361
FXUS66 KPQR 220425 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PORTLAND OR
925 PM PDT SAT MAR 21 2026
UPDATED AVIATION DISCUSSION...
SYNOPSIS
LIGHT RAIN SHOWERS CONTINUE EARLY SATURDAY MORNING,
CLEARING BY 9 AM. DRY WEATHER AND NEAR NORMAL HIGH TEMPERATURES
THROUGH MONDAY WITH MORNING LOW TEMPERATURES IN THE 30S,
PRODUCING WIDESPREAD FROST SATURDAY AND SUNDAY NIGHTS. A WEATHER
SYSTEM BRINGS WIDESPREAD RAIN AND BREEZY WINDS TUESDAY INTO
WEDNESDAY ALONG WITH LIGHT CASCADES SNOW TUESDAY NIGHT INTO
WEDNESDAY. NO SNOW OR FLOODING IMPACTS EXPECTED. DRY WEATHER
RETURNS THURSDAY INTO FRIDAY.
SHORT TERM...NOW THROUGH MONDAY NIGHT
OVERALL, MINIMAL
CHANGES TO THE FORECAST AS MODELS CONTINUE TO HOLD CONSISTENCY
REGARDING ZONAL FLOW THROUGH MONDAY. SATELLITE IMAGERY SHOWS
ONLY A FEW CLOUDS WITHIN THE SOUTHERN WILLAMETTE VALLEY AND HIGH
CLOUDS OVER THE WATERS THIS AFTERNOON. THE CLEARING WILL SET THE
STAGE FOR OVERNIGHT COOLING WHICH IS STILL ON TRACK FOR
DECREASING LOW TEMPERATURES. ENSEMBLES SHOW AROUND A 60-70%
CHANCE OF OVERNIGHT LOWS REACHING 34 DEGREES F FROM SALEM
SOUTHWARD INLAND, AROUND 40% CHANCE IN THE GREATER PORTLAND-
VANCOUVER METRO, AROUND 5% ALONG THE COAST, AND NEARLY 90+% IN
THE UPPER HOOD RIVER VALLEY. WITH THESE TYPES OF TEMPERATURES,
LOW WIND SPEEDS, AND A STABLE ATMOSPHERE OVERNIGHT, FROST IS A
CONCERN. WHILE WE ARE NOT EXPECTING A HARD FREEZE, FOR SENSITIVE
PLANTS FROST MAY BECOME IMPACTFUL. FOG IS ALSO A POSSIBILITY FOR
AREAS THAT REMAIN ABOVE 34 DEGREES F, THOUGH CONFIDENCE IS LOWER
IN HOW WIDESPREAD IT WILL BE. NOTE THAT NWS PORTLAND WILL NOT BEGIN
ISSUING FROST ADVISORIES AND FREEZE WATCHES/WARNINGS FOR
AGRICULTURAL PURPOSES UNTIL APRIL 1ST AS THIS IS WHEN THE
GROWING SEASON BEGINS TO RAMP UP AND IMPACTS FROM FROST AND
FREEZE CONDITIONS BECOME MORE SIGNIFICANT.
SETTLED WEATHER REMAINS THROUGH MONDAY WITH CLOUDS FILLING IN
THROUGH THE AFTERNOON AHEAD OF AN INCOMING FRONT THAT ARRIVES ON
TUESDAY.-27
LONG TERM...TUESDAY THROUGH SATURDAY
A CLOSED LOW PRESSURE
PRESSURE WILL MOVE INTO THE NORTHEAST PACIFIC FROM THE SOUTH
PACIFIC ON TUESDAY USHERING IN WARMER AND MOIST AIR. WIDESPREAD RAIN
AND BREEZY WINDS ARE EXPECTED TO RETURN TUESDAY INTO WEDNESDAY. LATEST
GUIDANCE IS HINTING AT THE POSSIBILITY OF ANOTHER, WEAKER
SURFACE LOW PRESSURE SYSTEM AND ASSOCIATED UPPER LEVEL SHORTWAVE
PUSHING ANOTHER BURST OF RAIN INTO THE REGION LATE WEDNESDAY
INTO THURSDAY MORNING THOUGH THERE IS A LACK OF CONSISTENCY
BETWEEN ENSEMBLE TYPE. FOR EXAMPLE THE GEPS IS SHOWING MORE
MEMBERS WITH PRECIPITATION, WHILE THE ECMWF STAYS NEARLY
UNCHANGED. IT MAY BE THAT THESE TWO INCIDENCES MERGE INTO ONE
CONTINUOUS PATTERN. UNCERTAINTY STILL REMAINS ON EXACT
PRECIPITATION AMOUNTS INTO THURSDAY, THOUGH HIGH CONFIDENCE
REMAINS IN LIMITED FLOODING IMPACTS. BREEZY WINDS ARE ALSO
EXPECTED WITH THE FRONTAL PASSAGE ON TUESDAY. STRONGEST WINDS
WILL BE ALONG THE COAST AND COAST RANGE WHERE THERE IS A 60-70%
CHANCE OF MAXIMUM WIND GUSTS EXCEEDING 40 MPH. INLAND, IT IS
LESS THAN A 20% CHANCE. ONE AREA TO WATCH WILL BE THE CENTRAL
WILLAMETTE VALLEY WHICH TENDS TO SEE HIGHER WINDS WITH THIS
NORTHERLY DIRECTION. THE ALIGNMENT OF THE PRESSURE GRADIENT IS
GOING TO BE A COMPONENT TO CONSIDER.
