297
FXUS66 KPQR 041735 AAA
AFDPQR
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE PORTLAND OR
1034 AM PDT SAT JUL 4 2026
UPDATED AVIATION DISCUSSION.
SYNOPSIS
EXPECT A WARM AND DRY 4TH OF JULY WEEKEND ACROSS
NORTHWEST OREGON AND SOUTHWEST WASHINGTON. TEMPERATURES WARM UP
SLIGHTLY SUNDAY AND MONDAY AS HIGH PRESSURE BUILDS, LEADING TO
LOCALIZED MODERATE HEATRISK. AN UPPER-LEVEL TROUGH MOVING INTO
BRITISH COLUMBIA TUESDAY TO WEDNESDAY WILL COOL TEMPERATURES A
FEW DEGREES AND BRING CHANCES FOR PRECIPITATION ALONG THE SOUTH
WASHINGTON AND NORTH OREGON COAST. DRY AND WARMER CONDITIONS
RETURN ON THURSDAY, HOWEVER PERSISTENT ONSHORE FLOW WILL HELP
TO MAINTAIN NEAR NORMAL DAYTIME HIGHS ACROSS NORTHWEST OREGON
AND SOUTHWEST WASHINGTON. MAKE SURE TO PRACTICE WATER SAFETY
WHEN SWIMMING IN LOCAL RIVERS.
SHORT TERM...TODAY THROUGH MONDAY NIGHT
MINIMAL CHANGE IN THE
OVERALL SYNOPTIC PATTERN AS ZONAL FLOW ALOFT CONTINUES TO BE
MAINTAINED ACROSS THE PACIFIC NORTHWEST AS AN UPPER-LEVEL
TROUGH SWINGS THROUGH BRITISH COLUMBIA AND UPPER-LEVEL RIDGING
CONTINUES TO BUILD OVER THE GREAT BASIN. THIS SET UP WILL HELP
MAINTAIN ONSHORE FLOW WITH TEMPERATURES NEAR TO SLIGHTLY ABOVE
NORMAL ACROSS THE CWA TODAY. EXPECT AFTERNOON HIGHS IN THE
UPPER 70S TO MID 80S ACROSS INTERIOR VALLEYS AND LOW TO UPPER
60S ALONG THE COAST.
SUNDAY TO MONDAY, ENSEMBLE GUIDANCE CONTINUES TO SHOW THE GREAT
BASIN HIGH PRESSURE, BUILDING INTO THE REGION. THIS WILL RESULT
IN WARMER TEMPERATURES ACROSS THE CWA. EXPECT DAYTIME HIGHS IN
FOR THE INTERIOR VALLEYS IN THE MID TO UPPER 80S AND INTO THE
MID 60S TO MID 70S ALONG THE COAST. MODEL ENSEMBLE GUIDANCE
CONTINUES TO MAINTAIN THAT MONDAY WILL BE THE WARMEST DAY. THE
LATEST NBM GUIDANCE HAS A 10-35% CHANCE FOR MONDAY AFTERNOON
HIGHS EXCEEDING 90 DEGREES ALONG THE I-5 CORRIDOR FROM EUGENE,
OR TO THE PORTLAND/VANCOUVER METRO AREA, COLUMBIA RIVER GORGE,
AND UPPER HOOD RIVER VALLEY. THIS WILL RESULT IN LOCALIZED
MODERATE HEATRISK ON MONDAY, MEANING THIS LEVEL OF HEAT WILL
AFFECT THOSE SENSITIVE TO HEAT, ESPECIALLY THOSE WITHOUT
ADEQUATE COOLING OR HYDRATION. LOW TEMPERATURES IN THE 50S
ACROSS THE ENTIRE AREA SHOULD PROVIDE DECENT OVERNIGHT RELIEF
FROM THE HEAT.
IT IS IMPORTANT TO REMEMBER THAT WHILE TEMPERATURES WILL BE
WARMING UP FOR THE HOLIDAY WEEKEND AND NEXT WEEK, MANY LOCAL
LAKES AND RIVERS REMAIN VERY COLD AND CAN CAUSE COLD WATER
SHOCK. ALSO, RIVERS MAY STILL HAVE SWIFT CURRENTS IN SOME AREAS,
WHICH CAN QUICKLY SWEEP YOU AWAY. PLEASE PRACTICE WATER SAFETY
BY WEARING LIFE JACKETS, VISITING WITH A BUDDY, AND ALWAYS BEING
AWARE OF YOUR SURROUNDINGS. /42-10
LONG TERM...TUESDAY THROUGH FRIDAY
LOOKING INTO THE MIDDLE OF
NEXT WEEK AND TOWARDS NEXT WEEKEND, THE MAJORITY OF ENSEMBLE
MEMBERS ARE SHOWING AN UPPER-LEVEL TROUGH FROM THE GULF OF
ALASKA MOVING DOWN INTO BRITISH COLUMBIA THUS COMPRESSING THE
GREAT BASIN UPPER LEVEL HIGH. GIVEN THE MORE NORTHERN TRACK OF
THIS TROUGH, MOST PLACES ACROSS THE AREA IS EXPECTED TO BE DRY.
