495
FXUS66 KSEW 041011
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
311 AM PDT SAT JUL 4 2026
SYNOPSIS
WEAK UPPER LEVEL TROUGH OVER THE AREA TODAY AND TONIGHT WILL
MOVE EAST SUNDAY. WEAK UPPER LEVEL RIDGE SUNDAY AND MONDAY WILL
MOVE EAST TUESDAY. ANOTHER UPPER LEVEL TROUGH WILL MOVE
OVER WESTERN WASHINGTON WEDNESDAY AND REMAIN THROUGH THE END OF
THE WEEK.
SHORT TERM /TODAY THROUGH MONDAY/
SATELLITE IMAGERY SHOWS CLOUDS FILLING IN PRETTY FAST OVER
WESTERN WASHINGTON EARLY THIS MORNING. THE AURORA WAS VISIBLE ON
SOME WEB CAMS NORTH OF SEATTLE BEFORE THE CLOUDS ARRIVED.
TEMPERATURES AT 3 AM/10Z WERE IN THE 50S AND LOWER 60S.
WEAK UPPER LEVEL TROUGH OVER WESTERN WASHINGTON TODAY WITH LIGHT
ONSHORE FLOW IN THE LOWER LEVELS. PRETTY MUCH A REPLAY OF FRIDAY
WITH MORNING CLOUDS GIVING WAY TO SOME SUNSHINE IN THE
AFTERNOON. HIGHS IN THE UPPER 60S TO MID 70S OVER THE INTERIOR
AND MID 60S ALONG THE COAST.
UPPER LEVEL TROUGH HANGING OVER THE AREA TONIGHT BEFORE MOVING
EAST SUNDAY. LOW LEVEL FLOW TURNING LIGHT OVERNIGHT WITH
NORTHERLY FLOW IN THE LOWER LEVELS SUNDAY. THIS WILL THIN OUT
THE MARINE LAYER LEADING TO AN EARLIER BREAKOUT ON SUNDAY.
BREEZY NORTH WIND IN THE AFTERNOON ESPECIALLY NEAR THE WATER.
WITH A LITTLE MORE SUNSHINE HIGHS A TOUCH WARMER, IN THE 70S
OVER THE INTERIOR AND UPPER 60S ALONG THE COAST.
TEMPORARY UPPER LEVEL RIDGE BUILDING SUNDAY NIGHT AND MONDAY.
%00 MB HEIGHTS RISING INTO THE UPPER 570 DMS TO LOWER 580 DMS.
LIGHT FLOW IN THE LOWER LEVELS. MONDAY WILL BE THE WARMEST DAY
IN THE NEXT SEVEN DAYS FOR THE INTERIOR WITH HIGHS IN THE MID
70S TO MID 80S. HIGHS ON THE COAST WITH AN AFTERNOON SEABREEZE
STAYING IN THE MID TO UPPER 60S. FELTON
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/
UPPER LEVEL RIDGE MOVES EAST MONDAY NIGHT WITH AN UPPER LEVEL
TROUGH AND ASSOCIATED FRONT APPROACHING THE COAST TUESDAY.
INCREASING ONSHORE FLOW DURING THE DAY TUESDAY WILL DROP HIGHS
IN THE INTERIOR BACK INTO THE 70S. HIGHS ON THE COAST IN THE
LOWER TO MID 60S.
UPPER LEVEL TROUGH AND ASSOCIATED FRONT MOVING THROUGH WEDNESDAY
FOR MOSTLY CLOUDY SKIES AND A CHANCE OF RAIN FOR MOST OF THE
AREA. HIGHS CONTINUE TO COOL WITH 60S AND LOWER 70S IN THE
FORECAST.
WEAK UPPER LEVEL TROUGH HANGING AROUND WEDNESDAY NIGHT THROUGH
THE END OF THE WEEK. LOW LEVEL ONSHORE FLOW MAKING FOR A MORNING
CLOUDS AFTERNOON SUNSHINE SCENARIO THURSDAY AND FRIDAY. HIGHS
REMAINING NEAR OR A COUPLE OF DEGREES BELOW NORMAL, IN THE UPPER
60S TO MID 70S OVER THE INTERIOR AND MID 60S ON THE COAST.
AVIATION
MVFR CIGS SLOWLY FILLING IN THIS MORNING, EXPECTING WIDESPREAD MVFR
CIGS IN WITHIN THE NEXT HOUR OR SO. IMPROVEMENT TO VFR EXPECTED
AFTER 17-19Z. THE COAST MAY SEE SOME BRIEF IMPROVEMENT THIS
AFTERNOON TO LOW-END VFR. HOWEVER, IT IS POSSIBLE THAT CEILINGS MAY
HOVER AROUND HIGH-END MVFR. ANOTHER ROUND OF WIDESPREAD LOW CLOUDS
EXPECTED TONIGHT/EARLY SUNDAY MORNING, WITH LATEST PROBABILITIES
AROUND 30-50% FOR INTERIOR TERMINALS AND 60-90% FOR THE COAST FOR
MVFR CIGS. SOUTHWESTERLY WINDS IN THE INTERIOR TERMINALS AND
NORTHWESTERLY WINDS ALONG THE COAST AND STRAIT OF JUAN DE FUCA THIS
MORNING. STRONG ONSHORE FLOW THIS EVENING ALONG THE STRAIT OF JUAN
DE FUCA WITH GUSTS TO 20 KT POSSIBLE THROUGH SUNDAY MORNING. THIS
WILL RESULT IN NORTHWESTERLY WINDS SPILLING INTO PUGET SOUND
TERMINALS THIS AFTERNOON, THEN SHIFTING NORTHEASTERLY IN THE EVENING
WITH GUSTS TO 15 KT POSSIBLE.
