765
FXUS66 KPQR 162320
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
420 PM PDT SUN AUG 16 2026
UPDATED AVIATION DISCUSSION.
SYNOPSIS
SEASONABLY WARM AND DRY CONDITIONS EXPECTED THROUGH
MUCH OF THE WEEK WITH MORNING CLOUDS AND AFTERNOON CLEARING.
WINDS GENERALLY OUT OF THE WEST TO NORTHWEST, STRONGEST IN THE
AFTERNOON AND ALONG THE CENTRAL COLUMBIA RIVER GORGE AND UPPER
HOOD RIVER VALLEY. NEXT BEST CHANCES FOR LIGHT RAINFALL ARRIVE
FRIDAY INTO NEXT WEEKEND.
DISCUSSION...NOW THROUGH SATURDAY
SEASONABLY DRY AND WARM
CONDITIONS CONTINUE THROUGH THE WEEK WITH MINIMAL WEATHER
IMPACTS. THE LARGE-SCALE PATTERN REMAINS FAIRLY STAGNANT THROUGH
THE PERIOD, WITH BROAD AND RELATIVELY FLAT UPPER-LEVEL RIDGING
OVER THE MAJORITY OF CONUS AND A WEAK, POSITIVELY-TILTED UPPER-
LEVEL TROUGHING OVER THE NORTHEAST PACIFIC. THIS PATTERN WILL
SUPPORT CONTINUED ONSHORE FLOW, MAINTAINING NEAR-NORMAL DAILY
HIGH TEMPERATURES IN THE 80S WITHIN INLAND VALLEYS AND 60S ALONG
THE COAST, AND OVERNIGHT LOWS IN THE 50S ACROSS THE REGION.
MORNINGS WILL BE CHARACTERIZED BY CLOUDS, ESPECIALLY ALONG THE
COAST, WHICH WILL TEND TO CLEAR BY THE AFTERNOON. LIGHT WEST TO
NORTHWEST WINDS WILL, PEAKING EACH AFTERNOON. THE STRONGEST
WINDS ARE LIKELY TO BE ALONG THE CENTRAL COLUMBIA RIVER GORGE
AND HOOD RIVER VALLEY, BUT IMPACTS ARE NOT ANTICIPATED.
THE MAJORITY OF ENSEMBLE MEMBERS ARE IN AGREEMENT THAT UPPER-
LEVEL RIDGING OVER THE ROCKIES AND GREAT BASIN WILL BUILD LATE
IN THE WORKWEEK, WHICH WOULD FAVOR A BRIEF WARM-UP ON THURSDAY.
HOWEVER, ENSEMBLE GUIDANCE SHOWS THE UPPER-LEVEL TROUGH OVER
THE NORTHEAST PACIFIC SHIFTING ONSHORE FRIDAY INTO THE WEEKEND,
RESULTING IN SLIGHTLY COOLER TEMPERATURES AND WINDS COMING FROM
THE WEST TO SOUTHWEST. CHANCES FOR PRECIPITATION ALSO INCREASE
TO 10-30% ACROSS THE REGION DURING THIS TIME, HOWEVER, THERE IS
STILL HIGH UNCERTAINTY IN THE TIMING AND POTENTIAL RAIN AMOUNTS.
A WEAKER FRONT AT THE END OF THE WEEK WOULD HAVE A HARD TIME
COUNTERACTING THE DRY AIRMASS IN PLACE AND MAKE ACCUMULATING
RAINFALL UNLIKELY. -10/36
AVIATION...THROUGH 00Z TUESDAY
EARLIER MARINE STRATUS HAS
LARGELY CLEARED THIS AFTERNOON, ASIDE FROM THE AREAS AROUND
GRAYS HARBOR AND THE MOUTH OF THE COLUMBIA RIVER INCLUDING
KAST, BUT FURTHER CLEARING SHOULD FAVOR VFR FLYING CONDITIONS
WITH SCT LOW CLOUDS INTO THIS EVENING. ELSEWHERE, LARGELY CLEAR
SKIES BENEATH SCT HIGH CIRRUS COVERAGE WILL ALSO CONTINUE TO
SUPPORT VFR CONDITIONS. NORTH TO NORTHWEST WINDS OF 5-10 KT AT
INLAND TERMINALS AND 10-15 KT WITH GUSTS UP TO 20 KT ALONG THE
COAST WILL EASE BELOW 5 KT BY 06-09Z MON.
ADDITIONAL LOW STRATUS IS EXPECTED TO DEVELOP ALONG THE COAST
AND PUSH INLAND TONIGHT, WITH SOME UNCERTAINTY IN CLOUD
COVERAGE WITHIN INTERIOR VALLEYS. THERE IS HIGH CONFIDENCE IN
MVFR/IFR CONDITIONS (70-90% CHANCE) AT COASTAL TERMINALS BY
09-12Z MON, BUT ONLY 50-60% CHANCES AFTER 12Z MON INLAND. ANY
LOW CLOUDS WILL BEGIN TO MIX OUT BY 17-18Z MON INLAND, WHILE
PERSISTENT MVFR CIGS ARE MORE LIKELY ALONG THE COAST. NORTH TO
NORTHWEST WINDS WILL AGAIN BUILD TO 5-10 KT INLAND AND 10-15 KT
GUSTING 20-25 KT AT COASTAL TERMINALS BY 18Z MON.
KPDX AND APPROACHES...HIGH CONFIDENCE IN CONTINUED VFR
CONDITIONS BENEATH SCT HIGH CLOUDS THROUGH 06-09Z MON. CHANCES
FOR MVFR CIGS THEN INCREASE AS LOW STRATUS PUSHES INLAND,
REACHING 50-60% FROM 12-17Z MON BEFORE LOW CLOUD MIX OUT BY THE
LATE MORNING. DIURNAL NORTHWEST WINDS EASE BELOW 5 KT BY 06-09Z
MON, THEN BUILD AGAIN TO 5-10 KT BY 18Z MON. -36
MARINE
A LARGELY STAGNANT PATTERN CONTINUES THROUGH MUCH OF
THE WEEK WITH HIGH PRESSURE OFFSHORE SUPPORTING NORTHERLY TO
NORTHWESTERLY WINDS OF 8-15 KT AND AFTERNOON GUSTS UP TO 20 KT.
WEAK LOW PRESSURE MOVING OVER THE NORTHEAST PACIFIC FRIDAY INTO
NEXT WEEKEND WILL SHIFT WINDS OUT OF THE WEST TO SOUTHWEST
ACROSS THE WATERS, BUT CHANCES FOR GUSTS EXCEEDING 21 KT REMAIN
LOW, ONLY 5-10%. BENIGN SEAS OF 3-6 FT PERSIST THROUGH THE
PERIOD. -10/36
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...NONE.
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