767
FXUS66 KPQR 160400 AAA
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
800 PM PST THU JAN 15 2026
UPDATED AVIATION DISCUSSION
SYNOPSIS
HIGH PRESSURE ACROSS THE REGION MAINTAINS DRY
CONDITIONS INTO THE MIDDLE OF NEXT WEEK. WITH INCREASING
EASTERLY FLOW TONIGHT INTO FRIDAY, GUSTY WINDS LIKELY DEVELOP
THROUGH THE CASCADE GAPS, AND ALONG THE COLUMBIA RIVER GORGE
INTO PORTIONS OF THE PORTLAND METRO. EXPECT OVERNIGHT/MORNING
LOW STRATUS AND FOG TO REMAIN LIMITED TO VALLEY AREAS MORE
PROTECTED FROM EAST WINDS LIKE THE SOUTHERN WILLAMETTE VALLEY.
OFFSHORE WINDS DECREASE A TOUCH THE SECOND HALF OF THE WEEKEND
WITH MOSTLY CLEAR SKIES, CHILLY MORNINGS, AND MILD AFTERNOONS,
ALBEIT WITH FOG INCREASING IN COVERAGE.
.DISCUSSION...NOW THROUGH WEDNESDAY NIGHT
AN UNUSUALLY
STRONG AREA OF HIGH PRESSURE WILL REMAIN IN PLACE THROUGH AT
LEAST JAN. 20TH-21ST CONTINUING OUR PROLONGED STRETCH OF DRY
WEATHER. SATELLITE IMAGERY THIS AFTERNOON SHOWS THE LAST
REMNANTS OF LOW STRATUS AND FOG SLOWLY GETTING SCOURED OUT IN
THE SOUTHERLY WILLAMETTE VALLEY AROUND EUGENE WITH CLEAR SKIES
PREVAILING ELSEWHERE. THIS IS THANKS IN-PART TO THE UPPER-
LEVEL RIDGE HAVING RETROGRADED OFF THE WEST COAST WHICH IS
INDUCING AN EASTERLY GRADIENT ACROSS THE CASCADES AND MIXING
THE AIRMASS NEAR THE SURFACE. SO GOING FORWARD EXPECT MAINLY
CLEAR SKIES ACROSS ALL OF NORTHWEST OREGON AND SOUTHWEST
WASHINGTON TO CONTINUE THROUGH AT LEAST TUESDAY OF NEXT WEEK.
THE MAIN EXCEPTION WILL BE THE CENTRAL AND SOUTHERN (MAINLY THE
LATTER) WILLAMETTE VALLEY, WHICH WILL CONTINUE TO SEE CHANCES
FOR FOG AND LOW STRATUS EACH NIGHT. TEMPERATURES EACH DAY WILL
BE CHILLY DURING THE MORNING WITH TEMPERATURES NEAR OR BELOW
FREEZING, AND MILD DURING THE AFTERNOON. HOWEVER, TEMPERATURES
WILL REMAIN MUCH WARMER ABOVE 1000 FT, BOTH OVERNIGHT AND DURING
THE DAY.
