073
FXUS66 KPQR 271219
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
419 AM PST FRI FEB 27 2026
SYNOPSIS
CALM WEATHER CONDITIONS TODAY WITH FOG/FROST IN THE
MORNING. THIS WEEKEND, A WEATHER SYSTEM MOVING INTO NORTHERN
CALIFORNIA WILL BRUSH THE REGION AND RETURN CHANCES FOR
PRECIPITATION, MAINLY FROM SALEM SOUTHWARD. DRY WEATHER RETURNS
EARLY NEXT WEEK BEFORE MORE ANOTHER SYSTEM ARRIVES AND BRINGS
WIDESPREAD PRECIPITATION BY THE MIDDLE OF NEXT WEEK.
DISCUSSION...TODAY THROUGH THURSDAY
SATELLITE IMAGERY AS OF
EARLY FRIDAY MORNING DEPICTS MOSTLY CLEAR SKIES ACROSS NORTHWEST
OREGON AND SOUTHWEST WASHINGTON ASIDE FROM FEW THIN, HIGH
CLOUDS. THESE CLEAR SKIES ARE LEADING TO EFFICIENT RADIATIONAL
COOLING, WITH TEMPERATURES ALREADY NEAR OR SLIGHTLY BELOW
FREEZING ACROSS INTERIOR VALLEYS. COMBINED WITH MOIST SURFACE
CONDITIONS AND LIGHT WINDS, WILL LIKELY SEE WIDESPREAD FROST
AND/OR FOG DEVELOPMENT. DEWPOINT DEPRESSIONS ARE BETWEEN 0-2 DEG
F ACROSS THE WILLAMETTE VALLEY AND SOUTHWEST WA LOWLANDS, SO
WOULDN'T BE SURPRISED TO SEE FOG DEVELOPMENT ALONG THE I-5
CORRIDOR THIS MORNING. A DENSE FOG ADVISORY HAS BEEN ISSUED FOR
THE LANE COUNTY LOWLANDS, WHERE FOG IS ALREADY RESULTING IN
VISIBILITIES OF ONE QUARTER MILE OR LESS. IF YOU WILL BE
COMMUTING IN FOG THIS MORNING, MAKE SURE TO SLOW DOWN AND LEAVE
PLENTY OF DISTANCE BETWEEN YOU AND OTHER VEHICLES. ANY FOG/FROST
THAT DEVELOPS THIS MORNING SHOULD BURN OFF BY AROUND 10 AM-12
PM. CONDITIONS REMAIN DRY TODAY WITH SEASONAL HIGHS IN THE 50S
FOR THE LOWLANDS AS ZONAL FLOW CONTINUES ALOFT.
DETERMINISTIC AND ENSEMBLE GUIDANCE REMAIN IN EXCELLENT
AGREEMENT THAT A CUT-OFF LOW PRESSURE SYSTEM WILL SWING THROUGH
NORTHERN CALIFORNIA FROM THE NORTHEAST PACIFIC DURING THE
SATURDAY AFTERNOON TO EARLY MONDAY MORNING TIME PERIOD. THERE
STILL REMAINS SOME UNCERTAINTY WITH HOW FAR NORTH PRECIPITATION
WILL REACH. THE MAJORITY OF ENSEMBLE MEMBERS (75%) SUGGEST THAT
WRAP-AROUND PRECIPITATION FROM THE SOUTH WILL REACH AT LEAST
THE SOUTHERN-MOST PARTS OF NORTHWEST OREGON BY SATURDAY
AFTERNOON, MAINLY FROM LINCOLN/POLK/MARION COUNTIES SOUTHWARD
BASED ON THE CURRENT LOW TRACK. FOR LOCATIONS NORTH OF THESE
COUNTIES, THERE IS STILL A 50/50 CHANCE FOR EITHER REMAINING
COMPLETELY DRY OR SEEING AT LEAST SOME PRECIPITATION. IF THE LOW
TRACKS FURTHER SOUTH TOWARD THE CENTRAL CA COAST, THEN
NORTHWEST OREGON AND SOUTHWEST WASHINGTON MAY REMAIN COMPLETELY
DRY. IF THE LOW APPROACHES THE COAST CLOSER TO THE CA/OR BORDER,
PRECIPITATION CHANCES COULD SPREAD AS FAR NORTH AS SALEM TO THE
PORTLAND/VANCOUVER METRO AREA. IN ANY CASE, NOT ANTICIPATING
MUCH RAIN NOR IMPACTS FROM THIS SYSTEM. GUIDANCE CURRENTLY
SUGGESTS THAT THE WETTEST SCENARIO (10% CHANCE) IN 24 HOURS IS
AROUND 0.25-0.50 INCH FROM LINCOLN CITY/SALEM SOUTHWARD, AND
0.10-0.25 INCH FOR AREAS TO THE NORTH. SNOW LEVELS WILL ALSO BE
AROUND 6000-7000 FEET, KEEPING SNOWFALL WELL-ABOVE THE CASCADE
PASSES.
