028
FXUS65 KBOI 310934
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
334 AM MDT Sun Aug 31 2025

.SHORT TERM...Today through Tuesday night...Heat will build over
the region through Monday as an upper ridge amplifies across
the interior western US. Conditions are a touch more stable
today across Baker County and the w-central ID, so while mtn
cumulus development is likely, don`t expect it to be deep enough
to produce lightning. Do expect to see some taller buildups
over Harney County this afternoon and have edged up the chance
of a shower or thunderstorm to around 10%. Given the development
the last few days, honestly wouldn`t be surprised to see a cell
overachieve this evening. Today will run 1-3 degrees warmer
than yesterday, with another 1-3 degrees of warming into Monday.
This will place lower elevations in the upper 90s, and wouldn`t
be surprised to see a couple of 100 degree highs on Monday as a
surface thermal trough over Oregon pulls SE winds through the
Snake Plain. A more southerly flow aloft sets up Monday into
Tuesday as the ridge axis shifts eastward. This will draw
moisture northward, lifting precipitable water values to over
0.75 inches, which is certainly enough to support shower/storm
development. Thus have increased precipitation chances across SE
Oregon and areas south of the Snake Plain in Idaho starting
Monday, but more so for Tuesday. Will also be watching the
timing of a weak low lifting northward through CA late Tue/Wed
which could enhance afternoon development or even introduce a
nocturnal threat Tuesday night.

.LONG TERM...Wednesday through Sunday...The CA low will likely
still be in play over the area on Wednesday. Models favor
tracking the low center through Oregon, which would favor SE
Oregon and far SW Idaho for a continued chance of showers and
thunderstorms. From there we`ll be looking for a potential
breakdown of the upper ridge late in the week into next weekend.
While there are differences in how it evolves, both the GFS and
ECMWF show a break in the heat and increased chances of rain
unfolding by the weekend. These solutions lineup with the
ensemble consensus which has temperatures returning to near
normal and a broad 20-30% chance of showers/storms starting on
Saturday. Interestingly the operational Canadian model keeps the
ridge and summer heat in place through the period.

&&

.AVIATION...Generally VFR. Smoke layers through about 20kft MSL
will reduce visibility. A 10% chance of showers/thunderstorms
Sunday afternoon across Harney County (KBNO) into mtns west of
KBKE. Surface winds: variable up to 10 kt becoming E-S 5-15 kt
with local gusts to 25kt by 31/16Z. Winds aloft at 10kft MSL:
S-SE 5-15 kt.

KBOI...Some reduction in visibility due to smoke but remaining
VFR. Easterly surface winds continuing through Monday.

&&

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

&&

$$

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