375
FXUS66 KPQR 071209
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
409 AM PST FRI NOV 7 2025
SYNOPSIS
LINGERING SHOWERS ACROSS THE AREA THROUGH FRIDAY
MORNING AS WEAKENING LOW PRESSURE MOVES FURTHER INLAND. DRY
WEATHER RETURNS THIS AFTERNOON AND PERSISTS THROUGH THE WEEKEND
AS HIGH PRESSURE BUILDS OVER THE PACIFIC NORTHWEST. EXPECT NEAR
TO SLIGHTLY ABOVE NORMAL TEMPERATURES AND INCREASED OFFSHORE
FLOW THIS WEEKEND. ANOTHER SHORTWAVE TROUGH RETURNS CHANCES FOR
SHOWERS ON MONDAY, WITH ANOTHER POTENTIAL SYSTEM MID-TO-LATE
NEXT WEEK.
DISCUSSION...NOW THROUGH THURSDAY NIGHT
RADAR IMAGERY AS OF
EARLY FRIDAY MORNING DEPICTS SCATTERED SHOWERS ACROSS NORTHWEST
OREGON AND SOUTHWEST WASHINGTON AS A WEAKENING LOW PRESSURE
SYSTEM PROGRESSES INLAND. TODAY (FRIDAY), AN UPPER LEVEL RIDGE
BUILDS OVER THE PACIFIC NORTHWEST, WHICH WILL DECREASE SHOWER
ACTIVITY THROUGHOUT THE DAY AND RETURN DRIER CONDITIONS. WE
SHOULD ALSO SEE SOME CLOUD BREAKS BY THIS AFTERNOON/EVENING.
THE RIDGE OF HIGH PRESSURE AMPLIFIES AND PERSISTS THROUGHOUT
THE WEEKEND, SO EXPECT DRY WEATHER AND NEAR-TO-SLIGHTLY ABOVE
NORMAL HIGH TEMPERATURES THROUGH SUNDAY (UPPER 50S TO LOW 60S).
ALSO WORTH MENTIONING IS THAT EASTERLY WINDS WILL INCREASE THIS
WEEKEND AS OFFSHORE PRESSURE GRADIENTS TIGHTEN. THE BREEZIEST
EASTERLY WINDS WILL BE THROUGH THE WESTERN COLUMBIA RIVER GORGE
AND PORTLAND/VANCOUVER METRO AREA, AND CASCADES. THE LATEST
MODEL GUIDANCE SUGGESTS THE SURFACE PRESSURE GRADIENT FROM
TROUTDALE (KTTD) TO THE DALLES (KDLS) WILL MOST LIKELY PEAK
AROUND -6 MB SATURDAY NIGHT BEFORE EASING TO AROUND -4 MB
SUNDAY AFTERNOON. THIS SUGGESTS PEAK WIND GUSTS UP TO 30-40 MPH
IN THE FAR EAST PORTLAND METRO AREA (TROUTDALE/CAMAS) AND UP TO
50 MPH FOR EXPOSED RIDGETOPS AND OUR TYPICALLY BREEZIEST SPOTS
LIKE CROWN POINT AND THREE CORNER ROCK.
SUNDAY NIGHT INTO MONDAY, THE UPPER RIDGE WILL BEGIN TO FLATTEN
AS A SHORTWAVE TROUGH DIPS SOUTH INTO SOUTHWEST BRITISH
COLUMBIA AND FAR NORTHWEST WASHINGTON. SINCE MOST ENSEMBLE
GUIDANCE SUGGEST THAT THIS SYSTEM WILL TRACK FURTHER NORTH OF
OUR AREA, PRECIPITATION AMOUNTS ARE NOT LOOKING SIGNIFICANT OR
IMPACTFUL. THE HIGHEST CHANCES FOR RAIN ARE ALONG THE COAST AND
SOUTHWEST WASHINGTON (50-70%), WHILE CHANCES FOR RAIN ARE LOWER
(20-40%) ACROSS INTERIOR NORTHWEST OREGON. CHANCES FOR 0.25" OF
RAIN OR MORE IN A 24 HR PERIOD FROM 4 AM MON - 4 AM TUE ARE ONLY
20-30% ALONG THE COAST AND 5-15% ACROSS THE WILLAMETTE VALLEY
AND SOUTHWEST WASHINGTON LOWLANDS.
