609
FXUS65 KBOI 301147
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
547 AM MDT Tue Jun 30 2026

.UPDATE...Updated aviation discussion.

&&

.KEY MESSAGES...
- Isolated showers and thunderstorms are expected Tuesday and
Wednesday afternoon and evening.

- Isolated thunderstorms confined to the central Idaho mountains
and near the Idaho-Nevada border Thursday and Friday, before drying
out this weekend.

- Steady warming trend throughout the week with dry
conditions and temperatures near normal on the 4th of July.

&&

.SHORT TERM /Through Thursday Night/...
Issued 219 AM MDT TUE JUN 30 2026
Early morning satellite imagery depicts broad troughing in place
across the Northwest, with scattered areas of mid-level cloud cover
present. Temperatures are generally running 2-5 degrees above
readings yesterday morning, with this difference likely to
continue into the daytime as a warming trend commences through
the week. Moisture values are above-normal as well, as evidenced
by surface dewpoints in the 40s and 50s throughout the Snake
Plain. This moisture will favor the development of isolated
showers and thunderstorms this afternoon as diurnal heating
results in modest destabilization. Storm intensity will
generally be limited by weak deep-layer shear, but brief gusty
outflow winds up to 50 mph could accompany storms. The most
widespread coverage will occur over the central Idaho mountains,
while isolated convection will extend westward into eastern
Oregon later this afternoon and evening.

By Wednesday, a general eastward disposition in moisture will occur
towards south-central Idaho, with the isolated thunderstorm threat
generally confined to the central Idaho Mountains and near the Idaho-
Nevada border. High temperatures in the 80s will also make a
return in the Snake Plain. The thunderstorm threat trends down
further on Thursday while temperatures tick up a few more
degrees.

&&

.LONG TERM /Friday through Tuesday/...
Issued 219 AM MDT TUE JUN 30 2026
A persistent and steady warming trend will define the second half of
this week, as flow aloft weakens while heat expands across much of
the western United States. Broad westerly flow aloft will feature a
couple weak disturbances which will promote isolated showers and
thunderstorms over the higher terrain of Idaho on Friday. However,
most of the lower elevations in Idaho, and all of eastern Idaho,
are expected to be dry on the 4th of July as a building ridge
across the northern Great Basin reduces any potential for
thunderstorms, despite sufficient moisture. The first 90 degree
temperatures of the week are also expected on Saturday in many
lower elevation areas, increasing to the mid-90s by Sunday.
Isolated showers and thunderstorms return to the higher terrain
Monday and Tuesday as southwest flow aloft strengthens again,
but hot temperatures will continue. is

&&

.AVIATION /12Z Tuesday through Wednesday/...
Issued 542 AM MDT TUE JUN 30 2026
VFR. Isolated showers and thunderstorms Tue/PM, mainly over the ID W-
Central mtns and near the ID/NV border. Thunderstorms capable of
30 kt outflows. Surface winds: Light and variable this morning,
then W-NW 8-12 kt Tue/PM. Winds aloft at 10kft MSL: W-NW 5-20
kt.

KBOI...VFR. Low chance of rain (<15%) Tue/PM. Surface winds: Light
and variable this morning then NW 5-10 kt Tue afternoon.

&&

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

OR...None.

&&

$$

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AVIATION.....JR
SHORT TERM...JR
LONG TERM....JR