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000
FXUS66 KSEW 182203
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
303 PM PDT SAT APR 18 2015

.SYNOPSIS...HIGH PRESSURE ALOFT WILL REMAIN OVER THE REGION
THROUGH MONDAY FOR CONTINUED WARM WEATHER. THE HIGH WILL MOVE
EAST ON TUESDAY...ALLOWING A LOW PRESSURE SYSTEM TO APPROACH. THE
MAIN IMPACTS WILL BE COOLER TEMPERATURES AND INCREASED CLOUD
COVER. UNSETTLED CONDITIONS WILL PREVAIL WEDNESDAY THROUGH THE END
OF THE UPCOMING WEEK.

&&

.SHORT TERM...
SMOKE FROM LARGE WILDFIRES IN SIBERIA AND THIN CIRRUS WERE
DRIFTING ACROSS THE CWA THIS AFTERNOON. THERE WAS ALSO A
STUBBORN AREA OF STRATUS LURKING JUST OFF THE COAST. TEMPS THIS
AFTERNOON WERE RUNNING ABOVE NORMAL ACROSS MUCH OF THE CWA.
HOWEVER...NORTHERLY SEA BREEZES WERE KEEPING A NUMBER OF LOCATIONS
IMMEDIATELY ADJACENT TO THE PUGET SOUND...NORTHERN INLAND WATERS...
AND STRAIT OF JUAN DE FUCA FROM REACHING THEIR TRUE POTENTIAL.

AN UPPER RIDGE WILL REMAIN OVER THE PACIFIC NORTHWEST THROUGH MON.
THE RIDGE AXIS WILL MOVE OVER THE INTERIOR WEST ON TUE...ALLOWING
AN UPPER TROF TO APPROACH THE COAST FROM THE WEST. THE MAIN
FORECAST PROBLEM DURING THIS PERIOD WILL BE THE ONSHORE PRESSURE
GRADIENT...IN PARTICULAR THE ONSET OF THE MARINE PUSH...WHICH WILL
HAVE AN IMPACT ON DAYTIME TEMPS.

IT LOOKS LIKE THE NORTHWEST TO SOUTHEAST PRESSURE GRADIENT WILL
REMAIN TIGHT ENOUGH THROUGH SUNDAY FOR A RISK OF LATE NIGHT AND
MORNING STRATUS AND/OR FOG ON THE COAST. ALSO...THIS WILL LIKELY
KEEP MAX TEMPS FROM REALIZING THEIR TRUE POTENTIAL ACROSS THOSE
AREAS IMMEDIATELY ADJACENT TO MAJOR WATER BODIES.

THE FORECAST FOR MON WAS A BIT TRICKY. THE UPPER RIDGE AXIS WILL
BE RIGHT OVER THE CWA IN THE AFTERNOON...WHICH SHOULD RESULT IN
WARMER TEMPS...ESPECIALLY OVER THE INTERIOR. THE QUESTION WAS HOW
MUCH. EARLIER MODEL SOLUTIONS HAD THE RIDGE AXIS TO OUR EAST MON
AFTERNOON. THERE IS A CHANCE THAT THEY WILL REVERT BACK TO THIS
SOLUTION...THUS DECIDED TO PLAY IT CONSERVATIVELY FOR NOW. TEMPS
ON THE COAST MON SHOULD BE SIMILAR TO SUNDAY OR PERHAPS A FEW
DEGREES COOLER.

FOR NOW...IT LOOKS LIKE THE MARINE PUSH WILL OCCUR MON NIGHT OR
DURING THE DAY TUE. IF IT OCCURS MON NIGHT...THE FORECAST TEMPS
FOR TUE WILL BE TOO WARM...ESPECIALLY FOR THE INTERIOR. IF IT
OCCURS DURING THE DAY TUE THAN THE FORECAST TEMPS MAY HOLD. AT ANY
RATE...ANTICIPATE INCREASED CLOUD COVER ON TUE. THERE WILL ALSO BE
A RISK OF TSTMS OVER THE CASCADES...MAINLY NEAR THE CREST...TUE
AFTERNOON.

.LONG TERM...
NO MAJOR CHANGES TO THE OVERALL SYNOPTIC SCALE PICTURE. IT STILL
APPEARED THAT THE PACIFIC NORTHWEST WILL ENTER A COOLER AND
UNSETTLED PATTERN DURING THIS PERIOD. HOWEVER...CONFIDENCE IN THE
DETAILS WERE LOW DUE TO LACK OF AGREEMENT AND CONSISTENCY IN THE
MEDIUM RANGE SOLUTIONS. THE MODELS WERE ALSO OUT OF PHASE AT
TIMES. FOR EXAMPLE...ON WED...THE ECMWF HAD A WEAK UPPER RIDGE
OVER THE AREA WHEREAS THE GFS HAD A RELATIVELY STRONG...COLD
UPPER LOW OVER THE CWA. DECIDED NOT TO MAKE SIGNIFICANT CHANGES TO
THE INHERITED FORECAST FOR THE AFOREMENTIONED REASONS.

&&

.AVIATION...AN UPPER LEVEL RIDGE OVER THE PAC NW WILL GIVE CLEAR
SKIES AND A DRY STABLE AIR MASS OVER WRN WA THIS WEEKEND. THE FLOW
ALOFT IS NORTHWEST. AT 2 PM THERE WAS A PATCH OF MARINE STRATUS
ALONG THE COAST.

KSEA...CLEAR SKIES WITH A NORTHERLY BREEZE.

&&

.MARINE...AT 2 PM THE WIND AT DESTRUCTION ISLAND WAS STILL LESS THAN
10 KTS SO I DROPPED THE SMALL CRAFT ADVISORY FOR THE COASTAL WATERS.
THE 2 PM SEA LEVEL PRESSURE ANALYSIS SHOWS NOT MUCH PRES GRADIENT
OVER THE COASTAL WATERS. THE WIND SHOULD STILL INCREASE INTO THE
LATE AFTERNOON AND EVENING WITH A 10-20KT FORECAST FOR MOST AREAS.
THERE IS HIGH PRESSURE JUST OFFSHORE THAT EXTENDS THROUGH QUEEN
CHARLOTTE SOUND AND INTO B.C. WITH THERMALLY LOW PRESSURE CENTERED
OVER CALIF. A COLD FRONT WILL ARRIVE TUESDAY.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY IN EFFECT TIL 11 PM TONIGHT FOR THE
     COASTAL WATERS.

     SMALL CRAFT ADVISORY FOR ROUGH BAR IN EFFECT TIL 9 PM
     TONIGHT FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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





000
FXUS66 KSEW 182203
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
303 PM PDT SAT APR 18 2015

.SYNOPSIS...HIGH PRESSURE ALOFT WILL REMAIN OVER THE REGION
THROUGH MONDAY FOR CONTINUED WARM WEATHER. THE HIGH WILL MOVE
EAST ON TUESDAY...ALLOWING A LOW PRESSURE SYSTEM TO APPROACH. THE
MAIN IMPACTS WILL BE COOLER TEMPERATURES AND INCREASED CLOUD
COVER. UNSETTLED CONDITIONS WILL PREVAIL WEDNESDAY THROUGH THE END
OF THE UPCOMING WEEK.

&&

.SHORT TERM...
SMOKE FROM LARGE WILDFIRES IN SIBERIA AND THIN CIRRUS WERE
DRIFTING ACROSS THE CWA THIS AFTERNOON. THERE WAS ALSO A
STUBBORN AREA OF STRATUS LURKING JUST OFF THE COAST. TEMPS THIS
AFTERNOON WERE RUNNING ABOVE NORMAL ACROSS MUCH OF THE CWA.
HOWEVER...NORTHERLY SEA BREEZES WERE KEEPING A NUMBER OF LOCATIONS
IMMEDIATELY ADJACENT TO THE PUGET SOUND...NORTHERN INLAND WATERS...
AND STRAIT OF JUAN DE FUCA FROM REACHING THEIR TRUE POTENTIAL.

AN UPPER RIDGE WILL REMAIN OVER THE PACIFIC NORTHWEST THROUGH MON.
THE RIDGE AXIS WILL MOVE OVER THE INTERIOR WEST ON TUE...ALLOWING
AN UPPER TROF TO APPROACH THE COAST FROM THE WEST. THE MAIN
FORECAST PROBLEM DURING THIS PERIOD WILL BE THE ONSHORE PRESSURE
GRADIENT...IN PARTICULAR THE ONSET OF THE MARINE PUSH...WHICH WILL
HAVE AN IMPACT ON DAYTIME TEMPS.

IT LOOKS LIKE THE NORTHWEST TO SOUTHEAST PRESSURE GRADIENT WILL
REMAIN TIGHT ENOUGH THROUGH SUNDAY FOR A RISK OF LATE NIGHT AND
MORNING STRATUS AND/OR FOG ON THE COAST. ALSO...THIS WILL LIKELY
KEEP MAX TEMPS FROM REALIZING THEIR TRUE POTENTIAL ACROSS THOSE
AREAS IMMEDIATELY ADJACENT TO MAJOR WATER BODIES.

THE FORECAST FOR MON WAS A BIT TRICKY. THE UPPER RIDGE AXIS WILL
BE RIGHT OVER THE CWA IN THE AFTERNOON...WHICH SHOULD RESULT IN
WARMER TEMPS...ESPECIALLY OVER THE INTERIOR. THE QUESTION WAS HOW
MUCH. EARLIER MODEL SOLUTIONS HAD THE RIDGE AXIS TO OUR EAST MON
AFTERNOON. THERE IS A CHANCE THAT THEY WILL REVERT BACK TO THIS
SOLUTION...THUS DECIDED TO PLAY IT CONSERVATIVELY FOR NOW. TEMPS
ON THE COAST MON SHOULD BE SIMILAR TO SUNDAY OR PERHAPS A FEW
DEGREES COOLER.

FOR NOW...IT LOOKS LIKE THE MARINE PUSH WILL OCCUR MON NIGHT OR
DURING THE DAY TUE. IF IT OCCURS MON NIGHT...THE FORECAST TEMPS
FOR TUE WILL BE TOO WARM...ESPECIALLY FOR THE INTERIOR. IF IT
OCCURS DURING THE DAY TUE THAN THE FORECAST TEMPS MAY HOLD. AT ANY
RATE...ANTICIPATE INCREASED CLOUD COVER ON TUE. THERE WILL ALSO BE
A RISK OF TSTMS OVER THE CASCADES...MAINLY NEAR THE CREST...TUE
AFTERNOON.

.LONG TERM...
NO MAJOR CHANGES TO THE OVERALL SYNOPTIC SCALE PICTURE. IT STILL
APPEARED THAT THE PACIFIC NORTHWEST WILL ENTER A COOLER AND
UNSETTLED PATTERN DURING THIS PERIOD. HOWEVER...CONFIDENCE IN THE
DETAILS WERE LOW DUE TO LACK OF AGREEMENT AND CONSISTENCY IN THE
MEDIUM RANGE SOLUTIONS. THE MODELS WERE ALSO OUT OF PHASE AT
TIMES. FOR EXAMPLE...ON WED...THE ECMWF HAD A WEAK UPPER RIDGE
OVER THE AREA WHEREAS THE GFS HAD A RELATIVELY STRONG...COLD
UPPER LOW OVER THE CWA. DECIDED NOT TO MAKE SIGNIFICANT CHANGES TO
THE INHERITED FORECAST FOR THE AFOREMENTIONED REASONS.

&&

.AVIATION...AN UPPER LEVEL RIDGE OVER THE PAC NW WILL GIVE CLEAR
SKIES AND A DRY STABLE AIR MASS OVER WRN WA THIS WEEKEND. THE FLOW
ALOFT IS NORTHWEST. AT 2 PM THERE WAS A PATCH OF MARINE STRATUS
ALONG THE COAST.

KSEA...CLEAR SKIES WITH A NORTHERLY BREEZE.

&&

.MARINE...AT 2 PM THE WIND AT DESTRUCTION ISLAND WAS STILL LESS THAN
10 KTS SO I DROPPED THE SMALL CRAFT ADVISORY FOR THE COASTAL WATERS.
THE 2 PM SEA LEVEL PRESSURE ANALYSIS SHOWS NOT MUCH PRES GRADIENT
OVER THE COASTAL WATERS. THE WIND SHOULD STILL INCREASE INTO THE
LATE AFTERNOON AND EVENING WITH A 10-20KT FORECAST FOR MOST AREAS.
THERE IS HIGH PRESSURE JUST OFFSHORE THAT EXTENDS THROUGH QUEEN
CHARLOTTE SOUND AND INTO B.C. WITH THERMALLY LOW PRESSURE CENTERED
OVER CALIF. A COLD FRONT WILL ARRIVE TUESDAY.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY IN EFFECT TIL 11 PM TONIGHT FOR THE
     COASTAL WATERS.

     SMALL CRAFT ADVISORY FOR ROUGH BAR IN EFFECT TIL 9 PM
     TONIGHT FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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






000
FXUS66 KSEW 181612
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
912 AM PDT SAT APR 18 2015

.SYNOPSIS...HIGH PRESSURE ALOFT WILL PREVAIL OVER THE REGION
THROUGH MONDAY FOR DRY WEATHER WITH ABOVE NORMAL TEMPERATURES.
UNSETTLED AND COOLER CONDITIONS ARE ANTICIPATED TUESDAY THROUGH
THE END OF NEXT WEEK.

&&

.SHORT TERM...
SKIES WERE MOSTLY SUNNY OVER THE CWA THIS MORNING. THERE WAS
PATCHY FOG IN THE LOWER CHEHALIS RIVER VALLEY EXTENDING INTO GRAYS
HARBOR AT THIS TIME. EXPECT THE FOG TO DISSIPATE DURING THE NEXT
HOUR OR TWO. MEANWHILE...AN UPPER RIDGE WILL PREVAIL OVER THE
REGION THROUGH MON FOR DRY WEATHER WITH ABOVE NORMAL TEMPS.

THE LATEST GFS AND NAM SOLUTIONS STARTED THE MARINE PUSH MON
AFTERNOON OR EARLIER THAN FORECAST...SO THERE IS A POSSIBILITY
THAT THE COAST WILL BE COOLER ON MON. THERE IS ALSO A POSSIBILITY
THAT THE NEXT NAM AND GFS CYCLE WILL DELAY THE MARINE PUSH TIL MON
NIGHT.

.LONG TERM FROM THE PREV DISCUSSION...
THE UPPER RIDGE SHIFTS EAST OF THE CASCADES MONDAY NIGHT AS A
FRONTAL SYSTEM MOVES INTO THE OFFSHORE WATERS. IT APPEARS LIKELY
THAT A GOOD MARINE PUSH WILL BEGIN MONDAY NIGHT OR TUESDAY.

THE 06Z GFS AND 00Z ECMWF ARE A SLIGHTLY SLOWER IN MAKING THE
TRANSITION TO ONSHORE FLOW...AND THAT MAKES THE CLOUD AND
TEMPERATURE FORECAST FOR TUESDAY CHALLENGING. LATE APRIL MARINE
PUSHES AFTER A WARM SPELL CAN BE QUITE DRASTIC HERE IN WESTERN
WASHINGTON WITH 24 HOUR TEMPERATURE FALLS OF 15 TO 20 DEGREES NOT
OUT OF THE QUESTION. THE LATEST WRFGFS FROM THE UNIVERSITY OF
WASHINGTON SHOWS HIGHS IN SEATTLE ON TUESDAY AROUND 70 WHILE THE
NAM12 SHOWS HIGHS IN THE MID TO UPPER 50S. THE CURRENT FORECAST OF
MID 60S WILL BE RETAINED FOR NOW. SHOWER CHANCES DO NOT APPEAR LARGE
WITH THE FRONT OR THE PASSING UPPER TROUGH...GUIDANCE VALUES IN THE
CHANCE CATEGORY ARE SIMILAR TO THE CURRENT FORECAST.

AFTER TUESDAY...THE MODEL RUN-TO-RUN CONSISTENCY IS NOT GREAT WITH
THE 06Z GFS SHOWING WEAK SHORT WAVE RIDGING ON WED WHILE THE ECMWF
SHOWS A STRONG PUSH TUE NIGHT THROUGH THU FOLLOWED BY THE APPROACH
OF A DEEP UPPER TROUGH LATE IN THE WEEK. NO SIGNIFICANT CHANGES
WERE MADE TO THE LONG TERM FORECAST EARLY THIS MORNING. ALBRECHT

&&

.AVIATION...AN UPPER LEVEL RIDGE OVER THE PAC NW WILL GIVE CLEAR
SKIES AND A DRY STABLE AIR MASS OVER WRN WA THIS WEEKEND. THE FLOW
ALOFT IS NORTHWEST.

KSEA...CLEAR SKIES WITH A NORTHERLY BREEZE.

&&

.MARINE...FOR THE COASTAL WATERS THERE WILL BE AFTERNOON AND EVENING
NW WIND 15 TO 25 KT BETWEEN HIGH PRESSURE OFFSHORE AND THERMAL LOW
PRESSURE CENTERED OVER CALIF. ELSEWHERE...WINDS ARE NOT EXPECTED TO
EXCEED 20 KTS. A COLD FRONT WILL ARRIVE TUESDAY.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY IN EFFECT TIL 11 PM TONIGHT FOR THE
     COASTAL WATERS.

     SMALL CRAFT ADVISORY FOR ROUGH BAR IN EFFECT TIL 9 PM
     TONIGHT FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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





000
FXUS66 KSEW 181612
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
912 AM PDT SAT APR 18 2015

.SYNOPSIS...HIGH PRESSURE ALOFT WILL PREVAIL OVER THE REGION
THROUGH MONDAY FOR DRY WEATHER WITH ABOVE NORMAL TEMPERATURES.
UNSETTLED AND COOLER CONDITIONS ARE ANTICIPATED TUESDAY THROUGH
THE END OF NEXT WEEK.

&&

.SHORT TERM...
SKIES WERE MOSTLY SUNNY OVER THE CWA THIS MORNING. THERE WAS
PATCHY FOG IN THE LOWER CHEHALIS RIVER VALLEY EXTENDING INTO GRAYS
HARBOR AT THIS TIME. EXPECT THE FOG TO DISSIPATE DURING THE NEXT
HOUR OR TWO. MEANWHILE...AN UPPER RIDGE WILL PREVAIL OVER THE
REGION THROUGH MON FOR DRY WEATHER WITH ABOVE NORMAL TEMPS.

THE LATEST GFS AND NAM SOLUTIONS STARTED THE MARINE PUSH MON
AFTERNOON OR EARLIER THAN FORECAST...SO THERE IS A POSSIBILITY
THAT THE COAST WILL BE COOLER ON MON. THERE IS ALSO A POSSIBILITY
THAT THE NEXT NAM AND GFS CYCLE WILL DELAY THE MARINE PUSH TIL MON
NIGHT.

.LONG TERM FROM THE PREV DISCUSSION...
THE UPPER RIDGE SHIFTS EAST OF THE CASCADES MONDAY NIGHT AS A
FRONTAL SYSTEM MOVES INTO THE OFFSHORE WATERS. IT APPEARS LIKELY
THAT A GOOD MARINE PUSH WILL BEGIN MONDAY NIGHT OR TUESDAY.

THE 06Z GFS AND 00Z ECMWF ARE A SLIGHTLY SLOWER IN MAKING THE
TRANSITION TO ONSHORE FLOW...AND THAT MAKES THE CLOUD AND
TEMPERATURE FORECAST FOR TUESDAY CHALLENGING. LATE APRIL MARINE
PUSHES AFTER A WARM SPELL CAN BE QUITE DRASTIC HERE IN WESTERN
WASHINGTON WITH 24 HOUR TEMPERATURE FALLS OF 15 TO 20 DEGREES NOT
OUT OF THE QUESTION. THE LATEST WRFGFS FROM THE UNIVERSITY OF
WASHINGTON SHOWS HIGHS IN SEATTLE ON TUESDAY AROUND 70 WHILE THE
NAM12 SHOWS HIGHS IN THE MID TO UPPER 50S. THE CURRENT FORECAST OF
MID 60S WILL BE RETAINED FOR NOW. SHOWER CHANCES DO NOT APPEAR LARGE
WITH THE FRONT OR THE PASSING UPPER TROUGH...GUIDANCE VALUES IN THE
CHANCE CATEGORY ARE SIMILAR TO THE CURRENT FORECAST.

AFTER TUESDAY...THE MODEL RUN-TO-RUN CONSISTENCY IS NOT GREAT WITH
THE 06Z GFS SHOWING WEAK SHORT WAVE RIDGING ON WED WHILE THE ECMWF
SHOWS A STRONG PUSH TUE NIGHT THROUGH THU FOLLOWED BY THE APPROACH
OF A DEEP UPPER TROUGH LATE IN THE WEEK. NO SIGNIFICANT CHANGES
WERE MADE TO THE LONG TERM FORECAST EARLY THIS MORNING. ALBRECHT

&&

.AVIATION...AN UPPER LEVEL RIDGE OVER THE PAC NW WILL GIVE CLEAR
SKIES AND A DRY STABLE AIR MASS OVER WRN WA THIS WEEKEND. THE FLOW
ALOFT IS NORTHWEST.

KSEA...CLEAR SKIES WITH A NORTHERLY BREEZE.

&&

.MARINE...FOR THE COASTAL WATERS THERE WILL BE AFTERNOON AND EVENING
NW WIND 15 TO 25 KT BETWEEN HIGH PRESSURE OFFSHORE AND THERMAL LOW
PRESSURE CENTERED OVER CALIF. ELSEWHERE...WINDS ARE NOT EXPECTED TO
EXCEED 20 KTS. A COLD FRONT WILL ARRIVE TUESDAY.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY IN EFFECT TIL 11 PM TONIGHT FOR THE
     COASTAL WATERS.

     SMALL CRAFT ADVISORY FOR ROUGH BAR IN EFFECT TIL 9 PM
     TONIGHT FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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






000
FXUS66 KSEW 180959
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 AM PDT SAT APR 18 2015

.SYNOPSIS...HIGH PRESSURE AT THE SURFACE AND ALOFT IS CENTERED OVER
THE COASTAL WATERS. THE HIGH PRESSURE WILL GIVE DRY WEATHER TO THE
AREA THROUGH MONDAY AND TEMPERATURES WILL AVERAGE ABOVE NORMAL FOR
MID TO LATE APRIL. THE PATTERN IS EXPECTED TO CHANGE TO A CLOUDIER
AND COOLER ONE ON TUESDAY WITH A CHANCE OF SHOWERS AS A TROUGH OF
LOW PRESSURE ALOFT APPROACHES THE COAST AND LOW LEVEL FLOW BECOMES
ONSHORE.

