277
FXUS66 KSEW 101604
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
904 AM PDT WED SEP 10 2025
SYNOPSIS
AN UPPER LOW SOUTH OF THE AREA WILL CONTINUE TO
WEAKEN AND SHIFT EASTWARD. THIS WILL SPREAD MOISTURE INTO THE
REGION, WITH SHOWERS AND ISOLATED THUNDERSTORMS DEVELOPING NEAR
THE CASCADES AND MOVING INTO THE REGION. WEAK HIGH PRESSURE
THURSDAY AND FRIDAY WILL BRING SOME DRIER CONDITIONS, BUT
ANOTHER DISTURBANCE BRINGS A RETURN OF RAIN TO THE REGION LATE
IN THE WEEKEND.
UPDATE
OTHER THAN SOME PATCHY ISOLATED FOG AND LOW CLOUDS,
IT'S A QUIET MORNING ACROSS THE REGION. THOSE CLOUDS/FOG SHOULD
BURN OFF AS WE GO THROUGH THE DAY, EXCEPT PERHAPS ALONG THE
COAST WHERE THE CLOUDS WILL HUG THE COASTLINE BY THIS AFTERNOON.
THE CURRENT FORECAST IS IN GOOD SHAPE AND NO UPDATES ARE
PLANNED. -WOLCOTT-
SHORT TERM /TODAY THROUGH FRIDAY/
AN UPPER LEVEL LOW CONTINUES
TO SPIN OVER THE PAC NW TODAY. SHOWERS ARE MOSTLY FOCUSED OVER
OREGON BUT WE WILL SEE ISOLATED ACTIVITY AND A FEW POSSIBLE
THUNDERSTORMS OVER THE CASCADES, NEAR THE CREST. DOWN IN THE
LOWLANDS, STRATUS CLOUDS WILL INCREASE IN COVERAGE BUT WE SHOULD
SEE SUNBREAKS THIS AFTERNOON. EXPECT HIGHS IN THE 70S WITH 60S
ALONG THE COAST.
THE UPPER LOW SLOWLY SHIFTS EAST ON THURSDAY BUT STILL REMAINS
OVER THE REGION. SHOWER COVERAGE IS AGAIN LIMITED TO THE CASCADES
WITH THUNDERSTORM CHANCES HIGHER EAST OF THE CREST. SURFACE LOW
PRESSURE WILL SHIFT INLAND FOR A STRONGER ONSHORE PUSH THURSDAY
NIGHT.
FRIDAY IS LOOKING DRY WITH HIGH PRESSURE ON THE BACKSIDE OF THE
LOW. TEMPERATURES WILL BE A LITTLE COOLER, THOUGH, WITH THICKER
STRATUS - MID 60S TO AROUND 70. 33
LONG TERM /SATURDAY THROUGH TUESDAY/
THE NEXT INCOMING PACIFIC
FRONTAL SYSTEM WILL STALL OFFSHORE ON SATURDAY, LEADING TO ONE
MORE DRY DAY. SHOWERS WILL THEN INCREASE IN COVERAGE ON SUNDAY AS
AN UPPER LEVEL TROUGH CUTS THROUGH. SHOWERS WILL LINGER INTO
MONDAY AS THE LOW DEPARTS. HIGH PRESSURE BUILDS ON TUESDAY FOR A
SLIGHT UPTICK IN TEMPERATURES. 33
AVIATION
AN UPPER LEVEL LOW WILL DIG SOUTHWARD INTO CALIFORNIA
TODAY AS A NORTHEAST-TILTED RIDGE STARTS TO AMPLIFY SLIGHTLY OVER
SOUTHWEST CANADA. THE FLOW WITH THIS PATTERN IS LIGHT NORTHEAST.
