Twin Falls, Idaho 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

113
FXUS65 KBOI 212054
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
254 PM MDT Wed May 21 2025

.SHORT TERM...Tonight through Friday night...An upper shortwave
trough will lift through the Pac NW on Thursday bringing a
chance of showers and thunderstorms to e-central Oregon and
w-central Idaho. Dynamics of this wave will support early
morning development across Baker County and northern
Harney/Malhuer counties. Don`t expect much to reach the ground
with this early development. Afternoon instability will fuel
greater coverage and support a chance of thunderstorms. Wind
gust potential from the storms will be 40 mph. The western Magic
Valley and highlands along the NV border will see generally
windy conditions develop in the afternoon as the southwest flow
aloft mixes to the surfaces. Gusts of 30 to 40 mph will be
common in this area through early evening. A cold frontal
passage in the afternoon/evening will shift winds to the W-NW
across the region. The air mass stabilizes Thursday night behind
the front with winds calming down. The chance for showers
returns on Friday as a weaker trailing upper trough moves into
the West. The better dynamics and instability are across Harney
and Malheur counties and areas south of the Snake Plain in
Idaho. Have a 20-30% chance of showers and ~15% chance of
thunderstorms in this area for Friday afternoon. The Snake Plain
remains to stable/dry while a low chance (<20%) of showers
resides across the w-central Idaho mtns. Temperatures are near
normal through Friday.

.LONG TERM...Saturday through Wednesday...The longwave troughing
pattern that brought thunderstorms Friday will be making its
way further East, replaced by the building of a potent longwave
ridge over Western CONUS. This will dig its heels in and persist
until mid Monday. A steady temperature climb and dry conditions
can be expected during this time. Current forecast has the
upper & lower Treasure Valley peaking in the upper 80s to
possibly (30-50%) low 90s Monday afternoon. Late Monday through
Wednesday, the upper-level ridge moves east and digs in again,
giving way to weak shortwave troughing becoming semi-stationary
over the West Coast. This will cause daytime temps to
stagnate/cool a bit Tuesday and Wednesday. Precipitation chances
will also come back with this troughing, with notable amounts
forecast in Harney, Baker, and Valley counties during
afternoon/evening Monday, Tuesday, and Wednesday. Snow levels
are expected to climb to 9,000+ ft MSL Sunday to Wednesday.

&&

.AVIATION...VFR and clear skies overnight. Early morning
precipitation and lower ceilings possible in Eastern Oregon,
however timing and coverage too uncertain to mention in TAFs
yet. Surface winds: light and variable 5-10 kt becoming SE 5-10
kt overnight in SW ID and W-NW 5-10 kt in SE OR. Winds aloft at
10kft MSL: W 10-20 kt becoming SW-S 15-25 kts.

KBOI...VFR with clear skies. Surface winds light and variable
tonight becoming 4-7 kt SE overnight. Thursday afternoon winds
will swing around to W-NW 7-12 kt.

&&

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

&&

$$

www.weather.gov/Boise

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SHORT TERM...DG
LONG TERM....CH
AVIATION.....CH