Small Craft Advisory 79, NWS Seattle, WA

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 AM PDT THU APR 7 2016

.SYNOPSIS...AN UPPER RIDGE AND LOW LEVEL OFFSHORE FLOW WILL BRING
RECORD HIGHS TO MANY LOCATIONS TODAY. ONSHORE FLOW WILL RETURN
FRIDAY AFTERNOON AND SATURDAY WITH HIGHS COOLING BACK TO CLOSER TO
NORMAL OVER THE WEEKEND. WEAK WEATHER SYSTEMS COULD PRODUCE A
LITTLE RAIN AT TIMES EARLY NEXT WEEK.

&&

.SHORT TERM...STRONG HIGH PRESSURE ALOFT AND OFFSHORE FLOW WILL
BRING WARM AND DRY CONDITIONS TO WESTERN WASHINGTON TODAY. FORECAST
HIGH TEMPERATURES ARE IN THE 70S TO LOWER 80S ACROSS MUCH OF THE
REGION - A GOOD 20-25 DEGREES ABOVE NORMAL. THE COAST WILL SET NEW
RECORDS. HIGHS IN THE INTERIOR ARE VERY CLOSE TO THE RECORDS AS
WELL.

THE UPPER LEVEL RIDGE WILL SHIFT EAST AND INLAND ON FRIDAY WITH A
WEAK ONSHORE PUSH DEVELOPING. THE ONSHORE PUSH WILL BRING MARINE
CLOUDS TO THE COAST FOR COOLER CONDITIONS - HIGHS NEAR 60. THE
INTERIOR WILL REMAIN SUNNY AND WARM WITH TEMPERATURES IN THE 70S. A
STRONGER ONSHORE PUSH FRIDAY NIGHT WILL BRING COOLER MARINE AIR
FARTHER INLAND.

ONSHORE FLOW WILL PREVAIL OVER THE WEEKEND WITH TEMPERATURES CLOSE
TO NORMAL. THE COAST MAY SEE A LITTLE LIGHT RAIN OR DRIZZLE.
OTHERWISE WEAK RIDGING ALOFT WILL KEEP THE FORECAST DRY FOR THE
INTERIOR. 33

.LONG TERM...PREVIOUS DISCUSSION...EXTENDED MODELS NOT IN VERY GOOD
AGREEMENT AFTER SUNDAY. LOW LEVEL ONSHORE FLOW CONTINUING ON SUNDAY
WITH AN UPPER LEVEL RIDGE OVER THE AREA RESULTING IN MORNING CLOUDS
AND SOME AFTERNOON CLEARING FOR THE INTERIOR. THE RIDGE SHIFTS EAST
ON MONDAY. THE GFS HAS A WEAK SHORTWAVE REACHING THE COAST ON MONDAY.
THE ECMWF IS MUCH FURTHER NORTH WITH THIS FEATURE. ON TUESDAY THE
GFS DIGS A TROUGH OFFSHORE MUCH FURTHER SOUTH THAN THE ECMWF
BRINGING A THREAT OF SHOWERS TO THE AREA. THE ECMWF IS DRY. ON
WEDNESDAY THE ECMWF BRINGS A FRONT INTO WESTERN WASHINGTON. WITH
THE DEEPER TROUGH OFFSHORE ON THE GFS THIS FEATURE GOES INLAND
SOUTH OF THE AREA. CURRENT FORECAST HAS A BROADBRUSH MOSTLY CLOUDY
WITH CHANCE POPS MONDAY THROUGH WEDNESDAY AND GIVEN THE
INCONSISTENCIES IN THE MODELS WILL LEAVE THIS FORECAST ALONE THIS
MORNING. FELTON

&&

.AVIATION...A STRONG UPPER LEVEL RIDGE IS OVER WESTERN WASHINGTON
THIS MORNING...WITH NORTHERLY SURFACE WINDS. THE AIR MASS IS DRY
AND STABLE. THE UPPER RIDGE WILL WEAKEN A BIT AS IT SHIFTS SLOWLY
EAST OF THE CASCADES TONIGHT...AND LOW LEVEL MARINE MOISTURE WILL
MOVE ONTO THE WASHINGTON COAST.

THERE IS ISOLATED FOG AND LOW STRATUS IN THE NORTH INTERIOR OF
WESTERN WASHINGTON THIS MORNING...WHICH WILL BURN OFF BY 9 AM.
OTHERWISE THERE IS NO SIGNIFICANT CLOUD COVER BELOW 12000 FT. THERE
WILL BE LITTLE CHANCE THROUGH TONIGHT...EXCEPT AT THE COAST WHERE
MARINE STRATUS WILL BRING IFR CONDITIONS LATE TONIGHT.

KSEA...NORTH WINDS 10-16 KT...EASING TO 6-12 KT LATE TODAY AND
VEERING TO NORTHEAST TONIGHT. NO SIGNIFICANT CLOUD COVER BELOW
12000 FT. MCDONNAL

&&

.MARINE...SURFACE HIGH PRESSURE ALONG THE WEST SIDE OF THE
SOUTHERN CANADIAN ROCKIES AND LOW PRESSURE OVER THE OREGON
OFFSHORE WATERS ARE PRODUCING MODERATE OFFSHORE FLOW ACROSS
WESTERN WASHINGTON. SMALL CRAFT ADVISORY EAST TO SOUTHEAST WINDS
SHOULD CONTINUE THROUGH LATE AFTERNOON FOR THE COASTAL WATERS AS
WELL AS THE WEST ENTRANCE AND CENTRAL STRAIT.

THE THERMAL TROUGH WILL SHIFT SLOWLY INLAND ON FRIDAY...AND
ONSHORE FLOW WILL DEVELOP LATE IN THE DAY. GALE FORCE WESTERLIES
ARE POSSIBLE IN THE CENTRAL AND EASTERN STRAIT LATE FRIDAY AND FRIDAY
NIGHT...AND A GALE WATCH REMAINS IN EFFECT. SMALL CRAFT ADVISORY
WINDS ARE LIKELY OVER THE COASTAL WATERS...WEST ENTRANCE STRAIT...
ADMIRALTY INLET...AND NORTHERN INLAND WATERS. ONSHORE FLOW WILL
CONTINUE SATURDAY AND GRADUALLY EASE LATE THIS WEEKEND AND MONDAY.
MCDONNAL

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 2 PM PDT THIS AFTERNOON FOR COASTAL
     WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM-
     COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER 10
     TO 60 NM-COASTAL WATERS FROM POINT GRENVILLE TO CAPE
     SHOALWATER OUT 10 NM.

     SMALL CRAFT ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR CENTRAL
     U.S. WATERS STRAIT OF JUAN DE FUCA-COASTAL WATERS FROM CAPE
     FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL WATERS FROM
     CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-WEST ENTRANCE U.S.
     WATERS STRAIT OF JUAN DE FUCA.

     GALE WATCH FROM FRIDAY AFTERNOON THROUGH LATE FRIDAY NIGHT FOR
     CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA-EAST ENTRANCE
     U.S. WATERS STRAIT OF JUAN DE FUCA.

&&

WWW.WEATHER.GOV/SEATTLE

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