119
FXUS66 KSEW 041751
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
1051 AM PDT MON MAY 4 2026
SYNOPSIS
UPPER LEVEL RIDGE OVER WESTERN WASHINGTON THROUGH
THURSDAY SHIFTING EAST THURSDAY NIGHT. DISSIPATING FRONT TRYING
TO MOVE INTO THE AREA LATER FRIDAY INTO SATURDAY MORNING.
ANOTHER UPPER LEVEL RIDGE BUILDS SATURDAY AFTERNOON INTO SUNDAY.
LOW LEVEL FLOW TURNING ONSHORE TODAY WITH VARYING DEGREES OF
ONSHORE FLOW THROUGH MOST OF THE WEEK.
SHORT TERM /TODAY THROUGH WEDNESDAY/
SATELLITE IMAGERY SHOWS
STRATUS SURGING UP THE COASTLINE HAS REACHED THE GRAYS
HARBOR/PACIFIC COUNTY BORDER AT 2 AM/09Z. A FEW HIGH CLOUDS OVER
THE REMAINDER OF THE AREA. TEMPERATURES WERE IN THE 50S AND
LOWER 60S.
STRATUS WILL CONTINUE MOVING UP THE COASTLINE REACHING THE NORTH
COAST THIS AFTERNOON. OUTSIDE OF THE GRAYS HARBOR AREA THE
STRATUS WILL REMAIN NEAR THE BEACHES. LIGHT FLOW IN THE LOWER
LEVELS THIS MORNING BECOMING ONSHORE LATER THIS MORNING INTO THE
AFTERNOON. THE MARINE LAYER WILL BE TOO SHALLOW TO GET EAST OF
PUGET SOUND WITH HIGHS SIMILAR TO SUNDAY'S READINGS, IN THE 70S
AND LOWER 80S. THE MARINE AIR WILL FILTER INTO THE LOWER
CHEHALIS VALLEY, SOUTHERN HOOD CANAL AND PORTIONS OF THE
SOUTHWEST INTERIOR COOLING HIGHS ABOUT 5 DEGREES FROM YESTERDAY.
HIGHS IN THESE LOCATIONS IN THE 70S TO LOWER 80S AS WELL.
SIGNIFICANT COOLING ALONG THE COAST WITH HIGHS IN THE MID TO
UPPER 60S. WARMER TEMPERATURES ALONG THE NORTH COAST.
LOW LEVEL ONSHORE FLOW PEAKING TONIGHT WITH THE MARINE LAYER
GETTING INTO THE PUGET SOUND AREA BY EARLY TUESDAY MORNING. LOWS
IN THE MID 40S TO MID 50S.
ONSHORE GRADIENTS GOING LIGHT DURING THE DAY TUESDAY WITH THE
MARINE LAYER RETREATING TO THE COASTLINE BY AFTERNOON. THE WEAK
MARINE PUSH WILL LOWER HIGHS BY ABOUT 5 DEGREES OVER THE
INTERIOR, INTO THE UPPER 60S TO MID 70S. MARINE LAYER REMAINING
INTACT ALONG THE COAST KEEPING HIGHS IN THE LOWER 60S.
LITTLE CHANGE IN THE PATTERN TUESDAY NIGHT INTO WEDNESDAY WITH
AN UPPER LEVEL RIDGE OVER THE AREA AND LIGHT LOW LEVEL ONSHORE
FLOW. LOWS IN THE MID 40S TO MID 50S. HIGHS WEDNESDAY A LITTLE
COOLER AGAIN OVER THE INTERIOR, MID 60S TO LOWER 70S WHILE ALONG
THE COAST HIGHS NEAR 60. FELTON
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
EXTENDED MODELS
STILL SHOWING GOOD CONSISTENCY. UPPER LEVEL RIDGE OVER THE AREA
WEDNESDAY NIGHT AND THURSDAY SHIFTING EAST THURSDAY NIGHT.
DISSIPATING NEGATIVELY TILTED FRONT FALLING APART OVER WESTERN
WASHINGTON LATER FRIDAY INTO SATURDAY MORNING. SLIGHT CHANCE OF
SHOWERS IN THIS WINDOW. ANOTHER UPPER LEVEL RIDGE BUILDING OVER
THE AREA SATURDAY AFTERNOON INTO SUNDAY. HIGHS IN THE 60S AND
LOWER 70S THURSDAY COOLING INTO THE UPPER 50S TO MID 60S FRIDAY.
WARMING TREND FOR THE WEEKEND WITH 60S AND LOWER 70S SATURDAY
AND MID 60S TO MID 70S SUNDAY.
AVIATION
NORTH TO NORTHEAST FLOW ALOFT CONTINUES WITH AN
UPPER RIDGE LOCATED OFFSHORE WITH SOUTHWESTERLY SURFACE FLOW 5-9
KTS AREA WIDE. VFR CONDITIONS WILL PREVAIL ACROSS THE INTERIOR
TODAY. STRATUS WILL SPREAD INTO THE INTERIOR LATE TONIGHT WITH
IFR CONDITIONS EXPECTED ACROSS MUCH OF THE INTERIOR LOWLANDS ON
TUESDAY MORNING.
KSEA...VFR TODAY. IFR STRATUS EXPECTED TO RETURN AROUND 12Z-14Z
TUESDAY, BREAKING OUT MORE COMPLETELY AFTER 16Z. SURFACE WIND LIGHT
AND VARIABLE BECOMING W/SW 7 TO 10 KNOTS THIS AFTERNOON THEN LIGHT
SOUTHERLY TONIGHT.
27/21
MARINE
A THERMAL TROUGH WILL SHIFT INLAND TODAY FOR A RETURN
TO ONSHORE FLOW. VARYING DEGREES OF ONSHORE FLOW WILL THEN
PERSIST THROUGH THE WEEK AS A SURFACE RIDGE REMAINS ANCHORED
OFFSHORE WITH LOWER PRESSURE INLAND. SMALL CRAFT ADVISORY
WESTERLIES ARE LIKELY IN THE CENTRAL/EAST STRAIT EACH OF THE
NEXT SEVERAL AFTERNOONS AND EVENINGS.
27/21
HYDROLOGY
NO RIVER FLOODING IN THE NEXT 7 DAYS.
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 5 AM PDT
TUESDAY FOR CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA-
EAST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
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