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000
FXUS66 KSEW 011131 CCA
AFDSEW

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE SEATTLE WA
431 AM PDT SUN MAY 1 2016

CORRECTED THE SYNOPSIS.

.SYNOPSIS...HIGH PRESSURE ALOFT WILL PREVAIL OVER THE AREA THROUGH
MONDAY. THIS COMBINED WITH LOW LEVEL OFFSHORE FLOW WILL RESULT IN
UNSEASONABLY WARM TEMPERATURES. THE HIGH WILL SHIFT EAST ON
TUESDAY...ALLOWING A LOW PRESSURE SYSTEM OFFSHORE TO APPROACH.
THIS WILL RESULT IN INCREASED SOUTHERLY FLOW ALOFT AND A STRONG
MARINE PUSH THAT WILL BRING COOLER AND UNSETTLED CONDITIONS.

&&

.SHORT TERM...
AN UPPER LEVEL RIDGE WILL PREVAIL OVER THE REGION THROUGH MONDAY...
ALTHOUGH THE RIDGE AXIS IS EXPECTED TO SHIFT EAST OVER THE NORTHERN
INTERMOUNTAIN WEST BY MONDAY. THE LOW LEVEL FLOW WILL REMAIN
OFFSHORE THROUGH AT LEAST MONDAY MORNING. THIS WILL RESULT IN
UNSEASONABLY WARM TEMPS ACROSS THE FORECAST AREA. A FEW SITES WILL
LIKELY COME CLOSE TO OR BREAK MAX TEMP RECORDS TODAY AND/OR
MONDAY.

THE LOW LEVEL FLOW WILL BECOME NEUTRAL OR LIGHT ONSHORE MONDAY
AFTERNOON. THE COAST SHOULD SEE SOME COOLING IN THE AFTERNOON BUT
THE INTERIOR WILL LIKELY BE AS WARM OR WARMER ON MONDAY THAN
TODAY.

INCREASING SOUTHERLY FLOW ALOFT ON MONDAY WILL ALLOW SOME MIDLEVEL
MOISTURE AND INSTABILITY TO MOVE NORTH ACROSS THE AREA MONDAY
NIGHT. THE SHORT RANGE ENSEMBLE FORECAST /SREF/ INDICATED SOME LOW
LIFTED INDICES AND DECENT CAPE VALUES FOR WESTERN WA MONDAY
EVENING ACROSS MAINLY THE SOUTHERN PART OF THE CWA. THEREFORE...
WENT ON AHEAD AND INTRODUCED A SLIGHT RISK OF TSTMS TO THE
SOUTHERN ZONES AND THE OLYMPIC RANGE.

THE UPPER LEVEL RIDGE WILL MOVE FARTHER EAST ON TUESDAY...ALLOWING
AN UPPER TROF OVER THE NORTHEAST PACIFIC TO APPROACH THE REGION.
THE MAIN IMPACT THIS SYSTEM WILL HAVE ON OUR WEATHER WILL BE TO
INITIATE A STRONG ONSHORE PUSH THAT WILL LEAD TO WELCOME COOLING
ACROSS THE AREA. THE AIR MASS WILL BE SOMEWHAT UNSTABLE...THUS
EXPECT A THREAT OF SHOWERS...ALONG WITH A RISK OF ISOLATED TSTMS
OVER MAINLY THE CASCADES IN THE AFTERNOON.

.LONG TERM...
THE UPPER FLOW PATTERN WILL BE SPLIT OVER THE WESTERN USA DURING
THIS PERIOD. THE UPPER TROF OFFSHORE ON TUESDAY WILL REMAIN
OFF THE WEST COAST ON WEDNESDAY...WITH MUCH OF THE ENERGY DIVING
SOUTH TOWARDS THE CA WATERS. EXPECT A CLOSED UPPER LOW ON THURSDAY
OFF THE CA COAST. THIS WILL PLACE WESTERN WA BETWEEN TROFS OVER CA
AND BRITISH COLUMBIA AND RIDGES OFFSHORE AND OVER THE ROCKIES.

BEYOND THURSDAY...THE UPPER LEVEL RIDGE OFFSHORE WILL BEGIN
BUILDING EAST OVER OUR AREA FOR A DECREASING THREAT OF SHOWERS AND
INCREASED SUNSHINE.

&&

.AVIATION...UPPER LEVEL RIDGE OFFSHORE WILL EVOLVE INTO A MUCH
STRONGER UPPER LEVEL RIDGE OVER WESTERN CANADA...WITH THE CENTER OF
HIGH PRESSURE OVER SOUTHERN BRITISH COLUMBIA. THIS WILL RESULT IN
NORTHEASTERLY FLOW ALOFT BECOMING MORE EASTERLY AS THE DAY
PROGRESSES TODAY. LOW LEVEL FLOW WILL BECOME MORE EAST TO
NORTHEASTERLY AS THE DAY PROGRESSES.

IR SATELLITE IMAGERY SHOWS MOSTLY CLEAR SKIES OVER WESTERN
WASHINGTON WITH SOME LINGERING HIGH LEVEL CLOUDS. THESE HIGH CLOUDS
WILL REMAIN GENERALLY FEW TO SCT THROUGH THE DAY TODAY...THOUGH
GENERALLY MOST SITES SHOULD SEE SKC CONDITIONS. SMR

KSEA...SOME HIGH CLOUDS AT TIMES. NORTHERLY WINDS THROUGHOUT THE DAY
TODAY...GENERALLY LESS THAN 10 KNOTS...EXCEPT FOR DURING THE
AFTERNOON...WHERE SPEEDS ARE EXPECTED TO PEAK AT AROUND 10-13
KNOTS. SMR

&&

.MARINE...UPPER LEVEL HIGH PRESSURE OFFSHORE EXTENDING INTO SOUTHERN
BRITISH COLUMBIA. WINDS OVER COASTAL WATERS HAVE SUBSIDED BELOW
SMALL CRAFT ADVISORY CRITERIA AND THUS INHERITED ADVISORY HAS BEEN
ALLOWED TO EXPIRE. LOW LEVEL OFFSHORE FLOW TODAY WITH THERMALLY
INDUCED TROUGH ALONG THE COAST. A RETURN TO LOW LEVEL ONSHORE FLOW
WILL OCCUR LATER MONDAY INTO TUESDAY WITH VARYING DEGREES OF ONSHORE
FLOW THROUGH THE END OF THE WEEK. FELTON/SMR

&&

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

&&

$$

WWW.WEATHER.GOV/SEATTLE

AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION CAN BE SEEN AT
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000
FXUS66 KSEW 011042
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
342 AM PDT SUN MAY 1 2016

.SYNOPSIS...HIGH PRESSURE ALOFT WILL PREVAIL OVER THE AREA THROUGH
MONDAY. THIS COMBINED WITH LOW LEVEL OFFSHORE FLOW WILL RESULT IN
UNSEASONABLY WARM TEMPERATURES. THE HIGH WILL SHIFT EAST ON
TUESDAY...ALLOWING A LOW PRESSURE SYSTEM OFFSHORE TO APPROACH.
THIS WILL RESULT IN INCREASED SOUTHERLY FLOW ALOFT ALONG WITH A
STRONG MARINE PUSH THAT WILL RESULT IN COOLER AND UNSETTLED
CONDITIONS.

&&

.SHORT TERM...
AN UPPER LEVEL RIDGE WILL PREVAIL OVER THE REGION THROUGH MONDAY...
ALTHOUGH THE RIDGE AXIS IS EXPECTED TO SHIFT EAST OVER THE NORTHERN
INTERMOUNTAIN WEST BY MONDAY. THE LOW LEVEL FLOW WILL REMAIN
OFFSHORE THROUGH AT LEAST MONDAY MORNING. THIS WILL RESULT IN
UNSEASONABLY WARM TEMPS ACROSS THE FORECAST AREA. A FEW SITES WILL
LIKELY COME CLOSE TO OR BREAK MAX TEMP RECORDS TODAY AND/OR
MONDAY.

THE LOW LEVEL FLOW WILL BECOME NEUTRAL OR LIGHT ONSHORE MONDAY
AFTERNOON. THE COAST SHOULD SEE SOME COOLING IN THE AFTERNOON BUT
THE INTERIOR WILL LIKELY BE AS WARM OR WARMER ON MONDAY THAN
TODAY.

INCREASING SOUTHERLY FLOW ALOFT ON MONDAY WILL ALLOW SOME MIDLEVEL
MOISTURE AND INSTABILITY TO MOVE NORTH ACROSS THE AREA MONDAY
NIGHT. THE SHORT RANGE ENSEMBLE FORECAST /SREF/ INDICATED SOME LOW
LIFTED INDICES AND DECENT CAPE VALUES FOR WESTERN WA MONDAY
EVENING ACROSS MAINLY THE SOUTHERN PART OF THE CWA. THEREFORE...
WENT ON AHEAD AND INTRODUCED A SLIGHT RISK OF TSTMS TO THE
SOUTHERN ZONES AND THE OLYMPIC RANGE.

THE UPPER LEVEL RIDGE WILL MOVE FARTHER EAST ON TUESDAY...ALLOWING
AN UPPER TROF OVER THE NORTHEAST PACIFIC TO APPROACH THE REGION.
THE MAIN IMPACT THIS SYSTEM WILL HAVE ON OUR WEATHER WILL BE TO
INITIATE A STRONG ONSHORE PUSH THAT WILL LEAD TO WELCOME COOLING
ACROSS THE AREA. THE AIR MASS WILL BE SOMEWHAT UNSTABLE...THUS
EXPECT A THREAT OF SHOWERS ALONG WITH A RISK OF ISOLATED TSTMS
OVER MAINLY THE CASCADES IN THE AFTERNOON.

.LONG TERM...
THE UPPER FLOW PATTERN WILL BE SPLIT OVER THE WESTERN USA DURING
THIS PERIOD. THE UPPER TROF OFFSHORE ON TUESDAY WILL REMAIN
OFFSHORE ON WEDNESDAY...WITH MUCH OF THE ENERGY DIVING SOUTH
TOWARDS THE CA WATERS. EXPECT A CLOSED UPPER LOW ON THURSDAY OFF
THE CA COAST. THIS WILL PLACE WESTERN WA BETWEEN TROFS OVER CA
AND BRITISH COLUMBIA AND RIDGES OFFSHORE AND OVER THE ROCKIES.

BEYOND THURSDAY...THE UPPER LEVEL RIDGE OFFSHORE WILL BEGIN
BUILDING EAST OVER OUR AREA FOR A DECREASING THREAT OF SHOWERS AND
INCREASED SUNSHINE.

&&

.AVIATION...UPPER LEVEL RIDGE OFFSHORE WILL EVOLVE INTO A MUCH
STRONGER UPPER LEVEL RIDGE OVER WESTERN CANADA...WITH THE CENTER OF
HIGH PRESSURE OVER SOUTHERN BRITISH COLUMBIA. THIS WILL RESULT IN
NORTHEASTERLY FLOW ALOFT BECOMING MORE EASTERLY AS THE DAY
PROGRESSES TODAY. LOW LEVEL FLOW WILL BECOME MORE EAST TO
NORTHEASTERLY AS THE DAY PROGRESSES.

IR SATELLITE IMAGERY SHOWS MOSTLY CLEAR SKIES OVER WESTERN
WASHINGTON WITH SOME LINGERING HIGH LEVEL CLOUDS. THESE HIGH CLOUDS
WILL REMAIN GENERALLY FEW TO SCT THROUGH THE DAY TODAY...THOUGH
GENERALLY MOST SITES SHOULD SEE SKC CONDITIONS. SMR

KSEA...SOME HIGH CLOUDS AT TIMES. NORTHERLY WINDS THROUGHOUT THE DAY
TODAY...GENERALLY LESS THAN 10 KNOTS...EXCEPT FOR DURING THE
AFTERNOON...WHERE SPEEDS ARE EXPECTED TO PEAK AT AROUND 10-13
KNOTS. SMR

&&

.MARINE...UPPER LEVEL HIGH PRESSURE OFFSHORE EXTENDING INTO SOUTHERN
BRITISH COLUMBIA. WINDS OVER COASTAL WATERS HAVE SUBSIDED BELOW
SMALL CRAFT ADVISORY CRITERIA AND THUS INHERITED ADVISORY HAS BEEN
ALLOWED TO EXPIRE. LOW LEVEL OFFSHORE FLOW TODAY WITH THERMALLY
INDUCED TROUGH ALONG THE COAST. A RETURN TO LOW LEVEL ONSHORE FLOW
WILL OCCUR LATER MONDAY INTO TUESDAY WITH VARYING DEGREES OF ONSHORE
FLOW THROUGH THE END OF THE WEEK. FELTON/SMR

&&

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

&&

$$

WWW.WEATHER.GOV/SEATTLE

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





000
FXUS66 KSEW 010349
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PDT SAT APR 30 2016

.SYNOPSIS...HIGH PRESSURE ALOFT WILL BRING DRY AND WARMER WEATHER
THROUGH MONDAY. SOUTHERLY FLOW ALOFT AND LOW LEVEL ONSHORE FLOW
WILL RETURN TUESDAY AND PERSIST FOR MOST OF THE REST OF THE WEEK
FOR A CHANCE OF SHOWERS AND COOLER TEMPERATURES. AN UPPER RIDGE
WILL BRING DRIER AND WARMER WEATHER AGAIN LATE IN THE WEEK.

&&

.SHORT TERM...DRY WEATHER WILL CONTINUE ACROSS WESTERN WA THIS
WEEKEND WITH AN UPPER LEVEL RIDGE OVER THE REGION. TEMPERATURES WERE
MILD TODAY AND MAINLY IN THE 60S...A FEW DEGREES ABOVE NORMAL. LOW
LEVEL OFFSHORE FLOW WILL INCREASE ON SUNDAY AS A THERMAL TROUGH
FORMS ALONG THE COAST. THE AIR MASS WILL WARM FURTHER AND WE WILL
SEE AFTERNOON TEMPERATURES IN THE 70S TO LOWER 80S...MAINLY ACROSS
THE INTERIOR AND COAST. THE BROAD UPPER LEVEL RIDGE WILL BRING ONE
MORE WARM DAY ON MONDAY WITH HIGHS REACHING THE MID 80S IN THE
INTERIOR. SOME MID LEVEL MOISTURE MAY SPREAD NORTH AS WE MOVE INTO
TUESDAY FOR A CHANCE OF SHOWERS...WITH THUNDERSTORMS POSSIBLE OVER
THE CASCADES. THE LOW LEVEL FLOW WILL FLIP BACK TO ONSHORE WITH
TEMPERATURES TRENDING BACK TO NORMAL. MOIST SOUTHERLY FLOW WILL
CONTINUE ON WEDNESDAY FOR ADDITIONAL SHOWERS. 33

.LONG TERM...PREVIOUS DISCUSSION...AN UPPER TROUGH NEAR 130W WILL
SLOWLY SHIFT EAST AND SPLIT...TURNING INTO A CLOSED UPPER LOW ON
THURSDAY OVER CALIFORNIA. MOIST AND SLIGHTLY UNSTABLE SOUTHERLY FLOW
ALOFT WILL CONTINUE FOR WESTERN WASHINGTON...KEEPING A CHANCE OF
SHOWERS IN THE FORECAST. HIGHS WILL BE MOSTLY IN THE 60S.

