751
FNUS76 KPDT 082030
FWSPDT
SPOT FORECAST FOR BLACK ROCK FIRE...COIMT3
NATIONAL WEATHER SERVICE PENDLETON OR
130 PM PDT MON SEP 8 2025
FORECAST IS BASED ON FORECAST START TIME OF 1600 PDT ON SEPTEMBER 08.
***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
COOLER TEMPERATURES ARE EXPECTED THE NEXT SEVERAL DAYS.
SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON AND AGAIN
ON TUESDAY.
WITH THE INCREASE IN MOISTURE AND LOWER TEMPERATURES, RH VALUES WILL RISE AS
WELL. MIN RH VALUES WILL BE 30 TO 35 PERCENT TODAY AND 40 TO O45 PERCENT ON
TUESDAY WITH GOOD TO EXCELLENT OVERNIGHT RECOVERIES.
TODAY
SKY/WEATHER.........PARTLY SUNNY (55-65 PERCENT) THEN BECOMING
CLOUDY (85-95 PERCENT). CHANCE OF SHOWERS (40%)
IN THE AFTERNOON INCREASING TO 70% BY EVENING.
SLIGHT CHANCE OF THUNDERSTORMS (20%) IN THE AFTERNOON.
CWR.................8 PERCENT INCREASING TO 45 PERCENT LATE IN THE
AFTERNOON.
CHANCE OF LIGHTNING.30 PERCENT.
MAX TEMPERATURE.....81-84.
MIN HUMIDITY........29-34 PERCENT.
WIND (20 FT)........NORTHWEST WINDS 5 TO 10 MPH. GUSTY AND ERRATIC
WINDS EXPECTED NEAR THUNDERSTORMS.
RIDGETOP WIND.......NORTH WIND 5 TO 10 MPH.
MIXING HEIGHT.......7400 FT AGL.
TRANSPORT WINDS.....NORTHEAST AROUND 9 MPH SHIFTING TO THE
NORTHWEST AROUND 16 MPH LATE IN THE AFTERNOON.
VENTILATION INDEX...
TIME (PDT) 4 PM 6 PM 8 PM 10 PM MIDNGT 2 AM
CHC OF LTNG (%).30 30 10 10 10 10
TEMP............84 80 73 69 66 64
RH..............34 43 54 61 65 65
20 FT WIND......N 8 NW 10 NW 8 NW 8 SW 8 S 7
20 FT WIND GUST.12 13 10 10 10 8
TONIGHT
SKY/WEATHER.........MOSTLY CLOUDY (70-80 PERCENT). SHOWERS (70%) AND
SLIGHT CHANCE (20%)OF THUNDERSTORMS EARLY IN THE
EVENING, DECREASING TO 40% BY MORNING.
CWR.................45 PERCENT DECREASING TO 4 PERCENT LATE IN THE
EVENING.
CHANCE OF LIGHTNING.30 PERCENT.
MIN TEMPERATURE.....60-63.
MAX HUMIDITY........68-73 PERCENT.
WIND (20 FT)........NORTHWEST WINDS 5 TO 10 MPH SHIFTING TO THE
SOUTH 5 TO 6 MPH EARLY IN THE MORNING. GUSTY
AND ERRATIC WINDS EXPECTED NEAR THUNDERSTORMS
EARLY IN THE EVENING.
RIDGETOP WIND.......NORTH WIND INCREASING TO 10 TO 15 MPH WITH GUSTS
20 TO 25 MPH AND BECOMING NORTHWEST LATE IN THE EVENING.
MIXING HEIGHT.......1900 FT AGL. DECREASING TO 10 MPH BY MORNING.
TRANSPORT WINDS.....NORTHWEST 10 TO 16 MPH SHIFTING TO THE WEST 6
TO 8 MPH LATE IN THE EVENING.
VENTILATION INDEX...FAIR (360) DECREASING TO POOR (130) OVERNIGHT.
TUESDAY
SKY/WEATHER.........PARTLY SUNNY (50-60 PERCENT). CHANCE (40%) OF SHOWERS
IN THE MORNING, THEN SHOWERS LIKELY (70%) AND SLIGHT
CHANCE (20%) OF THUNDERSTORMS IN THE AFTERNOON.
CWR.................7 PERCENT INCREASING TO 13 PERCENT LATE IN THE
AFTERNOON.
CHANCE OF LIGHTNING.22 PERCENT.
MAX TEMPERATURE.....80-83.
MIN HUMIDITY........40-45 PERCENT.
WIND (20 FT)........SOUTH WINDS 5 TO 7 MPH SHIFTING TO THE
NORTHWEST 5 TO 8 MPH LATE IN THE MORNING. GUSTY
AND ERRATIC WINDS EXPECTED NEAR THUNDERSTORMS
LATE IN THE AFTERNOON.
RIDGETOP WIND.......NORTHWEST WIND 5 TO 10 MPH BECOMING WEST IN THE
AFTERNOON.
MIXING HEIGHT.......6400 FT AGL.
TRANSPORT WINDS.....WEST 6 TO 7 MPH SHIFTING TO THE NORTHWEST
AROUND 9 MPH LATE IN THE AFTERNOON.
VENTILATION INDEX...POOR (130) INCREASING TO FAIR (320) IN THE
AFTERNOON.
FORECASTER...NIERENBERG
REQUESTED BY...KATHY REED
TYPE OF REQUEST...WILDFIRE
.TAG 2521423.4/PDT
.DELDT 09/08/25
.FORMATTERVERSION 2.0.0
.EMAIL KATHERINE.REED@USDA.GOV
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