129
FNUS76 KOTX 310041
FWSOTX
SPOT FORECAST FOR SILVER FIRE...USFS
NATIONAL WEATHER SERVICE SPOKANE WA
541 PM PDT SUN AUG 30 2026
FORECAST IS BASED ON FORECAST START TIME OF 1800 PDT ON AUGUST 30.
DISCUSSION
WESTERLY WINDS WILL DECREASE TONIGHT BECOMING LIGHTER AND TERRAIN
DRIVEN UNDER A BUILDING RIDGE OF HIGHER PRESSURE ON MONDAY.
TEMPERATURES WILL ALSO WARM UP SIGNIFICANTLY WITH TUESDAY BEING
BACK ABOVE NORMAL. DRIER CONDITIONS THROUGH TUESDAY AS WELL AND
THERMAL BELTS DEVELOPING. WEATHER CONDITIONS TURN ACTIVE AGAIN
AROUND TUESDAY NIGHT INTO MID WEEK. THERE WILL BE A 10-20 PERCENT
CHANCE FOR THUNDERSTORMS TUESDAY EVENING INTO TUESDAY NIGHT
INCREASING TO A 30 PERCENT CHANCE ON WEDNESDAY. SHOWERS AND
THUNDERSTORMS WILL BRING DOWNPOURS WITH A 60 PERCENT CHANCE FOR
A WETTING RAIN. ANOTHER SHOT WITH A 50-70 PERCENT CHANCE OF
WETTING RAINS EXPECTED WEDNESDAY NIGHT INTO THURSDAY. TOTAL RAINFALL
BETWEEN WEDNESDAY THROUGH THURSDAY OF BETWEEN 0.25 AND 0.75 INCHES
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).
***************************************************************
TONIGHT
SKY/WEATHER.........PARTLY CLOUDY IN THE EVENING THEN CLEARING
AFTER 2200 HOURS.
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.0 PERCENT.
MIN TEMPERATURE.....RIDGETOP (AT 7000 FT)........42.
MIDSLOPE (AT 5500 FT)........48.
VALLEY BOTTOM (AT 3600 FT)...44.
MAX HUMIDITY........64-76 PERCENT.
WIND (20 FT)........RIDGETOPS...SOUTHWEST WINDS 7 TO 10 MPH
WITH GUSTS UP TO 15 TO 18 MPH BECOMING
WEST-NORTHWEST 4 TO 7 MPH AFTER 2000 HOURS.
MIDSLOPE/VALLEY...SOUTHWEST WINDS 4 TO
7 MPH IN THE EVENING BECOMING DOWNSLOPE-
DOWNVALLEY 2 TO 5 MPH AFTER 2000 HOURS.
MIXING HEIGHT.......3000 FT AGL FALLING TO 800 FT AGL AFTER
2000 HOURS.
TRANSPORT WINDS.....WEST-SOUTHWEST 5 TO 9 MPH.
VENTILATION INDEX...HIGH (567) DECREASING TO LOW (29) OVERNIGHT.
MONDAY
SKY/WEATHER.........SUNNY.
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.0 PERCENT.
MAX TEMPERATURE.....RIDGETOP (AT 7000 FT)........54.
MIDSLOPE (AT 5500 FT)........61.
VALLEY BOTTOM (AT 3600 FT)...72.
MIN HUMIDITY........RIDGETOP (AT 7000 FT)........51-55 PERCENT.
MIDSLOPE (AT 5500 FT)........43-47 PERCENT.
VALLEY BOTTOM (AT 3600 FT)...30-34 PERCENT.
WIND (20 FT)........RIDGETOPS...SOUTH WINDS 5 TO 8 MPH.
MIDSLOPE/VALLEY...SOUTH-SOUTHEAST WINDS
2 TO 5 MPH.
MIXING HEIGHT.......INVERSION LIFTS AROUND 1000 HOURS. MIXING
HEIGHT INCREASING TO 3300 FT AGL BY 1500
HOURS.
TRANSPORT WINDS.....SOUTH-SOUTHWEST AROUND 7 MPH.
VENTILATION INDEX...LOW (173) INCREASING TO MODERATE (349) IN THE
AFTERNOON.
MONDAY NIGHT
SKY/WEATHER.........CLEAR IN THE EVENING BECOMING PARTLY CLOUDY
OVERNIGHT.
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.0 PERCENT.
MIN TEMPERATURE.....RIDGETOP (AT 7000 FT)........48.
MIDSLOPE (AT 5500 FT)........52.
VALLEY BOTTOM (AT 3600 FT)...45.
MAX HUMIDITY........RIDGETOP/MIDSLOPE...57-63 PERCENT.
VALLEY BOTTOM.......84-88 PERCENT.
WIND (20 FT)........RIDGETOPS...SOUTH WINDS 4 TO 7 MPH EARLY IN
THE EVENING SWITCHING EAST-NORTHEAST 3 TO
6 MPH AFTER 1900 HOURS.
MIDSLOPE/VALLEY...SOUTH-SOUTHEAST WINDS
2 TO 5 MPH.
MIXING HEIGHT.......2500 FT AGL FALLING TO NEAR SURFACE AFTER
2000 HOURS.
TRANSPORT WINDS.....SOUTHWEST AROUND 6 MPH SHIFTING TO THE
EAST OVERNIGHT.
VENTILATION INDEX...LOW (134).
TUESDAY
SKY/WEATHER.........PARTLY SUNNY.
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.0 PERCENT.
MAX TEMPERATURE.....RIDGETOP (AT 7000 FT)........62.
MIDSLOPE (AT 5500 FT)........70.
VALLEY BOTTOM (AT 3600 FT)...81.
MIN HUMIDITY........RIDGETOP (AT 7000 FT)........31-35 PERCENT.
MIDSLOPE (AT 5500 FT)........26-30 PERCENT.
VALLEY BOTTOM (AT 3600 FT)...21-25 PERCENT.
WIND (20 FT)........SOUTHEAST WINDS 3 TO 7 MPH.
MIXING HEIGHT.......INCREASING TO 5500 FT AGL IN THE AFTERNOON.
TRANSPORT WINDS.....SOUTHEAST 7 TO 10 MPH.
VENTILATION INDEX...LOW (176) INCREASING TO HIGH (713) IN THE
AFTERNOON.
FORECASTER...SVH
REQUESTED BY...BRUCE GIERSDORF
TYPE OF REQUEST...WILDFIRE
.TAG 2620738.2/OTX
.DELDT 08/30/26
.FORMATTERVERSION 2.0.0
.EMAIL BGIERSDORF@YAHOO.COM
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page