810
FXUS66 KPQR 261047
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
347 AM PDT FRI JUN 26 2026
SYNOPSIS
THE NEXT SEVEN DAYS ARE HIGHLIGHTED BY BELOW AVERAGE
TEMPERATURES FOR THIS TIME OF YEAR WITH PERIODIC CHANCES FOR RAIN
SHOWERS AND A GOOD DEAL OF CLOUD COVER. MOST OF THE SHOWERY ACTIVITY
EXPECTED FROM SUNDAY ONWARD WILL BE FOCUSED OVER THE MOUNTAINS, WITH
THE BULK OF RAIN FALLING IN THE LOWLANDS TODAY THROUGH SATURDAY. NOTE
THERE IS ALSO A 15-25% CHANCE OF THUNDERSTORMS SATURDAY AFTERNOON,
HOWEVER THESE WOULD BE ISOLATED AND SHORT-LIVED WITH MINIMAL IMPACTS
ASIDE FROM BRIEF HEAVY RAIN CAUSING PONDING OF WATER IN LOW-LYING
URBAN AREAS AND THE POTENTIAL FOR A FEW FLASHES OF LIGHTNING.
DISCUSSION...FRIDAY THROUGH THURSDAY NIGHT
MOST LOCATIONS ACROSS
NORTHWEST OREGON AND SOUTHWEST WASHINGTON HAVE OBSERVED ANYWHERE FROM
0.2-0.4 INCHES OF RAIN OVER THE PAST 12-24 HOURS WITH THE PASSAGE OF
A FRONTAL BOUNDARY, WITH SOME AREAS OBSERVING SLIGHTLY BELOW OR ABOVE
THAT RANGE. RADAR OBSERVATIONS FROM EARLY FRIDAY MORNING SHOWED
SCATTERED POST-FRONTAL RAIN SHOWERS ONGOING ACROSS THE AREA, WHILE
SURFACE WEATHER OBSERVATIONS DEPICTED AN OCCLUDED FRONT OVER THE
COASTAL WATERS BEGINNING TO MOVE INLAND. THIS SECONDARY FRONTAL
BOUNDARY IS WEAKER THAN THE FIRST FRONT THAT MOVED THROUGH THE AREA
YESTERDAY INTO LAST NIGHT. THAT SAID, THIS FRONT WILL HELP MAINTAIN
LIGHT RAIN SHOWERS OVER THE AREA TODAY INTO TONIGHT WITH THE MOST
FREQUENT SHOWERS EXPECTED OVER THE MOUNTAINS. GIVEN THE SHOWERY
NATURE OF PRECIPITATION TODAY AND TONIGHT, ADDITIONAL RAIN AMOUNTS
WILL VARY SIGNIFICANTLY FROM LOCATION TO LOCATION, WITH SOME SPOTS
PICKING UP ONLY A FEW HUNDREDTHS OF AN INCH AND OTHERS PICKING UP
OVER 0.25 INCHES. THE LOWEST RAIN AMOUNTS ARE FAVORED IN THE
WILLAMETTE VALLEY TO THE WEST OF THE I-5 CORRIDOR WHERE RAIN
SHADOWING ON THE LEEWARD SIDE OF THE COAST RANGE IS EXPECTED; THESE
AREAS HAVE ONLY A 1-5% CHANCE FOR OVER 0.25 INCHES OF RAIN BETWEEN 5
AM PDT FRIDAY AND 5 AM PDT SATURDAY. MEANWHILE, THE COAST, COASTAL
MOUNTAINS, CASCADES, AND CASCADE FOOTHILLS HAVE A 65-95% CHANCE. WITH
THE EXCESS CLOUD COVER AND SHOWERS IN PLACE TODAY, EXPECT HIGH
TEMPERATURES MAINLY IN THE 60S, EXPECT 50S IN THE CASCADES.
