188
FXUS66 KPQR 241130
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
430 AM PDT FRI JUL 24 2026
UPDATED AVIATION DISCUSSION.
SYNOPSIS
A FINAL WARM DAY IS EXPECTED ON FRIDAY BEFORE A
RETURN TO MORE SEASONABLE TEMPERATURES ACROSS THE REGION
BEGINNING THIS WEEKEND, WHEN A PASSING FRONT WILL BEING CHANCES
FOR LIGHT SHOWERS TO THE COAST AND COAST RANGE. SIMILAR
CONDITIONS PERSIST INTO NEXT WEEK.
DISCUSSION...NOW THROUGH THURSDAY
A PATTERN TRANSITION
CONTINUES TODAY AS UPPER-LEVEL TROUGHING DEVELOPS OVER THE GULF
OF ALASKA WHILE THE UPPER RIDGE AXIS OVER THE GREAT BASIN SHIFTS
EASTWARD OVER THE ROCKIES. FOR TODAY, HEIGHTS ALOFT REMAIN HIGH
LEADING TO ONE FINAL DAY OF HEAT AS INLAND VALLEY TEMPERATURES
RISE TO AFTERNOON HIGHS IN THE MID TO UPPER 80S, SUPPORTING
WIDESPREAD MINOR HEATRISK. CONTINUED ONSHORE FLOW WILL SEE
MARINE STRATUS PENETRATE INLAND, ALTHOUGH THE MAJORITY OF LOW
CLOUDS WILL BURN OFF BY THIS AFTERNOON EXCEPT ALONG THE COAST.
THIS WEEKEND, A CLOSED LOW OVER THE NORTHEAST PACIFIC WILL OPEN
INTO THE DEVELOPING UPPER-LEVEL TROUGH BEFORE PASSING OVERHEAD
AS AN UPPER SHORTWAVE. THIS WILL RESULT IN COOLER TEMPERATURES
ALOFT, REFLECTED AT THE SURFACE AS SLIGHTLY BELOW-NORMAL HIGHS
ON SATURDAY, AND NEAR-NORMAL ON SUNDAY. INCREASED ONSHORE FLOW
AND SYNOPTIC ASCENT MAXIMIZED AS THE SHORTWAVE AND ASSOCIATED
WEAK SURFACE FRONT NEAR THE COAST WILL RESULT IN MODEST CHANCES,
GENERALLY 15-25% FROM FLORENCE TO TILLAMOOK AND 25-45% FROM
TILLAMOOK NORTH INTO SOUTHWEST WASHINGTON, FOR LIGHT RAIN
SHOWERS OR DRIZZLE SATURDAY INTO SUNDAY, MOST LIKELY LATE
SATURDAY NIGHT AND EARLY SUNDAY MORNING. ANY RAIN ACCUMULATION
WILL MOST LIKELY BE VERY LIGHT, 0.05 INCHES OR LESS. SOUTHERLY
TO SOUTHWESTERLY WINDS WILL INCREASE AHEAD OF THE FRONTAL
BOUNDARY SATURDAY AFTERNOON, WITH PEAK GUSTS OF 30-35 MPH ON THE
COAST AND 20-25 MPH INLAND. STRONGER WEST WINDS THROUGH THE
COLUMBIA GORGE MAY ALSO REACH 30-35 MPH.
