411
FXUS66 KSEW 041649
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
949 AM PDT FRI JUL 4 2025
SYNOPSIS
SEASONABLY WARM WEATHER FOR THE 4TH OF JULY HOLIDAY
IS EXPECTED AS A WEAK TROUGH PUSHES THROUGH THE AREA. A WARMING
TREND IS EXPECTED BY EARLY NEXT WEEK AS A RIDGE OF HIGH PRESSURE
BUILD ACROSS THE WESTERN STATES. TEMPERATURES ARE TRENDING ABOVE
AVERAGE FOR BOTH MONDAY AND TUESDAY.
SHORT TERM /TODAY THROUGH SUNDAY/
DEBRIS CLOUDINESS FROM
CONVECTION OVER OREGON IS DRIFTING INTO THE AREA TODAY, BUT IT WILL
ONLY ACT TO FILTER THE SUNSHINE FROM TIME TO TIME WITH ANY STORM
DEVELOPMENT EXPECTED TO REMAIN EAST OF THE CASCADE CREST. NO
FORECAST UPDATES ARE ANTICIPATED THIS MORNING. PREVIOUS DISCUSSION
FOLLOWS WITH UPDATE TO AVIATION PORTION. 27
A WEAK TROUGH OFFSHORE IS ENTERING THE REGION AS ITS BASE NOSES INTO
OREGON AND NORTHERN CALIFORNIA. THUNDERSTORMS HAVE BEEN OBSERVED
WITH THIS DISTURBANCE BUT ARE WELL AWAY FROM THE CWA AS THEY TRACK
THROUGH CENTRAL OREGON AND THE REST OF THE INLAND NORTHWEST AS THE
DAY PROGRESS.
CAN'T RULE OUT A SLIGHT CHANCE (15%) OF SHOWERS OVER THE NORTH
CASCADES THIS AFTERNOON. OTHERWISE, A PLEASANT DAY IS IN STORE FOR
THE 4TH OF JULY HOLIDAY. SEASONAL TEMPERATURES ARE EXPECTED WITH
HIGHS FORECAST TO BE IN THE LOWER TO MID 70S ACROSS THE INTERIOR.
COASTAL AREAS GENERALLY IN THE 60S. TONIGHT, DRY CONDITIONS WILL
REMAIN AS THE AFOREMENTIONED TROUGH IS MODELED TO BE WELL EAST OF
THE CASCADES. OVERNIGHT LOWS WILL FALL INTO THE MID 40S TO LOWER
50S.
MORE ZONAL FLOW ALOFT SATURDAY INTO SUNDAY WITH DRY AND NEAR
NORMAL CONDITIONS FAVORED. A MODEST WARM UP WILL BE FELT ON SUNDAY
HOWEVER AS HEIGHTS RISE, INFLUENCED BY TROUGHING OFF THE COAST OF
CALIFORNIA AND HIGH PRESSURE OVER THE FOUR CORNERS REGION. HIGH
TEMPERATURES WILL AGAIN BE MOSTLY IN THE 70S BUT SOME 80S ARE
POSSIBLE TO CREEP UP THROUGH THE SW INTERIOR AND CASCADE VALLEYS
ON SUNDAY. OVERNIGHT LOWS IN THE 40S AND 50S.
LONG TERM /MONDAY THROUGH THURSDAY/
A WARMING TREND IS FAVORED
TO PERSIST INTO MONDAY AND TUESDAY AS ABOVE AVERAGE TEMPERATURES
BECOME MORE WIDESPREAD. HIGHS WILL TOP OUT IN THE 80S, POTENTIALLY
NEAR 90 FOR AREAS WITHIN THE CASCADE VALLEYS. WITH LOWS AROUND 60
FOR TUESDAY MORNING AROUND THE SEATTLE METRO, THERE IS THE
POTENTIAL FOR MODERATE HEATRISK FOR THOSE WHO ARE SENSITIVE TO
HEAT AND WITHOUT ADEQUATE COOLING/HYDRATION. GOING FORWARD, SOME
UNCERTAINTY EXISTS BY MID WEEK ON THE EXACT EVOLUTION OF THE MID-
LEVEL PATTERN. HOWEVER, TEMPERATURES ARE TRENDING COOLER IN THE
MOST RECENT MODELS RUNS AS A REPRIEVE FROM THE HEAT IS APPEARING
MORE FAVORABLE FOR WEDNESDAY AND THURSDAY.