THE TEMPERATURE FORECAST WILL ALSO BE IMPACTED BY THE TRACK OF
THIS LOW. THE FARTHER NORTH IT TRACKS, MORE CLOUDS WILL PUSH
NORTH INTO NORTHWEST OREGON AND SOUTHWEST WASHINGTON, LIMITING
DAYTIME WARMING AND NIGHTTIME COOLING. A SOUTHERN TRACK WILL
ALLOW FOR CLEAR SKIES, WARMER DAYTIME TEMPERATURES, AND COLDER
OVERNIGHT TEMPERATURES NEAR TO BELOW FREEZING IN THE INTERIOR
LOWLANDS.
TRANSIENT RIDGING RETURNS TO THE PACNW FOR MONDAY, LEADING TO A
RETURN OF COMPLETELY DRY WEATHER AND WARMER DAYTIME
TEMPERATURES IN THE UPPER 50S. THIS WOULD BE A GREAT DAY TO
SQUEEZE IN OUTDOOR ACTIVITIES BEFORE RAIN CHANCES RETURN ON
TUESDAY AS ANOTHER TROUGH APPROACHES THE REGION. THERE IS STILL
SOME UNCERTAINTY WITH WHEN PRECIPITATION WILL BEGIN, BUT THE
MAJORITY OF ENSEMBLE GUIDANCE (~75%) FAVORS THE DRY WEATHER
COMING TO AN END BY TUESDAY NIGHT INTO WEDNESDAY MORNING. AT
THIS POINT, NO WIND IMPACTS ARE EXPECTED WITH THIS SYSTEM.
HOWEVER, SNOW COULD RETURN TO THE CASCADES AS SNOW LEVELS DROP
TO AROUND 3500-4500 FEET ON WEDNESDAY. CHANCES FOR 6+ INCHES OF
SNOW IN A 48 HOUR PERIOD FROM 4 AM TUESDAY THROUGH 4 AM THURSDAY
ARE AROUND 50-70% ALONG THE SANTIAM AND WILLAMETTE PASSES AND
20% FOR HIGHWAY 26 AT GOVERNMENT CAMP, WITH THE MOST SNOW
FALLING LATE TUESDAY INTO WEDNESDAY. ON THURSDAY, RAIN AND
MOUNTAIN SNOW DECREASE AND TRANSITION INTO LIGHT SHOWERS. -10/03
AVIATION
CLEAR SKIES, MOIST SURFACE CONDITIONS, AND CALM WINDS
ARE RESULTING IN WIDESPREAD FROST AND/OR FOG DEVELOPMENT ACROSS
THE REGION. TERMINAL OBSERVATIONS AS OF EARLY FRIDAY MORNING SHOW
MOSTLY VFR CONDITIONS, EXCEPT FOR THE SOUTHERN WILLAMETTE
VALLEY (KEUG) WHERE DENSE FOG HAS DEVELOPED AND IS RESULTING IN
LIFR VIS/CIGS. EXPECT THE SOUTH VALLEY WILL CONTINUE TRENDING
LIFR THROUGH THE ENTIRE MORNING. FOR LOCATIONS THAT DON'T GET
FOG, FROST WILL BE MORE LIKELY AS TEMPERATURES ARE FALLING INTO
THE LOW 30S. FROST WILL DEVELOP OVER METAL SURFACES AND GRASSES.
