355
FNUS76 KPDT 082053
FWSPDT
SPOT FORECAST FOR BLACK ROCK FIRE...COIMT3
NATIONAL WEATHER SERVICE PENDLETON OR
153 PM PDT MON SEP 8 2025
FORECAST IS BASED ON FORECAST START TIME OF 0600 PDT ON SEPTEMBER 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
COOLER TEMPERATURES ARE EXPECTED THE NEXT SEVERAL DAYS.
SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED ON TUESDAY, WITH MORE
WIDESPREAD SHOWERS AND ISOLATED THUNDERSTORMS ON WEDNESDAY.
WITH THE INCREASE IN MOISTURE AND LOWER TEMPERATURES, RH VALUES WILL RISE AS
WELL. MIN RH VALUES WILL BE 40 TO 45 PERCENT TUESDAY AND 45 TO 50 PERCENT
ON WEDNESDAY WITH EXCELLENT OVERNIGHT RECOVERIES.
TUESDAY
SKY/WEATHER.........PARTLY SUNNY (50-60 PERCENT). CHANCE (40%) OF SHOWERS
IN THE MORNING, THEN SHOWERS LIKELY (70%) AND SLIGHT
CHANCE OF THUNDERSTORMS (20%) 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.
TIME (PDT) 6 AM 8 AM 10 AM NOON 2 PM 4 PM
CHC OF LTNG (%).0 0 0 10 20 20
TEMP............60 63 70 75 77 78
RH..............78 70 57 51 48 45
20 FT WIND......S 6 SW 6 SW 6 NW 6 NW 7 NW 7
20 FT WIND GUST. 8 10 10
TUESDAY NIGHT
SKY/WEATHER.........PARTLY CLOUDY (40-50 PERCENT), THEN BECOMING
MOSTLY CLOUDY (55-60 PERCENT). SLIGHT CHANCE (20%) OF
THUNDERSTORMS EARLY IN THE EVENING. CHANCE OF
SHOWERS (40%) IN THE EVENING, THEN SLIGHT CHANCE 20%)
OF SHOWERS EARLY IN THE MORNING.
CWR.................13 PERCENT DECREASING TO 0 PERCENT LATE IN THE
EVENING.
CHANCE OF LIGHTNING.15 PERCENT.
MIN TEMPERATURE.....AROUND 60.
MAX HUMIDITY........71-76 PERCENT.
WIND (20 FT)........NORTHWEST WINDS 5 TO 8 MPH SHIFTING TO THE
SOUTHWEST OVERNIGHT. GUSTY AND ERRATIC WINDS
EXPECTED NEAR THUNDERSTORMS EARLY IN THE
EVENING.
RIDGETOP WIND.......NORTHWEST WIND 5 TO 10 MPH.
MIXING HEIGHT.......1900 FT AGL.
TRANSPORT WINDS.....NORTHWEST 6 TO 9 MPH SHIFTING TO THE WEST
AROUND 6 MPH OVERNIGHT.
VENTILATION INDEX...FAIR (290) DECREASING TO POOR (100) OVERNIGHT.
WEDNESDAY
SKY/WEATHER.........PARTLY SUNNY (60-70 PERCENT). SLIGHT CHANCE OF
SHOWERS (20%) IN THE MORNING, THEN CHANCE (50%)
OF SHOWERS. SLIGHT CHANCE (20%) OF THUNDERSTORMS IN THE
AFTERNOON
CWR.................0 PERCENT INCREASING TO 17 PERCENT LATE IN THE
MORNING.
CHANCE OF LIGHTNING.18 PERCENT.
MAX TEMPERATURE.....AROUND 80.
MIN HUMIDITY........45-50 PERCENT.
WIND (20 FT)........SOUTHWEST WINDS 5 TO 8 MPH SHIFTING TO THE
NORTHWEST LATE IN THE MORNING. GUSTY AND
ERRATIC WINDS EXPECTED NEAR THUNDERSTORMS LATE
IN THE AFTERNOON.
RIDGETOP WIND.......NORTHWEST TO NORTH WINDS AROUND 10 MPH.
MIXING HEIGHT.......6200 FT AGL.
TRANSPORT WINDS.....SOUTHWEST 5 TO 6 MPH SHIFTING TO THE NORTHWEST
6 TO 9 MPH LATE IN THE MORNING.
VENTILATION INDEX...POOR (100) INCREASING TO FAIR (340) 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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