451
FXUS65 KBOI 010926
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
326 AM MDT Mon Sep 1 2025

.SHORT TERM...Today through Wednesday night...High pressure
aloft will keep summer like temperatures over the region as we
enter the first month of fall. The next couple of days will see
highs flirt with 100 degrees across the lower Snake Plain while
mtn valleys approach 90. This will put some sites close to
records today and especially Tuesday which looks to be the
hottest day. Otherwise will keep an eye on elevated moisture
that has maintained just enough of a presence to fuel afternoon
showers and thunderstorms the last couple of days. Today the
focus is across southern Malheur and Owyhee counties. The FV3
(which typically runs hot with shower/storm development) has
been doing well and is one of a couple model solutions to show
showers entering the lower Treasure Valley this afternoon in the
vicinity of Caldwell. All this said, have beefed up
precipitation chances (15-20%) in these areas. Tuesday and
Wednesday will see a minor upper low lift north through Oregon.
This system will increase shower and thunderstorm coverage
across SE Oregon and far SW Idaho Tuesday and Tuesday night.
Current model output shows the upper ridge axis holding strong
which keeps precipitation from extending further eastward
through the day Wednesday. Wednesday is hot, but a few degrees
off of Tuesday`s peak.

.LONG TERM...Thursday through Monday...The upper ridge starts to
weaken on Thursday, and this trend looks likely to continue
through the weekend as energy pushes in from the coast.
Precipitation coverage will increase starting Friday, with a
broad 20-40% chance of daytime showers and thunderstorms
through Monday. Precipitable water values could top out over an
inch Fri/Sat, introducing the potential for heavy rain.
Temperatures gradually cool down to near normal by Sun/Mon.

&&

.AVIATION...VFR. Smoke layers aloft through around 20kft MSL. A
10-20% chance of virga showers/thunderstorms across far SE
Oregon and SW Idaho between 18Z and 03Z today. Surface winds:
S-E 5-15 kt with localized gusts to around 20 kt along I-84
corridor (KBKE-KGNG). Winds aloft at 10kft MSL: S 10-20 kt.

KBOI...VFR. Smoke layers aloft creating hazy skies. Easterly
surface winds through the day.

&&

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

&&

$$

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SHORT TERM...DG
LONG TERM....DG
AVIATION.....DG