THE REST OF THE WILLAMETTE VALLEY HAS A 20-40% CHANCE FOR
LIFR/IFR CIGS AND VIS AT ANY GIVEN HOUR THROUGH 18Z FRI. AFTER
18-19Z FRI, ANY FOG OR FROST THAT DEVELOPED SHOULD DISSIPATE AND
CONDITIONS WILL IMPROVE TO VFR ACROSS ALL TERMINALS. HIGH
PRESSURE WILL SUPPORT MOSTLY SUNNY SKIES THIS AFTERNOON.
VARIABLE WINDS AROUND 5 KT OR LESS THIS MORNING WITH TURN MORE
NORTHERLY IN THE AFTERNOON.
KPDX AND APPROACHES...25-35% CHANCE FOR LIFR/IFR CIGS/VIS THROUGH
18Z FRI. POTENTIAL FOR FROST DEVELOPMENT OVER METAL SURFACES.
OTHERWISE, VFR CONDITIONS WITH MOSTLY SUNNY SKIES TODAY.
NORTHWESTERLY WINDS AROUND 5 KT OR LESS. -10
MARINE
FAIRLY BENIGN CONDITIONS PERSIST ACROSS THE WATERS
EARLY FRIDAY MORNING, WITH SEAS AROUND 6 TO 8 FT. HOWEVER,
SIGNIFICANT WAVE HEIGHTS ARE EXPECTED TO PEAK AROUND 9-10 FT OVER
THE OUTER WATERS FRIDAY MORNING THROUGH THIS EVENING WITH THE
ARRIVAL OF A NORTHWESTERLY SWELL AROUND 8-9 FT AT 14-15 SECONDS.
THEREFORE, A BRIEF SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR THE
OUTER WATERS BEYOND 10 NM OFFSHORE TO COVER THIS TIMEFRAME.
ALTHOUGH SEAS ARE FORECAST TO DECREASE SLIGHTLY FRIDAY NIGHT INTO
SATURDAY, NORTH TO NORTHEASTERLY WINDS WILL BE ON THE INCREASE,
LIKELY PEAKING EARLY SATURDAY MORNING AND AFTERNOON WITH WIND
GUSTS UP TO AROUND 25 KT OVER THE OUTER WATERS AND UP TO 15-20 KT
OVER THE INNER WATERS. AS A RESULT, THE SMALL CRAFT ADVISORY
WAS EXTENDED THROUGH SATURDAY AFTERNOON FOR THE OUTER WATERS SOUTH
OF CAPE FALCON. WINDS WILL EASE ON SUNDAY WHILE BECOMING MORE
EASTERLY, WITH SIGNIFICANT WAVE HEIGHTS DECREASING TO 5 TO 6 FT.
SEAS AND WINDS ARE FORECAST TO DECREASE EVEN MORE MONDAY INTO
TUESDAY BEFORE SMALL CRAFT ADVISORY CONDITIONS LIKELY RETURN ON
WEDNESDAY WITH INCREASING SOUTHERLY WINDS AHEAD OF A FRONTAL
PASSAGE. -10/23
PQR WATCHES/WARNINGS/ADVISORIES
OR...DENSE FOG ADVISORY UNTIL NOON PST TODAY FOR ORZ118.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 10 PM PST THIS
EVENING FOR PZZ271.
SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 4 PM PST SATURDAY
FOR PZZ272-273.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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