Small Craft Advisory 149, NWS Seattle, WA

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SEATTLE WA
335 PM PDT TUE JUL 1 2014

.SYNOPSIS...THE UPPER LEVEL RIDGE OVER THE PACIFIC NORTHWEST
WILL CONTINUE TO SHIFT EAST TONIGHT. DEVELOPING ONSHORE FLOW TONIGHT
WILL RETURN MARINE STRATUS TO THE COAST AND SOUTH INTERIOR LATE
TONIGHT AND WEDNESDAY MORNING FOLLOWED BY AFTERNOON CLEARING.
STRONGER ONSHORE FLOW THURSDAY AND FRIDAY WILL BRING MORE WIDESPREAD
MORNING CLOUDS TO THE INTERIOR WITH AFTERNOON SUN. A WEAK FRONT WILL
AFFECT THE AREA THIS WEEKEND...BRINGING A CHANCE OF SHOWERS MAINLY
TO THE COAST AND MOUNTAINS.

&&

.SHORT TERM...AFTERNOON TEMPERATURES HAVE RISEN INTO THE UPPER 80S
TO LOWER 90S ACROSS WESTERN WASHINGTON...WITH SEVERAL LOCATIONS
MATCHING OR EVEN BREAKING RECORDS FOR THE DATE...INCLUDING
KSEA...KOLM...AND KBLI. THE THERMALLY INDUCED SURFACE TROUGH HAS
ALREADY SHIFTED INLAND THIS AFTERNOON WHICH WILL PUSH LOW LEVEL FLOW
TO BECOME ONSHORE LATE THIS EVENING. TONIGHTS ONSHORE FLOW WILL
REMAIN WEAK...LIMITING THE MARINE PUSH AND RESULTING STRATUS TO THE
STRAIT OF JUAN DE FUCA...CHEHALIS GAP...AND THE WEST EDGE OF PUGET
SOUND THROUGH WEDNESDAY MORNING.  HIGH TEMPERATURES WILL BE MUCH
COOLER THAN TODAY DESPITE AFTERNOON CLEARING AND SUNSHINE...DROPPING
INTO THE 60S FOR THE COAST AND 70S TO LOWER 80S OVER INLAND AREAS.
AS THE UPPER LEVEL RIDGE AXIS CONTINUES TO SHIFT EAST
TOMORROW...FLOW ALOFT WILL BECOME SOUTHERLY SETTING UP A PREFERRED
PATTERN FOR CONVECTION ALONG THE CREST OF THE CASCADES WHERE
ISOLATED HIGH BASED THUNDERSTORMS WILL BE POSSIBLE DURING THE
AFTERNOON AND EVENING HOURS.

ONSHORE FLOW WILL STRENGTHEN WEDNESDAY NIGHT PRODUCING A SOLID
MARINE PUSH AND MORE WIDESPREAD STRATUS OVER THE LOWLAND INTERIOR
BY THURSDAY MORNING. AN UPPER LEVEL LOW OVER THE NORTHEAST PACIFIC
WILL SWING A WEAK UPPER TROUGH OVER THE PACIFIC NORTHWEST ON
THURSDAY BRINGING INCREASED MID AND UPPER LEVEL CLOUDS AND SOME
MORNING DRIZZLE TO THE COAST AND WEST SLOPES OF THE OLYMPICS.
MORNING STRATUS WILL BURN OFF OVER THE INTERIOR TO A MOSTLY SUNNY
AFTERNOON AND NEAR NORMAL TEMPERATURES OVER THE LOWLANDS. LOW LEVEL
CLOUDS WILL REFORM AGAIN LATE THURSDAY NIGHT INTO FRIDAY MORNING.

