115
FNUS75 KBOI 211935
FWSBOI

Spot Forecast for Box...BLM
National Weather Service Boise ID
135 PM MDT Thu Aug 21 2025

Forecast is based on forecast start time of 0600 MDT on August 22.
If conditions become unrepresentative...contact the National Weather
Service.

Please contact our office at (208)334-9060, if you have questions
or concerns with this forecast.

...HOT AND DRY WITH EVENING WIND SURGE ON FRIDAY...

...UNSTABLE ON SATURDAY WITH THUNDERSTORM OUTFLOWS A RISK...

.DISCUSSION...
Hot and dry with breezy afternoon winds from the north to
northeast. An evening surge in winds is expected to reach the fire
around 2000 MDT Friday, with winds shifting more to the east and
gusts up to 30 mph possible until 0600 Saturday. Winds then easing
slightly into the morning on Saturday and returning to a north to
northeast flow. Very hot, dry and unstable conditions on
Saturday, with mixing heights in excess of 15000 ft which may lead
to enhanced convective plume development. While there is a slight
chance of thunderstorms forming to the south near the ID-NV
border Saturday afternoon and evening, they are expected to remain
well away from the fire. However, associated outflows could lead
to gusts up to 40 mph reaching the fire from around 1400 Saturday.
Poor RH recoveries overnight. Smoke may concentrate in local
valleys overnight Friday into Saturday beneath an inversion.

.FRIDAY...

Sky/weather.........Sunny.
Max temperature.....94 to 99.
Min humidity........12 to 17 percent.
CWR.................0 percent.
Wind - 20 foot......North to northeast 10-15 mph. Gusts up to
                    20 mph in the afternoon.
Mixing height.......11500 ft AGL.
Transport winds.....West around 20 mph.
Ventilation Index...1150 excellent.

.FRIDAY NIGHT...

Sky/weather.........Mostly cloudy in the evening then becoming
                    partly cloudy overnight.
Min temperature.....66 to 71.
Max humidity........20 to 25 percent.
CWR.................0 percent.
Wind - 20 foot......East to northeast around 10-15 mph. Gusts up
                    to 20-30 mph in the evening.
Mixing height.......200 ft AGL.
Transport winds.....East around 25 mph.
Ventilation Index...20 poor.

.SATURDAY...

Sky/weather.........Partly cloudy.
Max temperature.....96 to 101.
Min humidity........11 to 16 percent.
CWR.................0 percent.
Wind - 20 foot......North to northeast around 10 mph. Gusts up to
                    15 mph.
Mixing height.......13500 ft AGL.
Transport winds.....West around 15 mph.
Ventilation Index...1350 excellent.

$$
Forecaster...Zhou
Requested by...Idaho Team 1
Type of request...WILDFIRE
.TAG 2520388.0/BOI
.DELDT 08/22/25
.FormatterVersion 2.0.0
.EMAIL 2025.box.plans@firenet.gov