657
FNUS76 KPDT 090713
FWSPDT
SPOT FORECAST FOR COUGAR FIRE...BLM
NATIONAL WEATHER SERVICE PENDLETON OR
1213 AM PDT SAT AUG 9 2025
FORECAST IS BASED ON FORECAST START TIME OF 0600 PDT ON AUGUST 09.
***THUNDERSTORMS IMPLY GUSTY AND ERRATIC WINDS***
***WINDS ARE 20 FOOT 10-MINUTE AVERAGES***
***CWR-CHANCE OF WETTING RAIN 0.10 OR GREATER***
***VENTILATION INDEX IS DERIVED FROM THE
TRANSPORT WIND MULTIPLIED BY THE MIXING
HEIGHT IN 100'S OF FEET. INDEX CATEGORIES
ARE A GENERALIZED INDICATOR ONLY.***
IF YOU HAVE QUESTIONS OR CONCERNS WITH THIS FORECAST, PLEASE
CONTACT OUR OFFICE AT (541) 276-8134.
DISCUSSION
MODERATE (50-55%) OVERNIGHT HUMIDITIES OVER THE FIRE
AREA THIS MORNING, AS A WEAK INVERSION BREAKS UP AROUND 9 AM.
LIGHT WINDS THROUGH MUCH OF THE DAY, BUT A PRESSURE GRADIENT WILL
DEVELOP ACROSS THE CASCADES BY LATE AFTERNOON TO ELEVATE WINDS
BETWEEN 5 PM AND 10 PM. AN OFFSHORE HIGH PRESSURE RIDGE WILL
BUILD, CLEARING SKIES LATE TODAY INTO SUNDAY AND INCREASING
TEMPERATURES WHILE DECREASING HUMIDITIES. AN INVERSION IS EXPECTED
TO BEGIN TO DEVELOP AFTER 8 PM SATURDAY, LIKELY STICKING AROUND
UNTIL 10-11 AM SUNDAY.
SATURDAY
SKY/WEATHER.........PARTLY SUNNY (45-55 PERCENT).
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.0 PERCENT.
MAX TEMPERATURE.....83-86.
MIN HUMIDITY........13-17 PERCENT.
WIND (20 FT)........LIGHT NORTHWEST WINDS 2 TO 4 MPH BECOMING
NORTH 5 TO 10 MPH WITH GUSTS UP TO 18 MPH
AFTER 2 PM, PEAKING AFTER 5 PM.
MIXING HEIGHT.......7000 FT AGL.
TRANSPORT WINDS.....NORTH 5 TO 10 MPH.
VENTILATION INDEX...POOR (70) INCREASING TO FAIR (360) IN THE
AFTERNOON.
TIME (PDT) 6AM 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM
CHC OF LTNG (%).0 0 0 0 0 0 0 0 0 0 0 0
TEMP............47 51 58 64 69 73 76 78 80 82 84 85
RH..............57 50 41 33 28 23 21 19 17 15 16 16
20 FT WIND DIR..N N N N N N N N N N N N
20 FT WIND SPD..2 1 1 2 3 3 4 5 5 7 7 8
20 FT WIND GUST. 5 5 7 8 8 9 10 13
SATURDAY NIGHT
SKY/WEATHER.........PARTLY CLOUDY (20-30 PERCENT).
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.0 PERCENT.
MIN TEMPERATURE.....49-53.
MAX HUMIDITY........55-60 PERCENT.
WIND (20 FT)........NORTH WINDS 5 TO 10 MPH WITH GUSTS UP TO 18
MPH PEAKING BEFORE 10 PM AND BECOMING 3 TO 6
MPH AFTER 1 AM.
MIXING HEIGHT.......600 FT AGL.
TRANSPORT WINDS.....NORTH 6 TO 15 MPH.
VENTILATION INDEX...FAIR (430) DECREASING TO POOR (60) OVERNIGHT.
SUNDAY
SKY/WEATHER.........SUNNY (5-15 PERCENT).
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.0 PERCENT.
MAX TEMPERATURE.....89-93.
MIN HUMIDITY........11-16 PERCENT.
WIND (20 FT)........LIGHT NORTH WINDS 2 TO 5 MPH BECOMING 5 TO
9 MPH WITH GUSTS UP TO 14 MPH AFTER 2 PM.
WINDS PEAK BETWEEN 4 PM AND 7 PM.
MIXING HEIGHT.......6900 FT AGL.
TRANSPORT WINDS.....NORTHEAST 5 TO 8 MPH.
VENTILATION INDEX...POOR (50) INCREASING TO FAIR (280) IN THE
AFTERNOON.
FORECASTER...CALLIHAN
REQUESTED BY...MATT NOSS
TYPE OF REQUEST...WILDFIRE
.TAG 2519594.0/PDT
.DELDT 08/09/25
.FORMATTERVERSION 2.0.0
.EMAIL MNOSS@BLM.GOV
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page