&&

.SHORT TERM...A RIDGE OF HIGH PRESSURE AT THE SURFACE AND ALOFT IS
CENTERED AROUND 130W EARLY THIS MORNING. SKIES ACROSS THE REGION ARE
MOSTLY CLEAR WITH EXCEPTION TO A SMALL AREA TO THE SOUTHEAST OF THE
OLYMPICS AND A SMALL STRIP ON THE COAST...WHERE THERE ARE SOME
PATCHES OF LOW CLOUDS AND POSSIBLE FOG.

RUN AFTER RUN OF THE HRRR SHOWS THE DEVELOPMENT OF A RATHER LARGE
AREA OF FOG AND STRATUS ALONG THE IMMEDIATE WASHINGTON COAST AND
THROUGH THE STRAIT OF JUAN DE FUCA. BUT MULTISPECTRAL SATELLITE
IMAGES SO LITTLE OR NO FOG FORMING AT ALL. AS A RESULT...THE
FORECAST FOR THIS MORNING WILL BE LIMITED TO PATCHY LOW CLOUDS AND
FOG ALONG THE COAST AND THROUGH THE CHEHALIS GAP INTO THE NORMALLY
FOGGIER LOCATIONS OF THE SOUTH INTERIOR. FOG AND LOW CLOUDS THAT DO
DEVELOP WILL BE QUITE SHALLOW AND SHOULD BE GONE BY 10 AM.

THE OVERALL PATTERN TODAY THROUGH SUNDAY WILL CHANGE LITTLE.
TEMPERATURES ALOFT WARM 1-2C TODAY AND SUNDAY. EXPECT SURFACE
TEMPERATURES TO WARM SIMILARLY WITH HIGHS TODAY IN THE MID 60S
TO MID 70S IN THE INTERIOR AND HIGHS ON SUNDAY ANOTHER 1-3 DEGREES
WARMER. CLEAR SKIES AND DRY CONDITIONS WILL ALLOW TEMPERATURES
TONIGHT TO FALL INTO THE UPPER 30S TO MID 40S.

THE OFFSHORE UPPER RIDGE WILL MOVE INLAND ON MONDAY...AND MONDAY
SHOULD BE THE WARMEST DAY OF THIS WARM SPELL. AREAS FROM EVERETT
SOUTHWARD SHOULD SEE LOWER TO MID 70S ON MONDAY WITH PLENTY OF
SUNSHINE. ALBRECHT

.LONG TERM...THE UPPER RIDGE SHIFTS EAST OF THE CASCADES MONDAY
NIGHT AS A FRONTAL SYSTEM MOVES INTO THE OFFSHORE WATERS. IT APPEARS
LIKELY THAT A GOOD MARINE PUSH WILL BEGIN MONDAY NIGHT OR TUESDAY.

THE 06Z GFS AND 00Z ECMWF ARE A SLIGHTLY SLOWER IN MAKING THE
TRANSITION TO ONSHORE FLOW...AND THAT MAKES THE CLOUD AND
TEMPERATURE FORECAST FOR TUESDAY CHALLENGING. LATE APRIL MARINE
PUSHES AFTER A WARM SPELL CAN BE QUITE DRASTIC HERE IN WESTERN
WASHINGTON WITH 24 HOUR TEMPERATURE FALLS OF 15 TO 20 DEGREES NOT
OUT OF THE QUESTION. THE LATEST WRFGFS FROM THE UNIVERSITY OF
WASHINGTON SHOWS HIGHS IN SEATTLE ON TUESDAY AROUND 70 WHILE THE
NAM12 SHOWS HIGHS IN THE MID TO UPPER 50S. THE CURRENT FORECAST OF
MID 60S WILL BE RETAINED FOR NOW. SHOWER CHANCES DO NOT APPEAR LARGE
WITH THE FRONT OR THE PASSING UPPER TROUGH...GUIDANCE VALUES IN THE
CHANCE CATEGORY ARE SIMILAR TO THE CURRENT FORECAST.

AFTER TUESDAY...THE MODEL RUN-TO-RUN CONSISTENCY IS NOT GREAT WITH
THE 06Z GFS SHOWING WEAK SHORT WAVE RIDGING ON WED WHILE THE ECMWF
SHOWS A STRONG PUSH TUE NIGHT THROUGH THU FOLLOWED BY THE APPROACH
OF A DEEP UPPER TROUGH LATE IN THE WEEK. NO SIGNIFICANT CHANGES
WERE MADE TO THE LONG TERM FORECAST EARLY THIS MORNING. ALBRECHT

&&

.AVIATION...AN UPPER LEVEL RIDGE OVER THE PAC NW WILL LEAD TO DRY
AND STABLE WEATHER ACROSS WESTERN WA TODAY. THE FLOW ALOFT IS
NORTHWESTERLY. VFR CONDITIONS ARE EXPECTED...ALTHOUGH MAY SEE PATCHY
SHALLOW FOG THIS MORNING IN THE SOUTH SOUND AND COAST. OTHERWISE
SKIES WILL REMAIN CLEAR. 33

KSEA...VFR CONDITIONS TODAY. EXPECT N WINDS TO 10 KT. 33

&&

.MARINE...LOW PRESSURE ALONG THE COAST WILL MAINTAIN NORTHERLY FLOW
ACROSS WESTERN WA TODAY. MODELS CONTINUE TO SHOW NW WINDS OF 15 TO
25 KT OVER THE COASTAL WATERS AND STRAIT OF GEORGIA - SMALL CRAFT
ADVISORIES REMAIN IN EFFECT. EXPECT EASTERLY WINDS THROUGH THE
STRAIT OF JUAN DE FUCA...BECOMING WEST 10 TO 20 KT THIS AFTERNOON.
NORTHERLY FLOW WILL CONTINUE THROUGH SUNDAY AND MONDAY. ONSHORE FLOW
WILL INCREASE ON TUESDAY AS A COLD FRONT MOVES INLAND. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COASTAL WATERS...NORTHERN INLAND
      WATERS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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












000
FXUS66 KSEW 180959
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 AM PDT SAT APR 18 2015

.SYNOPSIS...HIGH PRESSURE AT THE SURFACE AND ALOFT IS CENTERED OVER
THE COASTAL WATERS. THE HIGH PRESSURE WILL GIVE DRY WEATHER TO THE
AREA THROUGH MONDAY AND TEMPERATURES WILL AVERAGE ABOVE NORMAL FOR
MID TO LATE APRIL. THE PATTERN IS EXPECTED TO CHANGE TO A CLOUDIER
AND COOLER ONE ON TUESDAY WITH A CHANCE OF SHOWERS AS A TROUGH OF
LOW PRESSURE ALOFT APPROACHES THE COAST AND LOW LEVEL FLOW BECOMES
ONSHORE.

&&

.SHORT TERM...A RIDGE OF HIGH PRESSURE AT THE SURFACE AND ALOFT IS
CENTERED AROUND 130W EARLY THIS MORNING. SKIES ACROSS THE REGION ARE
MOSTLY CLEAR WITH EXCEPTION TO A SMALL AREA TO THE SOUTHEAST OF THE
OLYMPICS AND A SMALL STRIP ON THE COAST...WHERE THERE ARE SOME
PATCHES OF LOW CLOUDS AND POSSIBLE FOG.

RUN AFTER RUN OF THE HRRR SHOWS THE DEVELOPMENT OF A RATHER LARGE
AREA OF FOG AND STRATUS ALONG THE IMMEDIATE WASHINGTON COAST AND
THROUGH THE STRAIT OF JUAN DE FUCA. BUT MULTISPECTRAL SATELLITE
IMAGES SO LITTLE OR NO FOG FORMING AT ALL. AS A RESULT...THE
FORECAST FOR THIS MORNING WILL BE LIMITED TO PATCHY LOW CLOUDS AND
FOG ALONG THE COAST AND THROUGH THE CHEHALIS GAP INTO THE NORMALLY
FOGGIER LOCATIONS OF THE SOUTH INTERIOR. FOG AND LOW CLOUDS THAT DO
DEVELOP WILL BE QUITE SHALLOW AND SHOULD BE GONE BY 10 AM.

THE OVERALL PATTERN TODAY THROUGH SUNDAY WILL CHANGE LITTLE.
TEMPERATURES ALOFT WARM 1-2C TODAY AND SUNDAY. EXPECT SURFACE
TEMPERATURES TO WARM SIMILARLY WITH HIGHS TODAY IN THE MID 60S
TO MID 70S IN THE INTERIOR AND HIGHS ON SUNDAY ANOTHER 1-3 DEGREES
WARMER. CLEAR SKIES AND DRY CONDITIONS WILL ALLOW TEMPERATURES
TONIGHT TO FALL INTO THE UPPER 30S TO MID 40S.

THE OFFSHORE UPPER RIDGE WILL MOVE INLAND ON MONDAY...AND MONDAY
SHOULD BE THE WARMEST DAY OF THIS WARM SPELL. AREAS FROM EVERETT
SOUTHWARD SHOULD SEE LOWER TO MID 70S ON MONDAY WITH PLENTY OF
SUNSHINE. ALBRECHT

.LONG TERM...THE UPPER RIDGE SHIFTS EAST OF THE CASCADES MONDAY
NIGHT AS A FRONTAL SYSTEM MOVES INTO THE OFFSHORE WATERS. IT APPEARS
LIKELY THAT A GOOD MARINE PUSH WILL BEGIN MONDAY NIGHT OR TUESDAY.

THE 06Z GFS AND 00Z ECMWF ARE A SLIGHTLY SLOWER IN MAKING THE
TRANSITION TO ONSHORE FLOW...AND THAT MAKES THE CLOUD AND
TEMPERATURE FORECAST FOR TUESDAY CHALLENGING. LATE APRIL MARINE
PUSHES AFTER A WARM SPELL CAN BE QUITE DRASTIC HERE IN WESTERN
WASHINGTON WITH 24 HOUR TEMPERATURE FALLS OF 15 TO 20 DEGREES NOT
OUT OF THE QUESTION. THE LATEST WRFGFS FROM THE UNIVERSITY OF
WASHINGTON SHOWS HIGHS IN SEATTLE ON TUESDAY AROUND 70 WHILE THE
NAM12 SHOWS HIGHS IN THE MID TO UPPER 50S. THE CURRENT FORECAST OF
MID 60S WILL BE RETAINED FOR NOW. SHOWER CHANCES DO NOT APPEAR LARGE
WITH THE FRONT OR THE PASSING UPPER TROUGH...GUIDANCE VALUES IN THE
CHANCE CATEGORY ARE SIMILAR TO THE CURRENT FORECAST.

AFTER TUESDAY...THE MODEL RUN-TO-RUN CONSISTENCY IS NOT GREAT WITH
THE 06Z GFS SHOWING WEAK SHORT WAVE RIDGING ON WED WHILE THE ECMWF
SHOWS A STRONG PUSH TUE NIGHT THROUGH THU FOLLOWED BY THE APPROACH
OF A DEEP UPPER TROUGH LATE IN THE WEEK. NO SIGNIFICANT CHANGES
WERE MADE TO THE LONG TERM FORECAST EARLY THIS MORNING. ALBRECHT

&&

.AVIATION...AN UPPER LEVEL RIDGE OVER THE PAC NW WILL LEAD TO DRY
AND STABLE WEATHER ACROSS WESTERN WA TODAY. THE FLOW ALOFT IS
NORTHWESTERLY. VFR CONDITIONS ARE EXPECTED...ALTHOUGH MAY SEE PATCHY
SHALLOW FOG THIS MORNING IN THE SOUTH SOUND AND COAST. OTHERWISE
SKIES WILL REMAIN CLEAR. 33

KSEA...VFR CONDITIONS TODAY. EXPECT N WINDS TO 10 KT. 33

&&

.MARINE...LOW PRESSURE ALONG THE COAST WILL MAINTAIN NORTHERLY FLOW
ACROSS WESTERN WA TODAY. MODELS CONTINUE TO SHOW NW WINDS OF 15 TO
25 KT OVER THE COASTAL WATERS AND STRAIT OF GEORGIA - SMALL CRAFT
ADVISORIES REMAIN IN EFFECT. EXPECT EASTERLY WINDS THROUGH THE
STRAIT OF JUAN DE FUCA...BECOMING WEST 10 TO 20 KT THIS AFTERNOON.
NORTHERLY FLOW WILL CONTINUE THROUGH SUNDAY AND MONDAY. ONSHORE FLOW
WILL INCREASE ON TUESDAY AS A COLD FRONT MOVES INLAND. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COASTAL WATERS...NORTHERN INLAND
      WATERS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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











000
FXUS66 KSEW 180433
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
935 PM PDT FRI APR 17 2015

.SYNOPSIS...HIGH PRESSURE ALOFT WILL PREVAIL OVER THE REGION
THROUGH MONDAY FOR DRY WEATHER WITH ABOVE NORMAL TEMPERATURES.
ANTICIPATE COOLER AND UNSETTLED CONDITIONS TUESDAY THROUGH THE
END OF NEXT WEEK.

&&

.SHORT TERM...SATELLITE IMAGERY SHOWS A SMALL AREA OF SC OVER THE
CENTRAL SOUND THIS EVENING. STRATUS ALONG THE CENTRAL COAST EARLIER
TODAY HAS MOVED SOUTH AND OFFSHORE THIS EVENING. SMOKE FROM FIRES IN
SIBERIA ALSO OVER THE AREA THIS EVENING. TEMPERATURES AT 9 PM WERE
IN THE UPPER 40S TO NEAR 60.

UPPER LEVEL RIDGE BUILDING OFFSHORE OVERNIGHT INTO SATURDAY MORNING
WITH WHAT LITTLE CLOUD COVER THAT IS OVER THE AREA THIS EVENING
DISSIPATING. NORTHERLY SURFACE GRADIENTS NOT STRONG ENOUGH TO
COMPLETELY ELIMINATE THE POSSIBILITY OF FOG IN THE FOG PRONE
LOCATIONS LIKE THE SOUTHWEST INTERIOR EARLY SATURDAY MORNING. LOWS
OVERNIGHT WILL BE IN THE UPPER 30S AND 40S.

SUNNY WEATHER IN STORE FOR SATURDAY WITH THE UPPER LEVEL RIDGE OVER
THE AREA. PATCHY MORNING FOG WILL BE SHALLOW AND BURN OFF QUICKLY.
TEMPERATURES ALOFT DO NOT WARM UP VERY MUCH ON SATURDAY...850 MB
TEMPS GO FROM AROUND PLUS 6 TO PLUS 8C...WITH THE UPPER LEVEL RIDGE
AXIS STILL OFFSHORE BY 00Z SUNDAY. THIS COMBINED WITH THE
CONTINUATION OF THE NORTHWESTERLY SURFACE GRADIENTS WILL KEEP HIGHS
ON SATURDAY JUST A COUPLE OF DEGREES WARMER THAT FRIDAY WITH 60S AND
LOWER 70S FORECAST.

LITTLE CHANGE IN THE PATTERN SATURDAY NIGHT AND SUNDAY WITH THE
UPPER LEVEL RIDGE AXIS REMAINING OFFSHORE AND THE SURFACE GRADIENTS
REMAINING NORTHWESTERLY. TEMPERATURES ALOFT CONTINUING WITH THE
GRADUAL WARMING TREND WITH 850 MB TEMPS NEAR PLUS 10C BY 00Z MONDAY.
WITH A COUPLE OF DEGREES MORE OF WARMING THE WARMEST LOCATIONS WILL
GET INTO THE MID 70S ON SUNDAY WITH 60S AND LOWER 70S ELSEWHERE.

UPPER LEVEL RIDGE AXIS SHIFTING INLAND ON MONDAY WITH THE
NORTHWESTERLY SURFACE GRADIENTS WEAKENING. TEMPERATURES ALOFT SHOW
LITTLE CHANGE VERSUS SUNDAY. FOR NOW A PERSISTENCE FORECAST LOOKS
GOOD FOR MONDAY WITH THE POSSIBILITY OF A COUPLE MORE DEGREES OF
WARMING IF THE AFTERNOON NORTHERLIES ARE SLOW TO KICK IN. CURRENT
FORECAST ON TRACK. NO UPDATES THIS EVENING. FELTON

.LONG TERM...PREVIOUS DISCUSSION FOLLOWS.
THE MEDIUM RANGE SOLUTIONS WERE IN MORE OR LESS AGREEMENT THAT AN
UPPER TROF WILL BECOME THE DOMINANT FEATURE OVER THE WESTERN USA.
THE PRIMARY DIFFERENCE BETWEEN THE MODELS WERE IN THE DETAILS.
ANTICIPATE COOLER AND UNSETTLED CONDITIONS DURING THIS PERIOD.

&&

.AVIATION...AN UPPER LEVEL RIDGE OVER THE NE PAC WILL NUDGE EAST
INTO WESTERN WA FOR DRY AND STABLE WEATHER. THE FLOW ALOFT IS
NORTHWESTERLY. VFR CONDITIONS ARE EXPECTED...ALTHOUGH MAY SEE PATCHY
SHALLOW FOG SATURDAY MORNING IN THE SOUTH SOUND AND COAST.
OTHERWISE...HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH SATURDAY
FOR CLEAR SKIES. 33

KSEA...VFR CONDITIONS WILL CONTINUE TONIGHT. SCT050 CLOUDS WILL EXIT
THIS EVENING FOR CLEAR SKIES. EXPECT N/NE WINDS TO 10 KT. 33

&&

.MARINE...ONSHORE FLOW WILL EASE ACROSS WESTERN WA TONIGHT. GALES
HAVE ENDED IN THE STRAIT BUT WILL CONTINUE TO SEE SMALL CRAFT
ADVISORY WINDS THROUGH AT LEAST MIDNIGHT TONIGHT. MODELS CONTINUE TO
SHOW NW WINDS OF 15 TO 25 KT THROUGH THE STRAIT OF GEORGIA AND A
SMALL CRAFT ADVISORY IS IN EFFECT FOR THE NORTHERN INLAND WATERS.
LOW PRESSURE ALONG THE COAST WILL MAINTAIN NORTHERLY FLOW SATURDAY
AND SUNDAY. OFFSHORE FLOW WILL CONTINUE THROUGH MONDAY. THE NEXT
FRONT WILL ARRIVE TUESDAY AFTERNOON OR EVENING. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COASTAL WATERS...STRAIT OF JUAN DE
     FUCA...NORTHERN INLAND WATERS...ADMIRALTY INLET.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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









000
FXUS66 KSEW 180433
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
935 PM PDT FRI APR 17 2015

.SYNOPSIS...HIGH PRESSURE ALOFT WILL PREVAIL OVER THE REGION
THROUGH MONDAY FOR DRY WEATHER WITH ABOVE NORMAL TEMPERATURES.
ANTICIPATE COOLER AND UNSETTLED CONDITIONS TUESDAY THROUGH THE
END OF NEXT WEEK.

&&

.SHORT TERM...SATELLITE IMAGERY SHOWS A SMALL AREA OF SC OVER THE
CENTRAL SOUND THIS EVENING. STRATUS ALONG THE CENTRAL COAST EARLIER
TODAY HAS MOVED SOUTH AND OFFSHORE THIS EVENING. SMOKE FROM FIRES IN
SIBERIA ALSO OVER THE AREA THIS EVENING. TEMPERATURES AT 9 PM WERE
IN THE UPPER 40S TO NEAR 60.

UPPER LEVEL RIDGE BUILDING OFFSHORE OVERNIGHT INTO SATURDAY MORNING
WITH WHAT LITTLE CLOUD COVER THAT IS OVER THE AREA THIS EVENING
DISSIPATING. NORTHERLY SURFACE GRADIENTS NOT STRONG ENOUGH TO
COMPLETELY ELIMINATE THE POSSIBILITY OF FOG IN THE FOG PRONE
LOCATIONS LIKE THE SOUTHWEST INTERIOR EARLY SATURDAY MORNING. LOWS
OVERNIGHT WILL BE IN THE UPPER 30S AND 40S.

SUNNY WEATHER IN STORE FOR SATURDAY WITH THE UPPER LEVEL RIDGE OVER
THE AREA. PATCHY MORNING FOG WILL BE SHALLOW AND BURN OFF QUICKLY.
TEMPERATURES ALOFT DO NOT WARM UP VERY MUCH ON SATURDAY...850 MB
TEMPS GO FROM AROUND PLUS 6 TO PLUS 8C...WITH THE UPPER LEVEL RIDGE
AXIS STILL OFFSHORE BY 00Z SUNDAY. THIS COMBINED WITH THE
CONTINUATION OF THE NORTHWESTERLY SURFACE GRADIENTS WILL KEEP HIGHS
ON SATURDAY JUST A COUPLE OF DEGREES WARMER THAT FRIDAY WITH 60S AND
LOWER 70S FORECAST.

LITTLE CHANGE IN THE PATTERN SATURDAY NIGHT AND SUNDAY WITH THE
UPPER LEVEL RIDGE AXIS REMAINING OFFSHORE AND THE SURFACE GRADIENTS
REMAINING NORTHWESTERLY. TEMPERATURES ALOFT CONTINUING WITH THE
GRADUAL WARMING TREND WITH 850 MB TEMPS NEAR PLUS 10C BY 00Z MONDAY.
WITH A COUPLE OF DEGREES MORE OF WARMING THE WARMEST LOCATIONS WILL
GET INTO THE MID 70S ON SUNDAY WITH 60S AND LOWER 70S ELSEWHERE.

UPPER LEVEL RIDGE AXIS SHIFTING INLAND ON MONDAY WITH THE
NORTHWESTERLY SURFACE GRADIENTS WEAKENING. TEMPERATURES ALOFT SHOW
LITTLE CHANGE VERSUS SUNDAY. FOR NOW A PERSISTENCE FORECAST LOOKS
GOOD FOR MONDAY WITH THE POSSIBILITY OF A COUPLE MORE DEGREES OF
WARMING IF THE AFTERNOON NORTHERLIES ARE SLOW TO KICK IN. CURRENT
FORECAST ON TRACK. NO UPDATES THIS EVENING. FELTON

.LONG TERM...PREVIOUS DISCUSSION FOLLOWS.
THE MEDIUM RANGE SOLUTIONS WERE IN MORE OR LESS AGREEMENT THAT AN
UPPER TROF WILL BECOME THE DOMINANT FEATURE OVER THE WESTERN USA.
THE PRIMARY DIFFERENCE BETWEEN THE MODELS WERE IN THE DETAILS.
ANTICIPATE COOLER AND UNSETTLED CONDITIONS DURING THIS PERIOD.

