881
FXUS66 KPDT 311104
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
404 AM PDT MON AUG 31 2026
KEY MESSAGES
- DRYING AND WARMING TREND WILL CONTINUE THROUGH EARLY TUESDAY
AS UPPER LEVEL HIGH PRESSURE MOVES OVER THE REGION
- A SERIES OF UPPER LEVEL LOW PRESSURE SYSTEMS WILL BRING
PERIODS OF RAIN, BREEZY WESTERLY WINDS, AND ISOLATED
THUNDERSTORM CHANCES TUESDAY INTO FRIDAY
DISCUSSION
SHORT TERM UPPER RIDGING WILL INFLUENCE THE WEATHER ACROSS THE
REGION TODAY LEADING TO A DAY OF WARMER TEMPERATURES AND LOW
RELATIVE HUMIDITY AREA-WIDE. WIDESPREAD 80S ARE EXPECTED HIGHS
THIS AFTERNOON WITH COOLER 70S IN THE FOOTHILLS AND MOUNTAIN
ZONES. SURFACE HIGH PRESSURE WILL LEAD TO LIGHT NORTHEAST WINDS
ACROSS WA (SLIGHTLY BREEZY OVER THE OREGON COLUMBIA BASIN) AND
LIGHT SOUTH WINDS OVER THE THE JOHN DAY BASIN AND AREAS SOUTH.
HREF SHOWED UP TO ABOUT 250 J/JG MEAN MUCAPES ACROSS LIMITED
REACH OF THE EASTERN BLUE MOUNTAINS/WALLOWAS TUESDAY AFTERNOON
WITH LIMITED, LESS THAN 15% CHANCES FOR LIGHTNING BETWEEN ABOUT
18Z AND 23Z ESPECIALLY OVER WALLOWA CO.
CHANCES FOR WETTING RAINS ARE IN THE THE 60 TO 85% CONFIDENCE
RANGE FOR THE 24 HOURS ENDING 00Z THURSDAY ACROSS THE EASTERN
MOUNTAINS AND THE THE CASCADES EASTERN SLOPES. LOW END CWRS
INCREASE TO LIKELY (60% EVEN ACROSS THE COLUMBIA BASIN AND
HIGHER) AND MORESO ACROSS THE ENTIRE FORECAST AREA BY THE END
OF THE DAY THURSDAY. A LOOK AT EXPECTED 2 DAY COMBINED RAIN
(WED/THUR) LOOKS LIKE NEAR A WETTING RAIN OVER THE WA COLUMBIA
BASIN, TO NEAR A QUARTER INCH OF RAIN OVER THE FOOTHILLS OF THE
BLUES, CENTRAL OREGON...TO AS MUCH AS ONE HALF TO THREE QUARTERS
OF AN INCH OVER THE BLUE MOUNTIES AND ONE INCH OR MORE ALONG
THE CASCADE CREST.
AVIATION /12Z TAFS THROUGH 12Z TUESDAY/
CLEAR SKY OVER THE ENTIRE REGION WILL LEAD TO VFR CONDITIONS
WITH LIGHT WINDS UNDER 10 KNOTS. GUSTS TO AROUND 20 TO 25 KTS
WILL DEVELOP AT DLS AFTER MIDNIGHT AS A SYSTEM APPROACHES THE
REGION WITH SCATTERED TO BROKEN HIGH CLOUDS OVERNIGHT.
FIRE WEATHER
MINIMUM RH VALUES WILL RANGE FROM THE LOW 20S ACROSS THE
KITTITAS, YAKIMA VALLEYS AND THE CASCADE EAST SLOPES, AND AROUND
20 PERCENT AND LESS EVERY WHERE ELSE. MORE BREEZY WINDS ARE
EXPECTED TUESDAY THOUGH THE OREGON COLUMBIA BASIN AND THE
COLUMBIA RIVER GORGE/KITTITAS AND YAKIMA VALLEYS. NO
SIGNIFICANT AREAS OF COMBINED PROBABILITIES FOR RED FLAG
(CRITICAL LOW RH AND WIND) SHOWS UP IN THE FORECAST THIS WEEK.
CHANCES FOR WETTING RAINS INCREASE WEDNESDAY THROUGH THURSDAY.
PRELIMINARY POINT TEMPS/POPS
PDT 86 51 83 50 / 0 0 0 50
ALW 89 57 84 55 / 0 0 0 50
PSC 89 53 87 51 / 0 0 0 40
YKM 85 59 87 56 / 0 0 0 30
HRI 88 54 86 50 / 0 0 0 40
ELN 80 54 82 49 / 0 0 0 40
RDM 87 45 78 39 / 0 0 30 40
LGD 88 53 86 48 / 0 0 10 50
GCD 91 54 86 50 / 0 0 10 50
DLS 88 60 79 55 / 0 0 0 20
PDT WATCHES/WARNINGS/ADVISORIES
WA...NONE.
OR...AIR QUALITY ALERT UNTIL NOON PDT TODAY FOR ORZ041-505-506-
509>511.
DISCUSSION...71
AVIATION...71
FIRE WEATHER...71
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page