848
FXUS66 KSEW 180353
AFDSEW
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
753 PM PST TUE FEB 17 2026
SYNOPSIS
A BROAD LOW PRESSURE SYSTEM OVER THE NE PACIFIC WILL MOVE
SOUTHEASTWARD THROUGH THURSDAY, KEEPING SCATTERED RAIN AND
OVERNIGHT SNOW SHOWERS IN THE FORECAST THROUGH THEN. COOLER
TEMPERATURES FOLLOW THURSDAY AND FRIDAY WITH FRASER RIVER
OUTFLOW. A WARMER PATTERN RETURNS FRIDAY INTO EARLY NEXT WEEK,
ACCOMPANIED BY A MORE SIGNIFICANT SYSTEM BRINGING GUSTY WINDS,
AS WELL AS ADDITIONAL RAIN AND MOUNTAIN SNOW.
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/
SCATTERED SHOWERS PERSIST, MAINLY MOVING NORTH THROUGH KING
COUNTY AND THE ADJACENT CASCADE FOOTHILLS. PRECIPITATION IS
LARGELY RAIN, BUT SOME SNOWFLAKES COULD MIX IN BEFORE THINGS
WIND DOWN A BIT OVERNIGHT. NO OTHER MAJOR CHANGES HAVE BEEN MADE
TO THE FORECAST SO THE PREVIOUS ONE CAN BE FOUND BELOW, WITH AN
UPDATE TO THE AVIATION SECTIONS.
THESE ONGOING SHOWERS ARE BEING SUPPORTED BY A VERTICALLY-
STACKED LOW PRESSURE SYSTEM CURRENTLY CENTERED OVER THE OFFSHORE
WATERS OFF WASHINGTON. THIS LOW/TROUGH WILL MOVE TO THE
SOUTHEAST TONIGHT INTO WEDNESDAY, WHICH WILL ALLOW FOR AN
INCREASE IN SHOWER COVERAGE ONCE AGAIN LATE TONIGHT AND THROUGH
MUCH OF THE DAY WEDNESDAY. TEMPERATURES WILL BE COLD ENOUGH TO
SUPPORT SOME SNOW SHOWERS ACROSS MOST OF THE AREA THROUGH AROUND
9/10 AM WEDNESDAY, IN PARTICULAR ACROSS THE OLYMPIC PENINSULA.
SPECIFIC AMOUNTS AND LOCATIONS ARE DIFFICULT TO DEFINE DUE TO
THE SHOWERY NATURE OF THE PRECIPITATION, BUT MOST ALL LOCATIONS
SHOULD RECEIVE LESS THAN ONE INCH OF ACCUMULATING SNOWFALL BASED
ON THE AMOUNT OF QPF IN THE FORECAST AND THE FACT THAT
TEMPERATURES WILL ALLOW FOR MELTING WEDNESDAY AFTERNOON.
AS THE SYSTEM CONTINUES TO DEPART TO THE SOUTHEAST, PRECIPITATION
WILL BEGIN TO CEASE ACROSS MUCH OF THE AREA BY WEDNESDAY EVENING.
THURSDAY LOOKS TO REMAIN MOSTLY DRY ACROSS THE AREA, WITH BEST
CHANCES FOR CONTINUED LIGHT PRECIPITATION ACROSS THE SOUTH, MAINLY
SOUTH OF OLYMPIA.
LOW TEMPERATURES WEDNESDAY MORNING WILL BE SIMILAR TO TODAY--IN THE
LOW 30S TO UPPER 20S, MAINLY ACROSS THE OLYMPIC PENINSULA AND AWAY
FROM THE SEATTLE METRO. FRASER RIVER OUTFLOW WINDS WILL BEGIN TO
INCREASE TONIGHT, BUT LIMITED TO WESTERN WHATCOM COUNTY, WHERE WIND
CHILLS WILL BEGIN TO DROP TO AROUND 20 DEGREES. HIGH TEMPERATURES
ACROSS THE AREA WILL REMAIN SIMILAR THROUGH WEDNESDAY AND THURSDAY,
IN THE LOW 40S, EXCEPT ACROSS THE NORTHWEST INTERIOR INTO THE STRAIT
OF JUAN DE FUCA WHERE FRASER OUTFLOW WILL HELP KEEP HIGHS DOWN INTO
THE MID TO UPPER 30S. LOW TEMPERATURES WILL BE COOLER AREA-WIDE
THURSDAY MORNING, WITH MOST AREAS IN THE MID TO UPPER 20S. LOWER 20S
ARE POSSIBLE IN WESTERN WHATCOM COUNTY WITH CONTINUED WINDY
CONDITIONS PUSHING WIND CHILLS INTO THE TEENS. FRASER OUTFLOW WINDS
WILL BEGIN TO EASE THURSDAY EVENING.
