417
FXUS66 KPQR 280503 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PORTLAND OR
1003 PM PDT THU MAR 27 2025
UPDATED AVIATION, MARINE DISCUSSIONS, AND HAZARDS.
SYNOPSIS
ACTIVE WEATHER WILL CONTINUE THROUGH SATURDAY, WITH
COOL, NEAR NORMAL TEMPERATURES AND PERSISTENT SHOWERS ACROSS
THE FORECAST AREA. SATURDAY NIGHT INTO SUNDAY AND BRIEF BREAK IS
EXPECTED IN THE PRECIPITATION. HOWEVER, THIS WILL BE SHORT
LIVED AS A BROAD AREA OF LOW PRESSURE WILL BRING A RETURN OF
RAIN AND LIGHT CASCADE SNOW LATE SUNDAY NIGHT/MONDAY WHICH WILL
PERSIST THROUGH THE MIDDLE OF THE UPCOMING WEEK.
SHORT TERM...NOW THROUGH SUNDAY
SHOWERS CONTINUE THROUGHOUT THE
NEXT FEW DAYS, WITH A LOWER CHANCE OF THUNDERSTORMS THIS AFTERNOON
AND EVENING, AROUND 10-20% CHANCE. WITH MUCH COOLER TEMPERATURES
TODAY (HIGH AROUND 60 TODAY IN THE WILLAMETTE VALLEY AND COLUMBIA
LOWLANDS), AS WELL AS MUCH WEAKER CAPE VALUES AROUND 100-200,
THUNDERSTORMS TODAY WILL BE FAIRLY WEAK IF THEY OCCUR AT ALL, WITH NO
SEVERE IMPACTS EXPECTED. THAT SAID, SHOWERS WILL CONTINUE UNTIL
SATURDAY AS THE LOW OFFSHORE CONTINUES TO SPIN SEVERAL WAVES OF
MOISTURE TOWARDS THE REGION. BETWEEN 5PM THU TO 5PM FRI, THERE IS
AROUND A 75% CHANCE OF QPF EXCEEDING 0.5" FOR ALL INLAND AREAS
(WILLAMETTE VALLEY, SW WASHINGTON). IN THE COAST RANGE AND CASCADES,
EXPECTING CLOSER TO 1-1.5" OF ACCUMULATION DURING THIS PERIOD. THIS
IS ACCOMPANIED BY INCREASINGLY COOL DAYTIME TEMPERATURES, DIPPING
INTO THE MID 50S FRIDAY AND SATURDAY. ADDITIONALLY THE COAST
CONTINUES TO SEE BREEZY SOUTHERLY WINDS UP TO 35 MPH POSSIBLE ON
THURSDAY, THOUGH THIS DECREASES GOING INTO THURSDAY NIGHT. A PERIOD
OF SLIGHTLY STRONGER GUSTS INLAND UP TO 30-35 MPH POSSIBLE INLAND
UNTIL AROUND 6PM IS POSSIBLE AS THE FRONT PUSHES ASHORE, BUT THIS
SHOULD BE BRIEF. WEAKER WINDS EXPECTED AFTERWARDS AS THE FRONT PASSES
THROUGH.
LATE SATURDAY, A BRIEF PATTERN CHANGE IS EXPECTED AS A SHORTWAVE
RIDGE PUSHES INTO THE AREA, WITH DRIER AND SLIGHTLY WARMER ON SUNDAY
BY A FEW DEGREES. THIS IS NOT EXPECTED TO LAST VERY LONG, AS MONDAY
SEES THE NEXT LOW MOVING INTO THE AREA AND BEGINNING TO CREATE COOLER
AND SHOWERY CONDITIONS AGAIN. /JLIU
LONG TERM...MONDAY THROUGH WEDNESDAY
THE NEXT PATTERN CHANGE LOOKS
TO BE LATE SUNDAY/EARLY MONDAY AS TROUGHING RETURNS TO THE AREA. WPC
CLUSTER ANALYSIS SHOWS NEAR UNIVERSAL AGREEMENT IN TROUGHING
CONTINUING THROUGHOUT THE MAJORITY OF THE COMING WEEK, WITH COOL AND
SHOWERY CONDITIONS EXPECTED. NO PARTICULARLY IMPACTFUL RAINFALL IS
EXPECTED AT THE MOMENT, WITH RAIN LOOKING FAIRLY LIGHT. EARLY
ENSEMBLE GUIDANCE SHOWS SNOW LEVELS AROUND 2000-3500 FT, AND MOUNTAIN
SNOW CAN BE EXPECTED AT TIMES THROUGHOUT NEXT WEEK. /JLIU
AVIATION
POST FRONTAL SHOWERS WILL PERSIST WITH STRONGER
SOUTHERLY FLOW. GUSTY SOUTH WINDS PRESENT ALONG THE COAST AND THE
WILLAMETTE VALLEY, WITH THE HIGHEST WIND SPEEDS ALONG COASTAL
TERMINALS. SHOWERS CONTINUE TO BE HEAVY AT TIMES PRODUCING OUTFLOW
WINDS AROUND 30+ KT BUT THOSE ARE NOT THE PREDOMINATE WINDS. HEAVY
RAINFALL WILL REDUCE VISIBILITY. SOME LIGHTNING WAS OBSERVED EARLIER
THIS EVENING BUT HAS NOT BEEN DETECTED SINCE 03Z FRIDAY.
