243
FXUS66 KPQR 042101
AFDPQR
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
201 PM PDT SAT JUL 4 2026
SYNOPSIS
EXPECT WARM AND SUNNY CONDITIONS FOR THE 4TH OF
JULY HOLIDAY. TEMPERATURES WARM UP SLIGHTLY TOMORROW 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 SLIGHT CHANCES FOR PRECIPITATION ALONG THE SOUTH
WASHINGTON COAST. SEASONABLE TEMPERATURES RETURN THURSDAY TO
FRIDAY WITH PERSISTENT ONSHORE FLOW. MAKE SURE TO PRACTICE WATER
SAFETY WHEN SWIMMING IN LOCAL RIVERS.
SHORT TERM...TODAY THROUGH MONDAY
SATELLITE IMAGERY AND
SURFACE OBSERVATIONS AS OF EARLY SATURDAY AFTERNOON SHOW SUNNY
SKIES FOR MOST AREAS ACROSS NORTHWEST OREGON AND SOUTHWEST
WASHINGTON AS MORNING STRATUS HAS DISSIPATED FROM DAYTIME
HEATING. THERE IS STILL SOME LINGERING STRATUS ALONG THE COAST,
BUT THAT SHOULD GRADUALLY DISSIPATE THIS AFTERNOON AND BRING
MOSTLY SUNNY SKIES TO THE COAST. EXPECT SEASONABLE TEMPERATURES
FOR THE 4TH OF JULY HOLIDAY WITH AFTERNOON HIGHS PEAKING IN
THE UPPER 70S TO LOW 80S ACROSS INTERIOR VALLEYS AND 60S ALONG
THE COAST. WE STILL HAVE ONSHORE FLOW, SO CAN'T RULE OUT SOME
MARINE CLOUDS OFF THE COAST THIS AFTERNOON AND EVENING. BY
TONIGHT, HIGH RESOLUTION GUIDANCE SUGGESTS ANOTHER RETURN OF
WIDESPREAD MARINE STRATUS ALONG THE COAST.
SUNDAY TO MONDAY, ENSEMBLE GUIDANCE CONTINUES TO SUGGEST HIGH
PRESSURE BUILDING OVER THE PACIFIC NORTHWEST, RESULTING IN
WARMER TEMPERATURES ACROSS THE AREA. HIGH TEMPERATURES ACROSS
INTERIOR VALLEYS ARE FORECAST A FEW DEGREES WARMER TOMORROW IN
THE MID 80S, THEN PEAKING ON MONDAY IN THE UPPER 80S. CHANCES
FOR EXCEEDING 90 DEGREES HAVE DECREASED SINCE YESTERDAY - NOW
ONLY A 10-35% CHANCE ACROSS THE WILLAMETTE VALLEY, 40-50% CHANCE
ACROSS THE UPPER HOOD RIVER VALLEY, AND LESS THAN 10% FOR THE
REST OF THE INTERIOR VALLEYS. HOWEVER, WE'LL STILL HAVE SOME
LOCALIZED MODERATE HEATRISK ON MONDAY WITHIN THE INNER PORTLAND
METRO AND PARTS OF THE GORGE AND UPPER HOOD RIVER VALLEY. THIS
MEANS 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
WARM THIS 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. -10
LONG TERM...TUESDAY THROUGH FRIDAY
THE MAJORITY OF ENSEMBLE
MEMBERS CONTINUE TO SHOW AN UPPER-LEVEL TROUGH FROM THE GULF OF
ALASKA MOVING DOWN INTO BRITISH COLUMBIA AND AN UPPER-LEVEL HIGH
IN THE SOUTHWEST UNITED STATES, RESULTING IN ZONAL FLOW OVER THE
PACIFIC NORTHWEST. GIVEN THE MORE NORTHERN TRACK OF THE INCOMING
TROUGH, THE MAJORITY OF OUR AREA IS EXPECTED TO BE DRY. AN
EXCEPTION WOULD BE THE SOUTH WASHINGTON COAST WHERE THIS SYSTEM
FAVORS A SLIGHT CHANCE (15-25%) FOR LIGHT RAIN ON WEDNESDAY.
GIVEN HOW DRY OUR AIR MASS IS AND HOW WEAK THIS SYSTEM WOULD BE
AS IT PASSES THROUGH OUR AREA, FORECAST PRECIPITATION AMOUNTS
ARE MINIMAL (AROUND 0.01" OR LESS). DESPITE THE LACK OF
PRECIPITATION, ONSHORE FLOW WILL INCREASE MID-WEEK 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 WINDS ALONG THE CENTRAL COLUMBIA RIVER GORGE
AND UPPER HOOD RIVER VALLEY, WHERE THERE IS A 25-45% CHANCE FOR
AT LEAST ISOLATED WIND GUSTS EXCEEDING 40 MPH TUESDAY AND
WEDNESDAY.
AT THE END OF NEXT WEEK, MOST ENSEMBLE MEMBERS SHOW THE
AFOREMENTIONED TROUGH WEAKENING AS IT MOVES EASTWARD THROUGH
BRITISH COLUMBIA. AT THE SAME TIME, ENSEMBLE MEMBERS ARE SHOWING
ADDITIONAL TROUGHING MOVING DOWN FROM THE GULF OF ALASKA INTO
THE NORTHEAST PACIFIC/BRITISH COLUMBIA. THERE STILL REMAINS
UNCERTAINTY WITH THE EXACT PLACEMENT AND MAGNITUDE OF THIS
ADDITIONAL TROUGHING, THUS UNCERTAINTY WITH ANY POTENTIAL
IMPACTS AT THIS TIME. IF THIS PATTERN DOES PAN OUT, THIS WOULD
SUPPORT CONTINUED ONSHORE FLOW WITH SEASONABLE TEMPERATURES.
-10/42
AVIATION
HIGH PRESSURE REMAINS OVER THE REGION KEEPING
CONDITIONS WARM AND DRY. MARINE STRATUS HAS FINALLY BROKEN OUT
AND THE COAST IS BEGINNING TO LIFT. WILL CONTINUE TO SEE
IMPROVEMENT THROUGH THE AFTERNOON BEFORE CLOUDS FILL IN ONCE
AGAIN OVERNIGHT. 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...VFR THROUGH THE NEXT 12 HOURS OR SO THEN
MARINE STRATUS APPEARS TO MOVE BACK IN AFTER 10Z SUN. 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. 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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