AN UPPER RIDGE WILL MOVE OVER THE AREA ON FRIDAY AS THE UPPER LOW
TO THE SOUTH MOVES FARTHER SOUTH AND EAST. THIS WILL BRING DRIER
AND SLIGHTLY WARMER WEATHER TO WESTERN WASHINGTON. THE RIDGE
SHOULD BE IN CONTROL BY SATURDAY FOR A MOSTLY SUNNY DAY WITH HIGHS
INTO THE 70S AGAIN FOR SOME LOCATIONS. SCHNEIDER

&&

.AVIATION...UPPER LEVEL RIDGE OFFSHORE EXTENDING INTO SOUTHERN
BRITISH COLUMBIA WITH NORTHEASTERLY FLOW ALOFT. LOW LEVEL
NORTHWESTERLY ONSHORE FLOW TURNING OFFSHORE ON SUNDAY.

LAST BITS OF VISIBLE SATELLITE IMAGERY WESTERN WASHINGTON MOSTLY
CLEAR ASIDE FROM A FEW HIGH CLOUDS HERE AND THERE. THESE HIGH CLOUDS
LIKELY TO REMAIN FEW TO SCATTERED OVERNIGHT AND THROUGH SUNDAY.

KSEA...SOME HIGH CLOUDS AT TIMES. NORTHERLY WIND 8 TO 14 KNOTS
BECOMING NORTHEAST 4 TO 8 KNOTS AFTER 06Z. FELTON/SMR

&&

.MARINE...HIGH PRESSURE OFFSHORE EXTENDING INTO SOUTHERN
BRITISH COLUMBIA. SMALL CRAFT ADVISORY NORTHWESTERLIES WILL COME TO
AN END OVER THE COASTAL WATERS OVERNIGHT. LOW LEVEL FLOW TURNING
OFFSHORE ON SUNDAY WITH THERMALLY INDUCED TROUGH ALONG THE COAST. A
RETURN TO LOW LEVEL ONSHORE FLOW WILL OCCUR LATER MONDAY INTO
TUESDAY WITH VARYING DEGREES OF ONSHORE FLOW THROUGH THE END OF THE
WEEK. FELTON

&&

.CLIMATE...APRIL 2016 WILL BE THE WARMEST APRIL ON RECORD IN
SEATTLE. WHAT DOES A WARM APRIL MEAN FOR MAY TEMPERATURES? LOOKING
AT THE PREVIOUS TOP 10 WARMEST APRILS AT SEA-TAC AIRPORT THE
FOLLOWING MAY WAS WARMER THAN NORMAL 7 TIMES AND COOLER THAN NORMAL
3 TIMES. THREE OF THE FOLLOWING MAYS ARE IN THE TOP 10 WARMEST MAYS
FOR SEA-TAC. RECORDS STARTED AT SEA-TAC AIRPORT IN 1945. FELTON

&&

.SEW WATCHES/WARNINGS/ADVISORIES...

WA...NONE.

PZ...SMALL CRAFT ADVISORY COASTAL WATERS.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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





000
FXUS66 KSEW 302200
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PDT SAT APR 30 2016

.SYNOPSIS...HIGH PRESSURE ALOFT WILL BRING DRY AND WARMER WEATHER
THROUGH MONDAY. SOUTHERLY FLOW ALOFT AND LOW LEVEL ONSHORE FLOW
WILL RETURN TUESDAY AND PERSIST FOR MOST OF THE REST OF THE WEEK
FOR A CHANCE OF SHOWERS AND COOLER TEMPERATURES. AN UPPER RIDGE
WILL BRING DRIER AND WARMER WEATHER AGAIN LATE IN THE WEEK.

&&

.SHORT TERM...HIGH PRESSURE ALOFT WILL SHIFT INLAND SUNDAY WITH
LOW LEVEL OFFSHORE FLOW DEVELOPING FOR WESTERN WASHINGTON. HIGHS
WILL RISE INTO THE 70S OR EVEN LOWER 80S IN A FEW SPOTS.

THE HIGH PRESSURE ALOFT WILL SHIFT A LITTLE FURTHER INLAND MONDAY
WITH INCREASING SOUTHERLY FLOW ALOFT. LOW LEVEL OFFSHORE FLOW
WILL EASE BUT A WEAK SURFACE TROUGH WILL REMAIN JUST OFFSHORE.
THIS SHOULD BE THE WARMEST DAY FOR THE INTERIOR...A FEW DEGREES
WARMER THAN SUNDAY. THE COAST WILL REMAIN ABOVE NORMAL BUT
PROBABLY SEE A FEW DEGREES OF COOLING AS SOUTHERLY WINDS DEVELOP
IN THE AFTERNOON.

ONSHORE FLOW WILL INCREASE ALL AREAS TUESDAY WITH AN UPPER TROUGH
MOVING TO NEAR 130W. THE WILL BRING A CHANCE OF SHOWERS TO ALL
AREA AND HIGHS WILL COOL MOSTLY BACK INTO THE 60S. THE AIR WILL BE
UNSTABLE ENOUGH FOR A CHANCE OF THUNDERSTORMS OVER THE CASCADES IN
THE AFTERNOON AND EVENING. SCHNEIDER

.LONG TERM...AN UPPER TROUGH NEAR 130W WILL SLOWLY SHIFT EAST AND
SPLIT...TURNING INTO A CLOSED UPPER LOW ON THURSDAY OVER
CALIFORNIA. MOIST AND SLIGHTLY UNSTABLE SOUTHERLY FLOW ALOFT WILL
CONTINUE FOR WESTERN WASHINGTON...KEEPING A CHANCE OF SHOWERS IN
THE FORECAST. HIGHS WILL BE MOSTLY IN THE 60S.

AN UPPER RIDGE WILL MOVE OVER THE AREA ON FRIDAY AS THE UPPER LOW
TO THE SOUTH MOVES FARTHER SOUTH AND EAST. THIS WILL BRING DRIER
AND SLIGHTLY WARMER WEATHER TO WESTERN WASHINGTON. THE RIDGE
SHOULD BE IN CONTROL BY SATURDAY FOR A MOSTLY SUNNY DAY WITH HIGHS
INTO THE 70S AGAIN FOR SOME LOCATIONS. SCHNEIDER

&&

.AVIATION...UPPER LEVEL RIDGE OFFSHORE EXTENDING INTO SOUTHERN
BRITISH COLUMBIA WITH NORTHEASTERLY FLOW ALOFT. LOW LEVEL
NORTHWESTERLY ONSHORE FLOW TURNING OFFSHORE ON SUNDAY.

SATELLITE IMAGERY SHOWS ISOLATED SC OVER WESTERN WASHINGTON THIS
AFTERNOON. THE SC WILL DISSIPATE BY SUNSET LEAVING JUST SOME HIGH
CLOUDS AT TIMES THROUGH SUNDAY.

KSEA...SOME HIGH CLOUDS AT TIMES. NORTHERLY WIND 8 TO 14 KNOTS
BECOMING NORTHEAST 4 TO 8 KNOTS AFTER 06Z. FELTON

&&

.MARINE...HIGH PRESSURE OFFSHORE EXTENDING INTO SOUTHERN
BRITISH COLUMBIA. SMALL CRAFT ADVISORY NORTHWESTERLIES WILL COME TO
AN END OVER THE COASTAL WATERS OVERNIGHT. LOW LEVEL FLOW TURNING
OFFSHORE ON SUNDAY WITH THERMALLY INDUCED TROUGH ALONG THE COAST. A
RETURN TO LOW LEVEL ONSHORE FLOW WILL OCCUR LATER MONDAY INTO
TUESDAY WITH VARYING DEGREES OF ONSHORE FLOW THROUGH THE END OF THE
WEEK. FELTON

&&

.CLIMATE...APRIL 2016 WILL BE THE WARMEST APRIL ON RECORD IN
SEATTLE. WHAT DOES A WARM APRIL MEAN FOR MAY TEMPERATURES? LOOKING
AT THE PREVIOUS TOP 10 WARMEST APRILS AT SEA-TAC AIRPORT...THE
FOLLOWING MAY WAS WARMER THAN NORMAL 7 TIMES AND COOLER THAN
NORMAL 3 TIMES. THREE OF THE FOLLOWING MAYS ARE IN THE TOP 10
WARMEST MAYS FOR SEA-TAC. RECORDS STARTED AT SEA-TAC AIRPORT IN
1945. FELTON

&&

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

&&

$$

WWW.WEATHER.GOV/SEATTLE

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





000
FXUS66 KSEW 301611
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
911 AM PDT SAT APR 30 2016

.SYNOPSIS...HIGH PRESSURE ALOFT WILL BRING DRY AND WARMER WEATHER
THROUGH MONDAY. SOUTHERLY FLOW ALOFT AND LOW LEVEL ONSHORE FLOW
WILL RETURN TUESDAY AND PERSIST FOR MOST OF THE REST OF THE WEEK
FOR A CHANCE OF SHOWERS AND COOLER TEMPERATURES.

&&

.SHORT TERM...AN UPPER RIDGE WILL BUILD OVER THE AREA TODAY FOR
MOSTLY SUNNY AND WARMER WEATHER. HIGHS WILL BE MAINLY IN THE 60S.
THE RIDGE WILL SHIFT A BIT INLAND SUNDAY WITH LOW LEVEL OFFSHORE
FLOW DEVELOPING. HIGHS WILL JUMP 10-15 DEGREES WITH 70S COMMON AND
LOWER 80S POSSIBLE IN A FEW SPOTS.

HIGH PRESSURE ALOFT WILL SHIFT FURTHER INLAND MONDAY WITH
INCREASING SOUTHERLY FLOW ALOFT FOR WESTERN WASHINGTON. LOW LEVEL
OFFSHORE FLOW WILL DECREASE A BIT BUT A WEAK TROUGH WILL REMAIN
JUST OFFSHORE. THIS SHOULD BE THE WARMEST DAY FOR THE INTERIOR...A
FEW DEGREES WARMER THAN SUNDAY. THE COAST WILL REMAIN WELL ABOVE
NORMAL BUT PROBABLY SEE A FEW DEGREES OF COOLING AS SOUTHERLY
WINDS DEVELOP IN THE AFTERNOON. SCHNEIDER

.LONG TERM...PREVIOUS DISCUSSION...THE WEATHER PATTERN OVER THE
AREA TUESDAY THROUGH FRIDAY OF THE UPCOMING WEEK WILL BE SOMEWHAT
UNSETTLED. AN OMEGA BLOCK WILL BE OVER THE USA...WITH UPPER LEVEL
TROFS OVER THE WEST AND EAST COASTS. IT APPEARED THAT MUCH OF THE
ENERGY WITH THE WEST COAST TROF WILL IMPACT THE SOUTHWEST USA BUT
THERE WILL STILL BE A THREAT OF SHOWERS OVER THE FORECAST AREA.
OTHERWISE...EXPECT ONSHORE FLOW ACROSS WESTERN WA DURING THIS
PERIOD...WITH TEMPS RETURNING TO NEAR NORMAL.

&&

.AVIATION...UPPER LEVEL RIDGE OFFSHORE WILL BUILD INTO SOUTHERN
BRITISH COLUMBIA LATER TODAY AND TONIGHT. NORTHERLY FLOW ALOFT WILL
BECOME NORTHEASTERLY TONIGHT. LOW LEVEL NORTHWESTERLY ONSHORE FLOW
IS EXPECTED TO PERSIST TODAY.

SATELLITE IMAGERY SHOWS A LITTLE BIT OF SC OVER WESTERN WASHINGTON
THIS MORNING. SOME ISOLATED CEILINGS NEAR 4000 FEET. FOR THE MOST
PART THE SC DECK IS SCATTERED. THE FEW LOCATIONS WHERE THE SC DECK
IS BROKEN THIS MORNING THE SC DECK WILL BECOME SCATTERED BY NOON.
SKIES CLEARING OUT TONIGHT.

KSEA...TEMPORARY CEILINGS NEAR 4000 FEET THIS MORNING OTHERWISE
SCATTERED SC DECK WITH HIGH CLOUDS. SKIES CLEARING OUT TONIGHT.
LIGHT WIND BECOMING NORTHWESTERLY 5 TO 10 KNOTS MID
AFTERNOON. FELTON

&&

.MARINE...LOW LEVEL ONSHORE FLOW PATTERN CONTINUING TODAY
WITH SMALL CRAFT ADVISORIES PERSISTING OVER COASTAL WATERS THROUGH
TONIGHT. SMALL CRAFT WINDS WILL RETURN TO THE ENTIRE STRAIT LATE
THIS AFTERNOON AND INTO TONIGHT BEFORE DIMINISHING ONCE MORE.
NORTHWESTERLY ONSHORE FLOW TODAY AS HIGH PRESSURE BUILDS INTO
SOUTHERN BRITISH COLUMBIA. LOW LEVEL FLOW TURNING OFFSHORE ON SUNDAY
WITH THERMALLY INDUCED TROUGH ALONG THE COAST. A RETURN TO LOW LEVEL
ONSHORE FLOW WILL OCCUR LATER MONDAY INTO TUESDAY. FELTON

&&

.CLIMATE...APRIL 2016 WILL BE THE WARMEST APRIL ON RECORD IN
SEATTLE. WHAT DOES A WARM APRIL MEAN FOR MAY TEMPERATURES? LOOKING
AT THE PREVIOUS TOP 10 WARMEST APRILS AT SEA-TAC AIRPORT...THE
FOLLOWING MAY WAS WARMER THAN NORMAL 7 TIMES AND COOLER THAN
NORMAL 3 TIMES. THREE OF THE FOLLOWING MAYS ARE IN THE TOP 10
WARMEST MAYS FOR SEA-TAC. RECORDS STARTED AT SEA-TAC AIRPORT IN
1945. FELTON

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 5 AM PDT SUNDAY FOR COASTAL WATERS
     FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL
     WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-COASTAL
     WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM-
     COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE OUT 10
     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 FROM 5 PM THIS AFTERNOON TO 2 AM PDT SUNDAY
     FOR CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA-EAST
     ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA-WEST 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





000
FXUS66 KSEW 301611
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
911 AM PDT SAT APR 30 2016

.SYNOPSIS...HIGH PRESSURE ALOFT WILL BRING DRY AND WARMER WEATHER
THROUGH MONDAY. SOUTHERLY FLOW ALOFT AND LOW LEVEL ONSHORE FLOW
WILL RETURN TUESDAY AND PERSIST FOR MOST OF THE REST OF THE WEEK
FOR A CHANCE OF SHOWERS AND COOLER TEMPERATURES.

&&

.SHORT TERM...AN UPPER RIDGE WILL BUILD OVER THE AREA TODAY FOR
MOSTLY SUNNY AND WARMER WEATHER. HIGHS WILL BE MAINLY IN THE 60S.
THE RIDGE WILL SHIFT A BIT INLAND SUNDAY WITH LOW LEVEL OFFSHORE
FLOW DEVELOPING. HIGHS WILL JUMP 10-15 DEGREES WITH 70S COMMON AND
LOWER 80S POSSIBLE IN A FEW SPOTS.

