017
FXUS66 KPQR 052222
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
322 PM PDT TUE MAY 5 2026
SYNOPSIS
UPPER LEVEL HIGH PRESSURE REMAINS THE CONTROLLING
FEATURE THIS LATE AFTERNOON, KEEPING THE OVERALL PATTERN DRY AND
WARMER THAN NORMAL THROUGH THURSDAY. EACH NIGHT WILL STILL
BRING A MARINE SURGE, CLOUDS EXPANDING ACROSS THE COAST AND
PUSHING INLAND THROUGH GAPS, FOLLOWED BY PARTIAL TO SUBSTANTIAL
CLEARING DURING THE DAY. THE NEXT PERIOD TO WATCH IS FRIDAY INTO
SATURDAY, WHEN A WEAK DISTURBANCE UNDERCUTS THE RIDGE AND
BRINGS A MODEST COOL-DOWN PLUS VERY LOW-END RAIN CHANCES (MAINLY
COAST AND HIGHER TERRAIN NORTH OF A LINE FROM LINCOLN CITY TO
SALEM). RIDGING IS FAVORED TO REBOUND LATE THIS WEEKEND,
RETURNING THE REGION TO WARMER AND DRY WEATHER FOR SUNDAY INTO
EARLY NEXT WEEK, WITH SOME POTENTIAL FOR 80 DEGREES ALONG PARTS
OF THE I-5 CORRIDOR.
DISCUSSION...NOW THROUGH TUESDAY
THE BIG PICTURE HASN'T
CHANGED SINCE THIS MORNING: BROAD RIDGING HOLDING FIRM OVER THE
NORTHEAST PACIFIC INTO THE PACIFIC NORTHWEST, AND IT'S KEEPING
MEANINGFUL PRECIPITATION AT BAY. THE DAY TO DAY WEATHER
CONTINUES TO BE SHAPED BY MARINE AIR NEAR THE SURFACE RATHER
THAN ANY NEARBY STORMS. EXPECT THE COAST TO STAY COOLEST WITH
LINGERING LOW CLOUDS AT TIMES AND OCCASIONAL LATE-NIGHT/EARLY-
MORNING MIST OR DRIZZLE, WHILE INTERIOR VALLEYS SPEND MORE TIME
DRY WITH AFTERNOON SUNSHINE ONCE THE MORNING CLOUD LAYER
RETREATS.
FROM TONIGHT THROUGH THURSDAY, PLAN ON A SIMILAR REPEATED CYCLE
COMPARED TO PREVIOUS DAYS. LOW CLOUDS EXPAND INLAND OVERNIGHT,
ESPECIALLY THROUGH THE COAST RANGE GAPS AND INTO THE WILLAMETTE
VALLEY, THEN GRADUALLY ERODE BACK TOWARD THE COAST LATE MORNING
INTO AFTERNOON. HOW QUICKLY THAT BURN-OFF HAPPENS WILL STILL BE
THE MAIN DRIVER OF TEMPERATURES EACH DAY. IF CLEARING IS
QUICKER, INLAND HIGHS WILL PUSH TOWARD THE UPPER 70S; IF CLOUDS
HANG ON LONGER, MID TO UPPER 60S BECOMES MORE LIKELY. ALONG THE
COAST AND HIGHER TERRAIN, HIGHS GENERALLY HOLD IN THE UPPER 50S
TO UPPER 60S. HEAT IMPACTS REMAIN LIMITED FOR MOST, WITH THE
MAIN CONCERN CONFINED TO THOSE VERY SENSITIVE TO WARMER
TEMPERATURES.
ATTENTION THEN SHIFTS TO LATE FRIDAY AND SATURDAY. ENSEMBLE
GUIDANCE CONTINUES TO CLUSTER AROUND A SHORTWAVE DISTURBANCE
SLIDING OVER THE TOP OF THE RIDGE AND KNOCKING TEMPERATURES BACK
CLOSER TO SEASONAL LEVELS. MOISTURE WITH THIS FEATURE LOOKS
LIMITED, SO RAIN CHANCES STAY ON THE VERY LOWER SIDE, HIGHEST AT
THE COAST AND ACROSS HIGHER TERRAIN, MAINLY NORTH OF A LINE
FROM LINCOLN CITY TO SALEM (ROUGHLY 15-25%). THE REST OF THE
AREA HAS PROBABILITIES LESS THAN 10%. EAST OF THE CASCADES,
INCLUDING THE UPPER HOOD RIVER VALLEY AND THE CENTRAL GORGE,
RAIN CHANCES REMAIN NEAR ZERO (UNDER 5%). IF RAIN DOES DEVELOP,
THE MOST LIKELY SCENARIO BRINGS SHOWERS TO THE COAST SOMETIME
FRIDAY AFTERNOON AND EVENING, THEN NUDGING INLAND WITHIN A FEW
HOURS. AMOUNTS LOOK LIGHT WHERE IT DOES RAIN, GENERALLY UNDER A
TENTH OF AN INCH. IN GENERAL, THERE IS LOWER CONFIDENCE FOR
PRECIPITATION AS RECENT MODEL GUIDANCE HAS TRENDED DRIER.
