928
FXUS66 KSEW 301614
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
914 AM PDT MON JUN 30 2025
UPDATE
NO CHANGES TO THE OVERALL FORECAST. PLEASE SEE THE
AVIATION AND MARINE SECTIONS BELOW FOR UPDATES TO THOSE
FORECASTS.
SYNOPSIS
HIGH PRESSURE ALOFT WILL MAINTAIN WARM AND DRY
CONDITIONS ACROSS THE REGION EARLY THIS WEEK. AS THE HIGH
PRESSURE WEAKENS TOWARD MIDWEEK, EXPECT A RETURN TO NEAR NORMAL
TEMPERATURES. MOST AREAS REMAIN DRY THROUGH THE WEEK, THOUGH A
FEW SHOWERS ARE POSSIBLE NEAR THE COAST AND MOUNTAINS BY THE END
OF THE WEEKEND.
SHORT TERM /TODAY THROUGH WEDNESDAY/
HIGH PRESSURE REMAINS
IN PLACE OVER THE REGION THIS MORNING, SETTING THE STAGE FOR
ANOTHER WARM AND DRY DAY ACROSS WESTERN WASHINGTON. EXPECT
TEMPERATURES TO TREND A FEW DEGREES WARMER TODAY THAN YESTERDAY,
WITH WIDESPREAD 80S THIS AFTERNOON AND THE WARMEST SPOTS
APPROACHING OR REACHING THE 90 DEGREE MARK. THIS WILL MAINTAIN
AN AREA OF MODERATE (ORANGE) HEATRISK ACROSS THE INTERIOR FROM
CENTRAL PUGET SOUND SOUTHWARD, AS WELL AS IN THE FOOTHILLS AND
CASCADE VALLEYS. DEVELOPING ONSHORE FLOW TUESDAY WILL USHER IN A
COOLER DAY FOR THE COASTAL AREAS AND SPOTS WEST OF PUGET SOUND,
BUT NOT MUCH RELIEF FOR THE URBAN CORRIDOR FROM SEATTLE TO
TACOMA. SIMILARLY, WARMER CONDITIONS LINGER EASTWARD INTO THE
CASCADE VALLEYS WILL THE COOLING MARINE AIR WON'T SOLIDLY ARRIVE
UNTIL WEDNESDAY. THIS DEEPER MARINE PUSH WEDNESDAY WILL BRING
TEMPERATURE DOWN CLOSER TO NORMAL. WHILE PRECIPITATION ISN'T
EXPECTED, THERE SHOULD BE SOME ADDITIONAL CLOUDS IN THE MORNING
AND MIDDAY HOURS.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
CONFIDENCE IN THE
SPECIFICS OF THE PATTERN LATE IN THE WEEK, INCLUDING THE
INDEPENDENCE DAY HOLIDAY, REMAINS RATHER LOW WITH ENSEMBLE
GUIDANCE CONTINUING TO EXHIBIT A RATHER LARGE SPREAD IN HOW THE
PATTERN MAY EVOLVE. THE FORECAST CONTINUES TO REFLECT THE MOST
LIKELY SCENARIO OF A GENERALLY ZONAL FLOW PATTERN THAT WILL
PROVIDE FOR SOME MORNING CLOUDS AND TEMPERATURES CLOSE TO (OR
SLIGHTLY ABOVE) SEASONAL NORMALS. THIS WOULD LEAVE THE DOOR OPEN
TO PERHAPS A FEW LIGHT SHOWERS NEAR THE NORTHERN COAST AND IN
THE NORTH CASCADES OVER THE WEEKEND, BUT EVEN IN THESE FAVORED
LOCATIONS THE CHANCE OF RAIN REMAINS QUITE LOW (LESS THAN 20
PERCENT) FOR THE WEEKEND. 12
AVIATION
AN UPPER RIDGE AXIS WILL CONTINUE TO GRADUALLY SHIFT
EAST OF THE AREA TODAY WITH LIGHT WEST TO SOUTHWEST ALOFT. THE AIR
MASS REMAINS DRY AND STABLE WITH THE EXCEPTION OF A SHALLOW MARINE
LAYER ALONG THE IMMEDIATE COAST. VFR CONDITIONS WILL PREVAIL ACROSS
THE MAJORITY OF THE REGION TODAY. INCREASING LOW LEVEL ONSHORE FLOW
WILL BRING LIFR/IFR STRATUS INLAND THROUGH THE CHEHALIS GAP AND
STRAIT OF JUAN DE FUCA LATE TONIGHT, BUT IT IS UNLIKELY TO REACH
TERMINALS EAST OF PUGET SOUND ON TUESDAY MORNING.
KSEA...VFR. SURFACE WINDS NORTHEASTERLY 7 KNOTS OR LESS EARLY
BECOMING N/NW 8 TO 11 KNOTS THIS AFTERNOON.
27
MARINE
SURFACE RIDGING CENTERED OVER THE OFFSHORE WATERS AND
THERMALLY INDUCED LOW PRESSURE ACROSS THE INTERIOR OF WESTERN
WASHINGTON WILL LEAD TO CONTINUED GUSTY NORTHWEST WINDS AND CHOPPY
SEAS ACROSS THE COASTAL WATERS INTO TONIGHT. THE THERMAL TROUGH OVER
THE INTERIOR WILL GRADUALLY SHIFT EASTWARD TONIGHT RESULTING IN
PROGRESSIVELY STRONGER WESTERLY PUSHES IN THE STRAIT OF JUAN DE FUCA
LATER TODAY AND AGAIN ON TUESDAY. A DISSIPATING FRONT AND ASSOCIATED
UPPER TROUGH WILL SWING ACROSS THE WATERS LATE WEDNESDAY BEFORE WEAK
SURFACE RIDGING REBUILDS ACROSS THE WATERS LATE IN THE WEEK. 27
FIRE WEATHER
HIGH PRESSURE OVER THE REGION WILL MAINTAIN
WARM AND DRY CONDITIONS ACROSS THE REGION THROUGH MIDWEEK.
EXPECT DAYTIME RH VALUES TO DIP TO AROUND 30-35% ACROSS THE
CASCADES AND FROM CENTRAL PUGET SOUND SOUTHWARD. EXPECT ELEVATED
FIRE WEATHER CONDITIONS WITH A FEW SPOTS PERHAPS APPROACHING
25%. LIGHT NORTH OR NORTHEAST BREEZES INCREASE IN THE
AFTERNOONS. ONLY MODEST RH RECOVERIES TUESDAY MORNING IN THE
CASCADES UNDER THE INVERSION, THOUGH AREAS WEST OF PUGET SOUND
WILL SEE SOME INFLUENCE FROM A MARINE PUSH. A DEEPER MARINE PUSH
WEDNESDAY WILL BRING BETTER RECOVERIES AND COOLER TEMPERATURES
LATER IN THE WEEK. HOWEVER, OUTSIDE OF SOME 20% SHOWER CHANCES
IN THE NORTH CASCADES AND NEAR THE COAST OVER THE WEEKEND,
PRECIPITATION IS NOT EXPECTED THROUGH THE WEEK AHEAD.
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...{PHRASE}
GALE WATCH FROM TUESDAY AFTERNOON THROUGH LATE TUESDAY NIGHT
FOR CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA-EAST
ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY UNTIL 5 AM PDT TUESDAY FOR COASTAL WATERS
FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL
WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM-
COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE OUT
10 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE
SHOALWATER 10 TO 60 NM-COASTAL WATERS FROM POINT
GRENVILLE TO CAPE SHOALWATER OUT 10 NM.
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