138
FXUS66 KPQR 271747 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATE
NATIONAL WEATHER SERVICE PORTLAND OR
1047 AM PDT THU AUG 27 2026
UPDATED AVIATION DISCUSSION
SYNOPSIS
A COOL AND INCREASINGLY UNSETTLED PATTERN WILL
CONTINUE THROUGH THE WEEKEND 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 WEDNESDAY
CONDITIONS CONTINUE TO BE
DOMINATED BY UPPER LEVEL TROUGHING OVER THE NORTHEAST PACIFIC.
MARINE STRATUS ALONG THE COAST IS AGAIN EXPECTED TO PUSH INTO
THE INTERIOR AS ONSHORE FLOW CONTINUES. A SHORTWAVE EMBEDDED
WITHIN THE LARGER UPPER LEVEL TROUGH WILL PASS OVERHEAD THIS
MORNING, SENDING A WEAK COLD FRONT THROUGH THE AREA. CHANCES
FOR MEASURABLE PRECIPITATION CONTINUE TO VARY ACROSS THE AREA
WITH THE BEST CHANCES OVER THE COAST, COAST RANGE, AND CASCADE
FOOTHILLS. CHANCES OVER THESE AREA ARE 10-30% WITH LOCALLY
HIGHER CHANCES OVER PACIFIC AND WAHKIAKUM COUNTIES IN WA AT
40-60%. ELSEWHERE, CHANCES ARE 5% OR LESS. THE DOWNWARD TREND IN
HIGHS CONTINUES WITH TEMPERATURES LIKELY TOPPING OUT IN THE
UPPER 70S ACROSS THE INTERIOR LOWLANDS WHILE THE COAST REMAINS
IN THE 60S.
THE PATTERN REMAINS VERY SIMILAR HEADING INTO FRIDAY. UPPER LEVEL
TROUGHING PERSISTS WITH NORTHERLY ONSHORE AT THE SURFACE SUPPORTING
MARINE STRATUS DURING THE MORNING AND AFTERNOON HIGH TEMPERATURES IN
THE UPPER 70S. HEADING INTO SATURDAY, TROUGHING PERSISTS BUT A
REINFORCING DISTURBANCE COULD BRING A BETTER CHANCE FOR
PRECIPITATION. PROBABILITIES FOR MEASURABLE RAINFALL (0.01
INCHES) ARE 10-30% FOR AREAS NORTH SALEM.
THE PATTERN BEGINS TO FLATTEN OUT DURING THE SECOND HALF OF THE
WEEKEND WHICH WOULD ALLOW TEMPERATURES TO REBOUND TOWARD THE UPPER
70S. ENSEMBLE CLUSTERS FAVOR A COOLER, POSSIBLY WET PATTERN HEADING
INTO EARLY TO MIDDLE OF NEXT WEEK. AN INCREASING NUMBER OF ENSEMBLE
MEMBERS DO SHOW MEASURABLE PRECIPITATION ACROSS MUCH OF THE
AREA BUT DO STILL SHOW CONSIDERABLE DIFFERENCES IN TIMING AND
STRENGTH OF UPPER LEVEL TROUGHING THAT DEVELOPS. -19
AVIATION...THROUGH 18Z FRIDAY
SOUTHWEST FLOW ALOFT CONTINUES AS
AN UPPER LEVEL TROUGH PERSISTS OVER THE REGION. LIGHT RAIN SHOWERS
CONTINUE NEAR KAST AS A WEAK FRONT PUSHES ONSHORE TODAY. THIS IS
PRODUCING PREDOMINATELY MVFR CONDITIONS AT THE COAST, WITH
PERIODS OF REDUCED VIS. A FEW LOW CLOUDS ARE ALSO EXPECTED TO PUSH
INLAND, GENERALLY REMAINING VFR, BUT BRIEF MVFR CIGS WILL BE
POSSIBLE INTO EARLY THIS AFTERNOON. GUIDANCE SUGGESTS INCREASING
CHANCES (AROUND 50% NEAR KONP) FOR LIFR CONDITIONS DEVELOPING
ALONG THE CENTRAL OREGON COAST AFTER 02Z FRIDAY. THE BEST CHANCES
FOR MVFR STRATUS DEVELOPING INLAND FRIDAY MORNING (12-14Z) WILL BE
ALONG THE COLUMBIA RIVER (INCLUDING KTTD AND KPDX) AS WELL AS IN
THE SOUTHERN WILLAMETTE VALLEY (KEUG). SOUTH TO SOUTHWEST WINDS
TODAY ARE EXPECTED TO BECOME MORE WESTERLY LATER THIS AFTERNOON.
KPDX AND APPROACHES...PREDOMINATELY VFR CONDITIONS EXPECTED
THROUGH THE PERIOD. A WEAK FRONT PUSHING INLAND BRINGS LOW CHANCES
FOR BROKEN MVFR CIGS INTO EARLY AFTERNOON. THERE IS ALSO A 20-30%
CHANCE FOR MVFR STRATUS DEVELOPING NEAR THE TERMINALS AFTER 12Z
FRIDAY. RELATIVELY LIGHT SSW WINDS ARE EXPECTED TO VEER WESTERLY
THIS AFTERNOON, BECOMING NORTHWEST 6-8 KT BY 00Z FRIDAY. /DH
MARINE
LOW PRESSURE CONTINUES TO TRACK TOWARD VANCOUVER
ISLAND TODAY, SUPPORTING SOUTHERLY WINDS 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 THROUGH EARLY THIS AFTERNOON.
HIGH PRESSURE BEGINS TO REBUILD OVER THE WATERS LATER TODAY
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. -19/DH
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...NONE.
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