Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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FXUS66 KSEW 061022
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
220 AM PST FRI MAR 6 2015

.SYNOPSIS...A STRONG UPPER LEVEL RIDGE WILL REMAIN OVER THE PACIFIC
NORTHWEST THROUGH MONDAY NIGHT GIVING DRY CONDITIONS AND WARMER THAN
NORMAL TEMPERATURES. THE RIDGE WILL WEAKEN ON TUESDAY RESULTING IN A
PACIFIC WEATHER SYSTEM MOVING INTO THE AREA. EXPECT AN INCREASE IN
CLOUDS...A CHANCE OF RAIN...AND COOLER DAYTIME TEMPERATURES STARTING
THE MIDDLE OF NEXT WEEK.

&&

.SHORT TERM...SPECTACULAR EARLY SPRING WEATHER IS EXPECTED TODAY
THROUGH MONDAY.

A STRONG UPPER LEVEL RIDGE OF HIGH PRESSURE IS SITTING
ALONG THE WEST COAST THIS MORNING. SHORT TERM MODELS AMPLIFY THE
RIDGE AS IT BECOMES NEGATIVELY TILTED OVER THE OFFSHORE WATERS ON
SATURDAY. THE RIDGE WILL THEN FLATTEN A BIT AS IT SHIFTS INLAND
SUNDAY INTO MONDAY.

INFRARED SATELLITE IMAGERY STILL SHOWS QUITE A BIT OF CIRRUS
OFFSHORE THAT IS GETTING READY TO ROUND THE RIDGE AND MOVE INTO
WASHINGTON. HIGH CLOUDS AT TIMES WILL FILTER THE SUNSHINE...BUT IT
LOOKS TO BE A VERY NICE EARLY SPRING DAY WITH TEMPERATURES RISING
INTO THE MID 50S TO LOWER 60S ACROSS THE AREA. A FEW SHELTERED
PLACES IN THE SOUTH INTERIOR MAY HIT THE MID 60S.

NIGHTTIME TEMPERATURES OVER THE NEXT FEW DAYS WILL MODERATE TO NEAR
NORMAL AS DEWPOINT TEMPERATURES SLOWLY RISE. EXPECT MID 30S TO LOWER
40S. FOG EARLY THIS MORNING WILL BE QUITE PATCHY AND CONFINED TO THE
MOST SHELTERED VALLEYS OF THE SOUTH INTERIOR. EXPECT A SLIGHT
INCREASE IN MORNING FOG SATURDAY AND SUNDAY AS DEWPOINT TEMPERATURES
SLOWLY RISE.

TEMPERATURES ON SATURDAY MAY BE A TAD TRICKY AS SURFACE HIGH PRES
DEVELOPS OVER THE OFFSHORE WATERS ALONG 130W. WHILE MODEL PRES
GRADIENTS ARE LIGHT OVER WESTERN WASHINGTON...AFTERNOON SEA BREEZES
MAY HOLD TEMPERATURES IN THE UPPER 50S NEAR THE COASTAL BEACHES...IN
THE NORTH INTERIOR...AND NEAR THE WATERS OF PUGET SOUND. AREAS WELL
AWAY FROM WATER INFLUENCES WILL LIKELY GET BACK INTO THE LOWER TO
MID 60S ON SATURDAY. SUNDAY MAXIMUM TEMPERATURES ALSO LOOK TRICKY AS
THE LATEST 06Z GFS AND THE 00Z ECMWF BOTH SHOW ENOUGH SURFACE
RIDGING ALONG 130W TO RESULT IN SOME ENHANCEMENT TO THE AFTERNOON
SEA AND SOUND BREEZES. STILL...WITH THE SUNSHINE AND MILD
TEMPERATURES...GREENING GRASS...AND FLOWERING TREES AND BUSHES...NO
ONE WILL NOTICE --AND IF THE DO THEY WILL NOT LIKELY COMPLAIN.
ALBRECHT

.LONG TERM...AFTER ANOTHER VERY NICE DAY ON MONDAY...A TRANSITION
BACK TO MORE NORMAL MARCH CONDITIONS WILL BEGIN ON TUESDAY. MODEL
CONSENSUS FOR TUESDAY IS FOR A CHANCE OF RAIN...MAINLY COAST AND
LATER IN THE DAY. THE LATEST 3 RUNS OF THE GFS HAVE TRENDED TOWARD
THE ECMWF IN SHOWING A SOUTHERN STREAM SYSTEM APPROACHING THE AREA
FROM THE SOUTHWEST TUE NIGHT INTO THU RESULTING IN HIGH CHANCE TO
LIKELY POPS AND HIGH TEMPERATURES FALLING BACK INTO THE MID AND
UPPER 50S. THE AIR MASS WILL LIKELY BE RATHER WARM ACROSS THE AREA
BY MIDWEEK WITH LOW TEMPERATURES HOLDING IN THE MID AND UPPER 40S
ACROSS THE AREA.

RIDGING APPEARS TO WANT TO BUILD BACK INTO THE AREA LATE NEXT WEEK
FOR ANOTHER ROUND OF FINE EARLY SPRING WEATHER.

EXTENDED FORECASTS WERE NUDGED TOWARD A MODEL CONSENSUS SOLUTION.
ALBRECHT

&&

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

&&

.AVIATION...A STRONG RIDGE OF HIGH PRESSURE WILL CONTINUE TO
DOMINATE THE PAC NW. LIGHT WLY FLOW ALOFT WILL BECOME NWLY FRIDAY
NIGHT. AIR MASS IS STABLE AND DRY IN THE LOWER AND MID LEVELS.
SOMEWHAT MOIST AT THE HIGHER LEVELS RESULTING IN THICK CIRRUS AT
TIMES. AT THE SURFACE WINDS ARE LIGHT.

KSEA...LIGHT NE WIND LESS THAN 5 KT...BECOMING N/NW TO 5 KT AFTER
18Z.. HIGH CLOUDS AT TIMES WITH VFR CONDITIONS. DTM

&&

.MARINE...HIGH PRESSURE AT THE SURFACE AND WEAK GRADIENTS WILL
RESULT IN LIGHT WINDS OVER THE WATERS. ONSHORE FLOW WILL SLOWLY
DEVELOP MONDAY INTO TUESDAY. A FRONT IS FORECAST TO REACH THE
COASTAL WATERS TUESDAY NIGHT AND IT MAY BRING SMALL CRAFT ADVISORY
WINDS TO THE COAST. DTM

&&

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

&&

$$

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