ this evening for ORZ673>675.
&&

$$

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AVIATION.....ST
SHORT TERM...ST
LONG TERM....ST