FORECAST RAIN AMOUNTS INCREASE FOR ALL LOCATIONS FROM THE COAST TO
THE CASCADES ON SATURDAY WITH TEMPERATURES REMAINING COOL. THE REASON
RAIN AMOUNTS INCREASE ON SATURDAY IS BECAUSE A CLOSED UPPER LEVEL LOW
CURRENTLY CENTERED OFF THE B.C. COAST WILL BEGIN MOVING DIRECTLY OVER
THE PACIFIC NORTHWEST, BRINGING INCREASING MOISTURE, INSTABILITY, AND
LIFT. FORECAST REFS ENSEMBLE MEAN SOUNDINGS DEPICT STEEPENING
MID-LEVEL LAPSE RATES SATURDAY AFTERNOON WITH SURFACE-BASED CAPE
VALUES INCREASING TO 200-300 J/KG AND EQUILIBRIUM LEVELS INCREASING
CLOSE TO 20,000 FEET. THIS SUGGESTS SOME HEAVIER SHOWERS AND ISOLATED
SHORT-LIVED THUNDERSTORMS WILL BE POSSIBLE, AND NBM THUNDER
PROBABILITIES OF 15-25% BACK THIS UP. GIVEN THE WEAK ENVIRONMENTAL
WIND SHEAR PROFILE IN PLACE, THE MAIN HAZARD WITH STRONGER SHOWERS OR
THUNDERSTORMS WOULD BE BRIEF HEAVY RAIN AND PONDING OF WATER IN
LOW-LYING URBAN AREAS. IT IS ALSO WORTH MENTIONING THAT ISOLATED
NON-MESOCYCLONIC COLD AIR FUNNEL CLOUDS ARE OCCASIONALLY OBSERVED IN
THIS TYPE OF WEATHER PATTERN, HOWEVER THE ROTATION WITH THESE
TYPICALLY FAILS TO LOWER TO THE GROUND AND THUS DAMAGE DOES NOT
OCCUR. IF ROTATION WITH ONE OF THESE WERE TO LOWER TO THE GROUND, IT
WOULD BE CONSIDERED A WEAK LANDSPOUT, AND DAMAGE WITH THESE IS
EXTREMELY ISOLATED IF ANY OCCURS AT ALL. NOTE PROBABILITIES FOR
24-HOUR RAIN AMOUNTS OVER 0.25 INCHES ARE HIGHER ON SATURDAY COMPARED
TO FRIDAY, PEAKING BETWEEN 70-95% ALONG AND EAST OF THE I-5 CORRIDOR
TO THE CASCADE CREST, 30-50% WEST OF THE I-5 CORRIDOR WITHIN THE
WILLAMETTE VALLEY, AND 50-80% FOR THE COAST AND COASTAL MOUNTAINS.
LOCATIONS THAT OBSERVE REPEATED HEAVY SHOWERS COULD SEE OVER 0.5-1.0
INCHES OF RAIN, ESPECIALLY IN THE CASCADE FOOTHILLS.
RAIN AMOUNTS TREND MUCH LIGHTER ON SUNDAY AS THE UPPER LEVEL LOW
SHIFTS EASTWARD INTO IDAHO. HOWEVER, AT LEAST SOME LIGHT SHOWERS WILL
LINGER OVER THE AREA WITH MOIST ONSHORE FLOW ON THE BACKSIDE OF THE
LOW, ESPECIALLY OVER HIGHER TERRAIN. SUNDAY WILL ALSO BE ANOTHER COOL
DAY WITH A GOOD DEAL OF CLOUD COVER AND HIGHS IN THE 60S ACROSS THE
LOWLANDS. COOLER THAN AVERAGE TEMPERATURES AND CHANCES FOR RAIN
SHOWERS ARE IN THE FORECAST MONDAY THROUGH WEDNESDAY AS WELL GIVEN
LITTLE CHANGE TO THE OVERALL WEATHER PATTERN. NOTE MOST OF THE
SHOWERY ACTIVITY NEXT WEEK SHOULD BE CONFINED TO HIGHER TERRAIN. -23
AVIATION
COOL AND MOIST ONSHORE FLOW WILL MAINTAIN CLOUD COVER
AND SCATTERED RAIN SHOWERS ACROSS NORTHWEST OREGON AND SOUTHWEST
WASHINGTON THROUGH 12Z SATURDAY, RESULTING IN A MIXED BAG OF
FLIGHT CONDITIONS. FOR COASTAL LOCATIONS, EXPECT PREDOMINATELY
IFR/LIFR CONDITIONS THROUGH 18Z-20Z FRIDAY WITH CONDITIONS
IMPROVING TOWARDS MAINLY MVFR THEREAFTER. FOR INLAND LOCATIONS
EXPECT A MIXTURE OF MVFR/IFR CONDITIONS, IMPROVING TO HIGH-END
MVFR TO LOW-END VFR AROUND 20-23Z FRIDAY. EXPECT OCCASIONAL DROPS
IN VISIBILITY WITH PASSING SHOWERS, DOWN TO 2-3 SM AT TIMES.