&&

.AVIATION...AN UPPER LEVEL RIDGE OVER THE NE PAC WILL NUDGE EAST
INTO WESTERN WA FOR DRY AND STABLE WEATHER. THE FLOW ALOFT IS
NORTHWESTERLY. VFR CONDITIONS ARE EXPECTED...ALTHOUGH MAY SEE PATCHY
SHALLOW FOG SATURDAY MORNING IN THE SOUTH SOUND AND COAST.
OTHERWISE...HIGH PRESSURE WILL REMAIN IN CONTROL THROUGH SATURDAY
FOR CLEAR SKIES. 33

KSEA...VFR CONDITIONS WILL CONTINUE TONIGHT. SCT050 CLOUDS WILL EXIT
THIS EVENING FOR CLEAR SKIES. EXPECT N/NE WINDS TO 10 KT. 33

&&

.MARINE...ONSHORE FLOW WILL EASE ACROSS WESTERN WA TONIGHT. GALES
HAVE ENDED IN THE STRAIT BUT WILL CONTINUE TO SEE SMALL CRAFT
ADVISORY WINDS THROUGH AT LEAST MIDNIGHT TONIGHT. MODELS CONTINUE TO
SHOW NW WINDS OF 15 TO 25 KT THROUGH THE STRAIT OF GEORGIA AND A
SMALL CRAFT ADVISORY IS IN EFFECT FOR THE NORTHERN INLAND WATERS.
LOW PRESSURE ALONG THE COAST WILL MAINTAIN NORTHERLY FLOW SATURDAY
AND SUNDAY. OFFSHORE FLOW WILL CONTINUE THROUGH MONDAY. THE NEXT
FRONT WILL ARRIVE TUESDAY AFTERNOON OR EVENING. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COASTAL WATERS...STRAIT OF JUAN DE
     FUCA...NORTHERN INLAND WATERS...ADMIRALTY INLET.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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








000
FXUS66 KSEW 172149
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
249 PM PDT FRI APR 17 2015

.SYNOPSIS...HIGH PRESSURE ALOFT WILL PREVAIL OVER THE REGION
THROUGH MONDAY FOR DRY WEATHER WITH ABOVE NORMAL TEMPERATURES.
ANTICIPATE COOLER AND UNSETTLED CONDITIONS TUESDAY THROUGH THE
END OF NEXT WEEK.

&&

.SHORT TERM...
AN UPPER RIDGE WILL PREVAIL OVER THE REGION THROUGH MON. THIS
COMBINED WITH LIGHT LOW LEVEL NORTHERLY FLOW WILL RESULT IN DRY
WEATHER WITH ABOVE NORMAL TEMPERATURES. THERE WILL BE AREAS OF LOW
CLOUDS AND/OR STRATUS TONIGHT THROUGH SATURDAY MORNING...OTHERWISE
LOOK FOR MOSTLY CLEAR SKIES. HIGHS ARE FORECAST TO CLIMB INTO THE
70S OVER PARTS OF THE INTERIOR SUNDAY AND MONDAY. THE AXIS OF THE
UPPER RIDGE WILL SHIFT EAST OF THE AREA MON AFTERNOON AND THIS
WILL INITIATE AN ONSHORE PUSH.

.LONG TERM...
THE MEDIUM RANGE SOLUTIONS WERE IN MORE OR LESS AGREEMENT THAT AN
UPPER TROF WILL BECOME THE DOMINANT FEATURE OVER THE WESTERN USA.
THE PRIMARY DIFFERENCE BETWEEN THE MODELS WERE IN THE DETAILS.
ANTICIPATE COOLER AND UNSETTLED CONDITIONS DURING THIS PERIOD.

&&

.AVIATION...A PATCH OF MARINE STRATUS REACHED THE NORTH COAST EARLY
THIS AFTERNOON BUT MOST OF WRN WA IS CLEAR. THERE IS STRONG SURFACE
HIGH PRESSURE OFFSHORE WITH LOWER PRESSURE INLAND. THERE IS ALSO
THERMALLY INDUCED LOW PRESSURE OVER CALIF THAT WILL NUDGE UP THE SRN
OREGON COAST THIS WEEKEND. NW FLOW ALOFT. A FEW AREAS OF MORNING LOW
CLOUDS AND PATCHY FOG AROUND DAYBREAK SATURDAY WILL QUICKLY GIVE WAY
TO SUNSHINE.

KSEA...SOME MID LEVEL CLOUDS FOR AWHILE TODAY AS AN UPPER TROUGH
MOVING THROUGH B.C. CLIPS WRN WA. THE NLY BREEZE SHOULD PICK UP THIS
AFTERNOON AND EVENING AS HIGH PRESSURE BUILDS IN. WE MAY SEE A FEW
HOURS OF LOW CLOUDS AND PATCHY FOG AROUND DAYBREAK SATURDAY.

&&

.MARINE...THERE IS STRONG SURFACE HIGH PRESSURE OFFSHORE AND LOWER
PRESSURE INLAND. THERMALLY INDUCED LOWER PRESSURE OVER CALIF WILL
EXTEND SOMEWHAT NORTH ALONG THE OREGON COAST THIS WEEKEND...AND THAT
MAY CONTINUE TO DRIVE A BRISK NW WIND ALONG THE COAST...ESPECIALLY
IN THE AFTERNOON AND EVENING HOURS. THE UPPER RIDGE WILL GIVE WAY
MONDAY AND THE NEXT FRONT WILL ARRIVE BY NEXT TUESDAY.

&&

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

     SMALL CRAFT ADVISORY FOR ROUGH BAR IN EFFECT TIL 5 AM
     SATURDAY FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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






000
FXUS66 KSEW 172149
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
249 PM PDT FRI APR 17 2015

.SYNOPSIS...HIGH PRESSURE ALOFT WILL PREVAIL OVER THE REGION
THROUGH MONDAY FOR DRY WEATHER WITH ABOVE NORMAL TEMPERATURES.
ANTICIPATE COOLER AND UNSETTLED CONDITIONS TUESDAY THROUGH THE
END OF NEXT WEEK.

&&

.SHORT TERM...
AN UPPER RIDGE WILL PREVAIL OVER THE REGION THROUGH MON. THIS
COMBINED WITH LIGHT LOW LEVEL NORTHERLY FLOW WILL RESULT IN DRY
WEATHER WITH ABOVE NORMAL TEMPERATURES. THERE WILL BE AREAS OF LOW
CLOUDS AND/OR STRATUS TONIGHT THROUGH SATURDAY MORNING...OTHERWISE
LOOK FOR MOSTLY CLEAR SKIES. HIGHS ARE FORECAST TO CLIMB INTO THE
70S OVER PARTS OF THE INTERIOR SUNDAY AND MONDAY. THE AXIS OF THE
UPPER RIDGE WILL SHIFT EAST OF THE AREA MON AFTERNOON AND THIS
WILL INITIATE AN ONSHORE PUSH.

.LONG TERM...
THE MEDIUM RANGE SOLUTIONS WERE IN MORE OR LESS AGREEMENT THAT AN
UPPER TROF WILL BECOME THE DOMINANT FEATURE OVER THE WESTERN USA.
THE PRIMARY DIFFERENCE BETWEEN THE MODELS WERE IN THE DETAILS.
ANTICIPATE COOLER AND UNSETTLED CONDITIONS DURING THIS PERIOD.

&&

.AVIATION...A PATCH OF MARINE STRATUS REACHED THE NORTH COAST EARLY
THIS AFTERNOON BUT MOST OF WRN WA IS CLEAR. THERE IS STRONG SURFACE
HIGH PRESSURE OFFSHORE WITH LOWER PRESSURE INLAND. THERE IS ALSO
THERMALLY INDUCED LOW PRESSURE OVER CALIF THAT WILL NUDGE UP THE SRN
OREGON COAST THIS WEEKEND. NW FLOW ALOFT. A FEW AREAS OF MORNING LOW
CLOUDS AND PATCHY FOG AROUND DAYBREAK SATURDAY WILL QUICKLY GIVE WAY
TO SUNSHINE.

KSEA...SOME MID LEVEL CLOUDS FOR AWHILE TODAY AS AN UPPER TROUGH
MOVING THROUGH B.C. CLIPS WRN WA. THE NLY BREEZE SHOULD PICK UP THIS
AFTERNOON AND EVENING AS HIGH PRESSURE BUILDS IN. WE MAY SEE A FEW
HOURS OF LOW CLOUDS AND PATCHY FOG AROUND DAYBREAK SATURDAY.

&&

.MARINE...THERE IS STRONG SURFACE HIGH PRESSURE OFFSHORE AND LOWER
PRESSURE INLAND. THERMALLY INDUCED LOWER PRESSURE OVER CALIF WILL
EXTEND SOMEWHAT NORTH ALONG THE OREGON COAST THIS WEEKEND...AND THAT
MAY CONTINUE TO DRIVE A BRISK NW WIND ALONG THE COAST...ESPECIALLY
IN THE AFTERNOON AND EVENING HOURS. THE UPPER RIDGE WILL GIVE WAY
MONDAY AND THE NEXT FRONT WILL ARRIVE BY NEXT TUESDAY.

&&

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

     SMALL CRAFT ADVISORY FOR ROUGH BAR IN EFFECT TIL 5 AM
     SATURDAY FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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





000
FXUS66 KSEW 172149
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
249 PM PDT FRI APR 17 2015

.SYNOPSIS...HIGH PRESSURE ALOFT WILL PREVAIL OVER THE REGION
THROUGH MONDAY FOR DRY WEATHER WITH ABOVE NORMAL TEMPERATURES.
ANTICIPATE COOLER AND UNSETTLED CONDITIONS TUESDAY THROUGH THE
END OF NEXT WEEK.

&&

.SHORT TERM...
AN UPPER RIDGE WILL PREVAIL OVER THE REGION THROUGH MON. THIS
COMBINED WITH LIGHT LOW LEVEL NORTHERLY FLOW WILL RESULT IN DRY
WEATHER WITH ABOVE NORMAL TEMPERATURES. THERE WILL BE AREAS OF LOW
CLOUDS AND/OR STRATUS TONIGHT THROUGH SATURDAY MORNING...OTHERWISE
LOOK FOR MOSTLY CLEAR SKIES. HIGHS ARE FORECAST TO CLIMB INTO THE
70S OVER PARTS OF THE INTERIOR SUNDAY AND MONDAY. THE AXIS OF THE
UPPER RIDGE WILL SHIFT EAST OF THE AREA MON AFTERNOON AND THIS
WILL INITIATE AN ONSHORE PUSH.

.LONG TERM...
THE MEDIUM RANGE SOLUTIONS WERE IN MORE OR LESS AGREEMENT THAT AN
UPPER TROF WILL BECOME THE DOMINANT FEATURE OVER THE WESTERN USA.
THE PRIMARY DIFFERENCE BETWEEN THE MODELS WERE IN THE DETAILS.
ANTICIPATE COOLER AND UNSETTLED CONDITIONS DURING THIS PERIOD.

&&

.AVIATION...A PATCH OF MARINE STRATUS REACHED THE NORTH COAST EARLY
THIS AFTERNOON BUT MOST OF WRN WA IS CLEAR. THERE IS STRONG SURFACE
HIGH PRESSURE OFFSHORE WITH LOWER PRESSURE INLAND. THERE IS ALSO
THERMALLY INDUCED LOW PRESSURE OVER CALIF THAT WILL NUDGE UP THE SRN
OREGON COAST THIS WEEKEND. NW FLOW ALOFT. A FEW AREAS OF MORNING LOW
CLOUDS AND PATCHY FOG AROUND DAYBREAK SATURDAY WILL QUICKLY GIVE WAY
TO SUNSHINE.

KSEA...SOME MID LEVEL CLOUDS FOR AWHILE TODAY AS AN UPPER TROUGH
MOVING THROUGH B.C. CLIPS WRN WA. THE NLY BREEZE SHOULD PICK UP THIS
AFTERNOON AND EVENING AS HIGH PRESSURE BUILDS IN. WE MAY SEE A FEW
HOURS OF LOW CLOUDS AND PATCHY FOG AROUND DAYBREAK SATURDAY.

&&

.MARINE...THERE IS STRONG SURFACE HIGH PRESSURE OFFSHORE AND LOWER
PRESSURE INLAND. THERMALLY INDUCED LOWER PRESSURE OVER CALIF WILL
EXTEND SOMEWHAT NORTH ALONG THE OREGON COAST THIS WEEKEND...AND THAT
MAY CONTINUE TO DRIVE A BRISK NW WIND ALONG THE COAST...ESPECIALLY
IN THE AFTERNOON AND EVENING HOURS. THE UPPER RIDGE WILL GIVE WAY
MONDAY AND THE NEXT FRONT WILL ARRIVE BY NEXT TUESDAY.

&&

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

     SMALL CRAFT ADVISORY FOR ROUGH BAR IN EFFECT TIL 5 AM
     SATURDAY FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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






000
FXUS66 KSEW 172149
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
249 PM PDT FRI APR 17 2015

.SYNOPSIS...HIGH PRESSURE ALOFT WILL PREVAIL OVER THE REGION
THROUGH MONDAY FOR DRY WEATHER WITH ABOVE NORMAL TEMPERATURES.
ANTICIPATE COOLER AND UNSETTLED CONDITIONS TUESDAY THROUGH THE
END OF NEXT WEEK.

&&

.SHORT TERM...
AN UPPER RIDGE WILL PREVAIL OVER THE REGION THROUGH MON. THIS
COMBINED WITH LIGHT LOW LEVEL NORTHERLY FLOW WILL RESULT IN DRY
WEATHER WITH ABOVE NORMAL TEMPERATURES. THERE WILL BE AREAS OF LOW
CLOUDS AND/OR STRATUS TONIGHT THROUGH SATURDAY MORNING...OTHERWISE
LOOK FOR MOSTLY CLEAR SKIES. HIGHS ARE FORECAST TO CLIMB INTO THE
70S OVER PARTS OF THE INTERIOR SUNDAY AND MONDAY. THE AXIS OF THE
UPPER RIDGE WILL SHIFT EAST OF THE AREA MON AFTERNOON AND THIS
WILL INITIATE AN ONSHORE PUSH.

.LONG TERM...
THE MEDIUM RANGE SOLUTIONS WERE IN MORE OR LESS AGREEMENT THAT AN
UPPER TROF WILL BECOME THE DOMINANT FEATURE OVER THE WESTERN USA.
THE PRIMARY DIFFERENCE BETWEEN THE MODELS WERE IN THE DETAILS.
ANTICIPATE COOLER AND UNSETTLED CONDITIONS DURING THIS PERIOD.

&&

.AVIATION...A PATCH OF MARINE STRATUS REACHED THE NORTH COAST EARLY
THIS AFTERNOON BUT MOST OF WRN WA IS CLEAR. THERE IS STRONG SURFACE
HIGH PRESSURE OFFSHORE WITH LOWER PRESSURE INLAND. THERE IS ALSO
THERMALLY INDUCED LOW PRESSURE OVER CALIF THAT WILL NUDGE UP THE SRN
OREGON COAST THIS WEEKEND. NW FLOW ALOFT. A FEW AREAS OF MORNING LOW
CLOUDS AND PATCHY FOG AROUND DAYBREAK SATURDAY WILL QUICKLY GIVE WAY
TO SUNSHINE.

KSEA...SOME MID LEVEL CLOUDS FOR AWHILE TODAY AS AN UPPER TROUGH
MOVING THROUGH B.C. CLIPS WRN WA. THE NLY BREEZE SHOULD PICK UP THIS
AFTERNOON AND EVENING AS HIGH PRESSURE BUILDS IN. WE MAY SEE A FEW
HOURS OF LOW CLOUDS AND PATCHY FOG AROUND DAYBREAK SATURDAY.

&&

.MARINE...THERE IS STRONG SURFACE HIGH PRESSURE OFFSHORE AND LOWER
PRESSURE INLAND. THERMALLY INDUCED LOWER PRESSURE OVER CALIF WILL
EXTEND SOMEWHAT NORTH ALONG THE OREGON COAST THIS WEEKEND...AND THAT
MAY CONTINUE TO DRIVE A BRISK NW WIND ALONG THE COAST...ESPECIALLY
IN THE AFTERNOON AND EVENING HOURS. THE UPPER RIDGE WILL GIVE WAY
MONDAY AND THE NEXT FRONT WILL ARRIVE BY NEXT TUESDAY.

&&

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

     SMALL CRAFT ADVISORY FOR ROUGH BAR IN EFFECT TIL 5 AM
     SATURDAY FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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





000
FXUS66 KSEW 171615
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
915 AM PDT FRI APR 17 2015

.SYNOPSIS...A WEAK LOW PRESSURE SYSTEM WILL MOVE ACROSS THE AREA
TODAY BUT WILL HAVE LITTLE IMPACT EXCEPT TO STRENGTHEN THE
ONSHORE FLOW. HIGH PRESSURE ALOFT WILL PREVAIL OVER THE REGION
THIS WEEKEND FOR DRY...WARM WEATHER.

&&

.SHORT TERM...
THE TAIL END OF A WEAK COLD FRONT WAS MOVING ACROSS THE CWA AT
THIS TIME. THERE WERE SOME SPRINKLES ASSOCIATED WITH IT. THE FRONT
SHOULD BE EAST OF THE CWA BY MIDDAY. OTHERWISE...THE MAIN IMPACT
OF THE FRONT WILL BE INCREASED ONSHORE FLOW. EXPECT THE UPPER
TROF TO MOVE ACROSS THE AREA THIS AFTERNOON. AN UPPER RIDGE WILL
BUILD OVER THE REGION FROM THE WEST TONIGHT.

AN OFFSHORE UPPER RIDGE WILL BUILD AS IT MOVES INSIDE OF 130W ON
SATURDAY...WITH DRIER NORTHWEST FLOW ALOFT OVER WESTERN
WASHINGTON. ASIDE FROM BRIEF MORNING CLOUDS MAINLY ALONG THE COAST
AND IN THE LOWER CHEHALIS VALLEY...SATURDAY SHOULD BE A MOSTLY
SUNNY DAY. NORTHWEST PRESSURE GRADIENTS WILL KEEP THE LOW LEVEL
FLOW WEAKLY ONSHORE...BUT IT SHOULD BE A LITTLE WARMER WITH HIGHS
MAINLY 60 TO 70.

THE UPPER RIDGE WILL PROGRESS TO THE PACIFIC NORTHWEST COAST ON
SUNDAY. AT MOST...LOW LEVEL FLOW WILL BE VERY WEAK...AND THERE
COULD BE A WEAK THERMALLY INDUCED SURFACE TROUGH OVER WESTERN
WASHINGTON. AT ANY RATE IT WILL BE A SUNNY DAY AND SLIGHTLY
WARMER YET.   MCDONNAL/05

.LONG TERM FROM THE PREV DISCUSSION...
THE UPPER RIDGE WILL WEAKEN AS IT MOVES INLAND ON MONDAY...BUT THE
LOWER REACHES OF THE AIR MASS SHOULD REMAIN AS WARM OR BE A LITTLE
WARMER THAN SUNDAY.

THE RIDGE WILL MOVE EAST OF THE CASCADES ON TUESDAY. THEN AN
OFFSHORE UPPER TROUGH WILL BRING MOIST SOUTHERLY FLOW ALOFT OVER
WESTERN WASHINGTON...WITH INCREASING ONSHORE LOW LEVEL FLOW. THE
MODELS LEAVE LOTS OF UNCERTAINTY WITH REGARD TO WHEN THIS WILL
HAPPEN. THE MOST RECENT RUNS OF THE GFS...EUROPEAN MODEL...AND
CANADIAN MODEL ALL SHOW A FASTER PROGRESSION WITH STRONG ONSHORE
FLOW AND SOME SHOWERS OVER WESTERN WASHINGTON TUESDAY AFTERNOON.
UNTIL WE SEE THAT THIS IS A CLEAR TREND IN THE MODELS...WE WILL STAY
WITH A MOSTLY SUNNY FORECAST FOR TUESDAY. THE UPPER TROUGH SHOULD BE
OVER THE AREA WEDNESDAY AND THURSDAY FOR COOLER WEATHER AND
SCATTERED SHOWERS.   MCDONNAL

&&

.AVIATION...AT 830 AM THERE WAS AN AREA OF LOW CLOUDS AND PATCHY
FOG FROM ABOUT KPAE NORTH THAT WILL BURN OFF LATE THIS MORNING.
THERE IS AN UPPER LEVEL TROUGH MOVING THROUGH B.C. TODAY AND AN
AREA OF MID LEVEL CLOUDS ASSOCIATED WITH THAT WAS OVER SOME OF WRN
WA THIS MORNING...A WEAK DRY COLD FRONT ALOFT. THE FLOW ALOFT IS
WSW AND WILL SWITCH TO NW AND INCREASE LATER THIS AFTERNOON AND
EVENING. SURFACE HIGH PRESSURE AND AN UPPER RIDGE WILL BUILD INTO
THE AREA FOR THE WEEKEND WITH THERMALLY INDUCED LOW PRESSURE OVER
CALIF EXTENDING SOMEWHAT NORTH ALONG THE OREGON COAST. A FEW AREAS
OF MORNING LOW CLOUDS AND FOG ON SATURDAY WILL GIVE WAY TO A SUNNY
DAY.

KSEA...SOME MID LEVEL CLOUDS FOR AWHILE TODAY AS AN UPPER TROUGH
MOVING THROUGH B.C. CLIPS WRN WA. THE NLY BREEZE SHOULD PICK UP THIS
AFTERNOON AND EVENING AS HIGH PRESSURE BUILDS IN. WE MAY SEE A FEW
HOURS OF LOW CLOUDS AND PATCHY FOG AROUND DAYBREAK SATURDAY.

&&

.MARINE...STRONG SURFACE HIGH PRESSURE WILL BUILD JUST OFFSHORE AND
INTO B.C. THROUGH TONIGHT AND SATURDAY. THIS SHOULD GIVE A PRETTY
DECENT NW BREEZE OVER THE COASTAL WATERS AND IN THE STRAIT THIS
AFTERNOON AND EVENING FOR SMALL CRAFT ADVISORY CONDITIONS THERE. A
DEVELOPING NW WIND IN THE STRAIT OF GEORGIA THIS AFTERNOON AND
EVENING MAY DRIVE SOUTH INTO THE SAN JUANS...SO I MAY EXTEND SMALL
CRAFT ADVISORIES TO THE NRN WATERS ON THE AFTERNOON FORECAST
DEPENDING ON WHAT THE WRFGFS AND HRRR SHOW TODAY...BUT AS OF 830 AM
THERE IS NOT YET MUCH WIND IN THE STRAIT OF GEORGIA DESPITE THE
STRONG PRESSURE RISES BETWEEN VRISL AND THE HAIDA GWAII. OVER THE
WEEKEND...THERMALLY INDUCED LOWER PRESSURE WILL DEVELOP OVER CALIF
AND EXTEND ALONG THE SRN OREGON COAST...THAT MAY CONTINUE TO DRIVE
A BRISK NW WIND ALONG THE COAST...ESPECIALLY IN THE AFTERNOON AND
EVENING HOURS. THE UPPER RIDGE WILL GIVE WAY MONDAY AND THE NEXT
FRONT WILL ARRIVE BY NEXT TUESDAY.

