Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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000
FXUS66 KSEW 191728
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 AM PST WED NOV 19 2014

.SYNOPSIS...A FRONT WILL BRING A LITTLE RAIN TONIGHT. A STRONGER
WEATHER SYSTEM WILL BRING RAIN AND WIND ON FRIDAY. ADDITIONAL
WEATHER SYSTEMS WILL ARRIVE EVERY DAY OR TWO INTO THE FIRST PART OF
NEXT WEEK KEEPING THE WEATHER WET AT TIMES.

&&

.SHORT TERM...A FEW ISOLATED SPRINKLES ON THE RADAR THIS MORNING
WILL MOVE NORTH THROUGH WESTERN WASHINGTON TODAY ACCORDING TO THE
HRRR MODEL. AS A SHORTWAVE TROUGH AND ITS ASSOCIATED FRONTAL SYSTEM
WILL APPROACH THE AREA TONIGHT...BRINGING SOME RAIN AND LIKELY A FEW
INCHES OF SNOW TO THE HIGHER ELEVATION PASSES AND SKI AREAS. WITH
LOWER SURFACE PRESSURE TO THE WEST AND HIGHER PRESSURE TO THE
EAST...EASTERLY WINDS MOVING THROUGH THE PASSES AT THE LOWER LEVELS
WILL CREATE A CHANCE FOR FREEZING RAIN THERE TONIGHT AND INTO EARLY
THURSDAY MORNING.

RAIN WILL DECREASE IN COVERAGE THURSDAY AND THURSDAY NIGHT AS THE
UPPER TROUGH MOVES OFF TO THE NORTHEAST AND A WEAK SURFACE LOW MOVES
INTO NORTHERN CALIFORNIA. THURSDAY NIGHT WILL LIKELY BE DRY ACROSS
MOST OF THE AREA.

ON FRIDAY AND FRIDAY NIGHT...A STRONGER FRONTAL SYSTEM WILL AFFECT
THE AREA. RAINY AND WINDY CONDITIONS WILL OCCUR WITH THIS
SYSTEM...WITH WIND ADVISORY LEVEL CONDITIONS POSSIBLE OVER THE NORTH
INTERIOR AND COAST. SNOW LEVELS ARE ALSO LOW ENOUGH WITH THIS SYSTEM
THAT WE COULD SEE A MODERATE AMOUNT OF SNOW AT HIGHER SKI AREAS AND
PASSES IN THE NORTH CASCADES. JSMITH

&&

.LONG TERM...A PROGRESSIVE PATTERN WILL PREVAIL SATURDAY THROUGH
TUESDAY WITH WEATHER SYSTEMS MOVING THROUGH THE AREA EVERY DAY OR
SO...KEEPING THE WEATHER RELATIVELY WET AND UNSETTLED. FOR NOW...A
SYSTEM MOVING ONSHORE ON MONDAY LOOKS LIKE THE STRONGEST OF THE
BUNCH. JSMITH/SCHNEIDER

&&

.HYDROLOGY...RIVER FLOODING IS NOT EXPECTED IN THE NEXT 7 DAYS.

&&

.AVIATION...AN UPPER LEVEL RIDGE OVER CENTRAL WA WILL CONTINUE
MOVING SLOWLY E TODAY AS A COLD FRONT JUST OFFSHORE APPROACHES W WA
FROM THE SW. MID AND HIGH LEVEL MOISTURE WITH CLOUD BASES 12000 FEET
AND ABOVE HAS BEEN STREAMING N OVER W WA AHEAD OF THE FRONT. CIGS
WILL REMAIN 8000 FT AND ABOVE THROUGH 02Z AND THEN WILL BEGIN
GRADUALLY LOWERING DOWN TO IFR/MVFR LEVELS AS THE FRONT CROSSES THE
AREA. FROPA ON THE CENTRAL COAST WILL BE AROUND 08Z AND OVER THE
INTERIOR AROUND 12Z.

KSEA...VFR CONDITIONS TODAY WITH CIGS BKN120 AND ABOVE. UNRESTRICTED
VISIBILITY. A COLD FRONT WILL MOVE NE ACROSS THE AREA LATE TONIGHT
WITH CIGS LOWERING TO MVFR LEVELS BETWEEN 06Z-12Z. SURFACE WINDS
WILL BE N-NE 3-8 KT THROUGH 00Z...THEN SHIFT TO SE BETWEEN 00Z-03Z.
KAM

&&

.MARINE...A COLD FRONT WILL APPROACH FROM THE SOUTHWEST TODAY THEN
MOVE NORTHEAST ACROSS W WA LATE TONIGHT. MODERATE SOUTHEAST FLOW
WILL DEVELOP WITH SMALL CRAFT ADVISORY WINDS EXPECTED OVER MOST
WATERS. POST FRONT SCA WINDS WILL CONTINUE OVER MOST WATERS THROUGH
THURSDAY MORNING.

A WEAKER TRAILING SYSTEM WILL HEAD TOWARD N CA ON THURSDAY AND WILL
HAVE NO IMPACT ON THE PACNW.

MODELS REMAIN CONSISTENT IN BRINGING A STRONGER FRONTAL SYSTEM FROM
THE WEST ON FRIDAY. THIS SYSTEM LOOKS LIKE IT WILL BRING SOUTHERLY
GALES TO THE COAST STARTING EARLY FRIDAY MORNING. FROPA ON THE COAST
LOOKS IT WILL BE AROUND MIDDAY FRIDAY. GALES ARE ALSO POSSIBLE OVER
THE NORTHERN INTERIOR WATERS. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     GALE WATCH COAST FRIDAY.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
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