IN TERMS OF CASCADE SNOW, THE HEAVIEST PRECIPITATION IS
EXPECTED TO FALL AHEAD OF AND ALONG THE COLD FRONT WHEN SNOW
LEVELS ARE GENERALLY HIGHER THAN PASS LEVEL. SNOW LEVELS WILL
FALL QUICKLY AFTER THE FRONT PASSES LATE TUESDAY INTO
WEDNESDAY TO AROUND 3500-4500 FT. HOWEVER, THE LOWEST SNOW
LEVELS WILL BE IN SW WA CASCADES WITH SNOW LEVELS RISING MOVING
SOUTH INTO THE CENTRAL OR CASCADES. AS SHOWERS WILL CONTINUE
INTO WEDNESDAY, THERE IS THE POTENTIAL FOR SOME ACCUMULATING
SNOW, THOUGH DUE TO THE CURRENT SUN ANGLE ALONG WITH WARMER ROAD
TEMPERATURES, IT MIGHT BE DIFFICULT FOR MUCH ACCUMULATION IN
SCATTERED SHOWERS. SNOW LEVELS WILL CONTINUE FALLING THROUGH
WEDNESDAY, ESPECIALLY WEDNESDAY NIGHT, FALLING TO AROUND
2000-3000 FT BY THURSDAY MORNING. THE 10TH PERCENTILE (ONLY 10%
CHANCE OF SNOW LEVELS THIS LOW) DOES INDICATE SNOW LEVELS COULD
FALL AS LOW AS 500-1500 FT BY THURSDAY MORNING. HOWEVER, IF
PRECIPITATION REALLY IS DECREASING BY THIS TIME, THEN THERE WILL
BE LIMITED PRECIPITATION TO EVEN CAUSE SNOW. ONLY A FEW ENSEMBLE
MEMBERS SUGGEST ANY KIND OF ACCUMULATING SNOW IN THE INTERIOR
LOWLANDS LIKE AROUND PORTLAND, AND GENERALLY LESS THAN AN INCH. NBM
PROBABILITIES FOR 6 INCHES OF SNOW OR MORE IN A 48-HOUR PERIOD
ENDING AT 5AM PDT THURSDAY CONTINUE TO BACK THIS EXPECTATION UP,
AS CHANCES ARE ONLY AROUND 5% AT WILLAMETTE AND SANTIAM PASSES,
AND 10% ALONG HIGHWAY 26 NEAR GOVERNMENT CAMP.
BY THURSDAY AFTERNOON INTO FRIDAY, THE WEATHER SYSTEM IS
EXPECTED TO MOVE OUT OF THE AREA WITH UPPER LEVEL FLOW BECOMING
MORE ZONAL. EXPECTING DRY CONDITIONS WITH CLEARING SKIES BY
MIDDAY THURSDAY, WHICH COULD ALLOW FOR TEMPERATURES TO WARM INTO
THE UPPER 50S ON THURSDAY AND RIGHT AROUND 60 ON FRIDAY AND INTO
THE MID 60S ON SATURDAY FOR THE INTERIOR LOWLANDS. IF YOU'RE
SOMEONE WHO LOVES THE WARM WEATHER, PROBABILITIES FOR MAXIMUM
TEMPERATURES OF 70 DEGREES HAVE LINGERED IN THE 20-30% RANGE FOR
THE WILLAMETTE VALLEY. THOUGH, THAT IS STILL QUITE FAR OUT TO
HAVE ANY LEVEL OF CONFIDENCE. BUT, GIVEN THE OVERALL PATTERN,
IT'S NOT OUT OF THE QUESTION. -27/03
AVIATION
AS WE ENTER INTO A ZONAL PATTERN FOR THE ENTIRE TAF
PERIOD, EXPECT DRY WESTERLY FLOW ALOFT AND VFR CONDS THROUGHOUT
THE AIRSPACE. WHILE VFR CONDS WILL PERSIST THROUGH THE TAF PERIOD
THROUGHOUT THE AIRSPACE, A WEAK FRONT WILL MOVE THROUGH WASHINGTON
AROUND 12Z SUN, BRUSHING SOUTHWEST WASHINGTON AND BRINGING LOW-END
VFR CIGS WITH A 10-20% CHANCE OF MVFR CIGS AT KAST BETWEEN 12-18Z
SUNDAY.