LONG TERM /FRIDAY THROUGH TUESDAY/
FRIDAY WILL MARK THE START OF A WARMING TREND AS THE COLD TROUGH
GETS PUSHED OUT BY A WEAK UPPER LEVEL RIDGE THAT WILL BEGIN TO BUILD
OVER THE INTERMOUNTAIN WEST OVER THE WEEKEND. ADDITIONALLY, A LARGE
UPPER TROUGH WILL DIG OVER THE NE PACIFIC OUT OF THE GULF OF ALASKA,
WHICH WILL HAVE SEVERAL SHORTWAVES ROTATING THROUGH IT TO THE
NORTHEAST. THIS TROUGH LOOKS TO DEVELOP SEVERAL STRONGER, BUT FAST-
MOVING, LOW PRESSURE SYSTEMS JUST OFFSHORE THIS WEEKEND AND INTO
EARLY NEXT WEEK. THESE SYSTEMS WILL PUSH SNOW LEVELS UP TO AROUND
2000-3000 FT. WHILE QPF AND SNOW AMOUNTS DON'T LOOK TO BE NOTEWORTHY
AT THIS POINT, THESE WILL BE WINDIER SYSTEMS WITH MORE WIDESPREAD
BREEZY TO GUSTY CONDITIONS. A FEW INCHES OF SNOW WILL BE POSSIBLE AT
THE PASSES WILL BE POSSIBLE EACH DAY. TEMPERATURES WILL WARM WITH
HIGHS GOING UP INTO THE MID TO UPPER 40S FRIDAY AND SATURDAY,
REACHING THE LOW 50S SUNDAY AND ONWARD. LOWS RETURN TO THE MID TO
UPPER 30S. IN OTHER WORDS, RIGHT AROUND CLIMATOLOGY FOR THIS TIME OF
YEAR.
62
AVIATION
SOUTHWEST FLOW ALOFT TONIGHT WILL MAINTAIN SCATTERED SHOWERS
ACROSS THE AREA, THOUGH COVERAGE IS LIMITED. EXPECT PREDOMINANTLY
VFR CEILINGS TO CONTINUE TONIGHT THOUGH ADDITIONAL SHOWER
ACTIVITY WILL ROTATE THROUGH THE REGION OVERNIGHT AND LOOKS TO
SUPPORT ANOTHER ROUND OF LOWERING CEILINGS AND MIXED MVFR/IFR
CONDITIONS IN HEAVIER SHOWERS. WITH TEMPERATURES COOLING OVERNIGHT,
THESE SHOWERS COULD BE MIXED OR EVEN ENTIRELY SNOW. WHILE SNOW
ACCUMULATIONS AT THE TERMINALS REMAIN UNLIKELY, A HEAVY SHOWER
COULD BRING A QUICK ACCUMULATION DOWN TO THE SURFACE. SHOWER
ACTIVITY WILL CONTINUE THROUGH THE DAY WEDNESDAY, THOUGH EXPECT
A RETURN TO PRIMARILY VFR CEILINGS BY THE AFTERNOON HOURS. WINDS
WILL REMAIN GENERALLY LIGHT AND VARIABLE FOR MOST TERMINALS,
THROUGH WILL BE OFFSHORE WINDS AT KBLI.
KSEA...SHOWERS MOVING INTO THE TERMINAL TONIGHT HAVE BROUGHT
RAIN AND CONDITIONS BACK DOWN TO MVFR THIS EVENING. GENERALLY
EXPECT CEILINGS TO HOVER BETWEEN MVFR AND VFR TONIGHT, BEFORE
MORE PROLONGED MVFR CONDITIONS TAKE HOLD OF THE TERMINAL BY
EARLY WEDNESDAY. TEMPERATURES COOLING TONIGHT WILL ALLOW SOME
POTENTIAL FOR SHOWERS TO BECOME SNOW IF THEY GET HEAVY ENOUGH
GENERALLY BETWEEN 10Z-15Z. LITTLE TO NO SNOW ACCUMULATION IS
EXPECTED AT THIS TIME, THOUGH SHOULD SHOWERS BECOME HEAVY ENOUGH,
BRIEF ACCUMULATIONS MAY OCCUR. WINDS WILL REMAIN GENERALLY LIGHT
AND OUT OF THE SOUTH TONIGHT INTO WEDNESDAY.
14
MARINE
LOW PRESSURE WILL REMAIN OFFSHORE OVER THE NEXT FEW DAYS. AS
THIS PUSHES INLAND, WINDS WILL SHIFT DIRECTION BUT SPEEDS WILL
REMAIN WELL BELOW ADVISORY THRESHOLDS. LATEST OBSERVATIONS SHOW
SEAS HOVERING BETWEEN 10-15 FT OVER THE COASTAL WATERS TONIGHT
AND BETWEEN 9-11 FT ACROSS THE WESTERN ENTRANCE OF THE STRAIT-
WHERE SMALL CRAFT ADVISORIES REMAIN IN EFFECT THROUGH EARLY
WEDNESDAY MORNING, WHEN SEAS ARE EXPECTED TO GRADUALLY SUBSIDE
AGAIN.
FRASER OUTFLOW WILL INCREASE ON THURSDAY MORNING ACROSS THE
NORTHERN INLAND WATERS, WHERE SOME OCCASIONAL WIND GUSTS TO
20-25 KT ARE POSSIBLE. OTHERWISE, THE ATTENTION TURNS TO THE
NEXT FRONTAL SYSTEM LATE IN THE WEEK WITH INCREASING WINDS OVER
THE WATERS AND THE RETURN OF SEAS INTO THE 15-17 FT RANGE BY
LATE IN THE WEEKEND.
14
HYDROLOGY
NO RIVER FLOODING IS EXPECTED IN THE NEXT SEVEN DAYS.
SEW WATCHES/WARNINGS/ADVISORIES
WA...COLD WEATHER ADVISORY FROM 1 AM TO 10 AM PST WEDNESDAY FOR
LOWLANDS OF WESTERN WHATCOM COUNTY.
PZ...SMALL CRAFT ADVISORY UNTIL 4 AM PST WEDNESDAY FOR GRAYS HARBOR
BAR.
SMALL CRAFT ADVISORY UNTIL 8 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-WEST ENTRANCE U.S.
WATERS STRAIT OF JUAN DE FUCA.
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