039
FNUS75 KBOI 190245
FWSBOI

Spot Forecast for Grizzly...Payette National Forest
National Weather Service Boise ID
845 PM MDT Sat Jul 18 2026

Forecast is based on forecast start time of 2100 MDT on July 18.
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 THROUGH TUES MORNING...
...STORM CHANCES INCREASE TUES AFTERNOON THRU THE WEEK...

.DISCUSSION...
High pressure keeps hot temperatures in the area through the
week. This weekend and Monday a lack of moisture keeps minimum RHs
around 20%. However, monsoonal moisture returns Tuesday leading
to an increased chance of thunderstorms, wetting rains, and wetter
minimum RHs. A 20-30% chance of thunder is expected Tuesday,
Wednesday, and Thursday afternoons. Minimum RHs climb to around
30% and morning RH climbs from 50% to 60-70%. Afternoon winds each
day are mildly breezy, with gusts 10-20 mph.

.REST OF TONIGHT...

Sky/weather.........Mostly cloudy late in the evening, then
                    clearing.
Min temperature.....62 to 67.
Max humidity........57 to 62 percent.
CWR.................0 percent.
Wind - 20 foot......Northeast around 10 mph, calming to 1 to 5 mph
                    early tomorrow morning.
Mixing height.......300 ft AGL.
Transport winds.....Northeast around 5 mph.
Ventilation Index...15 poor.

.SUNDAY...

Sky/weather.........Sunny.
Max temperature.....90 to 98.
Min humidity........17 to 22 percent.
CWR.................0 percent.
Wind - 20 foot......West-southwest 1 to 5 mph in the morning and
                    west 8 to 14 mph in the afternoon.
Mixing height.......7000 ft AGL.
Transport winds.....West around 10 mph.
Ventilation Index...700 excellent.

.SUNDAY NIGHT...

Sky/weather.........Mostly cloudy.
Min temperature.....63 to 68.
Max humidity........46 to 51 percent.
CWR.................0 percent.
Wind - 20 foot......North around 6 mph in the evening becoming less
                    than 3 mph overnight.
Mixing height.......400 ft AGL.
Transport winds.....East around 5 mph.
Ventilation Index...20 poor.

.MONDAY...

Sky/weather.........Cloudy in the morning then becoming partly
                    sunny in the afternoon.
Max temperature.....89 to 97.
Min humidity........19 to 24 percent.
CWR.................0 percent.
Wind - 20 foot......Less than 3 mph in the morning becoming north 3
                    to 5 mph in the afternoon.
Mixing height.......6000 ft AGL.
Transport winds.....Northwest around 10 mph.
Ventilation Index...600 good.

$$
Forecaster...Macfarlane
Requested by...IC Foelsch
Type of request...WILDFIRE
.TAG 2617724.0/BOI
.DELDT 07/18/26
.FormatterVersion 2.0.0
.EMAIL idpac@firenet.gov