206
FXUS65 KBOI 302017
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
217 PM MDT Fri Oct 30 2026

.KEY MESSAGES...

- Partial clearing tonight through Saturday morning.

- Widespread rain and high elevation snow late Saturday into
  Sunday, with the highest precipitation amounts across southern
  Idaho. A slight chance of thunderstorms Saturday evening.

- Cooler with gusty winds Sunday, and especially Sunday night,
  then drying and warming Monday through Wednesday. Slight
  chance of precipitation late week.

&&

.SHORT TERM /Through Sunday Night/...
The first of two pcpn events was exiting Idaho zones to the
northeast this afternoon. This will be followed by partial
clearing tonight before the next stronger system approaches
Friday. That system will include subtropical moisture, with
further enhancement by a developing cold front in OR. Rain
will spread northward into our CWA late Saturday, mostly on
the Idaho side, and will affect our CWA strongly Saturday night
through Sunday morning, with the cold front passing through
Sunday morning. SPC still has a slight chance of thunderstorms
Saturday afternoon and evening in southwestern Idaho. Latest
model QPF has increased slightly from the previous cycle for
Saturday afternoon through Sunday, with totals now estimated
.40 to 80 inch in Idaho mountains, .15 to .30 inch In Idaho
valleys and eastern Oregon mountains, and less than .10 inch
in OR valleys. Winds will shift to northwest Sunday and
increase Sunday afternoon, and especially Sunday night in the
Snake Basin, possibly reaching advisory criteria east of Boise
late Sunday night.

&&

.LONG TERM /Monday through Friday/...
Upper-level ridging will build over the western CONUS early
next week, returning dry conditions. Through the midweek, a
weak upper- level shortwave will move onshore and through
the Great Basin, although impacts are expected to be minimal.
Greater impacts are expected late week when another system
moves into the Pacific Northwest. Precipitation chances
currently reflect some disagreement when the system will move
in, but precipitation chances of 10-30% are currently forecast.
Temperatures will cool slightly at higher elevations while
holding nearly steady at lower elevations. Winds will generally
be light through the week with patchy fog expected in valleys.

&&

.AVIATION /18Z Friday through Saturday/...
Issued 1138 AM MDT FRI OCT 30 2026

Mainly VFR under mid to high clouds. Light rain with snow
above 6500-7500 ft MSL, mainly across SW Idaho, with MVFR-IFR
ceilings across higher terrain. A 10% chance of thunderstorms
in the Magic Valley this afternoon. Mountains obscured in
precipitation. Patchy valley fog developing tonight. Surface
winds: SE-SW 5-10 kt with gusts to 20 kt across higher terrain.
Winds aloft at 10kft MSL: S-SW 10-25 kt.

KBOI...VFR. Light rain moving in from the south ending by mid
afternoon. Surface winds: variable to SE 4-8 kt.

Weekend Outlook...Isolated to scattered showers through Saturday
afternoon, becoming widespread Saturday night. Isolated
thunderstorms across S Idaho late Saturday afternoon and
evening. Precipitation continuing through Sunday, tapering off
from W-E. VFR-MVFR in rain showers, IFR-LIFR in mountain snow.
Mountains obscured in precipitation. Snow levels: 6500-8000 ft
MSL Saturday, lowering to 5500-6500 ft MSL Sunday. Surface
winds: SW-SE 5-10 kt Saturday, then W-NW 10-20 kt with gusts
20-30 kt behind a cold front Sunday.

&&

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

&&

$$

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SHORT TERM...LC
LONG TERM....CH
AVIATION.....CH