KSEA...MVFR CONDITIONS EARLY THIS MORNING. CEILINGS EXPECTED TO
IMPROVE THIS AFTERNOON AFTER 18Z. MVFR CIGS LOOK TO RETURN (40%
CHANCE) EARLY SUNDAY MORNING AFTER 11Z. SOUTHWESTERLY WINDS THIS
MORNING 5-7 KT WILL SHIFT NORTHWESTERLY THIS AFTERNOON AFTER 21Z TO
7-9 KT. NORTHEASTERLY WINDS 8-12 KT AFTER 02Z WITH GUSTS TO 15 KT
THROUGH SUNDAY MORNING.
29
MARINE
A RATHER STAGNANT WEATHER PATTERN WILL PERSIST OVER WASHINGTON'S
WATERS INTO NEXT WEEK. BROAD HIGH PRESSURE OVER THE NORTHEAST
PACIFIC AND LOWER PRESSURE INLAND WILL KEEP AN ONSHORE FLOW PATTERN.
THIS WILL RESULT IN INCREASED WESTERLIES THROUGH THE STRAIT OF JUAN
DE FUCA EACH EVENING, SOME HAVING THE POTENTIAL TO REACH SMALL CRAFT
THRESHOLDS. THERE IS HIGH CONFIDENCE (GREATER THAN 70%) FOR STRONG
WESTERLIES THIS EVENING THROUGH THE STRAIT. GUIDANCE ALSO SUGGESTS
THERE IS A 70% CHANCE OR HIGHER FOR SMALL CRAFT WINDS TO REACH
ADMIRALTY INLET THIS EVENING AS WELL. THEREFORE, SMALL CRAFT
ADVISORIES ARE SET TO GO INTO EFFECT THE CENTRAL/EAST STRAIT AND
ADMIRALTY INLET LATER THIS EVENING. WINDS WILL ALSO INCREASE FOR THE
LOWER COASTAL WATERS LATE THIS EVENING TO ADVISORY THRESHOLDS. THERE
IS HIGH CONFIDENCE (75-85%) FOR INCREASED NORTHWESTERLY WINDS SUNDAY
EVENING ACROSS ALL PORTIONS OF THE COASTAL WATERS, LIKELY REQUIRING
ADDITIONAL ADVISORIES. LONG TERM GUIDANCE HIGHLIGHTS A 60-90% CHANCE
FOR SMALL CRAFT WINDS THROUGH THE STRAIT NEXT WEEK, LIKELY REQUIRING
ADDITIONAL HEADLINES. A FEW WEAK FRONTS WILL MOVE THROUGH THE WATERS
THROUGHOUT THE WEEK, BUT HIGH PRESSURE IS EXPECTED TO REBUILD
QUICKLY OVER THE WATERS BEHIND THE FRONTS.
SEAS WILL BUILD LATE THIS EVENING TO 6-8 FT AND UP TO 10 FT THROUGH
MONDAY. SEAS WILL GRADUALLY SUBSIDE BELOW 10 FT ON TUESDAY TO 4-6
FT.
29
FIRE WEATHER
EVEN WITH THE SLIGHT WARMING TREND INTO NEXT MONDAY THE LOW
LEVEL FLOW NEVER TURNS OFFSHORE. THIS WILL KEEP GOOD OVERNIGHT
RELATIVE HUMIDITY RECOVERIES IN THE FORECAST AND HELP SUBDUE
FIRE WEATHER CONCERNS DESPITE THE WARMER TEMPERATURES. ANOTHER
FRONT IN THE MIDDLE OF NEXT WEEK WILL BRING A CHANCE OF RAIN TO
THE AREA KEEPING FIRE WEATHER CONCERNS AT A MINIMUM.
WE ALREADY HAVE SMALL FIRES CROPPING UP IN THE OLYMPICS AND
CASCADES EVEN WITHOUT ELEVATED FIRE WEATHER CONDITIONS. IF YOU
ARE IN THE MOUNTAINS THE NEXT FEW DAYS PLEASE BE EXTRA CAREFUL.
FELTON
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 5 AM PDT EARLY THIS MORNING FOR
CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA-EAST ENTRANCE
U.S. WATERS STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 3 AM PDT
SUNDAY FOR CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA-
EAST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 3 AM PDT
SUNDAY FOR ADMIRALTY INLET.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 9 AM PDT SUNDAY
FOR COASTAL WATERS FROM POINT GRENVILLE TO CAPE
SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT
GRENVILLE TO CAPE SHOALWATER OUT 10 NM.
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