FXUS65 KBOI 210957

AFDBOI



Area Forecast Discussion

National Weather Service Boise ID

357 AM MDT Sun Jun 21 2026



.KEY MESSAGES...

- Daytime temperatures remaining near normal through Sunday,

  then warming to around 10 degrees above normal Tuesday through

  Thursday.



- Breezy afternoons over the next several days.



- Cooler and unsettled conditions possible next weekend.



&&



.SHORT TERM /Through Tuesday Night/...

An upper level trough will remain over Alberta over the next

several days with west-northwest flow on Sunday. Isolated

showers and thunderstorms will form over the central ID

mountains and southern Twin Falls County along the NV border

this afternoon. Breezy west-northwest winds this afternoon and

again on Monday afternoon. The system over Alberta will slowly

move east and upper level ridging will bring warmer 

temperatures by Tuesday with temperatures warming to around 10 

degrees above normal. Subtropical moisture will begin to get

injected into the upper level ridge after Tuesday, but westerly

flow will keep the deeper moisture to the south and east of our

area.



&&



.LONG TERM /Wednesday through Sunday/...

Dry and warm conditions continue into Thursday, with subtropical

moisture remaining south and east of the area. Some showers and

thunderstorms may form in the central ID mountains and south 

along the NV border Thursday afternoon. An upper level trough

from the Gulf of Alaska will move southeast into the Pacific NW

late Thursday. A cold front moves through southeast OR and

southwest ID on Friday with cooler and unsettled conditions 

possible Saturday and Sunday. Still significant model 

differences in the positioning of this trough, but wetting rains

possible next weekend and much cooler temperatures as much as 

10-20 degrees below normal.



&&



.AVIATION /06Z Sunday through Monday/...

Issued 1209 AM MDT SUN JUN 21 2026

Possible mountain valley fog/stratus where recent rain 

occurred. Otherwise, VFR and clearing skies overnight. Isolated 

thunderstorms developing near ID/NV border Sunday afternoon. 

Surface winds: variable 12 kt or less. Then, W-N 5-15 kt with 

gusts to 15-20 kt Sunday afternoon. Winds aloft at 10kft: 

westerly 10-20 kt.



KBOI...VFR. Clouds clearing overnight. Surface winds: variable or SE 

up to 10 kt overnight, then W-NW 5-15 kt by late Sun morning.



&&



.BOI WATCHES/WARNINGS/ADVISORIES...

ID...None.



OR...None.



&&



$$



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SHORT TERM...KA

LONG TERM....KA

AVIATION.....SH