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000
FXUS66 KSEW 120436
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
936 PM PDT TUE JUN 11 2013

.SYNOPSIS...A LOW PRESSURE SYSTEM OVER VANCOUVER ISLAND WILL
REMAIN NEARLY STATIONARY THROUGH WEDNESDAY MORNING. THE UPPER
LOW WILL DRIFT SOUTH ALONG THE COAST WEDNESDAY AFTERNOON AND NIGHT
BEFORE MOVING OVER OREGON ON THURSDAY. THIS SYSTEM WILL BE EAST OF
THE AREA FRIDAY MORNING...WITH WEAK HIGH PRESSURE ALOFT FOLLOWING
IN ITS WAKE. UNSETTLED CONDITIONS WILL PREVAIL AND TEMPERATURES
WILL RUN NEAR OR LITTLE BELOW NORMAL.

&&

.SHORT TERM...
MUCH OF THE SHOWER ACTIVITY WAS CONFINED TO THE COAST AND THE
MOUNTAINS THIS EVENING AND THIS WILL LIKELY REMAIN THE CASE
OVERNIGHT.

MEANWHILE...AN UPPER LOW OVER CENTRAL VANCOUVER ISLAND WILL
REMAIN QUASI-STATIONARY THROUGH WED MORNING. DURING WED AFTERNOON
AND NIGHT...THE LOW WILL DRIFT SOUTH ALONG THE COAST. EXPECT THE
LOW TO MOVE INLAND OVER OREGON ON THU. BY FRI MORNING...THE LOW
PRESSURE SYSTEM WILL BE OVER THE NORTHERN GREAT BASIN. A WEAK
SHORT WAVE RIDGE WILL MOVE OVER THE AREA IN ITS WAKE. THE AIR MASS
WILL REMAIN SUFFICIENTLY UNSTABLE ON FRI THOUGH FOR A CONTINUED
RISK OF SHOWERS...ESPECIALLY OVER THE MOUNTAINS.

IT LOOKS LIKE THE BEST THREAT OF SHOWERS OVER THE INTERIOR WILL BE
ON WED. OTHERWISE...LOOK FOR UNSETTLED CONDITIONS TO PERSIST AND
TEMPS TO RUN NEAR OR LITTLE BELOW NORMAL FOR THIS TIME OF THE
YEAR.

.LONG TERM FROM THE PREV DISCUSSION...
MODELS WERE SHOWING RATHER GOOD CONSISTENCY THE FIRST HALF OF THE
WEEKEND. THEY ALL SHOWED A RIDGE THAT WILL BUILD OVER OR JUST TO
THE EAST OF THE AREA ON SATURDAY AS A NEW UPPER LOW DROPS INTO THE
WATERS AROUND 47N 134W. SATURDAY WILL LIKELY BE THE NICEST AND
WARMEST DAY OF THE UPCOMING WEEK ACROSS WESTERN WASHINGTON WITH
TEMPERATURES INTO THE 70S ACROSS MOST OF THE INTERIOR.

LATER SATURDAY NIGHT OR MORE LIKELY SUNDAY...SHOWER ACTIVITY WILL
BECOME MORE LIKELY...ESPECIALLY OVER THE CASCADES...AS FLOW ALOFT
BECOMES SOUTHERLY...MORE DIFFLUENT...AND THE AIR MASS ALOFT
BECOMES SOMEWHAT MORE UNSTABLE. EARLY NEXT WEEK THE NEXT UPPER LOW
OFFSHORE IS EXPECTED TO SLOWLY APPROACH THE AREA FROM THE WEST...
REACHING THE COASTLINE LATE TUESDAY OR WEDNESDAY. TEMPERATURES
WILL COOL AND SHOWERS WILL BECOME MORE LIKELY AS THE UPPER LOW
APPROACHES THEN PASSES ACROSS THE AREA. ALBRECHT

&&

.AVIATION...AN UPPER TROUGH WILL BE OVER THE REGION THROUGH
THURSDAY. SOUTHWEST FLOW ALOFT. LOW LEVEL ONSHORE FLOW. THE AIR MASS
IS MOIST AND A SOMEWHAT UNSTABLE.

CLOUDS WILL AT LEAST PARTIALLY FILL BACK IN TONIGHT WITH CONTINUED
ONSHORE FLOW. THE UNSTABLE AIR WILL PROBABLY KEEP LOW CLOUDS FROM
BECOMING TOO EXTENSIVE AS THE LOW LEVELS STAY RELATIVELY MIXED.
SCATTERED SHOWERS WILL CONTINUE.

KSEA...SOUTH WIND 8-12 KNOTS EASING A BIT TONIGHT. SCHNEIDER

&&

.MARINE...ONSHORE FLOW...SOUTHERLY FOR THE INLAND WATERS AND MORE
WESTERLY FOR THE COASTAL WATERS. LOW LEVEL FLOW WILL BECOME MORE
WESTERLY LATER THURSDAY WITH SMALL CRAFT ADVISORY WEST WINDS LIKELY
RETURNING TO THE CENTRAL AND EASTERN STRAIT OF JUAN DE FUCA.
SCHNEIDER

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...NONE.

&&

$$

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