BY NEXT WEEK, THE LARGE-SCALE PATTERN OF UPPER TROUGHING OVER
THE GULF OF ALASKA AND RIDGING OVER THE ROCKIES AND CENTRAL
PLAINS LOOKS TO REMAIN FAIRLY PERSISTENT. THIS PATTERN WILL
FAVOR CONTINUED ONSHORE FLOW SUPPORTING SEASONABLE TEMPERATURES
WITH A FAIRLY NARROW DISTRIBUTION OF ENSEMBLE SOLUTIONS THROUGH
MUCH OF THE WEEK GIVEN THE LEAD TIME. SHORTWAVES TRANSITING THE
REGION WITHIN THE SOUTHWESTERLY FLOW ALOFT MAY BRING FURTHER
CHANCES FOR LIGHT PRECIPITATION, PARTICULARLY ALONG THE COAST,
BUT THE UNCERTAINTY IN THE POSITION AND TIMING OF THESE FEATURES
IS LOW AT THIS TIME. -36
AVIATION...THROUGH 12Z SATURDAY
VFR CONDITIONS INLAND
EXPECTED TO PREVAIL THROUGHOUT THE PERIOD, WHILE LATEST
SATELLITE IMAGERY DEPICTS SOME LOW CLOUDS REACHING INLAND
THROUGH GAPS IN COASTAL TERRAIN AS WELL AS BEGINNING TO BUILD
ALONG THE CASCADE FOOTHILLS EARLY THIS MORNING. CHANCES FOR MVFR
CIGS BENEATH LOW CLOUD COVER IS LOW (10-25%) AT TERMINALS ALONG
THE I-5 CORRIDOR, BUT AS HIGH AS 25-40% CLOSER TO THE CASCADES,
MOST NOTABLY AT KTTD. ANY LOW CLOUDS WILL MIX OUT BY MIDDAY
FRIDAY. SATELLITE IMAGERY ALSO SHOWS WIDESPREAD COVERAGE OF LOW
CLOUDS ALONG THE COAST, YIELDING IFR CONDITIONS AT COASTAL
TERMINALS ALONG THE CENTRAL/NORTHERN OR AND SOUTHERN WA COASTS.
THESE CONDITIONS ARE LIKELY TO PREVAIL THROUGH 17-19Z FRI, WHEN
CLOUD BASES LIFTING ABOVE 1-1.5 KFT AND CLEARING SOMEWHAT WILL
INSTEAD FAVOR VFR/MVFR CONDITIONS. LIGHT AND VARIABLE WINDS
ACROSS THE REGION EARLY THIS MORNING WILL BUILD OUT OF THE WEST
TO NORTHWEST TO 6-12 KT BY 18-21Z FRI, THEN EASE AND TURN OUT OF
THE SOUTH TO SOUTHWEST LATE IN THE PERIOD.
KPDX AND APPROACHES...VFR CONDITIONS FAVORED THROUGH THE PERIOD
WITH A 25% CHANCE FOR MVFR CIGS THROUGH 16-18Z AS LOW STRATUS
DEVELOPS AND BUILDS WESTWARD FROM THE CASCADE FOOTHILLS THROUGH
THE REMAINDER OF THE OVERNIGHT PERIOD. ANY LOW CLOUDS ARE
EXPECTED TO ERODE BY MIDDAY. NORTHWEST WINDS AT LESS THAN 5 KT
EARLY THIS MORNING WILL BUILD TO 5-10 KT THIS AFTERNOON, BEFORE
TURNING OUT OF THE SOUTH-SOUTHEAST LATE IN THE PERIOD. -36
MARINE
WEAK LOW PRESSURE OFFSHORE CONTINUES TO SUPPORT LIGHT
WINDS OF 5-10 KT OR LESS AND SEAS OF 4-6 FT EARLY THIS MORNING.
AS A FRONT APPROACHES THE WATERS ON SATURDAY, SOUTHERLY WINDS
WILL INCREASE TO 15-25 KT WITH GUSTS UP TO 30 KT SATURDAY
AFTERNOON. GIVEN HIGH CONFIDENCE (80-90%) IN GUSTS TO AT LEAST
25 KT ACROSS THE WATERS, A SMALL CRAFT ADVISORY HAS BEEN HOISTED
FROM 8 AM THROUGH 8 PM SATURDAY ACROSS THE WATERS, AND FROM 11
AM THROUGH 8 PM SATURDAY AT THE COLUMBIA RIVER BAR. SEAS DURING
THIS TIME WILL ALSO BUILD SLIGHTLY TO 5-8 FT WITH A DOMINANT
NORTHWEST SWELL AT 8-9 SECONDS. BEHIND THE FRONTAL BOUNDARY,
WINDS QUICKLY EASE DOWN TO AROUND 10 KT OUT OF THE SOUTH AND
SEAS TO 3-5 FT, PERSISTING THROUGH AT MIDWEEK. SEASONABLE
NORTHERLY FLOW RETURNS WEDNESDAY, CONTINUING THROUGH THE END OF
THE WEEK. -36
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 11 AM TO 8 PM PDT SATURDAY FOR
PZZ210.
SMALL CRAFT ADVISORY FROM 8 AM TO 8 PM PDT SATURDAY FOR
PZZ251>253-271>273.
WWW.WEATHER.GOV/PORTLAND
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