983
FXUS66 KSEW 081046
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
346 AM PDT SUN JUN 8 2025
SYNOPSIS
UPPER LEVEL RIDGE OVER WESTERN WASHINGTON TODAY WILL
WEAKEN SLIGHTLY MONDAY BEFORE MOVING OFF TO THE EAST TUESDAY.
POSSIBLE RECORD HIGHS IN A FEW LOCATIONS TODAY. WEAK UPPER LEVEL
TROUGH PASSING THROUGH WEDNESDAY. STRONGER UPPER LEVEL TROUGH
ARRIVING THURSDAY WITH ANOTHER UPPER LEVEL TROUGH REMAINING OVER
THE COASTAL WATERS FRIDAY AND SATURDAY.
SHORT TERM /TODAY THROUGH TUESDAY/
SATELLITE IMAGERY SHOWS
CLEAR SKIES OVER WESTERN WASHINGTON EARLY THIS MORNING.
TEMPERATURES AT 3 AM/10Z WERE IN THE MID 50S TO MID 60S.
UPPER LEVEL RIDGE OVER WESTERN WASHINGTON TODAY WITH LIGHT
SURFACE GRADIENTS. CROSS CASCADE GRADIENT STILL POSITIVE THIS
MORNING AND NEVER TURNS NEGATIVE TODAY. WINDS IN THE LOWER LEVELS
AT 925 MB AND 850 MB LIGHT EASTERLY THIS MORNING BUT MODELS HAVE
THESE WINDS SWITCHING TO LIGHT NORTHWESTERLY THIS AFTERNOON. 850
MB TEMPERATURES WARMING TO PLUS 18-20C BY 00Z MONDAY ( IN THIS
TYPE OF SITUATION FOR A QUICK FIRST ATTEMPT AT THE SEATTLE HIGH
JUST TAKE THE 850 MB TEMPERATURES, IN THIS CASE PLUS 19-20C OR
66-68F, AND ADD 20 DEGREES F. IF WE HAD SOME OFFSHORE FLOW ADD 25
DEGREES F ) WHICH PUTS HIGHS IN THE 80S AND LOWER 90S FOR THE
INTERIOR. WITH THE LOW LEVEL FLOW NOT GOING OFFSHORE, AFTERNOON
SEABREEZES WILL KEEP HIGHS IN THE 70S NEAR THE STRAIT AND ALONG
THE OCEAN. RECORDS ARE POSSIBLE BOTH IN SEATTLE, CURRENT RECORD 87
IN 2015, AND HOQUIAM, CURRENT RECORD 75 IN 1972. OTHER LOCATIONS
CLOSE TO RECORDS BELLINGHAM, FORECAST HIGH 80 RECORD 82 IN 1955
AND OLYMPIA FORECAST HIGH 91 RECORD 94 IN 1948.
UPPER LEVEL RIDGE REMAINING OVER THE AREA TONIGHT WITH LIGHT FLOW
IN THE LOWER LEVELS. THE LACK OF OFFSHORE FLOW WILL ALLOW LOWS TO
DROP INTO THE 50S AND LOWER 60S.
UPPER LEVEL RIDGE WEAKENING SLIGHT MONDAY BUT REMAINING OVER
WESTERN WASHINGTON. SURFACE GRADIENTS TURNING ONSHORE IN THE LATE
MORNING AND AFTERNOON. TEMPERATURES ALOFT COOLING SLIGHTLY WITH
MODEL 850 MB TEMPERATURES A DEGREE OR TWO COOLER THAN TODAY. ALL
THIS LEADS TO A SLIGHTLY COOLER DAY MONDAY, LESS THAN 5 DEGREES OF
COOLING, FOR THE INTERIOR. HIGHS IN THE MID 70S TO MID 80S.
INCREASING ONSHORE FLOW IN THE AFTERNOON WILL COOL THE COAST DOWN
MORE THAN THE INTERIOR WITH HIGHS IN THE MID TO UPPER 60S.
UPPER LEVEL RIDGE CONTINUING TO WEAKEN MONDAY NIGHT WITH THE RIDGE
SLIDING OFF TO THE EAST TUESDAY. LOW LEVEL ONSHORE FLOW DOESN'T
REALLY INCREASE MUCH EVEN WITH THE UPPER LEVEL RIDGE AXIS TO THE
EAST. TEMPERATURES ALOFT COOLING AGAIN WITH MODEL 850 MB
TEMPERATURES DOWN TO PLUS 14-16C BY 00Z WEDNESDAY. WEAK MARINE
PUSH MONDAY NIGHT INTO TUESDAY DROPPING TUESDAY HIGH TEMPERATURES
ANOTHER 5 TO 10 DEGREES OVER THE INTERIOR. HIGHS MOSTLY IN THE
70S. HIGHS ON THE COAST IN THE LOWER TO MID 60S. ONSHORE FLOW
MONDAY NIGHT GIVING THE AREA COOLER MORNING LOWS FOR TUESDAY
MORNING, IN THE LOWER TO MID 50S.
THE HEAT ADVISORY WILL GO INTO EFFECT THIS MORNING AT 10 AM AND
REMAIN IN EFFECT UNTIL 10 PM MONDAY FOR PORTIONS OF THE INTERIOR.
IF YOU ARE THINKING THIS IS AN UNUSUAL START TO JUNE YOU WOULD BE
RIGHT. IN 80 YEARS OF RECORDS AT SEATTLE-TACOMA AIRPORT THE FIRST
10 DAYS OF JUNE HAVE BEEN DRY IN ONLY 9 YEARS. THE LAST TIME IN
2014. IT IS EVEN RARER FOR THE FIRST TWO WEEKS OF JUNE TO BE DRY.
THAT HAS ONLY HAPPENED FOUR YEARS ( 2009, 1996, 1982 AND 1969 ).
