303
FNUS76 KOTX 221257
FWSOTX
SPOT FORECAST FOR PTARMIGAN...USFS
NATIONAL WEATHER SERVICE SPOKANE WA
557 AM PDT SAT AUG 22 2026
FORECAST IS BASED ON FORECAST START TIME OF 0600 PDT ON AUGUST 22.
...RED FLAG WARNING IN EFFECT FROM 11 AM THIS MORNING TO 8 AM PDT
SUNDAY...
DISCUSSION
WINDS WILL INCREASE OUT OF THE SOUTH TODAY AHEAD OF A COLD FRONT
PASSAGE, SHIFTING TO WEST 1700 TO 1900 WITH FRONT PASSAGE. INCREASED
INSTABILITY WILL LEAD TO SHOWERS DEVELOPING, WITH A 40 PERCENT
CHANCE OF THUNDERSTORMS. RAIN AMOUNTS BETWEEN 0.10 AND 0.20 IS
FORECAST FOR THE FIRE. WIND GUSTS UP TO 25 MPH IS EXPECTED WITH THE
COLD FRONT, BUT BRIEF STRONGER GUSTS UP TO 40 MPH IS POSSIBLE NEAR
THUNDERSTORMS.
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).
***************************************************************
TODAY
SKY/WEATHER.........PARTLY SUNNY. 30 PERCENT CHANCE OF SHOWERS IN
THE MORNING INCREASING TO 70 PERCENT AFTER 1400.
15 PERCENT CHANCE OF THUNDERSTORMS IN THE MORNING
MORNING INCREASING TO A 40 PERCENT IN THE
AFTERNOON.
CWR.................60 PERCENT.
CHANCE OF LIGHTNING.10 PERCENT IN THE EARLY MORNING INCREASING TO 40
PERCENT AFTER 1200.
MAX TEMPERATURE.....62-73.
MIN HUMIDITY........35-45 PERCENT.
WIND (20 FT)........VARIABLE 1-4 MPH IN THE MORNING BECOMING
SOUTH-SOUTHWEST 8-11 MPH WITH RIDGETOP WINDS
15-20 MPH NEAR 1200. GUSTY AND ERRATIC WINDS
EXPECTED NEAR THUNDERSTORMS IN THE AFTERNOON.
MIXING HEIGHT.......INVERSION LIFTING AROUND 0900. MIXING HEIGHT
INCREASING TO 4000 FT AGL IN THE AFTERNOON.
TRANSPORT WINDS.....SOUTHEAST 5-10 MPH IN THE MORNING SHIFTING TO
THE SOUTHWEST 15-20 MPH IN THE AFTERNOON.
VENTILATION INDEX...HIGH (775).
TONIGHT
SKY/WEATHER.........MOSTLY CLOUDY. A 70 PERCENT CHANCE OF RAIN SHOWERS
AND 40 PERCENT CHANCE OF THUNDERSTORMS IN THE EVENING
THEN A 20 PERCENT CHANCE OF RAIN SHOWERS
OVERNIGHT.
CWR.................45 PERCENT.
CHANCE OF LIGHTNING.40 PERCENT.
MIN TEMPERATURE.....42-47.
MAX HUMIDITY........91-100 PERCENT.
WIND (20 FT)........WEST WINDS 5 TO 11 MPH. GUSTY AND ERRATIC WINDS
EXPECTED NEAR THUNDERSTORMS IN THE EVENING.
MIXING HEIGHT.......500 FT AGL.
TRANSPORT WINDS.....WEST AROUND 10 MPH.
VENTILATION INDEX...LOW (132).
SUNDAY
SKY/WEATHER.........MOSTLY CLOUDY. A 30 PERCENT CHANCE OF RAIN SHOWERS.
CWR.................5 PERCENT.
CHANCE OF LIGHTNING.10 PERCENT.
MAX TEMPERATURE.....50-60.
MIN HUMIDITY........60-70 PERCENT.
WIND (20 FT)........WEST WINDS 5 TO 10 MPH.
MIXING HEIGHT.......NEAR SURFACE THROUGH 0800 INCREASING TO 3000 FT AGL
IN THE AFTERNOON.
TRANSPORT WINDS.....WEST AROUND 10 MPH.
VENTILATION INDEX...MODERATE (384).
FORECASTER...JW
REQUESTED BY...BRIAN CAMPBELL
TYPE OF REQUEST...WILDFIRE
.TAG 2620029.2/OTX
.DELDT 08/22/26
.FORMATTERVERSION 2.0.0
.EMAIL BRIAN.D.CAMPBELL@USDA.GOV,WILLIAM.BURKS4@USDA.GOV,MICHAEL.BARAJAS@USDA.GOV
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