652
FXUS66 KPQR 161735
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
1035 AM PDT FRI OCT 16 2026
UPDATED AVIATION DISCUSSION.
SYNOPSIS
CONDITIONS REMAIN DRY WITH WELL ABOVE AVERAGE
TEMPERATURES. EASTERLY WINDS WILL GRADUALLY WEAKEN AS A TROUGH
APPROACHES. A WEAK COLD FRONT WILL BRING CHANCES FOR LIGHT RAIN
LATE TONIGHT INTO SATURDAY MORNING, BEFORE HIGH PRESSURE RETURNS
DRY WEATHER SATURDAY NIGHT INTO SUNDAY. THE NEXT CHANCES FOR
RAIN ARE MONDAY INTO EARLY TUESDAY WITH AN APPROACHING LOW
PRESSURE SYSTEM, ALTHOUGH GUIDANCE CONTINUES TO TREND DRIER.
SHORT TERM...NOW THROUGH SATURDAY NIGHT
UPPER LEVEL RIDGING
WILL CONTINUE SHIFTING EAST AS TROUGHING OVER THE NORTHEAST
PACIFIC AND ALASKA PROGRESSES EASTWARD. CONDITIONS REMAIN DRY
ACROSS THE REGION WITH ANOTHER DAY OF ABOVE NORMAL TEMPERATURES.
HIGHS IN THE MID TO UPPER 70S ACROSS THE INTERIOR LOWLANDS,
10-15 DEGREES ABOVE THE NORMAL LOW TO MID 60S. HIGHS ALONG THE
COAST WILL BE MUCH CLOSER TO NORMAL AS THE OFFSHORE PRESSURE
GRADIENT CONTINUES TO WEAKEN, ALLOWING WESTERLY ONSHORE FLOW TO
RETURN AND MARINE STRATUS TO PUSH INTO THE COAST. HIGHS EXPECTED
TO TOP OUT IN THE LOW TO MID 60S. HIGH LEVEL CLOUDS WILL ALSO
INCREASE THROUGH THE DAY AS THE UPPER LEVEL TROUGH PROGRESSES.
THE OFFSHORE PRESSURE GRADIENT BETWEEN TROUTDALE AND THE DALLES
WILL CONTINUE TO WEAKEN THROUGH THE DAY WHICH WILL GRADUALLY
DECREASE EASTERLY WINDS TO LESS THAN 10 MPH BY THE AFTERNOON.
AN EMBEDDED SHORTWAVE TROUGH PASSING TO THE NORTH WILL GLANCE
THE REGION, SENDING A COLD FRONT THROUGH THE AREA TONIGHT AND
INTO SATURDAY MORNING. THIS WILL BRING MODERATE TO LOW CHANCES
OF LIGHT RAIN TO NORTHERN PORTIONS OF THE FORECAST AREA FOR
SATURDAY MORNING. MEAN QPF VALUES RANGE FROM A TRACE TO 0.10
INCH, GENERALLY NORTH OF LINCOLN CITY AT THE COAST AND FROM THE
PORTLAND METRO AREA NORTHWARD, WITH HIGHEST CHANCES FOR RAIN IN
THE SOUTHWEST WA CASCADES. CONDITIONS EXPECTED TO DRY OUT BY THE
AFTERNOON WITH NORTHERLY WINDS BEHIND THE FRONT. HIGHS WILL BE
CLOSER TO NORMAL, TOPPING OUT IN THE MID TO UPPER 60S ACROSS THE
INTERIOR VALLEYS. WILL NEED TO KEEP AN EYE ON SATURDAY NIGHT AS
CLOUDS CLEAR AND TEMPERATURES DROP INTO THE 30S. OUTSIDE OF THE
CASCADES, THE COOLEST TEMPERATURES ARE EXPECTED IN THE UPPER
HOOD RIVER VALLEY. -19/DH
LONG TERM...SUNDAY THROUGH THURSDAY
DRY WEATHER EXPECTED ON
SUNDAY AS FLOW ALOFT BECOMES MORE ZONAL WITH THE PASSAGE OF THE
SHORTWAVE TROUGH. HIGHS VERY SIMILAR TO SATURDAY PEAKING IN THE
MID 60S FOR MOST INTERIOR LOWLANDS AND MID 50S TO LOW 60S ALONG
THE COAST. SUNDAY NIGHT INTO MONDAY MORNING WILL BRING ANOTHER
CHANCE FOR FROST IN THE UPPER HOOD RIVER VALLEY AND THE SOUTHERN
WILLAMETTE VALLEY AS LOWS COULD DROP INTO THE MID TO UPPER 30S.
CLUSTER ANALYSIS CONTINUES TO DEPICT A TROUGH IMPACTING THE
REGION MONDAY AND TUESDAY BUT TRENDS HAVE THE TROUGH TAKING A
MORE SOUTHEAST TRAJECTORY AND JUST GLANCING NW OR AND SW WA.