MCMILLIAN
AVIATION
GENERALLY SOUTHERLY OR SOUTHEAST FLOW ALOFT THROUGH
THE AFTERNOON WITH THE UPPER TROUGH MOVING EASTWARD, BEFORE WESTERLY
FLOW ALOFT DEVELOPS TONIGHT. ONSHORE LOW-LEVEL FLOW WILL CONTINUE.
EXPECT VARIABLE HIGH CLOUDS THIS MORNING ACROSS WESTERN WASHINGTON.
LOOKING INTO THE AFTERNOON, WEAK CONVERGENCE ACROSS CENTRAL PUGET
SOUND COULD BRING SOME CEILINGS AROUND 5000 FT OR SO. WINDS WILL BE
GENERALLY LIGHT THIS MORNING, BUT INCREASE A BIT THIS AFTERNOON WITH
STRONGER ONSHORE FLOW INTO THE AFTERNOON AND EVENING. MVFR STRATUS
REMAINS ALONG THE COAST THIS MORNING, CLEARS THIS AFTERNOON, BUT
RETURNS 06-09Z TONIGHT. THIS STRATUS SPREADS INLAND INTO PUGET SOUND
TOWARD 12Z. FINALLY, SOME HAZE ACROSS THE METRO CORRIDORS IS
POSSIBLE LATE EVENING/EARLY TONIGHT AS STABILITY INCREASES.
KSEA...VARIABLE HIGH CLOUDS THIS MORNING, WITH SOME MID-LEVEL
CEILINGS AROUND 5000 FT EXPECTED INTO THE AFTERNOON AS WEAK
CONVERGENCES DEVELOPS. EXPECT LIGHT NORTHERLY WIND THIS MORNING
INCREASING TO AROUND 6 KT THIS AFTERNOON AS THEY BECOME MORE WEST AT
SEA. WILL NEED TO MONITOR WINDS AT BFI WITH LIKELY NORTH/NORTHWEST
WINDS CONTINUING AND REACHING 6-8 KT AS SEA BACKS AROUND TO
SOUTHWESTERLY. MVFR STRATUS REDEVELOPING AROUND 12Z.
MARINE
HIGH PRESSURE WILL REMAIN IN PLACE ACROSS THE COASTAL AND
OFFSHORE WATERS INTO THE FIRST PART OF NEXT WEEK WITH THERMALLY
INDUCED LOW PRESSURE EAST OF THE CASCADES. A WEAK FRONT WILL
APPROACH THE NORTHERN PORTION OF THE OFFSHORE WATERS TUESDAY.
DIURNAL WESTERLY PUSHES THROUGH THE STRAIT OF JUAN DE FUCA EACH
EVENING INTO EARLY NEXT WEEK. GALE FORCE WESTERLIES TONIGHT IN THE
CENTRAL AND EASTERN PORTION WITH SMALL CRAFT ADVISORY WINDS FOR
THE SAME AREA SATURDAY EVENING.
SMALL CRAFT ADVISORY NORTHWEST WINDS IN ADMIRALTY INLET TONIGHT
WITH THE GALE FORCE WINDS IN PORTIONS OF THE STRAIT OF JUAN DE
FUCA. FELTON
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...GALE WATCH FROM THIS AFTERNOON THROUGH LATE TONIGHT FOR CENTRAL
U.S. WATERS STRAIT OF JUAN DE FUCA-EAST ENTRANCE U.S.
WATERS STRAIT OF JUAN DE FUCA.
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