403
FXUS66 KSEW 300338
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
838 PM PDT SUN JUN 29 2025
SYNOPSIS
RIDGING OVER THE WESTERN US WILL KEEP THE START OF
THE WEEK WARM AND DRY. TEMPERATURES WILL TREND COOLER MIDWEEK
INTO THE HOLIDAY WEEKEND, NEAR OR A BIT WARMER THAN NORMAL.
CONDITIONS ALSO LOOK TO REMAIN GENERALLY DRY FOR MOST AREAS
OTHER THAN THE PERIODS OF LIGHT RAIN ALONG THE NORTH COAST
SATURDAY AND NORTH CASCADES SUNDAY.
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/
OVERALL IT IS SHAPING
UP TO BE A RATHER NICE EVENING ACROSS WESTERN WASHINGTON. SATELLITE
IMAGERY SHOWS CLEAR SKIES ACROSS THE INTERIOR WITH SOME STRATUS
LOCATED JUST OFF THE COAST. HAVE ONLY MADE MINOR TWEAKS TO THE
FORECAST TONIGHT TO ACCOUNT FOR THE EXTENT OF THE CLOUD COVER
ALONG THE COAST AND ACROSS THE COASTAL WATERS. OTHERWISE, THE
FORECAST REMAINS LARGELY ON TRACK. THE REMAINDER OF THE PREVIOUS
DISCUSSION FOLLOWS BELOW, WITH UPDATES MADE TO THE AVIATION
SECTION. 14
WITH THE RIDGE AXIS OVERHEAD AND LIGHT LOW LEVEL OFFSHORE FLOW
MONDAY CONTINUES TO LOOK TO BE THE WARMEST DAY OF THE STRETCH FOR
MANY AREAS. THIS WILL BRING TEMPERATURES INTO THE MID TO UPPER 80S
WITH A FEW SPOTS EXPECTED TO REACH THE 90 DEGREE MARK. THIS WILL
RESULT IN A CORRIDOR OF MODERATE (ORANGE) HEATRISK FOR THE
INTERIOR FROM THE CENTRAL PUGET SOUND SOUTHWARD AND AND SOME OF
THE FOOTHILLS AND CASCADE VALLEYS.
DEVELOPING ONSHORE FLOW TUESDAY WILL RESULT IN A COOLDOWN FOR
AREAS WEST OF PUGET SOUND, LEAVING ANOTHER WARM DAY FOR THE
URBAN CORRIDOR FROM SEATTLE TO TACOMA AS WELL AS IN THE CASCADES
FOOTHILLS AND VALLEYS. THIS WILL YIELD A SECOND MODERATE
HEATRISK DAY FOR THESE AREAS ON TUESDAY.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
A MORE FULLY DEVELOPED
ONSHORE PUSH WILL RETURN WEDNESDAY BRINGING A RETURN OR MORNING
CLOUDS AND TEMPERATURES CLOSER TO SEASONAL NORMALS WEDNESDAY
AND THURSDAY. THE MOST LIKELY FORECAST REMAINS GENERALLY DRY
THROUGH THE PERIOD FOR MOST AREAS. THE ZONAL PATTERN DOES LEAVE
THE DOOR OPEN FOR THE POTENTIAL FOR THE ODD WEAK SHORTWAVE
TROUGH TO BRUSH THE REGION. THE NBM HAS BACKED OFF THE POTENTIAL
FOR SHOWERS INTO SATURDAY AND SUNDAY - MOSTLY ALONG THE NORTH
COAST AND NORTH CASCADES, WITH MOST LOCATIONS REMAINING OTHERWISE
DRY.
AVIATION
HIGH PRESSURE OVER THE REGION FOR DRY AND STABLE
CONDITIONS. LOW LEVEL STRATUS CLOUDS WILL IMPACT THE COAST TONIGHT
AND MONDAY MORNING WITH VFR CONDITIONS ELSEWHERE. N WINDS IN THE
INTERIOR, GUSTING TO 20 KT THIS EVENING, OTHERWISE SUSTAINED WINDS
RUNNING 5-10 KTS ARE EXPECTED.
KSEA...VFR WITH N WINDS GUSTING TO 20 KT THIS EVENING BEFORE EASING
TONIGHT TO SUSTAINED WINDS RUNNING 5-10 KTS. 33/18
MARINE
A THERMAL TROUGH ALONG THE COAST WILL LEAD TO STRONG NW
WINDS OVER THE COASTAL WATERS - A SMALL CRAFT ADVISORY REMAINS IN
EFFECT INTO MONDAY MORNING. ONSHORE FLOW WILL INCREASE MONDAY AND
TUESDAY AS THE THERMAL TROUGH MOVES INLAND. GALES ARE LIKELY THROUGH
THE STRAIT OF JUAN DE FUCA TUESDAY NIGHT. A WEAK FRONT WILL CROSS
THE WATERS ON WEDNESDAY. 33
FIRE WEATHER
WARM AND DRY CONDITIONS ARE EXPECTED TO PERSIST
THROUGH TUESDAY AS HIGH PRESSURE REMAINS OVERHEAD. WITH THESE
TEMPERATURES, RELATIVE HUMIDITY VALUES DURING THE DAY MONDAY WILL
BE AS LOW AS 25% IN SOME OF THE SOUTHERN CASCADE VALLEYS (PORTIONS
OF ZONES 658 AND 659), WITH REMAINING CASCADE AND PUGET
SOUND/SOUTH INTERIOR AREAS SEEING RH'S AS LOW AS 30-40%. THIS WILL
ELEVATE FIRE WEATHER CONCERNS DUE TO THE DRY CONDITIONS THROUGH
TUESDAY, AS RH'S IN SOME OF THESE AREAS MAY NOT FULLY RECOVER. THE
PATTERN TRENDS COOLER BY WEDNESDAY, WHICH WILL IMPROVE RH'S
ACROSS WESTERN WA AND WILL LESSEN FIRE CONCERNS. WINDS ARE
EXPECTED TO REMAIN LIGHT THROUGH THE WEEK, WITH LIGHT NORTH TO
NORTHEAST AND VARIABLE WINDS.
HPR
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 5 AM PDT MONDAY 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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