951
FNUS76 KPDT 120326
FWSPDT
SPOT FORECAST FOR BLACK ROCK FIRE...COIMT3
NATIONAL WEATHER SERVICE PENDLETON OR
826 PM PDT THU SEP 11 2025
FORECAST IS BASED ON FORECAST START TIME OF 0600 PDT ON SEPTEMBER 12.
***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
WARMER, DRIER WEATHER IS FORECAST FRIDAY THROUGH SATURDAY
AS A BRIEF RIDGE OF HIGH PRESSURE BUILDS OVER THE PACIFIC NORTHWEST.
CHANCES OF SHOWERS AND THUNDERSTORMS ARE VERY LOW (<5%) WITH ANY
ACTIVITY EXPECTED OVER THE BLUE MOUNTAINS. MINIMUM RHS ARE ANTICIPATED TO
FALL SATURDAY AFTERNOON. SHOWER AND THUNDERSTORM CHANCES THEN RETURN
SATURDAY NIGHT AND SUNDAY AS A LOW-PRESSURE SYSTEM IS LIKELY
(>80% CONFIDENCE) TO MOVE ONSHORE.
FRIDAY
SKY/WEATHER.........MOSTLY SUNNY (5-20 PERCENT).
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.2 PERCENT.
MAX TEMPERATURE.....78-81.
MIN HUMIDITY........32-37 PERCENT.
WIND (20 FT)........SOUTHWEST WINDS 5-8 MPH SHIFTING TO THE
NORTHWEST LATE IN THE AFTERNOON.
RIDGETOP WIND.......SOUTHWEST WINDS 5-8 MPH SHIFTING TO THE
NORTHWEST LATE IN THE AFTERNOON. GUSTS UP
TO 15 MPH.
MIXING HEIGHT.......INCREASING TO 5000-5500 FT AGL BY AFTERNOON.
TRANSPORT WINDS.....SOUTHWEST 5-7 MPH SHIFTING TO THE
NORTHWEST LATE IN THE AFTERNOON.
VENTILATION INDEX...POOR (70) INCREASING TO FAIR (200) IN THE
AFTERNOON.
TIME (PDT) 6 AM 8 AM 10 AM NOON 2 PM 4 PM
CHC OF LTNG (%).0 0 0 0 0 0
TEMP............54 57 63 71 76 79
RH..............81 77 68 54 43 39
20 FT WIND......S 7 S 8 S 8 SW 8 W 7 W 7
20 FT WIND GUST.8 10 10 10 10 10
FRIDAY NIGHT
SKY/WEATHER.........MOSTLY CLEAR (10-20 PERCENT).
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.0 PERCENT.
MIN TEMPERATURE.....57-60.
MAX HUMIDITY........63-68 PERCENT.
WIND (20 FT)........NORTHWEST WINDS 4-8 MPH SHIFTING TO THE
SOUTHWEST OVERNIGHT.
RIDGETOP WIND.......NORTHWEST WINDS 5-9 MPH SHIFTING TO THE
SOUTHWEST OVERNIGHT. GUSTS UP TO 15 MPH.
MIXING HEIGHT.......DECREASING TO 500-800 FT AGL OVERNIGHT.
TRANSPORT WINDS.....NORTH 5-7 MPH SHIFTING TO THE SOUTHWEST
5-7 MPH OVERNIGHT.
VENTILATION INDEX...POOR (140) DECREASING TO POOR (30) OVERNIGHT.
SATURDAY
SKY/WEATHER.........MOSTLY SUNNY (5-20 PERCENT).
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.3 PERCENT.
MAX TEMPERATURE.....82-85.
MIN HUMIDITY........23-28 PERCENT.
WIND (20 FT)........SOUTH WINDS 4-8 MPH SHIFTING TO THE WEST
TO NORTHWEST LATE IN THE AFTERNOON.
RIDGETOP WIND.......SOUTH WINDS 5-9 MPH SHIFTING TO THE WEST
TO NORTHWEST LATE IN THE AFTERNOON.
MIXING HEIGHT.......INCREASING TO 7400 FT AGL.
TRANSPORT WINDS.....SOUTHWEST 5-7 MPH SHIFTING TO THE WEST
TO NORTHWEST 6-8 MPH LATE IN THE AFTERNOON.
VENTILATION INDEX...POOR (40) INCREASING TO FAIR (250) IN THE
AFTERNOON.
FORECASTER...PLUNKETT
REQUESTED BY...KATHY REED
TYPE OF REQUEST...WILDFIRE
.TAG 2521848.0/PDT
.DELDT 09/11/25
.FORMATTERVERSION 2.0.0
.EMAIL KATHERINE.REED@USDA.GOV
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