KPDX AND APPROACHES...EXPECT CEILINGS TO RANGE BETWEEN 800-1500
FEET THROUGH 19-20Z FRIDAY BEFORE LIFTING TO 2000-3500 FEET
THEREAFTER. OFF-AND-ON RAIN SHOWERS WILL PERSIST THROUGH 12Z
SATURDAY, RESULTING IN BRIEF DROPS IN VISIBILITY FROM TIME TO
TIME. SURFACE WINDS ARE EXPECTED TO BE OUT OF THE SOUTH TO
SOUTHWEST, SUSTAINED BETWEEN 5-10 KT WITH GUSTS UP TO 15 KT.
-23
MARINE
AN OCCLUDED FRONT OVER THE COASTAL WATERS WAS BEGINNING
TO PUSH INLAND EARLY FRIDAY MORNING, BRINGING AN ABRUPT SHIFT FROM
SOUTHERLY WINDS TO WESTERLY WINDS OVER THE WATERS. BY SUNRISE ON
FRIDAY, WESTERLY WINDS ARE EXPECTED OVER BOTH THE INNER AND OUTER
WATERS WITH GUSTS UP TO 15-20 KT. BUOY OBSERVATIONS FROM EARLY
FRIDAY MORNING REPORTED STEEP WIND-DRIVEN SEAS AROUND 5 TO 7 FT
AND 5 TO 6 SECONDS, STEEPEST OVER THE INNER WATERS WHERE A SMALL
CRAFT ADVISORY REMAINS IN EFFECT THROUGH 5 AM PDT FRIDAY. HOWEVER,
SEAS ARE EXPECTED TO EASE QUICKLY AFTER 5 AM AS WIND SPEEDS
DECREASE BEHIND THE FRONTAL PASSAGE. BUOY 089 BACKS THIS EXPECTATION
UP, REPORTED SEAS OF ONLY 4 FT AT 17 SECONDS. THEREFORE, AN
EXTENSION OF THE AFOREMENTIONED SMALL CRAFT ADVISORY IS NOT
EXPECTED.
WINDS AND SEAS WILL INCREASE AGAIN SATURDAY INTO SUNDAY AS A PAIR
OF FRONTS MOVE SOUTHWARD OVER THE COASTAL WATERS AND PERSISTENT
NORTHWESTERLY WINDS ALLOW FOR THE DEVELOPMENT OF A FRESH NORTHWEST
SWELL UPWARDS OF 7-9 FT AT 9-10 SECONDS, HIGHEST OVER THE OUTER
WATERS BEYOND 10 NM OFFSHORE. GIVEN SEAS WILL BECOME STEEPER
AND WINDS WILL GUSTS UP TO 20-25 KT OVER THE OUTER WATERS, A
SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR THE OUTER WATERS FROM
SATURDAY MORNING THROUGH SUNDAY MORNING.
ALTHOUGH HIGH PRESSURE BUILDS OVER THE WATERS ON MONDAY, NORTHWEST
WINDS WILL PERSIST AND WILL MAINTAIN A FRESH NORTHWEST SWELL WITH
SIGNIFICANT WAVE HEIGHTS PEAKING NEAR AT LEAST 8-10 FT. THERE IS
A 30-40% CHANCE SIGNIFICANT WAVE HEIGHTS WILL PEAK OVER 10 FT
BEYOND 30 NM OFFSHORE ON MONDAY, MAINLY TO THE NORTH OF CAPE
FOULWEATHER. -23
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 5 AM PDT EARLY THIS MORNING FOR
PZZ210-251-252.
SMALL CRAFT ADVISORY FROM 5 AM SATURDAY TO 11 AM PDT SUNDAY FOR
PZZ271>273.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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