FNUS76 KOTX 072236
FWSOTX

Spot Forecast for Chelan Hills...SE Washington Type 3 Team
National Weather Service Spokane WA
336 PM PDT Tue Jul 7 2026

Forecast is based on forecast start time of 0600 PDT on July 08. 
...RED FLAG WARNING IN EFFECT UNTIL 10 PM PDT THIS EVENING...
...RED FLAG WARNING IN EFFECT FROM 11 AM TO 10 PM PDT WEDNESDAY...

.DISCUSSION...

The passage of a dry cold front Wednesday morning will lead to
another day of critical fire weather conditons. While the front
will bring lower daytime temperatures and higher minimum relative
humidities compared to Tuesday, values will still be critical and
winds will be even breezier. Winds will initially be light and 
out of the northwest to begin the day, then steadily increase 
throughout the morning. The nocturnal inversion will lift around 
0800 hours and erode through the morning thereafter. A subtle wind
shift from northwesterly to west-northwesterly will occur between
1200 hours and 1400 hours, then shift back to northwesterly with 
speeds further increasing through the afternoon. Winds will then 
diminish between 1900 hours and 2100 hours Wednesday before making
another subtle westerly shift and becoming light Wednesday night.
Hot and dry weather continues into Thursday with westerly winds 
becoming breezy again Thursday afternoon.

If conditions become unrepresentative, contact the National Weather
Service.
***************************************************************
Forecasts for 20 foot wind speeds (valleys and ridge tops) are
10 minute averages reflecting RAWS wind.
***Ventilation Index is derived from transport wind
   multiplied by the mixing height divided by 100.
   Categories: low (< 200), moderate (200-500), 
   high (500-800), and very high (> 800). 
***************************************************************

.WEDNESDAY...

Sky/weather.........Sunny. 
CWR.................0 percent. 
Chance of lightning.0 percent. 
Max temperature.....85-92. 
Min humidity........19 to 24 percent. 
Wind (20 ft)........Northwesterly winds 6 to 11 mph through 0900 hours
                    increasing to 12 to 18mph by 1200 hours. West to 
                    northwest winds 7 to 15 mph from 1200 to 1400 hours, 
                    then northwest winds increase to 18 to 25mph through 
                    the afternoon. Gusts up to 35 mph in the afternoon. 
                    Windiest conditions across the ridgetops.
Mixing height.......Inversion breaking between 0800 and 0900 hours, 
                    with mixing height around 5000 ft AGL by 1100 hours.
                    Mixing heights increasing to around 6500 ft AGL in 
                    the afternoon. 
Transport winds.....Northwest 10 to 15 mph in the morning becoming 
                    west 12 to 17 mph in the afternoon. 
Ventilation Index...High (547) increasing to very high (887) in the 
                    afternoon.


.WEDNESDAY NIGHT...

Sky/weather.........Partly cloudy. 
CWR.................0 percent. 
Chance of lightning.0 percent. 
Min temperature.....61-53, coolest on the ridgetops.
Max humidity........44 to 54 percent. 
Wind (20 ft)........West winds 6 to 17 mph becoming light 3 to 7 mph
                    overnight. Gusts up to 30 mph in the evening. 
Mixing height.......4000 ft AGL falling to 500 ft AGL. 
Transport winds.....West 10 to 16 mph. 
Ventilation Index...High (629) decreasing to low (45) overnight. 

.THURSDAY...

Sky/weather.........Sunny. 
CWR.................0 percent. 
Chance of lightning.0 percent. 
Max temperature.....82-93, hottest in the valley.
Min humidity........19 to 24 percent. 
Wind (20 ft)........West winds 7 to 15 mph. Gusts to 25mph in the 
                    afternoon.
Mixing height.......4000 ft AGL increasing to 7000 ft AGL in the 
                    afternoon. 
Transport winds.....West 9 to 13 mph. 
Ventilation Index...Moderate (282) increasing to very high (843) in 
                    the afternoon. 

$$
Forecaster...PP
Requested by...David Winter
Type of request...WILDFIRE
.TAG 2616935.0/OTX
.DELDT 07/07/26
.FormatterVersion 2.0.0
.EMAIL david_winter@firenet.gov