SHALLOW/PATCHY FOG CONTINUES BETWEEN EVERETT AND MT. VERNON, AND
ALSO FROM FAR SOUTHERN PUGET SOUND/KITSAP AREAS SOUTHWESTWARD. SOME
STRATUS (AROUND 4,000 FT) ALSO REMAINS OVER THE CASCADES AND OVER
THE COAST. VISIBILITIES AT SOME TERMINALS HAVE BEEN AS LOW AS 1/4
SM. GIVEN HOW HOW SHALLOW THE FOG/MIST IS, CLEARING WILL TAKE PLACE
BETWEEN 16-18Z THIS MORNING, RETREATING TO THE COAST. VFR/CLEAR
SKIES ARE EXPECTED REST OF TODAY WITH LIGHT NORTH WINDS AT AROUND 4-
6 KT. STRATUS APPEARS TO BE MORE WIDESPREAD TOMORROW, WITH A 25-35%
CHANCE OF IFR IN INTERIOR TERMINALS (10-20% CHANCE OF LIFR), AND THE
CHANCE OF VIS DROPPING TO LESS THAN 1 SM 5-10% OR LESS. WINDS
THURSDAY SHIFT TO THE SOUTHWEST IN THE MORNING 3-5 KT.
KSEA...NEARBY FOG TO THE SOUTH/WEST HAS REMAINED OUT OF THE TERMINAL
DUE TO STRATUS PASSING OVERHEAD FROM THE CASCADES. MAY STILL SEE
FEW005 DUE TO THE NEARBY LOW OBSCURITIES BUT THIS WILL BURN OFF
QUICKLY (BETWEEN 16-18Z) WITH VFR THE REST OF THE DAY. WINDS WILL
REMAIN LIGHT OUT OF THE NORTH 4-8 KT. EXPECTATION IS FOR STRATUS TO
BE MORE WIDESPREAD OVER THE TERMINAL THURSDAY MORNING, WITH THE
PROBABILITY OF IFR AT 25%. WINDS WILL BE LIGHT (BELOW 5 KT) TONIGHT
AND BECOME SOUTHWEST THURSDAY MORNING 4-6 KT.
HPR
MARINE
WEAK LOW PRESSURE OVER THE PACIFIC NORTHWEST WILL BEGIN TO
MOVE INLAND WEDNESDAY WITH STRONGER ONSHORE FLOW BEHIND THE SYSTEM
ON THURSDAY. THIS WILL ALLOW FOR A PUSH OF WESTERLIES DOWN THE
STRAIT OF JUAN DE FUCA THURSDAY AFTERNOON THAT MAY REACH SMALL CRAFT
ADVISORY STRENGTH, ESPECIALLY THROUGH THE CENTRAL STRAIT. HIGH
PRESSURE WILL TRY TO NOSE INTO THE AREA FRIDAY. A FRONT WILL BEGIN
TO APPROACH THE COASTAL WATERS SATURDAY NIGHT INTO SUNDAY, WITH
MODELS BEGINNING TO SUPPORT A LOW PRESSURE SYSTEM FORMING ALONG THE
FRONT AND MOVING INTO THE PACIFIC NORTHWEST ON SUNDAY. THERE'S STILL
CONSIDERABLE MODEL DISCREPANCIES ON WHERE EXACTLY THIS LOW WILL GO,
HOWEVER, EXPECT AN INCREASE IN WINDS AND WAVES THAT COULD REQUIRE
ADDITIONAL HEADLINES GOING INTO THE LATTER HALF OF THE WEEKEND. HIGH
PRESSURE LOOKS TO REDEVELOP FOR THE BEGINNING OF NEXT WEEK.
SEAS WILL GENERALLY REMAIN IN THE 4 TO 7 FT RANGE ACROSS THE AREA
THROUGH THE REST OF THE WEEK. SEAS WILL LIKELY RISE TO THE 6 TO 8 FT
RANGE GOING INTO THE WEEKEND, THOUGH COULD APPROACH 10 FT ON SUNDAY,
DEPENDING ON THE EVOLUTION OF THE PATTERN.
62
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...NONE.
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