068
FXUS66 KSEW 080908
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
208 AM PDT TUE SEP 8 2026
SYNOPSIS
HIGH PRESSURE WILL MOVE IN TUESDAY AND WEDNESDAY
FOR DRIER AND WARMER CONDITIONS. A PAIR OF SYSTEMS LOOK TO MOVE
THROUGH THURSDAY THROUGH THE WEEKEND FOR MORE CHANCES FOR
SHOWERS AND COOLER WEATHER.
SHORT TERM /TODAY THROUGH THURSDAY/
DRY AND WARMER WEATHER
WILL PREVAIL THROUGH WEDNESDAY WITH WEAK HIGH PRESSURE OVER THE
REGION. MAX TEMPERATURES WILL PEAK ON WEDNESDAY WITH HIGHS IN
THE MID 70S TO LOWER 80S. THE COAST WILL BE COOLER AND IN THE
60S.
BROAD LOW PRESSURE OVER WESTERN CANADA WILL SAG SOUTH AND SEND A
TROUGH THROUGH WESTERN WA ON THURSDAY. THE RESULT WILL BE
INCREASING CLOUDS, COOLER CONDITIONS, A CHANCE OF SHOWERS
(MAINLY CENTRAL AND NORTHERN CASCADES). 33
LONG TERM /THURSDAY NIGHT THROUGH MONDAY/
LOW PRESSURE
REMAINS OVER THE PAC NW FRIDAY THROUGH THE WEEKEND AS A CLOSED
LOW DROPS DOWN FROM CANADA. THIS WILL KEEP WESTERN WA COOL AND
SHOWERY THROUGH THE PERIOD. EXPECT HIGHS IN THE 60S WITH
OVERNIGHT LOWS AROUND 50. LOOK FOR DRY AND MILD CONDITIONS EARLY
NEXT WEEK WITH TEMPERATURES CLOSE TO AVERAGE. 33
AVIATION
VFR ACROSS MOST WESTERN WASHINGTON TERMINALS EARLY
THIS MORNING, WITH IFR LOW STRATUS DEVELOPING ALONG THE COAST.
THE STRATUS LAYER WILL SLOWLY EXPAND INLAND THIS MORNING, BUT IS
NOT EXPECTED TO IMPACT TERMINALS EAST OF THE PUGET SOUND.
STRATUS IS ALSO FAVORED TO DEVELOP OVER THE NORTHERN TERMINALS
THIS MORNING, INCLUDING KBLI AND KPAE. PATCHY FOG WILL ALSO
DEVELOP THIS MORNING, POTENTIALLY IMPACTING KPWT AND KOLM. ANY
FOG AND STRATUS THAT FORMS OVER THE INTERIOR WILL BE GENERALLY
SHALLOW, AND IS EXPECTED TO BURN OFF BY THE AFTERNOON, REVEALING
VFR CONDITIONS. ANOTHER ROUND OF MARINE STRATUS IS EXPECTED TO
BRING WIDESPREAD MVFR TO IFR ONCE AGAIN EARLY WEDNESDAY MORNING,
BUT IS CURRENTLY FAVORED TO REMAIN WEST OF KSEA/KBFI.
KSEA...VFR EARLY THIS MORNING, WITH POTENTIAL FOR LOW CLOUDS AND
PATCHY FOG NEAR THE TERMINAL BUT DETERIORATED CONDITIONS AT SEA ARE
UNLIKELY. NORTHERLY WINDS WILL GENERALLY REMAIN LIGHT THROUGH
WEDNESDAY MORNING AT AROUND 4 TO 8 KT.
15
MARINE
HIGH PRESSURE WILL CONTINUE TO BUILD OVER THE COASTAL
WATERS THROUGH WEDNESDAY. NORTH TO NORTHWEST WINDS WILL
GRADUALLY INCREASE INTO WEDNESDAY AS A FRONTAL SYSTEM SLOWLY
APPROACHES, WITH POTENTIAL FOR SMALL CRAFT WESTERLIES THROUGH
THE STRAIT OF JUAN DE FUCA WEDNESDAY EVENING THROUGH THURSDAY
MORNING. THE FRONTAL SYSTEM WEAKENS AS IT MOVES THROUGH THE
REGION ON THURSDAY, ALLOWING WINDS TO EASE ACROSS THE REGION.
ANOTHER WEATHER SYSTEM MAY MOVE OVER THE WATERS LATE FRIDAY INTO
SATURDAY, BUT NO HEADLINE WINDS ARE ANTICIPATED AT THIS TIME.
SEAS AROUND 4 TO 5 FEET WILL GRADUALLY BUILD THROUGH WEDNESDAY,
REACHING 7 TO 10 FEET BY THURSDAY AFTERNOON. THIS WILL ALSO BRING
STEEP SEAS AS SHORT PERIOD WAVES FROM THE STRONGER WINDS OVER THE
COASTAL WATERS BEGIN TO DOMINATE. SEAS WILL EASE TO AROUND 5 TO 6
FEET BY FRIDAY AND CONTINUE TO STAY NEAR 5 FEET THROUGH THE WEEKEND.
15
FIRE WEATHER
HIGH PRESSURE THROUGH WEDNESDAY WILL BRING
BRIEF ELEVATED FIRE WEATHER CONCERNS ALONGSIDE A GRADUAL WARMING
AND DRYING TREND, WITH WEAK OFFSHORE FLOW TUESDAY NIGHT
LIMITING OVERNIGHT RELATIVE HUMIDITY RECOVERIES ALONG THE
WESTERN CASCADES. ADDITIONAL DRYING THROUGHOUT THE DAY WEDNESDAY
WILL BRING MINIMUM RELATIVE HUMIDITY VALUES OVER THE CASCADES
TO THE 25 TO 35 PERCENT RANGE, NEARING CRITICAL THRESHOLDS IN
SOME AREAS NEAR THE CASCADE CREST.
BY THURSDAY, FIRE WEATHER CONCERNS ACROSS WESTERN WASHINGTON SUBSIDE
AS AN UPPER LEVEL TROUGH BRINGS STRONGER ONSHORE FLOW. ALTHOUGH THIS
SYSTEM WILL NOT BRING MUCH IN THE WAY OF PRECIPITATION, RELATIVE
HUMIDITIES WILL REBOUND WITH MUCH HIGHER OVERNIGHT RECOVERIES.
15
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...NONE.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page