Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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FXUS66 KSEW 271043
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
345 AM PDT FRI MAR 27 2015

.SYNOPSIS...A FRONT WILL BRING RAIN TO THE COAST THIS AFTERNOON AND
TO THE INTERIOR THIS EVENING. A WEAK UPPER RIDGE WILL STEER WEATHER
SYSTEMS MOSTLY INTO BRITISH COLUMBIA OVER THE WEEKEND. A COLD FRONT
WILL REACH WESTERN WASHINGTON LATE MONDAY. A COOL SHOWERY UPPER
TROUGH WILL BE OVER THE AREA TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...AN UPPER RIDGE OVER EASTERN WASHINGTON THIS MORNING
WILL SHIFT INLAND TODAY AS A FRONT NEARS. RAIN SHOULD REACH THE
COAST THIS AFTERNOON...THEN SPREAD INTO THE INTERIOR THIS EVENING.
RAIN WILL CHANGE TO SHOWERS BEHIND THE FRONT LATER TONIGHT. SHOWERS
SHOULD BE MAINLY CONFINED TO THE CASCADES AND PERHAPS A PUGET SOUND
CONVERGENCE ZONE BY SATURDAY.

WESTERLY FLOW ALOFT WILL PREVAIL SATURDAY NIGHT AND SUNDAY. A PLUME
OF MOISTURE IN THE FLOW ALOFT WILL BE MAINLY AIMED AT VANCOUVER
ISLAND. THE NORTH COAST SHOULD HAVE RAIN AT TIMES DURING THIS PERIOD
WITH CHANCE POPS ELSEWHERE NEAR THE COAST AND NORTH INTERIOR. MAINLY
DRY WEATHER IS EXPECTED FURTHER SOUTH AND EAST. SCHNEIDER

.LONG TERM...A FRONT WILL REACH THE AREA LATE MONDAY OR MONDAY NIGHT
FOR A PERIOD OF RAIN. COOLER SHOWERY WEATHER WILL PREVAIL TUESDAY
AND WEDNESDAY WITH A BROAD UPPER TROUGH OVER THE PACIFIC NORTHWEST.
MODELS SUGGEST DRIER WEATHER IS POSSIBLE THURSDAY AS AN UPPER RIDGE
MOVES OVER THE REGION. SCHNEIDER

&&

.HYDROLOGY...FLOODING IS UNLIKELY THE NEXT 7 DAYS.

&&

.AVIATION...THE UPPER LEVEL RIDGE AXIS WILL CONTINUE TO SHIFT EAST
THIS MORNING WITH SOUTHWESTERLY FLOW ALOFT. GENERALLY DRY AND STABLE
CONDITIONS WITH LIGHT WINDS THIS MORNING. PATCHY LOW CLOUDS AND FOG
HAS BEGUN TO DEVELOP...MAINLY OVER THE SOUTH SOUND AND COAST. A COLD
FRONT WILL APPROACH THE AREA FROM THE WEST TODAY...MOVING ONTO THE
COAST DURING THE AFTERNOON AND INLAND THIS EVENING. INCREASING
SOUTHERLY FLOW AT LOW LEVELS THIS EVENING. RAIN WILL SPREAD INLAND
AFTER 00Z AND TRANSITION TO SHOWERS SATURDAY MORNING.

KSEA...VFR CONDITIONS TODAY WILL BECOME MVFR OVERNIGHT AS A FRONT
MOVES INTO THE INTERIOR. RAIN WILL REACH THE TERMINAL LATE IN THE
EVENING. LIGHT NE WINDS WILL BECOME SW 10 TO 12 KT IN THE AFTERNOON.

&&

.MARINE...WEAK HIGH PRESSURE AND LIGHT LIGHT WINDS OVER AREA WATERS
WILL GIVE WAY TO INCREASING SOUTHERLY FLOW AS A COLD FRONT
APPROACHES THE COASTAL WATERS THIS AFTERNOON. THE FRONT WILL MOVE
INSHORE LATE THIS AFTERNOON AND EVENING. EXPECT INCREASING SOUTHERLY
WINDS OVER THE COASTAL WATERS DURING THE AFTERNOON...AND THROUGH THE
INTERIOR THIS EVENING. ONSHORE FLOW VIA THE STRAIT WILL FOLLOW THE
FRONT LATER THIS EVENING THROUGH SATURDAY MORNING. SMALL CRAFT
ADVISORY WINDS ARE FORECAST FOR THE COASTAL WATERS DURING THE
AFTERNOON AND THE CENTRAL/EAST STRAIT OF JUAN DE FUCA...AND PUGET
SOUND AND HOOD CANAL TONIGHT INTO SATURDAY MORNING. HIGH PRESSURE
WILL REBUILD OVER THE REGION ON SATURDAY WITH A BREAK IN THE WINDS
OVER AREA WATERS. AN APPROACHING FRONTAL BOUNDARY WILL BRING
INCREASING SOUTHWESTERLY WINDS TO THE COASTAL WATERS SATURDAY NIGHT
AND SUNDAY.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT WEST ENTRANCE STRAIT OF
     JUAN DE FUCA.

&&

$$

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