830
FXUS66 KPDT 172335
AFDPDT
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PENDLETON OR
435 PM PDT WED JUN 17 2026
KEY MESSAGES
- RED FLAG WARNINGS IN EFFECT THROUGH 9PM THIS EVENING FOR
KITTITAS AND YAKIMA VALLEY & CENTRAL MOUNTAINS OF OREGON.
- BREEZY WINDS TODAY AND DURING THE WEEKEND.
- WARMING TREND CONTINUES.
DISCUSSION
THE REGION WILL UNDERGO A MID LEVEL SYNOPTIC TRANSITION AS THE
SHORTWAVE ENERGY OVER NE WA SLIDES FURTHER INLAND AHEAD OF A
DEVELOPING BROADER AND WEAKER GEOPOTENTIAL HEIGHT FIELD FOR
THURSDAY AND FRIDAY. MODELS SHOW A COMPACT LOW SLIDING DOWN THE
BRITISH COLUMBIA COAST BY FRIDAY EVENING THAT WILL ENHANCE WINDS
ACROSS THE INTERIOR NW ON SATURDAY, TRACK IN TO THE SOUTHERN
CANADIAN PRAIRIE PROVINCES ON SUNDAY LEADING TO A RETURN TO
HOTTER TEMPERATURES AND HEATRISK LEVELS INCREASING MONDAY AND
TUESDAY OF NEXT WEEK.
HEATRISK IS FORECAST TO INCREASE TO A LEVEL 2 (ORANGE) ACROSS
THE LOWEST ELEVATIONS OF THE COLUMBIA BASIN AND RIVER GORGE
ZONES MONDAY AND EXPAND ON TUESDAY AFFECTING THE YAKIMA/KITTITAS
VALLEY AND MORE OF THE JOHN DAY BASIN. THIS PERIOD OF INCREASED
HEAT EARLY NEXT WEEK WILL ALSO BRING ABOUT A PERIOD OF
CONVECTIVE MONITORING ACROSS THE BLUE MOUNTAIN ZONE WHICH WOULD
BE A DRY LIGHTNING RISK. ZONES. PROBABILITY OF THUNDER IS NOT
HIGH, BUT AROUND 5% FOR THOSE EASTERN MOUNTAIN ZONES TUESDAY
EVENING.
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
VFR CONDITIONS ACCOMPANIED BY DIURNALLY AND TERRAIN-DRIVEN
WINDS ARE FORECAST FOR THE NEXT 24 HOURS. FEW-BKN MID/HIGH
CLOUD IS ANTICIPATED TO OVERSPREAD THE REGION FROM SOUTH TO
NORTH OVERNIGHT THROUGH THURSDAY.
FIRE WEATHER
RED FLAG WARNINGS REMAIN IN PLACE FOR THE BALANCE OF TODAY
THROUGH 11 PM THIS EVENING. 70-80% RISK THRESHOLD FOR GUSTS
ABOVE 20 MPH AND AND RELATIVE HUMIDITY BELOW 25% CREATE
CRITICAL FIRE WEATHER CONDITIONS FOR THE WA690 ZONE. FARTHER
SOUTH THE OR700 ZONE WILL NOT BE AS WINDY, HOWEVER CRITICAL
THRESHOLDS FOR RH ARE BEING MET MUCH LOWER AND 15% OR LESS.
VERY LOW CHANCES FOR ISOLATED (LESS THAN 10%) LIGHTNING / DRY
THUNDERSTORMS OVER THE OR700, MOUNTAINS OF CENTRAL OREGON AND
THE OCHOCO-JOHN DAY HIGHLANDS ZONES FRIDAY AFTERNOON AND
EVENING.
PRELIMINARY POINT TEMPS/POPS
PDT 50 86 54 92 / 0 0 0 0
ALW 55 87 60 93 / 0 0 0 0
PSC 54 90 58 96 / 0 0 0 0
YKM 53 89 60 96 / 0 0 0 0
HRI 53 89 57 95 / 0 0 0 0
ELN 50 86 57 91 / 0 0 0 0
RDM 45 87 50 91 / 0 0 0 0
LGD 47 86 52 92 / 0 0 0 0
GCD 46 89 50 94 / 0 0 0 10
DLS 56 90 63 94 / 0 0 0 0
PDT WATCHES/WARNINGS/ADVISORIES
WA...RED FLAG WARNING UNTIL 9 PM PDT THIS EVENING FOR WAZ690.
OR...RED FLAG WARNING UNTIL 9 PM PDT THIS EVENING FOR ORZ700.
DISCUSSION...71
AVIATION...86
FIRE WEATHER...71
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