509
FNUS75 KGJT 211224
FWSGJT

Spot Forecast for Slough Canyon...UTUBC
National Weather Service Grand Junction CO
624 AM MDT Fri Aug 21 2026

Forecast is based on forecast start time of 0700 MDT on August 21.
If conditions become unrepresentative, contact the National Weather
Service.

.DISCUSSION...Isolated afternoon showers and thunderstorms are
possible this afternoon with gusts to 35 mph and lightning being
the primary risks. Overnight into tomorrow, deeper monsoonal
moisture moves into the area to support more scattered afternoon
and evening showers and thunderstorms through the weekend. Some
storms will persist overnight. Brief periods of heavy rain are
possible in addition to lightning and gusty outflow winds.

.TODAY...

Sky/weather.........Mostly sunny (35-45 percent).
CWR.................5 percent.
Max temperature.....86-91.
Min humidity........16-21 percent.
Wind (20 ft)........Southwest winds 10 mph. Gusty and erratic winds
                    expected near thunderstorms in the afternoon.
Smoke dispersal.....Poor (34000 knot-ft) increasing to good in the
                    afternoon.
Mixing height.......5700 ft AGL increasing to 10600 ft AGL in the
                    afternoon.
Transport winds.....South 10 mph.
Clearing Index......340 increasing to 850 in the afternoon.
Chance of thunder...15 percent.

.TONIGHT...

Sky/weather.........Mostly cloudy (50-60 percent) then becoming
                    partly cloudy (45-55 percent).
CWR.................5 percent.
Min temperature.....64-69.
Max humidity........38-43 percent.
Wind (20 ft)........Northeast winds 10 mph. Gusty and erratic winds
                    expected near thunderstorms.
Smoke dispersal.....Fair decreasing to poor (4000 knot-ft)
                    overnight.
Mixing height.......8100 ft AGL decreasing to 600 ft AGL overnight.
Transport winds.....Southeast 10 mph.
Clearing Index......480 decreasing to 50 overnight.
Chance of thunder...15 percent.

.SATURDAY...

Sky/weather.........Mostly sunny (45-55 percent). Slight chance of
                    showers and thunderstorms in the afternoon.
CWR.................20 percent.
Max temperature.....81-86.
Min humidity........22-27 percent.
Wind (20 ft)........South winds 10 mph shifting to the southwest 15
                    mph in the afternoon. Gusty and erratic winds
                    expected near thunderstorms in the afternoon.
Smoke dispersal.....Poor (36000 knot-ft) increasing to very good in
                    the afternoon.
Mixing height.......4500 ft AGL increasing to 9100 ft AGL in the
                    afternoon.
Transport winds.....South 11 mph.
Clearing Index......360 increasing to 1050 in the afternoon.
Chance of thunder...30 percent.

$$
Forecaster...David Byers
Requested by...H Phillipson
Type of request...WILDFIRE
.TAG 2619987.4/GJT
.DELDT 08/21/26
.FormatterVersion 2.0.0
.EMAIL utubc@firenet.gov,tmaine@blm.gov