&&

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

     SMALL CRAFT ADVISORY FOR ROUGH BAR IN EFFECT TIL 5 AM SATURDAY
     FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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





000
FXUS66 KSEW 171615
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
915 AM PDT FRI APR 17 2015

.SYNOPSIS...A WEAK LOW PRESSURE SYSTEM WILL MOVE ACROSS THE AREA
TODAY BUT WILL HAVE LITTLE IMPACT EXCEPT TO STRENGTHEN THE
ONSHORE FLOW. HIGH PRESSURE ALOFT WILL PREVAIL OVER THE REGION
THIS WEEKEND FOR DRY...WARM WEATHER.

&&

.SHORT TERM...
THE TAIL END OF A WEAK COLD FRONT WAS MOVING ACROSS THE CWA AT
THIS TIME. THERE WERE SOME SPRINKLES ASSOCIATED WITH IT. THE FRONT
SHOULD BE EAST OF THE CWA BY MIDDAY. OTHERWISE...THE MAIN IMPACT
OF THE FRONT WILL BE INCREASED ONSHORE FLOW. EXPECT THE UPPER
TROF TO MOVE ACROSS THE AREA THIS AFTERNOON. AN UPPER RIDGE WILL
BUILD OVER THE REGION FROM THE WEST TONIGHT.

AN OFFSHORE UPPER RIDGE WILL BUILD AS IT MOVES INSIDE OF 130W ON
SATURDAY...WITH DRIER NORTHWEST FLOW ALOFT OVER WESTERN
WASHINGTON. ASIDE FROM BRIEF MORNING CLOUDS MAINLY ALONG THE COAST
AND IN THE LOWER CHEHALIS VALLEY...SATURDAY SHOULD BE A MOSTLY
SUNNY DAY. NORTHWEST PRESSURE GRADIENTS WILL KEEP THE LOW LEVEL
FLOW WEAKLY ONSHORE...BUT IT SHOULD BE A LITTLE WARMER WITH HIGHS
MAINLY 60 TO 70.

THE UPPER RIDGE WILL PROGRESS TO THE PACIFIC NORTHWEST COAST ON
SUNDAY. AT MOST...LOW LEVEL FLOW WILL BE VERY WEAK...AND THERE
COULD BE A WEAK THERMALLY INDUCED SURFACE TROUGH OVER WESTERN
WASHINGTON. AT ANY RATE IT WILL BE A SUNNY DAY AND SLIGHTLY
WARMER YET.   MCDONNAL/05

.LONG TERM FROM THE PREV DISCUSSION...
THE UPPER RIDGE WILL WEAKEN AS IT MOVES INLAND ON MONDAY...BUT THE
LOWER REACHES OF THE AIR MASS SHOULD REMAIN AS WARM OR BE A LITTLE
WARMER THAN SUNDAY.

THE RIDGE WILL MOVE EAST OF THE CASCADES ON TUESDAY. THEN AN
OFFSHORE UPPER TROUGH WILL BRING MOIST SOUTHERLY FLOW ALOFT OVER
WESTERN WASHINGTON...WITH INCREASING ONSHORE LOW LEVEL FLOW. THE
MODELS LEAVE LOTS OF UNCERTAINTY WITH REGARD TO WHEN THIS WILL
HAPPEN. THE MOST RECENT RUNS OF THE GFS...EUROPEAN MODEL...AND
CANADIAN MODEL ALL SHOW A FASTER PROGRESSION WITH STRONG ONSHORE
FLOW AND SOME SHOWERS OVER WESTERN WASHINGTON TUESDAY AFTERNOON.
UNTIL WE SEE THAT THIS IS A CLEAR TREND IN THE MODELS...WE WILL STAY
WITH A MOSTLY SUNNY FORECAST FOR TUESDAY. THE UPPER TROUGH SHOULD BE
OVER THE AREA WEDNESDAY AND THURSDAY FOR COOLER WEATHER AND
SCATTERED SHOWERS.   MCDONNAL

&&

.AVIATION...AT 830 AM THERE WAS AN AREA OF LOW CLOUDS AND PATCHY
FOG FROM ABOUT KPAE NORTH THAT WILL BURN OFF LATE THIS MORNING.
THERE IS AN UPPER LEVEL TROUGH MOVING THROUGH B.C. TODAY AND AN
AREA OF MID LEVEL CLOUDS ASSOCIATED WITH THAT WAS OVER SOME OF WRN
WA THIS MORNING...A WEAK DRY COLD FRONT ALOFT. THE FLOW ALOFT IS
WSW AND WILL SWITCH TO NW AND INCREASE LATER THIS AFTERNOON AND
EVENING. SURFACE HIGH PRESSURE AND AN UPPER RIDGE WILL BUILD INTO
THE AREA FOR THE WEEKEND WITH THERMALLY INDUCED LOW PRESSURE OVER
CALIF EXTENDING SOMEWHAT NORTH ALONG THE OREGON COAST. A FEW AREAS
OF MORNING LOW CLOUDS AND FOG ON SATURDAY WILL GIVE WAY TO A SUNNY
DAY.

KSEA...SOME MID LEVEL CLOUDS FOR AWHILE TODAY AS AN UPPER TROUGH
MOVING THROUGH B.C. CLIPS WRN WA. THE NLY BREEZE SHOULD PICK UP THIS
AFTERNOON AND EVENING AS HIGH PRESSURE BUILDS IN. WE MAY SEE A FEW
HOURS OF LOW CLOUDS AND PATCHY FOG AROUND DAYBREAK SATURDAY.

&&

.MARINE...STRONG SURFACE HIGH PRESSURE WILL BUILD JUST OFFSHORE AND
INTO B.C. THROUGH TONIGHT AND SATURDAY. THIS SHOULD GIVE A PRETTY
DECENT NW BREEZE OVER THE COASTAL WATERS AND IN THE STRAIT THIS
AFTERNOON AND EVENING FOR SMALL CRAFT ADVISORY CONDITIONS THERE. A
DEVELOPING NW WIND IN THE STRAIT OF GEORGIA THIS AFTERNOON AND
EVENING MAY DRIVE SOUTH INTO THE SAN JUANS...SO I MAY EXTEND SMALL
CRAFT ADVISORIES TO THE NRN WATERS ON THE AFTERNOON FORECAST
DEPENDING ON WHAT THE WRFGFS AND HRRR SHOW TODAY...BUT AS OF 830 AM
THERE IS NOT YET MUCH WIND IN THE STRAIT OF GEORGIA DESPITE THE
STRONG PRESSURE RISES BETWEEN VRISL AND THE HAIDA GWAII. OVER THE
WEEKEND...THERMALLY INDUCED LOWER PRESSURE WILL DEVELOP OVER CALIF
AND EXTEND ALONG THE SRN OREGON COAST...THAT MAY CONTINUE TO DRIVE
A BRISK NW WIND ALONG THE COAST...ESPECIALLY IN THE AFTERNOON AND
EVENING HOURS. THE UPPER RIDGE WILL GIVE WAY MONDAY AND THE NEXT
FRONT WILL ARRIVE BY NEXT TUESDAY.

&&

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

     SMALL CRAFT ADVISORY FOR ROUGH BAR IN EFFECT TIL 5 AM SATURDAY
     FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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






000
FXUS66 KSEW 171615
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
915 AM PDT FRI APR 17 2015

.SYNOPSIS...A WEAK LOW PRESSURE SYSTEM WILL MOVE ACROSS THE AREA
TODAY BUT WILL HAVE LITTLE IMPACT EXCEPT TO STRENGTHEN THE
ONSHORE FLOW. HIGH PRESSURE ALOFT WILL PREVAIL OVER THE REGION
THIS WEEKEND FOR DRY...WARM WEATHER.

&&

.SHORT TERM...
THE TAIL END OF A WEAK COLD FRONT WAS MOVING ACROSS THE CWA AT
THIS TIME. THERE WERE SOME SPRINKLES ASSOCIATED WITH IT. THE FRONT
SHOULD BE EAST OF THE CWA BY MIDDAY. OTHERWISE...THE MAIN IMPACT
OF THE FRONT WILL BE INCREASED ONSHORE FLOW. EXPECT THE UPPER
TROF TO MOVE ACROSS THE AREA THIS AFTERNOON. AN UPPER RIDGE WILL
BUILD OVER THE REGION FROM THE WEST TONIGHT.

AN OFFSHORE UPPER RIDGE WILL BUILD AS IT MOVES INSIDE OF 130W ON
SATURDAY...WITH DRIER NORTHWEST FLOW ALOFT OVER WESTERN
WASHINGTON. ASIDE FROM BRIEF MORNING CLOUDS MAINLY ALONG THE COAST
AND IN THE LOWER CHEHALIS VALLEY...SATURDAY SHOULD BE A MOSTLY
SUNNY DAY. NORTHWEST PRESSURE GRADIENTS WILL KEEP THE LOW LEVEL
FLOW WEAKLY ONSHORE...BUT IT SHOULD BE A LITTLE WARMER WITH HIGHS
MAINLY 60 TO 70.

THE UPPER RIDGE WILL PROGRESS TO THE PACIFIC NORTHWEST COAST ON
SUNDAY. AT MOST...LOW LEVEL FLOW WILL BE VERY WEAK...AND THERE
COULD BE A WEAK THERMALLY INDUCED SURFACE TROUGH OVER WESTERN
WASHINGTON. AT ANY RATE IT WILL BE A SUNNY DAY AND SLIGHTLY
WARMER YET.   MCDONNAL/05

.LONG TERM FROM THE PREV DISCUSSION...
THE UPPER RIDGE WILL WEAKEN AS IT MOVES INLAND ON MONDAY...BUT THE
LOWER REACHES OF THE AIR MASS SHOULD REMAIN AS WARM OR BE A LITTLE
WARMER THAN SUNDAY.

THE RIDGE WILL MOVE EAST OF THE CASCADES ON TUESDAY. THEN AN
OFFSHORE UPPER TROUGH WILL BRING MOIST SOUTHERLY FLOW ALOFT OVER
WESTERN WASHINGTON...WITH INCREASING ONSHORE LOW LEVEL FLOW. THE
MODELS LEAVE LOTS OF UNCERTAINTY WITH REGARD TO WHEN THIS WILL
HAPPEN. THE MOST RECENT RUNS OF THE GFS...EUROPEAN MODEL...AND
CANADIAN MODEL ALL SHOW A FASTER PROGRESSION WITH STRONG ONSHORE
FLOW AND SOME SHOWERS OVER WESTERN WASHINGTON TUESDAY AFTERNOON.
UNTIL WE SEE THAT THIS IS A CLEAR TREND IN THE MODELS...WE WILL STAY
WITH A MOSTLY SUNNY FORECAST FOR TUESDAY. THE UPPER TROUGH SHOULD BE
OVER THE AREA WEDNESDAY AND THURSDAY FOR COOLER WEATHER AND
SCATTERED SHOWERS.   MCDONNAL

&&

.AVIATION...AT 830 AM THERE WAS AN AREA OF LOW CLOUDS AND PATCHY
FOG FROM ABOUT KPAE NORTH THAT WILL BURN OFF LATE THIS MORNING.
THERE IS AN UPPER LEVEL TROUGH MOVING THROUGH B.C. TODAY AND AN
AREA OF MID LEVEL CLOUDS ASSOCIATED WITH THAT WAS OVER SOME OF WRN
WA THIS MORNING...A WEAK DRY COLD FRONT ALOFT. THE FLOW ALOFT IS
WSW AND WILL SWITCH TO NW AND INCREASE LATER THIS AFTERNOON AND
EVENING. SURFACE HIGH PRESSURE AND AN UPPER RIDGE WILL BUILD INTO
THE AREA FOR THE WEEKEND WITH THERMALLY INDUCED LOW PRESSURE OVER
CALIF EXTENDING SOMEWHAT NORTH ALONG THE OREGON COAST. A FEW AREAS
OF MORNING LOW CLOUDS AND FOG ON SATURDAY WILL GIVE WAY TO A SUNNY
DAY.

KSEA...SOME MID LEVEL CLOUDS FOR AWHILE TODAY AS AN UPPER TROUGH
MOVING THROUGH B.C. CLIPS WRN WA. THE NLY BREEZE SHOULD PICK UP THIS
AFTERNOON AND EVENING AS HIGH PRESSURE BUILDS IN. WE MAY SEE A FEW
HOURS OF LOW CLOUDS AND PATCHY FOG AROUND DAYBREAK SATURDAY.

&&

.MARINE...STRONG SURFACE HIGH PRESSURE WILL BUILD JUST OFFSHORE AND
INTO B.C. THROUGH TONIGHT AND SATURDAY. THIS SHOULD GIVE A PRETTY
DECENT NW BREEZE OVER THE COASTAL WATERS AND IN THE STRAIT THIS
AFTERNOON AND EVENING FOR SMALL CRAFT ADVISORY CONDITIONS THERE. A
DEVELOPING NW WIND IN THE STRAIT OF GEORGIA THIS AFTERNOON AND
EVENING MAY DRIVE SOUTH INTO THE SAN JUANS...SO I MAY EXTEND SMALL
CRAFT ADVISORIES TO THE NRN WATERS ON THE AFTERNOON FORECAST
DEPENDING ON WHAT THE WRFGFS AND HRRR SHOW TODAY...BUT AS OF 830 AM
THERE IS NOT YET MUCH WIND IN THE STRAIT OF GEORGIA DESPITE THE
STRONG PRESSURE RISES BETWEEN VRISL AND THE HAIDA GWAII. OVER THE
WEEKEND...THERMALLY INDUCED LOWER PRESSURE WILL DEVELOP OVER CALIF
AND EXTEND ALONG THE SRN OREGON COAST...THAT MAY CONTINUE TO DRIVE
A BRISK NW WIND ALONG THE COAST...ESPECIALLY IN THE AFTERNOON AND
EVENING HOURS. THE UPPER RIDGE WILL GIVE WAY MONDAY AND THE NEXT
FRONT WILL ARRIVE BY NEXT TUESDAY.

&&

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

     SMALL CRAFT ADVISORY FOR ROUGH BAR IN EFFECT TIL 5 AM SATURDAY
     FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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





000
FXUS66 KSEW 171615
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
915 AM PDT FRI APR 17 2015

.SYNOPSIS...A WEAK LOW PRESSURE SYSTEM WILL MOVE ACROSS THE AREA
TODAY BUT WILL HAVE LITTLE IMPACT EXCEPT TO STRENGTHEN THE
ONSHORE FLOW. HIGH PRESSURE ALOFT WILL PREVAIL OVER THE REGION
THIS WEEKEND FOR DRY...WARM WEATHER.

&&

.SHORT TERM...
THE TAIL END OF A WEAK COLD FRONT WAS MOVING ACROSS THE CWA AT
THIS TIME. THERE WERE SOME SPRINKLES ASSOCIATED WITH IT. THE FRONT
SHOULD BE EAST OF THE CWA BY MIDDAY. OTHERWISE...THE MAIN IMPACT
OF THE FRONT WILL BE INCREASED ONSHORE FLOW. EXPECT THE UPPER
TROF TO MOVE ACROSS THE AREA THIS AFTERNOON. AN UPPER RIDGE WILL
BUILD OVER THE REGION FROM THE WEST TONIGHT.

AN OFFSHORE UPPER RIDGE WILL BUILD AS IT MOVES INSIDE OF 130W ON
SATURDAY...WITH DRIER NORTHWEST FLOW ALOFT OVER WESTERN
WASHINGTON. ASIDE FROM BRIEF MORNING CLOUDS MAINLY ALONG THE COAST
AND IN THE LOWER CHEHALIS VALLEY...SATURDAY SHOULD BE A MOSTLY
SUNNY DAY. NORTHWEST PRESSURE GRADIENTS WILL KEEP THE LOW LEVEL
FLOW WEAKLY ONSHORE...BUT IT SHOULD BE A LITTLE WARMER WITH HIGHS
MAINLY 60 TO 70.

THE UPPER RIDGE WILL PROGRESS TO THE PACIFIC NORTHWEST COAST ON
SUNDAY. AT MOST...LOW LEVEL FLOW WILL BE VERY WEAK...AND THERE
COULD BE A WEAK THERMALLY INDUCED SURFACE TROUGH OVER WESTERN
WASHINGTON. AT ANY RATE IT WILL BE A SUNNY DAY AND SLIGHTLY
WARMER YET.   MCDONNAL/05

.LONG TERM FROM THE PREV DISCUSSION...
THE UPPER RIDGE WILL WEAKEN AS IT MOVES INLAND ON MONDAY...BUT THE
LOWER REACHES OF THE AIR MASS SHOULD REMAIN AS WARM OR BE A LITTLE
WARMER THAN SUNDAY.

THE RIDGE WILL MOVE EAST OF THE CASCADES ON TUESDAY. THEN AN
OFFSHORE UPPER TROUGH WILL BRING MOIST SOUTHERLY FLOW ALOFT OVER
WESTERN WASHINGTON...WITH INCREASING ONSHORE LOW LEVEL FLOW. THE
MODELS LEAVE LOTS OF UNCERTAINTY WITH REGARD TO WHEN THIS WILL
HAPPEN. THE MOST RECENT RUNS OF THE GFS...EUROPEAN MODEL...AND
CANADIAN MODEL ALL SHOW A FASTER PROGRESSION WITH STRONG ONSHORE
FLOW AND SOME SHOWERS OVER WESTERN WASHINGTON TUESDAY AFTERNOON.
UNTIL WE SEE THAT THIS IS A CLEAR TREND IN THE MODELS...WE WILL STAY
WITH A MOSTLY SUNNY FORECAST FOR TUESDAY. THE UPPER TROUGH SHOULD BE
OVER THE AREA WEDNESDAY AND THURSDAY FOR COOLER WEATHER AND
SCATTERED SHOWERS.   MCDONNAL

&&

.AVIATION...AT 830 AM THERE WAS AN AREA OF LOW CLOUDS AND PATCHY
FOG FROM ABOUT KPAE NORTH THAT WILL BURN OFF LATE THIS MORNING.
THERE IS AN UPPER LEVEL TROUGH MOVING THROUGH B.C. TODAY AND AN
AREA OF MID LEVEL CLOUDS ASSOCIATED WITH THAT WAS OVER SOME OF WRN
WA THIS MORNING...A WEAK DRY COLD FRONT ALOFT. THE FLOW ALOFT IS
WSW AND WILL SWITCH TO NW AND INCREASE LATER THIS AFTERNOON AND
EVENING. SURFACE HIGH PRESSURE AND AN UPPER RIDGE WILL BUILD INTO
THE AREA FOR THE WEEKEND WITH THERMALLY INDUCED LOW PRESSURE OVER
CALIF EXTENDING SOMEWHAT NORTH ALONG THE OREGON COAST. A FEW AREAS
OF MORNING LOW CLOUDS AND FOG ON SATURDAY WILL GIVE WAY TO A SUNNY
DAY.

KSEA...SOME MID LEVEL CLOUDS FOR AWHILE TODAY AS AN UPPER TROUGH
MOVING THROUGH B.C. CLIPS WRN WA. THE NLY BREEZE SHOULD PICK UP THIS
AFTERNOON AND EVENING AS HIGH PRESSURE BUILDS IN. WE MAY SEE A FEW
HOURS OF LOW CLOUDS AND PATCHY FOG AROUND DAYBREAK SATURDAY.

&&

.MARINE...STRONG SURFACE HIGH PRESSURE WILL BUILD JUST OFFSHORE AND
INTO B.C. THROUGH TONIGHT AND SATURDAY. THIS SHOULD GIVE A PRETTY
DECENT NW BREEZE OVER THE COASTAL WATERS AND IN THE STRAIT THIS
AFTERNOON AND EVENING FOR SMALL CRAFT ADVISORY CONDITIONS THERE. A
DEVELOPING NW WIND IN THE STRAIT OF GEORGIA THIS AFTERNOON AND
EVENING MAY DRIVE SOUTH INTO THE SAN JUANS...SO I MAY EXTEND SMALL
CRAFT ADVISORIES TO THE NRN WATERS ON THE AFTERNOON FORECAST
DEPENDING ON WHAT THE WRFGFS AND HRRR SHOW TODAY...BUT AS OF 830 AM
THERE IS NOT YET MUCH WIND IN THE STRAIT OF GEORGIA DESPITE THE
STRONG PRESSURE RISES BETWEEN VRISL AND THE HAIDA GWAII. OVER THE
WEEKEND...THERMALLY INDUCED LOWER PRESSURE WILL DEVELOP OVER CALIF
AND EXTEND ALONG THE SRN OREGON COAST...THAT MAY CONTINUE TO DRIVE
A BRISK NW WIND ALONG THE COAST...ESPECIALLY IN THE AFTERNOON AND
EVENING HOURS. THE UPPER RIDGE WILL GIVE WAY MONDAY AND THE NEXT
FRONT WILL ARRIVE BY NEXT TUESDAY.

&&

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

     SMALL CRAFT ADVISORY FOR ROUGH BAR IN EFFECT TIL 5 AM SATURDAY
     FOR THE GRAYS HARBOR BAR.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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






000
FXUS66 KSEW 170954
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 AM PDT FRI APR 17 2015

.SYNOPSIS...A WEAK UPPER TROUGH WILL BRUSH WESTERN WASHINGTON TODAY
AS IT MOVES THROUGH BRITISH COLUMBIA. IT WILL BRING SOME CLOUDS...
BUT THE AREA SHOULD STILL HAVE A MOSTLY TO PARTLY SUNNY DAY. A
STRONG UPPER RIDGE WILL MOVE ACROSS THE REGION THIS WEEKEND AND
EARLY NEXT WEEK FOR SUNNY WARM WEATHER. AN UPPER TROUGH WILL REACH
THE AREA BY WEDNESDAY FOR COOLER SHOWERY WEATHER.

&&

.SHORT TERM...THE UPPER LEVEL RIDGE OVER THE PACIFIC NORTHWEST IS
WEAKENING AS IT MOVES EAST OF THE CASCADES EARLY THIS MORNING...AND
A WEAK UPPER LEVEL TROUGH OFFSHORE IS MOVING INTO BRITISH COLUMBIA.
SKIES ARE MAINLY CLEAR...EXCEPT FOR THE CLOUD COVER ASSOCIATED WITH
THE UPPER TROUGH OVER THE NORTHWEST CORNER OF THE OLYMPIC PENINSULA.
TEMPERATURES AT 2 AM WERE IN THE UPPER 30S AND 40S.