HOWEVER WHILE THE EASTERLY FLOW WILL LEAD TO BETTER CLEARING, IT
COMES AS A BIT OF A DOUBLE-EDGED SWORD FOR THOSE NEAR THE
CASCADE GAPS AND COLUMBIA RIVER GORGE WHERE EAST WINDS ARE
ALREADY QUICKLY INCREASING. BOTH DETERMINISTIC AND ENSEMBLE
GUIDANCE ARE CONFIDENT THE SURFACE PRESSURE GRADIENT BETWEEN
KPDX AND KDLS (WHICH CAN BE USED AS A PROXY FOR GAP WIND
STRENGTH) PEAKS AROUND 8-10MB ON FRIDAY WHICH WOULD LIKELY
PRODUCE WINDS BETWEEN 40-55 MPH IN THE TROUTDALE AREA AND OTHER
PORTIONS OF THE FAR EASTERN PORTLAND METRO. ANTICIPATE EVEN
STRONGER GUSTS (55-65MPH+) FOR OUR CLIMATOLOGICALLY WINDIEST
SPOTS LIKE CORBETT, CROWN POINT, THREE CORNER ROCK, ETC. GIVEN
THE HIGH CONFIDENCE IN WIND GUSTS EXCEEDING 45MPH IN THE
TROUTDALE/GRESHAM AREA, PRIMARILY ALONG I-84, HAVE OPTED TO
ISSUE A WIND ADVISORY INTO SATURDAY AFTERNOON FOR THIS FORECAST
ZONE. GUSTS AROUND 30-45MPH LIKELY EXTEND WESTWARD OF I-205 AS
WELL. IT'S WORTH NOTING GIVEN A SLIGHT NORTHERLY COMPONENT TO
THE WINDS ONCE THEY EXIT THE GORGE OPTED TO NOT ADD ZONE WA207
(CAMAS/WASHOUGAL/GREEN MTN) TO THE WIND ADVISORY ALTHOUGH
LOCALIZED GUST AROUND 45MPH ARE CERTAINLY POSSIBLE, ESPECIALLY
IN EASTERN WASHOUGAL. MODELS DEPICT THE GRADIENT WEAKENING
LATER SATURDAY THROUGH SUNDAY WHICH SHOULD REIGN BACK THE EXTENT
OF THE STRONG WINDS, BUT IT WON'T BE UNTIL THE MIDDLE TO END OF
NEXT WEEK WHEN IT TRULY DISSIPATES - WE'LL NEED THE EVENTUAL
PATTERN CHANGE FOR THAT.
SPEAKING OF PATTERN CHANGES, CHANCES FOR RAIN FINALLY RETURN TO
THE AREA LATE WEDNESDAY INTO NEXT THURSDAY, JAN. 21-22, WITH
POPS PEAKING BETWEEN 25-50%. THIS IS WHEN MOST MODEL GUIDANCE
IS SHOWING A TRANSITION BACK TO ONSHORE FLOW AND MORE SEASONABLE
TEMPERATURES. HOWEVER, POPS ARE FAR FROM 100% AS THERE IS STILL
A HANDFUL OF ENSEMBLE GUIDANCE SHOWING VERY LITTLE TO NO
PRECIPITATION AT ALL THROUGH JAN. 23-26. IN OTHER WORDS, IT IS
NOT CLEAR EXACTLY WHEN THIS EXTENDED DRY STRETCH WILL END. ODDS
LEAN ON IT ENDING BY JAN. 23RD, BUT ONLY SLIGHTLY. -99/23
AVIATION
DRY NORTHERLY FLOW ALOFT AS AN UPPER LEVEL RIDGE OF
HIGH PRESSURE SITS JUST OFFSHORE. A STRONG INVERSION REMAINS IN
PLACE WITH COOLER, MOIST AIR NEAR THE SURFACE BELOW THE DRY AND
WARM AIR ALOFT. OFFSHORE WINDS HAVE ALSO INCREASED, ESPECIALLY
THROUGH GAPS IN THE TERRAIN SUCH AS THE COLUMBIA RIVER GORGE.
AREAS INFLUENCED BY THESE WINDS ARE LIKELY TO REMAIN WELL MIXED
AND THUS FOG AND CLOUD FREE. VFR CONDITIONS ARE EXPECTED TO
PERSIST ACROSS THE PORTLAND METRO AREA, AS WELL AS AT THE COAST.
