Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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000
FXUS66 KSEW 250523
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
920 PM PST SAT JAN 24 2015

.SYNOPSIS...AN UPPER RIDGE IS OVER THE REGION. A WEAK FRONT WILL
DISSIPATE OVER WESTERN WASHINGTON TUESDAY. ANOTHER UPPER LEVEL RIDGE
WILL BUILD OVER THE REGION LATER IN THE WEEK.

&&

.SHORT TERM...THE WARM FRONT HAS SHIFTED NORTH INTO B.C. AND THE
WEATHER WILL BE DRY THROUGH MONDAY. LOWLAND TEMPS AND DEW POINTS ARE
IN THE LOWER TO MID 50S THIS EVENING...AND NOT SURPRISINGLY LOW
CLOUDS HAVE FORMED. THE FREEZING LEVEL AT KUIL WAS 12KFT THIS
AFTERNOON WITH THE WARM UPPER RIDGE PUSHED UP OVER THE REGION...WITH
A WARM AIR MASS IN PLACE HIGHS HAVE A CHANCE TO GET UP AROUND 60 THE
NEXT TWO DAYS...AS THEY DID TODAY IN A COUPLE SPOTS. A WEAK FRONT
WILL DISSIPATE AS IT REACHES THE AREA TUESDAY.

.LONG TERM...THE GFS AND CANADIAN SOLUTIONS SHOW A WEAK TROUGH
REMAINING OVER THE AREA ON WED THAT IS FOLLOWED BY ANOTHER WEAKENING
FRONT THU OR THU EVENING. THERE WILL LIKELY BE SOME PERIODS THAT
WILL BE DRY IN THE TUE NIGHT THROUGH THU NIGHT PERIOD...BUT MODEL
CONSISTENCY AND CONTINUITY WITH THESE VERY WEAK FEATURES IS NOT TOO
HIGH AT THIS TIME. AS A RESULT...FORECASTS WILL INDICATE CLOUDS AND
A CHANCE OF SHOWERS WITH LOWS IN THE 40S AND HIGHS IN THE LOWER TO
MID 50S.

THE EXTENDED MODELS CONTINUE TO SHOW RIDGING INCREASING ONCE AGAIN
OVER THE NORTHWEST THU NIGHT OR FRI AND CONTINUING THROUGH NEXT
WEEKEND. WITH THE RIDGE AXIS JUST OFFSHORE AND SURFACE HIGH OVER
SOUTHEASTERN BC...THE LOWER LEVEL AIR MASS...WHILE STILL MILD FOR
THIS TIME OF YEAR...WILL LIKELY NOT BE AS WARM AS THE ONE WE ARE
SEEING AT THIS TIME. ALBRECHT

&&

.HYDROLOGY...THE GAGES ON THE SNOQUALMIE RIVER SHOW THE RIVER
FLAT...AND ABOVE CARNATION THE RIVER IS RECEDING...FLOODING IS NOT
EXPECTED AND THE WARNING WAS CANCELLED.

&&

.AVIATION...UPPER LEVEL RIDGE OVER WESTERN WASHINGTON TONIGHT AND
SUNDAY WITH WESTERLY FLOW ALOFT. AT THE SURFACE MODERATE SOUTHERLY
FLOW WILL EASE TONIGHT AND BECOMING LIGHT OFFSHORE SUNDAY. AIR MASS
MOIST AND STABLE.

CEILINGS ARE GENERALLY BELOW 1000 FEET WITH LOCAL CEILINGS IN THE
1000-2000 FOOT RANGE. THERE HAS BEEN SOME BRIEF SCATTERING OUT OF
THE CLOUDS IN THE EARLY EVENING HOURS BUT WITH THE LOWER LEVELS SO
MOIST...DEW POINTS IN THE LOWER TO MID 50S...THE CLOUDS FILL BACK IN
AGAIN QUICKLY. WITH THE SOUTHERLY FLOW AND MOIST LOWER LEVELS WILL
STAY WITH THE IFR/LOW END OF MVFR CEILINGS INTO SUNDAY MORNING WITH
AREAS OF FOG DEVELOPING MAINLY ALONG THE COAST AND OVER THE
SOUTHWEST INTERIOR. CONDITIONS IMPROVING MIDDAY SUNDAY WITH JUST
SCATTERED CLOUDS BY MID AFTERNOON.

KSEA...CEILINGS AOB 1000 FEET INTO SUNDAY MORNING. COULD SEE A BRIEF
BREAKS IN THE CLOUDS IN THE NEXT THREE HOURS. WITH THE
SOUTHERLY GRADIENTS LOW VISIBILITY FOG...LESS THAN 1 SM...NOT
PROBABLE BUT COULD SEE SOME REDUCED VISIBILITIES IN THE 3-5SM RANGE
UNTIL 18Z. CLOUDS SCATTERING OUT SUNDAY AFTERNOON. LIGHT SOUTHERLY
WINDS BECOMING VARIABLE MIDDAY SUNDAY. FELTON

&&

.MARINE...SURFACE HIGH PRESSURE WILL BUILD FROM THE SOUTH THIS
EVENING WITH THE LOW LEVEL FLOW BECOMING LIGHT OFFSHORE ON SUNDAY.
THE LIGHT OFFSHORE FLOW PATTERN WILL CONTINUE INTO MONDAY. SMALL
CRAFT ADVISORY WINDS OVER THE CENTRAL AND NORTHERN OUTER COASTAL
WATERS EASING ON SUNDAY. SMALL CRAFT ADVISORIES FOR HAZARDOUS SEAS
FOR THE OUTER SOUTHERN COASTAL WATERS...INNER COASTAL WATERS AND
WEST ENTRANCE TO THE STRAIT TONIGHT. HAZARDOUS SEAS MAY CONTINUE
OVER THE OUTER WATERS THROUGH MONDAY.

A WEATHER SYSTEM WILL ARRIVE ON TUESDAY. THIS IS LIKELY TO BRING
SMALL CRAFT ADVISORY SOUTHERLY WINDS TO MOST AREAS AT TIMES FROM
MONDAY AFTERNOON THROUGH TUESDAY. SMALL CRAFT ADVISORY WESTERLY
WINDS ARE LIKELY IN THE STRAIT TUESDAY AFTERNOON. FELTON/BURKE

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS NORTHERN AND CENTRAL OUTER
     COASTAL WATERS.
     SMALL CRAFT ADVISORY HAZARDOUS SEAS INNER COASTAL WATERS
     ...WEST ENTRANCE TO THE STRAIT AND SOUTHERN OUTER COASTAL
     WATERS.
&&

$$

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