Area Forecast Discussion
Issued by NWS Seattle/Tacoma, WA

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000
FXUS66 KSEW 272205
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
305 PM PDT SUN JUL 27 2014

.SYNOPSIS...HIGH PRESSURE ALOFT WILL REMAIN OVER THE REGION FOR
DRY WEATHER WITH ABOVE NORMAL DAYTIME TEMPERATURES THIS WEEK.

&&

.SHORT TERM...
AN UPPER RIDGE CENTERED OVER THE DESERT SOUTHWEST WILL CONTINUE
TO DOMINATE THE WEATHER PATTERN OVER THE PACIFIC NORTHWEST. THIS
WILL TRANSLATE TO DRY WEATHER WITH ABOVE NORMAL TEMPERATURES FOR
THE CWA. HOWEVER...WILL NEED TO KEEP AN EYE ON MOISTURE AND
INSTABILITY ON THE WESTERN PERIPHERY OF THE UPPER HIGH.
ALTHOUGH...STILL BELIEVE THAT ANY TSTMS SHOULD REMAIN SOUTH AND
EAST OF THE CWA.

MEANWHILE...WEAK LOW LEVEL ONSHORE FLOW WILL PERSIST FOR AREAS OF
STRATUS/FOG OVER MAINLY THE COAST. THERE SHOULD BE A SLIGHT
INCREASE IN COVERAGE TUE MORNING BUT EVEN MORE ON WED DUE TO A
TIGHTER ONSHORE PRESSURE GRADIENT.

.LONG TERM...
NO MAJOR CHANGES ARE EXPECTED IN THE LONG WAVE PATTERN DURING
THIS PERIOD. AN UPPER RIDGE WILL CONTINUE TO DOMINATE THE WEATHER
PATTERN OVER MUCH OF THE PACIFIC NORTHWEST. THE MAIN DIFFERENCES
IN THE MEDIUM RANGE SOLUTIONS WERE IN THE DETAILS. FOR EXAMPLE...
THE ECMWF CONTINUED TO ADVERTISE A WEAK UPPER LOW MOVING ACROSS
THE CWA DURING THE FRI NIGHT/SATURDAY MORNING TIME FRAME. FOR
NOW...CHOSE TO COMPROMISE BETWEEN THE ECMWF AND GFS SOLUTIONS.

&&

.AVIATION...THE UPPER LEVEL RIDGE OVER THE ROCKY MOUNTAINS WILL
CONTINUE TO BUILD THROUGH TUESDAY. (PIC10) THE FLOW ALOFT WILL
REMAIN SOUTHWESTERLY AND LIGHT TODAY. RISING HEIGHTS OVER THE REGION
WILL ALSO HELP KEEP THE AIR MASS OVER WESTERN WASHINGTON DRY AND
STABLE. WEAK LOW LEVEL ONSHORE FLOW GAVE LIMITED LOW CLOUDS TO THE
NORTH COAST AND STRAIT THIS MORNING AND THEY WILL CLEAR QUICKLY BY
MID TO LATE MORNING. SKIES WILL REMAIN CLEAR AND VFR ALL OTHER
AREAS.

KSEA...CLEAR SKIES AND VFR CONDITIONS THROUGH TONIGHT. NORTHERLY
WINDS TO 11 KTS THROUGH TONIGHT.

&&

.MARINE...THE PERSISTENT PATTERN OF HIGH PRESSURE OVER THE COASTAL
WATERS AND LOWER PRESSURE INLAND WILL CONTINUE THROUGH MID
WEEK...SUPPORTING VARYING DEGREES ONSHORE FLOW. (PIC11) STRONGEST
WINDS WILL OCCUR THROUGH THE CENTRAL AND EAST STRAIT...LIKELY
REACHING SMALL CRAFT ADVISORY LEVELS DURING THE LATE AFTERNOON AND
EVENING HOURS. NORTHWESTERLY WINDS OVER THE COASTAL WATERS WILL
STRENGTHEN THIS AFTERNOON AND EVENING WITH SCA WINDS POSSIBLE OVER
PARTS OF THE COASTAL WATERS. AREAS OF MORNING FOG OVER THE COASTAL
WATERS AND STRAIT THROUGH TUESDAY.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE COASTAL WATERS
     FROM JAMES ISLAND TO CAPE SHOALWATER OUT TO 60 NM AND THE
     CENTRAL/EASTERN STRAIT OF JUAN DE FUCA.

&&

$$

WWW.WEATHER.GOV/SEATTLE

FOR THE GRAPHICAL AFD...VISIT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML



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