CONTINUE TO USE CAUTION AS THE ENVIRONMENT IS CONVECTIVE, AND WILL
CONTINUE TO SEE AMPLE MIXING. THE FORECAST CHALLENGE WILL BE IN
REGARDS TO CIGS OVER THE NEXT 24 HOURS, AND WHEN THE WINDS BEGIN TO
DECLINE. MODELS HAVE SUGGESTED MVFR CIGS AT THIS POINT IN THE
FORECAST, BUT THAT HAS YET TO MANIFEST. WITH AN OVERCAST MIDLEVEL
CLOUD DECK, IT MAY INSULATE ENOUGH THAT FULL SATURATION AND LOWERING
CLOUDS MAY NOT OCCUR. HOWEVER, A SHORTWAVE OFF THE COAST COULD BRING
IN A SURGE OF COLDER AIR TO CAUSE THOSE CIGS TO DROP TO MVFR LEVELS.
GIVEN THE PATTERN AND THE COOLING THAT WILL INEVITABLY HAPPEN WITH
THE ONSET OF COLDER AIR, HAVE MAINTAINED A PERIOD OF MVFR CIGS AFTER
08Z FRI IN MANY LOCATIONS.
PDX AND APPROACHES...THE MOST DRASTICALLY SHIFTING CONDITIONS HAVE
EASED, BUT GUSTY SOUTH WINDS PERSIST AROUND THE TERMINAL. WINDS AT
2000 FT AGL ARE AROUND 45 KT, AND THROUGH AROUND 18Z FRI. EVEN WITH
THIS DIFFERENCE, WINDS ARE FAIRLY UNIDIRECTIONAL, AND LLWS WILL BE
MORESO RELATED TO THE RUNWAY ORIENTATION THAN TRUE LLWS.
STILL SOMETHING TO BE AWARE OF THOUGH. EXPECTING SHOWERS THOUGH THE
FORECAST PERIOD, BUT LIGHTNING IS NOT EXPECTED.-MUESSLE
MARINE
THE FRONT CONTINUES TO PUSH INLAND TONIGHT BUT WE ARE
CURRENTLY SITTING ON THE BACKSIDE OF THE FRONT. WINDS ARE BEGINNING
TO DECREASE TO 20 TO 25 KT WITH GUSTS UP TO 25 KT. AT BUOY 46029,
WINDS ARE HIGHER THAN CLOSER TO SHORE. WE WILL CONTINUE TO SEE THESE
SPEEDS THROUGH TOMORROW AFTERNOON. SEAS TEMPORARILY PEAKED AT 20 FT
IN THE NORTHERN WATERS, BUT HAVE BEGUN EASING. NOT EXPECTING ANOTHER
SIGNIFICANT RISE THOUGH THEY WILL REMAIN STEEP AND HAZARDOUS INTO
FRIDAY NIGHT. SEAS WILL THEN GRADUALLY SUBSIDE INTO THE LOW TEENS BY
DAYBREAK ON SATURDAY. WEAK HIGH PRESSURE WILL SETTLE OVER THE WATERS
AND RESULT IN LIGHTER WINDS OVER THE WEEKEND, WHICH WILL RESULT IN
SEAS DECREASING FURTHER. A WEAKENING FRONT WILL BRING AN ~70% CHANCE
FOR AT LEAST BRIEF LOW END GALE FORCE WIND GUSTS SOME TIME LATE
SUNDAY OR EARLY MONDAY. GALE FORCE WIND REMAINS OUT OF THE COASTAL
WATERS FORECAST GIVEN UNCERTAINTY IN TIMING. -MUESSLE/CN
BEACH HAZARDS
BEACHGOERS AND THOSE PARTICIPATING IN THE
UPCOMING RAZOR CLAM DIGS SHOULD BE AWARE OF A MODERATE RISK OF
SNEAKER WAVES MOST OF THIS WEEK. BE SURE TO NEVER TURN YOUR BACK TO
THE OCEAN AND KEEP A CLOSE EYE ON INCOMING WAVES, AS SNEAKER WAVES
CAN CATCH BEACHGOERS BY SURPRISE, SOMETIMES RESULTING IN INJURY OR
DEATH. AVOID JETTIES, LARGE LOGS, AND LARGE ROCKS.
ELEVATED SURF CONDITIONS ARE EXPECTED THURSDAY INTO FRIDAY WITH WAVE
HEIGHTS POTENTIALLY EXCEEDING 25 FT, HOWEVER MUCH OF THE SURF ENERGY
WILL BE DIRECTED ALONG-SHORE GIVEN THE SOUTHWESTERLY SWELL
DIRECTION. THIS WILL LIMIT SURF IMPACTS TO AREA BEACHES. FORECAST
SURF ENERGY IS CURRENTLY BELOW CRITERIA FOR THE ISSUANCE OF A HIGH
SURF ADVISORY.
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...GALE WARNING UNTIL 5 PM PDT FRIDAY FOR PZZ210-251>253-271>273.
HAZARDOUS SEAS WARNING FROM 5 PM FRIDAY TO 4 AM PDT SATURDAY FOR
PZZ210-251>253-271>273.
WWW.WEATHER.GOV/PORTLAND
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