604
FXUS66 KSEW 230859
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
159 AM PDT MON MAR 23 2026
SYNOPSIS.
WEAK HIGH PRESSURE WILL BRING DRY CONDITIONS TODAY.
ACTIVE WEATHER RETURNS ON TUESDAY FOR MORE RAIN, HIGH ELEVATION
SNOW AND GUSTY WINDS. SHOWERS AND A CONVERGENCE ZONE WILL FORM
ON WEDNESDAY WITH ONSHORE FLOW. DRIER WEATHER WILL PREVAIL LATE
IN THE WEEK AND INTO THE WEEKEND.
SHORT TERM /TODAY THROUGH WEDNESDAY/
WEAK HIGH PRESSURE IS OVER
THE AREA TODAY FOR DRY CONDITIONS. TEMPERATURES WILL BE MOSTLY
IN THE 30S THIS MORNING WITH FREEZING TEMPS AROUND THE SOUTH
SOUND. EXPECT HIGHS IN THE LOWER TO MID 50S THIS AFTERNOON (NEAR
NORMAL) WITH INCREASING CLOUDS DURING THE EVENING.
A STRONG AND WET PACIFIC FRONTAL SYSTEM WILL IMPACT THE AREA ON
TUESDAY. THIS SYSTEM IS TIED TO A DEEP LOW SPINNING OFFSHORE
THAT WILL SHIFT NORTH OF VANCOUVER ISLAND. THE MAIN THREAT WILL
BE GUSTY SOUTH WINDS, PRIMARILY COAST AND NORTH INTERIOR, WHERE
PROBABILITIES OF GUSTS EXCEEDING 45 MPH ARE THE HIGHEST. UP IN
THE MOUNTAINS, SNOW LEVELS ARE LOWEST OVER THE NORTHERN CASCADES
WHERE A FEW INCHES OF SNOW WILL FALL. SNOW LEVELS WILL BE
RISING OVER 6,000 FT IN THE CENTRAL CASCADES THUS MINIMIZING
IMPACTS TO I-90 AND US 2. RIVERS WILL SEE SMALL RISES BUT
ADDITIONAL FLOODING IS NOT ANTICIPATED.
WE REMAIN UNDER MODERATE ONSHORE FLOW ON WEDNESDAY WITH HIGH
PRESSURE OFFSHORE AND DEEP LOW PRESSURE TO OUR NORTH. SNOW
LEVELS ARE LOWER, AROUND 2,500 FT, WITH SNOW IN THE CASCADES AND
PASSES. SHOWERS WITH A CONVERGENCE ZONE MAY ENHANCE SNOW
AMOUNTS NEAR STEVENS PASS. THE AIR MASS IS SLIGHTLY UNSTABLE
WITH ISOLATED THUNDERSTORMS POSSIBLE TOO. 33
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
HIGH PRESSURE
SHIFTS INLAND ON THURSDAY WITH THE FLOW TURNING OFFSHORE. THIS
PATTERN WILL PERSIST THROUGH THE WEEKEND FOR SLIGHTLY WARMER AND
DRY WEATHER. HIGHS IN THE INTERIOR WILL REACH THE LOWER 60S
FRIDAY AND SATURDAY. A TROUGH KICKS THE RIDGE INLAND ON SUNDAY
WITH SLIGHTLY COOLER TEMPS AND A CHANCE OF RAIN. 33
AVIATION
ZONAL FLOW WILL CONTINUE TO PREVAIL ACROSS WESTERN
WASHINGTON TODAY. VFR CONDITIONS WILL PREVAIL FOR MUCH OF THE
TAF PERIOD WITH HIGH CLOUDS CONTINUOUSLY OVERHEAD. LOWER
CEILINGS WILL BEGIN TO REENTER THE FORECAST AFTER AROUND 06Z TUE
AS A WARM FRONT BEGINS TO ARRIVE ALONG THE COAST. THE BEST
CHANCES OF SEEING MVFR CIGS BY 12Z TUE WILL BE ALONG THE PACIFIC
COAST AND PORTIONS OF THE NORTH INTERIOR (INCL. BLI),
PROBABILITIES AROUND 25-50%. WINDS CALM TO LIGHT NORTHERLY THIS
MORNING, REMAINING NORTHERLY UP TO 4-8 KT THROUGH THE DAY.
