687
FNUS76 KOTX 140224
FWSOTX

Spot Forecast for Marble Fire...BLM
National Weather Service Spokane WA
724 PM PDT Thu Aug 13 2026

Forecast is based on forecast start time of 0600 PDT on August 14.
.DISCUSSION...

Discussion:
Expect gradually warming conditions over the next few days. While
showers and thunderstorms can`t be completely ruled out for
Friday, occurrence at the fire location is unlikely. If a shower
were to develop in the vicinity, gusty and erratic winds would be
expected.


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).
***************************************************************


.FRIDAY...
Sky/weather.........Partly cloudy.
CWR.................5 percent.
Chance of lightning.5 percent.
Max temperature.....Around 70.
Min humidity........Near 44 percent.
Wind (20 ft)........North-northeast winds 5 to 7 mph.
Mixing height.......4000 ft AGL increasing to 7500 ft AGL in the
                    afternoon.
Transport winds.....Northeast around 7 mph.
Ventilation Index...Moderate (274).


.FRIDAY NIGHT...
Sky/weather.........Partly cloudy.
CWR.................0 percent.
Chance of lightning.0 percent.
Min temperature.....Around 57.
Max humidity........Near 70 percent.
Wind (20 ft)........Light winds, primarily downslope/downvalley
                    up to 4 mph.
Mixing height.......6500 ft AGL falling to 500 ft AGL.
Transport winds.....Light winds becoming northeast around 5 mph
                    overnight.
Ventilation Index...Low (189).


.SATURDAY...
Sky/weather.........Mostly sunny.
CWR.................0 percent.
Chance of lightning.0 percent.
Max temperature.....Around 74.
Min humidity........Near 37 percent.
Wind (20 ft)........Light and variable winds.
Mixing height.......5500 ft AGL increasing to 10000 ft AGL in the
                    afternoon.
Transport winds.....East around 5 mph shifting to the southwest
                    around 9 mph in the afternoon.
Ventilation Index...Moderate (216) increasing to very high (856) in
                    the afternoon.

$$

Forecaster...KD
Requested by...William Chapman
Type of request...WILDFIRE
.TAG 2619664.0/OTX
.DELDT 08/13/26
.FormatterVersion 2.0.0
.EMAIL wblakechapman@gmail.com,ian_schlake@fws.gov