674
FNUS76 KPDT 070901
FWSPDT
SPOT FORECAST FOR SANDBOX 605 RX...USFS
NATIONAL WEATHER SERVICE PENDLETON OR
201 AM PDT TUE APR 7 2026
FORECAST IS BASED ON IGNITION TIME OF 1000 PDT ON APRIL 07.
***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
A LIGHT (UNDER 5 MPH) NORTHEAST TO NORTH
WIND WILL INCREASE TO AROUND 10 MPH BY 10 AM
AND THEN 10 TO 20 MPH WITH GUSTS TO 25 MPH BY
2 PM THIS AFTERNOON. STEEP LAPSE RATES WILL
DEVELOP QUICKLY THIS MORNING, INCREASING MIXING
HEIGHTS AND LEADING TO EXCELLENT VENTILATION
INDICES.
REST OF TODAY
SKY/WEATHER.........SUNNY (10-20 PERCENT).
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.0 PERCENT.
MAX TEMPERATURE.....59-62.
MIN HUMIDITY........28-33 PERCENT.
WIND (20 FT)........NORTHWEST WINDS 5 TO 19 MPH WITH GUSTS TO
AROUND 24 MPH.
RIDGETOP WIND.......NORTHWEST 15 TO 20 MPH.
MIXING HEIGHT.......NEAR THE SURFACE AT SUNRISE, INCREASING
TO 5500 FT AGL BY 11 AM.
TRANSPORT WINDS.....NORTHWEST 15 TO 23 MPH.
VENTILATION INDEX...EXCELLENT (1050) IN THE AFTERNOON.
TIME (PDT) 10 AM NOON 2 PM 4 PM 6 PM 8 PM
CHC OF LTNG (%).0 0 0 0 0 0
TEMP............52 57 59 57 54 48
RH..............46 40 35 34 34 37
20 FT WIND......NW 8 NW 12 NW 19 NW 19 NW 15 N 11
20 FT WIND GUST.11 18 24 24 23 18
TONIGHT
SKY/WEATHER.........MOSTLY CLEAR (5-15 PERCENT).
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.0 PERCENT.
MIN TEMPERATURE.....36-39.
MAX HUMIDITY........44-49 PERCENT.
WIND (20 FT)........NORTH WINDS 5 TO 15 MPH WITH GUSTS TO AROUND 23
MPH DECREASING TO 5 TO 6 MPH EARLY IN THE
MORNING.
RIDGETOP WIND.......NORTH WINDS 18 TO 25 MPH IN THE EVENING,
DROPPING TO 10 TO 15 MPH OVERNIGHT.
MIXING HEIGHT.......600 FT AGL.
TRANSPORT WINDS.....NORTH 15 TO 21 MPH DECREASING TO 6 TO 10 MPH
LATE IN THE EVENING.
VENTILATION INDEX...FAIR (270) DECREASING TO POOR (50) OVERNIGHT.
WEDNESDAY
SKY/WEATHER.........MOSTLY SUNNY (25-35 PERCENT).
CWR.................0 PERCENT.
CHANCE OF LIGHTNING.0 PERCENT.
MAX TEMPERATURE.....59-62.
MIN HUMIDITY........23-28 PERCENT.
WIND (20 FT)........NORTH WINDS 5 TO 7 MPH SHIFTING TO THE WEST 5
TO 8 MPH LATE IN THE MORNING, THEN SHIFTING TO
THE NORTHWEST 5 TO 7 MPH LATE IN THE AFTERNOON.
RIDGETOP WIND.......NORTHWEST 10 TO 15 MPH.
MIXING HEIGHT.......4700 FT AGL.
TRANSPORT WINDS.....NORTH 5 TO 6 MPH SHIFTING TO THE WEST 8 TO 10
MPH LATE IN THE MORNING.
VENTILATION INDEX...POOR (40) INCREASING TO FAIR (290) IN THE
AFTERNOON.
FORECASTER...RUSSELL
REQUESTED BY...RYAN MIDDLETON
TYPE OF REQUEST...PRESCRIBED
.TAG 2609228.0/PDT
.DELDT 04/07/26
.FORMATTERVERSION 2.0.0
.EMAIL RYAN.MIDDLETON@USDA.GOV
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