CLEAR SKIES TONIGHT WILL SUPPORT TEMPERATURES DROPPING TOWARDS THE
LOW TO MID 30S, RESULTING IN POTENTIAL FROST DEVELOPMENT OVER
METAL SURFACES (GENERALLY AROUND 9-16Z SUN). WINDS REMAIN
NORTHERLY TO NORTHWESTERLY AND UNDER 10 KT THROUGH MOST OF THE TAF
PERIOD. WINDS WILL INCREASE AROUND 18-20Z SUN, RESULTING IN
NORTHERLY WINDS AROUND 8-12 KT AT INTERIOR TERMINALS AND 12 TO 15
KT WITH GUSTS UP TO 21 KT AT COASTAL TERMINALS (HIGHEST CHANCES OF
GUSTS AT KONP).
KPDX AND APPROACHES...VFR CONDS WITH CLEAR SKIES THROUGH THE TAF
PERIOD. NORTHWESTERLY WINDS UNDER 8 KT UNTIL AROUND 18Z SUN, THEN
INCREASING TO AROUND 8-10 KT FOR THE REST OF THE TAF PERIOD.
POTENTIAL FOR WIDESPREAD FROST OVER METAL SURFACES BETWEEN 9-16Z
SUN DUE TO CLEAR SKIES AND CALM WINDS. ~12
MARINE
HIGH PRESSURE OVER THE WATERS WILL MAINTAIN NORTHERLY
WINDS THROUGH MONDAY. THE NEXT VERY STRONG EBB WILL OCCUR AROUND
730 AM SUNDAY, SO A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR THE
THE COLUMBIA RIVER BAR BETWEEN 5-10 AM SUNDAY AS THE EBB BUILDS
SEAS TO AROUND 8 FT ALONG THE MAIN CHANNEL OF THE BAR.
A THERMAL TROUGH DEVELOPS ALONG THE SOUTHERN OREGON COAST SUNDAY
AFTERNOON THROUGH EARLY MONDAY MORNING, TIGHTENING PRESSURE
GRADIENTS ACROSS THE WATERS SOUTH OF CAPE FALCON. THIS WILL LEAD
TO BREEZIER NORTHERLY WINDS WITH GUSTS UP TO 25 KT; THEREFORE, A
SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR ALL WATERS SOUTH OF CAPE
FALCON FROM 2 PM SUNDAY THROUGH AT LEAST 5 AM MONDAY. NORTHERLY
WINDS MAY LAST LONGER FOR THE OUTER WATERS BEYOND 10 NM OFFSHORE,
SO THE SMALL CRAFT ADVISORY FOR THESE ZONES WILL GO THROUGH 8 AM
MONDAY. SEAS FALL TO 5-6 FT TONIGHT, RE-BUILDING TO 8-9 FT AT 11
SEC AS WIND WAVES INCREASE FROM THE BREEZY NORTHERLY WINDS.
THE NEXT ROBUST WEATHER SYSTEM RETURNS TUESDAY INTO WEDNESDAY.
THIS SYSTEM WILL BRING A RETURN OF BREEZY SOUTHERLY WINDS ACROSS
ALL WATERS. CURRENT GUIDANCE SUGGESTS HIGH CONFIDENCE (90%+
CHANCE) FOR WIDESPREAD AND FREQUENT SMALL CRAFT WIND GUSTS OF 21
KT OR GREATER, AND A 35-55% CHANCE FOR WIDESPREAD AND FREQUENT
GALE FORCE WIND GUSTS OF 34 KT OR GREATER ON TUESDAY. CHANCES FOR
ISOLATED GALE FORCE WIND GUSTS ARE AROUND 75-90%, WITH THE HIGHEST
CHANCES BEYOND 20 NM OFFSHORE. LATEST GUIDANCE SUGGESTS THE
STRONGEST WINDS OCCUR BETWEEN 8 AM TO 5 PM TUESDAY. SEAS ON
TUESDAY AND WEDNESDAY ARE ALSO EXPECTED TO BUILD TO AROUND 13-16
FT IN RESPONSE TO INCREASING WIND WAVES ALONG WITH AN INCREASING
WESTERLY SWELL. THERE'S A 30-60% CHANCE SEAS COULD EXCEED 15 FT
WITH A 5-15% CHANCE FOR SEAS EXCEEDING 20 FT. CHANCES INCREASE
FROM SOUTH TO NORTH, PEAKING ACROSS THE WATERS NORTH OF CAPE
FALCON AND MAINLY BEYOND 40 NM OFFSHORE. -10/03
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 5 AM TO 10 AM PDT SUNDAY FOR PZZ210.
SMALL CRAFT ADVISORY FROM 2 PM SUNDAY TO 5 AM PDT MONDAY FOR
PZZ252-253.
SMALL CRAFT ADVISORY FROM 2 PM SUNDAY TO 8 AM PDT MONDAY FOR
PZZ272-273.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
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X.COM/NWSPORTLAND
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