056
FNUS75 KBOI 211116
FWSBOI

Spot Forecast for West Castle Rock RX...Vale BLM
National Weather Service Boise ID
416 AM MST Fri Nov 21 2025

Forecast is based on ignition time of 0700 MST on November 21.
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.

...DRY AND STABLE WITH INVERSION IN PLACE...

.DISCUSSION...
Dry and stable conditions expect through Sunday night under
a weak upper level high pressure. Valley fog/stratus will be
persistent especially Saturday and Sunday. This will also keep
poor mixing and ventilation with mixing heights between 1000
and 1500 feet AGL. A cold front late Sunday into Monday could
be strong enough to break the inversion as well as bring light
rain/snow showers.

.REST OF TODAY...

Sky/weather.........Sunny in the morning then becoming partly sunny
                    in the afternoon.
Max temperature.....39 to 47.
Min humidity........59 to 66 percent.
CWR.................0 percent.
Wind - 20 foot......West 3 to 4 mph in the morning shifting to the
                    south around 4 mph in the afternoon.
Mixing height.......1500 ft AGL.
Transport winds.....Southwest around 5 mph.
Ventilation Index...75 poor.

.TONIGHT...

Sky/weather.........Mostly cloudy.
Min temperature.....31 to 36.
Max humidity........85 to 90 percent.
CWR.................0 percent.
Wind - 20 foot......West around 3 mph.
Mixing height.......100 ft AGL.
Transport winds.....Southwest around 5 mph.
Ventilation Index...5 poor.

.SATURDAY...

Sky/weather.........Partly sunny.
Max temperature.....38 to 46.
Min humidity........60 to 66 percent.
CWR.................0 percent.
Wind - 20 foot......Less than 3 mph in the morning becoming
                    southeast 3 to 5 mph in the afternoon.
Mixing height.......1000 ft AGL.
Transport winds.....South around 5 mph.
Ventilation Index...50 poor.

$$
Forecaster...Smith
Requested by...Vale Dispatch
Type of request...PRESCRIBED
.TAG 2526427.1/BOI
.DELDT 11/21/25
.FormatterVersion 2.0.0
.EMAIL orvac@firenet.gov