Home > Products > Valid Products > AFD

000
FXUS66 KSEW 302202
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
301 PM PDT MON MAR 30 2015

.SYNOPSIS...A COLD FRONT WILL SPREAD RAIN ACROSS THE AREA TONIGHT
FOLLOWED BY AN UPPER LEVEL TROUGH TUESDAY FOR SHOWERS AND COOLER
WEATHER. SHOWERS WILL DIMINISH THURSDAY AS WEAK RIDGING BUILDS OVER
THE AREA AHEAD OF A FRONTAL SYSTEM THAT WILL AFFECT THE AREA ON
FRIDAY. AN UPPER LEVEL LOW WILL MAINTAIN A CHANCE OF SHOWERS THROUGH
THE WEEKEND.

&&

.SHORT TERM...A WARM FRONT REMAINS OVER SOUTHERN B.C. THIS AFTERNOON
WITH WESTERN WA IN THE WARM SECTOR. AS A RESULT...TEMPS ARE PRETTY
MILD ACROSS THE REGION WITH HIGHS MAINLY IN THE 60S. SOUTH WINDS ARE
INCREASING AS THE COLD FRONT STARTS TO SLIDE S/SE INTO WESTERN WA.
THIS FRONT WILL BRING WETTER WEATHER TO THE REGION TONIGHT AS IT
MOVES IN. RAIN WILL MAINLY AFFECT THE COAST THIS EVENING...WITH RAIN
SPREADING INTO THE INTERIOR NEAR MIDNIGHT TONIGHT. THERE IS PLENTY
OF MOISTURE WITH THIS FRONT AND WE WILL SEE WETTING RAINS ACROSS THE
BOARD.

AN UPPER LEVEL TROUGH AND ONSHORE FLOW WILL MAINTAIN COOL AND
SHOWERY WEATHER THROUGH TUESDAY. SNOW LEVELS WILL DROP TO AROUND
3000 FT WITH A FEW INCHES OF SNOW IN THE MOUNTAINS. A PUGET SOUND
CONVERGENCE ZONE MAY ENHANCE AMOUNTS IN KING COUNTY. MODELS ALSO
SHOW A NEGATIVE LIFTED INDEX AND CANNOT RULE OUT ISOLATED
THUNDERSTORMS TUE AFTERNOON. HIGHS ON TUE WILL BE IN THE LOW TO MID
50S - A FEW DEGREES BELOW NORMAL.

THE AIR MASS WILL REMAIN COOL AND UNSTABLE AS WE HEAD INTO WEDNESDAY
WITH A TROUGH STILL OVERHEAD. LOW LEVEL ONSHORE FLOW WILL PREVAIL
FOR SCATTERED SHOWERS. THE AIR MASS WILL STABILIZE AND DRY OUT AS WE
MOVE INTO THURSDAY. BY THEN A WEAK UPPER LEVEL RIDGE WILL BUILD OVER
THE PAC NW. 33

.LONG TERM...THE NEXT PACIFIC FRONTAL SYSTEM WILL ARRIVE ON FRIDAY
FOR ANOTHER PERIOD OF WET WEATHER ACROSS WESTERN WA. POPS WERE
NUDGED UPWARDS AS BOTH THE GFS AND ECMWF SHOW SIGNS OF AGREEMENT.
THE FORECAST THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK REMAINS
UNSETTLED AS AN UPPER LEVEL LOW SPINS OFFSHORE. THIS SYSTEM WILL
CONTINUE PUMPING MOISTURE INLAND FOR A CHANCE OF SHOWERS EACH DAY.
THE AIR MASS WILL REMAIN COOL WITH TEMPS SLIGHTLY BELOW NORMAL. 33

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A COLD FRONT ALONG 130W AT 21Z WILL REACH THE WA COAST
AROUND 05Z THEN CROSS THE INTERIOR AROUND 09Z. MOIST WESTERLY
ONSHORE FLOW WILL DEVELOP BEHIND THE FRONT. FLOW ALOFT WILL BE SW.
THE AIR MASS WAS FAIRLY DRY AND STABLE AT 21Z WITH GOOD VFR
CONDITIONS EVERYWHERE EXCEPT FOR MVFR CIGS ALONG THE COAST. CIGS
THROUGHOUT W WA ARE EXPECTED TO LOWER TO MVFR TONIGHT IN RAIN WITH
AND BEHIND THE COLD FRONT. GUSTY S SURFACE WINDS WILL DEVELOP
TONIGHT AHEAD OF THE FRONT AND WILL BE GUSTY IN SPOTS LATE TONIGHT.

A BROAD UPPER LEVEL TROUGH WILL MOVE OVER W WA BY TUESDAY AFTERNOON
WITH THE AIR MASS BECOMING UNSTABLE...WITH SHOWERS AND A CHANCE OF
THUNDERSTORMS.

KSEA...GOOD VFR CONDITIONS ARE EXPECTED THROUGH 05Z TONIGHT WITH
CIGS LOWERING TO BKN030-050 WITH RAIN AS A COLD FRONT REACHES THE
AREA ROUGHLY 07Z-09Z. MVFR CIGS ARE EXPECTED LATE TONIGHT. SURFACE
WINDS WILL REMAIN S-SW 6-12 KT THROUGH 06Z THEN RISE TO SW 15-25 KT
BEHIND THE FRONT. KAM

&&

.MARINE...A COLD FRONT ALONG 130W AT 21Z WILL REACH THE COAST LATE
THIS EVENING THE MOVE ACROSS THE INLAND WATERS A LITTLE AFTER
MIDNIGHT. STRONG ONSHORE FLOW WILL DEVELOP THROUGH THE STRAIT
IMMEDIATELY BEHIND THE FRONT. TONIGHTS FORECAST WAS BASED ON THE
MORNING HRRR MODEL RUNS WHICH IS THE ONLY MODEL THAT IS NOW
CONSISTENTLY INDICATING GALE FORCE WINDS IN THE STRAIT. THE 12Z
CANADIAN LAM ALSO SHOWS A COUPLE OF AREAS OF GALES. SCA S WINDS ARE
EXPECTED OVER THE INLAND WATERS AND OVER THE COAST TONIGHT AND
TUESDAY MORNING.

WEAKER ONSHORE FLOW WILL PREVAIL WEDNESDAY AND THURSDAY AS A RIDGE
BUILDS OFFSHORE. THERE SHOULD BE ENOUGH W PRESSURE GRADIENT THROUGH
THE STRAIT FOR SCA WINDS IN THE EVENINGS. ANOTHER COLD FRONT WILL
PROBABLY REACH THE AREA FRIDAY. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COASTAL WATERS...ENTRANCES TO THE
       STRAIT...ADMIRALTY INLET...NORTHERN INLAND WATERS...PUGET
       SOUND AND HOOD CANAL.
     GALE WARNING CENTRAL STRAIT OF JUAN DE FUCA AND EAST ENTRANCE.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.

&&

$$

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







000
FXUS66 KSEW 302202
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
301 PM PDT MON MAR 30 2015

.SYNOPSIS...A COLD FRONT WILL SPREAD RAIN ACROSS THE AREA TONIGHT
FOLLOWED BY AN UPPER LEVEL TROUGH TUESDAY FOR SHOWERS AND COOLER
WEATHER. SHOWERS WILL DIMINISH THURSDAY AS WEAK RIDGING BUILDS OVER
THE AREA AHEAD OF A FRONTAL SYSTEM THAT WILL AFFECT THE AREA ON
FRIDAY. AN UPPER LEVEL LOW WILL MAINTAIN A CHANCE OF SHOWERS THROUGH
THE WEEKEND.

&&

.SHORT TERM...A WARM FRONT REMAINS OVER SOUTHERN B.C. THIS AFTERNOON
WITH WESTERN WA IN THE WARM SECTOR. AS A RESULT...TEMPS ARE PRETTY
MILD ACROSS THE REGION WITH HIGHS MAINLY IN THE 60S. SOUTH WINDS ARE
INCREASING AS THE COLD FRONT STARTS TO SLIDE S/SE INTO WESTERN WA.
THIS FRONT WILL BRING WETTER WEATHER TO THE REGION TONIGHT AS IT
MOVES IN. RAIN WILL MAINLY AFFECT THE COAST THIS EVENING...WITH RAIN
SPREADING INTO THE INTERIOR NEAR MIDNIGHT TONIGHT. THERE IS PLENTY
OF MOISTURE WITH THIS FRONT AND WE WILL SEE WETTING RAINS ACROSS THE
BOARD.

AN UPPER LEVEL TROUGH AND ONSHORE FLOW WILL MAINTAIN COOL AND
SHOWERY WEATHER THROUGH TUESDAY. SNOW LEVELS WILL DROP TO AROUND
3000 FT WITH A FEW INCHES OF SNOW IN THE MOUNTAINS. A PUGET SOUND
CONVERGENCE ZONE MAY ENHANCE AMOUNTS IN KING COUNTY. MODELS ALSO
SHOW A NEGATIVE LIFTED INDEX AND CANNOT RULE OUT ISOLATED
THUNDERSTORMS TUE AFTERNOON. HIGHS ON TUE WILL BE IN THE LOW TO MID
50S - A FEW DEGREES BELOW NORMAL.

THE AIR MASS WILL REMAIN COOL AND UNSTABLE AS WE HEAD INTO WEDNESDAY
WITH A TROUGH STILL OVERHEAD. LOW LEVEL ONSHORE FLOW WILL PREVAIL
FOR SCATTERED SHOWERS. THE AIR MASS WILL STABILIZE AND DRY OUT AS WE
MOVE INTO THURSDAY. BY THEN A WEAK UPPER LEVEL RIDGE WILL BUILD OVER
THE PAC NW. 33

.LONG TERM...THE NEXT PACIFIC FRONTAL SYSTEM WILL ARRIVE ON FRIDAY
FOR ANOTHER PERIOD OF WET WEATHER ACROSS WESTERN WA. POPS WERE
NUDGED UPWARDS AS BOTH THE GFS AND ECMWF SHOW SIGNS OF AGREEMENT.
THE FORECAST THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK REMAINS
UNSETTLED AS AN UPPER LEVEL LOW SPINS OFFSHORE. THIS SYSTEM WILL
CONTINUE PUMPING MOISTURE INLAND FOR A CHANCE OF SHOWERS EACH DAY.
THE AIR MASS WILL REMAIN COOL WITH TEMPS SLIGHTLY BELOW NORMAL. 33

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A COLD FRONT ALONG 130W AT 21Z WILL REACH THE WA COAST
AROUND 05Z THEN CROSS THE INTERIOR AROUND 09Z. MOIST WESTERLY
ONSHORE FLOW WILL DEVELOP BEHIND THE FRONT. FLOW ALOFT WILL BE SW.
THE AIR MASS WAS FAIRLY DRY AND STABLE AT 21Z WITH GOOD VFR
CONDITIONS EVERYWHERE EXCEPT FOR MVFR CIGS ALONG THE COAST. CIGS
THROUGHOUT W WA ARE EXPECTED TO LOWER TO MVFR TONIGHT IN RAIN WITH
AND BEHIND THE COLD FRONT. GUSTY S SURFACE WINDS WILL DEVELOP
TONIGHT AHEAD OF THE FRONT AND WILL BE GUSTY IN SPOTS LATE TONIGHT.

A BROAD UPPER LEVEL TROUGH WILL MOVE OVER W WA BY TUESDAY AFTERNOON
WITH THE AIR MASS BECOMING UNSTABLE...WITH SHOWERS AND A CHANCE OF
THUNDERSTORMS.

KSEA...GOOD VFR CONDITIONS ARE EXPECTED THROUGH 05Z TONIGHT WITH
CIGS LOWERING TO BKN030-050 WITH RAIN AS A COLD FRONT REACHES THE
AREA ROUGHLY 07Z-09Z. MVFR CIGS ARE EXPECTED LATE TONIGHT. SURFACE
WINDS WILL REMAIN S-SW 6-12 KT THROUGH 06Z THEN RISE TO SW 15-25 KT
BEHIND THE FRONT. KAM

&&

.MARINE...A COLD FRONT ALONG 130W AT 21Z WILL REACH THE COAST LATE
THIS EVENING THE MOVE ACROSS THE INLAND WATERS A LITTLE AFTER
MIDNIGHT. STRONG ONSHORE FLOW WILL DEVELOP THROUGH THE STRAIT
IMMEDIATELY BEHIND THE FRONT. TONIGHTS FORECAST WAS BASED ON THE
MORNING HRRR MODEL RUNS WHICH IS THE ONLY MODEL THAT IS NOW
CONSISTENTLY INDICATING GALE FORCE WINDS IN THE STRAIT. THE 12Z
CANADIAN LAM ALSO SHOWS A COUPLE OF AREAS OF GALES. SCA S WINDS ARE
EXPECTED OVER THE INLAND WATERS AND OVER THE COAST TONIGHT AND
TUESDAY MORNING.

WEAKER ONSHORE FLOW WILL PREVAIL WEDNESDAY AND THURSDAY AS A RIDGE
BUILDS OFFSHORE. THERE SHOULD BE ENOUGH W PRESSURE GRADIENT THROUGH
THE STRAIT FOR SCA WINDS IN THE EVENINGS. ANOTHER COLD FRONT WILL
PROBABLY REACH THE AREA FRIDAY. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COASTAL WATERS...ENTRANCES TO THE
       STRAIT...ADMIRALTY INLET...NORTHERN INLAND WATERS...PUGET
       SOUND AND HOOD CANAL.
     GALE WARNING CENTRAL STRAIT OF JUAN DE FUCA AND EAST ENTRANCE.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.

&&

$$

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






000
FXUS66 KSEW 301602
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
902 AM PDT MON MAR 30 2015

.SYNOPSIS...WARM AIR ADVECTION WILL KEEP RAIN AT TIMES OVER THE
COAST AND NORTHERN INTERIOR TODAY. A COLD FRONT WILL SPREAD RAIN
ACROSS THE AREA TONIGHT FOLLOWED BY AN UPPER LEVEL TROUGH TUESDAY
FOR SHOWERS AND COOLER WEATHER. SHOWERS WILL DIMINISH THURSDAY AS
WEAK RIDGING BUILDS OVER THE AREA AHEAD OF A FRONTAL SYSTEM THAT
WILL AFFECT THE AREA ON FRIDAY.

&&

.SHORT TERM...A WARM FRONT OVER SOUTHERN B.C. IS CLIPPING WESTERN WA
THIS MORNING WITH A FEW LIGHT SHOWERS ALONG THE COAST AND NEAR THE
CANADIAN BORDER. THE INTERIOR WILL REMAIN DRY AND MOSTLY CLOUDY. THE
AIR MASS IS PRETTY MILD AND WE WILL SEE TEMPS IN THE LOW TO MID 60S
TODAY. THE CURRENT FORECAST IS ON TRACK.

THE COLD FRONT WILL SLIDE S/SE TONIGHT FOR A PERIOD OF WETTER
WEATHER ACROSS WESTERN WA. RAIN WILL MAINLY AFFECT THE COAST THIS
EVENING...WITH RAIN IN THE INTERIOR AFTER MIDNIGHT TONIGHT. THE
UPPER LEVEL TROUGH AND ONSHORE FLOW WILL MAINTAIN COOL AND SHOWERY
WEATHER THROUGH TUESDAY. SNOW LEVELS WILL DROP TO AROUND 3000 FT
WITH A FEW INCHES OF SNOW IN THE MOUNTAINS. A PUGET SOUND
CONVERGENCE ZONE MAY ENHANCE AMOUNTS. MODELS ALSO SHOW A NEGATIVE
LIFTED INDEX AND CANNOT RULE OUT ISOLATED THUNDERSTORMS TUE
AFTERNOON. HIGHS ON TUE WILL BE IN THE LOW TO MID 50S - A FEW
DEGREES BELOW NORMAL.

THE AIR MASS WILL REMAIN COOL AND UNSTABLE AS WE HEAD INTO WEDNESDAY
WITH A TROUGH STILL OVERHEAD. LOW LEVEL ONSHORE FLOW WILL PREVAIL
FOR SCATTERED SHOWERS. 33

.LONG TERM...PREVIOUS DISCUSSION...MEDIUM RANGE MODELS CONTINUE TO
SHOW UPPER LEVEL RIDGING ON THURSDAY AS A DEEP UPPER LEVEL LOW MOVES
INTO THE GULF OF ALASKA. THE BRIEF RIDGING ON THURSDAY WILL LIKELY
GIVE THE A BREAK IN THE SHOWERS BEFORE A FRONT ARRIVES FRIDAY. BOTH
THE GFS AND ECMWF DIFFER ON THE TRACK OF THE TRAILING UPPER LEVEL
LOW. THE EUROPEAN BRINGS IT DOWN THE NORTHWEST COAST BEFORE OPENING
UP AND MOVING INTO NORTHERN CALIFORNIA MONDAY NIGHT. THE GFS TAKES A
MUCH MORE PROGRESSIVE TACK...OPENING THE LOW UP AND BRINGING IT INTO
BRITISH COLUMBIA SATURDAY AFTERNOON. THE CURRENT FORECAST CONTINUES
TO REFLECT A COOL AND UNSETTLED PATTERN THROUGH THE WEEKEND.

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&


.AVIATION...A BROAD LOW AMPLITUDE UPPER LEVEL RIDGE CENTERED OVER ID
AT 15Z WILL MOVE OVER W MT BY 00Z. A COLD FRONT ALONG 130W AT 15Z
WILL APPROACH THE COAST THIS AFTERNOON...REACHING THE N COAST AROUND
03Z AND CROSSING PUGET SOUND AROUND 06Z. SW FLOW ALOFT WILL INCREASE
AS THE FRONT APPROACHES.

THE AIR MASS OVER W WA IS SOMEWHAT MOIST AND STABLE WITH CIGS MAINLY
SCT-BKN050-070 WITH HIGHER LAYERS. PATCHY MVFR/IFR CIGS MAINLY OVER
S PUGET SOUND AND THE SW INTERIOR SHOULD DISSIPATE BY 18Z.

CIGS ARE EXPECTED TO LOWER TO MVFR LEVELS TONIGHT AS THE COLD FRONT
MOVES ACROSS THE AREA. ONSHORE FLOW BEHIND THE FRONT WILL KEEP CIGS
MVFR WITH LOCAL IFR POSSIBLE TUESDAY MORNING. S WINDS THROUGH THE
INTERIOR WILL BECOME GUSTY BY THIS AFTERNOON AS THE FRONT APPROACHES.

KSEA...VFR CONDITIONS WILL CONTINUE THROUGH 03Z WITH CLOUD LAYERS
SCT-BKN060 AND HIGHER. CIGS ARE EXPECTED TO LOWER TO MVFR AS THE
COLD FRONT APPROACHES...THEN CROSSES PUGET SOUND AROUND 06Z. SURFACE
WINDS WILL BE S-SW 6-12 KT. KAM

&&

.MARINE...A SMALL SURFACE RIDGE WILL REMAIN OVER W WA TODAY...WHILE
AN OFFSHORE COLD FRONT APPROACHES THE COAST. THE COLD FRONT WILL
REACH THE N COAST THIS EVENING AROUND 8 PM THEN CROSS PUGET SOUND
BEFORE MIDNIGHT. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR S WINDS
AHEAD OF THE FRONT FOR BOTH THE COAST AND INLAND WATERS. THE LATEST
MESOSCALE MODELS HAVE BACKED OFF SLIGHTLY ON THE S WINDS THROUGH THE
INLAND WATERS TODAY WITH POCKETS OF WINDS PEAKING CLOSE TO 20 KT.

STRONG WESTERLY ONSHORE FLOW WILL DEVELOP IN THE STRAIT IMMEDIATELY
BEHIND THE FRONT TONIGHT. A GALE WARNING IS IN EFFECT. THERE REMAINS
A DIFFERENCE BETWEEN THE MODELS REGARDING WIND SPEEDS. THE GFS40
UIL-BLI PRESSURE GRADIENT REACHES BETWEEN 4 AND 5 MB WHICH WOULD BE
ENOUGH FOR GALE FORCE WINDS. HOWEVER ALL THE MESOSCALE MODELS
INCLUDING THE 06Z CANADIAN LAM TOP THE WINDS AT 30 KT FOR A HIGH END
SCA.

WEAKER ONSHORE FLOW WILL PREVAIL WEDNESDAY AND THURSDAY AS A RIDGE
BUILDS OFFSHORE. THERE SHOULD BE ENOUGH W PRESSURE GRADIENT THROUGH
THE STRAIT FOR SCA WINDS IN THE EVENINGS. ANOTHER COLD FRONT WILL
PROBABLY REACH THE AREA FRIDAY.

THERE WILL BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS THROUGH TUESDAY. BAR CONDITIONS WILL BE ROUGH AS WELL.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COASTAL WATERS...ENTRANCES TO THE
       STRAIT...ADMIRALTY INLET...NORTHERN INLAND WATERS...PUGET
       SOUND AND HOOD CANAL.
     GALE WARNING CENTRAL STRAIT OF JUAN DE FUCA AND EAST ENTRANCE
       STRAIT THIS EVENING THROUGH TUESDAY AFTERNOON.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.

&&

$$

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






000
FXUS66 KSEW 301602
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
902 AM PDT MON MAR 30 2015

.SYNOPSIS...WARM AIR ADVECTION WILL KEEP RAIN AT TIMES OVER THE
COAST AND NORTHERN INTERIOR TODAY. A COLD FRONT WILL SPREAD RAIN
ACROSS THE AREA TONIGHT FOLLOWED BY AN UPPER LEVEL TROUGH TUESDAY
FOR SHOWERS AND COOLER WEATHER. SHOWERS WILL DIMINISH THURSDAY AS
WEAK RIDGING BUILDS OVER THE AREA AHEAD OF A FRONTAL SYSTEM THAT
WILL AFFECT THE AREA ON FRIDAY.

&&

.SHORT TERM...A WARM FRONT OVER SOUTHERN B.C. IS CLIPPING WESTERN WA
THIS MORNING WITH A FEW LIGHT SHOWERS ALONG THE COAST AND NEAR THE
CANADIAN BORDER. THE INTERIOR WILL REMAIN DRY AND MOSTLY CLOUDY. THE
AIR MASS IS PRETTY MILD AND WE WILL SEE TEMPS IN THE LOW TO MID 60S
TODAY. THE CURRENT FORECAST IS ON TRACK.

