620
FXUS65 KBOI 161720
AFDBOI

Area Forecast Discussion
National Weather Service Boise ID
1120 AM MDT Sun Aug 16 2026

.UPDATE...Updated aviation discussion.

&&

.KEY MESSAGES...
- Isolated showers and thunderstorms today and Monday favoring
  higher terrain, with outflows up to 40 mph and local downpours.

- Temperatures near or slightly above normal through mid-week,
  then further warming expected by late week.

- Return of monsoon moisture Friday into the weekend will
  increase shower and thunderstorm chances once again.

&&

.SHORT TERM /Through Tuesday Night/...
Issued 249 AM MDT SUN AUG 16 2026
Isolated showers and thunderstorms are lingering across south-
central Idaho and Magic Valley early this morning. Water vapor
imagery suggests drier conditions will follow the storms by mid
morning, effectively nudging the activity toward the east and
northeast. An upper ridge over the southern U.S. will begin to
amplify over the Intermountain West this afternoon, placing east
Oregon and southwest Idaho under warm, southwest flow aloft.
This will boost high temperatures a few degrees from Saturday to
slightly above normal. Swaths of Pacific moisture passing over
this ridge will combine with daytime instability this afternoon,
supporting the next round of shower and thunderstorm
development. Convection will be limited, however, with the best
dynamics over the higher terrain of northeast Oregon and
central/south-central Idaho. Wind gusts up to 40 mph and
localized heavy downpours will be the main concerns associated
with storms.

A weak disturbance will pass through the PacNW Monday and bring
additional moisture to the area, increasing cloud coverage and
promoting more convection Monday afternoon over the higher
terrain. Temperatures will remain above normal as southwest flow
and the ridge continue to influence the region. Showers may linger
into early Tuesday morning across central Idaho, with drying
elsewhere. Thereafter, the ridge will temporarily flatten on
Tuesday due to passing troughs to the north, decreasing the
moisture tap and lowering high temperatures by a couple of
degrees across the forecast area.

&&

.LONG TERM /Wednesday through Sunday/...
Issued 249 AM MDT SUN AUG 16 2026
Continued dry conditions and near normal temperatures are
anticipated Wednesday. Models depict a rebuilding of the upper
ridge into the region once again, reopening the door to warm
southerly flow and the return of monsoon moisture by Thursday
and Friday. Temperatures will become hot Thursday and Friday
under this pattern, with shower and thunderstorm chances
increasing both days. Meanwhile, a prominent, Pacific closed-
low will approach and move northeast through the PacNW beginning
Friday, clipping the forecast area through the weekend. Showers
and thunderstorm chances will persevere as the trough enhances
large-scale lift and carries moisture. Several degrees of
cooling will be likely for Saturday and Sunday.

&&

.AVIATION /18Z Sunday through Monday/...
Issued 1120 AM MDT SUN AUG 16 2026

Generally VFR. Areas of smoke reducing visibility in E Oregon.
This afternoon, isolated showers/thunderstorms around KBKE/KMYL
and KTWF/KJER with gusts up to 35 kt. Surface winds: variable
up to 10 kt through morning, except E-NE 10-20 kt for KJER/KTWF
area. Winds becoming SW-NW 5-15 kt in the afternoon. Winds
aloft at 10kft: SW 5-20 kt.

KBOI...VFR. Surface winds: SE 5-12 kt through morning, becoming
NW-N 5-12 kt in the afternoon.

&&

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

OR...None.

&&

$$

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AVIATION.....CH
SHORT TERM...SH
LONG TERM....SH