094
FXUS66 KPQR 161810 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PORTLAND OR
1110 AM PDT MON MAR 16 2026
UPDATED AVIATION DISCUSSION.
SYNOPSIS
MOSTLY DRY WEATHER THIS WEEK AS AN UPPER LEVEL
RIDGE BUILDS OVER THE AREA. THIS RIDGE WILL RESULT IN SPRING-
LIKE TEMPERATURES THIS WEEK WITH HIGHS IN THE MID 60S TO LOW 70S
ACROSS INTERIOR VALLEYS. HOWEVER, TUESDAY THROUGH THE END OF
THE WEEK, MOISTURE RIDING THE NORTHERN PERIPHERY OF THE RIDGE
WILL RETURN CHANCES FOR PRECIPITATION, WITH THE HIGHEST CHANCES
ACROSS SOUTHWEST WASHINGTON AND THE OREGON COAST NORTH OF
TILLAMOOK, BUT THE BULK OF THE RAIN IS FORECAST TO TRACK TOWARD
WESTERN BRITISH COLUMBIA AND NORTHWEST WASHINGTON, WITH LIGHTER
AMOUNTS OVER OUR AREA.
DISCUSSION...NOW THROUGH SATURDAY
AN UPPER LEVEL RIDGE
BUILDING OVER THE EASTERN PACIFIC OCEAN, AND MOISTURE FROM AN
ATMOSPHERIC RIVER (AR) ARE THE TWO PREDOMINANT SYNOPTIC
FEATURES THIS WEEK. THE RIDGE BUILDING UP FROM THE SOUTH IS
PUSHING THE AR NORTHWARD, WHICH IS RESULTING IN THE BULK OF THE
PRECIPITATION RIDING THE NORTHERN EDGE OF THE RIDGE AND FORCING
THE MAJORITY OF THE PERCEPTION TOWARDS THE OLYMPIC PENINSULA
AND VANCOUVER ISLAND.
THE CENTER OF THIS UPPER LEVEL RIDGE WILL MOVE INLAND AROUND
SOUTHERN CALIFORNIA, WITH THE RIDGE AXIS PUSHING INTO OUR CWA
TODAY. THIS WILL BRING GENERALLY DRY WEATHER AND DECREASING
CLOUD COVER OVER OUR FORECAST AREA, WITH THE FURTHER SOUTH YOU
GO, THE MORE SUNNY/BLUE SKIES YOU'LL SEE. THE MOISTURE RIDING
THE RIDGE MAY KEEP SOME SCATTERED/BROKEN CLOUD COVER AROUND
LONGER FOR AREAS NORTH OF SALEM AND TILLAMOOK. ABOVE-AVERAGE
500 MB HEIGHTS WILL ALSO SET-UP OVER THE AREA, RESULTING IN A
WARMER AIR MASS AND HIGH TEMPERATURES IN THE MID TO UPPER 60S
ACROSS INTERIOR VALLEYS. SOME PLACES LIKE THE SOUTHERN WILLAMETTE
VALLEY MAY EVEN EXCEED 70 DEGREES (60-80% CHANCE) GIVEN THE
LACK OF CLOUD COVER AND GREATER MAGNITUDE OF HIGH PRESSURE.
AS THE RIDGE GRADUALLY SHIFTS EASTWARD ON TUESDAY, THE RIDGE
ITSELF WILL DEFORM SLIGHTLY AND AS IT DOES, THE AFOREMENTIONED
AR THAT'S RIDING THE RIDGE WILL SHIFT A BIT FURTHER SOUTH. WHILE
THE BULK OF THE RAIN FROM THIS AR WILL CONTINUE TO BE DIRECTED
TOWARDS THE OLYMPIC PENINSULA AND VANCOUVER ISLAND, THE
SOUTHERN PERIPHERY OF THE AR WILL BRING PRECIPITATION BACK INTO
THE FORECAST FOR THE MAJORITY OF THE CWA. THE HIGHEST CHANCES
(60-80%) FOR RAIN WILL BE ACROSS SOUTHWEST WASHINGTON AND ALONG
THE COAST FROM TILLAMOOK NORTHWARD. FROM WEDNESDAY TO FRIDAY,
THE UPPER RIDGE REMAINS SETTLED OVER THE SOUTHERN PORTION OF THE
GREAT BASIN WITH MINIMAL WEAKENING OR EASTWARD MOVEMENT. THIS
WILL MAINTAIN PRECIPITATION CHANCES OVER SOUTHWEST WASHINGTON
AND FAR NORTHWEST OREGON THROUGH THE END OF THE WEEK AS MOISTURE
CONTINUES TO TREK ALONG THE BACKSIDE OF THE RIDGE.
PRECIPITATION AMOUNTS LOOK LIGHT, RESULTING IN NEGLIGIBLE
IMPACTS TO OUR AREA. CHANCES FOR 24 HOUR RAIN EXCEEDING 1 INCH
EACH DAY THIS WEEK ARE AROUND 25-40% ALONG THE NORTH OREGON AND
SOUTH WASHINGTON COASTS, AND LESS THAN 10% EVERYWHERE ELSE.
