FXUS65 KBOI 302005
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
205 PM MDT Wed Apr 30 2025

.SHORT TERM...Tonight through Friday night...Mostly clear skies
will continue this afternoon and evening, aside from some
cumulus development and a few isolated showers over the Central
Idaho Mountains. Breezy northwesterly winds, with gusts up to 30
MPH across the Snake River Plain, will diminish by sunset. With
drier air moving into the region, fog and stratus are not
expected to redevelop overnight.

An upper-level ridge will build over the area late tonight and
persist through much of Friday, bringing a continued warming and
drying trend. Temperatures will rise from the mid-70s on
Thursday to the low 80s by Friday in the Treasure Valley.
Southeasterly winds will strengthen Friday as the next upper-
level trough approaches the West Coast, potentially boosting
temperatures a few more degrees. There’s a 15% chance that highs
in the Treasure Valley could exceed 85 degrees.

Showers are expected to develop ahead of the trough axis across
central Oregon and Harney County late Friday into early
Saturday. The latest model guidance now shows the trough digging
further south, which would slow its eastward movement and reduce
precipitation chances. However, there appears to be enough
instability to support a slight chance of thunderstorms in
Harney County.

.LONG TERM...Saturday through Wednesday...A deep longwave
trough will develop into a cut off low and dive to our south on
Saturday morning. This will bring a strong push of cold air with
widespread precipitation through Sunday. Heavier showers and
colder air will be develop south of the Snake River Plain, with
up to 1 inch of liquid precipitation anticipated over high
terrain near the NV border by Monday morning. Thunderstorms are
likely both Saturday and Sunday afternoon, capable of producing
gusty winds, heavy rain, and small hail. The cooler airmass will
also lower snow levels overnight on Saturday and Sunday,
bringing a wet snow to elevations as low as 6000 feet.
Accumulations will likely be minimal. Some wraparound showers
will bring lingering rain to higher terrain in the region on
Monday. A ridge will develop over the northwest on Monday
evening, bringing a warming and drying trend through next
Wednesday. Temperatures will warm to about 3-8 degrees above
normal by next Wednesday, with light winds anticipated each day.

&&

.AVIATION...VFR with patchy mountain valley fog tomorrow morning,
mainly near KMYL. Surface winds: NW 5-15 kt gusting to 25 kt this
afternoon in the Snake River Valley, tapering off to variable less
than 10 kt overnight. Winds aloft at 10kft MSL: NW to NE 10-20 kt.

KBOI...Mostly VFR. Surface winds: NW 10-15 kt with gusts to 25 kt
during the afternoon, tapering off to variable less than 5 kt by the
early evening.

&&

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

&&

$$

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SHORT TERM...JDS
LONG TERM....SA
AVIATION.....SA