163
FXUS66 KPQR 131206 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PORTLAND OR
506 AM PDT TUE OCT 13 2026
...UPDATED PUBLIC, AVIATION, AND WATCHES/WARNINGS/ADVISORIES
SECTIONS...
SYNOPSIS
DRY WEATHER PREVAILS THROUGH THE WEEK. HIGH PRESSURE
STRENGTHENS THURSDAY AND FRIDAY, RESULTING IN MUCH WARMER
TEMPERATURES. OVER THE WEEKEND, COOLER TEMPERATURES AND CHANCES
FOR PRECIPITATION RETURN AS A TROUGH FROM THE GULF OF ALASKA
MOVES TOWARD THE PACIFIC NORTHWEST. CHANCES FOR WIDESPREAD
PRECIPITATION INCREASE FURTHER EARLY NEXT WEEK.
MORNING UPDATE
THE FROST ADVISORY HAS BEEN CANCELLED FOR THE
COAST, COAST RANGE, AND WILLAPA HILLS AS TEMPERATURES REMAIN ABOVE
40 DEGREES. SATELLITE IMAGERY SHOWS HIGH CLOUDS MOVING INTO THE
AREA, WHICH IS PREVENTING FURTHER RADIATIONAL COOLING. GIVEN THAT
THERE ARE OBSERVATIONS REPORTING TEMPERATURES IN THE MID TO UPPER
30S ACROSS THE WILLAMETTE VALLEY, THE FROST ADVISORY REMAINS IN
EFFECT UNTIL 8 AM FOR THIS REGION. THE FREEZE WARNING ACROSS THE
UPPER HOOD RIVER VALLEY ALSO REMAINS IN EFFECT UNTIL 8 AM AS THERE
ARE REPORTS OF TEMPERATURES BETWEEN 28 AND 32 DEGREES. -10
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
SATELLITE IMAGERY
AS OF EARLY TUESDAY MORNING SHOWS HIGH LEVEL CLOUDS MOVING INTO
NORTHWEST OREGON AND SOUTHWEST WASHINGTON AHEAD OF A SYSTEM
THAT'S MOVING INTO BRITISH COLUMBIA. CLEAR SKIES AND CALM WINDS
EARLIER THIS EVENING HAVE ALLOWED FOR EFFICIENT RADIATIONAL
COOLING; HOWEVER, THE INCREASING CLOUD COVER MAY LIMIT FURTHER
COOLING THIS MORNING. FOR NOW, FROST ADVISORIES REMAIN IN EFFECT
ACROSS MOST AREAS WEST OF THE CASCADES FOR LOW TEMPERATURES OF
33 TO 36 DEGREES RESULTING IN FROST DEVELOPMENT, AND A FREEZE
WARNING FOR THE UPPER HOOD RIVER VALLEY FOR SUB-FREEZING
TEMPERATURES OF 28 TO 32 DEGREES. ANYONE GROWING OUTDOOR
PLANTS THAT ARE SUSCEPTIBLE TO FROST DAMAGE SHOULD CONTINUE TO
COVER PLANTS OR LEAVE PLANTS INDOORS IF POSSIBLE. TEMPERATURES
WILL BE MONITORED OVER THE NEXT FEW HOURS, AND IF HIGH CLOUD
COVER PREVENTS TEMPERATURES FROM FALLING INTO THE LOW TO MID
30S, THE FROST ADVISORY AND/OR FREEZE WARNING MAY BE CANCELLED.
DRY CONDITIONS PREVAIL TODAY AND WEDNESDAY AS MUCH OF OUR AREA
REMAINS UNDER AN UPPER-LEVEL RIDGE. THIS RIDGE FLATTENS OUT A
BIT TODAY DUE TO THE SYSTEM MOVING INTO BRITISH COLUMBIA, BUT
PRECIPITATION IS GENERALLY EXPECTED TO REMAIN WELL-NORTH OF OUR
AREA. AN EXCEPTION WOULD BE THE SOUTH WASHINGTON COAST, WHERE
THERE IS A 15% CHANCE FOR LIGHT SHOWERS TONIGHT. THE THREAT FOR
FROST DECREASES TONIGHT AS INCREASING CLOUD COVER KEEPS
WEDNESDAY MORNING LOW TEMPERATURES SLIGHTLY WARMER THAN THE LAST
FEW NIGHTS. -10
LONG TERM...THURSDAY THROUGH MONDAY
ENSEMBLES REMAIN IN
AGREEMENT THAT UPPER-LEVEL RIDGING WILL AMPLIFY OVER THE PACIFIC
NORTHWEST THURSDAY AND FRIDAY, RESULTING IN TEMPERATURES
REBOUNDING TO THE MID TO UPPER 70S ACROSS INTERIOR VALLEYS AT
THE END OF THE WEEK. GUIDANCE ALSO SUGGESTS THAT THERMAL
TROUGHING WILL ALSO SET-UP OVER WESTERN OREGON, RETURNING
OFFSHORE EASTERLY FLOW ACROSS THE CASCADES AND COLUMBIA RIVER
GORGE BEGINNING WEDNESDAY NIGHT AND LASTING THROUGH FRIDAY
MORNING. WHILE THE GORGE REMAINS GUSTY THE ENTIRE TIME DUE TO
GAP-DRIVEN WINDS, OFFSHORE FLOW OVER THE CASCADES WILL FOLLOW A
DIURNAL PATTERN OF INCREASING WINDS OVERNIGHT AND WEAKENING IN
THE AFTERNOON. THE STRONGEST WINDS ARE EXPECTED ON THURSDAY,
WHERE THERE IS A 20-30% CHANCE FOR PEAK WIND GUSTS EXCEEDING 40
MPH THROUGH THE GORGE AT RIVER-LEVEL, AND A 20-40% CHANCE FOR
PEAK WIND GUSTS UP TO 50-55 MPH FOR EXPOSED RIDGETOPS WITHIN
HIGHER TERRAIN SURROUNDING THE GORGE (I.E. THREE CORNER ROCK).