HIGH PRESSURE ALOFT WILL SHIFT FURTHER INLAND MONDAY WITH
INCREASING SOUTHERLY FLOW ALOFT FOR WESTERN WASHINGTON. LOW LEVEL
OFFSHORE FLOW WILL DECREASE A BIT BUT A WEAK TROUGH WILL REMAIN
JUST OFFSHORE. THIS SHOULD BE THE WARMEST DAY FOR THE INTERIOR...A
FEW DEGREES WARMER THAN SUNDAY. THE COAST WILL REMAIN WELL ABOVE
NORMAL BUT PROBABLY SEE A FEW DEGREES OF COOLING AS SOUTHERLY
WINDS DEVELOP IN THE AFTERNOON. SCHNEIDER

.LONG TERM...PREVIOUS DISCUSSION...THE WEATHER PATTERN OVER THE
AREA TUESDAY THROUGH FRIDAY OF THE UPCOMING WEEK WILL BE SOMEWHAT
UNSETTLED. AN OMEGA BLOCK WILL BE OVER THE USA...WITH UPPER LEVEL
TROFS OVER THE WEST AND EAST COASTS. IT APPEARED THAT MUCH OF THE
ENERGY WITH THE WEST COAST TROF WILL IMPACT THE SOUTHWEST USA BUT
THERE WILL STILL BE A THREAT OF SHOWERS OVER THE FORECAST AREA.
OTHERWISE...EXPECT ONSHORE FLOW ACROSS WESTERN WA DURING THIS
PERIOD...WITH TEMPS RETURNING TO NEAR NORMAL.

&&

.AVIATION...UPPER LEVEL RIDGE OFFSHORE WILL BUILD INTO SOUTHERN
BRITISH COLUMBIA LATER TODAY AND TONIGHT. NORTHERLY FLOW ALOFT WILL
BECOME NORTHEASTERLY TONIGHT. LOW LEVEL NORTHWESTERLY ONSHORE FLOW
IS EXPECTED TO PERSIST TODAY.

SATELLITE IMAGERY SHOWS A LITTLE BIT OF SC OVER WESTERN WASHINGTON
THIS MORNING. SOME ISOLATED CEILINGS NEAR 4000 FEET. FOR THE MOST
PART THE SC DECK IS SCATTERED. THE FEW LOCATIONS WHERE THE SC DECK
IS BROKEN THIS MORNING THE SC DECK WILL BECOME SCATTERED BY NOON.
SKIES CLEARING OUT TONIGHT.

KSEA...TEMPORARY CEILINGS NEAR 4000 FEET THIS MORNING OTHERWISE
SCATTERED SC DECK WITH HIGH CLOUDS. SKIES CLEARING OUT TONIGHT.
LIGHT WIND BECOMING NORTHWESTERLY 5 TO 10 KNOTS MID
AFTERNOON. FELTON

&&

.MARINE...LOW LEVEL ONSHORE FLOW PATTERN CONTINUING TODAY
WITH SMALL CRAFT ADVISORIES PERSISTING OVER COASTAL WATERS THROUGH
TONIGHT. SMALL CRAFT WINDS WILL RETURN TO THE ENTIRE STRAIT LATE
THIS AFTERNOON AND INTO TONIGHT BEFORE DIMINISHING ONCE MORE.
NORTHWESTERLY ONSHORE FLOW TODAY AS HIGH PRESSURE BUILDS INTO
SOUTHERN BRITISH COLUMBIA. LOW LEVEL FLOW TURNING OFFSHORE ON SUNDAY
WITH THERMALLY INDUCED TROUGH ALONG THE COAST. A RETURN TO LOW LEVEL
ONSHORE FLOW WILL OCCUR LATER MONDAY INTO TUESDAY. FELTON

&&

.CLIMATE...APRIL 2016 WILL BE THE WARMEST APRIL ON RECORD IN
SEATTLE. WHAT DOES A WARM APRIL MEAN FOR MAY TEMPERATURES? LOOKING
AT THE PREVIOUS TOP 10 WARMEST APRILS AT SEA-TAC AIRPORT...THE
FOLLOWING MAY WAS WARMER THAN NORMAL 7 TIMES AND COOLER THAN
NORMAL 3 TIMES. THREE OF THE FOLLOWING MAYS ARE IN THE TOP 10
WARMEST MAYS FOR SEA-TAC. RECORDS STARTED AT SEA-TAC AIRPORT IN
1945. FELTON

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 5 AM PDT SUNDAY FOR COASTAL WATERS
     FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL
     WATERS FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-COASTAL
     WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM-
     COASTAL WATERS FROM JAMES ISLAND TO POINT GRENVILLE OUT 10
     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 FROM 5 PM THIS AFTERNOON TO 2 AM PDT SUNDAY
     FOR CENTRAL U.S. WATERS STRAIT OF JUAN DE FUCA-EAST
     ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA-WEST 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





000
FXUS66 KSEW 301032
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
332 AM PDT SAT APR 30 2016

.SYNOPSIS...HIGH PRESSURE ALOFT WILL BUILD OVER THE REGION THIS
WEEKEND. THIS COMBINED WITH THE LOW LEVEL FLOW BECOMING OFFSHORE
WILL RESULT IN TEMPERATURES CLIMBING ABOVE NORMAL FOR THIS TIME OF
THE YEAR. UNSEASONABLY WARM WEATHER WILL PERSIST ON MONDAY.

&&

.SHORT TERM...
AN UPPER LEVEL RIDGE WILL BUILD OVER THE REGION THIS WEEKEND. THIS
COMBINED WITH THE LOW LEVEL FLOW BECOMING OFFSHORE WILL RESULT IN
ANOTHER PERIOD OF WARM WEATHER. TEMPERATURES TODAY WILL BE ABOVE
NORMAL FOR THIS TIME OF THE YEAR OR GENERALLY FIVE TO DEGREES
WARMER THAN YESTERDAY. A THERMALLY INDUCED AREA OR LOW PRESSURE
ALONG OR JUST OFF THE COAST ON SUNDAY WILL RESULT IN UNSEASONABLE
WARM TEMPERATURES OR TEMPS ONE WOULD EXPECT DURING THE SUMMER.

THE FORECAST FOR MONDAY WILL BE A LITTLE TRICKY. THE SURFACE LOW
OFF THE OREGON COAST IS ANTICIPATED TO SHIFT NORTH DURING THE
DAY. THIS MAY INDUCE A LOW LEVEL SURGE OF MARITIME AIR UP THE
COAST IN THE AFTERNOON...THUS TEMPS ON THE COAST MIGHT BE A LITTLE
COOLER OR A LOT COOLER...DEPENDING ON WHICH MODEL ONE PREFERS. THE
NAM GUIDANCE FOR KHQM...FOR EXAMPLE...HAS A HIGH 68 DEGREES FOR
MONDAY...WHICH WAS ELEVEN DEGREES COOLER THAN ITS FORECAST FOR
SUNDAY. IN CONTRAST...THE GFS HAD A HIGH OF 73 DEGREES FOR KHQM
FOR MONDAY...OR ONLY FIVE DEGREES COOLER THAN ITS FORECAST FOR
SUNDAY. DECIDED TO GO WITH THE GFS SOLUTION FOR NOW DUE TO
UNCERTAINTY IN THE SURFACE FEATURES.

ACROSS THE INTERIOR...EXPECT TEMPS ON MONDAY TO BE A FEW DEGREES
WARMER THAN ON SUNDAY...WITH A FEW SITES HAVING A GOOD CHANCE OF
BREAKING RECORDS FOR THE DATE.

STRONG SOUTHERLY FLOW ALOFT IS EXPECTED TO DEVELOP MONDAY NIGHT.
THIS WILL ALLOW SOME MIDLEVEL MOISTURE AND INSTABILITY TO ADVECT
OVER MAINLY THE SOUTHERN PART OF THE FORECAST AREA FOR A LOW
THREAT OF SHOWERS. IF THE LATEST SREF IS CORRECT...THERE IS ALSO A
POSSIBILITY OF ISOLATED TSTMS MONDAY NIGHT OVER THE CENTRAL
CASCADES.

.LONG TERM...
THE WEATHER PATTERN OVER THE AREA TUESDAY THROUGH FRIDAY OF THE
UPCOMING WEEK WILL BE SOMEWHAT UNSETTLED. AN OMEGA BLOCK WILL
BE OVER THE USA...WITH UPPER LEVEL TROFS OVER THE WEST AND EAST
COASTS. IT APPEARED THAT MUCH OF THE ENERGY WITH THE WEST COAST
TROF WILL IMPACT THE SOUTHWEST USA BUT THERE WILL STILL BE A
THREAT OF SHOWERS OVER THE FORECAST AREA. OTHERWISE...EXPECT
ONSHORE FLOW ACROSS WESTERN WA DURING THIS PERIOD...WITH TEMPS
RETURNING TO NEAR NORMAL.

&&

.AVIATION...UPPER LEVEL RIDGING WILL CONTINUE TO BUILD OFFSHORE
TODAY. NORTHERLY FLOW ALOFT WILL TRANSITION TO BECOME NORTHEASTERLY
TONIGHT. LOW LEVEL ONSHORE FLOW IS EXPECTED TO PERSIST TODAY.

OBS FROM KSEA AND KBFI SHOW THAT CIGS ARE STARTING TO LOWER...WHILE
OBS FROM REMAINING TAF SITES CONTINUE TO SHOW GENERALLY CLEAR
CONDITIONS. IR SATELLITE IMAGERY HOWEVER DOES HINT AT AN INCREASE IN
CLOUD COVER...SO WOULD EXPECT A TRANSITION FROM GENERALLY CLEAR
SKIES TO MORE BROKEN TO OVERCAST CONDITIONS THIS EARLY MORNING. CIGS
WILL DIP BRIEFLY INTO MVFR TERRITORY THIS MORNING BEFORE REBOUNDING
DURING THE AFTERNOON. CURRENT MODELS INDICATE A FAIR AMOUNT OF
CLEARING THIS AFTERNOON AND TONIGHT. IF YESTERDAY AFTERNOON WAS ANY
INDICATION...WOULD LEAN TOWARD PROSPECT OF CLEARING BEING RIGHT ON
TRACK.

KSEA...CIGS DROPPING TO BETWEEN 2K AND 3K FT THIS MORNING BEFORE
STARTING TO LIFT BY NOON TODAY...LEADING TO MOSTLY CLEAR CONDITIONS
BY MID AFTERNOON. WINDS LIGHT AND VARIABLE THIS MORNING...BECOMING
NORTH 5-10 KNOTS BY NOON AND REMAINING THERE FOR THE REMAINDER OF
THE TAF FORECAST PERIOD. SMR

&&

.MARINE...LOW LEVEL ONSHORE FLOW PATTERN CONTINUING TODAY
WITH SMALL CRAFT ADVISORIES PERSISTING OVER COASTAL WATERS TODAY AND
THROUGH THE NIGHT TONIGHT WITH SMALL CRAFT WINDS ALSO PRESENT IN THE
CENTRAL AND EASTERN STRAIT DURING THE EARLY MORNING TODAY. THESE
SMALL CRAFT WINDS WILL RETURN TO THE ENTIRE STRAIT LATE THIS
AFTERNOON AND INTO TONIGHT BEFORE DIMINISHING ONCE MORE. CURRENT
ONSHORE FLOW WILL TURN NORTHWESTERLY THIS AFTERNOON AS HIGH PRESSURE
BUILDS INTO SOUTHERN BRITISH COLUMBIA. LOW LEVEL FLOW TURNING
OFFSHORE ON SUNDAY WITH THERMALLY INDUCED TROUGH ALONG THE COAST. A
RETURN TO LOW LEVEL ONSHORE FLOW WILL OCCUR LATER MONDAY INTO
TUESDAY. FELTON/SMR

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE COASTAL WATERS
 AND STRAIT OF JUAN DE FUCA.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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





000
FXUS66 KSEW 301032
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
332 AM PDT SAT APR 30 2016

.SYNOPSIS...HIGH PRESSURE ALOFT WILL BUILD OVER THE REGION THIS
WEEKEND. THIS COMBINED WITH THE LOW LEVEL FLOW BECOMING OFFSHORE
WILL RESULT IN TEMPERATURES CLIMBING ABOVE NORMAL FOR THIS TIME OF
THE YEAR. UNSEASONABLY WARM WEATHER WILL PERSIST ON MONDAY.

&&

.SHORT TERM...
AN UPPER LEVEL RIDGE WILL BUILD OVER THE REGION THIS WEEKEND. THIS
COMBINED WITH THE LOW LEVEL FLOW BECOMING OFFSHORE WILL RESULT IN
ANOTHER PERIOD OF WARM WEATHER. TEMPERATURES TODAY WILL BE ABOVE
NORMAL FOR THIS TIME OF THE YEAR OR GENERALLY FIVE TO DEGREES
WARMER THAN YESTERDAY. A THERMALLY INDUCED AREA OR LOW PRESSURE
ALONG OR JUST OFF THE COAST ON SUNDAY WILL RESULT IN UNSEASONABLE
WARM TEMPERATURES OR TEMPS ONE WOULD EXPECT DURING THE SUMMER.

THE FORECAST FOR MONDAY WILL BE A LITTLE TRICKY. THE SURFACE LOW
OFF THE OREGON COAST IS ANTICIPATED TO SHIFT NORTH DURING THE
DAY. THIS MAY INDUCE A LOW LEVEL SURGE OF MARITIME AIR UP THE
COAST IN THE AFTERNOON...THUS TEMPS ON THE COAST MIGHT BE A LITTLE
COOLER OR A LOT COOLER...DEPENDING ON WHICH MODEL ONE PREFERS. THE
NAM GUIDANCE FOR KHQM...FOR EXAMPLE...HAS A HIGH 68 DEGREES FOR
MONDAY...WHICH WAS ELEVEN DEGREES COOLER THAN ITS FORECAST FOR
SUNDAY. IN CONTRAST...THE GFS HAD A HIGH OF 73 DEGREES FOR KHQM
FOR MONDAY...OR ONLY FIVE DEGREES COOLER THAN ITS FORECAST FOR
SUNDAY. DECIDED TO GO WITH THE GFS SOLUTION FOR NOW DUE TO
UNCERTAINTY IN THE SURFACE FEATURES.

ACROSS THE INTERIOR...EXPECT TEMPS ON MONDAY TO BE A FEW DEGREES
WARMER THAN ON SUNDAY...WITH A FEW SITES HAVING A GOOD CHANCE OF
BREAKING RECORDS FOR THE DATE.

STRONG SOUTHERLY FLOW ALOFT IS EXPECTED TO DEVELOP MONDAY NIGHT.
THIS WILL ALLOW SOME MIDLEVEL MOISTURE AND INSTABILITY TO ADVECT
OVER MAINLY THE SOUTHERN PART OF THE FORECAST AREA FOR A LOW
THREAT OF SHOWERS. IF THE LATEST SREF IS CORRECT...THERE IS ALSO A
POSSIBILITY OF ISOLATED TSTMS MONDAY NIGHT OVER THE CENTRAL
CASCADES.

