029
FNUS75 KBOI 072330
FWSBOI

Spot Forecast for Big Grass...BLM...UPDATED
National Weather Service Boise ID
530 PM MDT Mon Sep 7 2026

Forecast is based on forecast start time of 1800 MDT on September 07.
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.

...WARMING AND DRYING THROUGH THURSDAY...
...BREEZY WINDS THURSDAY THROUGH SATURDAY...

.DISCUSSION...
High pressure will gradually build over the area and bring mostly
clear skies, warmer than normal temperatures, and light diurnal
winds later today through Wednesday. A mostly dry low pressure
system will arrive Thursday through the weekend, bringing breezy
westerly winds and a cooldown to near-normal temperatures. The burn
area is expected to remain dry throughout the week.

.TONIGHT...

Sky/weather.........Mostly clear.
Min temperature.....38 to 45.
Max humidity........70 to 80 percent.
CWR.................0 percent.
Wind - 20 foot......Northwest 3 to 7 mph in the evening shifting to
                    the east 3 to 7 mph after sunset.
Mixing height.......100 ft AGL.
Transport winds.....East around 5 mph.
Ventilation Index...5 poor.

.TUESDAY...

Sky/weather.........Sunny.
Max temperature.....70 to 77.
Min humidity........19 to 29 percent.
CWR.................0 percent.
Wind - 20 foot......East 3 to 6 mph in the morning shifting
                    to the northwest 3 to 7 mph in the afternoon.
Mixing height.......6000 ft AGL.
Transport winds.....West around 5 mph.
Ventilation Index...300 fair.

.TUESDAY NIGHT...

Sky/weather.........Mostly clear.
Min temperature.....43 to 50.
Max humidity........61 to 71 percent.
CWR.................0 percent.
Wind - 20 foot......Northwest in the early evening, shifting to
                    northeast 5 to 9 mph after sunset.
Mixing height.......100 ft AGL.
Transport winds.....Southeast around 5 mph.
Ventilation Index...5 poor.

.WEDNESDAY...

Sky/weather.........Mostly sunny.
Max temperature.....78 to 85.
Min humidity........14 to 22 percent.
CWR.................0 percent.
Wind - 20 foot......East 3 to 6 mph in the morning shifting
                    to northwest 3 to 6 mph in the afternoon.
Mixing height.......6500 ft AGL.
Transport winds.....West around 5 mph.
Ventilation Index...325 fair.

$$
Forecaster...Yang
Requested by...Alicia Schlarb
Type of request...WILDFIRE
.TAG 2621344.1/BOI
.DELDT 09/07/26
.FormatterVersion 2.0.0
.EMAIL 2026.biggrass.plans@firenet.gov