968
FXUS66 KSEW 081002
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
302 AM PDT MON JUN 8 2026
SYNOPSIS
COOL AND UNSETTLED CONDITIONS WILL CONTINUE ACROSS
WESTERN WASHINGTON FOR THE FIRST HALF OF THE WEEK AS A PAIR OF
SYSTEMS MOVE THROUGH THE REGION. A PATTERN SHIFT TOWARD DRY AND
CONSIDERABLY WARMER CONDITIONS IS EXPECTED LATE IN WEEK AS
STRONG HIGH PRESSURE ALOFT BUILDS INTO THE REGION.
SHORT TERM /TODAY THROUGH WEDNESDAY/
LATEST IR SATELLITE IMAGERY SHOWS LEADING EDGE OF THE NEXT INCOMING
SYSTEM STILL OUT OVER THE COASTAL WATERS WITH JUST THE SLIGHTEST
HINTS AT ASSOCIATED PRECIP SHOWING UP ON CURRENT RADAR. THIS
REFLECTS THE CONSISTENT MODEL DATA SUGGESTING A VERY SLOW APPROACH,
MAKING IT TO THE COASTLINE BY LATE THIS MORNING AND BEGINNING ITS
INLAND INTRUSION THIS AFTERNOON. WIDESPREAD RAINFALL STILL ON TAP BY
THIS EVENING AND INTO THE OVERNIGHT HOURS WITH QPF VALUES SUGGESTING
PERIODS OF MODERATE RAINFALL RATES OVER THE SOUTHERN HALF OF THE
CWA, STRETCHING AS FAR NORTH AS EVERETT.
THE PARENT UPPER LOW WILL BE THE MAIN HEADLINE FOR TUESDAY AS RAINS
OVER W WA PERSIST. THE PLACEMENT AND TRACK OF THE MAIN LOW REMAINS A
POINT OF CONTENTION AMONGST MODEL DATA AND WHILE THIS WILL NOT
SPECIFICALLY IMPACT THE AMOUNT OF CHANCES OF PRECIP, IT DOES PLAY A
ROLE IN ANY POTENTIAL THUNDERSTORM DEVELOPMENT. LEVELS OF CAPE
AVAILABLE HAS SEEN SOME VARIATION, BUT LIS REMAIN ON THE POSITIVE
SIDE OF THINGS WHICH WOULD NOT BE HELPFUL TO ANY DEVELOPMENT.
PERSISTENT CLOUDY CONDITIONS AND COOLER DAYTIME TEMPS WILL CERTAINLY
BE ANOTHER FACTOR TO OVERCOME CONVECTION-WISE. THIS LEAVES A LOT OF
THE WORK TO BE DONE BY THE UPPER LOW AND THE UNCERTAINTY REGARDING
ITS PATH DOES NOT FOSTER CONFIDENCE IN POTENTIAL THUNDERSTORM
DEVELOPMENT. NBM REMAINS CONSISTENT IN ITS ADVERTISING AND GIVEN
ASSOCIATED MESSAGING, FELT PRUDENT TO LEAVE THE PROSPECT IN THE
FORECAST AT THIS TIME...ALTHOUGH GIVEN THE FACTORS LISTED ABOVE, AN
EMPHASIS ON ISOLATED DEVELOPMENT IS CERTAINLY WARRANTED.
WEDNESDAY WILL SEE THE UPPER LEVEL TROUGH PULL AWAY FROM W WA AND
THUS WILL SEE PRECIP CHANCES WHITTLE AWAY THROUGH THE DAY. LATEST
DATA SUGGESTS THIS TO BE A BIT FASTER THAN PREVIOUSLY ADVERTISED,
WITH THE MAJORITY OF THE CWA DRY BY AFTERNOON /WITH ONLY SOME LOW
END POPS TO CONTEND WITH/.
DAYTIME HIGHS FOR THE NEAR TERM DO NOT SEE MUCH IN THE WAY OF
VARIATION WITH UPPER 50S TO LOWER 60S EXPECTED TODAY AND TUESDAY. AS
THE SYSTEM EXITS THE AREA WEDNESDAY, THAT SHOULD ALLOW SOME BREAKS
IN THE CLOUDS, LETTING PEEKS OF SUNSHINE TO NUDGE TEMPS UPWARD, BUT
NOT BY TOO MUCH...RANGING IN THE LOWER TO MID 60S.
