872
FXUS66 KPQR 060413 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PORTLAND OR
913 PM PDT TUE MAY 5 2026
UPDATED AVIATION DISCUSSION.
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
SATELLITE IMAGERY AT 04Z WED SHOWS MARINE STRATUS
SOCKED IN ALONG THE COAST AND FILLING BACK IN INLAND. THERE'S A 60-
80% CHANCE THAT MVFR CIGS ALONG THE COAST WILL LOWER TO IFR AFTER 07-
10Z WED. STRATUS IS EXPECTED TO CONTINUE FILLING IN OVER INLAND
AREAS OVER THE NEXT FEW HOURS WITH MVFR CONDITIONS DEVELOPING
BETWEEN 06-09Z WED. EXPECT STRATUS TO LINGER INTO MUCH OF WEDNESDAY
FOR INLAND AREAS, NOT IMPROVING TO VFR UNTIL AFTER 18-21Z. ALONG THE
COAST, IFR CONDITIONS WILL BECOME MVFR BY 16-18Z WED, BUT THERE'S A
LOW CHANCE (AROUND 20%) OF CONDITIONS IMPROVING TO VFR THROUGH THE
06Z TAF PERIOD. WINDS ARE EXPECTED TO REMAIN LIGHT AND VARIABLE
AROUND 5 KT OR LESS THROUGH WEDNESDAY MORNING, BECOMING WESTERLY TO
NORTHWESTERLY UP TO 8-10 KTS WITH A SEA BREEZE AFTER 21Z WED.
KPDX AND APPROACHES...VFR CONDITIONS ARE EXPECTED TO FALL TO MVFR
DUE TO MARINE STRATUS SOMETIME BETWEEN 06-09Z WED. CONDITIONS NOT
EXPECTED TO IMPROVE TO VFR AGAIN UNTIL 19-21Z WED. WINDS WILL BE
LIGHT AND VARIABLE THROUGH WEDNESDAY MORNING, BECOMING NORTHWEST UP
TO 8-10 KTS AFTER 21Z WED. -03
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. WINDS LATE TUESDAY
AFTERNOON HAVE BECOME WESTERLY AROUND 5 KT. 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