Horseshoe Bend, Idaho Weather Forecast Discussion

429
FXUS65 KBOI 230829
AFDBOI
Area Forecast Discussion
National Weather Service Boise ID
229 AM MDT Tue Sep 23 2025
.SHORT TERM...Today through Thursday night...Clear skies,
except smoky mostly in OR, due to wildfires in WA. The
smoke should decrease from east to west today and tonight
via easterly winds at low levels. We also have an upper
level ridge over our area. The ridge is forecast to hold
nearly stationary through Thursday bringing dry air and
warmer temps.  By Thursday highs will be in the mid 70s to
mid 80s in the mountains, and mid to upper 80s in the lower
valleys, i.e., 10 to 12 degrees above normal. Lows will
warm more slowly resulting in diurnal temperature ranges
as large as 50 degrees in eastern OR. Surface winds will
be mainly east or southeast 5-15 mph through Thursday
except 15 to 25 mph today in the Snake Basin between
Mountain Home and Gooding.
.LONG TERM...Friday through Tuesday...A cool, shallow trough
will pass to the north early Friday morning while sweeping a
dry cold front through the forecast area. As a result, gusty
west/northwest winds and 6 to 9 degrees of cooling can be
expected Friday in the wake of this front, but precipitation
chances will be negligible. Upper flow will transition to a
warmer, west-southwest over the weekend as a prominent Gulf
of Alaska low approaches and deepens along the West Coast.
Meanwhile, long range models now indicate that a closed low
over CA/NV will become an open wave and send moisture northward
into southern Idaho on Sunday. This solution will increase the
probability of showers and thunderstorms for Sunday afternoon
and evening, favoring the southwest/south-central Idaho
mountains. Thereafter, the Gulf of Alaska low is forecast to
move onshore on Monday, sending a plume of Pacific moisture
into the northwest U.S. While models still disagree on the
strength and timing of this low, cooling temperatures and a
boost in precipitation chances are expected early next week
for E Oregon and SW Idaho.
&&
.AVIATION...VFR. Smoke layers from WA fires are currently
reducing low level visibility for east Oregon and southwest/
west-central Idaho near the OR border. Improving from E to W
by early afternoon. Surface winds: variable up to 10 kt, then
generally NE-SE 5-15 kt this afternoon. Winds aloft at 10kft
MSL: NW to NE 10-20 kt.
KBOI...VFR. Light smoke layers near the surface will clear out
from SE to NW between 12Z-15Z this morning. Surface winds: S to
SE 4-12 kt. Gusts to 15-20 kt late morning and early afternoon.
&&
.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...LC
LONG TERM....SH
AVIATION.....SH

NWS BOI Office Area Forecast Discussion