388
FXUS65 KBOI 281634
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
1034 AM MDT Sat Jun 28 2025

.DISCUSSION...Dry westerly flow continues today with breezy west
to northwest winds in the afternoon, and cumulus buildups over
the mountains. Updated the forecast to add more mention of
thunder in the extended period as the monsoon moisture
increases after Monday. Hot temperatures expected Monday and
Tuesday as the ridge amplifies over the west with temperatures
10-15 degrees above normal.

&&

.AVIATION...VFR. Generally clear.  Surface winds: W-NW 5-15 kt.
Afternoon gusts 15-25 kt in the Snake Basin. Winds aloft at 10kft
MSL: W 15-25 kt.

KBOI...VFR. Generally clear. Surface winds: NW 6-12 kt. Afternoon
gusts to 20 kt.

Sunday Outlook...VFR and mostly clear. Surface winds NW 5-15 kt.

&&

.PREV DISCUSSION...
SHORT TERM...Today through Monday night...Zonal flow through
Sunday with an amplifying ridge to our south. While the zonal
flow keeps weather mostly quiet, the ridge will cause a warming
trend that sharply increases Monday as the the flow gains a
southwesterly component. Temps warm from about normal on
Saturday to 10-15 degrees above normal by Monday. The ridge
amplifies and becomes a four-corners high, and supplemented by a
closed low off the SoCal coast we`ll enter a typical monsoonal
setup, bringing isolated thunderstorms to Southeast Oregon and
far Southwest Idaho on Monday evening.

LONG TERM...Tuesday through Saturday...Peak warming during the
period on Tuesday as the ridge axis remains fixed over the area,
with afternoon high temps in the Snake Plain being near to a few
degrees above 100 degrees. This comes at the same time as peak
monsoonal moisture arrives as the SoCal low moves inland,
bringing more thunderstorms to much of southeastern and eastern
Oregon, and highlands in southwest Idaho. The low becomes
embedded in the jet stream on Wednesday, bringing another pocket
of moisture through the area and dropping temps slightly to 5-10
degrees above normal. While the heat is hazardous alone, the
inclusion of the encroaching low and thunderstorm chances make
Tuesday and Wednesday potentially critical fire weather days.
We remain unsettled Thursday through Saturday as another upper
low sits north of the area, supporting a chance of thunderstorms
each afternoon.

&&

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

&&

$$

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DISCUSSION...KA
AVIATION.....ST
SHORT TERM...JM
LONG TERM....JM