18
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
DRY CONDITIONS AREAWIDE BY WEDNESDAY NIGHT AS THE INFLUENCE FROM AN
UPPER LEVEL RIDGE BUILDING OVER THE EASTERN PACIFIC BEGINS TO NUDGE
ITS WAY INTO W WA. WITH THIS FEATURE BEING VERY SLOW TO MOVE
EASTWARD THROUGHOUT THE REMAINDER OF THE FORECAST PERIOD, THE SONG
WILL REMAIN THE SAME FOR THE LATTER HALF OF THE WEEK AS CONDITIONS
WILL REMAIN DRY AND TEMPERATURES BEGIN A STEEP WARMING TREND.
DAYTIME HIGHS THURSDAY JUMP UP INTO THE UPPER 60S TO LOWER 70S.
FRIDAY SEES FURTHER UPWARD MOTION INTO THE MID TO UPPER 70S.
SATURDAY GETS MANY INTERIOR LOCATIONS INTO THE UPPER 70S TO MID 80S.
SUNDAY FINALLY SEES SOME LOCATIONS BREAK 90 AS TEMPS RANGE FROM THE
MID 80S TO LOWER 90S.
TEMPS OF THIS CALIBER WILL INDUCE THERMAL TROUGHING OVER THE AREA,
ALLOWING FOR OFFSHORE FLOW TO DEVELOP SATURDAY NIGHT INTO SUNDAY.
THIS EASTERLY FLOW IMPORTING MORE HOT AND DRY AIR INTO THE AREA. AS
THIS HEAT PERSISTS, HEATRISK BECOMES AN INCREASING CONCERN. THE
START OF THIS WARMING TREND, THURSDAY AND FRIDAY, CONTINUE TO LOOK
TO BE MINOR IN THESE TERMS. MODERATE HEATRISK AREAS BEGIN TO POP UP,
MAINLY IN THE SW INTERIOR, SATURDAY WHILE WIDESPREAD MODERATE
CONDITIONS EXPECTED FOR SUNDAY. WHILE HAVING ANY MAJOR HEATRISK
EMERGING BEYOND THE FORECAST PERIOD SEEMS TO HAVE LOWER
PROBABILITIES AT THIS TIME, PERSISTING MODERATE CONDITIONS APPEAR TO
BE MORE FAVORABLE.
18
AVIATION
SOUTHWESTERLY FLOW WILL PERSIST ALOFT TODAY AS AN UPPER LEVEL TROUGH
MOVES INTO THE REGION. AT THE SURFACE, A FRONTAL SYSTEM WILL BRING
WIDESPREAD RAIN TO WESTERN WASHINGTON TODAY. CURRENT CONDITIONS
REMAIN VFR EARLY THIS MORNING, BUT EXPECT RAIN TO GRADUALLY PUSH
INLAND THROUGHOUT THE DAY AND TO SLOWLY BRING CONDITIONS DOWN TO
MVFR, AND EVEN LOCALIZED IFR/LIFR, ACROSS THE AREA TERMINALS. RAIN
LOOKS TO MOVE INLAND ALONG THE COAST BETWEEN 14-17Z AND MAKE ITS WAY
INTO INTO THE INTERIOR BETWEEN 18-21Z. CONDITIONS LOOK TO DROP DOWN
TO MVFR ACROSS THE CENTRAL AND SOUTHERN SOUND TERMINALS AFTER 21Z,
WITH LOWER CIGS AND VIS LIKELY PERSISTING THROUGH THE EVENING AND
INTO TUESDAY. TEMPORARY REDUCTIONS TO IFR/LIFR WILL BE POSSIBLE IN
ANY HEAVIER RAIN THROUGHOUT THE DAY. SOUTHEASTERLY WINDS WILL
PERSIST THROUGH THE MORNING, BEFORE INCREASING TO 8-12 KT AND
BECOMING MORE SOUTHWESTERLY BY THE AFTERNOON.
KSEA...VFR CONDITIONS WILL PERSIST THROUGH THE MORNING HOURS.