.LONG TERM...THE UPPER LEVEL LOW OVER THE NORTHEAST PACIFIC WILL
RETROGRADE TO THE WEST FRIDAY AND OPEN INTO A BROAD UPPER TROUGH
OVER MUCH OF THE NORTHEAST PACIFIC AND GULF OF ALASKA. THIS WILL
HELP KEEP THE PATTERN A LITTLE MORE ACTIVE OVER THE AREA THROUGH THE
EXTENDED. MEDIUM RANGE MODELS HAVE BEEN HIGHLIGHTING A WEAK FRONTAL
SYSTEM MOVING THROUGH THE PACIFIC NORTHWEST ON SATURDAY AND SUNDAY
BRINGING SHOWERS AND LIGHT PRECIPITATION TO THE AREA AT TIMES. RUN
TO RUN AND MODEL TO MODEL CONSISTENCY HAS BEEN PRETTY VARIABLE OVER
THE LAST FEW CYCLES...WITH DIFFERENCES IN THE TIMING AND
DISTRIBUTION OF PRECIPITATION ESPECIALLY AHEAD OF THE FRONT FRIDAY
NIGHT AND SATURDAY. THE CURRENT FORECAST REFLECTS THE BEST CHANCE
FOR SHOWERS...MAINLY FOR THE COAST AND MOUNTAINS FRIDAY NIGHT AND
SATURDAY AND MORE WIDESPREAD SHOWERS SATURDAY NIGHT AND SUNDAY.

&&

.AVIATION...A STRONG UPPER LEVEL HIGH PRESSURE RIDGE WILL SHIFT EWD
TONIGHT AND WEDNESDAY. LIGHT SE FLOW ALOFT THIS EVENING...THEN LIGHT
TO MODERATE SW FLOW ALOFT. STABLE CONDITIONS. DRY CONDITIONS
TONIGHT...THEN INCREASING LOW LEVEL MOISTURE ON WEDNESDAY.

IFR STRATUS WILL LIKELY DEVELOP AT THE COAST TONIGHT AND PUSH
PARTIALLY INLAND THROUGH THE CHEHALIS GAP AND DOWN THE STRAIT OF
JUAN DE FUCA WEDNESDAY MORNING AS ONSHORE FLOW INCREASES. THIS WILL
PRIMARILY AFFECT KCLM...KHQM...KOLM...AND POSSIBLY KPAE.

KSEA...CLEAR CONDITIONS TODAY WITH VFR SKIES. LOW SCATTERED CLOUDS
MAY DEVELOP SUNDAY MORNING...BUT MARINE STRATUS IS NOT EXPECTED TO
REACH THE TERMINAL. NORTHERLY WIND 5-10 KNOTS...BECOMING LIGHT
TONIGHT AND THEN S-SWLY 5-10 KT AFTER 12Z SUNDAY. DTM

&&

.MARINE...A THERMAL LOW PRESSURE TROUGH OVER THE COASTAL WATERS WILL
SHIFT INLAND TONIGHT INDUCING ONSHORE FLOW. SMALL CRAFT ADVISORY
WESTERLY WINDS WILL DEVELOP OVER THE CENTRAL AND EASTERN STRAIT OF
JUAN DE FUCA AND ADJACENT INLAND WATERS WEDNESDAY...POSSIBLY
REACHING GALE IN THE STRAIT WEDNESDAY. FOR NOW...IT LOOKS LIKE THERE
COULD BE AN INITIAL SURGE OF GALES IN THE STRAIT WEDNESDAY
MORNING...FOLLOWED BY A MORE TYPICAL PERIOD OF GALES WEDNESDAY
AFTERNOON/WEDNESDAY EVENING AS ONSHORE FLOW PEAKS.

VARYING DEGREES OF ONSHORE FLOW WILL DOMINATE THE PATTERN THURSDAY
AND FRIDAY. SMALL CRAFT ADVISORY WEST WINDS ARE LIKELY EACH EVENING
FOR THE CENTRAL AND EASTERN STRAIT. A FRONT WILL REACH THE WATERS ON
SATURDAY. THIS SHOULD TURN WINDS SOUTHERLY MOST WATERS ON
SATURDAY.DTM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COAST.
    .GALE WATCH LATE TONIGHT THROUGH WEDNESDAY EVENING FOR THE
     CENTRAL AND EASTERN STRAIT OF JUAN DE FUCA.

&&

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