THE COLD FRONT WILL SLIDE S/SE TONIGHT FOR A PERIOD OF WETTER
WEATHER ACROSS WESTERN WA. RAIN WILL MAINLY AFFECT THE COAST THIS
EVENING...WITH RAIN IN THE INTERIOR AFTER MIDNIGHT TONIGHT. THE
UPPER LEVEL TROUGH AND ONSHORE FLOW WILL MAINTAIN COOL AND SHOWERY
WEATHER THROUGH TUESDAY. SNOW LEVELS WILL DROP TO AROUND 3000 FT
WITH A FEW INCHES OF SNOW IN THE MOUNTAINS. A PUGET SOUND
CONVERGENCE ZONE MAY ENHANCE AMOUNTS. MODELS ALSO SHOW A NEGATIVE
LIFTED INDEX AND CANNOT RULE OUT ISOLATED THUNDERSTORMS TUE
AFTERNOON. HIGHS ON TUE WILL BE IN THE LOW TO MID 50S - A FEW
DEGREES BELOW NORMAL.

THE AIR MASS WILL REMAIN COOL AND UNSTABLE AS WE HEAD INTO WEDNESDAY
WITH A TROUGH STILL OVERHEAD. LOW LEVEL ONSHORE FLOW WILL PREVAIL
FOR SCATTERED SHOWERS. 33

.LONG TERM...PREVIOUS DISCUSSION...MEDIUM RANGE MODELS CONTINUE TO
SHOW UPPER LEVEL RIDGING ON THURSDAY AS A DEEP UPPER LEVEL LOW MOVES
INTO THE GULF OF ALASKA. THE BRIEF RIDGING ON THURSDAY WILL LIKELY
GIVE THE A BREAK IN THE SHOWERS BEFORE A FRONT ARRIVES FRIDAY. BOTH
THE GFS AND ECMWF DIFFER ON THE TRACK OF THE TRAILING UPPER LEVEL
LOW. THE EUROPEAN BRINGS IT DOWN THE NORTHWEST COAST BEFORE OPENING
UP AND MOVING INTO NORTHERN CALIFORNIA MONDAY NIGHT. THE GFS TAKES A
MUCH MORE PROGRESSIVE TACK...OPENING THE LOW UP AND BRINGING IT INTO
BRITISH COLUMBIA SATURDAY AFTERNOON. THE CURRENT FORECAST CONTINUES
TO REFLECT A COOL AND UNSETTLED PATTERN THROUGH THE WEEKEND.

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&


.AVIATION...A BROAD LOW AMPLITUDE UPPER LEVEL RIDGE CENTERED OVER ID
AT 15Z WILL MOVE OVER W MT BY 00Z. A COLD FRONT ALONG 130W AT 15Z
WILL APPROACH THE COAST THIS AFTERNOON...REACHING THE N COAST AROUND
03Z AND CROSSING PUGET SOUND AROUND 06Z. SW FLOW ALOFT WILL INCREASE
AS THE FRONT APPROACHES.

THE AIR MASS OVER W WA IS SOMEWHAT MOIST AND STABLE WITH CIGS MAINLY
SCT-BKN050-070 WITH HIGHER LAYERS. PATCHY MVFR/IFR CIGS MAINLY OVER
S PUGET SOUND AND THE SW INTERIOR SHOULD DISSIPATE BY 18Z.

CIGS ARE EXPECTED TO LOWER TO MVFR LEVELS TONIGHT AS THE COLD FRONT
MOVES ACROSS THE AREA. ONSHORE FLOW BEHIND THE FRONT WILL KEEP CIGS
MVFR WITH LOCAL IFR POSSIBLE TUESDAY MORNING. S WINDS THROUGH THE
INTERIOR WILL BECOME GUSTY BY THIS AFTERNOON AS THE FRONT APPROACHES.

KSEA...VFR CONDITIONS WILL CONTINUE THROUGH 03Z WITH CLOUD LAYERS
SCT-BKN060 AND HIGHER. CIGS ARE EXPECTED TO LOWER TO MVFR AS THE
COLD FRONT APPROACHES...THEN CROSSES PUGET SOUND AROUND 06Z. SURFACE
WINDS WILL BE S-SW 6-12 KT. KAM

&&

.MARINE...A SMALL SURFACE RIDGE WILL REMAIN OVER W WA TODAY...WHILE
AN OFFSHORE COLD FRONT APPROACHES THE COAST. THE COLD FRONT WILL
REACH THE N COAST THIS EVENING AROUND 8 PM THEN CROSS PUGET SOUND
BEFORE MIDNIGHT. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR S WINDS
AHEAD OF THE FRONT FOR BOTH THE COAST AND INLAND WATERS. THE LATEST
MESOSCALE MODELS HAVE BACKED OFF SLIGHTLY ON THE S WINDS THROUGH THE
INLAND WATERS TODAY WITH POCKETS OF WINDS PEAKING CLOSE TO 20 KT.

STRONG WESTERLY ONSHORE FLOW WILL DEVELOP IN THE STRAIT IMMEDIATELY
BEHIND THE FRONT TONIGHT. A GALE WARNING IS IN EFFECT. THERE REMAINS
A DIFFERENCE BETWEEN THE MODELS REGARDING WIND SPEEDS. THE GFS40
UIL-BLI PRESSURE GRADIENT REACHES BETWEEN 4 AND 5 MB WHICH WOULD BE
ENOUGH FOR GALE FORCE WINDS. HOWEVER ALL THE MESOSCALE MODELS
INCLUDING THE 06Z CANADIAN LAM TOP THE WINDS AT 30 KT FOR A HIGH END
SCA.

WEAKER ONSHORE FLOW WILL PREVAIL WEDNESDAY AND THURSDAY AS A RIDGE
BUILDS OFFSHORE. THERE SHOULD BE ENOUGH W PRESSURE GRADIENT THROUGH
THE STRAIT FOR SCA WINDS IN THE EVENINGS. ANOTHER COLD FRONT WILL
PROBABLY REACH THE AREA FRIDAY.

THERE WILL BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS THROUGH TUESDAY. BAR CONDITIONS WILL BE ROUGH AS WELL.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COASTAL WATERS...ENTRANCES TO THE
       STRAIT...ADMIRALTY INLET...NORTHERN INLAND WATERS...PUGET
       SOUND AND HOOD CANAL.
     GALE WARNING CENTRAL STRAIT OF JUAN DE FUCA AND EAST ENTRANCE
       STRAIT THIS EVENING THROUGH TUESDAY AFTERNOON.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.

&&

$$

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






000
FXUS66 KSEW 301602
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
902 AM PDT MON MAR 30 2015

.SYNOPSIS...WARM AIR ADVECTION WILL KEEP RAIN AT TIMES OVER THE
COAST AND NORTHERN INTERIOR TODAY. A COLD FRONT WILL SPREAD RAIN
ACROSS THE AREA TONIGHT FOLLOWED BY AN UPPER LEVEL TROUGH TUESDAY
FOR SHOWERS AND COOLER WEATHER. SHOWERS WILL DIMINISH THURSDAY AS
WEAK RIDGING BUILDS OVER THE AREA AHEAD OF A FRONTAL SYSTEM THAT
WILL AFFECT THE AREA ON FRIDAY.

&&

.SHORT TERM...A WARM FRONT OVER SOUTHERN B.C. IS CLIPPING WESTERN WA
THIS MORNING WITH A FEW LIGHT SHOWERS ALONG THE COAST AND NEAR THE
CANADIAN BORDER. THE INTERIOR WILL REMAIN DRY AND MOSTLY CLOUDY. THE
AIR MASS IS PRETTY MILD AND WE WILL SEE TEMPS IN THE LOW TO MID 60S
TODAY. THE CURRENT FORECAST IS ON TRACK.

THE COLD FRONT WILL SLIDE S/SE TONIGHT FOR A PERIOD OF WETTER
WEATHER ACROSS WESTERN WA. RAIN WILL MAINLY AFFECT THE COAST THIS
EVENING...WITH RAIN IN THE INTERIOR AFTER MIDNIGHT TONIGHT. THE
UPPER LEVEL TROUGH AND ONSHORE FLOW WILL MAINTAIN COOL AND SHOWERY
WEATHER THROUGH TUESDAY. SNOW LEVELS WILL DROP TO AROUND 3000 FT
WITH A FEW INCHES OF SNOW IN THE MOUNTAINS. A PUGET SOUND
CONVERGENCE ZONE MAY ENHANCE AMOUNTS. MODELS ALSO SHOW A NEGATIVE
LIFTED INDEX AND CANNOT RULE OUT ISOLATED THUNDERSTORMS TUE
AFTERNOON. HIGHS ON TUE WILL BE IN THE LOW TO MID 50S - A FEW
DEGREES BELOW NORMAL.

THE AIR MASS WILL REMAIN COOL AND UNSTABLE AS WE HEAD INTO WEDNESDAY
WITH A TROUGH STILL OVERHEAD. LOW LEVEL ONSHORE FLOW WILL PREVAIL
FOR SCATTERED SHOWERS. 33

.LONG TERM...PREVIOUS DISCUSSION...MEDIUM RANGE MODELS CONTINUE TO
SHOW UPPER LEVEL RIDGING ON THURSDAY AS A DEEP UPPER LEVEL LOW MOVES
INTO THE GULF OF ALASKA. THE BRIEF RIDGING ON THURSDAY WILL LIKELY
GIVE THE A BREAK IN THE SHOWERS BEFORE A FRONT ARRIVES FRIDAY. BOTH
THE GFS AND ECMWF DIFFER ON THE TRACK OF THE TRAILING UPPER LEVEL
LOW. THE EUROPEAN BRINGS IT DOWN THE NORTHWEST COAST BEFORE OPENING
UP AND MOVING INTO NORTHERN CALIFORNIA MONDAY NIGHT. THE GFS TAKES A
MUCH MORE PROGRESSIVE TACK...OPENING THE LOW UP AND BRINGING IT INTO
BRITISH COLUMBIA SATURDAY AFTERNOON. THE CURRENT FORECAST CONTINUES
TO REFLECT A COOL AND UNSETTLED PATTERN THROUGH THE WEEKEND.

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&


.AVIATION...A BROAD LOW AMPLITUDE UPPER LEVEL RIDGE CENTERED OVER ID
AT 15Z WILL MOVE OVER W MT BY 00Z. A COLD FRONT ALONG 130W AT 15Z
WILL APPROACH THE COAST THIS AFTERNOON...REACHING THE N COAST AROUND
03Z AND CROSSING PUGET SOUND AROUND 06Z. SW FLOW ALOFT WILL INCREASE
AS THE FRONT APPROACHES.

THE AIR MASS OVER W WA IS SOMEWHAT MOIST AND STABLE WITH CIGS MAINLY
SCT-BKN050-070 WITH HIGHER LAYERS. PATCHY MVFR/IFR CIGS MAINLY OVER
S PUGET SOUND AND THE SW INTERIOR SHOULD DISSIPATE BY 18Z.

CIGS ARE EXPECTED TO LOWER TO MVFR LEVELS TONIGHT AS THE COLD FRONT
MOVES ACROSS THE AREA. ONSHORE FLOW BEHIND THE FRONT WILL KEEP CIGS
MVFR WITH LOCAL IFR POSSIBLE TUESDAY MORNING. S WINDS THROUGH THE
INTERIOR WILL BECOME GUSTY BY THIS AFTERNOON AS THE FRONT APPROACHES.

KSEA...VFR CONDITIONS WILL CONTINUE THROUGH 03Z WITH CLOUD LAYERS
SCT-BKN060 AND HIGHER. CIGS ARE EXPECTED TO LOWER TO MVFR AS THE
COLD FRONT APPROACHES...THEN CROSSES PUGET SOUND AROUND 06Z. SURFACE
WINDS WILL BE S-SW 6-12 KT. KAM

&&

.MARINE...A SMALL SURFACE RIDGE WILL REMAIN OVER W WA TODAY...WHILE
AN OFFSHORE COLD FRONT APPROACHES THE COAST. THE COLD FRONT WILL
REACH THE N COAST THIS EVENING AROUND 8 PM THEN CROSS PUGET SOUND
BEFORE MIDNIGHT. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR S WINDS
AHEAD OF THE FRONT FOR BOTH THE COAST AND INLAND WATERS. THE LATEST
MESOSCALE MODELS HAVE BACKED OFF SLIGHTLY ON THE S WINDS THROUGH THE
INLAND WATERS TODAY WITH POCKETS OF WINDS PEAKING CLOSE TO 20 KT.

STRONG WESTERLY ONSHORE FLOW WILL DEVELOP IN THE STRAIT IMMEDIATELY
BEHIND THE FRONT TONIGHT. A GALE WARNING IS IN EFFECT. THERE REMAINS
A DIFFERENCE BETWEEN THE MODELS REGARDING WIND SPEEDS. THE GFS40
UIL-BLI PRESSURE GRADIENT REACHES BETWEEN 4 AND 5 MB WHICH WOULD BE
ENOUGH FOR GALE FORCE WINDS. HOWEVER ALL THE MESOSCALE MODELS
INCLUDING THE 06Z CANADIAN LAM TOP THE WINDS AT 30 KT FOR A HIGH END
SCA.

WEAKER ONSHORE FLOW WILL PREVAIL WEDNESDAY AND THURSDAY AS A RIDGE
BUILDS OFFSHORE. THERE SHOULD BE ENOUGH W PRESSURE GRADIENT THROUGH
THE STRAIT FOR SCA WINDS IN THE EVENINGS. ANOTHER COLD FRONT WILL
PROBABLY REACH THE AREA FRIDAY.

THERE WILL BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS THROUGH TUESDAY. BAR CONDITIONS WILL BE ROUGH AS WELL.

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COASTAL WATERS...ENTRANCES TO THE
       STRAIT...ADMIRALTY INLET...NORTHERN INLAND WATERS...PUGET
       SOUND AND HOOD CANAL.
     GALE WARNING CENTRAL STRAIT OF JUAN DE FUCA AND EAST ENTRANCE
       STRAIT THIS EVENING THROUGH TUESDAY AFTERNOON.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.

&&

$$

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







000
FXUS66 KSEW 301037
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
340 AM PDT MON MAR 30 2015

.SYNOPSIS...WARM AIR ADVECTION WILL KEEP RAIN AT TIMES OVER THE
COAST AND NORTHERN INTERIOR TODAY. A COLD FRONT WILL SPREAD RAIN
ACROSS THE AREA TONIGHT FOLLOWED BY AN UPPER LEVEL TROUGH TUESDAY
FOR SHOWERS AND COOLER WEATHER. SHOWERS WILL DIMINISH THURSDAY AS
WEAK RIDGING BUILDS OVER THE AREA AHEAD OF A FRONTAL SYSTEM THAT
WILL AFFECT THE AREA ON FRIDAY.

&&

.SHORT TERM...THE WARM FRONT THAT HAS BROUGHT RAIN AT TIMES TO THE
COAST AND NORTHERN INTERIOR OVER THE LAST DAY WILL SHIFT INTO
BRITISH COLUMBIA TODAY AS A COLD FRONT APPROACHES FROM THE WEST.
EXPECT ONE MORE DAY OF RELATIVELY MILD TEMPERATURES TODAY. EVENING
MODEL RUNS WERE A BIT SLOWER WITH THE FRONTAL PASSAGE TONIGHT...BUT
SILL SPREAD RAIN THROUGH INTO THE INTERIOR LATE IN THE EVENING AND
INTO THE CASCADES BY EARLY TUESDAY MORNING. EXPECT BREEZY CONDITIONS
TONIGHT AS THE FRONT WORKS THROUGH THE INTERIOR...FOLLOWED BY
SHOWERS AND BREEZY CONDITIONS AGAIN TUESDAY BEHIND THE FRONT.
HEIGHTS ON TUESDAY WILL FALL SIGNIFICANTLY WITH HIGH TEMPERATURES
PEAKING IN THE LOW TO MID 50S AND SNOW LEVELS DROPPING TO AROUND
3000 FT. MESOSCALE MODELS CONTINUE TO ADVERTISE THE DEVELOPMENT OF A
PUGET SOUND CONVERGENCE ZONE IN THE POST FRONTAL WESTERLY FLOW
TUESDAY AND TUESDAY EVENING. IN ADDITION...THE CURRENT FORECAST
PACKAGE CONTINUES TO HIGHLIGHT A CHANCE OF THUNDERSTORMS OVER MUCH
OF THE AREA TUESDAY AFTERNOON AS THE COOLER AIR ALOFT MOVES OVER
WESTERN WASHINGTON. LOWER SNOW LEVELS AND ENHANCED PRECIPITATION
ASSOCIATED WITH A PUGET SOUND CONVERGENCE ZONE OVER THE CASCADES OF
SNOHOMISH AND KING COUNTIES MAY EQUATE TO ADVISORY LEVEL
ACCUMULATIONS THROUGH TUESDAY EVENING.

SHOWERS WILL GENERALLY DIMINISH WEDNESDAY AS THE UPPER LEVEL TROUGH
SHIFTS INTO THE NORTHERN INTERMOUNTAIN AREA. MODELS CONTINUE TO SHOW
A SHORTWAVE TROUGH DIGGING INTO OREGON LATE WEDNESDAY AFTERNOON OR
EVENING THAT WILL LIKELY BOOST SHOWERS. HIGH TEMPERATURES WILL
REMAIN IN THE LOW 50S WEDNESDAY.

.LONG TERM...MEDIUM RANGE MODELS CONTINUE TO SHOW UPPER LEVEL
RIDGING ON THURSDAY AS A DEEP UPPER LEVEL LOW MOVES INTO THE GULF OF
ALASKA. THE BRIEF RIDGING ON THURSDAY WILL LIKELY GIVE THE A BREAK
IN THE SHOWERS BEFORE A FRONT ARRIVES FRIDAY. BOTH THE GFS AND ECMWF
DIFFER ON THE TRACK OF THE TRAILING UPPER LEVEL LOW. THE EUROPEAN
BRINGS IT DOWN THE NORTHWEST COAST BEFORE OPENING UP AND MOVING INTO
NORTHERN CALIFORNIA MONDAY NIGHT. THE GFS TAKES A MUCH MORE
PROGRESSIVE TACK...OPENING THE LOW UP AND BRINGING IT INTO BRITISH
COLUMBIA SATURDAY AFTERNOON. THE CURRENT FORECAST CONTINUES TO
REFLECT A COOL AND UNSETTLED PATTERN THROUGH THE WEEKEND.

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A FLAT UPPER RIDGE OVER THE REGION THIS MORNING WILL
MOVE EAST...WHILE A COLD FRONT MOVES INTO THE COASTAL WATERS TODAY
AND ACROSS WESTERN WASHINGTON TONIGHT. THE FLOW ALOFT WILL BE
SOUTHWEST. THE AIR MASS WILL BE MOIST BELOW 10000 FT...AND IT WILL
BECOME WEAKLY UNSTABLE TONIGHT.

MOSTLY VFR CONDITIONS ACROSS THE FORECAST AREA EARLY THIS MORNING
WITH SCT030 OVC060-080 AND AREAS OF LIGHT RAIN -- MAINLY ALONG THE
COAST AND IN THE NORTH INTERIOR. ON THE WHOLE THERE WILL NOT BE MUCH
CHANGE TODAY. CONDITIONS WILL DETERIORATE TO MVFR AND LOCAL IFR LATE
TONIGHT AS A COLD FRONT MOVES ACROSS THE AREA.

KSEA...SOUTH WIND 6-12 KT TODAY...BECOMING SOUTHWEST 12-16 KT
GUSTING 24 KT THIS EVENING.   MCDONNAL

&&

.MARINE...A RIDGE OVER WESTERN WASHINGTON WILL WEAKEN THIS MORNING
AS A COLD FRONT MOVES INTO THE COASTAL WATERS. THE FRONT WILL MOVE
INLAND THIS EVENING...FOLLOWED BY STRONG ONSHORE FLOW LATER TONIGHT
AND TUESDAY. SMALL CRAFT ADVISORY CONDITIONS WILL PREVAIL THROUGH
THIS PERIOD. THE STRENGTH OF THE ONSHORE FLOW MAKES WESTERLY GALES
IN THE CENTRAL AND EASTERN STRAIT OF JUAN DE FUCA APPEAR LIKELY LATE
THIS EVENING INTO TUESDAY...AND CONFIDENCE IS HIGH ENOUGH TO UPGRADE
THE GALE WATCH TO A WARNING. PSPC VANCOUVER HAS A GALE WARNING IN
EFFECT AS WELL.

THERE WILL BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS THROUGH TUESDAY. BAR CONDITIONS WILL BE ROUGH AS WELL.

ONSHORE FLOW WILL WEAKEN WEDNESDAY AND THURSDAY AS A RIDGE BUILDS
OVER THE REGION. A RELATIVELY WEAK FRONT WILL PROBABLY REACH THE
AREA FRIDAY.   MCDONNAL

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COASTAL WATERS...ENTRANCES TO THE
       STRAIT...ADMIRALTY INLET...NORTHERN INLAND WATERS...PUGET
       SOUND AND HOOD CANAL.
     GALE WARNING CENTRAL STRAIT OF JUAN DE FUCA AND EAST ENTRANCE
       STRAIT THIS EVENING THROUGH TUESDAY AFTERNOON.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.

&&

$$

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











000
FXUS66 KSEW 301037
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
340 AM PDT MON MAR 30 2015

.SYNOPSIS...WARM AIR ADVECTION WILL KEEP RAIN AT TIMES OVER THE
COAST AND NORTHERN INTERIOR TODAY. A COLD FRONT WILL SPREAD RAIN
ACROSS THE AREA TONIGHT FOLLOWED BY AN UPPER LEVEL TROUGH TUESDAY
FOR SHOWERS AND COOLER WEATHER. SHOWERS WILL DIMINISH THURSDAY AS
WEAK RIDGING BUILDS OVER THE AREA AHEAD OF A FRONTAL SYSTEM THAT
WILL AFFECT THE AREA ON FRIDAY.

&&

.SHORT TERM...THE WARM FRONT THAT HAS BROUGHT RAIN AT TIMES TO THE
COAST AND NORTHERN INTERIOR OVER THE LAST DAY WILL SHIFT INTO
BRITISH COLUMBIA TODAY AS A COLD FRONT APPROACHES FROM THE WEST.
EXPECT ONE MORE DAY OF RELATIVELY MILD TEMPERATURES TODAY. EVENING
MODEL RUNS WERE A BIT SLOWER WITH THE FRONTAL PASSAGE TONIGHT...BUT
SILL SPREAD RAIN THROUGH INTO THE INTERIOR LATE IN THE EVENING AND
INTO THE CASCADES BY EARLY TUESDAY MORNING. EXPECT BREEZY CONDITIONS
TONIGHT AS THE FRONT WORKS THROUGH THE INTERIOR...FOLLOWED BY
SHOWERS AND BREEZY CONDITIONS AGAIN TUESDAY BEHIND THE FRONT.
HEIGHTS ON TUESDAY WILL FALL SIGNIFICANTLY WITH HIGH TEMPERATURES
PEAKING IN THE LOW TO MID 50S AND SNOW LEVELS DROPPING TO AROUND
3000 FT. MESOSCALE MODELS CONTINUE TO ADVERTISE THE DEVELOPMENT OF A
PUGET SOUND CONVERGENCE ZONE IN THE POST FRONTAL WESTERLY FLOW
TUESDAY AND TUESDAY EVENING. IN ADDITION...THE CURRENT FORECAST
PACKAGE CONTINUES TO HIGHLIGHT A CHANCE OF THUNDERSTORMS OVER MUCH
OF THE AREA TUESDAY AFTERNOON AS THE COOLER AIR ALOFT MOVES OVER
WESTERN WASHINGTON. LOWER SNOW LEVELS AND ENHANCED PRECIPITATION
ASSOCIATED WITH A PUGET SOUND CONVERGENCE ZONE OVER THE CASCADES OF
SNOHOMISH AND KING COUNTIES MAY EQUATE TO ADVISORY LEVEL
ACCUMULATIONS THROUGH TUESDAY EVENING.