RAIN WILL MOVE INTO THE TERMINAL BETWEEN 19-21Z AND WILL ALLOW FOR
CONDITIONS TO DROP DOWN TO MVFR AFTER 21Z TODAY. WINDS OUT OF THE SE
THIS MORNING BETWEEN 4-8 KT WILL SHIFT TO THE SW THIS AFTERNOON AND
INCREASE TO 8-12 KT. WINDS WILL BECOME BREEZY OVERNIGHT INTO
TUESDAY, WITH GUSTS TO 25 KT POSSIBLE AT TIMES. MVFR CONDITIONS WILL
LIKELY PERSIST AT THE TERMINALS THROUGH TUESDAY MORNING.
14
MARINE
A SURFACE LOW AND ITS ASSOCIATED FRONTAL SYSTEM WILL MOVE ACROSS THE
COASTAL WATERS THIS MORNING, GRADUALLY PUSH ONSHORE, AND WEAKEN THIS
AFTERNOON AND EVENING. THIS SYSTEM WILL BRING GUSTY SOUTHEASTERLY
WINDS TO THE COASTAL WATERS THROUGH THIS AFTERNOON HOURS TODAY.
STRONG ONSHORE FLOW IS LIKELY TO DEVELOP IN THE WAKE OF THE SYSTEM,
WITH THE LATEST HREF PROBABILITIES INDICATING A 50-70% CHANCE OF
GALES DEVELOPING ALONG THE CENTRAL AND EASTERN STRAIT OF JUAN DE
FUCA ON TUESDAY. SOUTHERLY WINDS WILL INCREASE AND BECOME BREEZY FOR
PORTIONS OF THE PUGET SOUND WATERS ON TUESDAY MORNING AS WELL,
BEFORE EASING LATER TUESDAY NIGHT.
HIGH PRESSURE WILL REBUILD BACK INTO THE COASTAL WATERS ON WEDNESDAY
AND THURSDAY, WHILE A THERMAL TROUGH GRADUALLY EXPANDS NORTHWARD
ALONG THE OREGON COAST. NORTHWESTERLY WINDS OVER THE OUTER COASTAL
WATERS COULD BECOME BREEZY AT TIMES THE SECOND HALF OF THE WEEK AS A
RESULT. THE THERMAL TROUGH WILL THEN EXPAND NORTHWARD ALONG THE
WASHINGTON COAST BY THE WEEKEND, ALLOWING FOR FLOW TO TURN OFFSHORE.
SEAS WILL GENERALLY HOVER BETWEEN 6-9 FT THROUGH THE FIRST PART OF
THE WEEK, BEFORE SUBSIDING TOWARDS 5-7 FT NEAR MIDWEEK AND REMAINING
AT THIS RANGE HEADING INTO THE WEEKEND.
14
FIRE WEATHER
AS UPPER LEVEL RIDGING BUILDS INTO THE AREA
STARTING THURSDAY, CONDITIONS, INCLUDING FUELS, WILL NEED TO BE
MONITORED AS TEMPERATURES ARE EXPECTED TO CLIMB TO ABOVE NORMAL
VALUES BY THE END OF THE EXTENDED FORECAST PERIOD. GIVEN THE
STEEP CLIMB IN TEMPERATURES, EXTRA CAUTION WOULD BE ADVISED IN
ANY PLANNING DURING THIS TIME. CURRENT NBM MINIMUM RELATIVELY
HUMIDITY VALUES ARE RUNNING IN THE 25-35 PERCENT RANGE BY DAY 7
ACROSS PORTIONS OF THE AREA, BUT LOWER VALUES ARE ENTIRELY WITHIN
THE REALM OF POSSIBILITY. IF THE CROSS CASCADE GRADIENT GOES
NEGATIVE BY SUNDAY AS ADVERTISED IN A NUMBER OF MODELS, HUMIDITY
VALUES DROPPING INTO THE TEENS IN THE CASCADES VALLEYS AND PORTIONS
OF THE SOUTHWEST INTERIOR BECOME A DISTINCT POSSIBILITY.
27/18
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR
CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA-EAST ENTRANCE
U.S. WATERS STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR COASTAL
WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-
COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE OUT
10 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE
SHOALWATER OUT 10 NM.
SMALL CRAFT ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR COASTAL
WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-
COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO
60 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE
SHOALWATER 10 TO 60 NM.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page