Twin Falls, Idaho 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

644
FXUS65 KBOI 210921 CCA
AFDBOI

Area Forecast Discussion...CORRECTED
National Weather Service Boise ID
321 AM MDT Wed May 21 2025

.SHORT TERM...Today through Friday night...Today should be mostly
sunny, less windy, and about 5 degrees warmer than yesterday under
drier west-northwest flow aloft. A Pacific upper ridge will pass
through our CWA inland tonight, followed by an upper trough that
should reach the northwest coast early Thursday morning. The
trough is forecast inland across our northern zones Thursday
afternoon, exiting into Montana Thursday evening. After brief
ridging aloft Thursday night, another weaker Pacific trough will
come inland across OR Friday, and across our southern zones
Friday afternoon and Friday night. Both troughs will bring
light amounts of rain to our CWA, and also a slight (10-20
percent) chance of thunderstorms, first to our northern zones
Thursday and second to our southern zones Friday afternoon and
Friday night. Model PoPs look too high for the corresponding
light QPFs, especially for Thursday`s trough. We decided to
accept the more consistent QPFs and lowered the PoPs to match.

.LONG TERM...Saturday through Wednesday...The back end of a
longwave trough is expected to push out east across the northwest
and Great Basin regions on Saturday, paving the way for a
strong upper-level ridge to build into the entire U.S. west
Sunday and Monday. This pattern is expected to return
considerably warmer daytime temperatures and dry conditions
throughout the area on Sunday and Monday, with Monday likely
seeing daytime valley temperatures in the upper 80s and
potentially lower 90s. Daytime valley temperatures are expected
to remain in the mid to upper 80s on Tuesday, with a cooling
trend expected on Wednesday from a frontal approach. Snow levels
are expected to climb from the 7000-8000 ft range Saturday to
10,000+ ft Sunday to Wednesday. There remains considerable
uncertainty over model guidance on the arrival and magnitude of
either a closed low approaching the area or a long-range trough
digging across the Great Basin through Tuesday and Wednesday.
For now, forecast guidance is mainly hinting on slight
precipitation and thunderstorm chances over higher elevations
Tuesday through Wednesday.

&&

.AVIATION...VFR and clear skies overnight and early morning.
Surface winds: mostly light and variable 5-10 kt overnight and
Wednesday morning. Winds aloft at 10kft MSL: W 15-25 kt.

KBOI...VFR with clear skies. Winds light and variable overnight
and early morning.

&&

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

&&

$$

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SHORT TERM...LC
LONG TERM....JY
AVIATION.....JY