.LONG TERM...
THE WEATHER PATTERN OVER THE AREA TUESDAY THROUGH FRIDAY OF THE
UPCOMING WEEK WILL BE SOMEWHAT UNSETTLED. AN OMEGA BLOCK WILL
BE OVER THE USA...WITH UPPER LEVEL TROFS OVER THE WEST AND EAST
COASTS. IT APPEARED THAT MUCH OF THE ENERGY WITH THE WEST COAST
TROF WILL IMPACT THE SOUTHWEST USA BUT THERE WILL STILL BE A
THREAT OF SHOWERS OVER THE FORECAST AREA. OTHERWISE...EXPECT
ONSHORE FLOW ACROSS WESTERN WA DURING THIS PERIOD...WITH TEMPS
RETURNING TO NEAR NORMAL.

&&

.AVIATION...UPPER LEVEL RIDGING WILL CONTINUE TO BUILD OFFSHORE
TODAY. NORTHERLY FLOW ALOFT WILL TRANSITION TO BECOME NORTHEASTERLY
TONIGHT. LOW LEVEL ONSHORE FLOW IS EXPECTED TO PERSIST TODAY.

OBS FROM KSEA AND KBFI SHOW THAT CIGS ARE STARTING TO LOWER...WHILE
OBS FROM REMAINING TAF SITES CONTINUE TO SHOW GENERALLY CLEAR
CONDITIONS. IR SATELLITE IMAGERY HOWEVER DOES HINT AT AN INCREASE IN
CLOUD COVER...SO WOULD EXPECT A TRANSITION FROM GENERALLY CLEAR
SKIES TO MORE BROKEN TO OVERCAST CONDITIONS THIS EARLY MORNING. CIGS
WILL DIP BRIEFLY INTO MVFR TERRITORY THIS MORNING BEFORE REBOUNDING
DURING THE AFTERNOON. CURRENT MODELS INDICATE A FAIR AMOUNT OF
CLEARING THIS AFTERNOON AND TONIGHT. IF YESTERDAY AFTERNOON WAS ANY
INDICATION...WOULD LEAN TOWARD PROSPECT OF CLEARING BEING RIGHT ON
TRACK.

KSEA...CIGS DROPPING TO BETWEEN 2K AND 3K FT THIS MORNING BEFORE
STARTING TO LIFT BY NOON TODAY...LEADING TO MOSTLY CLEAR CONDITIONS
BY MID AFTERNOON. WINDS LIGHT AND VARIABLE THIS MORNING...BECOMING
NORTH 5-10 KNOTS BY NOON AND REMAINING THERE FOR THE REMAINDER OF
THE TAF FORECAST PERIOD. SMR

&&

.MARINE...LOW LEVEL ONSHORE FLOW PATTERN CONTINUING TODAY
WITH SMALL CRAFT ADVISORIES PERSISTING OVER COASTAL WATERS TODAY AND
THROUGH THE NIGHT TONIGHT WITH SMALL CRAFT WINDS ALSO PRESENT IN THE
CENTRAL AND EASTERN STRAIT DURING THE EARLY MORNING TODAY. THESE
SMALL CRAFT WINDS WILL RETURN TO THE ENTIRE STRAIT LATE THIS
AFTERNOON AND INTO TONIGHT BEFORE DIMINISHING ONCE MORE. CURRENT
ONSHORE FLOW WILL TURN NORTHWESTERLY THIS AFTERNOON AS HIGH PRESSURE
BUILDS INTO SOUTHERN BRITISH COLUMBIA. LOW LEVEL FLOW TURNING
OFFSHORE ON SUNDAY WITH THERMALLY INDUCED TROUGH ALONG THE COAST. A
RETURN TO LOW LEVEL ONSHORE FLOW WILL OCCUR LATER MONDAY INTO
TUESDAY. FELTON/SMR

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORIES ARE IN EFFECT FOR THE COASTAL WATERS
 AND STRAIT OF JUAN DE FUCA.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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





000
FXUS66 KSEW 300404
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PDT FRI APR 29 2016

.SYNOPSIS...A STRONG UPPER RIDGE WILL BRING DRY WARMER WEATHER
SATURDAY THROUGH MONDAY. A CHANCE OF SHOWERS WILL RETURN TUESDAY
THROUGH THURSDAY OF NEXT WEEK...WITH MOIST SOUTHERLY FLOW ALOFT
AND LOW LEVEL ONSHORE FLOW.

&&

.SHORT TERM...SHOWERS ARE WINDING DOWN TONIGHT AS AN UPPER LEVEL
TROUGH MOVES EAST OF THE CASCADES. KATX SHOWS ONLY ISOLATED SHOWERS
IN THURSTON...PIERCE AND IN THE CENTRAL CASCADES. THESE SHOWERS
SHOULD BE OVER BY MIDNIGHT.

AN UPPER LEVEL RIDGE WILL NUDGE INLAND ON SATURDAY FOR DRY AND MILD
WEATHER ACROSS WESTERN WA. NORTHERLY FLOW WILL SCOUR OUT THE MORNING
LOW CLOUDS FOR MOSTLY SUNNY SKIES. HIGH TEMPS WILL BE IN THE LOW TO
MID 60S...A FEW DEGREES ABOVE NORMAL.

THE UPPER LEVEL RIDGE WILL REMAIN OVER THE PAC NW ON SUNDAY FOR
ANOTHER DRY DAY. OFFSHORE FLOW WILL INCREASE WITH A THERMAL TROUGH
FORMING ALONG THE COAST. HIGHS WILL BE IN THE 70S TO LOWER 80S ALONG
THE COAST AND INTERIOR. IT WILL BE SLIGHTLY COOLER IN THE STRAIT OF
JUAN DE FUCA AND SAN JUANS WITH TEMPS MAINLY IN THE 60S.

MONDAY WILL BE THE WARMEST DAY OF THIS STRETCH WITH THE RIDGE STILL
OVERHEAD AND THE FLOW STILL OFFSHORE. EXPECT HIGHS IN THE LOW TO MID
80S IN THE INTERIOR. 33

.LONG TERM...PREVIOUS DISCUSSION...AN UPPER TROUGH WILL APPROACH FROM
THE WEST ON TUESDAY WITH INCREASINGLY MOIST SOUTHERLY FLOW ALOFT FOR
A CHANCE OF SHOWERS. INCREASING LOW LEVEL ONSHORE FLOW WILL COOL
HIGHS ON THE ORDER OF 10 DEGREES FROM MONDAY.

THIS GENERAL PATTERN WILL CONTINUE ON WEDNESDAY...MOIST SOUTHERLY
FLOW ALOFT FOR A CHANCE OF SHOWERS. THE UPPER TROUGH OFFSHORE WILL
TURN INTO A CUTOFF UPPER LOW WELL TO THE SOUTH ON THURSDAY AND
FRIDAY. THIS WILL KEEP MOST OF THE SHOWER THREAT TO THE SOUTH BUT
SOME ACTIVITY COULD CERTAINLY SNEAK UP FROM THE SOUTH OR EAST. THE
BEST CHANCES WILL BE OVER THE CASCADES. SCHNEIDER

&&

.AVIATION...UPPER LEVEL TROUGH OVER EASTERN WASHINGTON
SLOWLY MOVING EAST WITH UPPER LEVEL RIDGE BUILDING OFFSHORE. LIGHT
FLOW ALOFT BECOMING NORTHWESTERLY. LOW LEVEL ONSHORE FLOW CONTINUING
INTO SATURDAY.

CURRENT SKY CONDITIONS A BIT MORE OPTIMISTIC THAN MODELS
SUGGEST...WITH MAINLY SCATTERED CLOUDS OVER MOST LOCATIONS AT
HEIGHTS RANGING FROM 3500 FT TO 6000 FT. KOLM SEEMS TO BE AN
EXCEPTION AT THIS TIME...REPORTING BKN TO OVC CONDITIONS...BUT CIGS
STILL FALLING WITHIN THE ABOVE RANGE...THUS VFR CONDITIONS. WITH
LIGHT ONSHORE FLOW CONTINUING...EXPECT CIGS TO LOWER TO NEAR 2000
FEET 10Z-18Z SATURDAY...BUT WILL SCATTER OUT BY MIDDAY SATURDAY.

KSEA...SCATTERED CLOUDS AT 3.5K FT AND 6K FT THIS EVENING. CLOUDS
EXPECTED TO INCREASE OVERNIGHT WITH CIGS FALLING TO NEAR 2000 FEET
AROUND 12Z SATURDAY. GENERALLY LIGHT AND VARIABLE WINDS THIS EVENING
SHIFTING SOUTH TO SOUTHEAST AFTER 06Z. WINDS WILL RETURN TO
NORTHERLY BY SATURDAY AFTERNOON WITH SPEEDS 5-10 KTS. FELTON/SMR

&&

.MARINE...LOW LEVEL ONSHORE FLOW PATTERN CONTINUING INTO SATURDAY
WITH SMALL CRAFT ADVISORIES OVER THE COASTAL WATERS AND BORDERLINE
GALES IN THE STRAIT OF JUAN DE FUCA. WINDS IN THE STRAIT SEEM TO BE
DIMINISHING BELOW GALE CRITERIA...SO WILL ALLOW GALES TO EXPIRE AT
11 PM PDT TONIGHT. ONSHORE FLOW TURNS NORTHWESTERLY ON SATURDAY WITH
HIGH PRESSURE BUILDING INTO SOUTHERN BRITISH COLUMBIA. LOW LEVEL
FLOW TURNING OFFSHORE ON SUNDAY WITH THERMALLY INDUCED TROUGH ALONG
THE COAST. A RETURN TO LOW LEVEL ONSHORE FLOW WILL OCCUR LATER
MONDAY INTO TUESDAY.
FELTON

&&

.SEW WATCHES/WARNINGS/ADVISORIES...

WA...NONE.
PZ...SMALL CRAFT ADVISORIES COAST AND WEST ENTRANCE STRAIT OF JUAN
     DE FUCA.

     GALE WARNING CENTRAL AND EAST ENTRANCE STRAIT OF JUAN DE FUCA.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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000
FXUS66 KSEW 292248
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
348 PM PDT FRI APR 29 2016

.SYNOPSIS...A STRONG UPPER RIDGE WILL BRING DRY WARMER WEATHER
SATURDAY THROUGH MONDAY. A CHANCE OF SHOWERS WILL RETURN TUESDAY
THROUGH THURSDAY OF NEXT WEEK...WITH MOIST SOUTHERLY FLOW ALOFT
AND LOW LEVEL ONSHORE FLOW.

&&

.SHORT TERM...SHOWERS WILL QUICKLY END THIS EVENING AS A WEATHER
SYSTEM DEPARTS. HIGH PRESSURE ALOFT WILL BUILD OVER THE PACIFIC
NORTHWEST SATURDAY WITH NORTHERLY LOW LEVEL FLOW DEVELOPING. SOME
CLOUDS WILL LIKELY LINGER IN THE MORNING...THEN SKIES SHOULD
BECOME MOSTLY SUNNY. HIGHS WILL WARM INTO THE 60S.

THE UPPER RIDGE WILL STRENGTHEN OVER THE AREA ON SUNDAY WITH
INCREASING LOW LEVEL OFFSHORE FLOW. THIS WILL BRING ANOTHER SUNNY
DAY WITH HIGHS WARMING WELL INTO THE 70S OR EVEN LOWER 80S IN THE
USUAL WARMER SPOTS.

MONDAY WILL BE THE WARMEST DAY OF THE WEEK. THE COAST WILL SEE A
LITTLE COOLING AS OFFSHORE FLOW WEAKENS BUT INLAND SHOULD BE A
COUPLE DEGREES WARMER. THE GFS HAS BEEN HINTING AS POSSIBLE
ISOLATED CONVECTION LATE IN THE DAY AS SOUTHERLY FLOW ALOFT
DEVELOPS BUT THE FORECAST IS DRY FOR NOW WHICH IS MORE IN LINE
WITH THE ECMWF. SCHNEIDER

.LONG TERM...AN UPPER TROUGH WILL APPROACH FROM THE WEST ON
TUESDAY WITH INCREASINGLY MOIST SOUTHERLY FLOW ALOFT FOR A CHANCE
OF SHOWERS. INCREASING LOW LEVEL ONSHORE FLOW WILL COOL HIGHS ON
THE ORDER OF 10 DEGREES FROM MONDAY.

THIS GENERAL PATTERN WILL CONTINUE ON WEDNESDAY...MOIST SOUTHERLY
FLOW ALOFT FOR A CHANCE OF SHOWERS. THE UPPER TROUGH OFFSHORE WILL
TURN INTO A CUTOFF UPPER LOW WELL TO THE SOUTH ON THURSDAY AND
FRIDAY. THIS WILL KEEP MOST OF THE SHOWER THREAT TO THE SOUTH BUT
SOME ACTIVITY COULD CERTAINLY SNEAK UP FROM THE SOUTH OR EAST. THE
BEST CHANCES WILL BE OVER THE CASCADES. SCHNEIDER

&&

.AVIATION...UPPER LEVEL TROUGH OVER EASTERN WASHINGTON SLOWLY
MOVING EAST WITH UPPER LEVEL RIDGE BUILDING OFFSHORE. LIGHT FLOW
ALOFT BECOMING NORTHWESTERLY. LOW LEVEL ONSHORE FLOW CONTINUING
INTO SATURDAY.

SCATTERED TO BROKEN LAYER NEAR 3500 FEET WITH ANOTHER SCATTERED TO
BROKEN LAYER NEAR 6000 FEET. WITH LIGHT ONSHORE FLOW CEILINGS
LOWERING TO NEAR 2000 FEET 10Z-18Z SATURDAY. CLOUDS SCATTERING OUT
MIDDAY SATURDAY.

KSEA...CEILINGS AROUND 3000 FEET LIFTING TO 5000-6000 FEET THIS
EVENING. CEILINGS LOWER BACK DOWN TO NEAR 2000 FEET AROUND 12Z
SATURDAY. LIGHT NORTHERLY WINDS BECOMING VARIABLE AFTER 06Z.
FELTON

&&

.MARINE...LOW LEVEL ONSHORE FLOW PATTERN CONTINUING INTO SATURDAY
WITH SMALL CRAFT ADVISORIES OVER THE COASTAL WATERS AND IN THE
STRAIT OF JUAN DE FUCA. ONSHORE FLOW TURNS NORTHWESTERLY ON
SATURDAY WITH HIGH PRESSURE BUILDING INTO SOUTHERN BRITISH
COLUMBIA. LOW LEVEL FLOW TURNING OFFSHORE ON SUNDAY WITH THERMALLY
INDUCED TROUGH ALONG THE COAST. A RETURN TO LOW LEVEL ONSHORE FLOW
WILL OCCUR LATER MONDAY INTO TUESDAY. FELTON

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 5 PM PDT SATURDAY FOR COASTAL WATERS
     FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL
     WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM-
     COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER 10
     TO 60 NM.

