803
FXUS66 KSEW 202251
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
251 PM PST FRI DEC 20 2024
SYNOPSIS
A SERIES OF FRONTS WILL BRING SEVERAL ROUNDS OF LIGHT
PRECIPITATION INTO TOMORROW, WITH BREEZY WINDS AND SLIGHTLY
WARMER TEMPERATURES. A MORE ACTIVE PATTERN IS SET TO EVOLVE AND
TAKE SHAPE THIS WEEKEND AND LAST INTO NEXT WEEK, WITH AN INCREASED
CHANCE OF IMPACTFUL WEATHER ARRIVING DURING THE HOLIDAYS.
SHORT TERM /TONIGHT THROUGH MONDAY/
AN ACTIVE WEATHER PATTERN
CONTINUES ACROSS THE PAC NW AS A SERIES OF STORMS TRACK THROUGH
THE REGION. WE'RE SEEING SOME LIGHT WARM FRONTAL PRECIPITATION
ACROSS WESTERN WA TODAY AND THE TRAILING COLD FRONT WILL MOVE
INLAND TONIGHT. PRESSURE GRADIENTS WILL TIGHTEN ACROSS THE
CASCADES WITH GUSTY EAST WINDS EXPECTED BELOW THE GAPS (LIKE IN
NORTH BEND) - A WIND ADVISORY IS IN EFFECT THROUGH EARLY SATURDAY
MORNING.
WE'LL SEE A BRIEF BREAK IN THE WEATHER SATURDAY MORNING, THEN
MORE RAIN AND BREEZY WINDS SATURDAY AFTERNOON AND EVENING AS THE
NEXT SYSTEM ARRIVES. WINDS WILL BE STRONGEST OVER THE NORTH
COAST. SNOW LEVELS WILL BE LOWERING TO AROUND 4000 FT SATURDAY
NIGHT WITH AN INCH (OR TWO) OF NEW SNOW IN THE HIGHER CASCADE
PASSES LIKE STEVENS PASS AND WHITE PASS.
MORE WET WEATHER IS HEADED OUR WAY ON SUNDAY AND MONDAY, WITH
LITTLE BREAK IN THE ACTION. GUSTY E/SE WINDS ALSO EXPECTED ALONG
THE COAST. SNOW LEVELS HOVER AROUND 4000 FT IN THE CASCADES WITH
A FEW MORE INCHES OF SNOW OVER THE HIGHER PEAKS AND PASSES. 33
LONG TERM /TUESDAY THROUGH FRIDAY/
MORE ACTIVE WEATHER THROUGH
THE WEEK AHEAD AS STORM AFTER STORM BARRELS THROUGH THE PAC NW.
MAIN CONCERNS WILL BE ONGOING LOWLAND RAIN, BREEZY TO WINDY
CONDITIONS, AND POTENTIAL FOR HEAVY MOUNTAIN SNOW. TEMPERATURES
THROUGHOUT THE PERIOD WILL STAY ABOVE FREEZING WITH LOWS IN THE
40S AND HIGHS NEAR 50. THE AIR MASS WILL BE COOLER ON CHRISTMAS
DAY WITH SNOW LEVELS DOWN TO 3000 FT. SNOW IN THE MOUNTAINS MAY
IMPACT ALL CASCADE PASSES. 33
AVIATION
SOUTHWEST FLOW ALOFT TURNING MORE SOUTHERLY AS
AN UPPER TROUGH CONTINUES TO DIG OFFSHORE WITH A FRONT MOVING
ACROSS THE AREA. OFFSHORE FLOW IN THE LOWER LEVELS CONTINUING WITH
LIGHT E/SE WINDS. MOSTLY VFR ACROSS AREA TERMINALS THIS AFTERNOON
AS SCATTERED SHOWERS CONTINUE THROUGHOUT THE REGION, WITH BRIEF
MVFR CONDITIONS LIKELY WITHIN HEAVIER SHOWERS. FOG MAY DEVELOP IN
THE SOUTHWEST INTERIOR LOWERING CONDITIONS FOR MVFR/IFR, WITH
REMAINING AREAS LIKELY REBOUNDING TO VFR OVERNIGHT. WINDS WILL
START TO INCREASE BY SATURDAY AFTERNOON WITH ANOTHER FRONT
ARRIVING, WITH 10 TO 15 KNOTS WITH SE/S WINDS.
