067
FXUS66 KSEW 211625
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
825 AM PST SAT DEC 21 2024
UPDATE
SATELLITE AND RADAR SHOW THE BAND OF PRECIPITATION
ASSOCIATED WITH THE OCCLUDED FRONT PASSING THROUGH THE AREA THIS
MORNING. OVERALL PRECIPITATION AMOUNTS HAVE BEEN LIGHT WITH THIS
FRONT AND WILL MOVE FAIRLY QUICKLY, SO NOT EXPECTED MUCH IN THE
WAY OF SIGNIFICANT HYDROLOGIC IMPACTS WITH THIS SYSTEM.
UNSTABLE AIR BEHIND THE FRONT MAY PROMOTE SOME ISOLATED
THUNDERSTORM ACTIVITY ALONG THE COAST, ESPECIALLY THIS AFTERNOON
WITH SOME DAYTIME HEATING AND COOLING ALOFT. TEMPERATURES THIS
MORNING ARE LARGELY IN THE MID 40S TO LOW 50S, WITH THE EXCEPTION
OF THE CASCADE FOOTHILLS, WHERE EASTERLY DOWNSLOPE WINDS HAVE KEPT
TEMPERATURES IN THE MID TO UPPER 50S. THE REST OF THE FORECAST IS
ON TRACK, WITH UPDATES TO THE AVIATION SECTION BELOW. 62
SYNOPSIS
ANOTHER FRONT ARRIVES TODAY FOR ADDITIONAL
PRECIPITATION AND BREEZY WINDS. A MORE ACTIVE PATTERN IS GOING TO
EVOLVE THIS WEEKEND AND LAST INTO NEXT WEEK, WITH AN INCREASED
CHANCE OF IMPACTFUL WEATHER ARRIVING DURING AND AFTER THE
HOLIDAYS.
SHORT TERM /TODAY THROUGH MONDAY/
THE NEXT FRONTAL SYSTEM WILL
BE ARRIVING THIS MORNING, FOR ELEVATED WINDS ALONG THE IMMEDIATE
COAST AND EAST PUGET SOUND LOWLAND LOCATIONS. A WIND ADVISORY HAS
BEEN ADDED FOR THE COAST TO ACCOUNT FOR STRONGER WINDS THIS
MORNING. WIND DIRECTION WILL BEGIN AS EASTERLY THIS MORNING,
TRANSITIONING TO SOUTHERLY BY EARLY AFTERNOON. RAIN AMOUNTS WON'T
BE PARTICULARLY IMPRESSIVE WITH THIS SYSTEM, WITH SHOWERS LARGELY
BECOMING SCATTERED BY THIS AFTERNOON. SNOW LEVELS WILL LOWER TO
AROUND 4000 FEET TONIGHT FOR A FEW INCHES OF SNOW AT STEVENS AND
WHITE PASS. THE NEXT FRONT ARRIVING ON SUNDAY HAS MORE IN THE WAY
OF QPF AND THE REGION CAN EXPECT MORE BREEZY SOUTHEASTERLY FLOW BY
SUNDAY AFTERNOON. SOME OF THE HIGH RES MODELS ARE SUGGESTIVE OF
SOME INSTABILITY AND POSSIBLE CONVECTION IN THE AREA OVER THE
WEEKEND, BUT FOR NOW, THE ALBEIT SLIGHT CHANCES WILL STILL BE
CONFINED TO THE COAST.
WITH MINIMAL REPRIEVE, ANOTHER SYSTEM ARRIVES ON MONDAY. FOR THE
LEAD TIME BETWEEN NOW AND MONDAY, THE MODELS ARE ALREADY CONFIDENT
ON WIDESPREAD AND GUSTY EASTERLY WINDS. SPEEDS AND TIMING COULD
CHANGE SOMEWHAT OVER THE WEEKEND, BUT IT DOES INCREASE CONFIDENCE
IN THE EVENT OVERALL. THE BULK OF MONDAY'S QPF SEEMS TO ARRIVE IN
THE AFTERNOON, LEADING TO A RAINY AND WINDY EVENING AND OVERNIGHT
PERIOD.
LONG TERM /TUESDAY THROUGH FRIDAY/
RAIN AND BREEZY WINDS WILL
LINGER INTO TUESDAY, WITH YET MORE STORMS POISED TO ARRIVE
THEREAFTER. THE MAIN IMPACTS POSSIBLE AT THIS STAGE WILL BE
ONGOING MODERATE TO POSSIBLY HEAVY RAIN, BREEZY TO WINDY
CONDITIONS, AND LOWERING SNOW LEVELS ON AND AFTER CHRISTMAS DAY TO
AROUND 3000 FEET CAUSING IMPACTFUL SNOW AT ALL CASCADE PASSES.