THE SOUTH END OF THE UPPER TROUGH WILL MOVE INTO WESTERN WASHINGTON
TODAY AND EAST OF THE CASCADES TONIGHT. ITS PRECIPITATION SHOULD
REMAIN NORTH OF OUR FORECAST AREA. THERE WILL BE SOME MID LEVEL
MOISTURE...AND THE TROUGH WILL TURN THE LOW LEVEL FLOW MORE STRONGLY
ONSHORE. STILL WE CAN EXPECT A MOSTLY SUNNY DAY FOR THE WESTERN
WASHINGTON INTERIOR LOWLANDS AND A PARTLY TO MOSTLY SUNNY DAY FOR
THE COAST AND MOUNTAINS. HIGHS WILL BE IN THE UPPER 50S TO 60S...
SIMILAR TO THURSDAY.

AN OFFSHORE UPPER RIDGE WILL BUILD AS IT MOVES INSIDE OF 130W ON
SATURDAY...WITH DRIER NORTHWEST FLOW ALOFT OVER WESTERN WASHINGTON.
ASIDE FROM BRIEF MORNING CLOUDS MAINLY ALONG THE COAST AND IN THE
LOWER CHEHALIS VALLEY...SATURDAY SHOULD BE A MOSTLY SUNNY DAY.
NORTHWEST PRESSURE GRADIENTS WILL KEEP THE LOW LEVEL FLOW WEAKLY
ONSHORE...BUT IT SHOULD BE A LITTLE WARMER WITH HIGHS MAINLY 60 TO
70.

THE UPPER RIDGE WILL PROGRESS TO THE PACIFIC NORTHWEST COAST ON
SUNDAY. AT MOST...LOW LEVEL FLOW WILL BE VERY WEAK...AND THERE COULD
BE A WEAK THERMALLY INDUCED SURFACE TROUGH OVER WESTERN WASHINGTON.
AT ANY RATE IT WILL BE A SUNNY DAY AND SLIGHTLY WARMER YET.
MCDONNAL

.LONG TERM...THE UPPER RIDGE WILL WEAKEN AS IT MOVES INLAND ON
MONDAY...BUT THE LOWER REACHES OF THE AIR MASS SHOULD REMAIN AS WARM
OR BE A LITTLE WARMER THAN SUNDAY.

THE RIDGE WILL MOVE EAST OF THE CASCADES ON TUESDAY. THEN AN
OFFSHORE UPPER TROUGH WILL BRING MOIST SOUTHERLY FLOW ALOFT OVER
WESTERN WASHINGTON...WITH INCREASING ONSHORE LOW LEVEL FLOW. THE
MODELS LEAVE LOTS OF UNCERTAINTY WITH REGARD TO WHEN THIS WILL
HAPPEN. THE MOST RECENT RUNS OF THE GFS...EUROPEAN MODEL...AND
CANADIAN MODEL ALL SHOW A FASTER PROGRESSION WITH STRONG ONSHORE
FLOW AND SOME SHOWERS OVER WESTERN WASHINGTON TUESDAY AFTERNOON.
UNTIL WE SEE THAT THIS IS A CLEAR TREND IN THE MODELS...WE WILL STAY
WITH A MOSTLY SUNNY FORECAST FOR TUESDAY. THE UPPER TROUGH SHOULD BE
OVER THE AREA WEDNESDAY AND THURSDAY FOR COOLER WEATHER AND
SCATTERED SHOWERS.   MCDONNAL

&&

.AVIATION...A WEAK UPPER LEVEL TROUGH AND SURFACE COLD FRONT WILL
CROSS WESTERN WA TODAY. HOWEVER THERE IS LITTLE MOISTURE ATTACHED
WITH THIS SYSTEM AND DRY WEATHER IS EXPECTED. THE FLOW ALOFT IS
WESTERLY. VFR CONDITIONS EXPECTED. HIGH PRESSURE WILL BUILD OVER THE
AREA TONIGHT FOR DRY AND STABLE WEATHER. 33

KSEA...FEW-SCT MID OR HIGH CLOUDS TODAY WITH N WINDS TO 10 KT. 33

&&

.MARINE...ONSHORE FLOW WILL INCREASE TODAY AS A COLD FRONT CROSSES
WESTERN WA. THE COASTAL WATERS WILL LIKELY SEE SMALL CRAFT ADVISORY
WINDS THIS EVENING...WITH GALES POSSIBLE THROUGH THE CENTRAL AND
EAST STRAIT. MEANWHILE...WEST SWELL 10-12 FT WILL SUBSIDE TO 9 FT BY
MID MORNING.

LOW PRESSURE WILL FORM ALONG THE COAST THIS WEEKEND FOR NORTHERLY
FLOW. OFFSHORE FLOW WILL CONTINUE ON MONDAY. THE NEXT FRONT WILL
ARRIVE NEXT TUESDAY. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COAST AND WEST ENTRANCE FOR HAZARDOUS SEAS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.
     SMALL CRAFT ADVISORY CENTRAL AND EAST STRAIT TODAY.
     GALE WATCH THIS EVENING CENTRAL AND EAST STRAIT.

&&

$$

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






000
FXUS66 KSEW 170954
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 AM PDT FRI APR 17 2015

.SYNOPSIS...A WEAK UPPER TROUGH WILL BRUSH WESTERN WASHINGTON TODAY
AS IT MOVES THROUGH BRITISH COLUMBIA. IT WILL BRING SOME CLOUDS...
BUT THE AREA SHOULD STILL HAVE A MOSTLY TO PARTLY SUNNY DAY. A
STRONG UPPER RIDGE WILL MOVE ACROSS THE REGION THIS WEEKEND AND
EARLY NEXT WEEK FOR SUNNY WARM WEATHER. AN UPPER TROUGH WILL REACH
THE AREA BY WEDNESDAY FOR COOLER SHOWERY WEATHER.

&&

.SHORT TERM...THE UPPER LEVEL RIDGE OVER THE PACIFIC NORTHWEST IS
WEAKENING AS IT MOVES EAST OF THE CASCADES EARLY THIS MORNING...AND
A WEAK UPPER LEVEL TROUGH OFFSHORE IS MOVING INTO BRITISH COLUMBIA.
SKIES ARE MAINLY CLEAR...EXCEPT FOR THE CLOUD COVER ASSOCIATED WITH
THE UPPER TROUGH OVER THE NORTHWEST CORNER OF THE OLYMPIC PENINSULA.
TEMPERATURES AT 2 AM WERE IN THE UPPER 30S AND 40S.

THE SOUTH END OF THE UPPER TROUGH WILL MOVE INTO WESTERN WASHINGTON
TODAY AND EAST OF THE CASCADES TONIGHT. ITS PRECIPITATION SHOULD
REMAIN NORTH OF OUR FORECAST AREA. THERE WILL BE SOME MID LEVEL
MOISTURE...AND THE TROUGH WILL TURN THE LOW LEVEL FLOW MORE STRONGLY
ONSHORE. STILL WE CAN EXPECT A MOSTLY SUNNY DAY FOR THE WESTERN
WASHINGTON INTERIOR LOWLANDS AND A PARTLY TO MOSTLY SUNNY DAY FOR
THE COAST AND MOUNTAINS. HIGHS WILL BE IN THE UPPER 50S TO 60S...
SIMILAR TO THURSDAY.

AN OFFSHORE UPPER RIDGE WILL BUILD AS IT MOVES INSIDE OF 130W ON
SATURDAY...WITH DRIER NORTHWEST FLOW ALOFT OVER WESTERN WASHINGTON.
ASIDE FROM BRIEF MORNING CLOUDS MAINLY ALONG THE COAST AND IN THE
LOWER CHEHALIS VALLEY...SATURDAY SHOULD BE A MOSTLY SUNNY DAY.
NORTHWEST PRESSURE GRADIENTS WILL KEEP THE LOW LEVEL FLOW WEAKLY
ONSHORE...BUT IT SHOULD BE A LITTLE WARMER WITH HIGHS MAINLY 60 TO
70.

THE UPPER RIDGE WILL PROGRESS TO THE PACIFIC NORTHWEST COAST ON
SUNDAY. AT MOST...LOW LEVEL FLOW WILL BE VERY WEAK...AND THERE COULD
BE A WEAK THERMALLY INDUCED SURFACE TROUGH OVER WESTERN WASHINGTON.
AT ANY RATE IT WILL BE A SUNNY DAY AND SLIGHTLY WARMER YET.
MCDONNAL

.LONG TERM...THE UPPER RIDGE WILL WEAKEN AS IT MOVES INLAND ON
MONDAY...BUT THE LOWER REACHES OF THE AIR MASS SHOULD REMAIN AS WARM
OR BE A LITTLE WARMER THAN SUNDAY.

THE RIDGE WILL MOVE EAST OF THE CASCADES ON TUESDAY. THEN AN
OFFSHORE UPPER TROUGH WILL BRING MOIST SOUTHERLY FLOW ALOFT OVER
WESTERN WASHINGTON...WITH INCREASING ONSHORE LOW LEVEL FLOW. THE
MODELS LEAVE LOTS OF UNCERTAINTY WITH REGARD TO WHEN THIS WILL
HAPPEN. THE MOST RECENT RUNS OF THE GFS...EUROPEAN MODEL...AND
CANADIAN MODEL ALL SHOW A FASTER PROGRESSION WITH STRONG ONSHORE
FLOW AND SOME SHOWERS OVER WESTERN WASHINGTON TUESDAY AFTERNOON.
UNTIL WE SEE THAT THIS IS A CLEAR TREND IN THE MODELS...WE WILL STAY
WITH A MOSTLY SUNNY FORECAST FOR TUESDAY. THE UPPER TROUGH SHOULD BE
OVER THE AREA WEDNESDAY AND THURSDAY FOR COOLER WEATHER AND
SCATTERED SHOWERS.   MCDONNAL

&&

.AVIATION...A WEAK UPPER LEVEL TROUGH AND SURFACE COLD FRONT WILL
CROSS WESTERN WA TODAY. HOWEVER THERE IS LITTLE MOISTURE ATTACHED
WITH THIS SYSTEM AND DRY WEATHER IS EXPECTED. THE FLOW ALOFT IS
WESTERLY. VFR CONDITIONS EXPECTED. HIGH PRESSURE WILL BUILD OVER THE
AREA TONIGHT FOR DRY AND STABLE WEATHER. 33

KSEA...FEW-SCT MID OR HIGH CLOUDS TODAY WITH N WINDS TO 10 KT. 33

&&

.MARINE...ONSHORE FLOW WILL INCREASE TODAY AS A COLD FRONT CROSSES
WESTERN WA. THE COASTAL WATERS WILL LIKELY SEE SMALL CRAFT ADVISORY
WINDS THIS EVENING...WITH GALES POSSIBLE THROUGH THE CENTRAL AND
EAST STRAIT. MEANWHILE...WEST SWELL 10-12 FT WILL SUBSIDE TO 9 FT BY
MID MORNING.

LOW PRESSURE WILL FORM ALONG THE COAST THIS WEEKEND FOR NORTHERLY
FLOW. OFFSHORE FLOW WILL CONTINUE ON MONDAY. THE NEXT FRONT WILL
ARRIVE NEXT TUESDAY. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COAST AND WEST ENTRANCE FOR HAZARDOUS SEAS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.
     SMALL CRAFT ADVISORY CENTRAL AND EAST STRAIT TODAY.
     GALE WATCH THIS EVENING CENTRAL AND EAST STRAIT.

&&

$$

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







000
FXUS66 KSEW 170500
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
955 PM PDT THU APR 16 2015

.SYNOPSIS...AN UPPER LEVEL RIDGE WILL KEEP SKIES MOSTLY CLEAR
TONIGHT WITH COOL TEMPERATURES. A WEAK DRY UPPER LEVEL TROUGH WILL
BRING PERIODS OF CLOUDS TO WESTERN WASHINGTON ON FRIDAY. A STRONGER
UPPER LEVEL RIDGE WILL BRING MOSTLY SUNNY AND WARMER WEATHER
SATURDAY THROUGH TUESDAY. A LARGE UPPER LEVEL TROUGH WILL BRING
SHOWERS TO THE AREA TUESDAY NIGHT THROUGH THURSDAY.

&&

.SHORT TERM...SATELLITE IMAGERY SHOWS UPPER LEVEL RIDGE AXIS HAS
MOVED EAST OF THE AREA TONIGHT. UPPER LEVEL TROUGH OFFSHORE AROUND
133W AT 04Z SLOWLY MOVING EASTWARD. WITH THE TROUGH WELL OFFSHORE
SKIES ARE CLEAR OVER WESTERN WASHINGTON THIS EVENING. TEMPERATURES
AT 04Z RANGED FROM THE MID 40S TO THE MID 50S.

UPPER LEVEL TROUGH CONTINUING TO MOVE EAST TONIGHT BUT WILL STILL BE
FAR ENOUGH OFFSHORE BY FRIDAY MORNING TO KEEP SKIES MOSTLY CLEAR
OVERNIGHT. LOWS WILL BE MOSTLY IN THE 40S.

WHAT IS LEFT OF THE UPPER LEVEL TROUGH MOVING THROUGH WESTERN
WASHINGTON ON FRIDAY. MODEL CROSS SECTIONS SHOW ONLY SOME MID LEVEL
CLOUDS ASSOCIATED WITH THE TROUGH AS IT MOVES ACROSS THE AREA. WILL
STAY WITH THE DRY FORECAST FOR FRIDAY. FLOW ALOFT TURNING
NORTHWESTERLY BEHIND THE FRONT. WITH THE AIR MASS SLIGHTLY UNSTABLE
SOME SC COULD FORM LATE IN AFTERNOON INTO THE EVENING HOURS. EVEN
WITH THE COMBINATION OF THE MID LEVEL CLOUDS AND THE SC LATE IN THE
DAY MOSTLY SUNNY WORDING FOR FRIDAY LOOKS GOOD. HIGHS WILL MOSTLY BE
IN THE LOWER TO MID 60S.

UPPER LEVEL RIDGE BUILDING QUICKLY OFFSHORE FRIDAY NIGHT WITH THE
SURFACE GRADIENTS GOING NORTHWESTERLY. GFS HAS KOLM-KBLI GRADIENT
APPROACHING -2 MB. MODEL CROSS SECTIONS SHOW A VERY SHALLOW LAYER OF
MOISTURE OVER THE INTERIOR SATURDAY MORNING BUT WITH THE INCREASING
NORTHERLY GRADIENTS AND THE WINDS RIGHT OFF THE GROUND NORTHERLY AT
15 KNOTS WILL STAY WITH THE IDEA OF THE MORNING LOW CLOUDS MAINLY
CONFINED TO THE COAST. WITH PLENTY OF SUNSHINE IN THE AFTERNOON
HIGHS IN THE 60S WILL BE COMMON.

DRY AND WARM WEATHER CONTINUING ON SUNDAY AS THE UPPER RIDGE
OFFSHORE BUILDS INLAND. 850 MB TEMPERATURES WARMING TO AROUND PLUS
10C. WITH THE WARMING ALOFT THE WARMER LOCATIONS ON SUNDAY SHOULD
GET INTO THE THE LOWER 70S. FORECAST ON TRACK TONIGHT. FELTON

.LONG TERM...PREVIOUS DISCUSSION FOLLOWS. THE UPPER LEVEL RIDGE AXIS
WILL MOVE OVER THE COAST SUNDAY NIGHT...THEN SHIFT SLOWLY E OVER E
WA ON TUESDAY. WEAK LOW LEVEL OFFSHORE FLOW WILL PUT MAX TEMPS IN
THE 60S TO MID 70S MONDAY AND TUESDAY.

THE GFS...ECMWF...AND CANADIAN CONTINUE TO BE A BIT OF AN
INCONSISTENT MESS FROM TUESDAY NIGHT ONWARD. THERE IS BROAD
AGREEMENT THAT THE UPPER LEVEL RIDGE WILL DRIFT E AND A LARGE UPPER
LEVEL TROUGH WILL APPROACH THE COAST. MOIST S FLOW WILL DEVELOP OVER
W WA AHEAD OF THE TROUGH FOR SOME SHOWERS...BUT JUST WHEN THIS WILL
WILL OCCUR AND HOW IT WILL UNFOLD IS STILL IN DOUBT. SO FOR
NOW...THE TUESDAY NIGHT THROUGH THURSDAY PERIOD HAS A BROADBRUSH
CHANCE OF SHOWERS. KAM

&&

.AVIATION...HIGH PRESSURE OVER THE PAC NW WILL LEAD TO DRY AND
STABLE WEATHER ACROSS WESTERN WA TONIGHT. THE FLOW ALOFT IS
WESTERLY. VFR CONDITIONS WILL CONTINUE. A WEAK COLD FRONT WILL CROSS
THE AREA ON FRIDAY BUT THERE IS LITTLE MOISTURE ATTACHED WITH THIS
SYSTEM. EXPECT VFR CONDITIONS. 33

KSEA...FEW HIGH CLOUDS TONIGHT WITH LIGHT N/NE WINDS. 33

&&

.MARINE...HIGH PRESSURE WILL REMAIN OVER THE AREA TONIGHT. WEST
SWELLS ARE 10 TO 13 FT AND A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS
REMAINS IN EFFECT FOR THE COASTAL WATERS AND WESTERN STRAIT OF JUAN
DE FUCA. MEANWHILE...NORTH WINDS AT DESTRUCTION ARE STILL OVER 20 KT
BUT WINDS SHOULD EASE AFTER MIDNIGHT TONIGHT.

ONSHORE FLOW WILL INCREASE ON FRIDAY AS A COLD FRONT CROSSES WESTERN
WA. THE COASTAL WATERS WILL LIKELY SEE SMALL CRAFT ADVISORY
WINDS...WITH GALES POSSIBLE THROUGH THE CENTRAL AND EAST STRAIT.

LOW PRESSURE WILL FORM ALONG THE COAST THIS WEEKEND FOR NORTHERLY
FLOW. OFFSHORE FLOW WILL CONTINUE ON MONDAY. THE NEXT FRONT WILL
ARRIVE NEXT TUESDAY. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COAST AND WEST ENTRANCE FOR HAZARDOUS SEAS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.
     GALE WATCH FRIDAY EVENING CENTRAL AND EAST STRAIT.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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
















000
FXUS66 KSEW 170500
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
955 PM PDT THU APR 16 2015

.SYNOPSIS...AN UPPER LEVEL RIDGE WILL KEEP SKIES MOSTLY CLEAR
TONIGHT WITH COOL TEMPERATURES. A WEAK DRY UPPER LEVEL TROUGH WILL
BRING PERIODS OF CLOUDS TO WESTERN WASHINGTON ON FRIDAY. A STRONGER
UPPER LEVEL RIDGE WILL BRING MOSTLY SUNNY AND WARMER WEATHER
SATURDAY THROUGH TUESDAY. A LARGE UPPER LEVEL TROUGH WILL BRING
SHOWERS TO THE AREA TUESDAY NIGHT THROUGH THURSDAY.

&&

.SHORT TERM...SATELLITE IMAGERY SHOWS UPPER LEVEL RIDGE AXIS HAS
MOVED EAST OF THE AREA TONIGHT. UPPER LEVEL TROUGH OFFSHORE AROUND
133W AT 04Z SLOWLY MOVING EASTWARD. WITH THE TROUGH WELL OFFSHORE
SKIES ARE CLEAR OVER WESTERN WASHINGTON THIS EVENING. TEMPERATURES
AT 04Z RANGED FROM THE MID 40S TO THE MID 50S.

UPPER LEVEL TROUGH CONTINUING TO MOVE EAST TONIGHT BUT WILL STILL BE
FAR ENOUGH OFFSHORE BY FRIDAY MORNING TO KEEP SKIES MOSTLY CLEAR
OVERNIGHT. LOWS WILL BE MOSTLY IN THE 40S.

WHAT IS LEFT OF THE UPPER LEVEL TROUGH MOVING THROUGH WESTERN
WASHINGTON ON FRIDAY. MODEL CROSS SECTIONS SHOW ONLY SOME MID LEVEL
CLOUDS ASSOCIATED WITH THE TROUGH AS IT MOVES ACROSS THE AREA. WILL
STAY WITH THE DRY FORECAST FOR FRIDAY. FLOW ALOFT TURNING
NORTHWESTERLY BEHIND THE FRONT. WITH THE AIR MASS SLIGHTLY UNSTABLE
SOME SC COULD FORM LATE IN AFTERNOON INTO THE EVENING HOURS. EVEN
WITH THE COMBINATION OF THE MID LEVEL CLOUDS AND THE SC LATE IN THE
DAY MOSTLY SUNNY WORDING FOR FRIDAY LOOKS GOOD. HIGHS WILL MOSTLY BE
IN THE LOWER TO MID 60S.

UPPER LEVEL RIDGE BUILDING QUICKLY OFFSHORE FRIDAY NIGHT WITH THE
SURFACE GRADIENTS GOING NORTHWESTERLY. GFS HAS KOLM-KBLI GRADIENT
APPROACHING -2 MB. MODEL CROSS SECTIONS SHOW A VERY SHALLOW LAYER OF
MOISTURE OVER THE INTERIOR SATURDAY MORNING BUT WITH THE INCREASING
NORTHERLY GRADIENTS AND THE WINDS RIGHT OFF THE GROUND NORTHERLY AT
15 KNOTS WILL STAY WITH THE IDEA OF THE MORNING LOW CLOUDS MAINLY
CONFINED TO THE COAST. WITH PLENTY OF SUNSHINE IN THE AFTERNOON
HIGHS IN THE 60S WILL BE COMMON.

DRY AND WARM WEATHER CONTINUING ON SUNDAY AS THE UPPER RIDGE
OFFSHORE BUILDS INLAND. 850 MB TEMPERATURES WARMING TO AROUND PLUS
10C. WITH THE WARMING ALOFT THE WARMER LOCATIONS ON SUNDAY SHOULD
GET INTO THE THE LOWER 70S. FORECAST ON TRACK TONIGHT. FELTON

.LONG TERM...PREVIOUS DISCUSSION FOLLOWS. THE UPPER LEVEL RIDGE AXIS
WILL MOVE OVER THE COAST SUNDAY NIGHT...THEN SHIFT SLOWLY E OVER E
WA ON TUESDAY. WEAK LOW LEVEL OFFSHORE FLOW WILL PUT MAX TEMPS IN
THE 60S TO MID 70S MONDAY AND TUESDAY.