SHOWERS WILL GENERALLY DIMINISH WEDNESDAY AS THE UPPER LEVEL TROUGH
SHIFTS INTO THE NORTHERN INTERMOUNTAIN AREA. MODELS CONTINUE TO SHOW
A SHORTWAVE TROUGH DIGGING INTO OREGON LATE WEDNESDAY AFTERNOON OR
EVENING THAT WILL LIKELY BOOST SHOWERS. HIGH TEMPERATURES WILL
REMAIN IN THE LOW 50S WEDNESDAY.

.LONG TERM...MEDIUM RANGE MODELS CONTINUE TO SHOW UPPER LEVEL
RIDGING ON THURSDAY AS A DEEP UPPER LEVEL LOW MOVES INTO THE GULF OF
ALASKA. THE BRIEF RIDGING ON THURSDAY WILL LIKELY GIVE THE A BREAK
IN THE SHOWERS BEFORE A FRONT ARRIVES FRIDAY. BOTH THE GFS AND ECMWF
DIFFER ON THE TRACK OF THE TRAILING UPPER LEVEL LOW. THE EUROPEAN
BRINGS IT DOWN THE NORTHWEST COAST BEFORE OPENING UP AND MOVING INTO
NORTHERN CALIFORNIA MONDAY NIGHT. THE GFS TAKES A MUCH MORE
PROGRESSIVE TACK...OPENING THE LOW UP AND BRINGING IT INTO BRITISH
COLUMBIA SATURDAY AFTERNOON. THE CURRENT FORECAST CONTINUES TO
REFLECT A COOL AND UNSETTLED PATTERN THROUGH THE WEEKEND.

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A FLAT UPPER RIDGE OVER THE REGION THIS MORNING WILL
MOVE EAST...WHILE A COLD FRONT MOVES INTO THE COASTAL WATERS TODAY
AND ACROSS WESTERN WASHINGTON TONIGHT. THE FLOW ALOFT WILL BE
SOUTHWEST. THE AIR MASS WILL BE MOIST BELOW 10000 FT...AND IT WILL
BECOME WEAKLY UNSTABLE TONIGHT.

MOSTLY VFR CONDITIONS ACROSS THE FORECAST AREA EARLY THIS MORNING
WITH SCT030 OVC060-080 AND AREAS OF LIGHT RAIN -- MAINLY ALONG THE
COAST AND IN THE NORTH INTERIOR. ON THE WHOLE THERE WILL NOT BE MUCH
CHANGE TODAY. CONDITIONS WILL DETERIORATE TO MVFR AND LOCAL IFR LATE
TONIGHT AS A COLD FRONT MOVES ACROSS THE AREA.

KSEA...SOUTH WIND 6-12 KT TODAY...BECOMING SOUTHWEST 12-16 KT
GUSTING 24 KT THIS EVENING.   MCDONNAL

&&

.MARINE...A RIDGE OVER WESTERN WASHINGTON WILL WEAKEN THIS MORNING
AS A COLD FRONT MOVES INTO THE COASTAL WATERS. THE FRONT WILL MOVE
INLAND THIS EVENING...FOLLOWED BY STRONG ONSHORE FLOW LATER TONIGHT
AND TUESDAY. SMALL CRAFT ADVISORY CONDITIONS WILL PREVAIL THROUGH
THIS PERIOD. THE STRENGTH OF THE ONSHORE FLOW MAKES WESTERLY GALES
IN THE CENTRAL AND EASTERN STRAIT OF JUAN DE FUCA APPEAR LIKELY LATE
THIS EVENING INTO TUESDAY...AND CONFIDENCE IS HIGH ENOUGH TO UPGRADE
THE GALE WATCH TO A WARNING. PSPC VANCOUVER HAS A GALE WARNING IN
EFFECT AS WELL.

THERE WILL BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS THROUGH TUESDAY. BAR CONDITIONS WILL BE ROUGH AS WELL.

ONSHORE FLOW WILL WEAKEN WEDNESDAY AND THURSDAY AS A RIDGE BUILDS
OVER THE REGION. A RELATIVELY WEAK FRONT WILL PROBABLY REACH THE
AREA FRIDAY.   MCDONNAL

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COASTAL WATERS...ENTRANCES TO THE
       STRAIT...ADMIRALTY INLET...NORTHERN INLAND WATERS...PUGET
       SOUND AND HOOD CANAL.
     GALE WARNING CENTRAL STRAIT OF JUAN DE FUCA AND EAST ENTRANCE
       STRAIT THIS EVENING THROUGH TUESDAY AFTERNOON.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.

&&

$$

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











000
FXUS66 KSEW 301037
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
340 AM PDT MON MAR 30 2015

.SYNOPSIS...WARM AIR ADVECTION WILL KEEP RAIN AT TIMES OVER THE
COAST AND NORTHERN INTERIOR TODAY. A COLD FRONT WILL SPREAD RAIN
ACROSS THE AREA TONIGHT FOLLOWED BY AN UPPER LEVEL TROUGH TUESDAY
FOR SHOWERS AND COOLER WEATHER. SHOWERS WILL DIMINISH THURSDAY AS
WEAK RIDGING BUILDS OVER THE AREA AHEAD OF A FRONTAL SYSTEM THAT
WILL AFFECT THE AREA ON FRIDAY.

&&

.SHORT TERM...THE WARM FRONT THAT HAS BROUGHT RAIN AT TIMES TO THE
COAST AND NORTHERN INTERIOR OVER THE LAST DAY WILL SHIFT INTO
BRITISH COLUMBIA TODAY AS A COLD FRONT APPROACHES FROM THE WEST.
EXPECT ONE MORE DAY OF RELATIVELY MILD TEMPERATURES TODAY. EVENING
MODEL RUNS WERE A BIT SLOWER WITH THE FRONTAL PASSAGE TONIGHT...BUT
SILL SPREAD RAIN THROUGH INTO THE INTERIOR LATE IN THE EVENING AND
INTO THE CASCADES BY EARLY TUESDAY MORNING. EXPECT BREEZY CONDITIONS
TONIGHT AS THE FRONT WORKS THROUGH THE INTERIOR...FOLLOWED BY
SHOWERS AND BREEZY CONDITIONS AGAIN TUESDAY BEHIND THE FRONT.
HEIGHTS ON TUESDAY WILL FALL SIGNIFICANTLY WITH HIGH TEMPERATURES
PEAKING IN THE LOW TO MID 50S AND SNOW LEVELS DROPPING TO AROUND
3000 FT. MESOSCALE MODELS CONTINUE TO ADVERTISE THE DEVELOPMENT OF A
PUGET SOUND CONVERGENCE ZONE IN THE POST FRONTAL WESTERLY FLOW
TUESDAY AND TUESDAY EVENING. IN ADDITION...THE CURRENT FORECAST
PACKAGE CONTINUES TO HIGHLIGHT A CHANCE OF THUNDERSTORMS OVER MUCH
OF THE AREA TUESDAY AFTERNOON AS THE COOLER AIR ALOFT MOVES OVER
WESTERN WASHINGTON. LOWER SNOW LEVELS AND ENHANCED PRECIPITATION
ASSOCIATED WITH A PUGET SOUND CONVERGENCE ZONE OVER THE CASCADES OF
SNOHOMISH AND KING COUNTIES MAY EQUATE TO ADVISORY LEVEL
ACCUMULATIONS THROUGH TUESDAY EVENING.

SHOWERS WILL GENERALLY DIMINISH WEDNESDAY AS THE UPPER LEVEL TROUGH
SHIFTS INTO THE NORTHERN INTERMOUNTAIN AREA. MODELS CONTINUE TO SHOW
A SHORTWAVE TROUGH DIGGING INTO OREGON LATE WEDNESDAY AFTERNOON OR
EVENING THAT WILL LIKELY BOOST SHOWERS. HIGH TEMPERATURES WILL
REMAIN IN THE LOW 50S WEDNESDAY.

.LONG TERM...MEDIUM RANGE MODELS CONTINUE TO SHOW UPPER LEVEL
RIDGING ON THURSDAY AS A DEEP UPPER LEVEL LOW MOVES INTO THE GULF OF
ALASKA. THE BRIEF RIDGING ON THURSDAY WILL LIKELY GIVE THE A BREAK
IN THE SHOWERS BEFORE A FRONT ARRIVES FRIDAY. BOTH THE GFS AND ECMWF
DIFFER ON THE TRACK OF THE TRAILING UPPER LEVEL LOW. THE EUROPEAN
BRINGS IT DOWN THE NORTHWEST COAST BEFORE OPENING UP AND MOVING INTO
NORTHERN CALIFORNIA MONDAY NIGHT. THE GFS TAKES A MUCH MORE
PROGRESSIVE TACK...OPENING THE LOW UP AND BRINGING IT INTO BRITISH
COLUMBIA SATURDAY AFTERNOON. THE CURRENT FORECAST CONTINUES TO
REFLECT A COOL AND UNSETTLED PATTERN THROUGH THE WEEKEND.

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A FLAT UPPER RIDGE OVER THE REGION THIS MORNING WILL
MOVE EAST...WHILE A COLD FRONT MOVES INTO THE COASTAL WATERS TODAY
AND ACROSS WESTERN WASHINGTON TONIGHT. THE FLOW ALOFT WILL BE
SOUTHWEST. THE AIR MASS WILL BE MOIST BELOW 10000 FT...AND IT WILL
BECOME WEAKLY UNSTABLE TONIGHT.

MOSTLY VFR CONDITIONS ACROSS THE FORECAST AREA EARLY THIS MORNING
WITH SCT030 OVC060-080 AND AREAS OF LIGHT RAIN -- MAINLY ALONG THE
COAST AND IN THE NORTH INTERIOR. ON THE WHOLE THERE WILL NOT BE MUCH
CHANGE TODAY. CONDITIONS WILL DETERIORATE TO MVFR AND LOCAL IFR LATE
TONIGHT AS A COLD FRONT MOVES ACROSS THE AREA.

KSEA...SOUTH WIND 6-12 KT TODAY...BECOMING SOUTHWEST 12-16 KT
GUSTING 24 KT THIS EVENING.   MCDONNAL

&&

.MARINE...A RIDGE OVER WESTERN WASHINGTON WILL WEAKEN THIS MORNING
AS A COLD FRONT MOVES INTO THE COASTAL WATERS. THE FRONT WILL MOVE
INLAND THIS EVENING...FOLLOWED BY STRONG ONSHORE FLOW LATER TONIGHT
AND TUESDAY. SMALL CRAFT ADVISORY CONDITIONS WILL PREVAIL THROUGH
THIS PERIOD. THE STRENGTH OF THE ONSHORE FLOW MAKES WESTERLY GALES
IN THE CENTRAL AND EASTERN STRAIT OF JUAN DE FUCA APPEAR LIKELY LATE
THIS EVENING INTO TUESDAY...AND CONFIDENCE IS HIGH ENOUGH TO UPGRADE
THE GALE WATCH TO A WARNING. PSPC VANCOUVER HAS A GALE WARNING IN
EFFECT AS WELL.

THERE WILL BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS THROUGH TUESDAY. BAR CONDITIONS WILL BE ROUGH AS WELL.

ONSHORE FLOW WILL WEAKEN WEDNESDAY AND THURSDAY AS A RIDGE BUILDS
OVER THE REGION. A RELATIVELY WEAK FRONT WILL PROBABLY REACH THE
AREA FRIDAY.   MCDONNAL

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COASTAL WATERS...ENTRANCES TO THE
       STRAIT...ADMIRALTY INLET...NORTHERN INLAND WATERS...PUGET
       SOUND AND HOOD CANAL.
     GALE WARNING CENTRAL STRAIT OF JUAN DE FUCA AND EAST ENTRANCE
       STRAIT THIS EVENING THROUGH TUESDAY AFTERNOON.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.

&&

$$

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












000
FXUS66 KSEW 300354
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PDT SUN MAR 29 2015

.SYNOPSIS...A STATIONARY FRONT WILL BRING RAIN AT TIMES TO NORTHERN
AND COASTAL SECTIONS THROUGH MONDAY. A COLD FRONT WILL SPREAD RAIN
ACROSS THE AREA MONDAY NIGHT. AN UPPER LEVEL TROUGH WILL SETTLE OVER
THE PACIFIC NORTHWEST TUESDAY AND WEDNESDAY PROVIDING COOL SHOWERY
WEATHER. SHOWERS WILL DECREASE THURSDAY...THEN RAIN DEVELOPS FRIDAY
AS THE NEXT TROUGH MOVES OVER THE REGION.

&&

.SHORT TERM...THE STATIONARY FRONT THAT HAS BROUGHT RAIN AT TIMES TO
THE COAST AND NORTHERN INTERIOR FOR THE LAST 24 HOURS OR SO WILL
CONTINUE TO DO SO FOR ANOTHER 24. TOMORROW WILL BE ONE LAST DAY IN
THE WARM SECTOR AND HIGH TEMPERATURES ARE FORECAST TO BE IN THE 60S.
A COLD FRONT WILL FINALLY MOVE THROUGH MONDAY NIGHT...SPREADING RAIN
OVER THE WHOLE AREA.

SHOWERS AND BREEZY CONDITIONS WILL FOLLOW ON TUESDAY. HEIGHTS WILL
FALL SIGNIFICANTLY WITH HIGH TEMPERATURES ONLY REACHING THE LOW TO
MID 50S. THE SNOW LEVEL WILL FALL TO AS LOW AS 3000 FEET. THIS MEANS
THERE WILL BE SNOW IN THE PASSES AND ALSO IN A PUGET SOUND
CONVERGENCE ZONE IN THE MOUNTAINS. A SNOW ADVISORY COULD BE NEEDED.

SHOWERS TAPER WEDNESDAY. A LITTLE WARMING IS LIKELY. BURKE

.LONG TERM...PREVIOUS DISCUSSION...THE GFS/ECMWF ARE COMING INTO
BETTER AGREEMENT SHOWING A SHORT WAVE RIDGE ON THURSDAY...THE
ANOTHER TROUGH ARRIVING FRIDAY. THERE COULD STILL BE SOME WEAK
DIURNAL SHOWER ACTIVITY THURSDAY AND THE GFS DOES KEEP SOME SPOTTY
LIGHT QPF AROUND. LEFT A CHANCE OF SHOWERS IN THE FORECAST FOR NOW
BUT POPS MIGHT NEED TO BE PULLED IF MODELS CONTINUE WITH THE RIDGE
SOLUTION.

A FRONT BRINGS RAIN INTO WESTERN WASHINGTON ON FRIDAY...THEN A
TROUGH MOVES INTO THE REGION OVER THE WEEKEND. IT WILL BE COOL AND
UNSETTLED WITH SHOWERS ACROSS THE AREA. SNOW LEVELS WILL BE LOW AT
AROUND 3000 FEET BUT THE SHOWERY PATTERN IS PROBABLY NOT CONDUCIVE
FOR MUCH SNOW ACCUMULATION. MERCER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A BROAD FLAT UPPER RIDGE WILL REMAIN OVER THE REGION
TONIGHT...THEN WEAKEN AND MOVE EAST MONDAY AS A COLD FRONT MOVES
INTO THE COASTAL WATERS. WESTERLY FLOW ALOFT TONIGHT WILL BACK TO
SOUTHWEST MONDAY. THE AIR MASS WILL BE GENERALLY STABLE AND MOIST
BELOW 10000 FT.

MOSTLY VFR CONDITIONS ACROSS THE FORECAST AREA THIS EVENING WITH
SCT030-040 BKN050-070 OVC090-120. THERE ARE AREAS -- MAINLY ALONG
THE COAST AND IN THE NORTH INTERIOR -- OF OVC023-030 WITH -RA. ON
THE WHOLE THERE WILL NOT BE MUCH CHANGE THROUGH MONDAY.

KSEA...SOUTH WIND 5-10 KT.   MCDONNAL

&&

.MARINE...A RIDGE OVER WESTERN WASHINGTON WILL WEAKEN EARLY MONDAY
AS A COLD FRONT MOVES INTO THE COASTAL WATERS. THE FRONT WILL MOVE
INLAND MONDAY EVENING...FOLLOWED BY STRONG ONSHORE FLOW MONDAY NIGHT
AND TUESDAY. SMALL CRAFT ADVISORY CONDITIONS WILL PREVAIL FOR MOST
OF THE MARINE ZONES THROUGH THIS PERIOD...AND WESTERLY GALES ARE
POSSIBLE IN THE CENTRAL AND EASTERN STRAIT OF JUAN DE FUCA LATER
MONDAY NIGHT AND TUESDAY.

ONSHORE FLOW WILL WEAKEN WEDNESDAY AND THURSDAY AS A RIDGE BUILDS
OVER THE REGION. A RELATIVELY WEAK FRONT WILL PROBABLY REACH THE
AREA FRIDAY.   MCDONNAL

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.
     GALE WATCH FOR MONDAY NIGHT AND TUESDAY CENTRAL STRAIT AND
       EAST ENTRANCE STRAIT.

&&

$$

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








000
FXUS66 KSEW 300354
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PDT SUN MAR 29 2015

.SYNOPSIS...A STATIONARY FRONT WILL BRING RAIN AT TIMES TO NORTHERN
AND COASTAL SECTIONS THROUGH MONDAY. A COLD FRONT WILL SPREAD RAIN
ACROSS THE AREA MONDAY NIGHT. AN UPPER LEVEL TROUGH WILL SETTLE OVER
THE PACIFIC NORTHWEST TUESDAY AND WEDNESDAY PROVIDING COOL SHOWERY
WEATHER. SHOWERS WILL DECREASE THURSDAY...THEN RAIN DEVELOPS FRIDAY
AS THE NEXT TROUGH MOVES OVER THE REGION.

&&

.SHORT TERM...THE STATIONARY FRONT THAT HAS BROUGHT RAIN AT TIMES TO
THE COAST AND NORTHERN INTERIOR FOR THE LAST 24 HOURS OR SO WILL
CONTINUE TO DO SO FOR ANOTHER 24. TOMORROW WILL BE ONE LAST DAY IN
THE WARM SECTOR AND HIGH TEMPERATURES ARE FORECAST TO BE IN THE 60S.
A COLD FRONT WILL FINALLY MOVE THROUGH MONDAY NIGHT...SPREADING RAIN
OVER THE WHOLE AREA.

SHOWERS AND BREEZY CONDITIONS WILL FOLLOW ON TUESDAY. HEIGHTS WILL
FALL SIGNIFICANTLY WITH HIGH TEMPERATURES ONLY REACHING THE LOW TO
MID 50S. THE SNOW LEVEL WILL FALL TO AS LOW AS 3000 FEET. THIS MEANS
THERE WILL BE SNOW IN THE PASSES AND ALSO IN A PUGET SOUND
CONVERGENCE ZONE IN THE MOUNTAINS. A SNOW ADVISORY COULD BE NEEDED.

SHOWERS TAPER WEDNESDAY. A LITTLE WARMING IS LIKELY. BURKE

.LONG TERM...PREVIOUS DISCUSSION...THE GFS/ECMWF ARE COMING INTO
BETTER AGREEMENT SHOWING A SHORT WAVE RIDGE ON THURSDAY...THE
ANOTHER TROUGH ARRIVING FRIDAY. THERE COULD STILL BE SOME WEAK
DIURNAL SHOWER ACTIVITY THURSDAY AND THE GFS DOES KEEP SOME SPOTTY
LIGHT QPF AROUND. LEFT A CHANCE OF SHOWERS IN THE FORECAST FOR NOW
BUT POPS MIGHT NEED TO BE PULLED IF MODELS CONTINUE WITH THE RIDGE
SOLUTION.

A FRONT BRINGS RAIN INTO WESTERN WASHINGTON ON FRIDAY...THEN A
TROUGH MOVES INTO THE REGION OVER THE WEEKEND. IT WILL BE COOL AND
UNSETTLED WITH SHOWERS ACROSS THE AREA. SNOW LEVELS WILL BE LOW AT
AROUND 3000 FEET BUT THE SHOWERY PATTERN IS PROBABLY NOT CONDUCIVE
FOR MUCH SNOW ACCUMULATION. MERCER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A BROAD FLAT UPPER RIDGE WILL REMAIN OVER THE REGION
TONIGHT...THEN WEAKEN AND MOVE EAST MONDAY AS A COLD FRONT MOVES
INTO THE COASTAL WATERS. WESTERLY FLOW ALOFT TONIGHT WILL BACK TO
SOUTHWEST MONDAY. THE AIR MASS WILL BE GENERALLY STABLE AND MOIST
BELOW 10000 FT.

MOSTLY VFR CONDITIONS ACROSS THE FORECAST AREA THIS EVENING WITH
SCT030-040 BKN050-070 OVC090-120. THERE ARE AREAS -- MAINLY ALONG
THE COAST AND IN THE NORTH INTERIOR -- OF OVC023-030 WITH -RA. ON
THE WHOLE THERE WILL NOT BE MUCH CHANGE THROUGH MONDAY.

KSEA...SOUTH WIND 5-10 KT.   MCDONNAL

&&

.MARINE...A RIDGE OVER WESTERN WASHINGTON WILL WEAKEN EARLY MONDAY
AS A COLD FRONT MOVES INTO THE COASTAL WATERS. THE FRONT WILL MOVE
INLAND MONDAY EVENING...FOLLOWED BY STRONG ONSHORE FLOW MONDAY NIGHT
AND TUESDAY. SMALL CRAFT ADVISORY CONDITIONS WILL PREVAIL FOR MOST
OF THE MARINE ZONES THROUGH THIS PERIOD...AND WESTERLY GALES ARE
POSSIBLE IN THE CENTRAL AND EASTERN STRAIT OF JUAN DE FUCA LATER
MONDAY NIGHT AND TUESDAY.

