873
FNUS75 KBOI 212200
FWSBOI

Spot Forecast for Cottonwood III IA...USFS
National Weather Service Boise ID
400 PM MDT Wed May 21 2025

Forecast is based on ignition time of 0600 MDT on May 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.

...GUSTY WINDS THURSDAY...
...SCATTERED SHOWERS WITH A SLIGHT CHANCE OF STORMS THURSDAY...
...DRIER WITH CALMER WINDS FRI THROUGH SUN...

.DISCUSSION...
Afternoon gusts, shower potential, and transport winds blowing
across the Cottonwood Creek valley will make winds Thursday very
squirrelly. The exposure of the spot on a ridge gives some
confidence in tying down a few wind shifts. The most variable
winds will be on mid-slopes. A weak upper low moving through on
Thursday will produce scattered showers, with outflows up to 25
mph possible. Drying, calmer winds, and warming Friday through
early next week as upper level high pressure builds in.

.THURSDAY...

Sky/weather.........Partly sunny. A slight chance of showers and
weak thunderstorms in the afternoon. Chance of
precipitation 30 percent.
Max temperature.....61 to 67.
Min humidity........34 to 39 percent.
CWR.................10 percent.
Wind - 20 foot......Northeast 4 to 7 mph in the morning, becoming
                    south-southwesterly 5 to 8 mph around 9am local,
becoming northwesterly 12 to 18 mph in the
afternoon. Gusts up to 22 mph possible just
before the northwesterly wind switch, and last
through the afternoon. Local showers could
produce erratic gusts.
Mixing height.......8500 ft AGL.
Transport winds.....West 20 to 25 mph.
Ventilation Index...1700 excellent.

.THURSDAY NIGHT...

Sky/weather.........Mostly clear.
Min temperature.....40 to 45.
Max humidity........71 to 76 percent.
CWR.................0 percent.
Wind - 20 foot......North 4 to 10 mph. Gusts up to 18 mph in the
                    evening taper off after sunset.
Mixing height.......300 ft AGL.
Transport winds.....North around 5 mph.
Ventilation Index...15 poor.

.FRIDAY...

Sky/weather.........Sunny.
Max temperature.....62 to 68.
Min humidity........31 to 36 percent.
CWR.................0 percent.
Wind - 20 foot......Northwest 3 to 7 mph.
Mixing height.......8500 ft AGL.
Transport winds.....West around 5 mph.
Ventilation Index...425 fair.

$$
Forecaster...Macfarlane
Requested by...Gordon Wells
Type of request...PRESCRIBED
.TAG 2514072.4/BOI
.DELDT 05/22/25
.FormatterVersion 2.0.0
.EMAIL gordon.wells@usda.gov,jacob.miller3@usda.gov