THE GFS...ECMWF...AND CANADIAN CONTINUE TO BE A BIT OF AN
INCONSISTENT MESS FROM TUESDAY NIGHT ONWARD. THERE IS BROAD
AGREEMENT THAT THE UPPER LEVEL RIDGE WILL DRIFT E AND A LARGE UPPER
LEVEL TROUGH WILL APPROACH THE COAST. MOIST S FLOW WILL DEVELOP OVER
W WA AHEAD OF THE TROUGH FOR SOME SHOWERS...BUT JUST WHEN THIS WILL
WILL OCCUR AND HOW IT WILL UNFOLD IS STILL IN DOUBT. SO FOR
NOW...THE TUESDAY NIGHT THROUGH THURSDAY PERIOD HAS A BROADBRUSH
CHANCE OF SHOWERS. KAM

&&

.AVIATION...HIGH PRESSURE OVER THE PAC NW WILL LEAD TO DRY AND
STABLE WEATHER ACROSS WESTERN WA TONIGHT. THE FLOW ALOFT IS
WESTERLY. VFR CONDITIONS WILL CONTINUE. A WEAK COLD FRONT WILL CROSS
THE AREA ON FRIDAY BUT THERE IS LITTLE MOISTURE ATTACHED WITH THIS
SYSTEM. EXPECT VFR CONDITIONS. 33

KSEA...FEW HIGH CLOUDS TONIGHT WITH LIGHT N/NE WINDS. 33

&&

.MARINE...HIGH PRESSURE WILL REMAIN OVER THE AREA TONIGHT. WEST
SWELLS ARE 10 TO 13 FT AND A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS
REMAINS IN EFFECT FOR THE COASTAL WATERS AND WESTERN STRAIT OF JUAN
DE FUCA. MEANWHILE...NORTH WINDS AT DESTRUCTION ARE STILL OVER 20 KT
BUT WINDS SHOULD EASE AFTER MIDNIGHT TONIGHT.

ONSHORE FLOW WILL INCREASE ON FRIDAY AS A COLD FRONT CROSSES WESTERN
WA. THE COASTAL WATERS WILL LIKELY SEE SMALL CRAFT ADVISORY
WINDS...WITH GALES POSSIBLE THROUGH THE CENTRAL AND EAST STRAIT.

LOW PRESSURE WILL FORM ALONG THE COAST THIS WEEKEND FOR NORTHERLY
FLOW. OFFSHORE FLOW WILL CONTINUE ON MONDAY. THE NEXT FRONT WILL
ARRIVE NEXT TUESDAY. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COAST AND WEST ENTRANCE FOR HAZARDOUS SEAS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.
     GALE WATCH FRIDAY EVENING CENTRAL AND EAST STRAIT.

&&

$$

WWW.WEATHER.GOV/SEATTLE

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















000
FXUS66 KSEW 162141
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
242 PM PDT THU APR 16 2015

.SYNOPSIS...AN UPPER LEVEL RIDGE WILL KEEP SKIES MOSTLY CLEAR
TONIGHT WITH COOL TEMPERATURES. A WEAK DRY UPPER LEVEL TROUGH WILL
BRING PERIODS OF CLOUDS TO WESTERN WASHINGTON ON FRIDAY. A STRONGER
UPPER LEVEL RIDGE WILL BRING MOSTLY SUNNY AND WARMER WEATHER
SATURDAY THROUGH TUESDAY. A LARGE UPPER LEVEL TROUGH WILL BRING
SHOWERS TO THE AREA TUESDAY NIGHT THROUGH THURSDAY.

&&

.SHORT TERM...THE LOW AMPLITUDE UPPER LEVEL RIDGE OVER W WA THIS
AFTERNOON WILL SLIDE E TONIGHT AS THE UPPER LEVEL SHORTWAVE TROUGH
OFFSHORE NEAR 45N/140W APPROACHES. THE AIR MASS IS DRY AND GOOD
RADIATIONAL COOLING TONIGHT MAY ALLOW THE COLDEST SPOTS TO REACH THE
MID TO UPPER 30S AGAIN FRIDAY MORNING.

THE UPPER LEVEL SHORTWAVE TROUGH OFFSHORE NEAR 45N/140W AT 20Z WILL
TRACK ACROSS THE AREA ON FRIDAY. MODELS HAVE CONTINUED TO KEEP THIS
FEATURE WEAK AND JUST ABOUT COMPLETELY DRY...SO ANY MENTION OF
SHOWERS HAS BEEN DROPPED FROM THE FORECAST. THE SKINNY REMNANTS OF
THE FRONTAL BAND WILL CROSS W WA DURING THE DAY...BUT CLOUD COVER
SHOULD BE MINIMAL ENOUGH TO MAINTAIN A MOSTLY SUNNY FORECAST.

THE APPROACHING TROUGH WILL PUSH AN AREA OF STRATUS OVER THE COASTAL
WATERS ON FRIDAY AS IT MOVES INLAND. MODERATE LOW LEVEL ONSHORE FLOW
WILL DEVELOP BEHIND THE SHORTWAVE TROUGH FRIDAY AFTERNOON AND
EVENING WHICH WILL SPREAD THE MOIST COASTAL AIR MASS INLAND. THE
06Z/12Z NAM IS NOW INDICATING MORE OF A NW PUSH WITH THE COASTAL
STRATUS...SO LESS LOW LEVEL MOISTURE SHOULD REACH THE PUGET SOUND
REGION. AT THIS POINT IT LOOKS LIKE THE COAST...STRAIT...AND SW
INTERIOR WILL SEE THE MOST STRATUS...WITH JUST PATCHY STRATUS OVER
PUGET SOUND. OF COURSE THERE IS STILL QUITE A BIT OF UNCERTAINTY
REGARDING THE LOW CLOUD COVERAGE. STRATUS OVER THE INTERIOR SHOULD
CLEAR RAPIDLY BEFORE SATURDAY AFTERNOON...WITH SUNNY SKIES AND
AFTERNOON MAX TEMPS IN THE 60S. STRATUS ON THE COAST SHOULD CLEAR
FROM THE N AS DRIER AIR MOVES IN.

A STRONGER UPPER LEVEL RIDGE WILL BUILD OFFSHORE ALONG 130W ON
SATURDAY...BEHIND THE DEPARTING TROUGH...THEN DOMINATE WEATHER
PATTERN THROUGH TUESDAY. THE AIR MASS WILL REMAIN DRY ON SUNDAY AND
GRADUAL WARMING SHOULD PRODUCE MAX TEMPS IN THE 60S TO LOWER 70S. KAM

.LONG TERM...THE UPPER LEVEL RIDGE AXIS WILL MOVE OVER THE COAST
SUNDAY NIGHT...THEN SHIFT SLOWLY E OVER E WA ON TUESDAY. WEAK LOW
LEVEL OFFSHORE FLOW WILL PUT MAX TEMPS IN THE 60S TO MID 70S MONDAY
AND TUESDAY.

THE GFS...ECMWF...AND CANADIAN CONTINUE TO BE A BIT OF AN
INCONSISTENT MESS FROM TUESDAY NIGHT ONWARD. THERE IS BROAD
AGREEMENT THAT THE UPPER LEVEL RIDGE WILL DRIFT E AND A LARGE UPPER
LEVEL TROUGH WILL APPROACH THE COAST. MOIST S FLOW WILL DEVELOP OVER
W WA AHEAD OF THE TROUGH FOR SOME SHOWERS...BUT JUST WHEN THIS WILL
WILL OCCUR AND HOW IT WILL UNFOLD IS STILL IN DOUBT. SO FOR
NOW...THE TUESDAY NIGHT THROUGH THURSDAY PERIOD HAS A BROADBRUSH
CHANCE OF SHOWERS. KAM

&&

.AVIATION...FLOW ALOFT IS WESTERLY AS A FLAT UPPER LEVEL RIDGE
REMAINS OVER THE PACIFIC NORTHWEST. ON FRIDAY A WEAK UPPER TROUGH
WILL MOVE THROUGH SOUTHERN BRITISH COLUMBIA. AIR MASS IS DRY AND
STABLE. AT THE SURFACE HIGH PRES OFFSHORE WILL GIVE WEAK ONSHORE
FLOW THIS EVENING. VFR CONDITIONS WILL CONTINUE.

KSEA...VFR CONDITIONS WITH ONLY SOME THIN HIGH CLOUDS AT TIMES.
NORTHERLY WIND 8-12 KT WILL EASE OVERNIGHT. CHB

&&

.MARINE...HIGH PRESSURE OVER WESTERN WA WILL BRING GENERALLY LIGHT
NORTHERLY WINDS TONIGHT. WESTERLY SWELLS OF 10 FT OR SO WILL REACH
THE COAST TONIGHT AND A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS IS
IN EFFECT FOR THE COAST AND WESTERN STRAIT.

ONSHORE FLOW WILL INCREASE ON FRIDAY AS A WEAK TROUGH CROSSES THE
AREA. SMALL CRAFT ADVISORY WINDS ARE LIKELY FOR THE COASTAL WATERS
AND THE STRAIT OF JUAN DE FUCA LATE FRIDAY AFTERNOON AND EVENING.
GALES ARE POSSIBLE IN THE STRAIT AND A GALE WATCH IS IN EFFECT FOR
FRIDAY AFTERNOON AND EVENING. NORTHERLY FLOW WILL DEVELOP SATURDAY
AND SUNDAY AS LOW PRES FORMS ALONG THE COAST. ONSHORE FLOW WILL
RETURN TUESDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COAST AND WEST ENTRANCE FOR HAZARDOUS SEAS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.
     GALE WATCH FRIDAY EVENING CENTRAL AND EAST STRAIT.

&&

$$

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












000
FXUS66 KSEW 162141
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
242 PM PDT THU APR 16 2015

.SYNOPSIS...AN UPPER LEVEL RIDGE WILL KEEP SKIES MOSTLY CLEAR
TONIGHT WITH COOL TEMPERATURES. A WEAK DRY UPPER LEVEL TROUGH WILL
BRING PERIODS OF CLOUDS TO WESTERN WASHINGTON ON FRIDAY. A STRONGER
UPPER LEVEL RIDGE WILL BRING MOSTLY SUNNY AND WARMER WEATHER
SATURDAY THROUGH TUESDAY. A LARGE UPPER LEVEL TROUGH WILL BRING
SHOWERS TO THE AREA TUESDAY NIGHT THROUGH THURSDAY.

&&

.SHORT TERM...THE LOW AMPLITUDE UPPER LEVEL RIDGE OVER W WA THIS
AFTERNOON WILL SLIDE E TONIGHT AS THE UPPER LEVEL SHORTWAVE TROUGH
OFFSHORE NEAR 45N/140W APPROACHES. THE AIR MASS IS DRY AND GOOD
RADIATIONAL COOLING TONIGHT MAY ALLOW THE COLDEST SPOTS TO REACH THE
MID TO UPPER 30S AGAIN FRIDAY MORNING.

THE UPPER LEVEL SHORTWAVE TROUGH OFFSHORE NEAR 45N/140W AT 20Z WILL
TRACK ACROSS THE AREA ON FRIDAY. MODELS HAVE CONTINUED TO KEEP THIS
FEATURE WEAK AND JUST ABOUT COMPLETELY DRY...SO ANY MENTION OF
SHOWERS HAS BEEN DROPPED FROM THE FORECAST. THE SKINNY REMNANTS OF
THE FRONTAL BAND WILL CROSS W WA DURING THE DAY...BUT CLOUD COVER
SHOULD BE MINIMAL ENOUGH TO MAINTAIN A MOSTLY SUNNY FORECAST.

THE APPROACHING TROUGH WILL PUSH AN AREA OF STRATUS OVER THE COASTAL
WATERS ON FRIDAY AS IT MOVES INLAND. MODERATE LOW LEVEL ONSHORE FLOW
WILL DEVELOP BEHIND THE SHORTWAVE TROUGH FRIDAY AFTERNOON AND
EVENING WHICH WILL SPREAD THE MOIST COASTAL AIR MASS INLAND. THE
06Z/12Z NAM IS NOW INDICATING MORE OF A NW PUSH WITH THE COASTAL
STRATUS...SO LESS LOW LEVEL MOISTURE SHOULD REACH THE PUGET SOUND
REGION. AT THIS POINT IT LOOKS LIKE THE COAST...STRAIT...AND SW
INTERIOR WILL SEE THE MOST STRATUS...WITH JUST PATCHY STRATUS OVER
PUGET SOUND. OF COURSE THERE IS STILL QUITE A BIT OF UNCERTAINTY
REGARDING THE LOW CLOUD COVERAGE. STRATUS OVER THE INTERIOR SHOULD
CLEAR RAPIDLY BEFORE SATURDAY AFTERNOON...WITH SUNNY SKIES AND
AFTERNOON MAX TEMPS IN THE 60S. STRATUS ON THE COAST SHOULD CLEAR
FROM THE N AS DRIER AIR MOVES IN.

A STRONGER UPPER LEVEL RIDGE WILL BUILD OFFSHORE ALONG 130W ON
SATURDAY...BEHIND THE DEPARTING TROUGH...THEN DOMINATE WEATHER
PATTERN THROUGH TUESDAY. THE AIR MASS WILL REMAIN DRY ON SUNDAY AND
GRADUAL WARMING SHOULD PRODUCE MAX TEMPS IN THE 60S TO LOWER 70S. KAM

.LONG TERM...THE UPPER LEVEL RIDGE AXIS WILL MOVE OVER THE COAST
SUNDAY NIGHT...THEN SHIFT SLOWLY E OVER E WA ON TUESDAY. WEAK LOW
LEVEL OFFSHORE FLOW WILL PUT MAX TEMPS IN THE 60S TO MID 70S MONDAY
AND TUESDAY.

THE GFS...ECMWF...AND CANADIAN CONTINUE TO BE A BIT OF AN
INCONSISTENT MESS FROM TUESDAY NIGHT ONWARD. THERE IS BROAD
AGREEMENT THAT THE UPPER LEVEL RIDGE WILL DRIFT E AND A LARGE UPPER
LEVEL TROUGH WILL APPROACH THE COAST. MOIST S FLOW WILL DEVELOP OVER
W WA AHEAD OF THE TROUGH FOR SOME SHOWERS...BUT JUST WHEN THIS WILL
WILL OCCUR AND HOW IT WILL UNFOLD IS STILL IN DOUBT. SO FOR
NOW...THE TUESDAY NIGHT THROUGH THURSDAY PERIOD HAS A BROADBRUSH
CHANCE OF SHOWERS. KAM

&&

.AVIATION...FLOW ALOFT IS WESTERLY AS A FLAT UPPER LEVEL RIDGE
REMAINS OVER THE PACIFIC NORTHWEST. ON FRIDAY A WEAK UPPER TROUGH
WILL MOVE THROUGH SOUTHERN BRITISH COLUMBIA. AIR MASS IS DRY AND
STABLE. AT THE SURFACE HIGH PRES OFFSHORE WILL GIVE WEAK ONSHORE
FLOW THIS EVENING. VFR CONDITIONS WILL CONTINUE.

KSEA...VFR CONDITIONS WITH ONLY SOME THIN HIGH CLOUDS AT TIMES.
NORTHERLY WIND 8-12 KT WILL EASE OVERNIGHT. CHB

&&

.MARINE...HIGH PRESSURE OVER WESTERN WA WILL BRING GENERALLY LIGHT
NORTHERLY WINDS TONIGHT. WESTERLY SWELLS OF 10 FT OR SO WILL REACH
THE COAST TONIGHT AND A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS IS
IN EFFECT FOR THE COAST AND WESTERN STRAIT.

ONSHORE FLOW WILL INCREASE ON FRIDAY AS A WEAK TROUGH CROSSES THE
AREA. SMALL CRAFT ADVISORY WINDS ARE LIKELY FOR THE COASTAL WATERS
AND THE STRAIT OF JUAN DE FUCA LATE FRIDAY AFTERNOON AND EVENING.
GALES ARE POSSIBLE IN THE STRAIT AND A GALE WATCH IS IN EFFECT FOR
FRIDAY AFTERNOON AND EVENING. NORTHERLY FLOW WILL DEVELOP SATURDAY
AND SUNDAY AS LOW PRES FORMS ALONG THE COAST. ONSHORE FLOW WILL
RETURN TUESDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COAST AND WEST ENTRANCE FOR HAZARDOUS SEAS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.
     GALE WATCH FRIDAY EVENING CENTRAL AND EAST STRAIT.

&&

$$

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













000
FXUS66 KSEW 162141
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
242 PM PDT THU APR 16 2015

.SYNOPSIS...AN UPPER LEVEL RIDGE WILL KEEP SKIES MOSTLY CLEAR
TONIGHT WITH COOL TEMPERATURES. A WEAK DRY UPPER LEVEL TROUGH WILL
BRING PERIODS OF CLOUDS TO WESTERN WASHINGTON ON FRIDAY. A STRONGER
UPPER LEVEL RIDGE WILL BRING MOSTLY SUNNY AND WARMER WEATHER
SATURDAY THROUGH TUESDAY. A LARGE UPPER LEVEL TROUGH WILL BRING
SHOWERS TO THE AREA TUESDAY NIGHT THROUGH THURSDAY.

&&

.SHORT TERM...THE LOW AMPLITUDE UPPER LEVEL RIDGE OVER W WA THIS
AFTERNOON WILL SLIDE E TONIGHT AS THE UPPER LEVEL SHORTWAVE TROUGH
OFFSHORE NEAR 45N/140W APPROACHES. THE AIR MASS IS DRY AND GOOD
RADIATIONAL COOLING TONIGHT MAY ALLOW THE COLDEST SPOTS TO REACH THE
MID TO UPPER 30S AGAIN FRIDAY MORNING.

THE UPPER LEVEL SHORTWAVE TROUGH OFFSHORE NEAR 45N/140W AT 20Z WILL
TRACK ACROSS THE AREA ON FRIDAY. MODELS HAVE CONTINUED TO KEEP THIS
FEATURE WEAK AND JUST ABOUT COMPLETELY DRY...SO ANY MENTION OF
SHOWERS HAS BEEN DROPPED FROM THE FORECAST. THE SKINNY REMNANTS OF
THE FRONTAL BAND WILL CROSS W WA DURING THE DAY...BUT CLOUD COVER
SHOULD BE MINIMAL ENOUGH TO MAINTAIN A MOSTLY SUNNY FORECAST.

THE APPROACHING TROUGH WILL PUSH AN AREA OF STRATUS OVER THE COASTAL
WATERS ON FRIDAY AS IT MOVES INLAND. MODERATE LOW LEVEL ONSHORE FLOW
WILL DEVELOP BEHIND THE SHORTWAVE TROUGH FRIDAY AFTERNOON AND
EVENING WHICH WILL SPREAD THE MOIST COASTAL AIR MASS INLAND. THE
06Z/12Z NAM IS NOW INDICATING MORE OF A NW PUSH WITH THE COASTAL
STRATUS...SO LESS LOW LEVEL MOISTURE SHOULD REACH THE PUGET SOUND
REGION. AT THIS POINT IT LOOKS LIKE THE COAST...STRAIT...AND SW
INTERIOR WILL SEE THE MOST STRATUS...WITH JUST PATCHY STRATUS OVER
PUGET SOUND. OF COURSE THERE IS STILL QUITE A BIT OF UNCERTAINTY
REGARDING THE LOW CLOUD COVERAGE. STRATUS OVER THE INTERIOR SHOULD
CLEAR RAPIDLY BEFORE SATURDAY AFTERNOON...WITH SUNNY SKIES AND
AFTERNOON MAX TEMPS IN THE 60S. STRATUS ON THE COAST SHOULD CLEAR
FROM THE N AS DRIER AIR MOVES IN.

A STRONGER UPPER LEVEL RIDGE WILL BUILD OFFSHORE ALONG 130W ON
SATURDAY...BEHIND THE DEPARTING TROUGH...THEN DOMINATE WEATHER
PATTERN THROUGH TUESDAY. THE AIR MASS WILL REMAIN DRY ON SUNDAY AND
GRADUAL WARMING SHOULD PRODUCE MAX TEMPS IN THE 60S TO LOWER 70S. KAM

.LONG TERM...THE UPPER LEVEL RIDGE AXIS WILL MOVE OVER THE COAST
SUNDAY NIGHT...THEN SHIFT SLOWLY E OVER E WA ON TUESDAY. WEAK LOW
LEVEL OFFSHORE FLOW WILL PUT MAX TEMPS IN THE 60S TO MID 70S MONDAY
AND TUESDAY.

THE GFS...ECMWF...AND CANADIAN CONTINUE TO BE A BIT OF AN
INCONSISTENT MESS FROM TUESDAY NIGHT ONWARD. THERE IS BROAD
AGREEMENT THAT THE UPPER LEVEL RIDGE WILL DRIFT E AND A LARGE UPPER
LEVEL TROUGH WILL APPROACH THE COAST. MOIST S FLOW WILL DEVELOP OVER
W WA AHEAD OF THE TROUGH FOR SOME SHOWERS...BUT JUST WHEN THIS WILL
WILL OCCUR AND HOW IT WILL UNFOLD IS STILL IN DOUBT. SO FOR
NOW...THE TUESDAY NIGHT THROUGH THURSDAY PERIOD HAS A BROADBRUSH
CHANCE OF SHOWERS. KAM

&&

.AVIATION...FLOW ALOFT IS WESTERLY AS A FLAT UPPER LEVEL RIDGE
REMAINS OVER THE PACIFIC NORTHWEST. ON FRIDAY A WEAK UPPER TROUGH
WILL MOVE THROUGH SOUTHERN BRITISH COLUMBIA. AIR MASS IS DRY AND
STABLE. AT THE SURFACE HIGH PRES OFFSHORE WILL GIVE WEAK ONSHORE
FLOW THIS EVENING. VFR CONDITIONS WILL CONTINUE.

KSEA...VFR CONDITIONS WITH ONLY SOME THIN HIGH CLOUDS AT TIMES.
NORTHERLY WIND 8-12 KT WILL EASE OVERNIGHT. CHB

&&

.MARINE...HIGH PRESSURE OVER WESTERN WA WILL BRING GENERALLY LIGHT
NORTHERLY WINDS TONIGHT. WESTERLY SWELLS OF 10 FT OR SO WILL REACH
THE COAST TONIGHT AND A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS IS
IN EFFECT FOR THE COAST AND WESTERN STRAIT.

ONSHORE FLOW WILL INCREASE ON FRIDAY AS A WEAK TROUGH CROSSES THE
AREA. SMALL CRAFT ADVISORY WINDS ARE LIKELY FOR THE COASTAL WATERS
AND THE STRAIT OF JUAN DE FUCA LATE FRIDAY AFTERNOON AND EVENING.
GALES ARE POSSIBLE IN THE STRAIT AND A GALE WATCH IS IN EFFECT FOR
FRIDAY AFTERNOON AND EVENING. NORTHERLY FLOW WILL DEVELOP SATURDAY
AND SUNDAY AS LOW PRES FORMS ALONG THE COAST. ONSHORE FLOW WILL
RETURN TUESDAY. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COAST AND WEST ENTRANCE FOR HAZARDOUS SEAS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.
     GALE WATCH FRIDAY EVENING CENTRAL AND EAST STRAIT.

