Nampa, Idaho 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

502
FXUS65 KBOI 232018
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
218 PM MDT Tue Jun 23 2026

.KEY MESSAGES...
- Temperatures continuing 5 to 10 degrees above normal through
  Thursday.

- Slight chance of thunderstorms over higher terrain Wednesday
  and Thursday afternoons with gusty outflow winds but little,
  if any, rain.

- Major weather change beginning Friday with arrival of a north
  Pacific cold front.  Showers, thunderstorms, gusty winds, and
  much cooler air lasting through Monday. Snow possible as low
  as 6500 feet MSL Saturday night and Sunday.

&&

.SHORT TERM /Through Thursday Night/...
A weak upper ridge will maintain hot weather through Thursday
with enough instability for isolated high-based afternoon and
evening thunderstorms. Storms will produce gusty outflow winds
but little, if any, rain. A strong north Pacific cold front
will pass through eastern Oregon pre-dawn Friday, beginning a
change to wetter and much cooler weather.

&&

.LONG TERM /Friday through Tuesday/...
A closed upper low will steer into the northwest region from off the
coast of British Columbia on Friday. This pattern will bring a cold
front through southwest ID on Friday with cooler and unsettled
conditions through Saturday and Sunday. Widespread showers and
thunderstorms are expected throughout Friday with this frontal
passage, with the highest chances in the afternoon. There is
slightly better guidance agreement over the upper low center
moving right over our area on Saturday. As such, Saturday and
Sunday will see the highest chances of wetting rain, mainly over
the west-central ID mountains, with temperatures as much as
20-30 degrees below normal area-wide. With snow levels expected
to drop down into the 6000-7000 ft MSL range by early Sunday,
light snowfall remains possible on mountain peaks late Saturday
through Sunday morning. Conditions dry out with breezy
conditions on Monday and Tuesday as the system moves northeast
into west-central Canada. Our area will likely stay under a
drier shortwave trough behind the system and remain in a cooler
pattern from a northwest flow early next week.

&&

.AVIATION /18Z Tuesday through Wednesday/...
Issued 1129 AM MDT TUE JUN 23 2026
VFR and patchy smoke over Treasure Valley areas. High density
altitude during the afternoon due to heat. Isolated showers/
thunderstorms near OR/NV border in the late afternoon through
evening, with gusty outflows up to 35 kt over SE OR. Surface
winds: variable or E-SE 5-15 kt becoming NW-NE 5-15 kt in the
afternoon. Winds aloft at 10kft MSL: W-NW 10-20 kt, then S- SW
5-15 kt in the afternoon.

KBOI...VFR. High density altitude during afternoon from heat.
Surface winds: SE 5-10 kt becoming NW 5-15 kt in the afternoon
after 20Z.

&&

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

&&

$$

www.weather.gov/Boise

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