Bridgeport, Oregon Weather Forecast Discussion

890
FXUS65 KBOI 270808
AFDBOI
Area Forecast Discussion
National Weather Service Boise ID
208 AM MDT Sat Sep 27 2025
.SHORT TERM...Today through Monday night...Warm, dry, and clear
today through Sunday afternoon as we sit in the high pressure
saddle between a closed low over SoCal and an encroaching
Alaskan low. Temps warm to about 10 degrees above normal Sunday.
Sunday evening, the deep Alaskan low brings increased cloud
cover and steadily increasing chances of precipitation. Sunday
evening and night precip chances are 15-25%, with forcing
provided by the SoCal low becoming entrenched in the Alaskan
low`s jet stream. As heights gradually fall, temps fall closer
to what is climatologically normal for this time of year, with
Monday`s high temps being in the low 70s for lower elevations
and low 60s for mountain valleys. Monday afternoon and evening
precip chances increase drastically to 60-80% across the area.
While colder surface temps and cloud cover may inhibit
instability, thunderstorms are possible in orographically
induced convection, with a 20-30% chance of thunder across the
area. The abundant atmospheric moisture is forecast to produce
0.2-0.5 inches of rain in lower elevations, and 0.5-1 inch of
rain in higher elevations through Monday. Strong southwesterly
flow aloft may shadow valley locations, including the Treasure
valley, but the chances of receiving a tenth of an inch of
rainfall there is still 50%. The strong jet will mix down to
ridges and highlands, resulting in some localized 20-30 mph
gusts. Precipitation and cooling temperatures continue into the
long term.
LONG TERM...Tuesday through Saturday...Cooler unsettled weather
continues into the long term. A deep closed upper-level low,
resembling what would be a late fall/winter system, will slowly make
it`s way over our area. As this low approaches, embedded shortwaves
may act to locally enhance the dynamics of this system and bring
addition periods of precipitation. Models are in generally good
agreement on a shortwave and surface cold front pushing through the
area on Tuesday. Although with strong mid-level flow oriented out of
the southwest, some shadowing effects are possible. The highest
chances of precipitation Tuesday afternoon will be found in the
Central Idaho Mountains, ranging from 60-70%. Despite ample cloud
cover and cooler surface temperatures, the cooling temperatures
aloft and added dynamics of the trough will allow for enough
instability to support a slight chance of thunderstorms across
southwest Idaho come Tuesday afternoon. Periods of precipitation are
expected through Friday as our area continues to remain under the
influence of this trough. However, we will begin to dry out by
Saturday as it finally pushes off to the east. Temperatures will
hover 5-10 degrees below normal throughout the long term.
&&
.AVIATION...VFR and clear skies. Surface winds: variable up to 10kt,
becoming E-SE 5-10 kt by Sat/18z. Winds aloft at 10kft MSL: variable
5-10 kt.
KBOI...VFR. Surface winds: light and variable, becoming SE 5-10 kt
after Sat/13z.
Sunday Outlook...VFR. Increasing mid-high clouds throughout the day.
A 15-40% chance of showers and 10-20% chance of thunderstorms in S-
central Idaho after Sun/21z. Thunderstorms capable of localized
outflows of 30kt. Isolated showers continue across E-Oregon and SW-
Idaho after Mon/00z. Surface winds: SW-SE 10-20kt.
&&
.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
SHORT TERM...JM
LONG TERM....NF
AVIATION.....NF

NWS BOI Office Area Forecast Discussion