145
FXUS65 KBOI 092012
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
212 PM MDT Sat May 9 2026

.KEY MESSAGES...
- About ten degrees hotter Sunday, with lower elevations
  reaching 90 degrees for the first time this year.

- Record high temps on Tuesday with temperatures in the mid to
  upper 90s in the lower valleys.

- Cooler Wednesday with a chance of showers and thunderstorms.

&&

.SHORT TERM /Through Monday Night/...
Breezy west-northwest winds this afternoon. Gusts to 30 mph in
south-central Idaho and the Camas Prairie. Lighter winds in
Idaho Sunday afternoon, but stronger in Harney County where
gusts will reach 35 mph.  A broad upper level ridge of high
pressure centered along the coast today will amplify as it moves
inland tonight and Sunday, resulting about ten degrees warming
from today. High temps will be near 90 degrees in the Treasure
Valley and southern Malheur County/OR. A weak but faster-moving
embedded short wave will pass by to the north Monday with some
middle and high clouds and 1-3 degrees cooling from Sunday.

&&

.LONG TERM /Tuesday through Saturday/...
Daytime high temperatures will set records come Tuesday as high
pressure aloft will allow temperatures to climb to 20-25 degrees
above normal (in the 90s for lower elevations valleys). These
temps may be among the hottest ever recorded so early in the
season. While the air will be hot, water temperatures will still
be cold, so it may be good to consider taking extra precautions
if planning to recreate on the water.

Guidance is coming into better alignment on a trough making its
way through the Intermountain West come Wednesday/Thursday.
Ahead of this trough, a surge of moisture from this south will
increase precipitable water values to the 80-90th percentile of
climatology. This pattern evolution is favorable for thunderstorms
across our area. As a result of this trough, precipitation and
thunder chances will increase through Wednesday afternoon. The
thunderstorm threat, compounded with breezy winds and low
relative humidities, will result in an elevated fire weather
risk where fuels are dry. Temperatures will begin to trend
cooler beginning Wednesday, to more seasonable values by the
end of the week. Precipitation chances will taper off at the
end of the week, as upper-level ridging builds in briefly behind
the trough. Come Saturday, another shortwave will begin to dig
down the British Columbia coast toward our area.

&&

.AVIATION /18Z Saturday through Sunday/...
Issued 1145 AM MDT SAT MAY 9 2026

VFR. Surface winds: W-NW 5-15 kt with gusts to 25 kt this
afternoon near KTWF/KJER. Becoming variable 5-10 kt overnight.
Winds aloft at 10 kft MSL: NW 5-20 kt.

KBOI...VFR. Surface winds: NW 8-12 kt with occasional gusts up
to 18 kt this afternoon. Becoming SE 5-10 kt overnight.

Sunday Outlook...VFR. Surface winds SW-SE 5-15 kt with gusts to
25 kt in SE Oregon. A cold front Sunday night will bring NW
gusts of 15-30 kt.

&&

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

OR...None.

&&

$$

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SHORT TERM...LC
LONG TERM....NF/LC
AVIATION.....NF