THUS, CHANCES FOR RIVER FLOODING OVER THE NEXT 10 DAYS REMAIN
UNDER 5%. HOWEVER, THERE ARE A FEW MODEL SOLUTIONS THAT SUGGEST
THAT THE HIGH PRESSURE COULD WEAKEN SIGNIFICANTLY OR TREK FURTHER
SOUTHWARD AND EITHER OF THOSE TWO SCENARIOS WOULD RESULT IN THE
AR DROPPING FURTHER SOUTHWARD. IF THIS WERE TO OCCUR, THEN WE
COULD RECEIVE EVEN MORE RAIN. IN THIS CASE, THE WETTEST
SCENARIOS FOR 24 HOUR RAIN EACH DAY FROM WEDNESDAY THROUGH
SATURDAY (10% CHANCE OF OCCURRING) WOULD BE AROUND 1.10-1.75
INCHES ALONG THE COAST, COAST RANGE AND THE CASCADES, WITH
0.30-0.80 INCHES ALONG THE I-5 CORRIDOR. THE HIGHEST TOTALS
WOULD BE OBSERVED FOR AREAS NORTH OF SALEM, OR.
DESPITE THE RENEWED PRECIPITATION CHANCES THIS WEEK, SPRING-LIKE
TEMPERATURES IN THE 60S AND POTENTIALLY LOW 70S WILL CONTINUE
ACROSS INTERIOR VALLEYS THROUGH FRIDAY, WITH THE WARMEST DAYTIME
HIGHS EXPECTED SOUTH OF SALEM, OR. CHANCES FOR EUGENE EXCEEDING
75 DEGREES F ARE AROUND 20-40% FROM WEDNESDAY TO THE END OF THE
WEEK. GIVEN THE WARMER, TEMPERATURES WE COULD SEE INCREASED
SNOWMELT ACROSS THE CASCADES. SNOW LEVELS WILL BE ABOVE 7000-8000
FEET, SO ANY PRECIPITATION THAT FALLS OVER THE CASCADE PASSES
WILL BE RAIN. BY SATURDAY, MOST ENSEMBLE GUIDANCE (70-80%)
SUGGESTS THE RIDGE WILL BEGIN TO BREAK DOWN AND RESULT IN ZONAL
FLOW ACROSS THE PACIFIC NW. THIS PATTERN CHANGE WILL BRING
COOLER TEMPERATURES, WITH DAYTIME HIGHS IN THE UPPER 40S TO
UPPER 50S ACROSS THE FORECAST AREA. /42-10
AVIATION
A BROAD UPPER LEVEL RIDGE WITH MID-LEVEL MOISTURE WILL
MAINTAIN WEST TO NORTHWEST FLOW ALOFT ALONG WITH MID TO HIGH LEVEL
CLOUDS STREAMING ACROSS THE AREA. EXPECT WIDESPREAD VFR CONDITIONS
TO CONTINUE THROUGH THE PERIOD AT MOST TERMINALS. CONDITIONS ALONG
THE COAST MAY DROP TO MVFR WITH A 30-50% CHANCE OF MVFR CIGS ANY
GIVEN HOUR THROUGH THE EVENING. PROBABILITIES INCREASE TONIGHT AS
A WEAK FRONT SAGS TOWARDS THE AREA. MVFR CONDITIONS HAVE A 70% OR
GREATER CHANCE OF OCCURRING AND A 30-50% OF IFR CONDITIONS.
SOUTHERLY WINDS 5-10 KT EXPECTED THROUGH THE TAF PERIOD.
KPDX AND APPROACHES...MAINLY VFR CONDITIONS EXPECTED WITH
SOUTHERLY WINDS 5-10 KTS. LIGHT RAIN SHOWERS MOVE IN LATE TONIGHT
ALONG WITH A LOW (10%) CHANCE OF MVFR CONDITIONS. -19
MARINE
SOUTHERLY WINDS ARE EXPECTED ACROSS ALL WATERS AND
WILL TO INCREASE TODAY WITH GUSTS UP TO 25 KT, THE STRONGEST
GUSTS ARE EXPECTED ACROSS THE NORTHERN COASTAL WATERS. SEAS WILL
ALSO BUILD TODAY IN RESPONSE TO THE INCREASING WIND WAVES AND
SOUTHWESTERLY SWELL, THIS WILL RESULT IN SEAS BUILDING TOWARDS 8
TO 11 FT WITH THE HIGHEST SEAS IN THE NORTHERN AND CENTRAL
WATER ZONES. BREEZY SOUTHERLY WINDS CONTINUE THROUGH AT LEAST
MID-WEEK AS A QUASI- STATIONARY FRONT REMAINS OFFSHORE. WINDS
ARE EXPECTED TO INCREASE ON THURSDAY WITH AROUND A 30% CHANCE OF
GUSTS UP TO 25 KT ACROSS THE NORTHERN AND CENTRAL WATERS AS THE
FRONT PUSHES INLAND TOWARDS THE END OF THE WEEK. AS THE FRONT
MOVES IN, EXPECT WINDS TO BECOME NORTHERLY, WHICH WILL PERSIST
THROUGH THE WEEKEND. /42
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 5 AM PDT
WEDNESDAY FOR PZZ210-251-252-272.
SMALL CRAFT ADVISORY UNTIL 5 AM PDT WEDNESDAY FOR PZZ271.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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