173
FXUS65 KBOI 072009
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
209 PM MDT Tue Oct 7 2025

.SHORT TERM...Tonight through Thursday night...No significant
changes from previous forecast. Continued dry and warming
through Thursday night as upper winds gradually back from
westerly to southerly, while a deepening upper low moves
southward off the NW coast. High temps will rise 5 to 8
degrees Wednesday and another 3 to 6 degrees Thursday. Low
temps will rise more slowly. By Friday morning the upper
level low will be centered near 44/130 off the OR coast,
close enough to increase clouds in Harney County. Surface
winds in our CWA will continue from the southeast 5 to 15
mph during the nights, and 10 to 20 mph during the days,
with afternoon gusts to 30 mph in the central Snake Plain
and in Harney County/OR.

.LONG TERM...Friday through Tuesday...A cold, closed low off
the PacNW Coast will move inland on Friday, supporting warm,
breezy, southerly flow and above normal temperatures across the
forecast area ahead of it. Precipitation chances will increase
Friday, and especially Friday night, as the low pulls in ample
Pacific moisture over the region. With pronounced southwest
flow continuing, favored areas for upslope flow will receive
the brunt of the moisture, such as the west-central/central
Idaho and Boise mountains (60-80% chance). Considerable
precipitation amounts are possible for the Friday night/early
Saturday morning period, with a 50% chance of exceeding 0.25
inches across the central Idaho terrain. Snow levels will
remain relatively high at this time, ranging at approximately
8k-9k feet MSL. As the low continues east Saturday, the cooler
airmass is expected to move overhead and plunge max temperatures
by 15 to 20 degrees for most locations. Winds will become gusty
from the west/northwest Saturday behind the cold front, and
precipitation chances will continue across the area. Snow
levels are forecast to drop to approximately 6k feet MSL
Saturday, then lower further on Sunday to around 5k feet MSL
with persistent cold air advection. This would result in light
snow amounts for high mountain valleys, such as the Long Valley,
with several inches of snow accumulation across the higher
elevations of NE Oregon and W-central portions of Idaho. Latest
model runs start to diverge Sunday night into early next week,
but are currently favoring cool, unsettled conditions with
troughing dominating the Northwest U.S.

&&

.AVIATION...VFR. Clear. Surface winds E-SE 5-15 kt. Winds aloft
at 10kft MSL: SE to S 5-15 kt, becoming S to SW 10- 20 kt around
Tue/21Z.

KBOI...VFR and clear. Surface winds: SE 5-12 kt.

&&

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

&&

$$

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SHORT TERM...LC
LONG TERM....SH
AVIATION.....SH