039
FNUS75 KBOI 302051
FWSBOI

Spot Forecast for Big Grass Fire...USFS
National Weather Service Boise ID
251 PM MDT Thu Jul 30 2026

Forecast is based on forecast start time of 0700 MDT on July 31.
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.

...FIRE WEATHER WATCH IN EFFECT FROM SATURDAY AFTERNOON THROUGH
SATURDAY EVENING FOR DRY/WINDY CONDITIONS...
...WINDY CONDITIONS CONTINUE THROUGH MONDAY MORNING...

.DISCUSSION...
Today and tomorrow hot, dry, and mildly breezy conditions
continue. Gusty winds alongside a dry cold frontal passage this
weekend have prompted the issuance of a Fire Weather Watch
Saturday afternoon and evening. Westerly winds 15 to 20 mph with
gusts up to 30 mph move through the fire alongside minimum RHs of
5 to 10% during the Watch. While RHs begin to rise around sunset,
winds at the fire will be gusting 15 to 25 mph through Monday
morning. Minimum RHs each day hold relatively steady through the
forecast at 5 to 15% each day.

.FRIDAY...

Sky/weather.........Sunny.
Max temperature.....95 to 100.
Min humidity........6 to 11 percent.
CWR.................0 percent.
Wind - 20 foot......West 6 to 12 mph. Gusts up to 18 mph in the
                    afternoon.
Mixing height.......12000 ft AGL.
Transport winds.....Southwest around 10 mph.

.FRIDAY NIGHT...

Sky/weather.........Mostly clear.
Min temperature.....61 to 66.
Max humidity........20 to 26 percent.
CWR.................0 percent.
Wind - 20 foot......South 4 to 10 mph. Gusts up to 18 mph in the
                    evening.
Mixing height.......200 ft AGL.
Transport winds.....South around 5 mph.

.SATURDAY...

Sky/weather.........Mostly sunny.
Max temperature.....96 to 104.
Min humidity........7 to 12 percent.
CWR.................0 percent.
Wind - 20 foot......South 3 to 6 mph in the morning shifting to the
                    west 10 to 16 mph with gusts to around 22 to 26 mph in
                    the afternoon.
Mixing height.......11000 ft AGL.
Transport winds.....West around 15 mph.

$$
Forecaster...Macfarlane
Requested by...Matt Brown FBAN
Type of request...WILDFIRE
.TAG 2618438.6/BOI
.DELDT 07/31/26
.FormatterVersion 2.0.0
.EMAIL matt.brown@sccfd.org