822
FXUS65 KBOI 021513
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
913 AM MDT Tue Sep 2 2025

.DISCUSSION...No forecast changes.  Continued hot through Friday
although slightly cooler after today. Gradually increasing PoPs
in eastern OR and near the NV/ID border beginning Thursday as
monsoon moisture surges northward. More significant cooling and
better chance of showers/thunderstorms this weekend as a Pacific
upper trough swings inland across CA and into OR and taps into
the monsoon moisture, which then shifts to our east Sunday.

&&

.AVIATION...VFR. Smoke layers aloft. High density altitude in
the afternoon due to heat. Virga and isolated showers/thunderstorms
near NV border and in SE Oregon after 20Z, capable of 30-40 kt
gusts. Surface Winds: variable 5-15 kt. Winds aloft at 10kft
MSL: variable less than kt.

KBOI...VFR. Smoke layers aloft. High density altitude in the
afternoon due to heat. Surface winds: SE 5-10 kt, becoming NW
5-10 kt during the afternoon.

&&

.PREV DISCUSSION...
SHORT TERM...Today through Thursday night...A ridge of high
pressure will continue to strengthen over the western US today
with continued hot conditions. Temperatures will be around 15
degrees above normal with near record high temperatures today.
Boise will be near 100F and the record is 101F set in 2022.
Monsoon moisture across the Great Basin will move north today
over the NV border with a slight chance of thunderstorms this
afternoon. Upper level clouds will continue to move northward
from the Great Basin on Wednesday afternoon into Thursday with a
slight chance of showers and thunderstorms, mainly along the NV
border. Temperatures slightly cool on Wednesday and Thursday as
the ridge slowly weakens.

LONG TERM...Friday through Tuesday...A trough will approach the
OR and northern CA coast on Friday. The dynamics of this trough
will interact with the monsoon moisture already in place, with a
20-30 percent chance of thunderstorms across eastern OR and far
southwest ID, and a 10-20 percent chance of thunderstorms north
and east of the Snake Plain. A piece of the trough swings inland
on Saturday, with a 20-40 percent chance of showers and
thunderstorms. Temperatures cool to near normal on Saturday.
Showers and thunderstorms linger into Sunday and Monday as the
trough remains just offshore, with moisture lingering over the
Rocky Mountains. The trough is forecast to slowly move inland
during the Tuesday-Thursday timeframe with cooler and unsettled
conditions continuing.

&&

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

&&

$$

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DISCUSSION...LC
AVIATION.....LC
SHORT TERM...KA
LONG TERM....KA