777
FXUS66 KPQR 270530
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
1030 PM PDT WED AUG 26 2026
UPDATED AVIATION DISCUSSION.
SYNOPSIS
A COOL AND INCREASINGLY UNSETTLED PATTERN WILL
CONTINUE THROUGH THE END OF THE WEEK AS UPPER-LEVEL TROUGHING
SETTLES OVER THE PACIFIC NORTHWEST. PERIODIC MARINE PUSHES AND
WEAK FRONTAL PASSAGES WILL BRING INCREASING CLOUD COVER AND LOW
CHANCES FOR PRECIPITATION, WITH THE BEST OPPORTUNITIES ALONG THE
COAST AND HIGHER TERRAIN. TEMPERATURES MAY BRIEFLY REBOUND
SUNDAY, ALTHOUGH UNCERTAINTY INCREASES INTO EARLY NEXT WEEK.
DISCUSSION...NOW THROUGH TUESDAY
UPPER-LEVEL TROUGHING OVER THE
NORTHEAST PACIFIC CONTINUES TO SHIFT NORTHEASTWARD TOWARDS
BRITISH COLUMBIA, WITH COOLER AIR GRADUALLY SPREADING INTO THE
PACIFIC NORTHWEST. THIS ONSHORE WIND PATTERN RESULTED IN MARINE
STRATUS FUNNELING INTO THE INTERIOR LOWLANDS EARLY THIS MORNING,
BUT HAS ALREADY BURNED OFF INLAND AS OF NOON, LEAVING JUST
BROKEN STRATUS ALONG THE COAST. TEMPERATURES WILL REMAIN NEAR
SEASONAL NORMS TODAY, WITH HIGHS IN THE LOW 80S INLAND AND 60S
ALONG THE COAST.
ANOTHER SURGE OF MARINE STRATUS IS EXPECTED TONIGHT INTO
THURSDAY MORNING AS ONSHORE FLOW STRENGTHENS. A SHORTWAVE
EMBEDDED WITHIN THE BROADER TROUGH WILL MOVE ACROSS THE REGION
THURSDAY MORNING, ACCOMPANIED BY A WEAK FRONTAL BOUNDARY.
PRECIPITATION CHANCES REMAIN HIGHEST ALONG THE COAST AND COAST
RANGE, GENERALLY 10 TO 30 PERCENT, WITH LOCALLY HIGHER CHANCES
OF 30 TO 40 PERCENT ACROSS PACIFIC COUNTY. ELSEWHERE, MEASURABLE
PRECIPITATION CHANCES REMAIN 5 PERCENT OR LESS. COOLER AIR
ACCOMPANYING THE DISTURBANCE WILL LOWER INTERIOR HIGHS INTO THE
MID TO UPPER 70S THURSDAY, WHILE COASTAL LOCATIONS REMAIN IN THE
60S. LITTLE CHANGE IS EXPECTED FRIDAY AS THE UPPER TROUGH
REMAINS IN PLACE. CONTINUED ONSHORE FLOW WILL FAVOR ANOTHER
ROUND OF MORNING MARINE STRATUS, WITH AFTERNOON TEMPERATURES
REMAINING IN THE MID TO UPPER 70S ACROSS THE INTERIOR.
A REINFORCING DISTURBANCE MAY BRING A BETTER OPPORTUNITY FOR
PRECIPITATION SATURDAY, PARTICULARLY ACROSS AREAS NORTH OF
SALEM. CURRENT ENSEMBLE PROBABILITIES FOR MEASURABLE RAINFALL
ARE AROUND 15 TO 30 PERCENT, ALTHOUGH CONSIDERABLE UNCERTAINTY
REMAINS REGARDING THE STRENGTH AND TRACK OF THIS FEATURE.
TEMPERATURES SHOULD REMAIN ON THE COOL SIDE, WITH HIGHS
GENERALLY IN THE MID 70S.