KSEA...VFR THIS AFTERNOON AS RAIN SHOWERS PERSIST AT THE TERMINAL.
AS SHOWERS PERSIST, COULD SEE A BRIEF DROP TO MVFR IF A HEAVIER
SHOWER PASSES OVER THE TERMINAL. E/SE WINDS 4 TO 8 KNOTS THROUGH
THE OVERNIGHT WILL START TO INCREASE AROUND 8 TO 12 KNOTS BY
LATE SATURDAY MORNING/AFTERNOON.
MAZURKIEWICZ
MARINE
A SERIES OF FRONTS WILL CROSS THE REGION OVER THE NEXT
SEVERAL DAYS, MAINTAINING SEAS ABOVE 10 FEET AND PERIODS OF BREEZY
CONDITIONS THROUGH THE WEEKEND AND INTO NEXT WEEK. A SMALL CRAFT
ADVISORY REMAINS IN EFFECT FOR THE COASTAL WATERS FOR INCREASED
SOUTHERLY WINDS AND ELEVATED SEAS. ANOTHER FRONT WILL MOVE THROUGH
THE COASTAL WATERS BY SATURDAY MORNING, PROMPTING THE UPGRADE FROM
THE GALE WATCH TO A GALE WARNING
COMBINED SEAS THIS AFTERNOON 9 TO 12 FEET. SEAS WILL THEN BEGIN TO
BUILD UPWARDS TO 15 TO 20 FEET ON SATURDAY AND REMAIN ELEVATED
THROUGH SUNDAY WITH LONG PERIOD SWELL. SEAS WILL ONCE AGAIN GROW
ON MONDAY AROUND 18 TO 22 FEET, AS THESE HIGH SEAS LOOK TO
MAINTAIN THROUGH THE MIDDLE OF NEXT WEEK.
MAZURKIEWICZ
HYDROLOGY
A SERIES OF DISTURBANCES ARE EXPECTED OVER THE
WEEKEND WITH ADDITIONAL ROUNDS OF PRECIPITATION. FLOODING IS NOT
LIKELY BUT MINOR RISES ON AREA RIVERS EXPECTED. THE SKOKOMISH RIVER
WILL CONTINUE TO RECEDE OUT OF MINOR FLOODING TONIGHT, BUT REMAIN IN
THE VICINITY OF FLOOD STAGE THE NEXT FEW DAYS. THE THREAT OF RIVER
FLOODING ACROSS WESTERN WASHINGTON WILL INCREASE AGAIN TOWARDS THE
MIDDLE OF NEXT WEEK AS ENSEMBLES CONTINUE TO INDICATE THE POTENTIAL
FOR SIGNIFICANT PRECIPITATION. WHILE DISCREPANCIES REMAIN, THIS MAY
LEAD TO AN INCREASED CHANCE RIVER FLOODING BECOMING MORE WIDESPREAD
AND LANDSLIDE CONCERNS THAT MAY IMPACT HOLIDAY TRAVEL.
MCMILLIAN
SEW WATCHES/WARNINGS/ADVISORIES
WA...WIND ADVISORY FROM 1 AM TO 7 AM PST SATURDAY FOR EAST PUGET
SOUND LOWLANDS.
PZ...SMALL CRAFT ADVISORY UNTIL 3 PM PST THIS AFTERNOON FOR WEST
ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY UNTIL 4 AM PST SATURDAY FOR COASTAL WATERS
FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-COASTAL WATERS
FROM JAMES ISLAND TO POINT GRENVILLE OUT 10 NM-COASTAL
WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER OUT 10 NM.
GALE WATCH FROM LATE TONIGHT THROUGH SATURDAY AFTERNOON 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.
GALE WARNING UNTIL 3 PM PST THIS AFTERNOON 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 POINT GRENVILLE TO CAPE SHOALWATER 10
TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 4 AM PST SATURDAY 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 POINT GRENVILLE TO CAPE SHOALWATER 10
TO 60 NM.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page