930
FXUS66 KSEW 280401
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
800 PM PST TUE JAN 27 2026
UPDATE
BOTH SATELLITE AND RADAR SHOWING INCOMING FRONTAL SYSTEM
MOVING INTO THE AREA. ALTHOUGH THE LEADING EDGE LOOKS MORE
IMPRESSIVE ON RADAR, NOT MUCH IN THE WAY OF OBSERVED PRECIP WITH
THIS INITIAL BAND. OBSERVED PRECIP STILL GENERALLY WEST OF THE SOUND
AT THIS TIME, BUT WILL CONTINUE TO SPREAD EASTWARD OVERNIGHT.
INHERITED FORECAST LOOKS GOOD WITH REGARD TO PRECIP AMOUNTS
EMPHASIZING THE COAST AND MOUNTAINS WHILE AMOUNTS IN THE INTERIOR
LOWLANDS REMAIN GENERALLY LIGHT TONIGHT INTO WEDNESDAY MORNING.
SYNOPSIS
A FRONT, THE FIRST IN A SERIES OF SYSTEMS, IS APPROACHING THE
REGION THIS EVENING. EXPECT ADDITIONAL DISTURBANCES TO TRACK
ACROSS THE REGION OVER THE NEXT SEVERAL DAYS, EACH BRINGING AN
INCREASE IN PRECIPITATION COVERAGE AND GUSTY WINDS AS THEY
APPROACH AND CROSS THE AREA. HIGH PRESSURE IS EXPECTED TO
REBUILD OVER THE WEEKEND, WITH ANOTHER DISTURBANCE AROUND
SUNDAY. HIGH PRESSURE THEN IS LIKELY TO RETURN NEXT WEEK.
SHORT TERM /TODAY THROUGH THURSDAY NIGHT/
THE LEADING EDGE OF THE NEXT WEATHER SYSTEM IS CONTINUING TO
ADVANCE TOWARD THE COASTLINE THIS AFTERNOON, BRINGING AN
INCREASE IN GUSTY WINDS TO THE COAST ALONG WITH PRECIPITATION
OFFSHORE THAT IS EVIDENT ON RADAR. WE'LL SEE THIS PRECIPITATION
CONTINUE TO SPREAD INLAND TONIGHT THROUGH EARLY WEDNESDAY. WHILE
THE PRECIPITATION WILL INITIALLY BE IN THE FORM OF LIGHT SNOW
FOR MOST OF THE CASCADES, THERE'S A SMALL (10-20%) CHANCE OF
BRIEF FREEZING RAIN GIVEN THE SURFACE COOLER AIR; GIVEN THE
LIGHT PRECIPITATION AND MARGINAL PROFILE, THIS REMAINS A LOW
PROBABILITY SCENARIO.
PRECIPITATION WILL REMAIN MORE WIDESPREAD OVER THE NEXT FEW DAYS
AS ADDITIONAL DISTURBANCES REACH THE AREA. SNOW LEVELS WILL BE
RISING TO AROUND 4500 TO 5000 FT BY THURSDAY, BUT DEPENDING ON
WHERE THE PLUME OF MOISTURE AND WARMER AIR SETS UP, THIS COULD
VARY MORE SIGNIFICANTLY FROM NORTH TO SOUTH OVER THE WASHINGTON
CASCADES. THAT SAID, THE BULK OF THE PRECIPITATION WILL BE
FOCUSED ALONG THE OLYMPIC PENINSULA AND THIS IS WHERE THE FLOOD
POTENTIAL REMAINS THE HIGHEST - SEE THE HYDROLOGY SECTION FOR
ADDITIONAL DETAILS ON THIS CONCERN.
THIS ACTIVE WEATHER WILL ALSO RESULT IN GUSTY WINDS, MAINLY FOR
THE COAST AND THE AREAS FROM ISLAND COUNTY NORTHWARD. MEANWHILE,
WAVES NEAR THE PACIFIC COAST ARE EXPECTED TO APPROACH 18-20 FT
LATE WEDNESDAY INTO THURSDAY, BRINGING THE POTENTIAL FOR HIGH
SURF CONDITIONS.