ONSHORE FLOW WILL WEAKEN WEDNESDAY AND THURSDAY AS A RIDGE BUILDS
OVER THE REGION. A RELATIVELY WEAK FRONT WILL PROBABLY REACH THE
AREA FRIDAY.   MCDONNAL

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.
     GALE WATCH FOR MONDAY NIGHT AND TUESDAY CENTRAL STRAIT AND
       EAST ENTRANCE STRAIT.

&&

$$

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








000
FXUS66 KSEW 300354
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PDT SUN MAR 29 2015

.SYNOPSIS...A STATIONARY FRONT WILL BRING RAIN AT TIMES TO NORTHERN
AND COASTAL SECTIONS THROUGH MONDAY. A COLD FRONT WILL SPREAD RAIN
ACROSS THE AREA MONDAY NIGHT. AN UPPER LEVEL TROUGH WILL SETTLE OVER
THE PACIFIC NORTHWEST TUESDAY AND WEDNESDAY PROVIDING COOL SHOWERY
WEATHER. SHOWERS WILL DECREASE THURSDAY...THEN RAIN DEVELOPS FRIDAY
AS THE NEXT TROUGH MOVES OVER THE REGION.

&&

.SHORT TERM...THE STATIONARY FRONT THAT HAS BROUGHT RAIN AT TIMES TO
THE COAST AND NORTHERN INTERIOR FOR THE LAST 24 HOURS OR SO WILL
CONTINUE TO DO SO FOR ANOTHER 24. TOMORROW WILL BE ONE LAST DAY IN
THE WARM SECTOR AND HIGH TEMPERATURES ARE FORECAST TO BE IN THE 60S.
A COLD FRONT WILL FINALLY MOVE THROUGH MONDAY NIGHT...SPREADING RAIN
OVER THE WHOLE AREA.

SHOWERS AND BREEZY CONDITIONS WILL FOLLOW ON TUESDAY. HEIGHTS WILL
FALL SIGNIFICANTLY WITH HIGH TEMPERATURES ONLY REACHING THE LOW TO
MID 50S. THE SNOW LEVEL WILL FALL TO AS LOW AS 3000 FEET. THIS MEANS
THERE WILL BE SNOW IN THE PASSES AND ALSO IN A PUGET SOUND
CONVERGENCE ZONE IN THE MOUNTAINS. A SNOW ADVISORY COULD BE NEEDED.

SHOWERS TAPER WEDNESDAY. A LITTLE WARMING IS LIKELY. BURKE

.LONG TERM...PREVIOUS DISCUSSION...THE GFS/ECMWF ARE COMING INTO
BETTER AGREEMENT SHOWING A SHORT WAVE RIDGE ON THURSDAY...THE
ANOTHER TROUGH ARRIVING FRIDAY. THERE COULD STILL BE SOME WEAK
DIURNAL SHOWER ACTIVITY THURSDAY AND THE GFS DOES KEEP SOME SPOTTY
LIGHT QPF AROUND. LEFT A CHANCE OF SHOWERS IN THE FORECAST FOR NOW
BUT POPS MIGHT NEED TO BE PULLED IF MODELS CONTINUE WITH THE RIDGE
SOLUTION.

A FRONT BRINGS RAIN INTO WESTERN WASHINGTON ON FRIDAY...THEN A
TROUGH MOVES INTO THE REGION OVER THE WEEKEND. IT WILL BE COOL AND
UNSETTLED WITH SHOWERS ACROSS THE AREA. SNOW LEVELS WILL BE LOW AT
AROUND 3000 FEET BUT THE SHOWERY PATTERN IS PROBABLY NOT CONDUCIVE
FOR MUCH SNOW ACCUMULATION. MERCER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A BROAD FLAT UPPER RIDGE WILL REMAIN OVER THE REGION
TONIGHT...THEN WEAKEN AND MOVE EAST MONDAY AS A COLD FRONT MOVES
INTO THE COASTAL WATERS. WESTERLY FLOW ALOFT TONIGHT WILL BACK TO
SOUTHWEST MONDAY. THE AIR MASS WILL BE GENERALLY STABLE AND MOIST
BELOW 10000 FT.

MOSTLY VFR CONDITIONS ACROSS THE FORECAST AREA THIS EVENING WITH
SCT030-040 BKN050-070 OVC090-120. THERE ARE AREAS -- MAINLY ALONG
THE COAST AND IN THE NORTH INTERIOR -- OF OVC023-030 WITH -RA. ON
THE WHOLE THERE WILL NOT BE MUCH CHANGE THROUGH MONDAY.

KSEA...SOUTH WIND 5-10 KT.   MCDONNAL

&&

.MARINE...A RIDGE OVER WESTERN WASHINGTON WILL WEAKEN EARLY MONDAY
AS A COLD FRONT MOVES INTO THE COASTAL WATERS. THE FRONT WILL MOVE
INLAND MONDAY EVENING...FOLLOWED BY STRONG ONSHORE FLOW MONDAY NIGHT
AND TUESDAY. SMALL CRAFT ADVISORY CONDITIONS WILL PREVAIL FOR MOST
OF THE MARINE ZONES THROUGH THIS PERIOD...AND WESTERLY GALES ARE
POSSIBLE IN THE CENTRAL AND EASTERN STRAIT OF JUAN DE FUCA LATER
MONDAY NIGHT AND TUESDAY.

ONSHORE FLOW WILL WEAKEN WEDNESDAY AND THURSDAY AS A RIDGE BUILDS
OVER THE REGION. A RELATIVELY WEAK FRONT WILL PROBABLY REACH THE
AREA FRIDAY.   MCDONNAL

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.
     GALE WATCH FOR MONDAY NIGHT AND TUESDAY CENTRAL STRAIT AND
       EAST ENTRANCE STRAIT.

&&

$$

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









000
FXUS66 KSEW 300354
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PDT SUN MAR 29 2015

.SYNOPSIS...A STATIONARY FRONT WILL BRING RAIN AT TIMES TO NORTHERN
AND COASTAL SECTIONS THROUGH MONDAY. A COLD FRONT WILL SPREAD RAIN
ACROSS THE AREA MONDAY NIGHT. AN UPPER LEVEL TROUGH WILL SETTLE OVER
THE PACIFIC NORTHWEST TUESDAY AND WEDNESDAY PROVIDING COOL SHOWERY
WEATHER. SHOWERS WILL DECREASE THURSDAY...THEN RAIN DEVELOPS FRIDAY
AS THE NEXT TROUGH MOVES OVER THE REGION.

&&

.SHORT TERM...THE STATIONARY FRONT THAT HAS BROUGHT RAIN AT TIMES TO
THE COAST AND NORTHERN INTERIOR FOR THE LAST 24 HOURS OR SO WILL
CONTINUE TO DO SO FOR ANOTHER 24. TOMORROW WILL BE ONE LAST DAY IN
THE WARM SECTOR AND HIGH TEMPERATURES ARE FORECAST TO BE IN THE 60S.
A COLD FRONT WILL FINALLY MOVE THROUGH MONDAY NIGHT...SPREADING RAIN
OVER THE WHOLE AREA.

SHOWERS AND BREEZY CONDITIONS WILL FOLLOW ON TUESDAY. HEIGHTS WILL
FALL SIGNIFICANTLY WITH HIGH TEMPERATURES ONLY REACHING THE LOW TO
MID 50S. THE SNOW LEVEL WILL FALL TO AS LOW AS 3000 FEET. THIS MEANS
THERE WILL BE SNOW IN THE PASSES AND ALSO IN A PUGET SOUND
CONVERGENCE ZONE IN THE MOUNTAINS. A SNOW ADVISORY COULD BE NEEDED.

SHOWERS TAPER WEDNESDAY. A LITTLE WARMING IS LIKELY. BURKE

.LONG TERM...PREVIOUS DISCUSSION...THE GFS/ECMWF ARE COMING INTO
BETTER AGREEMENT SHOWING A SHORT WAVE RIDGE ON THURSDAY...THE
ANOTHER TROUGH ARRIVING FRIDAY. THERE COULD STILL BE SOME WEAK
DIURNAL SHOWER ACTIVITY THURSDAY AND THE GFS DOES KEEP SOME SPOTTY
LIGHT QPF AROUND. LEFT A CHANCE OF SHOWERS IN THE FORECAST FOR NOW
BUT POPS MIGHT NEED TO BE PULLED IF MODELS CONTINUE WITH THE RIDGE
SOLUTION.

A FRONT BRINGS RAIN INTO WESTERN WASHINGTON ON FRIDAY...THEN A
TROUGH MOVES INTO THE REGION OVER THE WEEKEND. IT WILL BE COOL AND
UNSETTLED WITH SHOWERS ACROSS THE AREA. SNOW LEVELS WILL BE LOW AT
AROUND 3000 FEET BUT THE SHOWERY PATTERN IS PROBABLY NOT CONDUCIVE
FOR MUCH SNOW ACCUMULATION. MERCER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A BROAD FLAT UPPER RIDGE WILL REMAIN OVER THE REGION
TONIGHT...THEN WEAKEN AND MOVE EAST MONDAY AS A COLD FRONT MOVES
INTO THE COASTAL WATERS. WESTERLY FLOW ALOFT TONIGHT WILL BACK TO
SOUTHWEST MONDAY. THE AIR MASS WILL BE GENERALLY STABLE AND MOIST
BELOW 10000 FT.

MOSTLY VFR CONDITIONS ACROSS THE FORECAST AREA THIS EVENING WITH
SCT030-040 BKN050-070 OVC090-120. THERE ARE AREAS -- MAINLY ALONG
THE COAST AND IN THE NORTH INTERIOR -- OF OVC023-030 WITH -RA. ON
THE WHOLE THERE WILL NOT BE MUCH CHANGE THROUGH MONDAY.

KSEA...SOUTH WIND 5-10 KT.   MCDONNAL

&&

.MARINE...A RIDGE OVER WESTERN WASHINGTON WILL WEAKEN EARLY MONDAY
AS A COLD FRONT MOVES INTO THE COASTAL WATERS. THE FRONT WILL MOVE
INLAND MONDAY EVENING...FOLLOWED BY STRONG ONSHORE FLOW MONDAY NIGHT
AND TUESDAY. SMALL CRAFT ADVISORY CONDITIONS WILL PREVAIL FOR MOST
OF THE MARINE ZONES THROUGH THIS PERIOD...AND WESTERLY GALES ARE
POSSIBLE IN THE CENTRAL AND EASTERN STRAIT OF JUAN DE FUCA LATER
MONDAY NIGHT AND TUESDAY.

ONSHORE FLOW WILL WEAKEN WEDNESDAY AND THURSDAY AS A RIDGE BUILDS
OVER THE REGION. A RELATIVELY WEAK FRONT WILL PROBABLY REACH THE
AREA FRIDAY.   MCDONNAL

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.
     GALE WATCH FOR MONDAY NIGHT AND TUESDAY CENTRAL STRAIT AND
       EAST ENTRANCE STRAIT.

&&

$$

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









000
FXUS66 KSEW 292206
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PDT SUN MAR 29 2015

.SYNOPSIS...A STALLED WARM FRONT WILL BRING RAIN AT TIMES TO NORTHERN
PARTS OF WESTERN WASHINGTON THROUGH MONDAY. THE ASSOCIATED COLD FRONT
WILL BRING WIDESPREAD RAIN TO THE AREA MONDAY NIGHT. AN UPPER LEVEL
TROUGH WILL SETTLE OVER THE PACIFIC NORTHWEST TUESDAY AND WEDNESDAY
PROVIDING COOL AND SHOWERY WEATHER. SHOWERS WILL DECREASE
THURSDAY...THEN RAIN DEVELOPS FRIDAY AS THE NEXT TROUGH MOVES OVER THE
REGION. UNSETTLED WEATHER WILL CONTINUE INTO THE WEEKEND.

&&

.SHORT TERM...WARM ADVECTION RAIN CONTINUES LATE THIS AFTERNOON FROM
THE N COAST/OLYMPIC PENINSULA ACROSS THE N INTERIOR. OVER A HALF INCH
OF RAIN FELL THE PAST 12 HOURS ON THE N COAST AND AROUND A QUARTER INCH
AT A FEW OTHER SPOTS TOWARD THE CANADIAN BORDER. RADAR AND OBS SHOW
LIGHT RAIN BRIEFLY EXTENDING S INTO HOQUIAM BUT IS NOT MAKING MUCH
PROGRESS INLAND. MESO MODELS ARE MOSTLY KEEPING THE INTERIOR DRY FROM
AROUND EVERETT SWD TONIGHT. HOWEVER...THE LATEST HRRR DOES SHOW SOME
SPOTTY LIGHT QPF JUST N OF SEATTLE SO THE FORECAST WAS TWEAKED A BIT TO
THROW IN SOME LOW POPS FOR THE EVERETT/BREMERTON/AND E PUGET LOWLAND
ZONES FOR THIS EVENING. SPRINKLES ARE POSSIBLE FURTHER S THIS EVENING
BUT NOTHING MEASURABLE IS EXPECTED.

MODELS DEEPEN THE ASSOCIATED SURFACE LOW OFFSHORE TO ABOUT 1000 MB AS
IT TRACKS INTO S/CENTRAL B.C. MONDAY AFTERNOON. ONCE THE LOW MOVES
INLAND...THE TRAILING FRONT AND UPPER TROUGH WILL MOVE INTO THE REGION.
THE GFS/ECMWF/AND MESO MODELS ALL SHOW WIDESPREAD RAIN WITH THE FRONT
MONDAY NIGHT. A COOLER AND UNSTABLE AIR MASS WILL FOLLOW THE FRONT WITH
RAPIDLY LOWERING SNOW LEVELS LATER MONDAY NIGHT INTO TUESDAY. SNOW
LEVELS WILL START OFF CLOSE TO 7000 FEET BUT WILL FALL TO ROUGHLY 3000
FEET BY TUESDAY MORNING. A FEW INCHES OF SNOW ARE POSSIBLE THROUGH
TUESDAY MORNING...MAINLY AT THE HIGHER PASSES AND SKI RESORTS. QPF OFF
THE NAM-12 AND GFS IMPLY MOSTLY SUB ADVISORY AMOUNTS OF SNOW. LOCALLY
HIGHER AMOUNTS OF SNOW COULD FALL IN THE CASCADES OF SNOHOMISH/KING
COUNTY IF A PUGET SOUND CONVERGENCE ZONE DEVELOPS. THIS WOULD MAINLY
AFFECT STEVENS PASS IF THE LATEST MESO MODELS ARE CORRECT. WILL NEED TO
KEEP A WATCH ON THIS FEATURE TUESDAY.

SHOWERS LINGER INTO WEDNESDAY AS ADDITIONAL UPPER LEVEL ENERGY DRIVES
SE THROUGH THE REGION. THE GFS SHOWS A -34C COLD POOL AT 500 MB
SETTLING OVER THE AREA AND LI`S GO NEGATIVE BOTH TUESDAY AND WEDNESDAY
AFTERNOON. THIS LOOKS LIKE THE TYPICAL SPRING PATTERN WITH SHOWERS AND
ISOLATED AFTERNOON THUNDERSTORMS. HIGH TEMPERATURES WILL BE MUCH
COOLER...ONLY IN THE LOW TO MID 50S.

.LONG TERM...THE GFS/ECMWF ARE COMING INTO BETTER AGREEMENT SHOWING A
SHORT WAVE RIDGE ON THURSDAY...THE ANOTHER TROUGH ARRIVING FRIDAY.
THERE COULD STILL BE SOME WEAK DIURNAL SHOWER ACTIVITY THURSDAY AND THE
GFS DOES KEEP SOME SPOTTY LIGHT QPF AROUND. LEFT A CHANCE OF SHOWERS IN
THE FORECAST FOR NOW BUT POPS MIGHT NEED TO BE PULLED IF MODELS
CONTINUE WITH THE RIDGE SOLUTION.

A FRONT BRINGS RAIN INTO WESTERN WASHINGTON ON FRIDAY...THEN A TROUGH
MOVES INTO THE REGION OVER THE WEEKEND. IT WILL BE COOL AND UNSETTLED
WITH SHOWERS ACROSS THE AREA. SNOW LEVELS WILL BE LOW AT AROUND 3000
FEET BUT THE SHOWERY PATTERN IS PROBABLY NOT CONDUCIVE FOR MUCH SNOW
ACCUMULATION. MERCER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A BROAD FLAT UPPER LEVEL RIDGE OVER THE PACIFIC NORTHWEST
WILL MAINTAIN FAIRLY MOIST WESTERLY FLOW ALOFT OVER W WA THROUGH MONDAY
MORNING. A NEARLY STATIONARY FRONT IS DRAPED ACROSS SOUTHERN B.C. AND
EXTENDS SW FROM VANCOUVER ISLAND ACROSS THE OFFSHORE WATERS. THE FRONT
WILL CONTINUE TO BRING A LITTLE LIGHT RAIN AT TIMES ACROSS THE FAR N
PART OF W WA...FROM THE NORTH COAST TO KCLM TO KBLI.

VFR CONDITIONS ARE EXPECTED TO CONTINUE OVER THE INTERIOR WITH CIGS
GENERALLY BKN040-060 WITH HIGHER OVC LAYERS. CIGS WILL PROBABLY BE A
LITTLE LOWER OVER THE N INTERIOR. MVFR CIGS ARE EXPECTED ON THE
COAST WITH AREAS OF IFR CONDITIONS OVER THE N COAST CLOSER TO THE
STATIONARY FRONT.

A COLD FRONT WILL APPROACH THE AREA MONDAY...CROSSING THE COAST LATE
MONDAY AFTERNOON AND THE INTERIOR MONDAY EVENING.

KSEA...VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH TONIGHT WITH
CLOUD LAYERS GENERALLY SCT-BKN050-060 BKN-OVC080-100. SURFACE WINDS
WILL REMAIN SOUTHERLY 5-10 KT. KAM

&&

.MARINE...A SMALL WEAK SURFACE RIDGE WILL REMAIN OVER WESTERN
WASHINGTON THROUGH MONDAY MORNING. LOWER PRESSURE WILL CONTINUE OVER
BRITISH COLUMBIA AND THE WATERS OFFSHORE WHERE A BAROCLINIC ZONE
EXTENDS SOUTHWESTWARD FROM VANCOUVER ISLAND. THIS PATTERN WILL
RESULT IN MODERATE S FLOW ACROSS THE COASTAL WATERS THROUGH TONIGHT.

S FLOW OVER THE INLAND WATERS THIS AFTERNOON IS TAKING ITS SWEET
TIME WEAKENING. OBSERVED WINDS ARE TRENDING WEAKER...AND THE 20Z
HRRR DROPS THE WINDS BELOW SCA AT 3 PM...BUT THE WINDS ARE STILL
TRYING HARD NOT TO COOPERATE. I WILL EXTEND THE INLAND WATERS SCA TO
5 PM TO COVER ANY NON-COOPERATIVE STRAGGLERS. OTHERWISE THE INLAND
WATERS WINDS SHOULD REMAIN BELOW ADVISORY CRITERIA TONIGHT.

AN APPROACHING COLD FRONT WILL INCREASE WINDS BACK TO ADVISORY
LEVELS MONDAY MORNING. THE COLD FRONT IS EXPECTED TO CROSS THE COAST
LATE MONDAY AFTERNOON AND THE INLAND WATERS MONDAY EVENING. MODERATE
TO STRONG WESTERLY ONSHORE FLOW WILL DEVELOP OVER W WA MONDAY NIGHT
BEHIND THE COLD FRONT. GALE FORCE WINDS ARE LIKELY IN THE CENTRAL
AND E STRAIT OF JUAN DE FUCA MONDAY NIGHT AND TUESDAY...WITH
ADVISORY WINDS OVER THE WATERS ADJACENT TO THE STRAIT.

THERE WILL BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS THROUGH TUESDAY AND OVER THE OUTER WATERS INTO WEDNESDAY. BAR
CONDITIONS WILL BE ROUGH AS WELL.

WEAKER ONSHORE FLOW WILL CONTINUE THROUGH MID-WEEK...BUT WILL BE
JUST STRONG ENOUGH TO RISE TO ADVISORY LEVELS IN THE CENTRAL AND
EAST STRAIT TUESDAY NIGHT AND WEDNESDAY NIGHT. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.
     GALE WATCH FOR MONDAY NIGHT AND TUESDAY CENTRAL STRAIT AND
       EAST ENTRANCE STRAIT.

&&

$$

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















000
FXUS66 KSEW 292206
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PDT SUN MAR 29 2015

.SYNOPSIS...A STALLED WARM FRONT WILL BRING RAIN AT TIMES TO NORTHERN
PARTS OF WESTERN WASHINGTON THROUGH MONDAY. THE ASSOCIATED COLD FRONT
WILL BRING WIDESPREAD RAIN TO THE AREA MONDAY NIGHT. AN UPPER LEVEL
TROUGH WILL SETTLE OVER THE PACIFIC NORTHWEST TUESDAY AND WEDNESDAY
PROVIDING COOL AND SHOWERY WEATHER. SHOWERS WILL DECREASE
THURSDAY...THEN RAIN DEVELOPS FRIDAY AS THE NEXT TROUGH MOVES OVER THE
REGION. UNSETTLED WEATHER WILL CONTINUE INTO THE WEEKEND.

&&

.SHORT TERM...WARM ADVECTION RAIN CONTINUES LATE THIS AFTERNOON FROM
THE N COAST/OLYMPIC PENINSULA ACROSS THE N INTERIOR. OVER A HALF INCH
OF RAIN FELL THE PAST 12 HOURS ON THE N COAST AND AROUND A QUARTER INCH
AT A FEW OTHER SPOTS TOWARD THE CANADIAN BORDER. RADAR AND OBS SHOW
LIGHT RAIN BRIEFLY EXTENDING S INTO HOQUIAM BUT IS NOT MAKING MUCH
PROGRESS INLAND. MESO MODELS ARE MOSTLY KEEPING THE INTERIOR DRY FROM
AROUND EVERETT SWD TONIGHT. HOWEVER...THE LATEST HRRR DOES SHOW SOME
SPOTTY LIGHT QPF JUST N OF SEATTLE SO THE FORECAST WAS TWEAKED A BIT TO
THROW IN SOME LOW POPS FOR THE EVERETT/BREMERTON/AND E PUGET LOWLAND
ZONES FOR THIS EVENING. SPRINKLES ARE POSSIBLE FURTHER S THIS EVENING
BUT NOTHING MEASURABLE IS EXPECTED.