KRISTELL
AVIATION
RAIN SPREADING INLAND TODAY WITH S/SW FLOW ALOFT.
STRONG S WINDS ALONG THE COAST THE GUSTS TO 25 KT INLAND.
CEILINGS MAINLY VFR WITH POCKETS OF LOW-END VFR TO MVFR IN RAIN.
RAIN TAPERING OFF THIS EVENING WITH WINDS EASING AS WELL.
KSEA...RAIN THROUGH THE DAY. CEILINGS FAVORED TO LOWER TO NEAR
3000 FT BY THE AFTERNOON AND CONTINUING THROUGH THE EVENING.
SURFACE WINDS SOUTHERLY 8 TO 12 KT WITH GUSTS TO 25KT THROUGHOUT
THE AFTERNOON AND EVENING. WINDS EASING TO 4 TO 8 KT AND RETURNING
TO E/SE AFTER 6Z SUN.
33/15
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 EARLY NEXT WEEK. A SERIES OF
FRONTS MOVING OVER AREA WATERS THIS MORNING WILL GENERATE GALE FORCE
WINDS AND LARGE WAVES ACROSS THE OUTER WATERS TODAY WITH SMALL CRAFT
WINDS THROUGH THE NORTHERN SALISH SEA THROUGH THE ADMIRALTY INLET BY
THE AFTERNOON. WINDS WILL EASE OVERNIGHT, THOUGH SEAS WILL REMAIN
ELEVATED WITH AN SCA TO COVER.
ANOTHER SERIES OF FRONTAL SYSTEMS WILL CROSS THE REGION SUNDAY,
RESULTING IN ANOTHER SLEW OF GALE AND SMALL CRAFT HEADLINES THROUGH
AREA WATERS. ADDITIONAL HEADLINES ARE LIKELY HEADING INTO NEXT WEEK
AS ANOTHER ROUND OF WINDY CONDITIONS AND ELEVATED SEAS ARE EXPECTED
MONDAY, AND POTENTIALLY AGAIN ON WEDNESDAY.
COMBINED SEAS 10 TO 14 FEET WILL BUILD UPWARDS OF 15 TO 20 FEET BY
THE AFTERNOON TODAY, WHERE SEAS WILL REMAIN ELEVATED THROUGH SUNDAY
WITH LONG PERIOD SWELL. SEAS WILL REMAIN ELEVATED ABOVE 12 FEET
THROUGH THE PERIOD, WITH ANOTHER ROUND OF SEAS BUILDING TO 18 TO 22
FEET ON MONDAY AND AGAIN TOWARDS THE MIDDLE OF THE WEEK.
15
HYDROLOGY
A SERIES OF DISTURBANCES 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 SLOWLY DROPPING JUST BELOW FLOOD STAGE
OVERNIGHT THEN REMAIN NEAR FLOOD STAGE THROUGH THE WEEKEND INTO
NEXT WEEK. INCREASING PRECIPITATION AROUND CHRISTMAS COULD PUSH
THE SKOKOMISH BACK UP TO MODERATE FLOOD STAGE. FOR THE REMAINING
RIVERS, THE THREAT OF FLOODING WILL ALSO INCREASE IN THE MIDDLE
OF NEXT WEEK AS ENSEMBLES CONTINUE TO INDICATE THE POTENTIAL FOR
SIGNIFICANT PRECIPITATION. WHILE DISCREPANCIES REMAIN, THIS MOST
LIKELY WILL LEAD TO AN INCREASED CHANCE OF RIVER FLOODING BECOMING
MORE WIDESPREAD AND LANDSLIDE CONCERNS THAT MAY IMPACT HOLIDAY
TRAVEL.
MCMILLIAN/FELTON
SEW WATCHES/WARNINGS/ADVISORIES
WA...WIND ADVISORY UNTIL 2 PM PST THIS AFTERNOON FOR CENTRAL COAST-
NORTH COAST.
PZ...SMALL CRAFT ADVISORY UNTIL 6 PM PST SUNDAY FOR GRAYS HARBOR BAR-
WEST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR ADMIRALTY
INLET-EAST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA-
NORTHERN INLAND WATERS INCLUDING THE SAN JUAN ISLANDS.
GALE WATCH FROM LATE TONIGHT THROUGH SUNDAY AFTERNOON FOR EAST
ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.
SMALL CRAFT ADVISORY FROM 2 AM TO 6 PM PST SUNDAY FOR ADMIRALTY
INLET-NORTHERN INLAND WATERS INCLUDING THE SAN JUAN ISLANDS.
SMALL CRAFT ADVISORY UNTIL 10 PM PST THIS EVENING FOR PUGET
SOUND AND HOOD CANAL.
GALE WARNING UNTIL 4 PM PST THIS 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.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 4 AM PST SUNDAY
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 WATCH FROM LATE TONIGHT THROUGH SUNDAY 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.
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