Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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000
FXUS66 KSEW 281621
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
920 AM PDT SUN SEP 28 2014

.SYNOPSIS...WEAK HIGH PRESSURE ALOFT WILL BE OVER THE AREA TODAY. A
FRONT WILL BRING RAIN TO THE COAST MONDAY MORNING AND TO THE
INTERIOR OF WESTERN WASHINGTON BY THE AFTERNOON. SCATTERED SHOWERS
MONDAY NIGHT WILL LINGER INTO MIDWEEK. A STRONG UPPER RIDGE OF HIGH
PRESSURE IS LIKELY LATE IN THE WEEK.

&&

.SHORT TERM...LOW CLOUDS AND FOG ARE IN THE INTERIOR LOWLANDS OF WRN
WA. IT IS SUNNY IN THE MOUNTAINS AND ACROSS MOST OF THE COAST AND
MUCH OF THE STRAIT. THERE IS A BAND OF CIRRUS FROM SW WA ACROSS THE
CASCADES AND INTO NE WA. THE AREAS OF MORNING FOG AND LOW CLOUDS
WILL BURN OFF FOR THE AFTERNOON AND IT SHOULD BE A COUPLE DEGREES
WARMER FOR HIGHS TODAY. A FRONT WILL SPREAD RAIN TO THE COAST MONDAY
MORNING AND INTO THE INTERIOR FOR THE AFTERNOON. AN UPPER TROUGH AND
ONSHORE FLOW WILL GIVE SCATTERED SHOWERS MONDAY NIGHT AND
TUESDAY...THEN PETERING OUT TUE NIGHT AND WED AS HEIGHTS RISE A BIT.
ANOTHER SYSTEM MOVING INTO B.C. ON WED SHOULD NOT HAVE MUCH EFFECT
OVER WA. THE 500MB HEIGHT RISES TO AROUND 5700M...BUT IN WNW FLOW
ALOFT AND LOW LEVEL ONSHORE FLOW WE MAY SEE SOME PSCZ ACTIVITY AT
TIMES.

.LONG TERM...A FEW SHOWERS WILL LINGER WEDNESDAY WITH WNW FLOW
ALOFT. AN UPPER RIDGE WILL BUILD OVER THE PACIFIC NORTHWEST THURSDAY
FOR DRY WEATHER. THE RIDGE SHOULD REMAIN IN PLACE THROUGH SATURDAY.
MOISTURE FROM A WET SYSTEM MOVING INTO B.C. THU AND FRI COULD SAG
SOUTH AND BRUSH WRN WA SAT. MOST GFS ENSEMBLE MEMBERS HAVE BEEN DRY
AND WARMER FOR THE END OF THE WEEK. THE 00Z EURO WAS LESS OPTIMISTIC.

&&

.AVIATION...AN UPPER LEVEL LOW IS SPINNING OVER THE GREAT BASIN
TODAY...WHILE AN UPPER LEVEL RIDGE NUDGES EAST INTO WASHINGTON. THE
FLOW ALOFT IS WESTERLY. THE AIR MASS ACROSS WESTERN WA IS STABLE.
LOW CLOUDS AND FOG COVER THE INTERIOR LOWLANDS THIS MORNING WITH IFR
TO MVFR CONDITIONS. LOW CLOUDS WILL LIFT AND SCATTER THIS AFTERNOON
WITH VFR CONDITIONS EXPECTED. CLOUDS WILL INCREASE TONIGHT AS A COLD
FRONT APPROACHES. THIS FRONT WILL BRING RAIN TO THE AREA MON
MORNING. 33

KSEA...LOW CLOUDS WILL REMAIN IN THE AREA THROUGH 19-20Z...THEN
LIFT AND SCATTER WITH VFR CONDITIONS EXPECTED. LIGHT NORTH WINDS
WILL FLIP TO SOUTHERLY THIS EVENING BY 06Z. EXPECT INCREASING CLOUDS
OVERNIGHT WITH RAIN IN THE PUGET SOUND AREA MON MORNING. 33

&&

.MARINE...WEAK HIGH PRES WILL GIVE GENERALLY LIGHT WINDS ACROSS
WESTERN WA TODAY. A WEAK ONSHORE PUSH WILL BRING WESTERLY SMALL
CRAFT ADVISORY WINDS TO THE CENTRAL AND EAST STRAIT TONIGHT. A COLD
FRONT WILL CROSS WESTERN WA MON MORNING...WITH ONSHORE FLOW
INCREASING BEHIND THE FRONT MON AFTERNOON. WESTERLY GALES ARE
POSSIBLE THROUGH THE STRAIT LATE MON AFTERNOON AND EVENING. ONSHORE
FLOW WILL PREVAIL TUE AND WED...THEN WEAKEN ON THU AS HIGH PRES
SHIFTS INLAND. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY CENTRAL AND EAST STRAIT OF JUAN DE FUCA.

&&

$$

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