MODELS DEEPEN THE ASSOCIATED SURFACE LOW OFFSHORE TO ABOUT 1000 MB AS
IT TRACKS INTO S/CENTRAL B.C. MONDAY AFTERNOON. ONCE THE LOW MOVES
INLAND...THE TRAILING FRONT AND UPPER TROUGH WILL MOVE INTO THE REGION.
THE GFS/ECMWF/AND MESO MODELS ALL SHOW WIDESPREAD RAIN WITH THE FRONT
MONDAY NIGHT. A COOLER AND UNSTABLE AIR MASS WILL FOLLOW THE FRONT WITH
RAPIDLY LOWERING SNOW LEVELS LATER MONDAY NIGHT INTO TUESDAY. SNOW
LEVELS WILL START OFF CLOSE TO 7000 FEET BUT WILL FALL TO ROUGHLY 3000
FEET BY TUESDAY MORNING. A FEW INCHES OF SNOW ARE POSSIBLE THROUGH
TUESDAY MORNING...MAINLY AT THE HIGHER PASSES AND SKI RESORTS. QPF OFF
THE NAM-12 AND GFS IMPLY MOSTLY SUB ADVISORY AMOUNTS OF SNOW. LOCALLY
HIGHER AMOUNTS OF SNOW COULD FALL IN THE CASCADES OF SNOHOMISH/KING
COUNTY IF A PUGET SOUND CONVERGENCE ZONE DEVELOPS. THIS WOULD MAINLY
AFFECT STEVENS PASS IF THE LATEST MESO MODELS ARE CORRECT. WILL NEED TO
KEEP A WATCH ON THIS FEATURE TUESDAY.

SHOWERS LINGER INTO WEDNESDAY AS ADDITIONAL UPPER LEVEL ENERGY DRIVES
SE THROUGH THE REGION. THE GFS SHOWS A -34C COLD POOL AT 500 MB
SETTLING OVER THE AREA AND LI`S GO NEGATIVE BOTH TUESDAY AND WEDNESDAY
AFTERNOON. THIS LOOKS LIKE THE TYPICAL SPRING PATTERN WITH SHOWERS AND
ISOLATED AFTERNOON THUNDERSTORMS. HIGH TEMPERATURES WILL BE MUCH
COOLER...ONLY IN THE LOW TO MID 50S.

.LONG TERM...THE GFS/ECMWF ARE COMING INTO BETTER AGREEMENT SHOWING A
SHORT WAVE RIDGE ON THURSDAY...THE ANOTHER TROUGH ARRIVING FRIDAY.
THERE COULD STILL BE SOME WEAK DIURNAL SHOWER ACTIVITY THURSDAY AND THE
GFS DOES KEEP SOME SPOTTY LIGHT QPF AROUND. LEFT A CHANCE OF SHOWERS IN
THE FORECAST FOR NOW BUT POPS MIGHT NEED TO BE PULLED IF MODELS
CONTINUE WITH THE RIDGE SOLUTION.

A FRONT BRINGS RAIN INTO WESTERN WASHINGTON ON FRIDAY...THEN A TROUGH
MOVES INTO THE REGION OVER THE WEEKEND. IT WILL BE COOL AND UNSETTLED
WITH SHOWERS ACROSS THE AREA. SNOW LEVELS WILL BE LOW AT AROUND 3000
FEET BUT THE SHOWERY PATTERN IS PROBABLY NOT CONDUCIVE FOR MUCH SNOW
ACCUMULATION. MERCER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A BROAD FLAT UPPER LEVEL RIDGE OVER THE PACIFIC NORTHWEST
WILL MAINTAIN FAIRLY MOIST WESTERLY FLOW ALOFT OVER W WA THROUGH MONDAY
MORNING. A NEARLY STATIONARY FRONT IS DRAPED ACROSS SOUTHERN B.C. AND
EXTENDS SW FROM VANCOUVER ISLAND ACROSS THE OFFSHORE WATERS. THE FRONT
WILL CONTINUE TO BRING A LITTLE LIGHT RAIN AT TIMES ACROSS THE FAR N
PART OF W WA...FROM THE NORTH COAST TO KCLM TO KBLI.

VFR CONDITIONS ARE EXPECTED TO CONTINUE OVER THE INTERIOR WITH CIGS
GENERALLY BKN040-060 WITH HIGHER OVC LAYERS. CIGS WILL PROBABLY BE A
LITTLE LOWER OVER THE N INTERIOR. MVFR CIGS ARE EXPECTED ON THE
COAST WITH AREAS OF IFR CONDITIONS OVER THE N COAST CLOSER TO THE
STATIONARY FRONT.

A COLD FRONT WILL APPROACH THE AREA MONDAY...CROSSING THE COAST LATE
MONDAY AFTERNOON AND THE INTERIOR MONDAY EVENING.

KSEA...VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH TONIGHT WITH
CLOUD LAYERS GENERALLY SCT-BKN050-060 BKN-OVC080-100. SURFACE WINDS
WILL REMAIN SOUTHERLY 5-10 KT. KAM

&&

.MARINE...A SMALL WEAK SURFACE RIDGE WILL REMAIN OVER WESTERN
WASHINGTON THROUGH MONDAY MORNING. LOWER PRESSURE WILL CONTINUE OVER
BRITISH COLUMBIA AND THE WATERS OFFSHORE WHERE A BAROCLINIC ZONE
EXTENDS SOUTHWESTWARD FROM VANCOUVER ISLAND. THIS PATTERN WILL
RESULT IN MODERATE S FLOW ACROSS THE COASTAL WATERS THROUGH TONIGHT.

S FLOW OVER THE INLAND WATERS THIS AFTERNOON IS TAKING ITS SWEET
TIME WEAKENING. OBSERVED WINDS ARE TRENDING WEAKER...AND THE 20Z
HRRR DROPS THE WINDS BELOW SCA AT 3 PM...BUT THE WINDS ARE STILL
TRYING HARD NOT TO COOPERATE. I WILL EXTEND THE INLAND WATERS SCA TO
5 PM TO COVER ANY NON-COOPERATIVE STRAGGLERS. OTHERWISE THE INLAND
WATERS WINDS SHOULD REMAIN BELOW ADVISORY CRITERIA TONIGHT.

AN APPROACHING COLD FRONT WILL INCREASE WINDS BACK TO ADVISORY
LEVELS MONDAY MORNING. THE COLD FRONT IS EXPECTED TO CROSS THE COAST
LATE MONDAY AFTERNOON AND THE INLAND WATERS MONDAY EVENING. MODERATE
TO STRONG WESTERLY ONSHORE FLOW WILL DEVELOP OVER W WA MONDAY NIGHT
BEHIND THE COLD FRONT. GALE FORCE WINDS ARE LIKELY IN THE CENTRAL
AND E STRAIT OF JUAN DE FUCA MONDAY NIGHT AND TUESDAY...WITH
ADVISORY WINDS OVER THE WATERS ADJACENT TO THE STRAIT.

THERE WILL BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS THROUGH TUESDAY AND OVER THE OUTER WATERS INTO WEDNESDAY. BAR
CONDITIONS WILL BE ROUGH AS WELL.

WEAKER ONSHORE FLOW WILL CONTINUE THROUGH MID-WEEK...BUT WILL BE
JUST STRONG ENOUGH TO RISE TO ADVISORY LEVELS IN THE CENTRAL AND
EAST STRAIT TUESDAY NIGHT AND WEDNESDAY NIGHT. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.
     GALE WATCH FOR MONDAY NIGHT AND TUESDAY CENTRAL STRAIT AND
       EAST ENTRANCE STRAIT.

&&

$$

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
















000
FXUS66 KSEW 292206
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PDT SUN MAR 29 2015

.SYNOPSIS...A STALLED WARM FRONT WILL BRING RAIN AT TIMES TO NORTHERN
PARTS OF WESTERN WASHINGTON THROUGH MONDAY. THE ASSOCIATED COLD FRONT
WILL BRING WIDESPREAD RAIN TO THE AREA MONDAY NIGHT. AN UPPER LEVEL
TROUGH WILL SETTLE OVER THE PACIFIC NORTHWEST TUESDAY AND WEDNESDAY
PROVIDING COOL AND SHOWERY WEATHER. SHOWERS WILL DECREASE
THURSDAY...THEN RAIN DEVELOPS FRIDAY AS THE NEXT TROUGH MOVES OVER THE
REGION. UNSETTLED WEATHER WILL CONTINUE INTO THE WEEKEND.

&&

.SHORT TERM...WARM ADVECTION RAIN CONTINUES LATE THIS AFTERNOON FROM
THE N COAST/OLYMPIC PENINSULA ACROSS THE N INTERIOR. OVER A HALF INCH
OF RAIN FELL THE PAST 12 HOURS ON THE N COAST AND AROUND A QUARTER INCH
AT A FEW OTHER SPOTS TOWARD THE CANADIAN BORDER. RADAR AND OBS SHOW
LIGHT RAIN BRIEFLY EXTENDING S INTO HOQUIAM BUT IS NOT MAKING MUCH
PROGRESS INLAND. MESO MODELS ARE MOSTLY KEEPING THE INTERIOR DRY FROM
AROUND EVERETT SWD TONIGHT. HOWEVER...THE LATEST HRRR DOES SHOW SOME
SPOTTY LIGHT QPF JUST N OF SEATTLE SO THE FORECAST WAS TWEAKED A BIT TO
THROW IN SOME LOW POPS FOR THE EVERETT/BREMERTON/AND E PUGET LOWLAND
ZONES FOR THIS EVENING. SPRINKLES ARE POSSIBLE FURTHER S THIS EVENING
BUT NOTHING MEASURABLE IS EXPECTED.

MODELS DEEPEN THE ASSOCIATED SURFACE LOW OFFSHORE TO ABOUT 1000 MB AS
IT TRACKS INTO S/CENTRAL B.C. MONDAY AFTERNOON. ONCE THE LOW MOVES
INLAND...THE TRAILING FRONT AND UPPER TROUGH WILL MOVE INTO THE REGION.
THE GFS/ECMWF/AND MESO MODELS ALL SHOW WIDESPREAD RAIN WITH THE FRONT
MONDAY NIGHT. A COOLER AND UNSTABLE AIR MASS WILL FOLLOW THE FRONT WITH
RAPIDLY LOWERING SNOW LEVELS LATER MONDAY NIGHT INTO TUESDAY. SNOW
LEVELS WILL START OFF CLOSE TO 7000 FEET BUT WILL FALL TO ROUGHLY 3000
FEET BY TUESDAY MORNING. A FEW INCHES OF SNOW ARE POSSIBLE THROUGH
TUESDAY MORNING...MAINLY AT THE HIGHER PASSES AND SKI RESORTS. QPF OFF
THE NAM-12 AND GFS IMPLY MOSTLY SUB ADVISORY AMOUNTS OF SNOW. LOCALLY
HIGHER AMOUNTS OF SNOW COULD FALL IN THE CASCADES OF SNOHOMISH/KING
COUNTY IF A PUGET SOUND CONVERGENCE ZONE DEVELOPS. THIS WOULD MAINLY
AFFECT STEVENS PASS IF THE LATEST MESO MODELS ARE CORRECT. WILL NEED TO
KEEP A WATCH ON THIS FEATURE TUESDAY.

SHOWERS LINGER INTO WEDNESDAY AS ADDITIONAL UPPER LEVEL ENERGY DRIVES
SE THROUGH THE REGION. THE GFS SHOWS A -34C COLD POOL AT 500 MB
SETTLING OVER THE AREA AND LI`S GO NEGATIVE BOTH TUESDAY AND WEDNESDAY
AFTERNOON. THIS LOOKS LIKE THE TYPICAL SPRING PATTERN WITH SHOWERS AND
ISOLATED AFTERNOON THUNDERSTORMS. HIGH TEMPERATURES WILL BE MUCH
COOLER...ONLY IN THE LOW TO MID 50S.

.LONG TERM...THE GFS/ECMWF ARE COMING INTO BETTER AGREEMENT SHOWING A
SHORT WAVE RIDGE ON THURSDAY...THE ANOTHER TROUGH ARRIVING FRIDAY.
THERE COULD STILL BE SOME WEAK DIURNAL SHOWER ACTIVITY THURSDAY AND THE
GFS DOES KEEP SOME SPOTTY LIGHT QPF AROUND. LEFT A CHANCE OF SHOWERS IN
THE FORECAST FOR NOW BUT POPS MIGHT NEED TO BE PULLED IF MODELS
CONTINUE WITH THE RIDGE SOLUTION.

A FRONT BRINGS RAIN INTO WESTERN WASHINGTON ON FRIDAY...THEN A TROUGH
MOVES INTO THE REGION OVER THE WEEKEND. IT WILL BE COOL AND UNSETTLED
WITH SHOWERS ACROSS THE AREA. SNOW LEVELS WILL BE LOW AT AROUND 3000
FEET BUT THE SHOWERY PATTERN IS PROBABLY NOT CONDUCIVE FOR MUCH SNOW
ACCUMULATION. MERCER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A BROAD FLAT UPPER LEVEL RIDGE OVER THE PACIFIC NORTHWEST
WILL MAINTAIN FAIRLY MOIST WESTERLY FLOW ALOFT OVER W WA THROUGH MONDAY
MORNING. A NEARLY STATIONARY FRONT IS DRAPED ACROSS SOUTHERN B.C. AND
EXTENDS SW FROM VANCOUVER ISLAND ACROSS THE OFFSHORE WATERS. THE FRONT
WILL CONTINUE TO BRING A LITTLE LIGHT RAIN AT TIMES ACROSS THE FAR N
PART OF W WA...FROM THE NORTH COAST TO KCLM TO KBLI.

VFR CONDITIONS ARE EXPECTED TO CONTINUE OVER THE INTERIOR WITH CIGS
GENERALLY BKN040-060 WITH HIGHER OVC LAYERS. CIGS WILL PROBABLY BE A
LITTLE LOWER OVER THE N INTERIOR. MVFR CIGS ARE EXPECTED ON THE
COAST WITH AREAS OF IFR CONDITIONS OVER THE N COAST CLOSER TO THE
STATIONARY FRONT.

A COLD FRONT WILL APPROACH THE AREA MONDAY...CROSSING THE COAST LATE
MONDAY AFTERNOON AND THE INTERIOR MONDAY EVENING.

KSEA...VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH TONIGHT WITH
CLOUD LAYERS GENERALLY SCT-BKN050-060 BKN-OVC080-100. SURFACE WINDS
WILL REMAIN SOUTHERLY 5-10 KT. KAM

&&

.MARINE...A SMALL WEAK SURFACE RIDGE WILL REMAIN OVER WESTERN
WASHINGTON THROUGH MONDAY MORNING. LOWER PRESSURE WILL CONTINUE OVER
BRITISH COLUMBIA AND THE WATERS OFFSHORE WHERE A BAROCLINIC ZONE
EXTENDS SOUTHWESTWARD FROM VANCOUVER ISLAND. THIS PATTERN WILL
RESULT IN MODERATE S FLOW ACROSS THE COASTAL WATERS THROUGH TONIGHT.

S FLOW OVER THE INLAND WATERS THIS AFTERNOON IS TAKING ITS SWEET
TIME WEAKENING. OBSERVED WINDS ARE TRENDING WEAKER...AND THE 20Z
HRRR DROPS THE WINDS BELOW SCA AT 3 PM...BUT THE WINDS ARE STILL
TRYING HARD NOT TO COOPERATE. I WILL EXTEND THE INLAND WATERS SCA TO
5 PM TO COVER ANY NON-COOPERATIVE STRAGGLERS. OTHERWISE THE INLAND
WATERS WINDS SHOULD REMAIN BELOW ADVISORY CRITERIA TONIGHT.

AN APPROACHING COLD FRONT WILL INCREASE WINDS BACK TO ADVISORY
LEVELS MONDAY MORNING. THE COLD FRONT IS EXPECTED TO CROSS THE COAST
LATE MONDAY AFTERNOON AND THE INLAND WATERS MONDAY EVENING. MODERATE
TO STRONG WESTERLY ONSHORE FLOW WILL DEVELOP OVER W WA MONDAY NIGHT
BEHIND THE COLD FRONT. GALE FORCE WINDS ARE LIKELY IN THE CENTRAL
AND E STRAIT OF JUAN DE FUCA MONDAY NIGHT AND TUESDAY...WITH
ADVISORY WINDS OVER THE WATERS ADJACENT TO THE STRAIT.

THERE WILL BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS THROUGH TUESDAY AND OVER THE OUTER WATERS INTO WEDNESDAY. BAR
CONDITIONS WILL BE ROUGH AS WELL.

WEAKER ONSHORE FLOW WILL CONTINUE THROUGH MID-WEEK...BUT WILL BE
JUST STRONG ENOUGH TO RISE TO ADVISORY LEVELS IN THE CENTRAL AND
EAST STRAIT TUESDAY NIGHT AND WEDNESDAY NIGHT. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.
     GALE WATCH FOR MONDAY NIGHT AND TUESDAY CENTRAL STRAIT AND
       EAST ENTRANCE STRAIT.

&&

$$

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















000
FXUS66 KSEW 292206
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PDT SUN MAR 29 2015

.SYNOPSIS...A STALLED WARM FRONT WILL BRING RAIN AT TIMES TO NORTHERN
PARTS OF WESTERN WASHINGTON THROUGH MONDAY. THE ASSOCIATED COLD FRONT
WILL BRING WIDESPREAD RAIN TO THE AREA MONDAY NIGHT. AN UPPER LEVEL
TROUGH WILL SETTLE OVER THE PACIFIC NORTHWEST TUESDAY AND WEDNESDAY
PROVIDING COOL AND SHOWERY WEATHER. SHOWERS WILL DECREASE
THURSDAY...THEN RAIN DEVELOPS FRIDAY AS THE NEXT TROUGH MOVES OVER THE
REGION. UNSETTLED WEATHER WILL CONTINUE INTO THE WEEKEND.

&&

.SHORT TERM...WARM ADVECTION RAIN CONTINUES LATE THIS AFTERNOON FROM
THE N COAST/OLYMPIC PENINSULA ACROSS THE N INTERIOR. OVER A HALF INCH
OF RAIN FELL THE PAST 12 HOURS ON THE N COAST AND AROUND A QUARTER INCH
AT A FEW OTHER SPOTS TOWARD THE CANADIAN BORDER. RADAR AND OBS SHOW
LIGHT RAIN BRIEFLY EXTENDING S INTO HOQUIAM BUT IS NOT MAKING MUCH
PROGRESS INLAND. MESO MODELS ARE MOSTLY KEEPING THE INTERIOR DRY FROM
AROUND EVERETT SWD TONIGHT. HOWEVER...THE LATEST HRRR DOES SHOW SOME
SPOTTY LIGHT QPF JUST N OF SEATTLE SO THE FORECAST WAS TWEAKED A BIT TO
THROW IN SOME LOW POPS FOR THE EVERETT/BREMERTON/AND E PUGET LOWLAND
ZONES FOR THIS EVENING. SPRINKLES ARE POSSIBLE FURTHER S THIS EVENING
BUT NOTHING MEASURABLE IS EXPECTED.

MODELS DEEPEN THE ASSOCIATED SURFACE LOW OFFSHORE TO ABOUT 1000 MB AS
IT TRACKS INTO S/CENTRAL B.C. MONDAY AFTERNOON. ONCE THE LOW MOVES
INLAND...THE TRAILING FRONT AND UPPER TROUGH WILL MOVE INTO THE REGION.
THE GFS/ECMWF/AND MESO MODELS ALL SHOW WIDESPREAD RAIN WITH THE FRONT
MONDAY NIGHT. A COOLER AND UNSTABLE AIR MASS WILL FOLLOW THE FRONT WITH
RAPIDLY LOWERING SNOW LEVELS LATER MONDAY NIGHT INTO TUESDAY. SNOW
LEVELS WILL START OFF CLOSE TO 7000 FEET BUT WILL FALL TO ROUGHLY 3000
FEET BY TUESDAY MORNING. A FEW INCHES OF SNOW ARE POSSIBLE THROUGH
TUESDAY MORNING...MAINLY AT THE HIGHER PASSES AND SKI RESORTS. QPF OFF
THE NAM-12 AND GFS IMPLY MOSTLY SUB ADVISORY AMOUNTS OF SNOW. LOCALLY
HIGHER AMOUNTS OF SNOW COULD FALL IN THE CASCADES OF SNOHOMISH/KING
COUNTY IF A PUGET SOUND CONVERGENCE ZONE DEVELOPS. THIS WOULD MAINLY
AFFECT STEVENS PASS IF THE LATEST MESO MODELS ARE CORRECT. WILL NEED TO
KEEP A WATCH ON THIS FEATURE TUESDAY.

SHOWERS LINGER INTO WEDNESDAY AS ADDITIONAL UPPER LEVEL ENERGY DRIVES
SE THROUGH THE REGION. THE GFS SHOWS A -34C COLD POOL AT 500 MB
SETTLING OVER THE AREA AND LI`S GO NEGATIVE BOTH TUESDAY AND WEDNESDAY
AFTERNOON. THIS LOOKS LIKE THE TYPICAL SPRING PATTERN WITH SHOWERS AND
ISOLATED AFTERNOON THUNDERSTORMS. HIGH TEMPERATURES WILL BE MUCH
COOLER...ONLY IN THE LOW TO MID 50S.

.LONG TERM...THE GFS/ECMWF ARE COMING INTO BETTER AGREEMENT SHOWING A
SHORT WAVE RIDGE ON THURSDAY...THE ANOTHER TROUGH ARRIVING FRIDAY.
THERE COULD STILL BE SOME WEAK DIURNAL SHOWER ACTIVITY THURSDAY AND THE
GFS DOES KEEP SOME SPOTTY LIGHT QPF AROUND. LEFT A CHANCE OF SHOWERS IN
THE FORECAST FOR NOW BUT POPS MIGHT NEED TO BE PULLED IF MODELS
CONTINUE WITH THE RIDGE SOLUTION.

A FRONT BRINGS RAIN INTO WESTERN WASHINGTON ON FRIDAY...THEN A TROUGH
MOVES INTO THE REGION OVER THE WEEKEND. IT WILL BE COOL AND UNSETTLED
WITH SHOWERS ACROSS THE AREA. SNOW LEVELS WILL BE LOW AT AROUND 3000
FEET BUT THE SHOWERY PATTERN IS PROBABLY NOT CONDUCIVE FOR MUCH SNOW
ACCUMULATION. MERCER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A BROAD FLAT UPPER LEVEL RIDGE OVER THE PACIFIC NORTHWEST
WILL MAINTAIN FAIRLY MOIST WESTERLY FLOW ALOFT OVER W WA THROUGH MONDAY
MORNING. A NEARLY STATIONARY FRONT IS DRAPED ACROSS SOUTHERN B.C. AND
EXTENDS SW FROM VANCOUVER ISLAND ACROSS THE OFFSHORE WATERS. THE FRONT
WILL CONTINUE TO BRING A LITTLE LIGHT RAIN AT TIMES ACROSS THE FAR N
PART OF W WA...FROM THE NORTH COAST TO KCLM TO KBLI.

