Gale Warning 56, NWS Seattle, WA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
852 PM PDT TUE JUN 7 2011

.SYNOPSIS...AN UPPER LOW WILL MOVE THROUGH THE AREA TONIGHT...
BRINGING ISOLATED SHOWERS. SHOWERS WILL TAPER WEDNESDAY AS THE LOW
PULLS AWAY AND AN UPPER RIDGE BUILDS IN FROM THE WEST. A SECOND
UPPER TROUGH WILL BRING A CHANCE OF SHOWERS LATER THURSDAY AND
THURSDAY NIGHT. ONSHORE FLOW WILL PREVAIL FRIDAY THROUGH EARLY NEXT
WEEK FOR CONTINUED MOSTLY CLOUDY WEATHER.

&&

.SHORT TERM...SHOWERS ARE DECREASING ACROSS WESTERN WA THIS EVENING
AS AN UPPER LEVEL LOW SHIFTS EAST OF THE CASCADES. IN FACT...THERE
IS A BIT OF CLEARING IN THE INTERIOR BUT CLOUDS SHOULD FILL BACK IN
OVERNIGHT. THE LOW WILL MOVE OVER SE WA WED AFTERNOON...WITH MAINLY
DRY WEATHER ACROSS THE WEST SIDE. PRESSURE GRADIENTS WILL SLACKEN A
BIT AND WE SHOULD SEE PARTLY SUNNY SKIES...AT LEAST DURING THE
AFTERNOON.

AN UPPER LEVEL RIDGE WILL BRING A LITTLE MORE SUNSHINE AND SLIGHTLY
WARMER WEATHER ON THU. THIS RIDGE WILL QUICKLY DEPART BY FRI AS
ANOTHER TROUGH MOVES INLAND. SO EXPECT MORE CLOUDS AND A FEW SHOWERS
AS THIS NEXT SYSTEM PASSES BY. 33

.LONG TERM...LONG RANGE MODELS DIFFER WITH THE DETAILS BUT THE
GENERAL IDEA IS FOR WESTERLY FLOW ALOFT TO CONTINUE SATURDAY THROUGH
TUESDAY WITH VARYING AMOUNTS OF WEAK TROUGHING AND WEAK RIDGING. AT
THE LOW LEVELS...ONSHORE FLOW WILL CONTINUE. FOR NOW HAVE GONE WITH
A MOSTLY CLOUDY BUT ALSO MOSTLY DRY FORECAST. THE LATEST ECMWF DOES
BRING A FAIRLY WET SYSTEM THROUGH SUNDAY NIGHT AND MONDAY BUT THIS
IS A NEW WRINKLE AND AT ODDS WITH THE GFS AND...TO A LESSER
EXTENT...THE CANADIAN. SCHNEIDER

&&

.AVIATION...UPPER LEVEL LOW PRES OVER SOUTHEAST WASHINGTON MOVING
AWAY TO THE SOUTHEAST. STILL A FEW SHOWERS ASSOCIATED WITH THIS LOW
BUT THEY ARE MAINLY CONFINED TO THE CASCADES AND SOUTH. MODERATE
ONSHORE SURFACE FLOW. AIR MASS MOIST.

BIG CLEAR AREA OPENED UP OVER CENTRAL PUGET SOUND BUT MOST OTHER
AREAS REMAIN CLOUDY. THERE IS A GENERALLY SCATTERED DECK AROUND 3-4K
FT AND A BROKEN TO OVERCAST LAYER AROUND 8K FT. MOST TERMINALS WILL
PROBABLY SEE THE LOWER DECK BECOME A CEILING WHICH WILL LIKELY LOWER
TO MVFR OVERNIGHT. SOME CLEARING TOMORROW ESPECIALLY IN THE
AFTERNOON.

KSEA...DISCUSSION ABOVE APPLIES. WINDS LIKELY TO REMAIN SOUTHERLY
6-10 KT ALL NIGHT AND WEDNESDAY MORNING...THEN TRY TO TURN
NORTHWESTERLY IN THE AFTERNOON. CHB

&&

.MARINE...ONSHORE FLOW IS SLACKENING AS A WEAK LOW DEVELOPS ALONG
THE VANCOUVER ISLAND COAST. THE GALE WARNING IN THE STRAIT EXPIRED
EARLIER AND NOW THERE IS ONLY A SMALL CRAFT ADVISORY IN THE STRAIT
AND THE OUTER COASTAL WATERS. EVEN THESE ADVISORIES MAY LAPSE LATER
TONIGHT.

ONSHORE GRADIENTS RESUME WEDNESDAY AFTERNOON AND WILL PROBABLY BRING
AT LEAST SMALL CRAFT ADVISORY WESTERLIES TO THE STRAIT EACH
AFTERNOON AND EVENING THROUGH THE END OF THE WEEK. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY OUTER COAST AND CENTRAL AND EAST STRAIT.