APPROXIMATELY 40% OF ENSEMBLE MEMBERS HAVE LIGHT QPF FOR THE
PORTLAND AREA WHILE 60% OF MEMBERS HAVE LIGHT QPF AROUND
NEWPORT. MODELS CONTINUE TO TRACK THIS TROUGH MORE TOWARDS
NORTHERN CALIFORNIA, LIMITING ANY DECENT RAINFALL ACROSS THE
FORECAST AREA. CHANCES FOR 24-HOUR RAINFALL TOTALS EXCEEDING
0.25 INCHES BETWEEN 5 AM MONDAY TO 5 AM TUESDAY HAVE DROPPED TO
10-15% ALONG THE COAST AND COAST RANGE, SOUTHERN WILLAMETTE
VALLEY, AND THE OR CASCADE FOOTHILLS.
BY WEDNESDAY, ENSEMBLES SHOW THE UPPER TROUGH SWINGING INTO
CENTRAL CALIFORNIA, WHILE WEAK HIGH PRESSURE SHIFTS OVER THE
PACIFIC NORTHWEST, FAVORING PREDOMINATELY DRY CONDITIONS. AT THE
SAME TIME, IT DOES APPEAR THAT ANOTHER UPPER-LEVEL TROUGH WILL
BEGIN TO APPROACH BRITISH COLUMBIA AND POTENTIALLY MAKE ITS WAY
DOWN INTO THE PACIFIC NORTHWEST LATE NEXT WEEK, RETURNING
CHANCES FOR PRECIPITATION. -19/DH
AVIATION...THROUGH 18Z SATURDAY
LARGELY VFR CONDITIONS
EXPECTED THROUGH 00Z SAT ALONG THE COAST AND THROUGH 12Z SAT
INLAND. HIGH CLOUD COVERAGE WILL TEND TO INCREASE AHEAD OF AN
APPROACHING FRONT. MARINE STRATUS WILL SEE 70-90% CHANCES FOR
IFR CIGS AT COASTAL TERMINALS AFTER 00-03Z SAT, BEFORE CHANCES
FOR RAIN INCREASE AFTER 06-09Z SAT. HIGHEST CONFIDENCE IN RAIN
IS ALONG THE NORTH OR/SOUTH WA COAST (KAST, KTMK). INLAND,
CHANCES FOR MVFR CIGS REACH 60-70% AFTER 12Z SAT WHILE THE
CHANCES FOR RAIN PEAK AT 30-60% FROM 12-15Z SAT.
GUSTY EAST WINDS CONTINUE THROUGH THE WESTERN COLUMBIA GORGE,
SUPPORTING CONTINUED GUSTS TO 20-30 KT AT KTTD INTO THIS
AFTERNOON BEFORE THE OFFSHORE PRESSURE GRADIENT EASES AS THE
FRONTAL BOUNDARY APPROACHES. ELSEWHERE, LIGHT WINDS INLAND AND
WEST TO NORTHWEST WINDS ALONG THE COAST WILL TURN OUT OF THE
SOUTH TO SOUTHWEST AT AROUND 5 KT AHEAD OF THE FRONTAL PASSAGE.
KPDX AND APPROACHES...VFR CONDITIONS WITH INCREASING HIGH CLOUD
COVER THROUGH THIS EVENING AND INTO TONIGHT. A PASSING FRONT
WILL BRING CHANCES FOR MVFR CIGS AND LIGHT RAIN FROM 12-15Z SAT.
LIGHT EAST WINDS MAY REACH THE TERMINAL THIS AFTERNOON BEFORE
TURNING SOUTHERLY AHEAD OF THE FRONTAL PASSAGE TONIGHT. -36
MARINE
BENIGN MARINE CONDITIONS CONTINUE. NORTHWEST WINDS
TURN SOUTHERLY THIS AFTERNOON INTO THE EVENING AS A WEAK FRONT
PASSES THROUGH. WINDS TURN BACK TO THE NORTHWEST ON SATURDAY
BEHIND THE FRONT. SEAS REMAIN AROUND 4-7 FT AT 10-12 SECONDS
THROUGH EARLY SATURDAY MORNING.
A STEEPER NORTHWESTERLY SWELL ARRIVES THIS WEEKEND, BUILDING
SEAS TO 7-9 FT BY SATURDAY EVENING AND 10-13 FT EARLY NEXT
WEEK. UNCERTAINTY REMAINS ON HOW HIGH SEAS WILL RISE EARLY NEXT
WEEK DUE TO UNCERTAINTY ON THE TRACK OF THE LOW PRESSURE SYSTEM
ASSOCIATED WITH THE SWELL. THERE IS A 15-30% CHANCE FOR SEAS
EXCEEDING 15 FT ON MONDAY, WITH THE HIGHEST CHANCES BEYOND 30-40
NM. WILL ALSO NOTE THAT THE LONG PERIODS FROM THE SWELLS WILL
RESULT IN A MODERATE SNEAKER WAVE THREAT FRIDAY INTO EARLY NEXT
WEEK. CAUTION SHOULD BE USED WHEN IN OR NEAR THE WATER. -19/03
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...NONE.
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