VFR CONDITIONS ARE EXPECTED TO CONTINUE OVER THE INTERIOR WITH CIGS
GENERALLY BKN040-060 WITH HIGHER OVC LAYERS. CIGS WILL PROBABLY BE A
LITTLE LOWER OVER THE N INTERIOR. MVFR CIGS ARE EXPECTED ON THE
COAST WITH AREAS OF IFR CONDITIONS OVER THE N COAST CLOSER TO THE
STATIONARY FRONT.

A COLD FRONT WILL APPROACH THE AREA MONDAY...CROSSING THE COAST LATE
MONDAY AFTERNOON AND THE INTERIOR MONDAY EVENING.

KSEA...VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH TONIGHT WITH
CLOUD LAYERS GENERALLY SCT-BKN050-060 BKN-OVC080-100. SURFACE WINDS
WILL REMAIN SOUTHERLY 5-10 KT. KAM

&&

.MARINE...A SMALL WEAK SURFACE RIDGE WILL REMAIN OVER WESTERN
WASHINGTON THROUGH MONDAY MORNING. LOWER PRESSURE WILL CONTINUE OVER
BRITISH COLUMBIA AND THE WATERS OFFSHORE WHERE A BAROCLINIC ZONE
EXTENDS SOUTHWESTWARD FROM VANCOUVER ISLAND. THIS PATTERN WILL
RESULT IN MODERATE S FLOW ACROSS THE COASTAL WATERS THROUGH TONIGHT.

S FLOW OVER THE INLAND WATERS THIS AFTERNOON IS TAKING ITS SWEET
TIME WEAKENING. OBSERVED WINDS ARE TRENDING WEAKER...AND THE 20Z
HRRR DROPS THE WINDS BELOW SCA AT 3 PM...BUT THE WINDS ARE STILL
TRYING HARD NOT TO COOPERATE. I WILL EXTEND THE INLAND WATERS SCA TO
5 PM TO COVER ANY NON-COOPERATIVE STRAGGLERS. OTHERWISE THE INLAND
WATERS WINDS SHOULD REMAIN BELOW ADVISORY CRITERIA TONIGHT.

AN APPROACHING COLD FRONT WILL INCREASE WINDS BACK TO ADVISORY
LEVELS MONDAY MORNING. THE COLD FRONT IS EXPECTED TO CROSS THE COAST
LATE MONDAY AFTERNOON AND THE INLAND WATERS MONDAY EVENING. MODERATE
TO STRONG WESTERLY ONSHORE FLOW WILL DEVELOP OVER W WA MONDAY NIGHT
BEHIND THE COLD FRONT. GALE FORCE WINDS ARE LIKELY IN THE CENTRAL
AND E STRAIT OF JUAN DE FUCA MONDAY NIGHT AND TUESDAY...WITH
ADVISORY WINDS OVER THE WATERS ADJACENT TO THE STRAIT.

THERE WILL BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS THROUGH TUESDAY AND OVER THE OUTER WATERS INTO WEDNESDAY. BAR
CONDITIONS WILL BE ROUGH AS WELL.

WEAKER ONSHORE FLOW WILL CONTINUE THROUGH MID-WEEK...BUT WILL BE
JUST STRONG ENOUGH TO RISE TO ADVISORY LEVELS IN THE CENTRAL AND
EAST STRAIT TUESDAY NIGHT AND WEDNESDAY NIGHT. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.
     GALE WATCH FOR MONDAY NIGHT AND TUESDAY CENTRAL STRAIT AND
       EAST ENTRANCE STRAIT.

&&

$$

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
















000
FXUS66 KSEW 291608
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 AM PDT SUN MAR 29 2015

.SYNOPSIS...A STALLED FRONTAL BOUNDARY WILL BRING SOME LIGHT RAIN AT
TIMES TO THE COAST AND NORTH INTERIOR THROUGH MONDAY. THE FRONT WILL
PUSH INLAND MONDAY NIGHT BRINGING RAIN TO THE REST OF THE AREA. A
TROUGH OF LOW PRESSURE WILL MOVE INTO THE REGION TUESDAY THROUGH THE
END OF NEXT WEEK. THE UPPER TROUGH WILL GIVE COOL AND SHOWERY
WEATHER TO THE AREA AND SNOW LEVELS WILL FALL TO AROUND 3000 FEET IN
THE MOUNTAINS TUESDAY NIGHT OR WEDNESDAY.

&&

.SHORT TERM...RADAR SHOWS WARM ADVECTION RAIN EXTENDING FROM THE N
WA COAST ACROSS THE N INTERIOR OF WRN WA THIS MORNING. EVERETT
REPORTED SOME OFF AND ON SPRINKLES EARLIER AND IT HAS STAYED DRY TO
THE S. THE GFS/NAM-12 APPEAR TO BE PERFORMING WELL AND KEEP QPF
LIMITED TO THE FAR NRN PART OF WRN WA THROUGH MONDAY. ELSEWHERE...IT
WILL BE PARTLY TO MOSTLY CLOUDY WITH HIGHS ABOVE AVERAGE IN THE LOW
TO MID 60S.

AN UPPER TROUGH WILL DIG SWD TOWARD THE PAC NW MONDAY AFTERNOON AS A
1000 MB SURFACE LOW TRACKS INTO CENTRAL BRITISH COLUMBIA. THE
ASSOCIATED COLD FRONT WILL BRING RAIN TO THE COAST BY THE
EVENING...THEN QUICKLY SPREADING INLAND. MODELS DEPICT A RATHER
VIGOROUS SYSTEM WITH MUCH COOLER AIR BEHIND THE FRONT. SNOW LEVELS
AHEAD OF THE FRONT WILL BE AROUND 6000 TO 7000 FEET...THEN FALLING
TO NEAR 3000 FEET BY LATER MONDAY NIGHT AND TUESDAY. STRONG ONSHORE
FLOW AND AN UNSTABLE AIR MASS WILL KEEP SHOWERS AND BREEZY
CONDITIONS GOING THROUGH TUESDAY AFTERNOON. THERE COULD EVEN BE SOME
ISOLATED THUNDERSTORMS GIVEN THE GFS40 FORECAST  LI`S OF -1 TO -2C.
WILL HOLD OFF MENTIONING THUNDER FOR NOW BUT WILL CONSIDER ADDING A
MENTION IN THE NEXT FORECAST PACKAGE. HIGH TEMPERATURES WILL BE
NOTICEABLY COOLER...ONLY IN THE MID 50S TUESDAY. AS FOR THE
MOUNTAINS...THE WRN SLOPES OF THE CASCADES SHOULD PICK UP SEVERAL
INCHES OF SNOW GIVEN SOME ADDED OROGRAPHIC ENHANCEMENT. BECAUSE OF
THE SHOWERY PATTERN IT MAY BE TOUGH TO GET SOLID ADVISORY LEVEL
AMOUNTS OF SNOW. THE EXCEPTION MIGHT BE THE CASCADES NEAR STEVENS
PASS WHERE A CONVERGENCE ZONE MAY FORM. MESO MODELS ARE SHOWING A
HEAVIER QPF BULLSEYE AROUND THE S SNOHOMISH/N KING COUNTY CASCADES
NEAR STEVENS PASS. SOMETHING TO CONSIDER ONCE WE GET CLOSER TO THE
EVENT. MERCER

.LONG TERM...FROM PREVIOUS DISCUSSION...AN UPPER LEVEL TROUGH WILL
GIVE COOL AND SHOWERY WEATHER TO THE AREA ON WEDNESDAY. THURSDAY MAY
SEE SOME DECREASE IN SHOWER ACTIVITY AND A LITTLE MORE SUNSHINE AS A
SHORT WAVE RIDGE MOVES THROUGH THE REGION.

BOTH THE ECMWF AND GFS MODELS SHOW COOL AND SHOWERY CONDITIONS
FRIDAY THROUGH NEXT WEEKEND WITH SNOW LEVELS 2500 TO 3000 FEET IN
THE MOUNTAINS. ENSEMBLES ARE RATHER CONSISTENT IN SHOWING THE CHANGE
TO THE COOLER WEATHER PATTERN WITH AN UPPER TROUGH OVER WESTERN
WASHINGTON. ALBRECHT

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A BROAD FLAT UPPER LEVEL RIDGE OVER THE PACIFIC
NORTHWEST WILL MAINTAIN FAIRLY MOIST WESTERLY FLOW ALOFT OVER W WA
THROUGH MONDAY MORNING. A NEARLY STATIONARY FRONT IS DRAPED ACROSS
SOUTHERN B.C. AND EXTENDS SW FROM VANCOUVER ISLAND ACROSS THE
OFFSHORE WATERS. THE FRONT WILL CONTINUE TO BRING A LITTLE LIGHT
RAIN AT TIMES ACROSS THE FAR N PART OF W WA...FROM KUIL TO KCLM TO
KBLI.

VFR CONDITIONS ARE EXPECTED TO CONTINUE OVER THE INTERIOR WITH CIGS
GENERALLY BKN050-060 WITH HIGHER OVC LAYERS. CIGS WILL PROBABLY BE A
LITTLE LOWER OVER THE N INTERIOR. MVFR CIGS ARE EXPECTED ON THE
COAST WITH POSSIBLE IFR CONDITIONS OVER THE N COAST CLOSER TO THE
STATIONARY FRONT.

A COLD FRONT WILL APPROACH THE AREA MONDAY...CROSSING THE COAST LATE
MONDAY AFTERNOON AND THE INTERIOR MONDAY EVENING.

KSEA...VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH TONIGHT WITH
CLOUD LAYERS GENERALLY SCT-BKN050-060 BKN-OVC080-100. SURFACE WINDS
WILL REMAIN SOUTHERLY 5-10 KT. KAM

&&

.MARINE...A SMALL WEAK SURFACE RIDGE WILL REMAIN OVER WESTERN
WASHINGTON THROUGH MONDAY MORNING. LOWER PRESSURE WILL CONTINUE OVER
BRITISH COLUMBIA AND THE WATERS OFFSHORE WHERE A BAROCLINIC ZONE
EXTENDS SOUTHWESTWARD FROM VANCOUVER ISLAND. THIS PATTERN WILL
RESULT IN MODERATE S FLOW ACROSS THE COASTAL WATERS THROUGH TONIGHT.
S FLOW OVER THE INLAND WATERS IS EXPECTED TO WEAKEN BELOW ADVISORY
CRITERIA THIS AFTERNOON.

AN APPROACHING COLD FRONT WILL INCREASE WINDS OVER THE COASTAL
WATERS ON MONDAY...AND BACK TO ADVISORY LEVELS OVER THE INLAND
WATERS. THE COLD FRONT IS EXPECTED TO CROSS THE COAST LATE MONDAY
AFTERNOON AND THE INLAND WATERS MONDAY EVENING. MODERATE TO STRONG
WESTERLY ONSHORE FLOW WILL DEVELOP OVER W WA MONDAY NIGHT BEHIND THE
COLD FRONT. GALE FORCE WINDS ARE LIKELY IN THE CENTRAL AND E STRAIT
OF JUAN DE FUCA MONDAY NIGHT AND TUESDAY...AND SCA WINDS ARE
EXPECTED OVER THE COASTAL WATERS AND THE WATERS ADJACENT TO THE
STRAIT.

THERE WILL BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS THROUGH TUESDAY...WITH ROUGH BAR CONDITIONS AS WELL.

ONSHORE FLOW WILL WEAKEN TUESDAY NIGHT AS A WEAK RIDGE TRIES TO
BUILD OVER THE AREA. HOWEVER THE GFS NOW SHOWS AN UPPER LEVEL
SHORTWAVE TROUGH CROSSING THE REGION WEDNESDAY. THIS FEATURE MAY
CAUSE ANOTHER BRIEF PERIOD OF MODERATE ONSHORE FLOW WEDNESDAY NIGHT.
KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.
     GALE WATCH FOR MONDAY NIGHT AND TUESDAY CENTRAL STRAIT AND
     EAST ENTRANCE STRAIT.

&&

$$

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













000
FXUS66 KSEW 291608
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 AM PDT SUN MAR 29 2015

.SYNOPSIS...A STALLED FRONTAL BOUNDARY WILL BRING SOME LIGHT RAIN AT
TIMES TO THE COAST AND NORTH INTERIOR THROUGH MONDAY. THE FRONT WILL
PUSH INLAND MONDAY NIGHT BRINGING RAIN TO THE REST OF THE AREA. A
TROUGH OF LOW PRESSURE WILL MOVE INTO THE REGION TUESDAY THROUGH THE
END OF NEXT WEEK. THE UPPER TROUGH WILL GIVE COOL AND SHOWERY
WEATHER TO THE AREA AND SNOW LEVELS WILL FALL TO AROUND 3000 FEET IN
THE MOUNTAINS TUESDAY NIGHT OR WEDNESDAY.

&&

.SHORT TERM...RADAR SHOWS WARM ADVECTION RAIN EXTENDING FROM THE N
WA COAST ACROSS THE N INTERIOR OF WRN WA THIS MORNING. EVERETT
REPORTED SOME OFF AND ON SPRINKLES EARLIER AND IT HAS STAYED DRY TO
THE S. THE GFS/NAM-12 APPEAR TO BE PERFORMING WELL AND KEEP QPF
LIMITED TO THE FAR NRN PART OF WRN WA THROUGH MONDAY. ELSEWHERE...IT
WILL BE PARTLY TO MOSTLY CLOUDY WITH HIGHS ABOVE AVERAGE IN THE LOW
TO MID 60S.

AN UPPER TROUGH WILL DIG SWD TOWARD THE PAC NW MONDAY AFTERNOON AS A
1000 MB SURFACE LOW TRACKS INTO CENTRAL BRITISH COLUMBIA. THE
ASSOCIATED COLD FRONT WILL BRING RAIN TO THE COAST BY THE
EVENING...THEN QUICKLY SPREADING INLAND. MODELS DEPICT A RATHER
VIGOROUS SYSTEM WITH MUCH COOLER AIR BEHIND THE FRONT. SNOW LEVELS
AHEAD OF THE FRONT WILL BE AROUND 6000 TO 7000 FEET...THEN FALLING
TO NEAR 3000 FEET BY LATER MONDAY NIGHT AND TUESDAY. STRONG ONSHORE
FLOW AND AN UNSTABLE AIR MASS WILL KEEP SHOWERS AND BREEZY
CONDITIONS GOING THROUGH TUESDAY AFTERNOON. THERE COULD EVEN BE SOME
ISOLATED THUNDERSTORMS GIVEN THE GFS40 FORECAST  LI`S OF -1 TO -2C.
WILL HOLD OFF MENTIONING THUNDER FOR NOW BUT WILL CONSIDER ADDING A
MENTION IN THE NEXT FORECAST PACKAGE. HIGH TEMPERATURES WILL BE
NOTICEABLY COOLER...ONLY IN THE MID 50S TUESDAY. AS FOR THE
MOUNTAINS...THE WRN SLOPES OF THE CASCADES SHOULD PICK UP SEVERAL
INCHES OF SNOW GIVEN SOME ADDED OROGRAPHIC ENHANCEMENT. BECAUSE OF
THE SHOWERY PATTERN IT MAY BE TOUGH TO GET SOLID ADVISORY LEVEL
AMOUNTS OF SNOW. THE EXCEPTION MIGHT BE THE CASCADES NEAR STEVENS
PASS WHERE A CONVERGENCE ZONE MAY FORM. MESO MODELS ARE SHOWING A
HEAVIER QPF BULLSEYE AROUND THE S SNOHOMISH/N KING COUNTY CASCADES
NEAR STEVENS PASS. SOMETHING TO CONSIDER ONCE WE GET CLOSER TO THE
EVENT. MERCER

.LONG TERM...FROM PREVIOUS DISCUSSION...AN UPPER LEVEL TROUGH WILL
GIVE COOL AND SHOWERY WEATHER TO THE AREA ON WEDNESDAY. THURSDAY MAY
SEE SOME DECREASE IN SHOWER ACTIVITY AND A LITTLE MORE SUNSHINE AS A
SHORT WAVE RIDGE MOVES THROUGH THE REGION.

BOTH THE ECMWF AND GFS MODELS SHOW COOL AND SHOWERY CONDITIONS
FRIDAY THROUGH NEXT WEEKEND WITH SNOW LEVELS 2500 TO 3000 FEET IN
THE MOUNTAINS. ENSEMBLES ARE RATHER CONSISTENT IN SHOWING THE CHANGE
TO THE COOLER WEATHER PATTERN WITH AN UPPER TROUGH OVER WESTERN
WASHINGTON. ALBRECHT

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A BROAD FLAT UPPER LEVEL RIDGE OVER THE PACIFIC
NORTHWEST WILL MAINTAIN FAIRLY MOIST WESTERLY FLOW ALOFT OVER W WA
THROUGH MONDAY MORNING. A NEARLY STATIONARY FRONT IS DRAPED ACROSS
SOUTHERN B.C. AND EXTENDS SW FROM VANCOUVER ISLAND ACROSS THE
OFFSHORE WATERS. THE FRONT WILL CONTINUE TO BRING A LITTLE LIGHT
RAIN AT TIMES ACROSS THE FAR N PART OF W WA...FROM KUIL TO KCLM TO
KBLI.

VFR CONDITIONS ARE EXPECTED TO CONTINUE OVER THE INTERIOR WITH CIGS
GENERALLY BKN050-060 WITH HIGHER OVC LAYERS. CIGS WILL PROBABLY BE A
LITTLE LOWER OVER THE N INTERIOR. MVFR CIGS ARE EXPECTED ON THE
COAST WITH POSSIBLE IFR CONDITIONS OVER THE N COAST CLOSER TO THE
STATIONARY FRONT.

A COLD FRONT WILL APPROACH THE AREA MONDAY...CROSSING THE COAST LATE
MONDAY AFTERNOON AND THE INTERIOR MONDAY EVENING.

KSEA...VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH TONIGHT WITH
CLOUD LAYERS GENERALLY SCT-BKN050-060 BKN-OVC080-100. SURFACE WINDS
WILL REMAIN SOUTHERLY 5-10 KT. KAM

&&

.MARINE...A SMALL WEAK SURFACE RIDGE WILL REMAIN OVER WESTERN
WASHINGTON THROUGH MONDAY MORNING. LOWER PRESSURE WILL CONTINUE OVER
BRITISH COLUMBIA AND THE WATERS OFFSHORE WHERE A BAROCLINIC ZONE
EXTENDS SOUTHWESTWARD FROM VANCOUVER ISLAND. THIS PATTERN WILL
RESULT IN MODERATE S FLOW ACROSS THE COASTAL WATERS THROUGH TONIGHT.
S FLOW OVER THE INLAND WATERS IS EXPECTED TO WEAKEN BELOW ADVISORY
CRITERIA THIS AFTERNOON.

AN APPROACHING COLD FRONT WILL INCREASE WINDS OVER THE COASTAL
WATERS ON MONDAY...AND BACK TO ADVISORY LEVELS OVER THE INLAND
WATERS. THE COLD FRONT IS EXPECTED TO CROSS THE COAST LATE MONDAY
AFTERNOON AND THE INLAND WATERS MONDAY EVENING. MODERATE TO STRONG
WESTERLY ONSHORE FLOW WILL DEVELOP OVER W WA MONDAY NIGHT BEHIND THE
COLD FRONT. GALE FORCE WINDS ARE LIKELY IN THE CENTRAL AND E STRAIT
OF JUAN DE FUCA MONDAY NIGHT AND TUESDAY...AND SCA WINDS ARE
EXPECTED OVER THE COASTAL WATERS AND THE WATERS ADJACENT TO THE
STRAIT.

THERE WILL BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS THROUGH TUESDAY...WITH ROUGH BAR CONDITIONS AS WELL.

ONSHORE FLOW WILL WEAKEN TUESDAY NIGHT AS A WEAK RIDGE TRIES TO
BUILD OVER THE AREA. HOWEVER THE GFS NOW SHOWS AN UPPER LEVEL
SHORTWAVE TROUGH CROSSING THE REGION WEDNESDAY. THIS FEATURE MAY
CAUSE ANOTHER BRIEF PERIOD OF MODERATE ONSHORE FLOW WEDNESDAY NIGHT.
KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.
     GALE WATCH FOR MONDAY NIGHT AND TUESDAY CENTRAL STRAIT AND
     EAST ENTRANCE STRAIT.

&&

$$

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












000
FXUS66 KSEW 291608
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 AM PDT SUN MAR 29 2015

.SYNOPSIS...A STALLED FRONTAL BOUNDARY WILL BRING SOME LIGHT RAIN AT
TIMES TO THE COAST AND NORTH INTERIOR THROUGH MONDAY. THE FRONT WILL
PUSH INLAND MONDAY NIGHT BRINGING RAIN TO THE REST OF THE AREA. A
TROUGH OF LOW PRESSURE WILL MOVE INTO THE REGION TUESDAY THROUGH THE
END OF NEXT WEEK. THE UPPER TROUGH WILL GIVE COOL AND SHOWERY
WEATHER TO THE AREA AND SNOW LEVELS WILL FALL TO AROUND 3000 FEET IN
THE MOUNTAINS TUESDAY NIGHT OR WEDNESDAY.

&&

.SHORT TERM...RADAR SHOWS WARM ADVECTION RAIN EXTENDING FROM THE N
WA COAST ACROSS THE N INTERIOR OF WRN WA THIS MORNING. EVERETT
REPORTED SOME OFF AND ON SPRINKLES EARLIER AND IT HAS STAYED DRY TO
THE S. THE GFS/NAM-12 APPEAR TO BE PERFORMING WELL AND KEEP QPF
LIMITED TO THE FAR NRN PART OF WRN WA THROUGH MONDAY. ELSEWHERE...IT
WILL BE PARTLY TO MOSTLY CLOUDY WITH HIGHS ABOVE AVERAGE IN THE LOW
TO MID 60S.

