648
FXUS66 KSEW 082217
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
317 PM PDT FRI MAY 8 2026
SYNOPSIS
CLOUDY AND MILD CONDITIONS WILL CONTINUE THROUGH THE WEEKEND AND
INTO EARLY NEXT WEEK AS HIGH PRESSURE REMAINS SITUATED OVER THE
WEST. A WEAK SYSTEM WILL CLIP THE NORTHERN PORTION OF WESTERN
WASHINGTON ON SUNDAY, BRINGING LITTLE MORE THAN DRIZZLE AND
OVERCAST SKIES. FORECAST CONFIDENCE DECREASES INTO THE MIDDLE OF
NEXT WEEK, WITH CHANCES FOR LIGHT RAIN THROUGH THE REMAINDER OF
THE WEEK.
SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/
A WEAK SPLITTING FRONTAL SYSTEM WILL CONTINUE TO PROGRESS
EASTWARD TODAY, BRINGING IN LITTLE MORE THAN CLOUDS AND ISOLATED
DRIZZLE TO WESTERN WASHINGTON. TEMPERATURES HAVE STAYED ON THE
COOL SIDE THIS MORNING, WITH SOME SUN BREAKS THIS AFTERNOON
HELPING TEMPERATURES TO PEAK IN THE LOW TO MID 60S ACROSS THE
LOWLANDS.
HIGH PRESSURE WILL BUILD INLAND BEHIND THE FRONTAL PASSAGE
TONIGHT INTO SATURDAY, WITH PERSISTENT CLOUDY SKIES AND DRIER
CONDITIONS. HIGHS WILL WARM A FEW DEGREES, TOPPING OUT IN THE
UPPER 60S TO LOW 70S.
THE UPPER LEVEL RIDGE WILL SHIFT EAST OF THE CASCADES BY
SATURDAY NIGHT, WITH SOUTHWEST FLOW ALOFT FILLING IN BEHIND.
ONSHORE FLOW WILL BRING INCREASED CLOUDS SUNDAY AS A WEAK
SYSTEM TO THE NORTH SKIRTS VANCOUVER ISLAND. CHANCES FOR
LIGHT RAIN WILL LIKELY BE CONFINED TO THE NORTHWESTERN COAST OF
THE OLYMPIC PENINSULA AND NORTH CASCADES, WITH OVERCAST
CONDITIONS ELSEWHERE. THE INCREASED CLOUD COVER WILL LOWER
TEMPERATURES A FEW DEGREES ON SUNDAY, WITH HIGHS MOSTLY IN THE
60S.
LONG TERM /MONDAY THROUGH FRIDAY/
MODELS REMAIN IN GOOD AGREEMENT OVER HIGH PRESSURE BUILDING OVER
THE WESTERN US EARLY NEXT WEEK, ALLOWING FOR MORE SUNBREAKS AND
WARMER CONDITIONS ON MONDAY AND TUESDAY. WHILE SOME ENSEMBLE
MEMBERS KEEP WESTERN WASHINGTON DRY THROUGH THE FIRST HALF OF
NEXT WEEK, SOME MEMBERS ARE PICKING UP ON A POTENTIAL CUTOFF LOW
DEVELOPING OFFSHORE AND QUICKLY SWINGING INLAND ON TUESDAY,
WITH POTENTIAL FOR SHOWERS FORMING MAINLY OVER HIGHER TERRAIN.
FORECAST CONFIDENCE DECREASES INTO THE MIDDLE OF NEXT WEEK, WITH
ENSEMBLES SHOWING A LARGE VARIANCE OF POSSIBLE WEATHER SYSTEMS
MOVING INTO THE AREA. CHANCES FOR LIGHT RAIN REMAIN ACROSS THE
REGION THROUGH THE END OF NEXT WEEK, WITH SNOW LEVELS REMAINING
ABOVE 6000-7000 FEET.
15
AVIATION
WEST TO SOUTHWEST FLOW ALOFT AS A SHORTWAVE TROUGH PASSES,
FOLLOWED BY A BUILDING UPPER-RIDGE. VFR CIGS AREA-WIDE THIS
AFTERNOON. A WEAK FRONT IS TRACKING ACROSS THE AREA, BRINGING SW
SURFACE WINDS WITH GUSTS UP TO 15-20 KT. GUSTS DECREASE AFTER
00-02Z AS WINDS BECOME LIGHT OVERNIGHT. VFR (MVFR AT THE COAST)
FOR MUCH OF THE EVENING BUT LOW-LEVEL MOISTURE WILL HANG AROUND
WITH THE POTENTIAL FOR AREAS OF MVFR POSSIBLE INTO THE EARLY
MORNING HOURS ON SATURDAY. VFR AGAIN TO DEVELOP BY SATURDAY
AFTERNOON.
KSEA...VFR CONDITIONS CURRENTLY AND MUCH OF TONIGHT. SOUTHWESTERLY
WIND GUSTS UP TO 20 KT DECREASING AROUND 00-02Z THIS EVENING. A 30-
35% CHANCE OF MVFR CIGS BETWEEN 12-18Z SATURDAY. VFR THEREAFTER.
41
MARINE
A WEAK FRONT IS PUSHING ACROSS AREA WATERS THIS EVENING WITH LITTLE
TO NO POTENTIAL FOR HEADLINES. REOCCURRING SPELLS OF ONSHORE FLOW
INTO EARLY NEXT WEEK. THE NEXT BEST CHANCE OF SCA OCCURING ARE FOR
THE CENTRAL/EASTERN STRAIT DUE TO A WESTERLY PUSH ON SUNDAY EVENING.
MUCH UNCERTAINTY GOING INTO NEXT WEEK BUT, A MORE ORGANIZED SYSTEM
IS SET TO ARRIVE BY WEDNESDAY. SEAS 3 TO 6 FT TONIGHT THROUGH EARLY
NEXT WEEK.
41
HYDROLOGY
THE DAILY HYDROLOGY DISCUSSION HAS ENDED UNTIL THE START OF THE NEXT
RAINY SEASON; IT WILL ONLY BE UPDATED DURING THIS TIME AS NEEDED.
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...NONE.
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