OFFSHORE WINDS REMAIN WEAKER ACROSS THE CASCADES, WITH A 20-40%
CHANCE FOR PEAK WIND GUSTS EXCEEDING 30 MPH ALONG THE CREST AND
EXPOSED RIDGETOPS OF THE FOOTHILLS.
OVER THE WEEKEND, THE MAJORITY OF ENSEMBLE MEMBERS CONTINUE TO
FAVOR AN UPPER-LEVEL TROUGH MOVING SOUTHEASTWARD FROM THE GULF
OF ALASKA AND PUSHING THE RIDGE EASTWARD. WHILE THERE IS STILL
UNCERTAINTY WITH THE TIMING, STRENGTH, AND PLACEMENT OF THE
TROUGH, THERE IS HIGH CONFIDENCE THAT WE'LL SEE COOLER
TEMPERATURES AND INCREASING CHANCES FOR PRECIPITATION THIS
WEEKEND. CHANCES FOR AT LEAST 0.25 INCH OF LIQUID PRECIPITATION
FROM 5 AM SATURDAY TO 5 AM MONDAY ARE AROUND 30-45% ALONG THE
ALONG THE COAST, COAST RANGE, AND WILLAPA HILLS, AND 15-30%
ALONG THE I-5 CORRIDOR AND CASCADES. BY MONDAY, MOST ENSEMBLE
MEMBERS SUGGEST THAT THE TROUGH WILL ENTER THE PACIFIC
NORTHWEST, BRINGING INCREASED CHANCES FOR MORE WIDESPREAD
PRECIPITATION. -10
AVIATION...THROUGH 12Z WEDNESDAY
SATELLITE IMAGERY AND TERMINAL
OBSERVATIONS AS OF EARLY TUESDAY MORNING DEPICTS HIGH CLOUDS MOVING
INTO NORTHWEST OREGON AND SOUTHWEST WASHINGTON AS A WEAK SYSTEM
MOVES INTO BRITISH COLUMBIA TODAY. GIVEN THAT THIS SYSTEM IS FURTHER
NORTH, PRECIPITATION IS NOT EXPECTED ACROSS OUR AREA AND WILL
CONTINUE TO HAVE VFR CONDITIONS WITH MID TO HIGH LEVEL CLOUDS
THROUGHOUT THE TAF PERIOD. AN EXCEPTION WOULD BE KAST, WHERE THERE
IS A 20-40% CHANCE FOR MVFR CIGS OR LOWER AT ANY GIVEN HOUR AFTER 00-
03Z WED. LIGHT NORTHWESTERLY OR VARIABLE WINDS AROUND 5 KT OR LESS
TODAY ACROSS ALL TERMINALS.
TEMPERATURES IN THE MID 30S ACROSS THE SOUTHERN WILLAMETTE VALLEY
THIS MORNING MAY RESULT IN FROST DEVELOPMENT OVER METAL SURFACES.
THE THREAT FOR FROST DECREASES AFTER 8 AM AS TEMPERATURES WARM UP.
KPDX AND APPROACHES...VFR WITH MID TO HIGH LEVEL CLOUDS THROUGH THE
TAF PERIOD. NORTHWESTERLY WINDS UNDER 5 KT TODAY. -10
MARINE
BENIGN MARINE CONDITIONS EXPECTED THIS WEEK. TODAY AND
WEDNESDAY, LIGHT WINDS TURN MORE SOUTHERLY FROM A WEAK FRONT,
THEN RETURN NORTHERLY BY THE END OF THE WEEK. SEAS REMAIN AROUND
4-6 FT THIS WEEK WITH PERIODS OF 13-15 SECONDS THROUGH WEDNESDAY
AND 11-13 SECONDS LATE THIS WEEK. A STEEPER NORTHWESTERLY SWELL
ARRIVES THIS WEEKEND, BUILDING SEAS TO 7-9 FT BY SUNDAY AND 9-11
FT EARLY NEXT WEEK. THERE IS A 10-30% CHANCE FOR SEAS EXCEEDING 13
FT ON MONDAY, WITH THE HIGHEST CHANCES OVER THE WATERS BEYOND
30-40 NM. WILL ALSO NOTE THAT THE LONG PERIODS FROM THE SWELLS
THIS WEEK WILL RESULT IN A MODERATE SNEAKER WAVE THREAT. CAUTION
SHOULD BE USED WHEN IN OR NEAR THE WATER. -10
PQR WATCHES/WARNINGS/ADVISORIES
OR...FROST ADVISORY UNTIL 8 AM PDT THIS MORNING FOR ORZ109-112>119-
123>125.
FREEZE WARNING UNTIL 8 AM PDT THIS MORNING FOR ORZ121.
WA...FROST ADVISORY UNTIL 8 AM PDT THIS MORNING FOR WAZ205>208.
PZ...NONE.
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