weather.gov     
National Weather Service

Area Forecast Discussion
NWS Homepage
This page is being discontinued on March 12, 2014.
The same data is available at this site. Please update your bookmarks.
Thank you, and we apologize for the inconvenience.
Please send an email to SR-SRH.Webmaster@noaa.gov with any concerns.


Current Version
Previous Version:    01  02  03  04  05  06  07  08  09  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  
   31  
[Printable]
278
FXUS66 KSEW 012229
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PDT MON SEP 1 2014

.SYNOPSIS...A FRONT WILL BRING A LITTLE RAIN ON TUESDAY. HIGH
PRESSURE ALOFT WILL REBUILD OVER THE AREA FOR THE REST OF THE WEEK
FOR DRY AND WARMER WEATHER. COOLER AND CLOUDIER WEATHER WILL RETURN
EARLY NEXT WEEK AS ONSHORE FLOW INCREASES.

&&

.SHORT TERM...A FAIRLY VIGOROUS UPPER TROUGH AND ASSOCIATED COLD
FRONT WILL MOVE THROUGH THE AREA LATER TUESDAY. THIS SYSTEM WILL
BRING A LITTLE RAIN TO ALL AREAS WITH A PUGET SOUND CONVERGENCE ZONE
LINGERING INTO TUESDAY NIGHT. THE HIGHEST MOUNTAINS ELEVATIONS COULD
SEE A LITTLE SNOW TUESDAY NIGHT AS SNOW LEVELS DROP 7000-7500 FEET.

DRIER NORTHERLY FLOW ALOFT WILL DEVELOP TUESDAY NIGHT AND WEDNESDAY
AS HIGH PRESSURE ALOFT BUILDS OFFSHORE. A FEW SHOWERS WILL LINGER
INTO WEDNESDAY MORNING...MAINLY OVER THE CASCADES. OTHERWISE...DRY
WEATHER WILL RETURN WITH DECREASING CLOUDS ON WEDNESDAY. THURSDAY
SHOULD BE SUNNY AND A WARMER WITH HIGH PRESSURE ALOFT AND NORTHERLY
LOW LEVEL OFFSHORE FLOW DEVELOPING. SCHNEIDER

.LONG TERM...FRIDAY AND SATURDAY LOOK LIKE THE WARMEST DAYS OF THE
WEEK WITH HIGH PRESSURE ALOFT IN CONTROL. THE RIDGE WILL BEGIN TO
WEAKEN ON SATURDAY BUT THAT IS NOT EXPECTED TO HAVE MUCH IMPACT ON
TEMPERATURES OR CLOUD COVER.

IT LOOKS LIKE THERE WILL A MARINE PUSH SATURDAY NIGHT WITH AN UPPER
TROUGH MOVING OVER THE AREA ON SUNDAY AND MONDAY FOR COOLER AND
CLOUDIER WEATHER WITH A CHANCE OF SHOWERS AT TIMES. THE MODELS ARE
NOT IN GOOD AGREEMENT WITH THESE DETAILS HOWEVER. SCHNEIDER

&&

.AVIATION...LIGHT NW FLOW ALOFT WILL BECOME WESTERLY OVERNIGHT AND
STRENGTHEN TUESDAY AS VIGOROUS SYSTEM APPROACHES WASHINGTON FROM THE
NORTH. THE RELATIVELY MOIST AIR MASS HAS BECOME WEAKLY UNSTABLE THIS
AFTERNOON...AND THERE REMAINS A SLIGHT CHANCE OF SHOWERS...MAINLY
OVER THE NORTH COAST AND NORTH THIS AFTERNOON AS A VERY WEAK FRONT
MOVES ONSHORE AND FALLS APART. RADAR IMAGERY AND SURFACE
OBSERVATIONS CONFIRM THIS...SHOWING A FEW LIGHT SHOWERS MOVING
INLAND AS OF 21Z/2PM.  CEILINGS OVER MUCH OF THE INTERIOR HAVE
SCATTERED OUT OVER THE LAST COUPLE OF HOURS AND VFR CONDITIONS
PREVAIL. THE EXCEPTION IS THE STRAIT...SOUTHWEST INTERIOR...AND
CENTRAL WASHINGTON COAST WHERE A BKN BUT VFR DECK IS HANGING ON. THE
NORTH COAST HAS SEEN CEILINGS LOWER TO MVFR AND IFR LEVELS WITH THE
SHOWERS THAT HAVE MOVED ON SHORE THERE. EXPECT CONDITIONS ALL AREAS
TO IMPROVE OR REMAIN VFR THIS EVENING. THE COAST AND STRAIT AS WELL
AS THE SOUTHWEST INTERIOR MAY HAVE A TOUGH TIME SCATTERING
COMPLETELY OUT THIS EVENING. EXPECT CEILINGS TO FILL AND LOWER
THROUGH EARLY TUESDAY MORNING WITH MOST LOCATIONS BECOMING MVFR BY
DAYBREAK...WHILE THE COAST WILL LIKELY DROP TO IFR LEVELS.
INCREASING MID AND HIGH CLOUDS AS WELL AS SHOWERS TUESDAY WITH THE
APPROACHING UPPER LEVEL TROUGH.

KSEA...SW WIND 4-7 KT WILL BECOME N AFTER 00Z/5 PM...THEN NE AND
LIGHT AFTER 8Z/1AM. VFR CONDITIONS WILL PREVAIL THROUGH THIS
EVENING...THEN FILL AND LOWER EARLY TUESDAY MORNING TO MVFR LEVELS.
INCREASING SHOWERS TUESDAY.

&&

.MARINE...SOLID ONSHORE FLOW WILL DEVELOP AS GRADIENTS THROUGH THE
STRAIT TIGHTEN OVERNIGHT...BRINGING SMALL CRAFT WINDS TO THE CENTRAL
AND EAST STRAIT THROUGH EARLY TUESDAY MORNING. A MORE VIGOROUS
SYSTEM MOVING INTO THE AREA WATERS TUESDAY WILL BRING ANOTHER BOUT
OF WINDS TO AREA WATERS. EXPECT STRONG SOUTHWESTERLIES OVER THE
COASTAL WATERS FOLLOWED BY NORTHWESTERLIES BEHIND THE FRONT. ONSHORE
GRADIENTS REMAIN FORECAST TO BE STRONG TOMORROW EVENING. WINDS OVER
THE COASTAL WATERS AND MUCH OF THE STRAIT WILL LIKELY BE HIGH END
SMALL CRAFT...POSSIBLY REACHING GALE CRITERIA. HAVE ISSUED A GALE
WATCH FOR THE COASTAL WATERS AND CENTRAL AND EAST STRAIT TUESDAY
AFTERNOON THROUGH LATE TUESDAY NIGHT. GRADIENTS EASE ON WEDNESDAY
THEN RETURN TO A TYPICAL LATE SUMMER PATTERN THROUGH THE REST OF THE
WEEK.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY CENTRAL AND EASTERN STRAIT OF JUAN DE FUCA.
    .GALE WATCH COASTAL WATERS...CENTRAL AND EASTERN STRAIT OF JUAN
     DE FUCA TUESDAY AFTERNOON THROUGH WEDNESDAY MORNING.

&&

$$

WWW.WEATHER.GOV/SEATTLE

YOU CAN SEE AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML











U.S. Dept. of Commerce
NOAA National Weather Service
1325 East West Highway
Silver Spring, MD 20910
E-mail: w-nws.webmaster@noaa.gov
Page last modified: May 16, 2007
NATIONAL WEATHER SERVICE: for Safety, for Work, for Fun - FOR LIFE