AN EXCEPTION WOULD BE THE SOUTH WASHINGTON AND NORTH OREGON
COAST WHERE THIS SYSTEM FAVORS A 15-30% CHANCE FOR LIGHT RAIN
FROM TUESDAY NIGHT TO WEDNESDAY, BUT IT SHOULD BE NOTED THAT
CURRENT QPF TOTALS ARE MINIMAL AT BEST. DESPITE THE LACK OF
WIDESPREAD, IF ANY PRECIPITATION, ONSHORE FLOW WILL INCREASE
AND SUPPORT TEMPERATURES COOLING A FEW DEGREES CLOSER TO
SEASONAL NORMALS FOR EARLY JULY. WEST-NORTHWESTERLY WINDS ARE
GENERALLY EXPECTED TO BE LIGHT FOR MOST AREAS DURING THIS TIME.
HOWEVER, WILL SEE LOCALLY BREEZIER ALONG THE CENTRAL COLUMBIA
RIVER GORGE AND UPPER HOOD RIVER VALLEY, WHERE THERE IS A 25-40%
CHANCE FOR AT LEAST ISOLATED WIND GUSTS EXCEEDING 40 MPH
TUESDAY AND WEDNESDAY. AS FOR THE END OF NEXT WEEK, MOST
ENSEMBLE MEMBERS SHOW THE BRITISH COLUMBIA TROUGH WEAKENING AS
IT MOVES EASTWARD. AT THE SAME TIME, THE GREAT BASIN HIGH LOOKS
TO RE-ESTABLISH ITSELF. THIS WILL BRING ABOUT A RETURN OF ZONAL
FLOW FOR THE PAC NW WHICH WILL BRING WARM AND DRY CONDITIONS
BACK INTO THE FORECAST. /42-10
AVIATION
HIGH PRESSURE LINGERS OVER THE AREA INCREASING DAYTIME
HEATING, AND FORMING OVERNIGHT INVERSIONS. GENERALLY NORTHWESTERLY
FLOW THROUGH THE FORECAST THEREFORE HAVE SEEN MORE PERVASIVE MVFR
CIGS THAN PREVIOUS DAYS. BECAUSE OF THIS DENSE CLOUD DECK, WHICH
VIA PIREPS IS REPORTED AROUND 1700-3500 FT, IT MAY BE A BIT MORE
CHALLENGING TO FULLY DISSIPATE. HOWEVER, THE OVERALL TREND BASED
ON A MORE PERSISTENCE FORECAST SHOWS THESE CIGS IMPROVING AROUND
20Z SAT. AFTERNOON DIURNALLY DRIVEN NORTHERLY WINDS EXPECTED TODAY
WITH GUSTS UP TO 20 KT ALONG THE COAST, AND SUSTAINED 10-14 KT
WITHIN THE WILLAMETTE VALLEY - ESPECIALLY NEAR KEUG.
OVERNIGHT IS WHERE THE CHALLENGE COMES IN AND WHETHER OR NOT WE
WILL SEE MVFR CIGS REDEVELOP. SOME POSITIVES IS THAT THERE IS A
WEAK SHORTWAVE MOVING IN WHICH WILL INCREASE WINDS EARLIER AND
THUS MIXING ALOFT. HOWEVER, SOME MODELS CONTINUE TO SHOW AREAS OF
MVFR CIGS IN THE INTERIOR VALLEYS, WITH HIGH PROBABILITIES ALONG
THE COAST.
KPDX AND APPROACHES...MVFR CIGS THROUGH THE NEXT SEVERAL HOURS BUT
COULD LAST AS LATE AS 22Z SAT. NORTHERLY WINDS INCREASE OVER THE
AFTERNOON AFTER 20Z SAT, BUT WILL BE STRONGEST AFTER 00Z SUN.
AROUND A 70% CHANCE OF MVFR CIGS REDEVELOPING AFTER 14Z SUN WITH
SOME MODELS SUGGESTING SIMILAR PROBABILITY FOR IFR CIGS. HOWEVER,
DUE TO WINDS REMAINING ELEVATED AND DRIER AIR REMAINING, GETTING
THESE LEVELS WILL BE MORE DIFFICULT. CANNOT RULE IT OUT COMPLETELY
THOUGH. WINDS WILL BEGIN TO INCREASE LATE IN THE FORECAST AS A
WEAK DISTURBANCE PASSES THROUGH. -27
MARINE
HIGH PRESSURE OVER THE REGION RESULT IN INCREASING WINDS
AND BUILDING SEAS THROUGH MONDAY. NORTHERLY WINDS WILL SLOWLY
INCREASE THROUGH THIS AFTERNOON AND WILL RESULT IN GUSTS UP TO 20
KT BY THIS EVENING. WINDS WILL CONTINUE TO STRENGTHEN WITH GUSTS
UP TO 30 KT BY SUNDAY. SEAS WILL ALSO BUILD FROM 4 TO 6 FT TOWARDS
6 TO 8 FT BY SUNDAY. AS A RESULT, HAVE MAINTAINED THE CURRENT
SUITE OF SMALL CRAFT ADVISORIES THROUGH AT LEAST SUNDAY NIGHT.
HIGH PRESSURE WILL SLOWLY BECOME DISPLACED TOWARDS THE START OF
NEXT WEEK, THUS EASING OVERALL CONDITIONS BY MONDAY NIGHT/TUESDAY
WHICH IS EXPECTED TO PERSIST THROUGH THE REMAINDER OF NEXT WEEK.
-42
PQR WATCHES/WARNINGS/ADVISORIES
OR...NONE.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 PM PDT SUNDAY
FOR PZZ251-271.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 11 PM PDT SUNDAY
FOR PZZ252-272.
SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 11 PM PDT
SUNDAY FOR PZZ253-273.
WWW.WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSPORTLAND
X.COM/NWSPORTLAND
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