BY LATE WEEKEND INTO MONDAY, THE BROADER SIGNAL RETURNS TO
REBUILDING RIDGING AND ANOTHER WARM-UP. SUNDAY CURRENTLY LOOKS
LIKE THE BETTER DAY FOR WARMER TEMPERATURES, WITH PROBABILITIES
FOR 80 DEGREES ALONG THE I-5 CORRIDOR AROUND 35-70%, HIGHEST
WITHIN THE PORTLAND-VANCOUVER METRO. CONFIDENCE IN THE WARM/DRY
TREND IS BETTER THAN THE DETAILS OF EXACTLY HOW WARM EACH INLAND
VALLEY GETS, WHICH WILL STILL DEPEND ON HOW FAR INLAND MORNING
CLOUDS MANAGE TO REACH AND HOW QUICKLY THEY CLEAR. TUESDAY
CONTINUES TO SUPPORT THE COOLING TREND, WITH ZONAL ALOFT AND
HIGH PRESSURE AT THE SURFACE OVER THE NORTHEAST PACIFIC.
~12
AVIATION
AT 22Z TUESDAY, AN EXPANSIVE MARINE STRATUS DECK
REMAINED FIRMLY IN PLACE ACROSS THE WILLAMETTE VALLEY AND ALONG
THE COAST. HOWEVER, SATELLITE OBSERVATIONS SHOWED THE EDGES OF
MARINE STRATUS DECK BEGINNING TO ERODE WITH BREAKS IN CLOUD COVER
BEGINNING TO SHOW UP. THIS SUGGESTS THIS LOW STRATUS DECK IS STILL
ON TRACK TO SCATTER OUT SOMETIME BETWEEN 23Z TUESDAY AND 00Z
WEDNESDAY, GIVING WAY TO VFR FLIGHT CONDITIONS FOR THE REMAINDER
OF THE DAY. ONE POTENTIAL EXCEPTION IS AT THE COAST, WHERE THERE
IS A 40-50% CHANCE MARINE STRATUS WILL REMAIN IN PLACE THROUGH
THE REST OF TODAY AND INTO TONIGHT. THERE IS ALSO AROUND A 10%
CHANCE LOW CLOUDS WILL FAIL TO SCATTER OUT AT INLAND TAF SITES BY
00Z WEDNESDAY, HOWEVER CURRENT SATELLITE OBSERVATIONS SUGGEST THIS
WILL MOST LIKELY NOT OCCUR.
FOR INLAND AREAS WHERE CLEARING SKIES IS MORE LIKELY TO OCCUR,
EXPECT LOW CLOUDS TO FILL BACK IN QUICKLY THIS EVENING INTO EARLY
TONIGHT (MOST LIKELY BETWEEN 06-09Z WEDNESDAY). THIS WILL RESULT
IN ANOTHER ROUND OF PERSISTENT MVFR CIGS INLAND. ONGOING MVFR CIGS
AT THE COAST WILL LIKELY LOWER TO IFR TONIGHT, EVEN IF MVFR CIGS
DO BRIEFLY SCATTER OUT TOWARDS 00Z WEDNESDAY. WINDS ARE EXPECTED
TO REMAIN LIGHT AND VARIABLE AROUND 5 KT OR LESS THROUGH THE 00Z
TAF PERIOD.
KPDX AND APPROACHES...LIGHT AND VARIABLE WINDS AROUND 5 KT OR LESS
WILL PERSIST THROUGH 00Z WEDNESDAY. LOW STRATUS WITH CIGS AROUND
3000 FT REMAINS IN PLACE AS OF 22Z TUESDAY, HOWEVER THE ONGOING
CLOUD COVER IS STILL ON TRACK TO SCATTER OUT BY APPROXIMATELY 00Z
WEDNESDAY BEFORE QUICKLY RETURNING SOMETIME BETWEEN 05-10Z
WEDNESDAY. NOTE THERE IS A 10% CHANCE ONGOING LOW CLOUDS WILL FAIL
TO SCATTER OUT LATE THIS AFTERNOON. IF THIS WERE TO OCCUR, MVFR
CIGS WOULD PERSIST NOW THROUGH AT LEAST WEDNESDAY MORNING. -23
MARINE
A CONTINUED SOUTHERLY SURGE WILL BRING PERSISTENT LOW
STRATUS THROUGH WEDNESDAY WITH CHANCES FOR FOG AND/OR DRIZZLE
DURING THE OVERNIGHT AND MORNING HOURS. SOUTHERLY WINDS AROUND
5-10 KT THIS MORNING WILL TURN WESTERLY AND WEAKEN TO 5 KT OR
LESS THIS AFTERNOON INTO TONIGHT. WINDS LOOK TO TURN NORTHERLY
LATE WEDNESDAY THROUGH MUCH OF THURSDAY, BEFORE A WEAK SYSTEM
MOVING ONSHORE FRIDAY INTO SATURDAY WILL SEE SOUTHERLY FLOW
RETURN WITH GUSTS OF 15-20 KT AND LOW CHANCES FOR RAIN SHOWERS.
HIGH PRESSURE REBUILDING THIS WEEKEND WILL YIELD STRENGTHENING
NORTHERLY FLOW, WHICH MAY BECOME HAZARDOUS TO SMALL CRAFT LATE
SUNDAY INTO MONDAY WITH GUSTS UP TO 20-25 KT. CHANCES FOR GUSTS
TO REACH 21 KT OR HIGHER INCREASE SLIGHTLY FROM 50-80% ON
SUNDAY TO 60-90% ON MONDAY, WITH HIGHER CHANCES TO THE SOUTH.
SEAS WILL REMAIN FAIRLY STEADY AT 4-7 FT WITH A PERSISTENT
WESTERLY TO NORTHWESTERLY SWELL THROUGH THIS WEEKEND. -36/23
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...NONE.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page