&&

$$

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













000
FXUS66 KSEW 161546
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
846 AM PDT THU APR 16 2015

.SYNOPSIS...AN UPPER LEVEL RIDGE WILL BRING MOSTLY SUNNY DAYS TO
WESTERN WASHINGTON TODAY THROUGH TUESDAY. THE ONE EXCEPTION IS A
WEAK UPPER LEVEL TROUGH THAT WILL MOVE ACROSS BRITISH COLUMBIA LATE
FRIDAY AND FRIDAY NIGHT. THE TROUGH COULD PRODUCE SOME LIGHT SHOWERS
OVER THE CASCADES FRIDAY NIGHT AND BRING SOME CLOUDS TO THE AREA
FRIDAY THROUGH SATURDAY MORNING. THE WARM RIDGE WILL PUSH DAYTIME
HIGHS INTO THE 60S TO LOWER 70S SUNDAY THROUGH TUESDAY.

&&

.SHORT TERM...A FLAT UPPER LEVEL RIDGE WILL BUILD ENOUGH OVER W WA
TODAY TO KEEP THE WARM FRONT MOISTURE CURRENTLY MOVING ACROSS
VANCOUVER ISLAND TO THE N OF THE AREA. THIS MEANS SUNNY WEATHER
TODAY FOR W WA WITH HIGHS REACHING THE UPPER 50S TO MID 60S.

THE WEAK UPPER LEVEL SHORTWAVE TROUGH OFFSHORE NEAR 45N/144W IS
EXPECTED TO MOVE ACROSS THE REGION ON FRIDAY. MODELS OVER THE PAST
FEW DAYS HAVE TRENDED WEAKER AND DRIER WITH THIS SYSTEM...SO AT THIS
POINT THE CHANCE OF SHOWERS OVER THE CASCADES HAS BECOME
QUESTIONABLE. AS FAR AS CLOUDS...GFS/NAM AGREE THAT A SKINNY DRY
FRONTAL BAND WILL MOVE ACROSS W WA ON FRIDAY.

MODERATE ONSHORE FLOW IS EXPECTED TO DEVELOP FRIDAY AFTERNOON AS THE
TROUGH CROSSES THE REGION...BUT THE LATEST 12Z NAM IS NOW INDICATING
MORE OF A NW PUSH WHICH TYPICALLY BRINGS MUCH LESS STRATUS TO THE
INTERIOR. THIS WOULD MEAN THAT GETTING STRATUS OVER PUGET SOUND
SATURDAY MORNING WOULD REQUIRE MOIST LOW LEVEL AIR TO MAKE IT ALL
THE WAY E THROUGH THE STRAIT SO THAN N FLOW CAN PUSH IT S OVER N
PUGET SOUND. WHATEVER SHALLOW STRATUS FORMS OVER THE AREA SATURDAY
MORNING SHOULD DISSIPATE QUICKLY BEFORE AFTERNOON...LEAVING SATURDAY
AFTERNOON SUNNY AND WARM WITH MAX TEMPS IN THE 60S.

DRY NW FLOW ALOFT WILL DEVELOP FRIDAY NIGHT BEHIND THE DEPARTING
UPPER LEVEL SHORTWAVE TROUGH. A STRONGER UPPER LEVEL RIDGE BUILDING
OFFSHORE WILL DOMINATE THE REGIONS WEATHER THROUGH TUESDAY. KAM

.LONG TERM...PREVIOUS DISCUSSION FROM THE 3 AM AFD...THE UPPER RIDGE
WILL WEAKEN SLIGHTLY AS IT MOVES SLOWLY INTO THE OFFSHORE WATERS
SUNDAY AND THEN INLAND MONDAY AND TUESDAY. THE LOWER REACHES OF THE
AIR MASS WILL BE A LITTLE WARMER AS THE RIDGE MOVES INLAND...WITH
HIGHS IN THE MID 60S TO LOWER 70S ACROSS MOST OF WESTERN WASHINGTON.

THE MODELS ARE IN ROUGH AGREEMENT THAT MOIST SOUTHERLY FLOW WILL
DEVELOP OVER THE AREA LATE TUESDAY OR TUESDAY NIGHT...AS THE UPPER
RIDGE MOVES EAST AND A DEEP UPPER LOW MOVES SOUTHEAST WELL OFFSHORE.
THAT SHOULD PRODUCE SOME SHOWERS OVER THE FORECAST AREA...ESPECIALLY
OVER THE HIGHER TERRAIN.   MCDONNAL

&&

.AVIATION...FLOW ALOFT IS WESTERLY AS A FLAT UPPER LEVEL RIDGE
REMAINS OVER THE PACIFIC NORTHWEST. AIR MASS IS DRY AND STABLE. AT
THE SURFACE HIGH PRES OFFSHORE WILL GIVE WEAK ONSHORE FLOW THIS
AFTERNOON. VFR CONDITIONS WILL CONTINUE.

KSEA...VFR CONDITIONS WITH ONLY SOME THIN HIGH CLOUDS AT TIMES.
LIGHT WIND WILL BECOME NORTHERLY 4-8 KT IN THE AFTERNOON. CHB

&&

.MARINE...HIGH PRESSURE OVER WESTERN WA WILL BRING GENERALLY LIGHT
WINDS THROUGH TONIGHT. WEST SWELLS WILL BUILD TO 10-13 FT TODAY AND
A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS IS IN EFFECT FOR THE
COASTAL WATERS AND WESTERN STRAIT OF JUAN DE FUCA. ONSHORE FLOW WILL
INCREASE ON FRIDAY AS A WEAK COLD FRONT CROSSES THE AREA. SMALL
CRAFT ADVISORY WINDS ARE LIKELY FOR THE COASTAL WATERS AND THE
STRAIT OF JUAN DE FUCA LATE FRIDAY AFTERNOON AND EVENING. GALES ARE
POSSIBLE IN THE STRAIT. NORTHERLY FLOW WILL DEVELOP SATURDAY AND
SUNDAY AS LOW PRES FORMS ALONG THE COAST. CHB

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COAST AND WEST ENTRANCE FOR HAZARDOUS SEAS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.

&&

$$

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









000
FXUS66 KSEW 160953
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 AM PDT THU APR 16 2015

.SYNOPSIS...AN UPPER RIDGE WILL BRING MOSTLY SUNNY DAYS TO WESTERN
WASHINGTON TODAY THROUGH TUESDAY. ONE EXCEPTION IS A WEAK UPPER
TROUGH MOVING THROUGH BRITISH COLUMBIA LATE FRIDAY AND FRIDAY NIGHT
WHICH COULD PRODUCE SOME LIGHT SHOWERS OVER THE CASCADES. HIGHS WILL
BE IN THE UPPER 50S TO 60S THROUGH SATURDAY...AND IN THE 60S TO
LOWER 70S SUNDAY THROUGH TUESDAY. SHOWERS ARE POSSIBLE WEDNESDAY.

&&

.SHORT TERM...AN UPPER RIDGE REMAINS OVER WASHINGTON EARLY THIS
MORNING...EXTENDING ACROSS THE AREA FROM THE UPPER HIGH CENTERED
WELL OFFSHORE OF CALIFORNIA. A WARM FRONT IS ALONG THE BRITISH
COLUMBIA COAST WITH A FRONTAL BOUNDARY EXTENDING SOUTHWEST ALONG THE
NORTHWEST SIDE OF THE RIDGE. THE RIDGE IS KEEPING SKIES OVER WESTERN
WASHINGTON MOSTLY CLEAR...AND 2 AM TEMPERATURES RANGED FROM THE MID
30S TO THE UPPER 40S. LIGHT PATCHY FOG WILL PROBABLY DEVELOP OVER
THE SOUTH PUGET SOUND REGION...SOUTHWEST INTERIOR...AND LOWER
CHEHALIS VALLEY AROUND SUNRISE.

THE UPPER RIDGE WILL BUILD NORTHWARD OVER THE AREA TODAY...PUSHING
THE FRONTAL BAND FURTHER AWAY FROM THE FORECAST AREA. THE FORECAST
AREA SHOULD HAVE LOTS OF SUNSHINE TODAY. THE AIR MASS WILL BE
SEVERAL DEGREES WARMER THAN IT WAS WEDNESDAY...WITH A LIGHT
NORTHWEST PRESSURE GRADIENT ACROSS WESTERN WASHINGTON. HIGHS TODAY
SHOULD BE IN THE UPPER 50S TO 60S.

THE UPPER RIDGE WILL PROGRESS EAST OF THE AREA TONIGHT...AND THE
WEAK UPPER TROUGH WITH THE FRONTAL SYSTEM TO OUR NORTH WILL BRUSH
WESTERN WASHINGTON AS IT MOVES THROUGH BRITISH COLUMBIA LATE FRIDAY.
THE TROUGH WILL BRING SOME MID LEVEL MOISTURE AND INCREASE LOW LEVEL
ONSHORE FLOW...RESULTING IN SOME CLOUD COVER ESPECIALLY AT THE COAST
AND IN THE MOUNTAINS. BUT IT WILL STILL BE A PARTLY TO MOSTLY SUNNY
DAY...AND HIGHS AGAIN WILL BE IN THE UPPER 50S TO 60S.

A STRONGER OFFSHORE UPPER RIDGE WILL BUILD ALONG 130W SATURDAY...
WITH DRIER NORTHWEST FLOW ALOFT. LOW LEVEL FLOW WILL VEER TO
NORTHWESTERLY AS WELL. ANY LOW CLOUD COVER LINGERING IN THE MORNING
SHOULD BE SHORT LIVED...AND SATURDAY WILL BE ANOTHER DAY OF SUNNY
AND SLIGHTLY WARMER WEATHER.   MCDONNAL

.LONG TERM...THE UPPER RIDGE WILL WEAKEN SLIGHTLY AS IT MOVES SLOWLY
INTO THE OFFSHORE WATERS SUNDAY AND THEN INLAND MONDAY AND TUESDAY.
THE LOWER REACHES OF THE AIR MASS WILL BE A LITTLE WARMER AS THE
RIDGE MOVES INLAND...WITH HIGHS IN THE MID 60S TO LOWER 70S ACROSS
MOST OF WESTERN WASHINGTON.

THE MODELS ARE IN ROUGH AGREEMENT THAT MOIST SOUTHERLY FLOW WILL
DEVELOP OVER THE AREA LATE TUESDAY OR TUESDAY NIGHT...AS THE UPPER
RIDGE MOVES EAST AND A DEEP UPPER LOW MOVES SOUTHEAST WELL OFFSHORE.
THAT SHOULD PRODUCE SOME SHOWERS OVER THE FORECAST AREA...ESPECIALLY
OVER THE HIGHER TERRAIN.   MCDONNAL

&&

.AVIATION...AN UPPER LEVEL RIDGE OVER THE PAC NW WILL MAINTAIN DRY
AND STABLE WEATHER ACROSS WESTERN WA TODAY. THE FLOW ALOFT IS
WESTERLY. VFR CONDITIONS WILL CONTINUE. 33

KSEA...FEW CIRRUS CLOUDS ALOFT THIS MORNING WITH VFR CONDITIONS.
LIGHT N/NE WINDS AT THE SURFACE. 33

&&

.MARINE...HIGH PRESSURE OVER WESTERN WA WILL BRING GENERALLY LIGHT
WINDS THROUGH TONIGHT. MEANWHILE...WEST SWELLS WILL BUILD TO 10-13
FT TODAY AND A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS IS IN EFFECT
FOR THE COASTAL WATERS AND WESTERN STRAIT OF JUAN DE FUCA. ONSHORE
FLOW WILL INCREASE ON FRIDAY AS A COLD FRONT CROSSES WESTERN WA.
SMALL CRAFT ADVISORY WINDS ARE LIKELY FOR THE COASTAL WATERS AND THE
STRAIT OF JUAN DE FUCA LATE FRIDAY AFTERNOON AND EVENING. NORTHERLY
FLOW WILL DEVELOP SATURDAY AND SUNDAY AS LOW PRES FORMS ALONG THE
COAST. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COASTAL WATERS FOR HAZARDOUS SEAS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.

&&

$$

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







000
FXUS66 KSEW 160953
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 AM PDT THU APR 16 2015

.SYNOPSIS...AN UPPER RIDGE WILL BRING MOSTLY SUNNY DAYS TO WESTERN
WASHINGTON TODAY THROUGH TUESDAY. ONE EXCEPTION IS A WEAK UPPER
TROUGH MOVING THROUGH BRITISH COLUMBIA LATE FRIDAY AND FRIDAY NIGHT
WHICH COULD PRODUCE SOME LIGHT SHOWERS OVER THE CASCADES. HIGHS WILL
BE IN THE UPPER 50S TO 60S THROUGH SATURDAY...AND IN THE 60S TO
LOWER 70S SUNDAY THROUGH TUESDAY. SHOWERS ARE POSSIBLE WEDNESDAY.

&&

.SHORT TERM...AN UPPER RIDGE REMAINS OVER WASHINGTON EARLY THIS
MORNING...EXTENDING ACROSS THE AREA FROM THE UPPER HIGH CENTERED
WELL OFFSHORE OF CALIFORNIA. A WARM FRONT IS ALONG THE BRITISH
COLUMBIA COAST WITH A FRONTAL BOUNDARY EXTENDING SOUTHWEST ALONG THE
NORTHWEST SIDE OF THE RIDGE. THE RIDGE IS KEEPING SKIES OVER WESTERN
WASHINGTON MOSTLY CLEAR...AND 2 AM TEMPERATURES RANGED FROM THE MID
30S TO THE UPPER 40S. LIGHT PATCHY FOG WILL PROBABLY DEVELOP OVER
THE SOUTH PUGET SOUND REGION...SOUTHWEST INTERIOR...AND LOWER
CHEHALIS VALLEY AROUND SUNRISE.

THE UPPER RIDGE WILL BUILD NORTHWARD OVER THE AREA TODAY...PUSHING
THE FRONTAL BAND FURTHER AWAY FROM THE FORECAST AREA. THE FORECAST
AREA SHOULD HAVE LOTS OF SUNSHINE TODAY. THE AIR MASS WILL BE
SEVERAL DEGREES WARMER THAN IT WAS WEDNESDAY...WITH A LIGHT
NORTHWEST PRESSURE GRADIENT ACROSS WESTERN WASHINGTON. HIGHS TODAY
SHOULD BE IN THE UPPER 50S TO 60S.

THE UPPER RIDGE WILL PROGRESS EAST OF THE AREA TONIGHT...AND THE
WEAK UPPER TROUGH WITH THE FRONTAL SYSTEM TO OUR NORTH WILL BRUSH
WESTERN WASHINGTON AS IT MOVES THROUGH BRITISH COLUMBIA LATE FRIDAY.
THE TROUGH WILL BRING SOME MID LEVEL MOISTURE AND INCREASE LOW LEVEL
ONSHORE FLOW...RESULTING IN SOME CLOUD COVER ESPECIALLY AT THE COAST
AND IN THE MOUNTAINS. BUT IT WILL STILL BE A PARTLY TO MOSTLY SUNNY
DAY...AND HIGHS AGAIN WILL BE IN THE UPPER 50S TO 60S.

A STRONGER OFFSHORE UPPER RIDGE WILL BUILD ALONG 130W SATURDAY...
WITH DRIER NORTHWEST FLOW ALOFT. LOW LEVEL FLOW WILL VEER TO
NORTHWESTERLY AS WELL. ANY LOW CLOUD COVER LINGERING IN THE MORNING
SHOULD BE SHORT LIVED...AND SATURDAY WILL BE ANOTHER DAY OF SUNNY
AND SLIGHTLY WARMER WEATHER.   MCDONNAL

.LONG TERM...THE UPPER RIDGE WILL WEAKEN SLIGHTLY AS IT MOVES SLOWLY
INTO THE OFFSHORE WATERS SUNDAY AND THEN INLAND MONDAY AND TUESDAY.
THE LOWER REACHES OF THE AIR MASS WILL BE A LITTLE WARMER AS THE
RIDGE MOVES INLAND...WITH HIGHS IN THE MID 60S TO LOWER 70S ACROSS
MOST OF WESTERN WASHINGTON.

THE MODELS ARE IN ROUGH AGREEMENT THAT MOIST SOUTHERLY FLOW WILL
DEVELOP OVER THE AREA LATE TUESDAY OR TUESDAY NIGHT...AS THE UPPER
RIDGE MOVES EAST AND A DEEP UPPER LOW MOVES SOUTHEAST WELL OFFSHORE.
THAT SHOULD PRODUCE SOME SHOWERS OVER THE FORECAST AREA...ESPECIALLY
OVER THE HIGHER TERRAIN.   MCDONNAL

&&

.AVIATION...AN UPPER LEVEL RIDGE OVER THE PAC NW WILL MAINTAIN DRY
AND STABLE WEATHER ACROSS WESTERN WA TODAY. THE FLOW ALOFT IS
WESTERLY. VFR CONDITIONS WILL CONTINUE. 33

KSEA...FEW CIRRUS CLOUDS ALOFT THIS MORNING WITH VFR CONDITIONS.
LIGHT N/NE WINDS AT THE SURFACE. 33

&&

.MARINE...HIGH PRESSURE OVER WESTERN WA WILL BRING GENERALLY LIGHT
WINDS THROUGH TONIGHT. MEANWHILE...WEST SWELLS WILL BUILD TO 10-13
FT TODAY AND A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS IS IN EFFECT
FOR THE COASTAL WATERS AND WESTERN STRAIT OF JUAN DE FUCA. ONSHORE
FLOW WILL INCREASE ON FRIDAY AS A COLD FRONT CROSSES WESTERN WA.
SMALL CRAFT ADVISORY WINDS ARE LIKELY FOR THE COASTAL WATERS AND THE
STRAIT OF JUAN DE FUCA LATE FRIDAY AFTERNOON AND EVENING. NORTHERLY
FLOW WILL DEVELOP SATURDAY AND SUNDAY AS LOW PRES FORMS ALONG THE
COAST. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COASTAL WATERS FOR HAZARDOUS SEAS.
     SMALL CRAFT ADVISORY FOR ROUGH GRAYS HARBOR BAR.

&&

$$

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






000
FXUS66 KSEW 160447
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
945 PM PDT WED APR 15 2015

.SYNOPSIS...AN UPPER LEVEL RIDGE AND SURFACE HIGH WILL REMAIN OVER
WESTERN WASHINGTON THROUGH THURSDAY FOR DRY WEATHER. A WARM FRONT
OVER BRITISH COLUMBIA WILL BRING CLOUDS TO THE NORTH PART TONIGHT.
THE RIDGE WILL BUILD NORTHWARD THURSDAY...BRINGING WARMER WEATHER
AND MORE SUNSHINE. A WEAK UPPER LEVEL TROUGH WILL BRING CLOUDS OVER
THE AREA FRIDAY...AND A CHANCE OF SHOWERS TO THE NORTH COAST AND
NORTH CASCADES FRIDAY AFTERNOON AND EVENING. A STRONGER UPPER LEVEL
RIDGE WILL BRING SUNNY WARMER WEATHER SATURDAY AFTERNOON THROUGH
TUESDAY.

&&

.SHORT TERM...SATELLITE IMAGERY SHOWS FLAT UPPER LEVEL RIDGE OVER
WESTERN WASHINGTON THIS EVENING. WARM FRONT WELL TO THE NORTH OF THE
AREA WITH HIGH CLOUDS ASSOCIATED WITH THE FRONT OVER THE NORTHERN
PORTION OF THE AREA. WITH THE LACK OF CLOUD COVER A WIDE VARIETY OF
TEMPERATURES AT 9 PM ACROSS THE AREA...UPPER 30S TO MID 50S.

NO CHANGES IN THE FORECAST TONIGHT WITH THE 00Z MODELS SHOWING THE
RIDGE HOLDING IN PLACE THROUGH THURSDAY KEEPING THE WARM FRONT NORTH
OF THE AREA. SURFACE GRADIENTS TRENDING OFFSHORE TONIGHT WILL SWITCH
BACK AROUND TO NORTHWESTERLY ONSHORE ON THURSDAY. TEMPERATURES ALOFT
WARMING UP WITH THE 850 MB TEMPS NEAR 0 THIS EVENING WARMING TO
AROUND PLUS 5C BY 00Z FRIDAY. WITH PLENTY OF SUNSHINE THIS WILL
RESULT IN ABOUT 5 DEGREES OF WARMING VERSUS TODAY. LOWER TO MID 60S
WILL BE COMMON OVER THE INTERIOR.

SOME CHANGES TAKING PLACE THURSDAY NIGHT WITH THE RIDGE AXIS
SHIFTING EAST. UPPER LEVEL TROUGH OFFSHORE NEAR 130W BY 12Z FRIDAY.
NOT CLOSE ENOUGH TO PROVIDE ANY WEATHER TO THE AREA. EXPECT LOWS IN
THE UPPER 30S TO MID 40S.

UPPER LEVEL TROUGH MOVING INTO WESTERN WASHINGTON ON FRIDAY BUT THE
TROUGH IS FAIRLY WEAK...500 MB HEIGHTS ONLY LOWER INTO THE MID TO
UPPER 560 DMS. SURFACE GRADIENTS TURN ONSHORE IN THE MORNING BUT
WITH THE WEAK LIFT ASSOCIATED WITH THE TROUGH THE ONLY CHANCES FOR
SHOWERS LOOK TO BE ALONG THE NORTH COAST...OLYMPICS AND NORTH
CASCADES. EVEN WITH THE TROUGH OVERHEAD MOS GUIDANCE FOR FRIDAY A
COUPLE OF DEGREES WARMER VERSUS THURSDAY.

