617
FXUS65 KBOI 111527
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
927 AM MDT Sat Oct 11 2025

Much cooler today as upper low comes inland from the northwest
coast. High temps 15 degrees cooler than yesterday in Harney
County, to as much as 30 degrees cooler in Twin Falls County.
Another 5 degrees cooler Sunday as the upper low passes directly
overhead. Showers continuing through tonight in northern areas,
with snow level lowering to 5500 feet MSL tonight. Fewer
showers in the south, mainly over mountains. Isolated
thunderstorms through this evening. Showers decreasing south to
north overnight and decreasing further from east to west Sunday.
Moderate northwest winds (10 to 20 mph) through Sunday.
Strongest afternoon gusts (25 to 30 mph) in the central Snake
Basin and in Malheur County. Current forecast aligns well with
latest models. No updates.

&&

.AVIATION...VFR. Scattered showers in the Magic Valley, with
isolated to scattered showers developing elsewhere in the
afternoon. Mountains obscured at times. Snow levels 6000-7500ft
MSL, lowering to 6000-6500ft this afternoon. Surface winds: W-NW
5-15kt, gusts to 15-30kt in the afternoon. Stronger showers may
produce gusty winds up to 35kt and graupel. Winds aloft at
10kft MSL: SW-W 15-30 kt becoming W-NW 15-30kt in the afternoon.

KBOI...VFR. 10-15 percent chance of showers in the afternoon.
Surface winds: NW 5-10 kt, becoming 10-15kt with gusts to 25 kt
in the afternoon.

Sunday Outlook...North of the Snake River Plain and KBKE area...
rain/snow showers continue with periods of low VFR/MVFR in rain,
IFR/LIFR in snow with mountains obscured. Snow levels 5-6kft
MSL. Elsewhere...VFR. Surface winds: generally SW-NW 10-15 kt,
gusts to 20-25 kt.

&&

.PREV DISCUSSION...
SHORT TERM...Today through Monday night...An upper level trough
over southwest WA will slowly move eastward today and weaken.
Central and eastern OR remain in a dry slot of the system, with
dry conditions through this morning. The trough will move
eastward later today, with cooler air moving overhead by late
this afternoon. Snow levels fall to around 6000-6500` MSL this
afternoon, and temperatures at 500mb fall to around -25C,
causing steep lapse rates and unstable conditions this afternoon.
Periods of sunshine this morning and afternoon will be favorable
for scattered shower development late this afternoon and early
evening. Some of the stronger showers may produce graupel and
gusts up to 35 mph during the afternoon. Unstable conditions
continue into Sunday morning with rain and snow showers favored
over the higher terrain of the west central ID mountains. A
reinforcement of cold air from the north retrogrades into
another low pressure system off the Pacific NW coast on Monday,
shifting the flow to southwest again, with moderating
temperatures. Rain and snow showers possible over central and
eastern OR on Monday morning, with precipitation generally
staying west of a line from Ontario OR to Rome OR.

LONG TERM...Tuesday through Saturday...A cutoff low pressure
system moves south along the coast and digs into southern NV/CA
by Wednesday with wrap around subtropical moisture impacting
the area Tuesday and Wednesday. Todays model suites now favor
upper level ridging on Thursday and Friday with warmer
temperatures. While both the deterministic and ensemble guidance
show good agreement on the overall pattern, forecast confidence
remains low due to the extreme amount of energy coming out of
the western Pacific due to the typhoons moving into the jet
stream upstream of us. Notably Typhoon Halong and the
interaction with the jet stream as it becomes a hurricane force
low in the Bering Sea this weekend. These complex interactions
have historically been poorly handled by the model suites and
this time will be no different. TLDR, the forecast will change
greatly each day even if there is good model agreement in the
extended over the next week due to the tropical systems upstream
of us.

&&

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

&&

$$

www.weather.gov/Boise

Interact with us via social media:
www.facebook.com/NWSBoise
www.x.com/NWSBoise

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