391
FNUS76 KOTX 121517
FWSOTX

Spot Forecast for porcupine fire...usfs
National Weather Service Spokane WA
817 AM PDT Wed Aug 12 2026

Forecast is based on forecast start time of 0800 PDT on August 12.

..RED FLAG WARNING IN EFFECT FROM 11 AM THIS MORNING TO 11 PM
PDT THIS EVENING...

.DISCUSSION...

An abrupt wind shift with gusty northeast winds are expected to develop
over the fire area near 1800 PDT this evening as a strong backdoor
cold front sweeps through the area. This will bring gusts up to 30 mph
except up to 40 mph if thunderstorms develops near the area which
carries a 30 percent chance.  Then as a weather system moves across
the area the chances for rain increase to 50 percent Wednesday Night,
and 60 percent on Thursday.

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

.REST OF TODAY...

Sky/weather.........Hazy. Partly cloudy. A 10 percent chance of a
                    shower or thunderstorm after 1600 PDT.
CWR.................5 percent.
Chance of lightning.10 percent.
Max temperature.....76-79.
Min humidity........37-43 percent.
Wind (20 ft)........Northeast 3 to 6 mph. Gusty and erratic winds
                    expected near thunderstorms late in the afternoon.
Mixing height.......Rising to 6500 ft AGL in the afternoon.
Transport winds.....Light winds becoming southwest around 5 mph in
                    the afternoon.
Ventilation Index...Moderate (201) increasing to moderate (396) in
                    the afternoon.

.TONIGHT...

...Gusty northeast winds developing near 1800 PDT...

Sky/weather.........Mostly cloudy. Haze in the evening. A 30 percent
                    chance of showers and thunderstorms in the evening, then
                    a 50 percent chance of rain showers and a 20 percent
                    chance of thunderstorms overnight.
CWR.................20 percent.
Chance of lightning.30 percent.
Min temperature.....Around 53.
Max humidity........96 percent.
Wind (20 ft)........Northeast winds 10 to 17 mph with gusts up to 30 mph
                    1800 to 2200 PDT with thunderstorm outflow gusts up
                    to 40 mph, then decreasing to 4 to 9 mph.
Mixing height.......1500 ft AGL falling to 500 ft AGL by 2200 PDT.
Transport winds.....Northeast 15 to 25 mph 1800 to 2200 PDT then decreasing
                    to 10 mph.
Ventilation Index...Moderate (305) decreasing to low (56)
                    overnight.

.THURSDAY...

Sky/weather.........Mostly cloudy. Slight chance of thunderstorms
                    in the morning. Rain showers likely through the
                    day. Chance of thunderstorms in the afternoon.
CWR.................50 percent.
Chance of lightning.25 percent.
Max temperature.....67-70.
Min humidity........50-55 percent.
Wind (20 ft)........Northeast winds 5 to 10 mph. Gusty and erratic
                    winds expected near thunderstorms in the
                    morning. Gusty and erratic winds expected near
                    thunderstorms in the afternoon.
Mixing height.......Near surface through 0800 PDT increasing to 4500 ft
                    AGL in the afternoon.
Transport winds.....Northeast around 10 mph.
Ventilation Index...Moderate (202) increasing to moderate (366) in
                    the afternoon.

$$
Forecaster...JW
Requested by...cummings
Type of request...WILDFIRE
.TAG 2619525.0/OTX
.DELDT 08/12/26
.FormatterVersion 2.0.0
.EMAIL 208cummings@gmail.com