National Weather Service United States Department of Commerce

COZ203-061145-
COZ203-061145-
Lower Colorado River-
141 PM MDT Thu Aug 5 2021

Fire Weather Planning Forecast for Wrn Colorado and Ern Utah
National Weather Service Grand Junction CO
141 PM MDT Thu Aug 5 2021

...RED FLAG WARNING IN EFFECT FROM NOON TO 8 PM MDT FRIDAY FOR
GUSTY WINDS, LOW HUMIDITY AND DRY FUELS FOR COLORADO FIRE WEATHER 
ZONES 200, 202, AS WELL AS ZONE 203 BELOW 7500 FEET AND UTAH FIRE 
WEATHER ZONE 490...

.DISCUSSION...

High pressure centered overhead will maintain warm and dry conditions 
across much of eastern Utah and western Colorado this evening. Exceptions 
include the Southwest San Juans where a few isolated thunderstorms may 
develop through this evening and a weak disturbance drifting over northeast 
Utah, which will initiate a few storms along the eastern Uintas. Conditions 
begin to shift tomorrow as prefrontal winds increase across much of the 
region in the afternoon. In combination with drying conditions, critical 
conditions will be reached for susceptible fuels. Thus, Red Flag Warnings 
have been issued for these areas in coordination with fuel specialists. 
Localized fire weather conditions may resurface over the weekend while high 
pressure remains suppressed to the south and a series of troughs pass the 
region to the north.

...GUSTY ERRATIC WINDS CAN BE EXPECTED NEAR ANY SHOWERS
OR THUNDERSTORMS...
...THE SMOKE DATA IS CALCULATED FROM AN AVERAGE AT 6000 FEET MSL...


...RED FLAG WARNING IN EFFECT FROM NOON TO 8 PM MDT FRIDAY FOR
GUSTY WINDS, LOW HUMIDITY AND DRY FUELS FOR COLORADO FIRE WEATHER 
ZONES 200, 202, AS WELL AS ZONE 203 BELOW 7500 FEET AND UTAH FIRE 
WEATHER ZONE 490...

.Tonight...
Sky/weather.........Clear (0-10%) until 2400, then partly cloudy 
                    (30-40%). Areas of smoke until 2400, patchy smoke 
                    after 2400. 
Min temperature.....61-71 F near 6000 feet 
                    54-64 F near 8000 feet. 
Max humidity........25-35%. 
20-foot winds.......Upslope/upvalley 4 to 8 mph becoming 
                    downslope/downvalley 3 to 6 mph by sunset.
CWR.................0 percent. 
LAL.................1.
Haines Index........6 or high. 
15K Ft MSL Winds....West 10 to 15 mph increasing to 20 to 25 mph 
                    after midnight. 
Mixing Height.......9000 ft AGL until 2000, then 1000 ft AGL. 
Transport Winds.....Southwest 5 mph until 2400, then southeast. 
Smoke dispersal.....Poor. 

.FRIDAY...
Sky/weather.........Partly cloudy (30-40%) until 1200, then mostly 
                    sunny (20-30%). Patchy smoke. Isolated showers 
                    and thunderstorms after 1200. 
Max temperature.....85-95 F near 6000 feet 
                    75-85 F near 8000 feet. 
Min humidity........10-15%. 
20-foot winds.......Downslope/downvalley winds 4 to 8 mph becoming 
                    southwest 15 to 20 mph in the afternoon. 
                    Localized gusts up to 35 mph. 
CWR.................10 percent. 
LAL.................1 until 1200, then 2.
Haines Index........6 or high. 
15K Ft MSL Winds....Southwest 20 to 30 mph increasing to 30 to 40 
                    mph in the afternoon. 
Mixing Height.......1000 ft AGL until 0900. 14500 ft AGL after 
                    1000. 
Transport Winds.....Southwest 5 to 10 mph until 1200, then 20 to 30 
                    mph. 
Smoke dispersal.....Poor until 0900. Excellent after 1200. 

.FRIDAY NIGHT...
Sky/weather.........Partly cloudy (30-40%). Isolated showers and 
                    thunderstorms until 2400. Smoke until 2400, 
                    then areas of smoke. 
Min temperature.....53-63 F near 6000 feet 
                    46-56 F near 8000 feet. 
Max humidity........31-41%. 
20-foot winds.......West winds 10 to 15 mph in the evening becoming 
                    downslope/downvalley 3 to 6 mph by sunset. 
                    Localized gusts up to 35 mph. 
CWR.................10 percent. 
LAL.................2 until 2400, then 1.
Haines Index........6 or high. 
15K Ft MSL Winds....West 25 to 35 mph. 
Mixing Height.......13000 ft AGL until 2000, then 1000 ft AGL. 
Transport Winds.....West 15 to 20 mph until 2400, then northwest 5 
                    mph. 
Smoke dispersal.....Excellent until 2100. Poor after 2400. 

.SATURDAY...
Sky/weather.........Sunny (0-10%). Areas of smoke until 1200. 
Max temperature.....79-89 F near 6000 feet 
                    71-81 F near 8000 feet. 
Min humidity........9-14%. 
20-foot winds.......Upslope/upvalley winds 4 to 8 mph. Localized 
                    gusts up to 20 mph in the afternoon. 
CWR.................0 percent. 
LAL.................1.
Haines Index........5 or moderate. 
15K Ft MSL Winds....Northwest 20 to 30 mph decreasing to 15 to 20 
                    mph in the afternoon. 
Mixing Height.......1500 ft AGL until 0800, then 10500 ft AGL. 
Transport Winds.....Northwest 5 mph. 
Smoke dispersal.....Poor until 0900. Good after 1200. 

.FORECAST FOR DAY 3 THROUGH 7...
.SUNDAY...Clear. Lows 55-65. Highs 87-97. Southwest winds 10 to
20 mph with gusts to  30 mph. 
.MONDAY...Clear. Lows 57-67. Highs 86-96. Southwest winds 10 to
20 mph with gusts to  30 mph. 
.TUESDAY...Mostly clear. Isolated showers and thunderstorms. Lows
56-66. Highs 85-95. Winds less than 15 mph. 
.WEDNESDAY...Mostly clear. Isolated showers and thunderstorms.
Lows 56-66. Highs 84-94. 
.THURSDAY...Mostly clear. Isolated showers and thunderstorms.
Lows 56-66. Highs 85-95.