198
FNUS75 KGJT 182345
FWSGJT

Spot Forecast for Derby Fire...Grand Junction Interagency Dispatch Center
National Weather Service Grand Junction CO
545 PM MDT Mon Aug 18 2025

Forecast is based on forecast start time of 1800 MDT on August 18.
If conditions become unrepresentative, contact the National Weather
Service.

.DISCUSSION...

Hot and dry conditions continue through the period. Critical fire
weather conditions are not expected to develop through the period
as winds remain below criteria. A non zero chance for showers and
thunderstorms emerges Wednesday, but remains a low confidence
likelihood with the best chances well to the south of the fire.
Wetting rains are not expected.

.TONIGHT...

Sky/weather.........Mostly clear (5-15 percent).
CWR.................0 percent.
Min temperature.....46-51.
Max humidity........29-34 percent.
Wind (20 ft)........Northwest winds 5-10 mph.
Smoke dispersal.....Good decreasing to poor (0 knot-ft) overnight.
Mixing height.......9500 ft AGL decreasing to 0 ft AGL overnight.
Transport winds.....Northwest 10 mph.
Chance of thunder...0 percent.

.TUESDAY...

Sky/weather.........Sunny (15-25 percent).
CWR.................0 percent.
Max temperature.....70-75.
Min humidity........10-15 percent.
Wind (20 ft)........Northeast winds 5 mph shifting to the southeast
                    in the afternoon at 8-12 mph with gusts to 15 mph.
Smoke dispersal.....Good.
Mixing height.......6800 ft AGL increasing to 10100 ft AGL in the
                    afternoon.
Transport winds.....West 10 mph.
Chance of thunder...0 percent.

.TUESDAY NIGHT...

Sky/weather.........Mostly clear (5-15 percent).
CWR.................0 percent.
Min temperature.....46-51.
Max humidity........44-49 percent.
Wind (20 ft)........North winds 5-10 mph.
Smoke dispersal.....Fair decreasing to poor (0 knot-ft) overnight.
Mixing height.......8300 ft AGL decreasing to 0 ft AGL overnight.
Transport winds.....North 10 mph shifting to the south overnight.
Chance of thunder...0 percent.

.WEDNESDAY...

Sky/weather.........Sunny (15-25 percent).
CWR.................0 percent.
Max temperature.....72-77.
Min humidity........12-17 percent.
Wind (20 ft)........South winds 10 mph shifting to the west in the
                    afternoon at 10-15 mph.
Smoke dispersal.....Fair increasing to good in the afternoon.
Mixing height.......6000 ft AGL increasing to 10800 ft AGL in the
                    afternoon.
Transport winds.....West 10 mph shifting to the northwest in the
                    afternoon at 15 mph.
Chance of thunder...10 percent.

$$
Forecaster...Lucas Boyer
Requested by...Theodore Donoghue
Type of request...WILDFIRE
.TAG 2520172.0/GJT
.DELDT 08/18/25
.FormatterVersion 2.0.0
.EMAIL cogjc@firenet.gov