Funnel Cloud in Washington, May 8, 2010

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
938 AM PDT SAT MAY 8 2010

.SYNOPSIS...A WEAK UPPER TROUGH AND LIGHT SURFACE FLOW WILL RESULT
IN MOSTLY SUNNY SKIES AND TEMPERATURES NEAR NORMAL ACROSS WESTERN
WASHINGTON TODAY. SHOWERS AND ISOLATED THUNDERSTORMS WILL BE LIMITED
TO THE MOUNTAINS DURING THE AFTERNOON AND EVENING. A WEAK UPPER
LEVEL RIDGE WILL MOVE THROUGH THE AREA ON SUNDAY. ANOTHER UPPER
TROUGH WILL MOVE ACROSS THE AREA MONDAY BRINGING A CHANCE OF
SHOWERS. AN UPPER RIDGE WILL BRING DRY WEATHER AGAIN FOR THE MIDDLE
OF NEXT WEEK.

&&

.SHORT TERM...ANOTHER PLEASANT DAY ON TAP FOR WESTERN WASHINGTON. A
WEAK UPPER LEVEL TROUGH IS PASSING THROUGH EASTERN WA WITH LIGHT
OFFSHORE PRES GRADIENTS ACROSS W WA. ALREADY SEEING SOME CUMULUS
OVER THE CASCADES WITH SCATTERED SHOWERS AND ISOLD T-STORMS ONCE
AGAIN THIS AFTERNOON. STEERING FLOW IS LIGHT WESTERLY SO CELLS
SHOULD DRIFT EAST OF THE CREST. TEMPERATURES WILL BE CLOSE TO
YESTERDAY/S WITH HIGHS IN THE UPPER 50S TO LOWER 60S NEAR THE
WATER...AND MID TO UPPER 60S INLAND.

QUIET WEATHER WILL CONTINUE ON SUNDAY WITH THE NEXT SYSTEM DIVING
SOUTH INTO CALIFORNIA. PRESSURE GRADIENTS WILL FLIP TO ONSHORE
DURING THE AFTERNOON WITH COOLER TEMPS EXPECTED ALONG THE COAST. THE
INTERIOR WILL SEE ANOTHER SUNNY DAY WITH HIGHS AGAIN IN THE 60S. LOW
CLOUDS WILL INCREASE SUN NIGHT AS THE MARINE LAYER PUSHES FARTHER
INLAND...LIKELY COVERING THE INTERIOR BY MON MORNING. SCATTERED
SHOWERS EXPECTED BY MON AFTERNOON AS ANOTHER TROUGH MOVES INLAND. 33

.LONG TERM...PREVIOUS DISCUSSION...EXTENDED MODELS IN FAIRLY GOOD
AGREEMENT THIS MORNING EARLY ON IN THE EXTENDED WITH THE UPPER LEVEL
LOW CONTINUING TO DIG TO THE SOUTHEAST MONDAY NIGHT INTO TUESDAY.
WILL LEAVE A CHANCE OF SHOWERS IN THE FORECAST FOR MONDAY NIGHT AT
THIS POINT BUT IF THE MODEL TRENDS CONTINUE TO WITH THE DIGGING OF
THE LOW WILL BE ABLE TO TAKE THE SHOWERS OUT OF THE LOWLANDS FOR
MONDAY NIGHT. UPPER LEVEL RIDGE OFFSHORE TUESDAY BUILDING OVER
WESTERN WASHINGTON TUESDAY NIGHT INTO WEDNESDAY. SURFACE GRADIENTS
NEVER REALLY TURN OFFSHORE SO DAYTIME HIGHS WILL ONCE AGAIN BE
WITHIN A COUPLE DEGREES OF NORMAL FOR THE MOST PART. SOME SMALL
DIFFERENCES IN THE MODEL SOLUTIONS ON THURSDAY WITH THE ECMWF
DISSIPATING THE NEXT FRONT TO APPROACH THE AREA MUCH FURTHER
OFFSHORE VERSUS THE GFS. BECAUSE OF THIS THE GFS BRINGS SOME LIGHT
PRECIPITATION TO THE MOUNTAINS ON THURSDAY AND WILL KEEP CHANCE POPS
GOING FOR THE MOUNTAINS ON THAT DAY. ANOTHER SYSTEM DEVELOPING
OFFSHORE ON FRIDAY AND THIS TIME THE ECMWF BRINGS THE SYSTEM CLOSER
TO THE COAST WHILE THE GFS KEEPS THE SYSTEM WELL TO THE WEST. BOTH
SOLUTIONS ARE DRY FOR FRIDAY. WILL WAIT FOR ANOTHER MODEL RUN OR TWO
BEFORE TAKING THE CLIMO POPS OUT OF DAY 7.

CLIMATE NOTE...THE 48 DEGREE HIGH ON WEDNESDAY FOR SEATTLE TIED FOR
THE 3RD COLDEST HIGH TEMPERATURE IN MAY AT SEATTLE TACOMA AIRPORT
AND WAS IN THE TOP 10 COLDEST MAY HIGH TEMPERATURES SINCE RECORDS
STARTED AT THE FEDERAL BUILDING BACK IN 1891. FELTON

&&

.AVIATION...A WEAK...UPPER TROF OVER THE REGION WILL MOVE E
OVERNIGHT. CONTINUED WLY FLOW ALOFT. MEANWHILE...THE AIR MASS WILL
REMAIN UNSTABLE ENOUGH FOR SCATTERED AFTERNOON AND EVENING TSTMS
OVER THE MOUNTAINS...MAINLY THE N CASCADES. TSTMS WILL BE MORE
ISOLATED OVER THE OLYMPIC RANGE. LOW LEVEL FLOW BECMG ONSHORE.

KSEA...VFR CONDITIONS WILL PREVAIL. TSTMS THIS AFTERNOON WILL STAY
WELL E OF THE TERMINAL.

&&

.MARINE...
THE FLOW WILL BECOME MORE ONSHORE WITH TIME THROUGH THIS WEEKEND.
EXPECT A WEAK FRONTAL SYSTEM TO PASS TO THE S OF THE AREA ON MON.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY IN EFFECT FOR THE CENTRAL AND EASTERN
     STRAIT OF JUAN DE FUCA FROM 5 PM TODAY TIL 11 PM TONIGHT..

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