849
FNUS76 KPDT 042314
FWSPDT
SPOT FORECAST FOR GRASSHOPPER FIRE...WESTERN WASHINGTON TEAM 3
NATIONAL WEATHER SERVICE PENDLETON OR
414 PM PDT SUN OCT 4 2026
FORECAST IS BASED ON FORECAST START TIME OF 0700 PDT ON OCTOBER 05.
***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 TRANSPORT WIND
MULTIPLIED BY THE MIXING HEIGHT IN 100'S OF FT.
CATEGORIES ARE A GENERALIZED INDICATOR ONLY:
LOW (< 200), MODERATE (200-500), HIGH (500-700),
AND VERY HIGH (> 700). ***
IF YOU HAVE QUESTIONS OR CONCERNS WITH THIS FORECAST, PLEASE
CONTACT OUR OFFICE AT (541) 276-8134.
DISCUSSION
WARM, DRY CONDITIONS ACCOMPANIED BY DIURNALLY
AND TERRAIN-DRIVEN WINDS WILL PERSIST UNDER AN UPPER-LEVEL
RIDGE OF HIGH PRESSURE. THE RIDGE IS FORECAST TO REBUILD
THROUGH MIDDLE TO LATE THIS WEEK, KEEPING SIMILAR CONDITIONS
IN PLACE EACH DAY.
MONDAY
SKY/WEATHER.........SUNNY (5-25 PERCENT).
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.0 PERCENT.
MAX TEMPERATURE.....84-87.
MIN HUMIDITY........15-20 PERCENT.
WIND (20 FT)........DRAINAGE WINDS 1-3 MPH EARLY MORNING, BECOMING
UPSLOPE THEN UPVALLEY WINDS 1-5 MPH MID-MORNING.
RIDGETOP WIND.......DRAINAGE WINDS 1-3 MPH EARLY MORNING, BECOMING
UPSLOPE THEN UPVALLEY WINDS 2-6 MPH MID-MORNING.
MIXING HEIGHT.......INCREASING TO 3900-4400 FT AGL BY EARLY AFTERNOON.
TRANSPORT WINDS.....NORTHWEST 4-8 MPH.
VENTILATION INDEX...LOW (30) INCREASING TO LOW TO MODERATE
(130-200) IN THE AFTERNOON.
TIME (PDT) 7AM 8AM 9AM 10A 11A 12P 1PM 2PM 3PM 4PM 5PM 6PM
CHC OF LTNG (%).0 0 0 0 0 0 0 0 0 0 0 0
TEMP............53 55 60 69 75 79 82 84 84 84 82 78
RH..............56 56 48 36 30 26 22 20 18 18 19 23
20 FT WIND DIR..W W W S E E NE NE NE NE N N
20 FT WIND SPD..3 4 3 2 2 2 3 3 4 5 5 5
20 FT WIND GUST. 10 10 10
MONDAY NIGHT
SKY/WEATHER.........MOSTLY CLEAR (20-35 PERCENT).
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.0 PERCENT.
MIN TEMPERATURE.....49-54.
MAX HUMIDITY........48-60 PERCENT.
WIND (20 FT)........BECOMING DRAINAGE WINDS 1-4 MPH LATE EVENING
AND OVERNIGHT.
RIDGETOP WIND.......BECOMING DRAINAGE WINDS 1-4 MPH LATE EVENING
AND OVERNIGHT.
MIXING HEIGHT.......DECREASING TO 200-500 FT AGL OVERNIGHT.
TRANSPORT WINDS.....WEST 4-8 MPH.
VENTILATION INDEX...DECREASING TO LOW (30) OVERNIGHT.
TUESDAY
SKY/WEATHER.........SUNNY (5-15 PERCENT).
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.0 PERCENT.
MAX TEMPERATURE.....80-83.
MIN HUMIDITY........19-24 PERCENT.
WIND (20 FT)........DRAINAGE WINDS 1-4 MPH EARLY MORNING, BECOMING
UPSLOPE THEN UPVALLEY WINDS 1-5 MPH BY MID-MORNING.
RIDGETOP WIND.......DRAINAGE WINDS 1-4 MPH EARLY MORNING, BECOMING
UPSLOPE THEN UPVALLEY WINDS 2-6 MPH BY MID-MORNING.
MIXING HEIGHT.......INCREASING TO 2600-3100 FT AGL BY EARLY AFTERNOON.
TRANSPORT WINDS.....WEST TO SOUTHWEST 3-6 MPH EARLY MORNING, BECOMING
NORTHWEST TO NORTH 5-8 MPH LATE MORNING AND
AFTERNOON.
VENTILATION INDEX...LOW (30) INCREASING TO LOW (60-140) IN THE
AFTERNOON.
FORECASTER...PLUNKETT
REQUESTED BY...MATT KINNEE
TYPE OF REQUEST...WILDFIRE
.TAG 2622926.3/PDT
.DELDT 10/04/26
.FORMATTERVERSION 2.0.0
.EMAIL 2026.GRASSHOPPER.SITUATION@FIRENET.GOV,MATT_KINNEE@FIRENET.GOV
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