OTHER AREAS MORE PROTECTED FROM THESE WINDS ARE LIKELY TO SEE A
RETURN OF FOG AND/OR STRATUS OVERNIGHT, THOUGH THE NORTHERN
EXTENT REMAINS SOMEWHAT UNCERTAIN. AS OF 03Z, SATELLITE IMAGERY
AND SURFACE OBSERVATIONS ACROSS THE SOUTHERN WILLAMETTE VALLEY
SHOW INCREASING COVERAGE OF DENSE FOG AND LIFR CONDITIONS. EXPECT
THESE CONDITIONS TO PERSIST AT KEUG THROUGH 20Z FRIDAY. THERE ARE
LOWER CHANCES, AROUND 20-30%, FOR IFR CONDITIONS TO SPREAD
NORTHWARD ACROSS PORTIONS OF THE CENTRAL WILLAMETTE VALLEY BY
14-16Z FRIDAY, WITH SIMILAR PROBABILITIES FOR THE TUALATIN VALLEY.
BUT, CONDITIONS ARE LIKELY TO IMPROVE QUICKLY AFTER 20Z FOR MOST
LOCATIONS. THE MAIN EXCEPTION WOULD BE THE SOUTHERN VALLEY WHERE
NORTHERLY, UPSLOPE FLOW MAINTAINS THE MOISTURE THERE. WINDS WILL
BE STRONGEST OF THE COLUMBIA RIVER GORGE, WITH GUSTS UP TO 40 KT
LIKELY, CONTINUING THROUGH FRIDAY EVENING.
KPDX AND APPROACHES...VFR WITH MOSTLY CLEAR SKIES EXPECTED THROUGH
THE PERIOD. SURFACE WINDS AT THE TERMINAL WILL LIKELY REMAIN
RELATIVELY LIGHT, THOUGH GUSTY EAST WINDS MAY MIX DOWN AT TIMES.
WILL MAINTAIN THE MENTION OF LLWS AS EAST WINDS AROUND 40 KT ARE
EXPECTED TO PERSIST BETWEEN 1000-2000 FT MSL. APPROACHES TO THE
EAST ARE MORE LIKELY TO SEE THESE GUSTIER WINDS NEAR THE SURFACE.
EAST WINDS ARE LIKELY TO INCREASE AT THE TERMINAL BY FRIDAY
AFTERNOON. /DH
MARINE
HIGH PRESSURE OVER THE AREA WILL MAINTAIN MORE SETTLED
CONDITIONS THROUGH THE NEXT WEEK. THE THERMAL THROUGH HAS BUILT
OVER THE AREA AND THUS NORTHERLY WINDS HAVE INITIATED. SPEEDS HAVE
BEEN VARIABLE WITH GUSTS UP TO 25 KT OBSERVED EARLIER IN THE DAY,
AND NOW FALLING WELL BELOW 20 KT. DUE TO THE LOCATION OF THE
RIDGE, THE INNER WATERS ARE LESS LIKELY TO EXPERIENCE GUSTS
GREATER THAN 20 KT.
ON FRIDAY, WINDS WILL BECOME EASTERLY AS THE THERMAL TROUGH MOVES
SLIGHTLY OFFSHORE. EXPECT WINDS AROUND 10 TO 20 KT WITH GUSTS UP
TO 25 KT DURING THAT TIME, STRONGEST DOWNWIND OF GAPS IN THE
COASTAL TERRAIN. CONDITIONS HAVE TRENDED MORE MARGINAL IN THE WAY
OF SPEEDS WITH THIS LATEST FORECAST SO CONFIDENCE IN THE EXTENT OF
THESE WIND SPEEDS IS LOW. WINDS REMAIN EASTERLY OVER THE WEEKEND,
ALBEIT MUCH WEAKER IN STRENGTH.
SEAS SHOULD REMAIN BELOW 10 FT THROUGH EARLY NEXT WEEK, BRINGING
A VERY QUIET SEA STATE FOR THIS TIME OF YEAR. -27/23
PQR WATCHES/WARNINGS/ADVISORIES
OR...AIR STAGNATION ADVISORY FROM 7 PM SATURDAY TO 10 AM PST TUESDAY
FOR ORZ109-114>118.
WIND ADVISORY UNTIL 3 PM PST SATURDAY FOR ORZ112.
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 4 PM PST FRIDAY FOR PZZ271.
SMALL CRAFT ADVISORY UNTIL 4 AM PST FRIDAY FOR PZZ272-273.
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