THE UPPER-LEVEL PATTERN BEGINS TO FLATTEN DURING SUNDAY, WHICH
SHOULD ALLOW TEMPERATURES TO GRADUALLY RECOVER TOWARD THE UPPER
70S TO MAYBE 80. HOWEVER, ENSEMBLE GUIDANCE CONTINUES TO SHOW
CONSIDERABLE SPREAD HEADING INTO EARLY NEXT WEEK, WITH SOME
SOLUTIONS FAVORING RENEWED TROUGHING AND PRECIPITATION WHILE
OTHERS MAINTAIN A MORE PROGRESSIVE AND DRIER PATTERN. CONFIDENCE
THEREFORE REMAINS RELATIVELY LOW BEYOND THE WEEKEND, WHERE HIGH
TEMPERATURES COULD REACH ANYWHERE BETWEEN 70 AND 80 DEGREES. ~12
AVIATION...THROUGH 06Z FRIDAY
AN UPPER-LEVEL LOW OFFSHORE
WILL CONTINUE TO BRING ONSHORE FLOW AND SUPPORT THE INLAND
PENETRATION OF LOW MARINE CLOUDS THROUGH TONIGHT. AT THE COAST,
MVFR/IFR CIGS ARE FAVORED THROUGH THE MORNING, ALTHOUGH THERE IS
ONLY MODERATE CONFIDENCE, 40-70%, IN IFR OCCURRENCE, HIGHEST
ALONG THE CENTRAL OREGON COAST AND DECREASING TO THE NORTH. AT
INLAND TERMINALS, THE HIGHEST CHANCES FOR MVFR CIGS ARE ALONG
THE LOWER COLUMBIA, IN THE PORTLAND AREA, AND IN THE SOUTHERN
WILLAMETTE VALLEY. MVFR CHANCES REACH 50-70% IN THE HOURS AROUND
SUNRISE, FROM 12-17Z THU. WIDELY SCATTERED RAIN SHOWERS ARE
POSSIBLE NEAR THE UPPER LOW, WITH 30% CHANCES FOR RESTRICTED VIS
WITHIN LIGHT RAIN AT KAST FROM 16-22Z THU. OTHERWISE,
CONDITIONS SHOULD TEND TO IMPROVE THROUGH THE DAY THURSDAY TO
VFR INLAND AND MVFR AT COASTAL TERMINALS. SOUTH TO SOUTHWESTERLY
WINDS AROUND 5 KT OVERNIGHT WILL BUILD TO 5-10 KT BY MIDDAY
THURSDAY, ALTHOUGH GUSTS TO 20 KT ARE EXPECTED CLOSER TO THE LOW
AT KAST. WINDS THEN VEER THROUGH WESTERLY TO NORTHWESTERLY BY
THURSDAY EVENING.
KPDX AND APPROACHES...VFR CONDITIONS LIKELY TO PREVAIL INTO
TONIGHT, WITH INCREASING CHANCES FOR MVFR CIGS AFTER 12Z THU,
REACHING 50-70% FROM 14-17Z THU BEFORE LOW CLOUDS BEGIN TO MIX
OUT. SOUTHERLY WINDS AROUND 3-5 KT THROUGH TONIGHT STEADILY VEER
TO SOUTHWESTERLY THROUGH THURSDAY MORNING TO NORTHWESTERLY BY
THURSDAY EVENING. -36
MARINE
LOW PRESSURE CENTERED 300 MILES WEST OF THE
WASHINGTON COAST WILL CONTINUE TO TRACK TOWARD VANCOUVER ISLAND
THROUGH THURSDAY. SOUTHERLY WINDS WILL CONTINUE ACROSS THE
COASTAL WATERS, GENERALLY AROUND 10-15 KT. A WEAK FRONT WILL
MOVE ACROSS THE WATERS THURSDAY MORNING BRIEFLY INCREASING
SOUTHERLIES UP TO 20 KT. COULD SEE A BRIEF PERIOD OF ISOLATED
GUSTS UP TO 25 KT ACROSS THE INNER WATERS NORTH OF CAPE FALCON
AND AROUND THE COLUMBIA RIVER BAR BETWEEN 8 AM AND 2 PM.
HIGH PRESSURE BEGINS TO REBUILD OVER THE WATERS LATER THURSDAY
INTO FRIDAY RETURNING NORTH TO NORTHWEST WINDS ACROSS THE COASTAL
WATERS INTO THE WEEKEND. PREDOMINATELY WIND DRIVEN SEAS ARE
EXPECTED TO REMAIN AROUND 3 TO 6 FT THROUGH THE WEEKEND. SOMEWHAT
MORE ACTIVE PATTERN MAY RETURN EARLY NEXT WEEK. /DH
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...NONE.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
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