     SMALL CRAFT ADVISORY UNTIL 5 AM PDT SATURDAY FOR CENTRAL U.S.
     WATERS STRAIT OF JUAN DE FUCA-COASTAL WATERS FROM CAPE
     FLATTERY TO JAMES ISLAND OUT 10 NM-COASTAL WATERS FROM
     JAMES ISLAND TO POINT GRENVILLE OUT 10 NM-COASTAL WATERS
     FROM POINT GRENVILLE TO CAPE SHOALWATER OUT 10 NM-EAST
     ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA-WEST ENTRANCE
     U.S. WATERS STRAIT OF JUAN DE FUCA.

     SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO NOON PDT SATURDAY
     FOR NORTHERN INLAND WATERS INCLUDING THE SAN JUAN ISLANDS.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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000
FXUS66 KSEW 291613
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
913 AM PDT FRI APR 29 2016

.SYNOPSIS...A FRONT AND ITS UPPER TROUGH WILL MOVE THROUGH WESTERN
WASHINGTON TODAY FOR OCCASIONAL SHOWERS OVER MOST OF THE AREA. A
STRONG UPPER RIDGE WILL BRING DRY WARMER WEATHER SATURDAY THROUGH
MONDAY. A CHANCE OF SHOWERS WILL RETURN TUESDAY THROUGH THURSDAY
OF NEXT WEEK...WITH MOIST SOUTHERLY FLOW ALOFT AND LOW LEVEL
ONSHORE FLOW.

&&

.SHORT TERM...AN UPPER TROUGH AND A WEAK FRONT WILL BRING SHOWERS
TODAY. THIS WEATHER SYSTEM WILL RAPIDLY EXIT THE AREA TONIGHT
WITH SHOWERS ENDING IN THE EVENING. HIGHS TODAY WILL BE MAINLY
IN THE MID TO UPPER 50S WHICH IS A FEW DEGREES BELOW NORMAL.

HIGH PRESSURE ALOFT WILL BUILD OVER THE PACIFIC NORTHWEST
SATURDAY WITH NORTHERLY LOW LEVEL FLOW DEVELOPING. SOME CLOUDS
WILL LIKELY LINGER IN THE MORNING...THEN SKIES SHOULD BECOME
MOSTLY SUNNY. HIGHS WILL WARM INTO THE 60S.

THE UPPER RIDGE WILL STRENGTHEN OVER THE AREA ON SUNDAY WITH
INCREASING LOW LEVEL OFFSHORE FLOW. THIS WILL BRING ANOTHER SUNNY
DAY WITH HIGHS WARMING WELL INTO THE 70S OR EVEN LOWER 80S IN THE
USUAL WARMER SPOTS. SCHNEIDER

.LONG TERM...PREVIOUS DISCUSSION...THE UPPER RIDGE WILL MOVE
FURTHER EAST ON MONDAY...AND THE AIR MASS WILL WARM A BIT MORE AS
SOUTHERLY FLOW ALOFT DEVELOPS. IT IS CONCEIVABLE THAT SOME MID
LEVEL MOISTURE WILL ACCOMPANY WEAK INSTABILITY OVER THE MOUNTAINS
TO PRODUCE ISOLATED SHOWERS BY LATE MONDAY. THE MODELS HAVE NOT
BEEN CONSISTENT WITH THAT IDEA THOUGH...AND IN COORDINATION WITH
SURROUNDING OFFICES WE WILL STAY WITH A DRY FORECAST FOR NOW.
THERE IS A BETTER CHANCE OF SHOWERS DEVELOPING TUESDAY ALONG WITH
INCREASING ONSHORE FLOW. MOIST SOUTHERLY FLOW ALOFT...WEAK
INSTABILITY...AND LOW LEVEL ONSHORE FLOW WILL KEEP A CHANCE OF
SHOWERS IN THE FORECAST WEDNESDAY AND THURSDAY AS WELL. MCDONNAL

&&

.AVIATION...UPPER LEVEL TROUGH OVER WESTERN WASHINGTON THIS
MORNING WILL SHIFT EAST THIS AFTERNOON. LIGHT FLOW ALOFT BECOMING
NORTHWESTERLY. LOW LEVEL ONSHORE FLOW CONTINUING INTO SATURDAY.

CEILINGS MOSTLY IN THE 1500-2500 FOOT RANGE INTO THE AFTERNOON
HOURS. SOME IMPROVEMENT MID TO LATE AFTERNOON WITH THE CEILINGS
LIFTING TO 3000-4000 FEET. CONVERGENCE OVER NORTH KING AND SNOHOMISH
COUNTY WILL KEEP MVFR CEILINGS BETWEEN KBFI AND KPAE INTO THE
EVENING HOURS.

KSEA...CEILINGS AROUND 1500 FEET INTO THE AFTERNOON HOURS. SOME
IMPROVEMENT LATE AFTERNOON UP TO AROUND 3000 FEET. LIGHT SOUTH
WINDS BECOMING NORTHERLY LATE THIS AFTERNOON INTO THE EVENING HOURS.
FELTON

&&

.MARINE...LOW LEVEL ONSHORE FLOW PATTERN CONTINUING INTO SATURDAY
WITH SMALL CRAFT ADVISORIES OVER THE COASTAL WATERS...IN THE STRAIT
OF JUAN DE FUCA AND THE NORTHERN INLAND WATERS. ONSHORE FLOW TURNS
NORTHWESTERLY ON SATURDAY WITH THE LOW LEVEL FLOW TURNING OFFSHORE
ON SUNDAY. A RETURN TO LOW LEVEL ONSHORE FLOW WILL OCCUR LATER MONDAY
INTO TUESDAY. FELTON

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 5 PM PDT SATURDAY FOR COASTAL WATERS
     FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL
     WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM-
     COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER 10
     TO 60 NM.

     SMALL CRAFT ADVISORY UNTIL 5 AM PDT SATURDAY FOR COASTAL WATERS
     FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-COASTAL WATERS
     FROM JAMES ISLAND TO POINT GRENVILLE OUT 10 NM-COASTAL
     WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER OUT 10 NM-
     WEST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.

     SMALL CRAFT ADVISORY UNTIL 5 AM PDT SATURDAY FOR CENTRAL U.S.
     WATERS STRAIT OF JUAN DE FUCA-EAST ENTRANCE U.S. WATERS
     STRAIT OF JUAN DE FUCA.

     SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO NOON PDT SATURDAY
     FOR NORTHERN INLAND WATERS INCLUDING THE SAN JUAN ISLANDS.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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





000
FXUS66 KSEW 291613
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
913 AM PDT FRI APR 29 2016

.SYNOPSIS...A FRONT AND ITS UPPER TROUGH WILL MOVE THROUGH WESTERN
WASHINGTON TODAY FOR OCCASIONAL SHOWERS OVER MOST OF THE AREA. A
STRONG UPPER RIDGE WILL BRING DRY WARMER WEATHER SATURDAY THROUGH
MONDAY. A CHANCE OF SHOWERS WILL RETURN TUESDAY THROUGH THURSDAY
OF NEXT WEEK...WITH MOIST SOUTHERLY FLOW ALOFT AND LOW LEVEL
ONSHORE FLOW.

&&

.SHORT TERM...AN UPPER TROUGH AND A WEAK FRONT WILL BRING SHOWERS
TODAY. THIS WEATHER SYSTEM WILL RAPIDLY EXIT THE AREA TONIGHT
WITH SHOWERS ENDING IN THE EVENING. HIGHS TODAY WILL BE MAINLY
IN THE MID TO UPPER 50S WHICH IS A FEW DEGREES BELOW NORMAL.

HIGH PRESSURE ALOFT WILL BUILD OVER THE PACIFIC NORTHWEST
SATURDAY WITH NORTHERLY LOW LEVEL FLOW DEVELOPING. SOME CLOUDS
WILL LIKELY LINGER IN THE MORNING...THEN SKIES SHOULD BECOME
MOSTLY SUNNY. HIGHS WILL WARM INTO THE 60S.

THE UPPER RIDGE WILL STRENGTHEN OVER THE AREA ON SUNDAY WITH
INCREASING LOW LEVEL OFFSHORE FLOW. THIS WILL BRING ANOTHER SUNNY
DAY WITH HIGHS WARMING WELL INTO THE 70S OR EVEN LOWER 80S IN THE
USUAL WARMER SPOTS. SCHNEIDER

.LONG TERM...PREVIOUS DISCUSSION...THE UPPER RIDGE WILL MOVE
FURTHER EAST ON MONDAY...AND THE AIR MASS WILL WARM A BIT MORE AS
SOUTHERLY FLOW ALOFT DEVELOPS. IT IS CONCEIVABLE THAT SOME MID
LEVEL MOISTURE WILL ACCOMPANY WEAK INSTABILITY OVER THE MOUNTAINS
TO PRODUCE ISOLATED SHOWERS BY LATE MONDAY. THE MODELS HAVE NOT
BEEN CONSISTENT WITH THAT IDEA THOUGH...AND IN COORDINATION WITH
SURROUNDING OFFICES WE WILL STAY WITH A DRY FORECAST FOR NOW.
THERE IS A BETTER CHANCE OF SHOWERS DEVELOPING TUESDAY ALONG WITH
INCREASING ONSHORE FLOW. MOIST SOUTHERLY FLOW ALOFT...WEAK
INSTABILITY...AND LOW LEVEL ONSHORE FLOW WILL KEEP A CHANCE OF
SHOWERS IN THE FORECAST WEDNESDAY AND THURSDAY AS WELL. MCDONNAL

&&

.AVIATION...UPPER LEVEL TROUGH OVER WESTERN WASHINGTON THIS
MORNING WILL SHIFT EAST THIS AFTERNOON. LIGHT FLOW ALOFT BECOMING
NORTHWESTERLY. LOW LEVEL ONSHORE FLOW CONTINUING INTO SATURDAY.

CEILINGS MOSTLY IN THE 1500-2500 FOOT RANGE INTO THE AFTERNOON
HOURS. SOME IMPROVEMENT MID TO LATE AFTERNOON WITH THE CEILINGS
LIFTING TO 3000-4000 FEET. CONVERGENCE OVER NORTH KING AND SNOHOMISH
COUNTY WILL KEEP MVFR CEILINGS BETWEEN KBFI AND KPAE INTO THE
EVENING HOURS.

KSEA...CEILINGS AROUND 1500 FEET INTO THE AFTERNOON HOURS. SOME
IMPROVEMENT LATE AFTERNOON UP TO AROUND 3000 FEET. LIGHT SOUTH
WINDS BECOMING NORTHERLY LATE THIS AFTERNOON INTO THE EVENING HOURS.
FELTON

&&

.MARINE...LOW LEVEL ONSHORE FLOW PATTERN CONTINUING INTO SATURDAY
WITH SMALL CRAFT ADVISORIES OVER THE COASTAL WATERS...IN THE STRAIT
OF JUAN DE FUCA AND THE NORTHERN INLAND WATERS. ONSHORE FLOW TURNS
NORTHWESTERLY ON SATURDAY WITH THE LOW LEVEL FLOW TURNING OFFSHORE
ON SUNDAY. A RETURN TO LOW LEVEL ONSHORE FLOW WILL OCCUR LATER MONDAY
INTO TUESDAY. FELTON

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY UNTIL 5 PM PDT SATURDAY FOR COASTAL WATERS
     FROM CAPE FLATTERY TO JAMES ISLAND 10 TO 60 NM-COASTAL
     WATERS FROM JAMES ISLAND TO POINT GRENVILLE 10 TO 60 NM-
     COASTAL WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER 10
     TO 60 NM.

     SMALL CRAFT ADVISORY UNTIL 5 AM PDT SATURDAY FOR COASTAL WATERS
     FROM CAPE FLATTERY TO JAMES ISLAND OUT 10 NM-COASTAL WATERS
     FROM JAMES ISLAND TO POINT GRENVILLE OUT 10 NM-COASTAL
     WATERS FROM POINT GRENVILLE TO CAPE SHOALWATER OUT 10 NM-
     WEST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.

     SMALL CRAFT ADVISORY UNTIL 5 AM PDT SATURDAY FOR CENTRAL U.S.
     WATERS STRAIT OF JUAN DE FUCA-EAST ENTRANCE U.S. WATERS
     STRAIT OF JUAN DE FUCA.

     SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO NOON PDT SATURDAY
     FOR NORTHERN INLAND WATERS INCLUDING THE SAN JUAN ISLANDS.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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





000
FXUS66 KSEW 291018
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
318 AM PDT FRI APR 29 2016

.SYNOPSIS...A FRONT AND ITS UPPER TROUGH WILL MOVE THROUGH WESTERN
WASHINGTON TODAY FOR OCCASIONAL SHOWERS OVER MOST OF THE AREA. A
STRONG UPPER RIDGE WILL BRING DRY WARMER WEATHER SATURDAY THROUGH
MONDAY. A CHANCE OF SHOWERS WILL RETURN TUESDAY THROUGH THURSDAY
OF NEXT WEEK...WITH MOIST SOUTHERLY FLOW ALOFT AND LOW LEVEL
ONSHORE FLOW.

&&

.SHORT TERM...A WEAK COLD FRONT AND UPPER TROUGH ARE APPROACHING
THE PACIFIC NORTHWEST COAST EARLY THIS MORNING. AT 3 AM THE RADAR
ON THE WASHINGTON COAST WAS JUST STARTING TO SHOW PRECIPITATION
OVER THE COASTAL WATERS. THERE ARE ALSO SOME LIGHT SPOTTY SHOWERS
ALONG THE WEST SLOPES OF THE CASCADES AND IN THE WEAK CONVERGENCE
ZONE OVER SNOHOMISH COUNTY...BUT OTHERWISE WESTERN WASHINGTON WAS
DRY OVERNIGHT. TEMPERATURES WERE IN THE MID 40S TO LOWER 50S.

THE SYSTEM WILL MOVE ACROSS WESTERN WASHINGTON THIS MORNING...
AND MOIST ONSHORE LOW LEVEL FLOW WILL CONTINUE BEHIND THE FRONT
THIS AFTERNOON. MEASURABLE PRECIPITATION SHOULD BE WIDESPREAD...
BUT IT WON`T AMOUNT TO MUCH -- ROUGHLY 0.10 TO 0.20 INCH IN THE
CONVERGENCE ZONE AND MOSTLY LESS THAN 0.10 INCH ELSEWHERE IN THE
LOWLANDS. A BIT MORE WILL FALL IN THE CASCADES...WITH THE SNOW
LEVEL AROUND 4500 FT AND 1 TO 3 INCHES OF SNOW ABOVE THAT.

A STRONG UPPER RIDGE WILL BEGIN BUILDING OFFSHORE TONIGHT...JUST
OUTSIDE OF 130W. DRY NORTHERLY FLOW ALOFT WILL DEVELOP QUICKLY
OVER WESTERN WASHINGTON...SO SHOWERS WILL BECOME MAINLY LIMITED TO
THE CASCADES AND SOUTH INTERIOR IN THE EVENING AND THEN END
OVERNIGHT.