LONG TERM /FRIDAY THROUGH TUESDAY/
ENSEMBLE SYSTEMS ARE IN LOCK-STEP REGARDING THE 500 MB PATTERN IN
THE LONG-TERM FORECAST. THEIR SOLUTIONS FAVOR GENERAL UPPER-LEVEL
RIDGING OVER THE WEST COAST AND UPPER-LEVEL TROUGHING OVER THE GULF
OF ALASKA AND NE PAC. THIS SET UP WILL ALLOW FOR MOIST SOUTHWESTERLY
FLOW OVER THE REGION AS A SERIES OF FRONTS ENTER W WA WITH THE FIRST
ARRIVING ON FRIDAY. DRIER WEATHER ON SATURDAY BARRING A FEW SHOWERS
BEFORE THE NEXT DISTURBANCE TAKES AIM ON SUNDAY AND SO FORTH.
REOCCURRING SPELLS OF WIDESPREAD RAIN AND POSSIBLE BREEZY WITH ARE
EXPECTED. SNOW LEVELS REMAINING ABOVE THE PASSES THROUGH THE PERIOD.
TEMPERATURES WILL REMAIN ABOVE AVERAGE AS WELL WITH HIGHS IN THE
LOWER TO MID 50S AND LOWS IN THE UPPER 30S TO MID 40S.
MCMILLIAN
AVIATION
A TROUGH WILL SWING A FRONTAL SYSTEM ACROSS THE
TERMINALS TONIGHT INTO WEDNESDAY, WITH SOUTHWEST FLOW ALOFT. FIRST
ROUND OF SHOWERS WILL MOVE THROUGH IN THE WARM SECTOR
TONIGHT/WEDNESDAY MORNING. BRIEF GUSTS UP TO 20 KT FROM THE
SOUTHEAST WILL CONTINUE THROUGH 05-06Z IN THE INTERIOR (FROM THE
CASCADES). VFR CEILINGS THIS EVENING WILL LOWER DOWN TO MVFR
WEDNESDAY MORNING (MAY TAKE LONGER TO LOWER IN THE INTERIOR INTO
EARLY AFTERNOON), AND REMAIN MVFR INTO THURSDAY. SOUTH WINDS WILL
PICK UP IN THE WARM SECTOR WEDNESDAY MORNING WITH SUSTAINED WINDS 10-
20 KT AND GUSTS TO 25-30 KT THROUGH THURSDAY MORNING. THE TRAILING
COLD FRONT WILL BRING ANOTHER ROUND OF LIGHT TO MODERATE RAIN
WEDNESDAY AFTERNOON INTO THURSDAY.
KSEA...VFR CONDITIONS THROUGH WEDNESDAY MORNING WITH MVFR BECOMING
LIKELY AFTER 18Z WEDNESDAY THROUGH THE REMAINDER OF THE TAF PERIOD.
RAIN EXPECTED OVER THE TERMINAL TONIGHT THROUGH WEDNESDAY MORNING,
AND AGAIN WEDNESDAY NIGHT THROUGH THURSDAY. IFR PROBABILITIES REMAIN
LESS THAN 10%, BUT CAN'T RULE OUT BRIEF VISIBILITY REDUCTIONS DOWN
TO 4 SM FROM RAIN. BREEZY SOUTHEAST WINDS AT 10 KT GUSTING TO 20 KT
WILL LINGER THROUGH 06Z. BRIEF BREAK IN THE GUSTS THROUGH 12Z WITH
WINDS PICKING BACK UP 10-15 KT GUSTING TO 25 KT REMAINDER OF
WEDNESDAY INTO THURSDAY.