AN UPPER TROUGH WILL DIG SWD TOWARD THE PAC NW MONDAY AFTERNOON AS A
1000 MB SURFACE LOW TRACKS INTO CENTRAL BRITISH COLUMBIA. THE
ASSOCIATED COLD FRONT WILL BRING RAIN TO THE COAST BY THE
EVENING...THEN QUICKLY SPREADING INLAND. MODELS DEPICT A RATHER
VIGOROUS SYSTEM WITH MUCH COOLER AIR BEHIND THE FRONT. SNOW LEVELS
AHEAD OF THE FRONT WILL BE AROUND 6000 TO 7000 FEET...THEN FALLING
TO NEAR 3000 FEET BY LATER MONDAY NIGHT AND TUESDAY. STRONG ONSHORE
FLOW AND AN UNSTABLE AIR MASS WILL KEEP SHOWERS AND BREEZY
CONDITIONS GOING THROUGH TUESDAY AFTERNOON. THERE COULD EVEN BE SOME
ISOLATED THUNDERSTORMS GIVEN THE GFS40 FORECAST  LI`S OF -1 TO -2C.
WILL HOLD OFF MENTIONING THUNDER FOR NOW BUT WILL CONSIDER ADDING A
MENTION IN THE NEXT FORECAST PACKAGE. HIGH TEMPERATURES WILL BE
NOTICEABLY COOLER...ONLY IN THE MID 50S TUESDAY. AS FOR THE
MOUNTAINS...THE WRN SLOPES OF THE CASCADES SHOULD PICK UP SEVERAL
INCHES OF SNOW GIVEN SOME ADDED OROGRAPHIC ENHANCEMENT. BECAUSE OF
THE SHOWERY PATTERN IT MAY BE TOUGH TO GET SOLID ADVISORY LEVEL
AMOUNTS OF SNOW. THE EXCEPTION MIGHT BE THE CASCADES NEAR STEVENS
PASS WHERE A CONVERGENCE ZONE MAY FORM. MESO MODELS ARE SHOWING A
HEAVIER QPF BULLSEYE AROUND THE S SNOHOMISH/N KING COUNTY CASCADES
NEAR STEVENS PASS. SOMETHING TO CONSIDER ONCE WE GET CLOSER TO THE
EVENT. MERCER

.LONG TERM...FROM PREVIOUS DISCUSSION...AN UPPER LEVEL TROUGH WILL
GIVE COOL AND SHOWERY WEATHER TO THE AREA ON WEDNESDAY. THURSDAY MAY
SEE SOME DECREASE IN SHOWER ACTIVITY AND A LITTLE MORE SUNSHINE AS A
SHORT WAVE RIDGE MOVES THROUGH THE REGION.

BOTH THE ECMWF AND GFS MODELS SHOW COOL AND SHOWERY CONDITIONS
FRIDAY THROUGH NEXT WEEKEND WITH SNOW LEVELS 2500 TO 3000 FEET IN
THE MOUNTAINS. ENSEMBLES ARE RATHER CONSISTENT IN SHOWING THE CHANGE
TO THE COOLER WEATHER PATTERN WITH AN UPPER TROUGH OVER WESTERN
WASHINGTON. ALBRECHT

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A BROAD FLAT UPPER LEVEL RIDGE OVER THE PACIFIC
NORTHWEST WILL MAINTAIN FAIRLY MOIST WESTERLY FLOW ALOFT OVER W WA
THROUGH MONDAY MORNING. A NEARLY STATIONARY FRONT IS DRAPED ACROSS
SOUTHERN B.C. AND EXTENDS SW FROM VANCOUVER ISLAND ACROSS THE
OFFSHORE WATERS. THE FRONT WILL CONTINUE TO BRING A LITTLE LIGHT
RAIN AT TIMES ACROSS THE FAR N PART OF W WA...FROM KUIL TO KCLM TO
KBLI.

VFR CONDITIONS ARE EXPECTED TO CONTINUE OVER THE INTERIOR WITH CIGS
GENERALLY BKN050-060 WITH HIGHER OVC LAYERS. CIGS WILL PROBABLY BE A
LITTLE LOWER OVER THE N INTERIOR. MVFR CIGS ARE EXPECTED ON THE
COAST WITH POSSIBLE IFR CONDITIONS OVER THE N COAST CLOSER TO THE
STATIONARY FRONT.

A COLD FRONT WILL APPROACH THE AREA MONDAY...CROSSING THE COAST LATE
MONDAY AFTERNOON AND THE INTERIOR MONDAY EVENING.

KSEA...VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH TONIGHT WITH
CLOUD LAYERS GENERALLY SCT-BKN050-060 BKN-OVC080-100. SURFACE WINDS
WILL REMAIN SOUTHERLY 5-10 KT. KAM

&&

.MARINE...A SMALL WEAK SURFACE RIDGE WILL REMAIN OVER WESTERN
WASHINGTON THROUGH MONDAY MORNING. LOWER PRESSURE WILL CONTINUE OVER
BRITISH COLUMBIA AND THE WATERS OFFSHORE WHERE A BAROCLINIC ZONE
EXTENDS SOUTHWESTWARD FROM VANCOUVER ISLAND. THIS PATTERN WILL
RESULT IN MODERATE S FLOW ACROSS THE COASTAL WATERS THROUGH TONIGHT.
S FLOW OVER THE INLAND WATERS IS EXPECTED TO WEAKEN BELOW ADVISORY
CRITERIA THIS AFTERNOON.

AN APPROACHING COLD FRONT WILL INCREASE WINDS OVER THE COASTAL
WATERS ON MONDAY...AND BACK TO ADVISORY LEVELS OVER THE INLAND
WATERS. THE COLD FRONT IS EXPECTED TO CROSS THE COAST LATE MONDAY
AFTERNOON AND THE INLAND WATERS MONDAY EVENING. MODERATE TO STRONG
WESTERLY ONSHORE FLOW WILL DEVELOP OVER W WA MONDAY NIGHT BEHIND THE
COLD FRONT. GALE FORCE WINDS ARE LIKELY IN THE CENTRAL AND E STRAIT
OF JUAN DE FUCA MONDAY NIGHT AND TUESDAY...AND SCA WINDS ARE
EXPECTED OVER THE COASTAL WATERS AND THE WATERS ADJACENT TO THE
STRAIT.

THERE WILL BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS THROUGH TUESDAY...WITH ROUGH BAR CONDITIONS AS WELL.

ONSHORE FLOW WILL WEAKEN TUESDAY NIGHT AS A WEAK RIDGE TRIES TO
BUILD OVER THE AREA. HOWEVER THE GFS NOW SHOWS AN UPPER LEVEL
SHORTWAVE TROUGH CROSSING THE REGION WEDNESDAY. THIS FEATURE MAY
CAUSE ANOTHER BRIEF PERIOD OF MODERATE ONSHORE FLOW WEDNESDAY NIGHT.
KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.
     GALE WATCH FOR MONDAY NIGHT AND TUESDAY CENTRAL STRAIT AND
     EAST ENTRANCE STRAIT.

&&

$$

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













000
FXUS66 KSEW 291608
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 AM PDT SUN MAR 29 2015

.SYNOPSIS...A STALLED FRONTAL BOUNDARY WILL BRING SOME LIGHT RAIN AT
TIMES TO THE COAST AND NORTH INTERIOR THROUGH MONDAY. THE FRONT WILL
PUSH INLAND MONDAY NIGHT BRINGING RAIN TO THE REST OF THE AREA. A
TROUGH OF LOW PRESSURE WILL MOVE INTO THE REGION TUESDAY THROUGH THE
END OF NEXT WEEK. THE UPPER TROUGH WILL GIVE COOL AND SHOWERY
WEATHER TO THE AREA AND SNOW LEVELS WILL FALL TO AROUND 3000 FEET IN
THE MOUNTAINS TUESDAY NIGHT OR WEDNESDAY.

&&

.SHORT TERM...RADAR SHOWS WARM ADVECTION RAIN EXTENDING FROM THE N
WA COAST ACROSS THE N INTERIOR OF WRN WA THIS MORNING. EVERETT
REPORTED SOME OFF AND ON SPRINKLES EARLIER AND IT HAS STAYED DRY TO
THE S. THE GFS/NAM-12 APPEAR TO BE PERFORMING WELL AND KEEP QPF
LIMITED TO THE FAR NRN PART OF WRN WA THROUGH MONDAY. ELSEWHERE...IT
WILL BE PARTLY TO MOSTLY CLOUDY WITH HIGHS ABOVE AVERAGE IN THE LOW
TO MID 60S.

AN UPPER TROUGH WILL DIG SWD TOWARD THE PAC NW MONDAY AFTERNOON AS A
1000 MB SURFACE LOW TRACKS INTO CENTRAL BRITISH COLUMBIA. THE
ASSOCIATED COLD FRONT WILL BRING RAIN TO THE COAST BY THE
EVENING...THEN QUICKLY SPREADING INLAND. MODELS DEPICT A RATHER
VIGOROUS SYSTEM WITH MUCH COOLER AIR BEHIND THE FRONT. SNOW LEVELS
AHEAD OF THE FRONT WILL BE AROUND 6000 TO 7000 FEET...THEN FALLING
TO NEAR 3000 FEET BY LATER MONDAY NIGHT AND TUESDAY. STRONG ONSHORE
FLOW AND AN UNSTABLE AIR MASS WILL KEEP SHOWERS AND BREEZY
CONDITIONS GOING THROUGH TUESDAY AFTERNOON. THERE COULD EVEN BE SOME
ISOLATED THUNDERSTORMS GIVEN THE GFS40 FORECAST  LI`S OF -1 TO -2C.
WILL HOLD OFF MENTIONING THUNDER FOR NOW BUT WILL CONSIDER ADDING A
MENTION IN THE NEXT FORECAST PACKAGE. HIGH TEMPERATURES WILL BE
NOTICEABLY COOLER...ONLY IN THE MID 50S TUESDAY. AS FOR THE
MOUNTAINS...THE WRN SLOPES OF THE CASCADES SHOULD PICK UP SEVERAL
INCHES OF SNOW GIVEN SOME ADDED OROGRAPHIC ENHANCEMENT. BECAUSE OF
THE SHOWERY PATTERN IT MAY BE TOUGH TO GET SOLID ADVISORY LEVEL
AMOUNTS OF SNOW. THE EXCEPTION MIGHT BE THE CASCADES NEAR STEVENS
PASS WHERE A CONVERGENCE ZONE MAY FORM. MESO MODELS ARE SHOWING A
HEAVIER QPF BULLSEYE AROUND THE S SNOHOMISH/N KING COUNTY CASCADES
NEAR STEVENS PASS. SOMETHING TO CONSIDER ONCE WE GET CLOSER TO THE
EVENT. MERCER

.LONG TERM...FROM PREVIOUS DISCUSSION...AN UPPER LEVEL TROUGH WILL
GIVE COOL AND SHOWERY WEATHER TO THE AREA ON WEDNESDAY. THURSDAY MAY
SEE SOME DECREASE IN SHOWER ACTIVITY AND A LITTLE MORE SUNSHINE AS A
SHORT WAVE RIDGE MOVES THROUGH THE REGION.

BOTH THE ECMWF AND GFS MODELS SHOW COOL AND SHOWERY CONDITIONS
FRIDAY THROUGH NEXT WEEKEND WITH SNOW LEVELS 2500 TO 3000 FEET IN
THE MOUNTAINS. ENSEMBLES ARE RATHER CONSISTENT IN SHOWING THE CHANGE
TO THE COOLER WEATHER PATTERN WITH AN UPPER TROUGH OVER WESTERN
WASHINGTON. ALBRECHT

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A BROAD FLAT UPPER LEVEL RIDGE OVER THE PACIFIC
NORTHWEST WILL MAINTAIN FAIRLY MOIST WESTERLY FLOW ALOFT OVER W WA
THROUGH MONDAY MORNING. A NEARLY STATIONARY FRONT IS DRAPED ACROSS
SOUTHERN B.C. AND EXTENDS SW FROM VANCOUVER ISLAND ACROSS THE
OFFSHORE WATERS. THE FRONT WILL CONTINUE TO BRING A LITTLE LIGHT
RAIN AT TIMES ACROSS THE FAR N PART OF W WA...FROM KUIL TO KCLM TO
KBLI.

VFR CONDITIONS ARE EXPECTED TO CONTINUE OVER THE INTERIOR WITH CIGS
GENERALLY BKN050-060 WITH HIGHER OVC LAYERS. CIGS WILL PROBABLY BE A
LITTLE LOWER OVER THE N INTERIOR. MVFR CIGS ARE EXPECTED ON THE
COAST WITH POSSIBLE IFR CONDITIONS OVER THE N COAST CLOSER TO THE
STATIONARY FRONT.

A COLD FRONT WILL APPROACH THE AREA MONDAY...CROSSING THE COAST LATE
MONDAY AFTERNOON AND THE INTERIOR MONDAY EVENING.

KSEA...VFR CONDITIONS ARE EXPECTED TO CONTINUE THROUGH TONIGHT WITH
CLOUD LAYERS GENERALLY SCT-BKN050-060 BKN-OVC080-100. SURFACE WINDS
WILL REMAIN SOUTHERLY 5-10 KT. KAM

&&

.MARINE...A SMALL WEAK SURFACE RIDGE WILL REMAIN OVER WESTERN
WASHINGTON THROUGH MONDAY MORNING. LOWER PRESSURE WILL CONTINUE OVER
BRITISH COLUMBIA AND THE WATERS OFFSHORE WHERE A BAROCLINIC ZONE
EXTENDS SOUTHWESTWARD FROM VANCOUVER ISLAND. THIS PATTERN WILL
RESULT IN MODERATE S FLOW ACROSS THE COASTAL WATERS THROUGH TONIGHT.
S FLOW OVER THE INLAND WATERS IS EXPECTED TO WEAKEN BELOW ADVISORY
CRITERIA THIS AFTERNOON.

AN APPROACHING COLD FRONT WILL INCREASE WINDS OVER THE COASTAL
WATERS ON MONDAY...AND BACK TO ADVISORY LEVELS OVER THE INLAND
WATERS. THE COLD FRONT IS EXPECTED TO CROSS THE COAST LATE MONDAY
AFTERNOON AND THE INLAND WATERS MONDAY EVENING. MODERATE TO STRONG
WESTERLY ONSHORE FLOW WILL DEVELOP OVER W WA MONDAY NIGHT BEHIND THE
COLD FRONT. GALE FORCE WINDS ARE LIKELY IN THE CENTRAL AND E STRAIT
OF JUAN DE FUCA MONDAY NIGHT AND TUESDAY...AND SCA WINDS ARE
EXPECTED OVER THE COASTAL WATERS AND THE WATERS ADJACENT TO THE
STRAIT.

THERE WILL BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS THROUGH TUESDAY...WITH ROUGH BAR CONDITIONS AS WELL.

ONSHORE FLOW WILL WEAKEN TUESDAY NIGHT AS A WEAK RIDGE TRIES TO
BUILD OVER THE AREA. HOWEVER THE GFS NOW SHOWS AN UPPER LEVEL
SHORTWAVE TROUGH CROSSING THE REGION WEDNESDAY. THIS FEATURE MAY
CAUSE ANOTHER BRIEF PERIOD OF MODERATE ONSHORE FLOW WEDNESDAY NIGHT.
KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.
     GALE WATCH FOR MONDAY NIGHT AND TUESDAY CENTRAL STRAIT AND
     EAST ENTRANCE STRAIT.

&&

$$

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












000
FXUS66 KSEW 290921
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
220 AM PDT SUN MAR 29 2015

.SYNOPSIS...A STALLED FRONTAL BOUNDARY WILL BRING SOME LIGHT RAIN AT
TIMES TO THE COAST AND NORTH INTERIOR THROUGH MONDAY. THE FRONT WILL
PUSH INLAND MONDAY NIGHT BRINGING RAIN TO THE REST OF THE AREA. A
TROUGH OF LOW PRESSURE WILL MOVE INTO THE REGION TUESDAY THROUGH THE
END OF NEXT WEEK. THE UPPER TROUGH WILL GIVE COOL AND SHOWERY
WEATHER TO THE AREA AND SNOW LEVELS WILL FALL TO AROUND 3000 FEET IN
THE MOUNTAINS TUESDAY NIGHT OR WEDNESDAY.

&&

.SHORT TERM...A WEAK RIDGE OF HIGH PRESSURE ALOFT IS CENTERED OVER
EASTERN WASHINGTON EARLY THIS MORNING WHILE A SURFACE HIGH IS
CENTERED OVER THE INTERIOR OF WESTERN WASHINGTON. IN THE MEAN
TIME...A SERIES OF WEAK WARM FRONTAL FEATURES ARE LIFTING
NORTHEASTWARD ACROSS THE OFFSHORE AND COASTAL WATERS INTO VANCOUVER
ISLAND. THE WARM ADVECTION AND SOUTHERLY FLOW AT THE LOWER LEVELS IS
GIVING SOME RAIN TO THE NORTH COAST...AND LIGHT RAIN OR SPRINKLES
ARE OCCASIONALLY MAKING IT ONTO THE CENTRAL COAST AND INTO THE
INTERIOR FROM ABOUT WHIDBEY ISLAND NORTH AND WEST. SATELLITE AND
RADAR LOOPS HINT THAT THE LIGHT PRECIPITATION MAY MAKE IT SOUTH AND
EAST AS FAR AS AN EVERETT TO SHELTON LINE THIS MORNING BEFORE IT
LIFTS BACK TO THE NORTH.

A WAVE OF LOW PRESSURE DEVELOPING AROUND 40N 140W LATER THIS MORNING
WILL MOVE TO THE QUEEN CHARLOTTE SOUND AS A 1004 MB LOW TONIGHT AND
EARLY MONDAY. THE WARM ADVECTION TO THE EAST OF THIS DEVELOPING
FEATURE WILL HAVE THE EFFECT OF BUILDING THE RIDGE SOMEWHAT OVER THE
INTERIOR OF WESTERN WASHINGTON...KEEPING CONDITIONS IN THE INTERIOR
FROM ABOUT EVERETT SOUTHWARD DRY. THE COAST AND THE CHEHALIS GAP
AREA WILL CONTINUE TO SEE A CHANCE OF LIGHT RAIN AT TIMES AS WARM
FRONTAL FEATURES CLIP THE COASTLINE.

TEMPERATURES TODAY THROUGH MONDAY WILL BE MILD FOR LATE MARCH WITH
HIGHS 55-65 AND LOWS AROUND THE 50 DEGREE MARK.

SHORT TERM MODELS ARE CONSISTENT IN SHOWING THE FRONT FINALLY
SURGING EASTWARD THROUGH THE INTERIOR OF WESTERN WASHINGTON ON
MONDAY NIGHT. RAIN MONDAY EVENING WILL CHANGE TO SHOWERS LATE IN THE
NIGHT BEHIND THE FRONT...AND INCREASING WEST TO SOUTHWEST GRADIENTS
WILL GIVE ONSHORE FLOW AND BREEZY TO WINDY CONDITIONS AROUND THE
EASTERN STRAIT OF JUAN DE FUCA. TEMPERATURES IN THE LOWLANDS WILL
COOL INTO THE 40S TO LOWER 50S TUESDAY BEHIND THE FRONT AND A
CONVERGENCE ZONE WILL LIKELY DEVELOP LATER MONDAY NIGHT INTO TUESDAY
AS FLOW ALOFT INTERACTS WITH THE OLYMPICS. 500 MB HEIGHTS FALL OFF
TO 545 DAM MIDDAY TUESDAY AND 850 MB TEMPERATURES DROP TO AROUND -2C
TO -3C. SNOW LEVELS WILL LIKELY FALL TO 3000-4000 FEET ON TUESDAY.
IT IS POSSIBLE THAT A WINTER WEATHER ADVISORY WILL BE NEEDED AT SOME
POINT ON TUESDAY IN THE CENTRAL CASCADES WHERE THE PUGET SOUND
CONVERGENCE ZONE SETS UP...BUT IT IS TOO EARLY TO PINPOINT WHERE
THIS WOULD OCCUR AT THIS TIME. ALBRECHT

.LONG TERM...AN UPPER LEVEL TROUGH WILL GIVE COOL AND SHOWERY
WEATHER TO THE AREA ON WEDNESDAY. THURSDAY MAY SEE SOME DECREASE IN
SHOWER ACTIVITY AND A LITTLE MORE SUNSHINE AS A SHORT WAVE RIDGE
MOVES THROUGH THE REGION.

BOTH THE ECMWF AND GFS MODELS SHOW COOL AND SHOWERY CONDITIONS
FRIDAY THROUGH NEXT WEEKEND WITH SNOW LEVELS 2500 TO 3000 FEET IN
THE MOUNTAINS. ENSEMBLES ARE RATHER CONSISTENT IN SHOWING THE CHANGE
TO THE COOLER WEATHER PATTERN WITH AN UPPER TROUGH OVER WESTERN
WASHINGTON. ALBRECHT

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT OVER WESTERN WASHINGTON EARLY THIS
MORNING WILL BACK SLIGHTLY TO SOUTHWEST TONIGHT...AS THE FLAT UPPER
RIDGE OVER THE PACIFIC NORTHWEST MOVES SLOWLY EAST. A FRONT WILL
REMAIN ALONG THE NORTHWEST SIDE OF THE RIDGE...EXTENDING FROM
SOUTHERN BRITISH COLUMBIA SOUTHWEST INTO THE OFFSHORE WATERS. THE
AIR MASS WILL REMAIN FAIRLY MOIST...ESPECIALLY AT MIDDLE AND UPPER
LEVELS.

VFR CONDITIONS CONTINUE ACROSS THE FORECAST AREA EARLY THIS
MORNING...WITH SKY COVER ROUGHLY SCT-BKN040 BKN-060-075 AND HIGHER
BKN-OVC LAYERS ABOVE. AREAS OF LIGHT PRECIPITATION CONTINUE OVER THE
NORTH PART OF THE AREA. ON THE WHOLE THERE WILL BE LITTLE CHANGE
THROUGH TONIGHT.

KSEA...SOUTH OR SOUTHWEST WIND 6-12 KT. BKN-OVC CEILING COULD LOWER
TO AROUND 5000 FT TONIGHT BUT REMAIN VFR.   MCDONNAL

&&

.MARINE...A RIDGE WILL REMAIN OVER WESTERN WASHINGTON THROUGH
MONDAY... WHILE A FRONT EXTENDS FROM VANCOUVER ISLAND INTO THE
OFFSHORE WATERS. THE SOUTHERLY GRADIENT ASSOCIATED WITH THIS PATTERN
IS PRODUCING WINDS OF 15 TO 30 KT...WITH THE HIGHEST WINDS GENERALLY
IN THE NORTH PART OF THE FORECAST AREA.

A COLD FRONT WILL MOVE ACROSS THE COASTAL WATERS AND WESTERN
WASHINGTON LATE MONDAY AND MONDAY NIGHT...FOLLOWED BY STRONG ONSHORE
FLOW MONDAY NIGHT AND TUESDAY. THERE IS A GOOD CHANCE THAT GALE
WESTERLIES WILL OCCUR IN THE CENTRAL STRAIT OF JUAN DE FUCA AND EAST
ENTRANCE STRAIT LATER MONDAY NIGHT AND TUESDAY...AND A GALE WATCH IS
BEING ISSUED WITH THE EARLY MORNING FORECAST.