KSEA...VFR CONDITIONS THROUGH THE PERIOD WITH HIGH CLOUDS OVERHEAD.
CEILINGS BEGIN TO REDEVELOP AND LOWER BUT REMAIN VFR AFTER 06-12Z
TUE. WINDS NORTH 6-10 KT THROUGH THE PERIOD.
62
MARINE
BROAD HIGH PRESSURE OVER THE REGION WILL MAINTAIN
RELATIVELY LIGHT WINDS AND SEAS IN THE 7 TO 9 FT RANGE TODAY. A
DEVELOPING LOW PRESSURE CURRENTLY IN THE NORTH-CENTRAL PACIFIC
AROUND 35 N/150 W WILL MOVE NORTHWESTWARD, REACHING THE AREA
EARLY TUESDAY. THE LOW CENTER WILL TRACK UP TOWARDS THE NORTHERN
POINT OF VANCOUVER, WITH THE ASSOCIATED COLD FRONT MOVING
ACROSS THE WASHINGTON COASTAL WATERS TUESDAY EVENING. WINDS WILL
START TO INCREASE ACROSS THE AREA EARLY TUESDAY MORNING. WINDS
PEAK FIRST ACROSS THE COASTAL WATERS TUESDAY AFTERNOON AHEAD OF
THE FRONTAL PASSAGE, THEN SUBSEQUENTLY THROUGH THE INTERIOR
WATERS LATER TUESDAY EVENING. GUIDANCE CONTINUES TO INDICATE
THAT GALE FORCE WINDS WILL BE LIKELY ACROSS THE COASTAL WATERS,
AS WELL AS THROUGH THE PUGET SOUND, ADMIRALTY INLET, AND INTO
THE EAST ENTRANCE TO THE STRAIT OF JUAN DE FUCA. ALL OF THESE
LOCATIONS CONTINUE TO BE UNDER A GALE WATCH THROUGH EARLY
WEDNESDAY MORNING. ELSEWHERE, WINDS WILL LIKELY MEET SMALL CRAFT
ADVISORY THRESHOLDS ON TUESDAY. WINDS WILL LIKELY REMAIN A BIT
ELEVATED FOR MUCH OF WEDNESDAY AS STRONG ONSHORE FLOW CONTINUES
BEHIND THE SYSTEM. CALMER CONDITIONS LOOK TO PREVAIL THURSDAY
THROUGH THE END OF THE WEEK AS HIGH PRESSURE LOOKS TO REDEVELOP
ACROSS THE AREA. IN ADDITION TO WINDS, SEAS WILL RISE ON
TUESDAY, PEAKING AROUND 15-18 FT, WITH SEAS UP TO AND EXCEEDING
20 FT POSSIBLE ACROSS THE NORTHWEST OUTER WATERS. GEFS GUIDANCE
CONTINUES TO SHOW A 40-60% CHANCE OF SEAS EXCEEDING 20 FT, WITH
THE HIGHEST CHANCES OVER THE OUTER NORTHWESTERN-MOST WATERS.
SEAS WILL SLOWLY SUBSIDE THROUGH THE DAY WEDNESDAY, BECOMING 6-8
FT THURSDAY THROUGH THE REST OF THE WEEK.
62
HYDROLOGY
FLOWS ON THE CEDAR RIVER AT RENTON REMAIN HIGH,
JUST BELOW MINOR FLOOD STAGE, DUE TO DAM OPERATIONS. OTHERWISE,
RIVERS WILL CONTINUE TO RECEDE TODAY. SMALL RISES ARE EXPECTED
WITH TUESDAY'S WETTER SYSTEM HOWEVER ADDITIONAL FLOODING IS NOT
EXPECTED. 33
SEW WATCHES/WARNINGS/ADVISORIES
WA...NONE.
PZ...GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY AFTERNOON FOR
ADMIRALTY INLET-EAST ENTRANCE U.S. WATERS STRAIT OF JUAN
DE FUCA.
GALE WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING FOR
PUGET SOUND AND HOOD CANAL.
GALE WATCH FROM LATE TONIGHT THROUGH TUESDAY EVENING FOR
COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND 10 TO
60 NM-COASTAL WATERS FROM CAPE FLATTERY TO JAMES ISLAND
OUT 10 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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