HPR
MARINE
INCREASING SOUTHERLY WINDS OVER THE COASTAL WATERS THIS EVENING
AHEAD OF THE FRONTAL SYSTEM. THESE STRONGER WINDS WILL EXPAND
TO THE EASTERN STRAIT OF JUAN DE FUCA AS IT MOVES INLAND THIS
EVENING. SMALL CRAFT SOUTHEASTERLIES ARE ALSO EXPECTED ACROSS
THE REMAINING MARINE ZONES IMMEDIATELY WITH THE FRONT (EXCEPT
FOR THE CENTRAL STRAIT). SEAS ACROSS THE COASTAL WATERS WILL
BUILD AROUND AROUND 6 FT THIS AFTERNOON TO 10-14 FT OVERNIGHT.
ANOTHER SYSTEM WILL MOVE ACROSS THE AREA WATERS WEDNESDAY INTO
THURSDAY, WHICH LOOKS TO BRING ANOTHER ROUND OF GALES TO THE
COASTAL WATERS AND TO THE EASTERN STRAIT (AROUND A 60-70% CHANCE
OF GALES). IN ADDITION TO WINDS, SEAS WILL BUILD ACROSS THE
COASTAL WATERS TO 15-20 FT LATE WEDNESDAY INTO THURSDAY. THE
PATTERN WILL REMAIN ACTIVE OVER THE WEEKEND, WITH ADDITIONAL
SYSTEMS EXPECTED TO MOVE ACROSS THE AREA WATERS. SEAS WILL
GRADUALLY SUBSIDE ON FRIDAY, BUT LOOK TO REMAIN ELEVATED AND
RANGE BETWEEN 10-12 FT THROUGH THE WEEKEND.
HYDROLOGY
AFTER AN EXTENDED PERIOD WITHOUT APPRECIABLE, OR ANY, RAINFALL,
MULTIPLE ROUNDS OF RAIN WILL FALL OVER THE AREA THROUGH FRIDAY TO
ONCE AGAIN START JUICING UP AREA RIVERS. RAINFALL TOTALS WILL BE
MOST PRONOUNCED ON THE OLYMPIC PENINSULA. PRECIPITATION ON THE SOUTH
SLOPES OF THE OLYMPICS, ALONG WITH SNOW LEVELS RISING FROM 4000 FEET
UP TO 6000 FEET, WILL CAUSE THE SKOKOMISH RIVER TO BEGIN RISING OUT
OF ITS DOLDRUMS WEDNESDAY. THE RIVER COULD THEN REACH FLOOD STAGE AS
EARLY AS THURSDAY MORNING BUT MORE LIKELY LATER IN THE DAY. THE
RIVER WILL REMAIN ABOVE FLOOD STAGE INTO SATURDAY. NO RIVER FLOODING
EXPECTED ON THE REMAINDER OF THE RIVERS.
SEW WATCHES/WARNINGS/ADVISORIES
WA...FLOOD WATCH FROM 4 AM PST WEDNESDAY THROUGH LATE FRIDAY NIGHT
FOR FOOTHILLS OF THE WESTERN AND SOUTHERN OLYMPIC
PENINSULA-MIDDLE CHEHALIS RIVER VALLEY-OLYMPIA AND
SOUTHERN PUGET SOUND-OLYMPICS-SOUTHERN HOOD CANAL-WILLAPA
AND BLACK HILLS.
PZ...SMALL CRAFT ADVISORY UNTIL 4 PM PST WEDNESDAY FOR GRAYS HARBOR
BAR.
SMALL CRAFT ADVISORY UNTIL 6 AM PST WEDNESDAY FOR ADMIRALTY
INLET-NORTHERN INLAND WATERS INCLUDING THE SAN JUAN
ISLANDS-PUGET SOUND AND HOOD CANAL-WEST ENTRANCE U.S.
WATERS STRAIT OF JUAN DE FUCA.
GALE WARNING UNTIL 6 AM PST WEDNESDAY 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-EAST ENTRANCE U.S.
WATERS STRAIT OF JUAN DE FUCA.
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