THE UPPER RIDGE WILL SHIFT SLOWLY EAST OVER THE AREA THIS WEEKEND.
THE AIR MASS WILL WARM...WITH 850 MB TEMPERATURES OVER WESTERN
WASHINGTON REACHING AROUND +6C ON SATURDAY AND +12C ON SUNDAY. IN
ADDITION OFFSHORE FLOW WILL DEVELOP ON SUNDAY AS A THERMAL TROUGH
EXTENDS NORTHWARD ALONG THE PACIFIC NORTHWEST COAST FROM NORTHERN
CALIFORNIA. HIGHS SHOULD BE IN THE 60S TO LOWER 70S SATURDAY AND
MOSTLY IN THE 70S TO LOWER 80S SUNDAY. MCDONNAL

.LONG TERM...THE UPPER RIDGE WILL MOVE FURTHER EAST ON MONDAY...
AND THE AIR MASS WILL WARM A BIT MORE AS SOUTHERLY FLOW ALOFT
DEVELOPS. IT IS CONCEIVABLE THAT SOME MID LEVEL MOISTURE WILL
ACCOMPANY WEAK INSTABILITY OVER THE MOUNTAINS TO PRODUCE ISOLATED
SHOWERS BY LATE MONDAY. THE MODELS HAVE NOT BEEN CONSISTENT WITH
THAT IDEA THOUGH...AND IN COORDINATION WITH SURROUNDING OFFICES WE
WILL STAY WITH A DRY FORECAST FOR NOW. THERE IS A BETTER CHANCE OF
SHOWERS DEVELOPING TUESDAY ALONG WITH INCREASING ONSHORE FLOW.
MOIST SOUTHERLY FLOW ALOFT...WEAK INSTABILITY...AND LOW LEVEL
ONSHORE FLOW WILL KEEP A CHANCE OF SHOWERS IN THE FORECAST
WEDNESDAY AND THURSDAY AS WELL. MCDONNAL

&&

.AVIATION...AN UPPER TROUGH AXIS WILL PASS WRN WA THIS MORNING.
AIR MASS HAS ALREADY STARTED TO MOISTEN...WITH INSTABILITY
INCREASING AS TROUGH AXIS PASSES THROUGH. SHOWERS AND FAIRLY
WIDESPREAD IFR CIGS EXPECTED BY MID TO LATE MORNING. KPAE IS ALREADY
SEEING SUCH CONDITIONS THANKS TO A PSCZ THAT DEVELOPED DURING THE
OVERNIGHT HOURS. THE RISK FOR SHOWERS CONTINUES TO LOOK LIKE A
GENERALLY NARROW WINDOW WITH THE THREAT ENDING AND GRADUAL CLEARING
EXPECTED THIS AFTERNOON AND EVENING FROM WEST TO EAST. LIGHT NW
UPPER LEVEL FLOW TODAY...SHIFTING TO THE NORTH AND STRENGTHENING
TONIGHT. SMR

KSEA...INCREASING CLOUDS WEST OF PUGET SOUND AT THE TIME OF THIS
WRITING WILL LIKELY SPREAD OVER KSEA BY BETWEEN 10Z AND
11Z...BRINGING CIGS DOWN TO IFR IN ABOUT THE 1-2K FT RANGE. MODEL
TIMING OF SHOWERS REMAINS CONSISTENT WITH ACTIVITY KICKING OFF BY
MID MORNING AND WRAPPING UP BY MID AFTERNOON. CIGS ARE EXPECTED TO
LIFT TO VFR THIS AFTERNOON AND EVENING...BUT LOOKS LIKE SOME
CLOUDINESS WILL LINGER INTO THE OVERNIGHT HOURS. SMR

&&

.MARINE...A FRONT WILL PASS EASTWARD ACROSS THE WATERS THIS EARLY
MORNING...ENHANCING ONSHORE FLOW INTO THIS EVENING. SMALL CRAFT
ADVISORIES REMAIN IN PLACE FOR CENTRAL AND EASTERN STRAIT AND HAVE
BEEN EXTENDED INTO LATE TONIGHT. WHILE THERE MAY BE A BRIEF PERIOD
WHERE WINDS WILL FALL BELOW ADVISORY CRITERIA...DID NOT WANT TO
SPLIT HAIRS AS WINDS WILL PICK UP AGAIN AS FRONT MOVES THROUGH. WITH
THAT INCREASE IN WINDS...WATERS IMPACTED BY SMALL CRAFT ADVISORY
WIND SPEEDS WILL INCLUDED COASTAL WATERS...NORTHERN INLAND
WATERS...AND THE WEST ENTRANCE. THUS ALL HAVE THEIR OWN ADVISORIES
IN PLACE WITH START AND END TIMES STAGGERED ACCORDINGLY. ADVISORIES
FOR COASTAL WATERS MAY NEED TO BE EXTENDED INTO SUNDAY...BUT THAT IS
BEST LEFT TO FUTURE FORECASTS.

A TURN TO NORTHERLY ONSHORE FLOW IS EXPECTED ON SATURDAY.
NORTHERLY OFFSHORE FLOW IS EXPECTED ON SUNDAY. NORTHERLIES COULD
REACH SMALL CRAFT STRENGTH IN PUGET SOUND ON SUNDAY PM. HANER/SMR

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 5 PM PDT
     SATURDAY FOR COASTAL WATERS FROM CAPE FLATTERY TO JAMES
     ISLAND 10 TO 60 NM-COASTAL WATERS FROM JAMES ISLAND TO
     POINT GRENVILLE 10 TO 60 NM-COASTAL WATERS FROM POINT
     GRENVILLE TO CAPE SHOALWATER 10 TO 60 NM.

     SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 5 AM PDT
     SATURDAY FOR COASTAL WATERS FROM CAPE FLATTERY TO JAMES
     ISLAND OUT 10 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT
     GRENVILLE OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO
     CAPE SHOALWATER OUT 10 NM-WEST ENTRANCE U.S. WATERS STRAIT
     OF JUAN DE FUCA.

     SMALL CRAFT ADVISORY UNTIL 5 AM PDT SATURDAY FOR CENTRAL U.S.
     WATERS STRAIT OF JUAN DE FUCA-EAST ENTRANCE U.S. WATERS
     STRAIT OF JUAN DE FUCA.

     SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO NOON PDT SATURDAY
     FOR NORTHERN INLAND WATERS INCLUDING THE SAN JUAN ISLANDS.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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





000
FXUS66 KSEW 291018
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
318 AM PDT FRI APR 29 2016

.SYNOPSIS...A FRONT AND ITS UPPER TROUGH WILL MOVE THROUGH WESTERN
WASHINGTON TODAY FOR OCCASIONAL SHOWERS OVER MOST OF THE AREA. A
STRONG UPPER RIDGE WILL BRING DRY WARMER WEATHER SATURDAY THROUGH
MONDAY. A CHANCE OF SHOWERS WILL RETURN TUESDAY THROUGH THURSDAY
OF NEXT WEEK...WITH MOIST SOUTHERLY FLOW ALOFT AND LOW LEVEL
ONSHORE FLOW.

&&

.SHORT TERM...A WEAK COLD FRONT AND UPPER TROUGH ARE APPROACHING
THE PACIFIC NORTHWEST COAST EARLY THIS MORNING. AT 3 AM THE RADAR
ON THE WASHINGTON COAST WAS JUST STARTING TO SHOW PRECIPITATION
OVER THE COASTAL WATERS. THERE ARE ALSO SOME LIGHT SPOTTY SHOWERS
ALONG THE WEST SLOPES OF THE CASCADES AND IN THE WEAK CONVERGENCE
ZONE OVER SNOHOMISH COUNTY...BUT OTHERWISE WESTERN WASHINGTON WAS
DRY OVERNIGHT. TEMPERATURES WERE IN THE MID 40S TO LOWER 50S.

THE SYSTEM WILL MOVE ACROSS WESTERN WASHINGTON THIS MORNING...
AND MOIST ONSHORE LOW LEVEL FLOW WILL CONTINUE BEHIND THE FRONT
THIS AFTERNOON. MEASURABLE PRECIPITATION SHOULD BE WIDESPREAD...
BUT IT WON`T AMOUNT TO MUCH -- ROUGHLY 0.10 TO 0.20 INCH IN THE
CONVERGENCE ZONE AND MOSTLY LESS THAN 0.10 INCH ELSEWHERE IN THE
LOWLANDS. A BIT MORE WILL FALL IN THE CASCADES...WITH THE SNOW
LEVEL AROUND 4500 FT AND 1 TO 3 INCHES OF SNOW ABOVE THAT.

A STRONG UPPER RIDGE WILL BEGIN BUILDING OFFSHORE TONIGHT...JUST
OUTSIDE OF 130W. DRY NORTHERLY FLOW ALOFT WILL DEVELOP QUICKLY
OVER WESTERN WASHINGTON...SO SHOWERS WILL BECOME MAINLY LIMITED TO
THE CASCADES AND SOUTH INTERIOR IN THE EVENING AND THEN END
OVERNIGHT.

THE UPPER RIDGE WILL SHIFT SLOWLY EAST OVER THE AREA THIS WEEKEND.
THE AIR MASS WILL WARM...WITH 850 MB TEMPERATURES OVER WESTERN
WASHINGTON REACHING AROUND +6C ON SATURDAY AND +12C ON SUNDAY. IN
ADDITION OFFSHORE FLOW WILL DEVELOP ON SUNDAY AS A THERMAL TROUGH
EXTENDS NORTHWARD ALONG THE PACIFIC NORTHWEST COAST FROM NORTHERN
CALIFORNIA. HIGHS SHOULD BE IN THE 60S TO LOWER 70S SATURDAY AND
MOSTLY IN THE 70S TO LOWER 80S SUNDAY. MCDONNAL

.LONG TERM...THE UPPER RIDGE WILL MOVE FURTHER EAST ON MONDAY...
AND THE AIR MASS WILL WARM A BIT MORE AS SOUTHERLY FLOW ALOFT
DEVELOPS. IT IS CONCEIVABLE THAT SOME MID LEVEL MOISTURE WILL
ACCOMPANY WEAK INSTABILITY OVER THE MOUNTAINS TO PRODUCE ISOLATED
SHOWERS BY LATE MONDAY. THE MODELS HAVE NOT BEEN CONSISTENT WITH
THAT IDEA THOUGH...AND IN COORDINATION WITH SURROUNDING OFFICES WE
WILL STAY WITH A DRY FORECAST FOR NOW. THERE IS A BETTER CHANCE OF
SHOWERS DEVELOPING TUESDAY ALONG WITH INCREASING ONSHORE FLOW.
MOIST SOUTHERLY FLOW ALOFT...WEAK INSTABILITY...AND LOW LEVEL
ONSHORE FLOW WILL KEEP A CHANCE OF SHOWERS IN THE FORECAST
WEDNESDAY AND THURSDAY AS WELL. MCDONNAL

&&

.AVIATION...AN UPPER TROUGH AXIS WILL PASS WRN WA THIS MORNING.
AIR MASS HAS ALREADY STARTED TO MOISTEN...WITH INSTABILITY
INCREASING AS TROUGH AXIS PASSES THROUGH. SHOWERS AND FAIRLY
WIDESPREAD IFR CIGS EXPECTED BY MID TO LATE MORNING. KPAE IS ALREADY
SEEING SUCH CONDITIONS THANKS TO A PSCZ THAT DEVELOPED DURING THE
OVERNIGHT HOURS. THE RISK FOR SHOWERS CONTINUES TO LOOK LIKE A
GENERALLY NARROW WINDOW WITH THE THREAT ENDING AND GRADUAL CLEARING
EXPECTED THIS AFTERNOON AND EVENING FROM WEST TO EAST. LIGHT NW
UPPER LEVEL FLOW TODAY...SHIFTING TO THE NORTH AND STRENGTHENING
TONIGHT. SMR

KSEA...INCREASING CLOUDS WEST OF PUGET SOUND AT THE TIME OF THIS
WRITING WILL LIKELY SPREAD OVER KSEA BY BETWEEN 10Z AND
11Z...BRINGING CIGS DOWN TO IFR IN ABOUT THE 1-2K FT RANGE. MODEL
TIMING OF SHOWERS REMAINS CONSISTENT WITH ACTIVITY KICKING OFF BY
MID MORNING AND WRAPPING UP BY MID AFTERNOON. CIGS ARE EXPECTED TO
LIFT TO VFR THIS AFTERNOON AND EVENING...BUT LOOKS LIKE SOME
CLOUDINESS WILL LINGER INTO THE OVERNIGHT HOURS. SMR

&&

.MARINE...A FRONT WILL PASS EASTWARD ACROSS THE WATERS THIS EARLY
MORNING...ENHANCING ONSHORE FLOW INTO THIS EVENING. SMALL CRAFT
ADVISORIES REMAIN IN PLACE FOR CENTRAL AND EASTERN STRAIT AND HAVE
BEEN EXTENDED INTO LATE TONIGHT. WHILE THERE MAY BE A BRIEF PERIOD
WHERE WINDS WILL FALL BELOW ADVISORY CRITERIA...DID NOT WANT TO
SPLIT HAIRS AS WINDS WILL PICK UP AGAIN AS FRONT MOVES THROUGH. WITH
THAT INCREASE IN WINDS...WATERS IMPACTED BY SMALL CRAFT ADVISORY
WIND SPEEDS WILL INCLUDED COASTAL WATERS...NORTHERN INLAND
WATERS...AND THE WEST ENTRANCE. THUS ALL HAVE THEIR OWN ADVISORIES
IN PLACE WITH START AND END TIMES STAGGERED ACCORDINGLY. ADVISORIES
FOR COASTAL WATERS MAY NEED TO BE EXTENDED INTO SUNDAY...BUT THAT IS
BEST LEFT TO FUTURE FORECASTS.

A TURN TO NORTHERLY ONSHORE FLOW IS EXPECTED ON SATURDAY.
NORTHERLY OFFSHORE FLOW IS EXPECTED ON SUNDAY. NORTHERLIES COULD
REACH SMALL CRAFT STRENGTH IN PUGET SOUND ON SUNDAY PM. HANER/SMR

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 5 PM PDT
     SATURDAY FOR COASTAL WATERS FROM CAPE FLATTERY TO JAMES
     ISLAND 10 TO 60 NM-COASTAL WATERS FROM JAMES ISLAND TO
     POINT GRENVILLE 10 TO 60 NM-COASTAL WATERS FROM POINT
     GRENVILLE TO CAPE SHOALWATER 10 TO 60 NM.

     SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 5 AM PDT
     SATURDAY FOR COASTAL WATERS FROM CAPE FLATTERY TO JAMES
     ISLAND OUT 10 NM-COASTAL WATERS FROM JAMES ISLAND TO POINT
     GRENVILLE OUT 10 NM-COASTAL WATERS FROM POINT GRENVILLE TO
     CAPE SHOALWATER OUT 10 NM-WEST ENTRANCE U.S. WATERS STRAIT
     OF JUAN DE FUCA.

     SMALL CRAFT ADVISORY UNTIL 5 AM PDT SATURDAY FOR CENTRAL U.S.
     WATERS STRAIT OF JUAN DE FUCA-EAST ENTRANCE U.S. WATERS
     STRAIT OF JUAN DE FUCA.

     SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO NOON PDT SATURDAY
     FOR NORTHERN INLAND WATERS INCLUDING THE SAN JUAN ISLANDS.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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





000
FXUS66 KSEW 290354
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PDT THU APR 28 2016

.SYNOPSIS...WEAK UPPER LEVEL RIDGE MOVING EAST OF THE AREA THIS
EVENING. A FRONT AND ITS UPPER TROUGH WILL BRING SHOWERS LATE
TONIGHT AND FRIDAY. A STRONG UPPER RIDGE WILL BRING DRY WARMER
WEATHER SATURDAY THROUGH MONDAY. A CHANCE OF PRECIPITATION WILL
RETURN TUESDAY THROUGH THURSDAY OF NEXT WEEK.

&&

.SHORT TERM...ONSHORE FLOW AND AN APPROACHING FRONTAL SYSTEM WILL
KEEP SKIES CLOUDY TONIGHT. A FEW SHOWERS ARE STARTING TO DEVELOP IN
SNOHOMISH COUNTY WHERE THERE IS LOW LEVEL CONVERGENCE. SHOWERS WILL
INCREASE IN COVERAGE FRIDAY MORNING AS THE COLD FRONT MOVES
INLAND...BUT OVERALL THIS SYSTEM DOES NOT LOOK TOO IMPRESSIVE. THE
INFRARED SATELLITE SHOWS SOME SIGNS OF SPLITTING AS THIS FRONT
APPROACHES. SHOWERS WILL TAPER OFF FRIDAY EVENING AS THE TRAILING
UPPER LEVEL TROUGH EXITS. IT WILL BE ANOTHER COOL DAY WITH
TEMPERATURES MAINLY IN THE MID TO UPPER 50S.

SATURDAY IS STILL LOOKING DRY AND MILD AS AN UPPER LEVEL RIDGE
PUSHES INLAND. NORTHERLY FLOW SHOULD HELP SCOUR OUT THE MORNING LOW
CLOUDS. FORECAST MAX TEMPS ARE BACK IN THE 60S...A FEW DEGREES ABOVE
NORMAL.

THE UPPER LEVEL RIDGE WILL REMAIN OVER THE REGION ON SUNDAY FOR
ANOTHER DRY DAY. LOW LEVEL OFFSHORE FLOW WILL INCREASE AS A THERMAL
TROUGH FORMS ALONG THE COAST. THE DRY OFFSHORE FLOW WILL HELP BOOST
TEMPS INTO THE 70S TO LOWER 80S...ESPECIALLY ACROSS THE INTERIOR AND
COAST. THE COOL SPOTS WILL BE THE STRAIT AND SAN JUANS WITH HIGHS IN
THE MID 60S TO LOWER 70S. 33

.LONG TERM...PREVIOUS DISCUSSION...EXTENDED MODELS IN GOOD AGREEMENT
WITH THE LOW LEVEL OFFSHORE FLOW WEAKENING ON MONDAY WITH THE
GRADIENTS TURNING WEAKLY ONSHORE ALONG THE COAST IN THE AFTERNOON.
THIS WILL COOL THE HIGH TEMPERATURES DOWN ALONG THE COAST WHILE OVER
THE INTERIOR MONDAY LOOKS TO BE THE WARMEST DAY IN THIS MINI HEAT
WAVE WITH HIGHS IN THE 70S AND LOWER 80S. SPLITTING FRONT
APPROACHING THE COAST ON TUESDAY WITH A SMALL CHANCE OF SHOWERS OVER
THE AREA. LOW LEVEL FLOW TURNS ONSHORE FOR THE ENTIRE AREA ON
TUESDAY. THIS CHANCE IN THE LOW LEVEL FLOW WILL LOWER HIGH
TEMPERATURES AROUND 10 DEGREES. WHAT IS LEFT OF THE FRONT MOVING
THROUGH THE AREA TUESDAY NIGHT. UPPER LEVEL TROUGH WILL REMAIN OFF
THE COAST TUESDAY NIGHT THROUGH THURSDAY KEEPING A CHANCE OF SHOWERS
IN THE FORECAST. WITH THE LOW LEVEL ONSHORE FLOW TEMPERATURES WILL
CONTINUE TO COOL DOWN WITH 60S EXPECTED WEDNESDAY AND THURSDAY.
FELTON

&&

.AVIATION...AN UPPER TROUGH AXIS WILL PASS WRN WA ON FRIDAY MORNING.
AIR MASS SOMEWHAT MOIST AND STABLE TODAY...WITH MOISTURE AND
INSTABILITY INCREASING AS TROUGH AXIS PASSES THROUGH FRIDAY. SHOWERS
AND FAIRLY WIDESPREAD IFR CIGS EXPECTED FRIDAY MORNING. SHOWERS
ENDING AND GRADUAL CLEARING FRI AFTN AND EVNG FROM WEST TO EAST.
LIGHT AND VARIABLE FLOW ALOFT TODAY...BECOMING LIGHT NW ON FRI.

KSEA...NOT SEEING PSCZ DEVELOP AS PREVIOUS SHIFT THOUGHT...SO
GENERALLY EXPECTING SOUTHWEST WINDS THIS EVENING SHIFTING TO THE
SOUTHEAST TONIGHT WITH CIGS REMAINING VFR THROUGH TONIGHT. THE
PASSAGE OF A FRONT FRI MORNING WILL ENHANCE MOIST LOW-LEVEL ONSHORE
FLOW...BRINGING IFR CIGS EARLY FRI MORNING IN THE 1000-2000 FOOT
RANGE...ALONG WITH A FEW HOURS OF RAIN. CIGS LIFTING ON FRI AFTN TO
NEAR 030-040...THEN SCATTERING OUT ON FRI EVNG.  HANER/SMR

&&

.MARINE...A FRONT WILL PASS EASTWARD ACROSS THE WATERS FRIDAY
MORNING...ENHANCING ONSHORE FLOW THIS EVENING AND AGAIN FRIDAY
EVENING. SMALL CRAFT ADVISORIES REMAIN IN PLACE FOR CENTRAL AND
EASTERN STRAIT...AND CURRENT OBS LOOK LIKE THE ADVISORY LOOKS GOOD
FOR CENTRAL STRAIT. EASTERN STRAIT LOOKS TO HAVE FALLEN BELOW
CRITERIA...BUT WILL KEEP ADVISORY UP FOR EVENING FORECAST. WILL
LIKELY NEED ANOTHER ROUND OF ADVISORIES FOR MOST WATERS FOR
FRIDAY...BUT WILL WAIT AND ISSUE WITH EARLY MORNING FORECAST
PACKAGE. A TURN TO NORTHERLY ONSHORE FLOW IS EXPECTED ON SATURDAY.
NORTHERLY OFFSHORE FLOW IS EXPECTED ON SUNDAY. NORTHERLIES COULD
REACH SMALL CRAFT STRENGTH IN PUGET SOUND ON SUNDAY PM.   HANER/SMR

&&

.SEW WATCHES/WARNINGS/ADVISORIES...

WA...NONE.
PZ...SMALL CRAFT ADVISORY CENTRAL AND EASTERN STRAIT.

&&

$$

WWW.WEATHER.GOV/SEATTLE

ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION CAN BE SEEN AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML





000
FXUS66 KSEW 282230
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
330 PM PDT THU APR 28 2016

.SYNOPSIS...WEAK UPPER LEVEL RIDGE MOVING EAST OF THE AREA THIS
EVENING. A FRONT AND ITS UPPER TROUGH WILL BRING SHOWERS LATE
TONIGHT AND FRIDAY. A STRONG UPPER RIDGE WILL BRING DRY WARMER
WEATHER SATURDAY THROUGH MONDAY. A CHANCE OF PRECIPITATION WILL
RETURN TUESDAY THROUGH THURSDAY OF NEXT WEEK.

&&

.SHORT TERM...SATELLITE IMAGERY SHOWS A LOT OF SC OVER WESTERN
WASHINGTON THIS AFTERNOON WITH A WEAK FRONT WELL OFFSHORE. RADAR
NOT PICKING UP ANY SHOWER ACTIVITY AS OF 22Z/3PM. TEMPERATURES AT
3 PM WERE IN THE MID 50S TO MID 60S.

FRONT OFFSHORE WILL CONTINUE TO APPROACH TONIGHT WITH THE UPPER
LEVEL RIDGE CONTINUING TO MOVE EAST. AIR MASS SLIGHTLY UNSTABLE
LATE THIS AFTERNOON INTO THIS EVENING SO A LIGHT SHOWER OVER THE
HIGHER TERRAIN CAN NOT BE RULED OUT. ONSHORE FLOW AT THE LOWER
LEVELS TONIGHT WITH A SURFACE RIDGE OUT AHEAD OF THE FRONT. BEST
CHANCES FOR SHOWERS AFTER MIDNIGHT ALONG THE COAST AND IN A WEAK
CONVERGENCE ZONE OVER NORTHERN SNOHOMISH AND SOUTHERN SKAGIT
COUNTY. LOWS TONIGHT WILL BE IN THE 40S TO NEAR 50.

FRONT MOVING THROUGH WESTERN WASHINGTON FRIDAY MORNING INTO THE
EARLY AFTERNOON HOURS. POSSIBLE CONVERGENCE CONTINUING NEAR THE
EAST ENTRANCE OF THE STRAIT OF JUAN DE FUCA. SHOWERS WILL DECREASE
IN THE AFTERNOON HOURS ESPECIALLY WEST OF PUGET SOUND. HIGHS ON
FRIDAY WILL BE COOL...MOSTLY IN THE 50S.

SHOWER CHANCES DECREASING QUICKLY FRIDAY NIGHT AS AN UPPER LEVEL
RIDGE BUILDS OFF THE COAST. LOW LEVEL ONSHORE FLOW STILL KEEPING
MOSTLY CLOUDY SKIES OVER MOST OF THE AREA. LOWS WILL BE MOSTLY IN
THE 40S.

UPPER LEVEL RIDGE BEGINNING TO NOSE IN OVER WESTERN WASHINGTON ON
SATURDAY WITH 500 MB HEIGHTS UP TO THE LOWER TO MID 570 DECAMETERS
BY 00Z SUNDAY. SURFACE GRADIENTS REMAINING NORTHWESTERLY ALL DAY
SO EVEN THOUGH TEMPERATURES ALOFT WARM UP HIGHS ON SATURDAY WILL
ONLY MOSTLY BE IN THE 60S WITH THE WARMER LOCATIONS IN THE LOWER
70S.

SURFACE GRADIENTS TURN OFFSHORE OVERNIGHT SATURDAY NIGHT INTO
SUNDAY MORNING WITH A THERMALLY INDUCED TROUGH DEVELOPING ALONG
THE COAST. WINDS FROM 850 MB TO THE SURFACE ALSO TURNING EASTERLY.
TEMPERATURES ALOFT WARMING WITH THE MODEL 850 MB TEMPERATURES
PLUS 10 TO PLUS 13C AT 00Z MONDAY. HIGHS WILL WARM ON SUNDAY INTO
THE 70S AND LOWER 80S.

.LONG TERM...EXTENDED MODELS IN GOOD AGREEMENT WITH THE LOW LEVEL
OFFSHORE FLOW WEAKENING ON MONDAY WITH THE GRADIENTS TURNING
WEAKLY ONSHORE ALONG THE COAST IN THE AFTERNOON. THIS WILL COOL
THE HIGH TEMPERATURES DOWN ALONG THE COAST WHILE OVER THE INTERIOR
MONDAY LOOKS TO BE THE WARMEST DAY IN THIS MINI HEAT WAVE WITH
HIGHS IN THE 70S AND LOWER 80S. SPLITTING FRONT APPROACHING THE
COAST ON TUESDAY WITH A SMALL CHANCE OF SHOWERS OVER THE AREA. LOW
LEVEL FLOW TURNS ONSHORE FOR THE ENTIRE AREA ON TUESDAY. THIS
CHANCE IN THE LOW LEVEL FLOW WILL LOWER HIGH TEMPERATURES AROUND
10 DEGREES. WHAT IS LEFT OF THE FRONT MOVING THROUGH THE AREA
TUESDAY NIGHT. UPPER LEVEL TROUGH WILL REMAIN OFF THE COAST
TUESDAY NIGHT THROUGH THURSDAY KEEPING A CHANCE OF SHOWERS IN THE
FORECAST. WITH THE LOW LEVEL ONSHORE FLOW TEMPERATURES WILL
CONTINUE TO COOL DOWN WITH 60S EXPECTED WEDNESDAY AND THURSDAY.
FELTON

&&

.AVIATION...AN UPPER TROUGH AXIS WILL PASS WRN WA ON FRI
MORNING. AIR MASS SOMEWHAT MOIST AND STABLE TODAY...BECOMING MORE
MOIST AND MORE UNSTABLE ON FRI. SHOWERS AND FAIRLY WIDESPREAD IFR
CONDS EXPECTED FRI MORNING. SHOWERS ENDING AND GRADUAL CLEARING FRI
AFTN AND EVNG...FIRST NEAR THE WATERS. LIGHT AND VARIABLE FLOW ALOFT
TODAY...BECOMING LIGHT NW ON FRI.

KSEA...PUGET SOUND CONVERGENCE ZONE MAY SLIP JUST SOUTH OF THE
TERMINAL THIS EVNG...BRINGING A SHIFT TO NORTHERLY WINDS ARND
02Z. NLY WINDS WOULD LAST FOR 2-4 HOURS. THE PASSAGE OF A FRONT ON
FRI MORNING WILL ENHANCE MOIST LOW-LEVEL ONSHORE FLOW...BRINGING IFR
CIGS ON FRI MORNING IN THE 1000-2000 FOOT RANGE...ALONG WITH A FEW
HOURS OF RAIN. CIGS LIFTING ON FRI AFTN TO NEAR 030-040...THEN
SCATTERING OUT ON FRI EVNG.     HANER

&&

.MARINE...A FRONT WILL PASS EASTWARD ACROSS THE WATERS ON FRI
MORNING...ENHANCING ONSHORE FLOW THIS EVENING AND AGAIN ON FRI EVNG.
A TURN TO NORTHERLY ONSHORE FLOW IS EXPECTED ON SATURDAY. NORTHERLY
OFFSHORE FLOW IS EXPECTED ON SUNDAY. NORTHERLIES COULD REACH SMALL
CRAFT STRENGTH IN PUGET SOUND ON SUNDAY PM.     HANER

&&

.SEW WATCHES/WARNINGS/ADVISORIES...

WA...NONE.

PZ...SMALL CRAFT ADVISORY UNTIL 8 AM PDT FRIDAY FOR EAST ENTRANCE
     U.S. WATERS STRAIT OF JUAN DE FUCA.

     SMALL CRAFT ADVISORY UNTIL 10 PM PDT THIS EVENING FOR WEST
     ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.

     SMALL CRAFT ADVISORY UNTIL 8 AM PDT FRIDAY FOR CENTRAL 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





000
FXUS66 KSEW 282230
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
330 PM PDT THU APR 28 2016

.SYNOPSIS...WEAK UPPER LEVEL RIDGE MOVING EAST OF THE AREA THIS
EVENING. A FRONT AND ITS UPPER TROUGH WILL BRING SHOWERS LATE
TONIGHT AND FRIDAY. A STRONG UPPER RIDGE WILL BRING DRY WARMER
WEATHER SATURDAY THROUGH MONDAY. A CHANCE OF PRECIPITATION WILL
RETURN TUESDAY THROUGH THURSDAY OF NEXT WEEK.