ANOTHER UPPER LEVEL RIDGE BUILDS OVER THE PACIFIC NORTHWEST ON
TUESDAY, BRINGING A BRIEF RETURN OF DRY WEATHER. BY WEDNESDAY,
THIS RIDGE QUICKLY GETS PUSHED EASTWARD AS THE NEXT FRONTAL
SYSTEM APPROACHES. THE MAJORITY OF ENSEMBLE MEMBERS (70-80%) ARE
IN GENERAL AGREEMENT OF LIGHT RAIN RETURNING BY WEDNESDAY NIGHT
AND CONTINUING INTO THURSDAY. NOTE THAT THERE IS STILL SOME
UNCERTAINTY WITH EXACT PRECIPITATION AMOUNTS. -10
AVIATION
RADAR IMAGERY AND TERMINAL OBSERVATIONS AS OF EARLY
FRIDAY MORNING DEPICTS LINGERING SHOWERS AND MID-TO-HIGH LEVEL
CLOUD COVER ACROSS NORTHWEST OREGON AS A WEAKENING LOW PRESSURE
SYSTEM PROGRESSES INLAND. NOT EXPECTING FOG TONIGHT DUE TO CLOUD
COVER AND LACK OF CALM WINDS. HIGH PRESSURE BUILDING OVER THE
PACIFIC NORTHWEST ON FRIDAY WILL LEAD TO DECREASING SHOWERS AND
VFR CONDITIONS THROUGH THE MAJORITY OF THE TAF PERIOD. SOUTHERLY
TO SOUTHWESTERLY WINDS AROUND 5-8 KT THIS MORNING BECOME
VARIABLE UNDER 5 KT IN THE AFTERNOON AS PRESSURE GRADIENTS EASE.
AFTER 00Z SAT, GUIDANCE SUGGESTS INCREASING CLOUD BREAKS WHICH
PERSIST INTO LATE FRIDAY NIGHT. LATE IN THE TAF PERIOD (06-12Z
SAT), MOIST LOW LEVELS WILL SUPPORT A 20-30% CHANCE FOR IFR/MVFR
LOW STRATUS DEVELOPMENT ACROSS THE WILLAMETTE VALLEY.
KPDX AND APPROACHES...PREDOMINATELY VFR WITH HIGH CLOUDS THROUGH
THE MAJORITY OF THE TAF PERIOD. SHOWERS LINGER THROUGH FRIDAY
MORNING, THEN GRADUALLY DRY UP INTO THE AFTERNOON. VARIABLE
WINDS AROUND 5 KT OR LESS. 20-30% CHANCE FOR IFR/MVFR CIGS
BETWEEN 06-12Z SAT. -10
MARINE
WESTERLY WINDS WILL GRADUALLY EASE FRIDAY TO AROUND
5-10 KT AS LOW PRESSURE WEAKENS. HOWEVER, A STRONG WESTERLY
SWELL WILL MAINTAIN HAZARDOUS SEAS ACROSS THE WATERS INTO FRIDAY
MORNING. THE LATEST OBSERVATIONS AT BUOY 46029 AND 46050 AS OF
EARLY FRIDAY MORNING SHOW SEAS AROUND 15-19 FT AT 13-14 SEC.
THESE SEAS ARE FORECAST TO HOLD THROUGH MID-MORNING FRIDAY
BEFORE GRADUALLY SUBSIDING THROUGHOUT THE DAY. THEREFORE, WENT
AHEAD AND EXTENDED THE HAZARDOUS SEAS WARNING FOR ALL MARINE
ZONES INCLUDING THE COLUMBIA RIVER BAR THROUGH 4 PM FRIDAY.
FOLLOWING THE HAZARDOUS SEAS WARNING, A SMALL CRAFT ADVISORY HAS
BEEN ISSUED ACROSS ALL WATERS INCLUDING THE COLUMBIA RIVER BAR
FROM 4 PM FRIDAY TO 7 AM SATURDAY FOR SEAS AROUND 10-14 FT AT
12-13 SEC. HIGH PRESSURE BUILDS HEADING INTO THE WEEKEND,
MAINTAINING RELATIVELY BENIGN MARINE CONDITIONS WITH WINDS
REMAINING UNDER 15 KT. WINDS DO BEGIN TO TURN MORE EASTERLY ON
SATURDAY AS AN OFFSHORE PRESSURE GRADIENT DEVELOPS. MINIMAL
IMPACTS EXPECTED AS GUIDANCE SUGGESTS A LESS THAN 10% CHANCE FOR
FREQUENT WIND GUSTS GREATER THAN 21 KT AND A >90% CHANCE FOR
SEAS UNDER 10 FT THIS WEEKEND. -10
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...HAZARDOUS SEAS WARNING UNTIL 4 PM PST THIS AFTERNOON FOR PZZ210-
251>253-271>273.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM PST
SATURDAY FOR PZZ210-251>253-271>273.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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