278
FXUS66 KSEW 111556
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
856 AM PDT FRI SEP 11 2026
SYNOPSIS
TROUGHING DEVELOPING OVER THE AREA WILL CONTINUE INTO THIS
WEEKEND, BRINGING UNSETTLED CONDITIONS AND COOLER TEMPERATURES
TO THE REGION. RIDGING LOOKS TO REBUILD THROUGH THE FIRST HALF
OF NEXT WEEK FOR A SLOW WARMING TREND.
SHORT TERM /TODAY THROUGH SUNDAY/
NO SIGNIFICANT CHANGES TO THE SHORT/LONG TERM AFD THIS MORNING.
-HPR
AN UPPER LEVEL TROUGH OVER THE REGION WILL CONTINUE TO BRING
ONSHORE FLOW, COOLER TEMPERATURES, AND UNSETTLED WEATHER TO
WESTERN WASHINGTON OVER THE NEXT COUPLE OF DAYS. IT'LL DEEPEN
TODAY AS ITS ASSOCIATED UPPER-LOW FORMS OFF THE BC COAST AND
POSITIONS OFFSHORE BY THIS EVENING. AS A RESULT, LIGHT SHOWER
ACTIVITY IS POSSIBLE OVER THE OLYMPIC PENINSULA TONIGHT BUT
CONDITIONS ARE TO REMAIN MOSTLY DRY ACROSS THE AREA. HIGHS TODAY
WILL TOP OUT IN THE 60S TO NEAR 70 F WITH OVERNIGHT LOWS IN THE
50S.
THE UPPER-LOW WILL TRAVERSE ACROSS THE REGION ON SATURDAY,
BRINGING WIDESPREAD RAIN, SHOWERS AND A 15-20% CHANCE FOR
THUNDERSTORMS. THE HIGHEST PROBABILITY FOR LIGHTNING IS OVER THE
OLYMPICS AND SOUTHWEST INTERIOR ACCORDING TO THE NBM. IT'LL HANG
AROUND THROUGH SUNDAY WITH CONTINUED PRECIPITATION CHANCES BUT
THE THUNDERSTORM THREAT WILL DIMINISH WITH PROBABILITIES LESS
THAN 10%. HIGH TEMPERATURES RANGING BETWEEN THE 60S TO NEAR 70 F
AND LOWS MAINLY IN THE 50S FOR BOTH SATURDAY AND SUNDAY.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/
CONDITIONS ARE FAVORED TO TREND DRIER SUNDAY NIGHT AS THE LOW
CENTER CROSSES EAST OF THE CASCADES. CAN'T RULE OUT LINGERING
SHOWERS OVER THE MOUNTAINS. AN UPPER LEVEL RIDGE WILL BEGIN
TO BUILD OFFSHORE ON MONDAY, INTRODUCING A SLOW WARMING TREND
THROUGH MIDWEEK. SOME ENSEMBLES SUGGEST WEAK TROUGHING
TUESDAY-THURSDAY THAT COULD BRING SOME POPS TO THE REGION, BUT
FOR NOW, LOOKS LIKE DRY AND WARM CONDITIONS WILL MANIFEST.
AVIATION
A MIX OF VFR AND MVFR CIGS THIS MORNING. EXPECTING WIDESPREAD VFR
FOR ALL TERMINALS AFTER 19Z, CONTINUING INTO SATURDAY MORNING.
SOUTHERLY WINDS THIS MORNING, WILL TRANSITION NORTHERLY THIS
EVENING. CALM TO LIGHT NORTHERLY WINDS OVERNIGHT. VISIBILITY
REDUCTIONS POSSIBLE (20% CHANCE) SATURDAY MORNING ACROSS PORTIONS OF
THE SOUTHERN INTERIOR.
KSEA...CURRENTLY VFR AT THE TERMINAL THIS MORNING, BUT HAVE OPTED TO
TREND IT MVFR THROUGH 19Z DUE TO LOW CLOUDS LINGERING WITHIN THE
VICINITY. SOME HIGH-RES GUIDANCE IS ALSO FAVORING THE LOW CLOUDS
PERSISTING THIS MORNING. AS A RESULT, MAY SEE SOME CIGS BOUNCING
AROUND THIS MORNING, UNTIL THEY LIFT TO VFR THIS AFTERNOON. VFR
CONDITIONS WILL CONTINUE INTO SATURDAY. SSE WINDS THIS MORNING WILL
TRANSITION MORE SSW THIS AFTERNOON AROUND 6-8 KT. WINDS SWITCH
NORTHERLY THIS EVENING AFTER 03Z AROUND 4-6 KT.
29
MARINE
HIGH PRESSURE OVER THE WATERS WILL WEAKEN TODAY. A WEAK SYSTEM
WILL MOVE THROUGH THE OFFSHORE WATERS INTO OREGON TONIGHT AND
SATURDAY. HIGH PRESSURE WILL REBUILD OVER THE COASTAL WATERS
SUNDAY AND REMAIN THROUGH TUESDAY.
POSSIBLE SMALL CRAFT ADVISORY WINDS IN THE CENTRAL AND EASTERN
STRAIT OF JUAN DE FUCA SATURDAY NIGHT.
SEAS 5 TO 7 FEET TODAY AND A LITTLE CHOPPY. SEAS SUBSIDING TO 3
TO 5 FEET SATURDAY WITH 3 TO 5 FOOT SEAS CONTINUING INTO THE
FIRST HALF OF NEXT WEEK. FELTON
FIRE WEATHER
A RETURN TO ONSHORE FLOW WILL MAINTAIN COOLER AND MORE MOIST
CONDITIONS ACROSS WESTERN WASHINGTON THROUGH THE WEEKEND. LIGHT
PRECIPITATION IS LIKELY INTO SATURDAY AS ANOTHER WEAK SYSTEM
MOVES OVER THE REGION WITH A SLIGHT CHANCE (15-20%) OF
THUNDERSTORMS. CONDITIONS ARE EXPECTED TO GRADUALLY WARM AND
DRY INTO NEXT WEEK, THOUGH FIRE WEATHER CONCERNS REMAIN LOW AT
THIS TIME.
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...NONE.
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