&&

.SHORT TERM...SATELLITE IMAGERY SHOWS A LOT OF SC OVER WESTERN
WASHINGTON THIS AFTERNOON WITH A WEAK FRONT WELL OFFSHORE. RADAR
NOT PICKING UP ANY SHOWER ACTIVITY AS OF 22Z/3PM. TEMPERATURES AT
3 PM WERE IN THE MID 50S TO MID 60S.

FRONT OFFSHORE WILL CONTINUE TO APPROACH TONIGHT WITH THE UPPER
LEVEL RIDGE CONTINUING TO MOVE EAST. AIR MASS SLIGHTLY UNSTABLE
LATE THIS AFTERNOON INTO THIS EVENING SO A LIGHT SHOWER OVER THE
HIGHER TERRAIN CAN NOT BE RULED OUT. ONSHORE FLOW AT THE LOWER
LEVELS TONIGHT WITH A SURFACE RIDGE OUT AHEAD OF THE FRONT. BEST
CHANCES FOR SHOWERS AFTER MIDNIGHT ALONG THE COAST AND IN A WEAK
CONVERGENCE ZONE OVER NORTHERN SNOHOMISH AND SOUTHERN SKAGIT
COUNTY. LOWS TONIGHT WILL BE IN THE 40S TO NEAR 50.

FRONT MOVING THROUGH WESTERN WASHINGTON FRIDAY MORNING INTO THE
EARLY AFTERNOON HOURS. POSSIBLE CONVERGENCE CONTINUING NEAR THE
EAST ENTRANCE OF THE STRAIT OF JUAN DE FUCA. SHOWERS WILL DECREASE
IN THE AFTERNOON HOURS ESPECIALLY WEST OF PUGET SOUND. HIGHS ON
FRIDAY WILL BE COOL...MOSTLY IN THE 50S.

SHOWER CHANCES DECREASING QUICKLY FRIDAY NIGHT AS AN UPPER LEVEL
RIDGE BUILDS OFF THE COAST. LOW LEVEL ONSHORE FLOW STILL KEEPING
MOSTLY CLOUDY SKIES OVER MOST OF THE AREA. LOWS WILL BE MOSTLY IN
THE 40S.

UPPER LEVEL RIDGE BEGINNING TO NOSE IN OVER WESTERN WASHINGTON ON
SATURDAY WITH 500 MB HEIGHTS UP TO THE LOWER TO MID 570 DECAMETERS
BY 00Z SUNDAY. SURFACE GRADIENTS REMAINING NORTHWESTERLY ALL DAY
SO EVEN THOUGH TEMPERATURES ALOFT WARM UP HIGHS ON SATURDAY WILL
ONLY MOSTLY BE IN THE 60S WITH THE WARMER LOCATIONS IN THE LOWER
70S.

SURFACE GRADIENTS TURN OFFSHORE OVERNIGHT SATURDAY NIGHT INTO
SUNDAY MORNING WITH A THERMALLY INDUCED TROUGH DEVELOPING ALONG
THE COAST. WINDS FROM 850 MB TO THE SURFACE ALSO TURNING EASTERLY.
TEMPERATURES ALOFT WARMING WITH THE MODEL 850 MB TEMPERATURES
PLUS 10 TO PLUS 13C AT 00Z MONDAY. HIGHS WILL WARM ON SUNDAY INTO
THE 70S AND LOWER 80S.

.LONG TERM...EXTENDED MODELS IN GOOD AGREEMENT WITH THE LOW LEVEL
OFFSHORE FLOW WEAKENING ON MONDAY WITH THE GRADIENTS TURNING
WEAKLY ONSHORE ALONG THE COAST IN THE AFTERNOON. THIS WILL COOL
THE HIGH TEMPERATURES DOWN ALONG THE COAST WHILE OVER THE INTERIOR
MONDAY LOOKS TO BE THE WARMEST DAY IN THIS MINI HEAT WAVE WITH
HIGHS IN THE 70S AND LOWER 80S. SPLITTING FRONT APPROACHING THE
COAST ON TUESDAY WITH A SMALL CHANCE OF SHOWERS OVER THE AREA. LOW
LEVEL FLOW TURNS ONSHORE FOR THE ENTIRE AREA ON TUESDAY. THIS
CHANCE IN THE LOW LEVEL FLOW WILL LOWER HIGH TEMPERATURES AROUND
10 DEGREES. WHAT IS LEFT OF THE FRONT MOVING THROUGH THE AREA
TUESDAY NIGHT. UPPER LEVEL TROUGH WILL REMAIN OFF THE COAST
TUESDAY NIGHT THROUGH THURSDAY KEEPING A CHANCE OF SHOWERS IN THE
FORECAST. WITH THE LOW LEVEL ONSHORE FLOW TEMPERATURES WILL
CONTINUE TO COOL DOWN WITH 60S EXPECTED WEDNESDAY AND THURSDAY.
FELTON

&&

.AVIATION...AN UPPER TROUGH AXIS WILL PASS WRN WA ON FRI
MORNING. AIR MASS SOMEWHAT MOIST AND STABLE TODAY...BECOMING MORE
MOIST AND MORE UNSTABLE ON FRI. SHOWERS AND FAIRLY WIDESPREAD IFR
CONDS EXPECTED FRI MORNING. SHOWERS ENDING AND GRADUAL CLEARING FRI
AFTN AND EVNG...FIRST NEAR THE WATERS. LIGHT AND VARIABLE FLOW ALOFT
TODAY...BECOMING LIGHT NW ON FRI.

KSEA...PUGET SOUND CONVERGENCE ZONE MAY SLIP JUST SOUTH OF THE
TERMINAL THIS EVNG...BRINGING A SHIFT TO NORTHERLY WINDS ARND
02Z. NLY WINDS WOULD LAST FOR 2-4 HOURS. THE PASSAGE OF A FRONT ON
FRI MORNING WILL ENHANCE MOIST LOW-LEVEL ONSHORE FLOW...BRINGING IFR
CIGS ON FRI MORNING IN THE 1000-2000 FOOT RANGE...ALONG WITH A FEW
HOURS OF RAIN. CIGS LIFTING ON FRI AFTN TO NEAR 030-040...THEN
SCATTERING OUT ON FRI EVNG.     HANER

&&

.MARINE...A FRONT WILL PASS EASTWARD ACROSS THE WATERS ON FRI
MORNING...ENHANCING ONSHORE FLOW THIS EVENING AND AGAIN ON FRI EVNG.
A TURN TO NORTHERLY ONSHORE FLOW IS EXPECTED ON SATURDAY. NORTHERLY
OFFSHORE FLOW IS EXPECTED ON SUNDAY. NORTHERLIES COULD REACH SMALL
CRAFT STRENGTH IN PUGET SOUND ON SUNDAY PM.     HANER

&&

.SEW WATCHES/WARNINGS/ADVISORIES...

WA...NONE.

PZ...SMALL CRAFT ADVISORY UNTIL 8 AM PDT FRIDAY FOR EAST ENTRANCE
     U.S. WATERS STRAIT OF JUAN DE FUCA.

     SMALL CRAFT ADVISORY UNTIL 10 PM PDT THIS EVENING FOR WEST
     ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.

     SMALL CRAFT ADVISORY UNTIL 8 AM PDT FRIDAY FOR CENTRAL 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





000
FXUS66 KSEW 281648
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
948 AM PDT THU APR 28 2016

.SYNOPSIS...WEAK UPPER LEVEL RIDGE MOVING ACROSS WESTERN
WASHINGTON TODAY. SPOTTY LIGHT SHOWERS COULD DEVELOP OVER THE
MOUNTAINS LATE. A FRONT AND ITS UPPER TROUGH WILL BRING SHOWERS LATE
TONIGHT AND FRIDAY. A STRONG UPPER RIDGE WILL BRING DRY WARMER
WEATHER SATURDAY THROUGH MONDAY. A CHANCE OF PRECIPITATION WILL
RETURN TUESDAY THROUGH WEDNESDAY.

&&

.SHORT TERM...SATELLITE IMAGERY SHOWS SC DECK OVER WESTERN
WASHINGTON BETWEEN THE PUGET SOUND AND THE CASCADES. SOME SC ALSO
ALONG THE NORTH COAST WITH A BIG CLEAR AREA FROM THE CENTRAL STRAIT
OF JUAN DE FUCA THROUGH THE OLYMPICS DOWN TO THE LOWER CHEHALIS
VALLEY. TEMPERATURES AT 9 AM WERE IN THE MID 40S TO MID 50S.

WEAK UPPER LEVEL RIDGE MOVING THROUGH THE AREA TODAY. SC DECK
OVER THE INTERIOR IS FAIRLY THIN WITH THE BASES IN THE 6000-7000
FOOT RANGE AND THE TOPS WELL BELOW 10,000 FEET ON THE CAMP MUIR
WEBCAM. THE COMBINATION OF LARGE BREAKS IN THE CLOUD COVER
ALREADY...UPPER LEVEL RIDGE MOVING THROUGH AND THE CLOUD DECK
BEING PRETTY THIN WILL STAY WITH THE PARTLY SUNNY WORDING FOR THE
INTERIOR ZONES TODAY FROM THE PUGET SOUND EASTWARD. WILL DO A
QUICK UPDATE TO DECREASE THE CLOUD COVER FOR THE ZONES WEST OF
THE SOUND. EVEN WITH THE REDUCED CLOUD COVER TEMPERATURES ALOFT
ARE NOT VERY WARM...MODEL 850 MB TEMPS PLUS 2 TO PLUS 4C...SO WILL
STAY WITH THE FORECAST HIGH TEMPERATURE RANGE OF UPPER 50S TO MID
60S.

UPPER LEVEL RIDGE EAST OF THE AREA TONIGHT WITH A WEAK UPPER LEVEL
TROUGH APPROACHING THE COAST. THE TROUGH WILL BE CLOSE ENOUGH TO
THE COAST BY EARLY FRIDAY MORNING TO PUT A CHANCE OF SHOWERS IN
THE FORECAST AFTER MIDNIGHT TONIGHT. TROUGH MOVING THROUGH WESTERN
WASHINGTON ON FRIDAY FOR WIDESPREAD SHOWER ACTIVITY. RAINFALL
AMOUNTS WILL NOT BE MUCH...A TENTH OR SO OVER THE INTERIOR AND
SLIGHTLY MORE OVER THE MOUNTAINS. HIGHS WILL BE A FEW DEGREES
COOLER THAN TODAY ON FRIDAY WITH MID AND UPPER 50S COMMON.

SHOWER ACTIVITY DRYING UP QUICKLY FRIDAY EVENING AS AN UPPER LEVEL
RIDGE BUILDS OFFSHORE. RIDGE CONTINUING TO BUILD ON SATURDAY WITH
TEMPERATURES ALOFT WARMING. MODEL 850 MB TEMPERATURES IN THE PLUS
5 TO 8C RANGE BY 00Z SUNDAY. SURFACE GRADIENTS REMAINING
NORTHWESTERLY SO AFTERNOON SEABREEZES WILL CAP THE HIGHS ON
SATURDAY IN THE 60S FOR THE MOST PART WITH LOCATIONS NEAR THE
WATER IN THE UPPER 50S. NO CHANGES TO THE FORECAST THIS MORNING
OTHER THAN THE CLOUD COVER FOR TODAY. FELTON

.LONG TERM...PREVIOUS DISCUSSION FOLLOWS. THE UPPER RIDGE WILL MOVE
TO AROUND THE COAST SUNDAY AND THEN INLAND MONDAY. THERE WILL BE
SUNSHINE BOTH DAYS. HIGHS SHOULD BE IN THE MID TO UPPER 70S OVER
MUCH OF THE AREA ON SUNDAY AND INTO THE LOWER 80S ON MONDAY. IT
LOOKS LIKE THE RIDGE WILL MOVE EAST AND BREAK DOWN AFTER
THAT...BUT MODELS DIFFER ON HOW THAT WILL HAPPEN. MOIST SOUTHERLY
FLOW ALOFT WEST OF THE RIDGE COULD BRING SOME SHOWERS AND
CONVECTION INTO THE AREA MONDAY NIGHT OR TUESDAY...OR POSSIBLY A
MORE ORGANIZED SYSTEM WILL ARRIVE FROM THE WEST. AT ANY
RATE...THERE IS A CHANCE OF PRECIPITATION AGAIN MONDAY NIGHT
THROUGH WEDNESDAY. MCDONNAL

&&

.AVIATION...UPPER LEVEL RIDGE AXIS PASSING WRN WA THIS
AFTN...FOLLOWED BY THE PASSAGE OF AN UPPER TROUGH AXIS ON FRI
MORNING. AIR MASS SOMEWHAT MOIST AND STABLE TODAY...BECOMING MORE
MOIST AND MORE UNSTABLE ON FRI. SHOWERS AND FAIRLY WIDESPREAD IFR
CONDS EXPECTED FRI MORNING. LIGHT AND VARIABLE FLOW ALOFT
TODAY...BECOMING LIGHT NW ON FRI.

KSEA...CIGS RISING THIS AFTN WITH DAYTIME HEATING...GENERALLY
REMAINING AT OR ABOVE 5000 FEET THROUGH THIS EVNG. PUGET SOUND
CONVERGENCE ZONE MAY SLIP JUST SOUTH OF THE TERMINAL THIS
EVNG...BRINGING A SHIFT TO NORTHERLY WINDS ARND 02Z...THEN LASTING
FOR A FEW HOURS. THE PASSAGE OF A FRONT ON FRI MORNING WILL ENHANCE
MOIST LOW-LEVEL ONSHORE FLOW...BRINGING IFR CIGS ON FRI MORNING IN
THE 1000-2000 FOOT RANGE...ALONG WITH A FEW HOURS OF RAIN. CIGS
LIFTING ON FRI AFTN TO NEAR 030-040...BUT HAVING A HARD TIME
ACTUALLY SCATTERING OUT ON FRI AFTN.       HANER

&&

.MARINE...THE EASTWARD PASSAGE OF A FRONT WILL START ENHANCE ONSHORE
FLOW THIS AFTERNOON AND EVENING. THE FRONT WILL PASS ON FRIDAY
MORNING...FOLLOWED BY A RENEWED ROUND OF ONSHORE FLOW ON FRIDAY
AFTERNOON AND EVENING. A TURN TO NORTHERLY ONSHORE FLOW IS EXPECTED
ON SATURDAY. NORTHERLY OFFSHORE FLOW IS EXPECTED ON SUNDAY.   HANER

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 8 AM PDT FRIDAY
     FOR EAST ENTRANCE U.S. WATERS STRAIT OF JUAN DE FUCA.

     SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 11 PM PDT THIS
     EVENING FOR WEST ENTRANCE U.S. WATERS STRAIT OF JUAN DE
     FUCA.

     SMALL CRAFT ADVISORY FROM 2 PM THIS AFTERNOON TO 8 AM PDT FRIDAY
     FOR CENTRAL 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





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