HIGHS OF 85 DEGREES PLUS ARE A LITTLE UNCOMMON FOR SEATTLE THIS
TIME OF YEAR. IN THE 80 YEARS OF RECORDS IN THE FIRST 10 DAYS OF
JUNE IT HAS HAPPENED 29 TIMES. 90 DEGREE PLUS DAYS HAVE ONLY
OCCURRED 8 TIMES. THE FEDERAL BUILDING IN DOWNTOWN SEATTLE DID HIT
100 DEGREES ON JUNE 9TH 1955. THE HIGH AT THE OFFICIAL SEATTLE
LOCATION, SEATTLE-TACOMA AIRPORT, WAS 96 DEGREES THAT DAY.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
EXTENDED FORECAST MARKS
THE RETURN TO COOLER JUNE WEATHER BUT STILL NOT MUCH IN THE WAY
OF PRECIPITATION. VERY WEAK UPPER LEVEL TROUGH MOVING THROUGH
WEDNESDAY WITH JUST A LITTLE INCREASE IN ONSHORE FLOW CONTINUING
THE COOLING TREND. STRONGER UPPER LEVEL TROUGH MOVING THROUGH
THURSDAY PUSHING HIGH TEMPERATURES BACK TO BELOW NORMAL WITH AN
INCREASE IN CLOUD COVER. ANOTHER UPPER LEVEL TROUGH HANGS OFF THE
COAST FRIDAY AND SATURDAY WITH SOUTHWESTERLY FLOW ALOFT OVER THE
AREA. PLENTY OF CLOUD COVER BUT OTHER THAN A CHANCE OF SHOWERS
OVER THE NORTHERN AND CENTRAL CASCADES AND FOOTHILLS THE FORECAST
REMAINS DRY. HIGHS FOR THE INTERIOR IN THE MID 60S TO MID 70S
WEDNESDAY, IN THE 60S FOR THURSDAY THROUGH SATURDAY. HIGHS ON THE
COAST REMAINING IN THE LOWER 60S. FELTON
AVIATION
WIDESPREAD VFR CONDITIONS WITH CLEAR SKIES AS A HIGH
PRESSURE RIDGE REMAINS FIRMLY IN PLACE OVER THE REGION. STRATUS MAY
SLIDE INLAND ALONG THE IMMEDIATE COAST EARLY THIS MORNING, WITH
POTENTIAL LIFR CIGS AT HQM. OTHERWISE, VFR WITH MOSTLY CLEAR
CONDITIONS THROUGH THE PERIOD. LIGHT N/NW SURFACE WINDS WILL
INCREASE THIS AFTERNOON TO 5-10 KT.
KSEA...VFR CONDITIONS WITH MAINLY CLEAR SKIES DURING THE TAF PERIOD.
NE WINDS AT 4 TO 6 KTS WILL SHIFT MORE N/NW THIS AFTERNOON AND
INCREASE TO 7 TO 11 KT.
15
MARINE
HIGH PRESSURE WILL REMAIN OVER THE COASTAL WATERS THROUGH
WEDNESDAY. NORTHERLY DIURNAL DRIVEN WINDS EXPECTED FOR THE INTERIOR
WATERS THROUGH TUESDAY. NORTHWEST WINDS WILL ALSO REMAIN ELEVATED
OVER THE COASTAL WATERS THROUGH NEXT WEEK. ONSHORE FLOW WILL
INCREASE MIDWEEK.
INCREASING ONSHORE FLOW TUESDAY INTO WEDNESDAY WILL ALSO BRING
POTENTIAL SCA WINDS DURING THE EVENING PERIODS THROUGH THE STRAIT OF
JUAN DE FUCA. IN ADDITION, WILL NEED TO MONITOR THE POTENTIAL FOR
ANY GALES IN THE STRAIT OF JUAN DE FUCA MIDWEEK WITH THE INCREASED
WEST WINDS.
SEAS OF 4 TO 6 FEET THROUGH SUNDAY MORNING WILL BUILD TO 7 TO 11
FEET MONDAY INTO TUESDAY. IN ADDITION, PERIODS WILL ALSO RANGE 8 TO
12 SECONDS LATER SUNDAY INTO MONDAY.
JD
SEW WATCHES/WARNINGS/ADVISORIES
WA...HEAT ADVISORY FROM 10 AM THIS MORNING TO 10 PM PDT MONDAY FOR
CITY OF SEATTLE-DOWNTOWN EVERETT / MARYSVILLE AREA-EASTERN
KITSAP COUNTY-EASTSIDE-FOOTHILLS AND VALLEYS OF CENTRAL
KING COUNTY-FOOTHILLS AND VALLEYS OF PIERCE AND SOUTHERN
KING COUNTIES-FOOTHILLS AND VALLEYS OF SNOHOMISH AND
NORTHERN KING COUNTIES-FOOTHILLS AND VALLEYS OF THURSTON
AND LEWIS COUNTIES-FOOTHILLS AND VALLEYS OF THE NORTH
CASCADES-LOWLANDS OF LEWIS AND SOUTHERN THURSTON COUNTIES-
LOWLANDS OF PIERCE AND SOUTHERN KING COUNTIES-NORTHERN HOOD
CANAL-OLYMPIA AND SOUTHERN PUGET SOUND-SHORELINE / LYNNWOOD
/ SOUTH EVERETT AREA-SOUTHERN HOOD CANAL.
PZ...NONE.
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