FXUS65 KBOI 180601
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
1201 AM MDT Mon May 18 2026

.UPDATE...Updated aviation discussion.

&&

.KEY MESSAGES...
- Breezy conditions overnight, with frost and freeze possible in
  the Snake Plain, mostly east of Mountain Home. 

- Mountain showers on Monday, otherwise dry, breezy and 
  slightly warmer. 

- Dry with temperatures warming back above normal starting on
  Wednesday.

&&

.SHORT TERM /Through Tuesday Night/...
Issued 237 PM MDT SUN MAY 17 2026
Widely scattered showers this evening will dissipate with
sunset, leaving dry conditions and clear skies overnight. The
surface pressure gradient behind an eastward exiting low will
keep breezy conditions across portions of SE Oregon and through
much of the Snake Plain tonight. Low temperatures briefly drop 
to around freezing Monday morning in portions of the Snake Plain,
reaching 31 to 35 degrees east of Mountain Home, while the lower
Snake will fall to between 36 and 40 degrees. Have stayed with a
Freeze Warning for the western Magic Valley. Monday will be dry
and breezy across much of the area, though not as windy as today
with gusts of 25-35 mph expected. Afternoon instability will
support a slight chance of showers over the mtns but amounts
will be light. Northwest flow aloft carries into Tuesday, but a
more stable air mass will keep conditions dry across the region
as temperatures warm back to near normal.

&&

.LONG TERM /Wednesday through Sunday/...
Issued 237 PM MDT SUN MAY 17 2026
High pressure building in aloft over the Pacific will keep our
area under northwest flow to start the period. Wednesday into 
Thursday will feature increased cloud cover and light, isolated 
showers across the West Central Mountains, as an embedded 
shortwave moves through the intermountain west. This shortwave 
will also work to slow the warming trend in the long-term 
period. Come Saturday, a deepening Alaska low will give way to 
zonal flow aloft. Daytime highs of 5-10 degrees above normal and
generally dry conditions are expected through the weekend.

&&

.AVIATION /06Z Monday through Tuesday/...
Issued 1155 PM MDT SUN MAY 17 2026

Generally VFR. Patchy fog/stratus in sheltered mtn valleys through 
morning. Scattered showers redevelop Monday PM across E Oregon and 
mtns of SW Idaho. Brief MVFR/IFR and obscuration in mtn precip. 
Monday snow levels: 5500-6500 ft MSL. Surface winds: W-N 10-20 kt 
with areas of gusts to 20-25 kt. Winds aloft at 10kft MSL: N-NE 20-
35 kt.

KBOI...VFR. Foothill showers return Monday PM. Surface winds: W-NW 5-
15 kt overnight, then NW 10-18 kt with gusts around 25 kt after 
Mon/16Z.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...Wind Advisory until midnight MDT tonight for IDZ012-014-015-
     029.
     Freeze Warning until 8 AM MDT Monday for IDZ016.
OR...Wind Advisory until midnight MDT /11 PM PDT/ tonight for 
     ORZ061>064.
&&

$$

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