TROUGH MOVING EAST OF THE AREA FRIDAY NIGHT WITH AN UPPER LEVEL
RIDGE BUILDING QUICKLY OFFSHORE. SURFACE GRADIENTS GO NORTHWESTERLY
FRIDAY NIGHT AND REMAIN NORTHWESTERLY THROUGH SATURDAY MORNING.
MODEL BOUNDARY LEVEL RH SATURATED SATURDAY MORNING. WITH THE
NORTHWESTERLY SURFACE GRADIENTS EXPECT THIS LAYER TO BE QUITE
SHALLOW. CURRENT FORECAST HAS SOME CLOUD COVER OVER THE INTERIOR
SATURDAY MORNING. IF THE MODEL TRENDS CONTINUE LOOK FOR THE THIS TO
BE TAKEN OUT OF THE FORECAST. FELTON

.LONG TERM...PREVIOUS DISCUSSION FOLLOWS. LONG RANGE MODELS START
BREAKING THE RIDGE DOWN STARTING SUNDAY...WHILE IT REMAINS OVER THE
REGION. BY TUESDAY AFTERNOON...WITH THE RIDGE AXIS OVER THE ID
PANHANDLE...A LARGE UPPER LEVEL TROUGH WILL HAVE FORMED JUST
OFFSHORE. S FLOW ALOFT WILL DEVELOP OVER W WA WITH MOISTURE
INCREASING AT SOME POINT. MODELS ARE STRUGGLING WITH CONSISTENCY
REGARDING THE STRUCTURE OF THE TROUGH AND WHEN AND HOW MUCH MOISTURE
WILL MOVE N OVER W WA. FOR NOW THE FORECASTS FOLLOW A ROUGH BLEND OF
THE GFS AND ECMWF WITH A CHANCE OF SHOWERS OVER W WA TUESDAY NIGHT
AND WEDNESDAY. KAM

&&

.AVIATION...AN UPPER LEVEL RIDGE OVER THE PAC NW WILL MAINTAIN DRY
AND STABLE WEATHER ACROSS WESTERN WA TONIGHT THROUGH THURSDAY. THE
FLOW ALOFT IS WESTERLY. VFR CONDITIONS WILL PREVAIL. 33

KSEA...FEW-SCT CIRRUS CLOUDS ALOFT WITH VFR CONDITIONS. LIGHT N/NE
WINDS AT THE SURFACE. 33

&&

.MARINE...HIGH PRESSURE OVER WESTERN WA WILL BRING GENERALLY LIGHT
WINDS THROUGH THURSDAY. MEANWHILE...WEST SWELL WILL INCREASE TO
10 FT TONIGHT AND A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE OUTER
COASTAL WATER ZONES. ONSHORE FLOW WILL INCREASE ON FRIDAY AS A COLD
FRONT CROSSES WESTERN WA. SMALL CRAFT ADVISORY WINDS ARE LIKELY FOR
THE COASTAL WATERS AND THE STRAIT OF JUAN DE FUCA. NORTHERLY FLOW
WILL DEVELOP ON SATURDAY AS LOW PRES FORMS ALONG THE COAST.
NORTHERLY FLOW WILL CONTINUE THROUGH EARLY NEXT WEEK. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY OUTER COASTAL WATERS FOR HAZARDOUS SEAS.

&&

$$

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















000
FXUS66 KSEW 160447
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
945 PM PDT WED APR 15 2015

.SYNOPSIS...AN UPPER LEVEL RIDGE AND SURFACE HIGH WILL REMAIN OVER
WESTERN WASHINGTON THROUGH THURSDAY FOR DRY WEATHER. A WARM FRONT
OVER BRITISH COLUMBIA WILL BRING CLOUDS TO THE NORTH PART TONIGHT.
THE RIDGE WILL BUILD NORTHWARD THURSDAY...BRINGING WARMER WEATHER
AND MORE SUNSHINE. A WEAK UPPER LEVEL TROUGH WILL BRING CLOUDS OVER
THE AREA FRIDAY...AND A CHANCE OF SHOWERS TO THE NORTH COAST AND
NORTH CASCADES FRIDAY AFTERNOON AND EVENING. A STRONGER UPPER LEVEL
RIDGE WILL BRING SUNNY WARMER WEATHER SATURDAY AFTERNOON THROUGH
TUESDAY.

&&

.SHORT TERM...SATELLITE IMAGERY SHOWS FLAT UPPER LEVEL RIDGE OVER
WESTERN WASHINGTON THIS EVENING. WARM FRONT WELL TO THE NORTH OF THE
AREA WITH HIGH CLOUDS ASSOCIATED WITH THE FRONT OVER THE NORTHERN
PORTION OF THE AREA. WITH THE LACK OF CLOUD COVER A WIDE VARIETY OF
TEMPERATURES AT 9 PM ACROSS THE AREA...UPPER 30S TO MID 50S.

NO CHANGES IN THE FORECAST TONIGHT WITH THE 00Z MODELS SHOWING THE
RIDGE HOLDING IN PLACE THROUGH THURSDAY KEEPING THE WARM FRONT NORTH
OF THE AREA. SURFACE GRADIENTS TRENDING OFFSHORE TONIGHT WILL SWITCH
BACK AROUND TO NORTHWESTERLY ONSHORE ON THURSDAY. TEMPERATURES ALOFT
WARMING UP WITH THE 850 MB TEMPS NEAR 0 THIS EVENING WARMING TO
AROUND PLUS 5C BY 00Z FRIDAY. WITH PLENTY OF SUNSHINE THIS WILL
RESULT IN ABOUT 5 DEGREES OF WARMING VERSUS TODAY. LOWER TO MID 60S
WILL BE COMMON OVER THE INTERIOR.

SOME CHANGES TAKING PLACE THURSDAY NIGHT WITH THE RIDGE AXIS
SHIFTING EAST. UPPER LEVEL TROUGH OFFSHORE NEAR 130W BY 12Z FRIDAY.
NOT CLOSE ENOUGH TO PROVIDE ANY WEATHER TO THE AREA. EXPECT LOWS IN
THE UPPER 30S TO MID 40S.

UPPER LEVEL TROUGH MOVING INTO WESTERN WASHINGTON ON FRIDAY BUT THE
TROUGH IS FAIRLY WEAK...500 MB HEIGHTS ONLY LOWER INTO THE MID TO
UPPER 560 DMS. SURFACE GRADIENTS TURN ONSHORE IN THE MORNING BUT
WITH THE WEAK LIFT ASSOCIATED WITH THE TROUGH THE ONLY CHANCES FOR
SHOWERS LOOK TO BE ALONG THE NORTH COAST...OLYMPICS AND NORTH
CASCADES. EVEN WITH THE TROUGH OVERHEAD MOS GUIDANCE FOR FRIDAY A
COUPLE OF DEGREES WARMER VERSUS THURSDAY.

TROUGH MOVING EAST OF THE AREA FRIDAY NIGHT WITH AN UPPER LEVEL
RIDGE BUILDING QUICKLY OFFSHORE. SURFACE GRADIENTS GO NORTHWESTERLY
FRIDAY NIGHT AND REMAIN NORTHWESTERLY THROUGH SATURDAY MORNING.
MODEL BOUNDARY LEVEL RH SATURATED SATURDAY MORNING. WITH THE
NORTHWESTERLY SURFACE GRADIENTS EXPECT THIS LAYER TO BE QUITE
SHALLOW. CURRENT FORECAST HAS SOME CLOUD COVER OVER THE INTERIOR
SATURDAY MORNING. IF THE MODEL TRENDS CONTINUE LOOK FOR THE THIS TO
BE TAKEN OUT OF THE FORECAST. FELTON

.LONG TERM...PREVIOUS DISCUSSION FOLLOWS. LONG RANGE MODELS START
BREAKING THE RIDGE DOWN STARTING SUNDAY...WHILE IT REMAINS OVER THE
REGION. BY TUESDAY AFTERNOON...WITH THE RIDGE AXIS OVER THE ID
PANHANDLE...A LARGE UPPER LEVEL TROUGH WILL HAVE FORMED JUST
OFFSHORE. S FLOW ALOFT WILL DEVELOP OVER W WA WITH MOISTURE
INCREASING AT SOME POINT. MODELS ARE STRUGGLING WITH CONSISTENCY
REGARDING THE STRUCTURE OF THE TROUGH AND WHEN AND HOW MUCH MOISTURE
WILL MOVE N OVER W WA. FOR NOW THE FORECASTS FOLLOW A ROUGH BLEND OF
THE GFS AND ECMWF WITH A CHANCE OF SHOWERS OVER W WA TUESDAY NIGHT
AND WEDNESDAY. KAM

&&

.AVIATION...AN UPPER LEVEL RIDGE OVER THE PAC NW WILL MAINTAIN DRY
AND STABLE WEATHER ACROSS WESTERN WA TONIGHT THROUGH THURSDAY. THE
FLOW ALOFT IS WESTERLY. VFR CONDITIONS WILL PREVAIL. 33

KSEA...FEW-SCT CIRRUS CLOUDS ALOFT WITH VFR CONDITIONS. LIGHT N/NE
WINDS AT THE SURFACE. 33

&&

.MARINE...HIGH PRESSURE OVER WESTERN WA WILL BRING GENERALLY LIGHT
WINDS THROUGH THURSDAY. MEANWHILE...WEST SWELL WILL INCREASE TO
10 FT TONIGHT AND A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE OUTER
COASTAL WATER ZONES. ONSHORE FLOW WILL INCREASE ON FRIDAY AS A COLD
FRONT CROSSES WESTERN WA. SMALL CRAFT ADVISORY WINDS ARE LIKELY FOR
THE COASTAL WATERS AND THE STRAIT OF JUAN DE FUCA. NORTHERLY FLOW
WILL DEVELOP ON SATURDAY AS LOW PRES FORMS ALONG THE COAST.
NORTHERLY FLOW WILL CONTINUE THROUGH EARLY NEXT WEEK. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY OUTER COASTAL WATERS FOR HAZARDOUS SEAS.

&&

$$

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
















000
FXUS66 KSEW 160447
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
945 PM PDT WED APR 15 2015

.SYNOPSIS...AN UPPER LEVEL RIDGE AND SURFACE HIGH WILL REMAIN OVER
WESTERN WASHINGTON THROUGH THURSDAY FOR DRY WEATHER. A WARM FRONT
OVER BRITISH COLUMBIA WILL BRING CLOUDS TO THE NORTH PART TONIGHT.
THE RIDGE WILL BUILD NORTHWARD THURSDAY...BRINGING WARMER WEATHER
AND MORE SUNSHINE. A WEAK UPPER LEVEL TROUGH WILL BRING CLOUDS OVER
THE AREA FRIDAY...AND A CHANCE OF SHOWERS TO THE NORTH COAST AND
NORTH CASCADES FRIDAY AFTERNOON AND EVENING. A STRONGER UPPER LEVEL
RIDGE WILL BRING SUNNY WARMER WEATHER SATURDAY AFTERNOON THROUGH
TUESDAY.

&&

.SHORT TERM...SATELLITE IMAGERY SHOWS FLAT UPPER LEVEL RIDGE OVER
WESTERN WASHINGTON THIS EVENING. WARM FRONT WELL TO THE NORTH OF THE
AREA WITH HIGH CLOUDS ASSOCIATED WITH THE FRONT OVER THE NORTHERN
PORTION OF THE AREA. WITH THE LACK OF CLOUD COVER A WIDE VARIETY OF
TEMPERATURES AT 9 PM ACROSS THE AREA...UPPER 30S TO MID 50S.

NO CHANGES IN THE FORECAST TONIGHT WITH THE 00Z MODELS SHOWING THE
RIDGE HOLDING IN PLACE THROUGH THURSDAY KEEPING THE WARM FRONT NORTH
OF THE AREA. SURFACE GRADIENTS TRENDING OFFSHORE TONIGHT WILL SWITCH
BACK AROUND TO NORTHWESTERLY ONSHORE ON THURSDAY. TEMPERATURES ALOFT
WARMING UP WITH THE 850 MB TEMPS NEAR 0 THIS EVENING WARMING TO
AROUND PLUS 5C BY 00Z FRIDAY. WITH PLENTY OF SUNSHINE THIS WILL
RESULT IN ABOUT 5 DEGREES OF WARMING VERSUS TODAY. LOWER TO MID 60S
WILL BE COMMON OVER THE INTERIOR.

SOME CHANGES TAKING PLACE THURSDAY NIGHT WITH THE RIDGE AXIS
SHIFTING EAST. UPPER LEVEL TROUGH OFFSHORE NEAR 130W BY 12Z FRIDAY.
NOT CLOSE ENOUGH TO PROVIDE ANY WEATHER TO THE AREA. EXPECT LOWS IN
THE UPPER 30S TO MID 40S.

UPPER LEVEL TROUGH MOVING INTO WESTERN WASHINGTON ON FRIDAY BUT THE
TROUGH IS FAIRLY WEAK...500 MB HEIGHTS ONLY LOWER INTO THE MID TO
UPPER 560 DMS. SURFACE GRADIENTS TURN ONSHORE IN THE MORNING BUT
WITH THE WEAK LIFT ASSOCIATED WITH THE TROUGH THE ONLY CHANCES FOR
SHOWERS LOOK TO BE ALONG THE NORTH COAST...OLYMPICS AND NORTH
CASCADES. EVEN WITH THE TROUGH OVERHEAD MOS GUIDANCE FOR FRIDAY A
COUPLE OF DEGREES WARMER VERSUS THURSDAY.

TROUGH MOVING EAST OF THE AREA FRIDAY NIGHT WITH AN UPPER LEVEL
RIDGE BUILDING QUICKLY OFFSHORE. SURFACE GRADIENTS GO NORTHWESTERLY
FRIDAY NIGHT AND REMAIN NORTHWESTERLY THROUGH SATURDAY MORNING.
MODEL BOUNDARY LEVEL RH SATURATED SATURDAY MORNING. WITH THE
NORTHWESTERLY SURFACE GRADIENTS EXPECT THIS LAYER TO BE QUITE
SHALLOW. CURRENT FORECAST HAS SOME CLOUD COVER OVER THE INTERIOR
SATURDAY MORNING. IF THE MODEL TRENDS CONTINUE LOOK FOR THE THIS TO
BE TAKEN OUT OF THE FORECAST. FELTON

.LONG TERM...PREVIOUS DISCUSSION FOLLOWS. LONG RANGE MODELS START
BREAKING THE RIDGE DOWN STARTING SUNDAY...WHILE IT REMAINS OVER THE
REGION. BY TUESDAY AFTERNOON...WITH THE RIDGE AXIS OVER THE ID
PANHANDLE...A LARGE UPPER LEVEL TROUGH WILL HAVE FORMED JUST
OFFSHORE. S FLOW ALOFT WILL DEVELOP OVER W WA WITH MOISTURE
INCREASING AT SOME POINT. MODELS ARE STRUGGLING WITH CONSISTENCY
REGARDING THE STRUCTURE OF THE TROUGH AND WHEN AND HOW MUCH MOISTURE
WILL MOVE N OVER W WA. FOR NOW THE FORECASTS FOLLOW A ROUGH BLEND OF
THE GFS AND ECMWF WITH A CHANCE OF SHOWERS OVER W WA TUESDAY NIGHT
AND WEDNESDAY. KAM

&&

.AVIATION...AN UPPER LEVEL RIDGE OVER THE PAC NW WILL MAINTAIN DRY
AND STABLE WEATHER ACROSS WESTERN WA TONIGHT THROUGH THURSDAY. THE
FLOW ALOFT IS WESTERLY. VFR CONDITIONS WILL PREVAIL. 33

KSEA...FEW-SCT CIRRUS CLOUDS ALOFT WITH VFR CONDITIONS. LIGHT N/NE
WINDS AT THE SURFACE. 33

&&

.MARINE...HIGH PRESSURE OVER WESTERN WA WILL BRING GENERALLY LIGHT
WINDS THROUGH THURSDAY. MEANWHILE...WEST SWELL WILL INCREASE TO
10 FT TONIGHT AND A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE OUTER
COASTAL WATER ZONES. ONSHORE FLOW WILL INCREASE ON FRIDAY AS A COLD
FRONT CROSSES WESTERN WA. SMALL CRAFT ADVISORY WINDS ARE LIKELY FOR
THE COASTAL WATERS AND THE STRAIT OF JUAN DE FUCA. NORTHERLY FLOW
WILL DEVELOP ON SATURDAY AS LOW PRES FORMS ALONG THE COAST.
NORTHERLY FLOW WILL CONTINUE THROUGH EARLY NEXT WEEK. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY OUTER COASTAL WATERS FOR HAZARDOUS SEAS.

&&

$$

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















000
FXUS66 KSEW 160447
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
945 PM PDT WED APR 15 2015

.SYNOPSIS...AN UPPER LEVEL RIDGE AND SURFACE HIGH WILL REMAIN OVER
WESTERN WASHINGTON THROUGH THURSDAY FOR DRY WEATHER. A WARM FRONT
OVER BRITISH COLUMBIA WILL BRING CLOUDS TO THE NORTH PART TONIGHT.
THE RIDGE WILL BUILD NORTHWARD THURSDAY...BRINGING WARMER WEATHER
AND MORE SUNSHINE. A WEAK UPPER LEVEL TROUGH WILL BRING CLOUDS OVER
THE AREA FRIDAY...AND A CHANCE OF SHOWERS TO THE NORTH COAST AND
NORTH CASCADES FRIDAY AFTERNOON AND EVENING. A STRONGER UPPER LEVEL
RIDGE WILL BRING SUNNY WARMER WEATHER SATURDAY AFTERNOON THROUGH
TUESDAY.

&&

.SHORT TERM...SATELLITE IMAGERY SHOWS FLAT UPPER LEVEL RIDGE OVER
WESTERN WASHINGTON THIS EVENING. WARM FRONT WELL TO THE NORTH OF THE
AREA WITH HIGH CLOUDS ASSOCIATED WITH THE FRONT OVER THE NORTHERN
PORTION OF THE AREA. WITH THE LACK OF CLOUD COVER A WIDE VARIETY OF
TEMPERATURES AT 9 PM ACROSS THE AREA...UPPER 30S TO MID 50S.

NO CHANGES IN THE FORECAST TONIGHT WITH THE 00Z MODELS SHOWING THE
RIDGE HOLDING IN PLACE THROUGH THURSDAY KEEPING THE WARM FRONT NORTH
OF THE AREA. SURFACE GRADIENTS TRENDING OFFSHORE TONIGHT WILL SWITCH
BACK AROUND TO NORTHWESTERLY ONSHORE ON THURSDAY. TEMPERATURES ALOFT
WARMING UP WITH THE 850 MB TEMPS NEAR 0 THIS EVENING WARMING TO
AROUND PLUS 5C BY 00Z FRIDAY. WITH PLENTY OF SUNSHINE THIS WILL
RESULT IN ABOUT 5 DEGREES OF WARMING VERSUS TODAY. LOWER TO MID 60S
WILL BE COMMON OVER THE INTERIOR.

SOME CHANGES TAKING PLACE THURSDAY NIGHT WITH THE RIDGE AXIS
SHIFTING EAST. UPPER LEVEL TROUGH OFFSHORE NEAR 130W BY 12Z FRIDAY.
NOT CLOSE ENOUGH TO PROVIDE ANY WEATHER TO THE AREA. EXPECT LOWS IN
THE UPPER 30S TO MID 40S.

UPPER LEVEL TROUGH MOVING INTO WESTERN WASHINGTON ON FRIDAY BUT THE
TROUGH IS FAIRLY WEAK...500 MB HEIGHTS ONLY LOWER INTO THE MID TO
UPPER 560 DMS. SURFACE GRADIENTS TURN ONSHORE IN THE MORNING BUT
WITH THE WEAK LIFT ASSOCIATED WITH THE TROUGH THE ONLY CHANCES FOR
SHOWERS LOOK TO BE ALONG THE NORTH COAST...OLYMPICS AND NORTH
CASCADES. EVEN WITH THE TROUGH OVERHEAD MOS GUIDANCE FOR FRIDAY A
COUPLE OF DEGREES WARMER VERSUS THURSDAY.

TROUGH MOVING EAST OF THE AREA FRIDAY NIGHT WITH AN UPPER LEVEL
RIDGE BUILDING QUICKLY OFFSHORE. SURFACE GRADIENTS GO NORTHWESTERLY
FRIDAY NIGHT AND REMAIN NORTHWESTERLY THROUGH SATURDAY MORNING.
MODEL BOUNDARY LEVEL RH SATURATED SATURDAY MORNING. WITH THE
NORTHWESTERLY SURFACE GRADIENTS EXPECT THIS LAYER TO BE QUITE
SHALLOW. CURRENT FORECAST HAS SOME CLOUD COVER OVER THE INTERIOR
SATURDAY MORNING. IF THE MODEL TRENDS CONTINUE LOOK FOR THE THIS TO
BE TAKEN OUT OF THE FORECAST. FELTON

.LONG TERM...PREVIOUS DISCUSSION FOLLOWS. LONG RANGE MODELS START
BREAKING THE RIDGE DOWN STARTING SUNDAY...WHILE IT REMAINS OVER THE
REGION. BY TUESDAY AFTERNOON...WITH THE RIDGE AXIS OVER THE ID
PANHANDLE...A LARGE UPPER LEVEL TROUGH WILL HAVE FORMED JUST
OFFSHORE. S FLOW ALOFT WILL DEVELOP OVER W WA WITH MOISTURE
INCREASING AT SOME POINT. MODELS ARE STRUGGLING WITH CONSISTENCY
REGARDING THE STRUCTURE OF THE TROUGH AND WHEN AND HOW MUCH MOISTURE
WILL MOVE N OVER W WA. FOR NOW THE FORECASTS FOLLOW A ROUGH BLEND OF
THE GFS AND ECMWF WITH A CHANCE OF SHOWERS OVER W WA TUESDAY NIGHT
AND WEDNESDAY. KAM

&&

.AVIATION...AN UPPER LEVEL RIDGE OVER THE PAC NW WILL MAINTAIN DRY
AND STABLE WEATHER ACROSS WESTERN WA TONIGHT THROUGH THURSDAY. THE
FLOW ALOFT IS WESTERLY. VFR CONDITIONS WILL PREVAIL. 33

KSEA...FEW-SCT CIRRUS CLOUDS ALOFT WITH VFR CONDITIONS. LIGHT N/NE
WINDS AT THE SURFACE. 33

&&

.MARINE...HIGH PRESSURE OVER WESTERN WA WILL BRING GENERALLY LIGHT
WINDS THROUGH THURSDAY. MEANWHILE...WEST SWELL WILL INCREASE TO
10 FT TONIGHT AND A SMALL CRAFT ADVISORY IS IN EFFECT FOR THE OUTER
COASTAL WATER ZONES. ONSHORE FLOW WILL INCREASE ON FRIDAY AS A COLD
FRONT CROSSES WESTERN WA. SMALL CRAFT ADVISORY WINDS ARE LIKELY FOR
THE COASTAL WATERS AND THE STRAIT OF JUAN DE FUCA. NORTHERLY FLOW
WILL DEVELOP ON SATURDAY AS LOW PRES FORMS ALONG THE COAST.
NORTHERLY FLOW WILL CONTINUE THROUGH EARLY NEXT WEEK. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY OUTER COASTAL WATERS FOR HAZARDOUS SEAS.

&&

$$

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
















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