704
FXUS66 KSEW 030304
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
804 PM PDT SAT MAY 2 2026
SYNOPSIS
WEAK UPPER-LOW OFF THE OREGON COAST MOVING SOUTHWARD TONIGHT.
UPPER LEVEL RIDGE BUILDING INTO THE BRITISH COLUMBIA COAST
SUNDAY WILL PROGRESS OVER WESTERN WASHINGTON BY TUESDAY.
RIDGING WILL VARY IN INTENSITY THROUGH MIDWEEK BEFORE EXITING ON
FRIDAY. TEMPERATURES REMAINING ABOVE AVERAGE THROUGH MUCH OF
THE UPCOMING WEEK.
SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/
THE LATEST FORECAST REMAINS ON TRACK WITH NO UPDATES THIS
EVENING. AN UPPER- RIDGE IS NOSING INTO BRITISH COLUMBIA AS AN
UPPER- LOW FLOATS OFF THE COAST OF OREGON AND NORCAL. FOR
TONIGHT, CONDITIONS WILL TREND DRIER AREA-WIDE AS THE
AFOREMENTIONED UPPER-LOW TRACK SOUTHWARD AND AWAY. OVERNIGHT
LOWS WILL BOTTOM OUT INTO THE LOWER TO MID 50S.
THE HEAT WILL INTENSIFY ON SUNDAY AND MONDAY. UPPER-RIDGING
WILL SHIFT EVER SO GENTLY OVER THE REGION, ALLOWING FOR MORE
LARGE- SCALE SUBSIDENCE ACROSS THE PNW. IN CONCERT, A SURFACE
THERMAL TROUGH WILL BUILD ALONG THE COAST ON SUNDAY AS WELL,
BRINGING A LIGHT SPELL OF OFFSHORE FLOW. HIGH TEMPERATURES WILL
TOP OUT WELL INTO THE UPPER 70S AND 80S ACROSS THE INTERIOR ON
BOTH DAYS. A MARINE PUSH WILL USHER IN SOME NATURAL AC BY MONDAY
EVENING AS THE COAST AND ADJACENT AREAS COOL-DOWN INTO THE 60S.
THE HEATRISK FOR THE MOST PART REMAINS IN THE MINOR CATEGORY
SUNDAY AND MONDAY DUE TO THE TEMPERATURES COOLING OFF NICELY IN
THE OVERNIGHT HOURS. AREAS OF MODERATE HEATRISK IS IN THE
FORECAST FOR INLAND PORTIONS OF GRAYS HARBOR COUNTY NEARBY
LOCATIONS PRIMARILY ON SUNDAY.
41
LONG TERM /TUESDAY THROUGH SATURDAY/
AS MENTIONED, LOW-LEVEL ONSHORE FLOW WILL INCREASE ON MONDAY
NIGHT. WIDESPREAD MARINE STRATUS IS EXPECTED INTO TUESDAY AS THE
COOL-DOWN ENSUES. DAYTIME HIGHS ARE EXPECTED TO BE IN THE UPPER
60S TO MID 70S. COAST REMAINING IN THE MID 60S.
UPPER LEVEL RIDGE OVER THE AREA WEAKENING WEDNESDAY, REBUILDING
THURSDAY THEN STARTS TO MOVE EAST FRIDAY. LOW LEVEL FLOW
REMAINING LIGHT ONSHORE. RELATIVELY WARM AIR ALOFT COMBINED WITH
ONLY A SHALLOW MARINE LAYER OVER THE INTERIOR IN THE LATE NIGHT
AND MORNING HOURS WILL KEEP DAYTIME HIGHS ABOVE NORMAL THROUGH
THE WEEK. A LITTLE COOLING FRIDAY AS THE RIDGE STARTS TO EXIT
THE AREA. HIGHS WEDNESDAY AND THURSDAY IN THE 60S TO LOWER 70S,
BEFORE SETTLING INTO THE 60S AREA WIDE ON FRIDAY. LOWS IN THE
40S.
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AVIATION
NORTHERLY FLOW ALOFT WILL DEVELOP THIS EVENING THROUGH SUNDAY
AS AN UPPER RIDGE BEGINS TO DEVELOP OFFSHORE. VFR CONDITIONS
THIS AFTERNOON WITH A FEW HIGH CLOUDS AND CUMULUS DEVELOPMENT
OVER THE CASCADES. VFR CONDITIONS WITH MAINLY CLEAR SKIES WILL
CONTINUE THROUGH SUNDAY. N/NW SURFACE WINDS THIS AFTERNOON
REMAINING BREEZY AROUND PUGET SOUND WITH SUSTAINED WINDS RANGING
7 TO 12 KTS AND LOCALIZED GUSTS TO 20 KT. WINDS WILL BECOME
LIGHTER TONIGHT, MAINLY FROM THE N/NE. WINDS PICK UP SUNDAY AT
JUST A TOUCH LIGHTER COMPARED TO TODAY.
KSEA...VFR CONDITIONS THROUGH THE TAF PERIOD WITH HIGH CLOUDS AT
TIMES. N/NW SURFACE WINDS RANGING 8 TO 13 KTS THIS AFTERNOON WITH
GUSTS TO 20 KTS. NE WINDS TONIGHT INTO SUNDAY FROM 7 TO 10 KTS.
JD/HPR
MARINE
THERMALLY INDUCED SURFACE TROUGH WILL BUILD NORTHWARD ALONG THE
COAST INTO SUNDAY WITH WEAK NORTHERLY, OFFSHORE FLOW
DEVELOPING. THE THERMAL TROUGH WILL SHIFT INTO THE INTERIOR ON
MONDAY ALLOWING STRONG ONSHORE FLOW TO DEVELOP DURING THE
EVENING AND RESUME INCREASE TOWARD THE MIDDLE OF NEXT WEEK.
WESTERLIES IN THE CENTRAL AND EAST STRAIT WILL LIKELY APPROACH
STRONG SCA TO GALE FORCE GUSTS MONDAY NIGHT INTO TUESDAY MORNING.
41
HYDROLOGY
NO RIVER FLOODING IN THE NEXT 7 DAYS.
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...NONE.
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