THERE WILL BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS THROUGH TUESDAY...WITH ROUGH BAR CONDITIONS AS WELL.

A WEAK RIDGE WILL BUILD OVER THE AREA WEDNESDAY AND THURSDAY.
MCDONNAL


&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.
     GALE WATCH FOR MONDAY NIGHT AND TUESDAY CENTRAL STRAIT
      AND EAST ENTRANCE STRAIT.

&&

$$

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










000
FXUS66 KSEW 290921
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
220 AM PDT SUN MAR 29 2015

.SYNOPSIS...A STALLED FRONTAL BOUNDARY WILL BRING SOME LIGHT RAIN AT
TIMES TO THE COAST AND NORTH INTERIOR THROUGH MONDAY. THE FRONT WILL
PUSH INLAND MONDAY NIGHT BRINGING RAIN TO THE REST OF THE AREA. A
TROUGH OF LOW PRESSURE WILL MOVE INTO THE REGION TUESDAY THROUGH THE
END OF NEXT WEEK. THE UPPER TROUGH WILL GIVE COOL AND SHOWERY
WEATHER TO THE AREA AND SNOW LEVELS WILL FALL TO AROUND 3000 FEET IN
THE MOUNTAINS TUESDAY NIGHT OR WEDNESDAY.

&&

.SHORT TERM...A WEAK RIDGE OF HIGH PRESSURE ALOFT IS CENTERED OVER
EASTERN WASHINGTON EARLY THIS MORNING WHILE A SURFACE HIGH IS
CENTERED OVER THE INTERIOR OF WESTERN WASHINGTON. IN THE MEAN
TIME...A SERIES OF WEAK WARM FRONTAL FEATURES ARE LIFTING
NORTHEASTWARD ACROSS THE OFFSHORE AND COASTAL WATERS INTO VANCOUVER
ISLAND. THE WARM ADVECTION AND SOUTHERLY FLOW AT THE LOWER LEVELS IS
GIVING SOME RAIN TO THE NORTH COAST...AND LIGHT RAIN OR SPRINKLES
ARE OCCASIONALLY MAKING IT ONTO THE CENTRAL COAST AND INTO THE
INTERIOR FROM ABOUT WHIDBEY ISLAND NORTH AND WEST. SATELLITE AND
RADAR LOOPS HINT THAT THE LIGHT PRECIPITATION MAY MAKE IT SOUTH AND
EAST AS FAR AS AN EVERETT TO SHELTON LINE THIS MORNING BEFORE IT
LIFTS BACK TO THE NORTH.

A WAVE OF LOW PRESSURE DEVELOPING AROUND 40N 140W LATER THIS MORNING
WILL MOVE TO THE QUEEN CHARLOTTE SOUND AS A 1004 MB LOW TONIGHT AND
EARLY MONDAY. THE WARM ADVECTION TO THE EAST OF THIS DEVELOPING
FEATURE WILL HAVE THE EFFECT OF BUILDING THE RIDGE SOMEWHAT OVER THE
INTERIOR OF WESTERN WASHINGTON...KEEPING CONDITIONS IN THE INTERIOR
FROM ABOUT EVERETT SOUTHWARD DRY. THE COAST AND THE CHEHALIS GAP
AREA WILL CONTINUE TO SEE A CHANCE OF LIGHT RAIN AT TIMES AS WARM
FRONTAL FEATURES CLIP THE COASTLINE.

TEMPERATURES TODAY THROUGH MONDAY WILL BE MILD FOR LATE MARCH WITH
HIGHS 55-65 AND LOWS AROUND THE 50 DEGREE MARK.

SHORT TERM MODELS ARE CONSISTENT IN SHOWING THE FRONT FINALLY
SURGING EASTWARD THROUGH THE INTERIOR OF WESTERN WASHINGTON ON
MONDAY NIGHT. RAIN MONDAY EVENING WILL CHANGE TO SHOWERS LATE IN THE
NIGHT BEHIND THE FRONT...AND INCREASING WEST TO SOUTHWEST GRADIENTS
WILL GIVE ONSHORE FLOW AND BREEZY TO WINDY CONDITIONS AROUND THE
EASTERN STRAIT OF JUAN DE FUCA. TEMPERATURES IN THE LOWLANDS WILL
COOL INTO THE 40S TO LOWER 50S TUESDAY BEHIND THE FRONT AND A
CONVERGENCE ZONE WILL LIKELY DEVELOP LATER MONDAY NIGHT INTO TUESDAY
AS FLOW ALOFT INTERACTS WITH THE OLYMPICS. 500 MB HEIGHTS FALL OFF
TO 545 DAM MIDDAY TUESDAY AND 850 MB TEMPERATURES DROP TO AROUND -2C
TO -3C. SNOW LEVELS WILL LIKELY FALL TO 3000-4000 FEET ON TUESDAY.
IT IS POSSIBLE THAT A WINTER WEATHER ADVISORY WILL BE NEEDED AT SOME
POINT ON TUESDAY IN THE CENTRAL CASCADES WHERE THE PUGET SOUND
CONVERGENCE ZONE SETS UP...BUT IT IS TOO EARLY TO PINPOINT WHERE
THIS WOULD OCCUR AT THIS TIME. ALBRECHT

.LONG TERM...AN UPPER LEVEL TROUGH WILL GIVE COOL AND SHOWERY
WEATHER TO THE AREA ON WEDNESDAY. THURSDAY MAY SEE SOME DECREASE IN
SHOWER ACTIVITY AND A LITTLE MORE SUNSHINE AS A SHORT WAVE RIDGE
MOVES THROUGH THE REGION.

BOTH THE ECMWF AND GFS MODELS SHOW COOL AND SHOWERY CONDITIONS
FRIDAY THROUGH NEXT WEEKEND WITH SNOW LEVELS 2500 TO 3000 FEET IN
THE MOUNTAINS. ENSEMBLES ARE RATHER CONSISTENT IN SHOWING THE CHANGE
TO THE COOLER WEATHER PATTERN WITH AN UPPER TROUGH OVER WESTERN
WASHINGTON. ALBRECHT

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT OVER WESTERN WASHINGTON EARLY THIS
MORNING WILL BACK SLIGHTLY TO SOUTHWEST TONIGHT...AS THE FLAT UPPER
RIDGE OVER THE PACIFIC NORTHWEST MOVES SLOWLY EAST. A FRONT WILL
REMAIN ALONG THE NORTHWEST SIDE OF THE RIDGE...EXTENDING FROM
SOUTHERN BRITISH COLUMBIA SOUTHWEST INTO THE OFFSHORE WATERS. THE
AIR MASS WILL REMAIN FAIRLY MOIST...ESPECIALLY AT MIDDLE AND UPPER
LEVELS.

VFR CONDITIONS CONTINUE ACROSS THE FORECAST AREA EARLY THIS
MORNING...WITH SKY COVER ROUGHLY SCT-BKN040 BKN-060-075 AND HIGHER
BKN-OVC LAYERS ABOVE. AREAS OF LIGHT PRECIPITATION CONTINUE OVER THE
NORTH PART OF THE AREA. ON THE WHOLE THERE WILL BE LITTLE CHANGE
THROUGH TONIGHT.

KSEA...SOUTH OR SOUTHWEST WIND 6-12 KT. BKN-OVC CEILING COULD LOWER
TO AROUND 5000 FT TONIGHT BUT REMAIN VFR.   MCDONNAL

&&

.MARINE...A RIDGE WILL REMAIN OVER WESTERN WASHINGTON THROUGH
MONDAY... WHILE A FRONT EXTENDS FROM VANCOUVER ISLAND INTO THE
OFFSHORE WATERS. THE SOUTHERLY GRADIENT ASSOCIATED WITH THIS PATTERN
IS PRODUCING WINDS OF 15 TO 30 KT...WITH THE HIGHEST WINDS GENERALLY
IN THE NORTH PART OF THE FORECAST AREA.

A COLD FRONT WILL MOVE ACROSS THE COASTAL WATERS AND WESTERN
WASHINGTON LATE MONDAY AND MONDAY NIGHT...FOLLOWED BY STRONG ONSHORE
FLOW MONDAY NIGHT AND TUESDAY. THERE IS A GOOD CHANCE THAT GALE
WESTERLIES WILL OCCUR IN THE CENTRAL STRAIT OF JUAN DE FUCA AND EAST
ENTRANCE STRAIT LATER MONDAY NIGHT AND TUESDAY...AND A GALE WATCH IS
BEING ISSUED WITH THE EARLY MORNING FORECAST.

THERE WILL BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS THROUGH TUESDAY...WITH ROUGH BAR CONDITIONS AS WELL.

A WEAK RIDGE WILL BUILD OVER THE AREA WEDNESDAY AND THURSDAY.
MCDONNAL


&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.
     GALE WATCH FOR MONDAY NIGHT AND TUESDAY CENTRAL STRAIT
      AND EAST ENTRANCE STRAIT.

&&

$$

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









000
FXUS66 KSEW 290921
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
220 AM PDT SUN MAR 29 2015

.SYNOPSIS...A STALLED FRONTAL BOUNDARY WILL BRING SOME LIGHT RAIN AT
TIMES TO THE COAST AND NORTH INTERIOR THROUGH MONDAY. THE FRONT WILL
PUSH INLAND MONDAY NIGHT BRINGING RAIN TO THE REST OF THE AREA. A
TROUGH OF LOW PRESSURE WILL MOVE INTO THE REGION TUESDAY THROUGH THE
END OF NEXT WEEK. THE UPPER TROUGH WILL GIVE COOL AND SHOWERY
WEATHER TO THE AREA AND SNOW LEVELS WILL FALL TO AROUND 3000 FEET IN
THE MOUNTAINS TUESDAY NIGHT OR WEDNESDAY.

&&

.SHORT TERM...A WEAK RIDGE OF HIGH PRESSURE ALOFT IS CENTERED OVER
EASTERN WASHINGTON EARLY THIS MORNING WHILE A SURFACE HIGH IS
CENTERED OVER THE INTERIOR OF WESTERN WASHINGTON. IN THE MEAN
TIME...A SERIES OF WEAK WARM FRONTAL FEATURES ARE LIFTING
NORTHEASTWARD ACROSS THE OFFSHORE AND COASTAL WATERS INTO VANCOUVER
ISLAND. THE WARM ADVECTION AND SOUTHERLY FLOW AT THE LOWER LEVELS IS
GIVING SOME RAIN TO THE NORTH COAST...AND LIGHT RAIN OR SPRINKLES
ARE OCCASIONALLY MAKING IT ONTO THE CENTRAL COAST AND INTO THE
INTERIOR FROM ABOUT WHIDBEY ISLAND NORTH AND WEST. SATELLITE AND
RADAR LOOPS HINT THAT THE LIGHT PRECIPITATION MAY MAKE IT SOUTH AND
EAST AS FAR AS AN EVERETT TO SHELTON LINE THIS MORNING BEFORE IT
LIFTS BACK TO THE NORTH.

A WAVE OF LOW PRESSURE DEVELOPING AROUND 40N 140W LATER THIS MORNING
WILL MOVE TO THE QUEEN CHARLOTTE SOUND AS A 1004 MB LOW TONIGHT AND
EARLY MONDAY. THE WARM ADVECTION TO THE EAST OF THIS DEVELOPING
FEATURE WILL HAVE THE EFFECT OF BUILDING THE RIDGE SOMEWHAT OVER THE
INTERIOR OF WESTERN WASHINGTON...KEEPING CONDITIONS IN THE INTERIOR
FROM ABOUT EVERETT SOUTHWARD DRY. THE COAST AND THE CHEHALIS GAP
AREA WILL CONTINUE TO SEE A CHANCE OF LIGHT RAIN AT TIMES AS WARM
FRONTAL FEATURES CLIP THE COASTLINE.

TEMPERATURES TODAY THROUGH MONDAY WILL BE MILD FOR LATE MARCH WITH
HIGHS 55-65 AND LOWS AROUND THE 50 DEGREE MARK.

SHORT TERM MODELS ARE CONSISTENT IN SHOWING THE FRONT FINALLY
SURGING EASTWARD THROUGH THE INTERIOR OF WESTERN WASHINGTON ON
MONDAY NIGHT. RAIN MONDAY EVENING WILL CHANGE TO SHOWERS LATE IN THE
NIGHT BEHIND THE FRONT...AND INCREASING WEST TO SOUTHWEST GRADIENTS
WILL GIVE ONSHORE FLOW AND BREEZY TO WINDY CONDITIONS AROUND THE
EASTERN STRAIT OF JUAN DE FUCA. TEMPERATURES IN THE LOWLANDS WILL
COOL INTO THE 40S TO LOWER 50S TUESDAY BEHIND THE FRONT AND A
CONVERGENCE ZONE WILL LIKELY DEVELOP LATER MONDAY NIGHT INTO TUESDAY
AS FLOW ALOFT INTERACTS WITH THE OLYMPICS. 500 MB HEIGHTS FALL OFF
TO 545 DAM MIDDAY TUESDAY AND 850 MB TEMPERATURES DROP TO AROUND -2C
TO -3C. SNOW LEVELS WILL LIKELY FALL TO 3000-4000 FEET ON TUESDAY.
IT IS POSSIBLE THAT A WINTER WEATHER ADVISORY WILL BE NEEDED AT SOME
POINT ON TUESDAY IN THE CENTRAL CASCADES WHERE THE PUGET SOUND
CONVERGENCE ZONE SETS UP...BUT IT IS TOO EARLY TO PINPOINT WHERE
THIS WOULD OCCUR AT THIS TIME. ALBRECHT

.LONG TERM...AN UPPER LEVEL TROUGH WILL GIVE COOL AND SHOWERY
WEATHER TO THE AREA ON WEDNESDAY. THURSDAY MAY SEE SOME DECREASE IN
SHOWER ACTIVITY AND A LITTLE MORE SUNSHINE AS A SHORT WAVE RIDGE
MOVES THROUGH THE REGION.

BOTH THE ECMWF AND GFS MODELS SHOW COOL AND SHOWERY CONDITIONS
FRIDAY THROUGH NEXT WEEKEND WITH SNOW LEVELS 2500 TO 3000 FEET IN
THE MOUNTAINS. ENSEMBLES ARE RATHER CONSISTENT IN SHOWING THE CHANGE
TO THE COOLER WEATHER PATTERN WITH AN UPPER TROUGH OVER WESTERN
WASHINGTON. ALBRECHT

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT OVER WESTERN WASHINGTON EARLY THIS
MORNING WILL BACK SLIGHTLY TO SOUTHWEST TONIGHT...AS THE FLAT UPPER
RIDGE OVER THE PACIFIC NORTHWEST MOVES SLOWLY EAST. A FRONT WILL
REMAIN ALONG THE NORTHWEST SIDE OF THE RIDGE...EXTENDING FROM
SOUTHERN BRITISH COLUMBIA SOUTHWEST INTO THE OFFSHORE WATERS. THE
AIR MASS WILL REMAIN FAIRLY MOIST...ESPECIALLY AT MIDDLE AND UPPER
LEVELS.

VFR CONDITIONS CONTINUE ACROSS THE FORECAST AREA EARLY THIS
MORNING...WITH SKY COVER ROUGHLY SCT-BKN040 BKN-060-075 AND HIGHER
BKN-OVC LAYERS ABOVE. AREAS OF LIGHT PRECIPITATION CONTINUE OVER THE
NORTH PART OF THE AREA. ON THE WHOLE THERE WILL BE LITTLE CHANGE
THROUGH TONIGHT.

KSEA...SOUTH OR SOUTHWEST WIND 6-12 KT. BKN-OVC CEILING COULD LOWER
TO AROUND 5000 FT TONIGHT BUT REMAIN VFR.   MCDONNAL

&&

.MARINE...A RIDGE WILL REMAIN OVER WESTERN WASHINGTON THROUGH
MONDAY... WHILE A FRONT EXTENDS FROM VANCOUVER ISLAND INTO THE
OFFSHORE WATERS. THE SOUTHERLY GRADIENT ASSOCIATED WITH THIS PATTERN
IS PRODUCING WINDS OF 15 TO 30 KT...WITH THE HIGHEST WINDS GENERALLY
IN THE NORTH PART OF THE FORECAST AREA.

A COLD FRONT WILL MOVE ACROSS THE COASTAL WATERS AND WESTERN
WASHINGTON LATE MONDAY AND MONDAY NIGHT...FOLLOWED BY STRONG ONSHORE
FLOW MONDAY NIGHT AND TUESDAY. THERE IS A GOOD CHANCE THAT GALE
WESTERLIES WILL OCCUR IN THE CENTRAL STRAIT OF JUAN DE FUCA AND EAST
ENTRANCE STRAIT LATER MONDAY NIGHT AND TUESDAY...AND A GALE WATCH IS
BEING ISSUED WITH THE EARLY MORNING FORECAST.

THERE WILL BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS THROUGH TUESDAY...WITH ROUGH BAR CONDITIONS AS WELL.

A WEAK RIDGE WILL BUILD OVER THE AREA WEDNESDAY AND THURSDAY.
MCDONNAL


&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.
     GALE WATCH FOR MONDAY NIGHT AND TUESDAY CENTRAL STRAIT
      AND EAST ENTRANCE STRAIT.

&&

$$

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










000
FXUS66 KSEW 290921
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
220 AM PDT SUN MAR 29 2015

.SYNOPSIS...A STALLED FRONTAL BOUNDARY WILL BRING SOME LIGHT RAIN AT
TIMES TO THE COAST AND NORTH INTERIOR THROUGH MONDAY. THE FRONT WILL
PUSH INLAND MONDAY NIGHT BRINGING RAIN TO THE REST OF THE AREA. A
TROUGH OF LOW PRESSURE WILL MOVE INTO THE REGION TUESDAY THROUGH THE
END OF NEXT WEEK. THE UPPER TROUGH WILL GIVE COOL AND SHOWERY
WEATHER TO THE AREA AND SNOW LEVELS WILL FALL TO AROUND 3000 FEET IN
THE MOUNTAINS TUESDAY NIGHT OR WEDNESDAY.

&&

.SHORT TERM...A WEAK RIDGE OF HIGH PRESSURE ALOFT IS CENTERED OVER
EASTERN WASHINGTON EARLY THIS MORNING WHILE A SURFACE HIGH IS
CENTERED OVER THE INTERIOR OF WESTERN WASHINGTON. IN THE MEAN
TIME...A SERIES OF WEAK WARM FRONTAL FEATURES ARE LIFTING
NORTHEASTWARD ACROSS THE OFFSHORE AND COASTAL WATERS INTO VANCOUVER
ISLAND. THE WARM ADVECTION AND SOUTHERLY FLOW AT THE LOWER LEVELS IS
GIVING SOME RAIN TO THE NORTH COAST...AND LIGHT RAIN OR SPRINKLES
ARE OCCASIONALLY MAKING IT ONTO THE CENTRAL COAST AND INTO THE
INTERIOR FROM ABOUT WHIDBEY ISLAND NORTH AND WEST. SATELLITE AND
RADAR LOOPS HINT THAT THE LIGHT PRECIPITATION MAY MAKE IT SOUTH AND
EAST AS FAR AS AN EVERETT TO SHELTON LINE THIS MORNING BEFORE IT
LIFTS BACK TO THE NORTH.

A WAVE OF LOW PRESSURE DEVELOPING AROUND 40N 140W LATER THIS MORNING
WILL MOVE TO THE QUEEN CHARLOTTE SOUND AS A 1004 MB LOW TONIGHT AND
EARLY MONDAY. THE WARM ADVECTION TO THE EAST OF THIS DEVELOPING
FEATURE WILL HAVE THE EFFECT OF BUILDING THE RIDGE SOMEWHAT OVER THE
INTERIOR OF WESTERN WASHINGTON...KEEPING CONDITIONS IN THE INTERIOR
FROM ABOUT EVERETT SOUTHWARD DRY. THE COAST AND THE CHEHALIS GAP
AREA WILL CONTINUE TO SEE A CHANCE OF LIGHT RAIN AT TIMES AS WARM
FRONTAL FEATURES CLIP THE COASTLINE.

TEMPERATURES TODAY THROUGH MONDAY WILL BE MILD FOR LATE MARCH WITH
HIGHS 55-65 AND LOWS AROUND THE 50 DEGREE MARK.

SHORT TERM MODELS ARE CONSISTENT IN SHOWING THE FRONT FINALLY
SURGING EASTWARD THROUGH THE INTERIOR OF WESTERN WASHINGTON ON
MONDAY NIGHT. RAIN MONDAY EVENING WILL CHANGE TO SHOWERS LATE IN THE
NIGHT BEHIND THE FRONT...AND INCREASING WEST TO SOUTHWEST GRADIENTS
WILL GIVE ONSHORE FLOW AND BREEZY TO WINDY CONDITIONS AROUND THE
EASTERN STRAIT OF JUAN DE FUCA. TEMPERATURES IN THE LOWLANDS WILL
COOL INTO THE 40S TO LOWER 50S TUESDAY BEHIND THE FRONT AND A
CONVERGENCE ZONE WILL LIKELY DEVELOP LATER MONDAY NIGHT INTO TUESDAY
AS FLOW ALOFT INTERACTS WITH THE OLYMPICS. 500 MB HEIGHTS FALL OFF
TO 545 DAM MIDDAY TUESDAY AND 850 MB TEMPERATURES DROP TO AROUND -2C
TO -3C. SNOW LEVELS WILL LIKELY FALL TO 3000-4000 FEET ON TUESDAY.
IT IS POSSIBLE THAT A WINTER WEATHER ADVISORY WILL BE NEEDED AT SOME
POINT ON TUESDAY IN THE CENTRAL CASCADES WHERE THE PUGET SOUND
CONVERGENCE ZONE SETS UP...BUT IT IS TOO EARLY TO PINPOINT WHERE
THIS WOULD OCCUR AT THIS TIME. ALBRECHT

.LONG TERM...AN UPPER LEVEL TROUGH WILL GIVE COOL AND SHOWERY
WEATHER TO THE AREA ON WEDNESDAY. THURSDAY MAY SEE SOME DECREASE IN
SHOWER ACTIVITY AND A LITTLE MORE SUNSHINE AS A SHORT WAVE RIDGE
MOVES THROUGH THE REGION.

BOTH THE ECMWF AND GFS MODELS SHOW COOL AND SHOWERY CONDITIONS
FRIDAY THROUGH NEXT WEEKEND WITH SNOW LEVELS 2500 TO 3000 FEET IN
THE MOUNTAINS. ENSEMBLES ARE RATHER CONSISTENT IN SHOWING THE CHANGE
TO THE COOLER WEATHER PATTERN WITH AN UPPER TROUGH OVER WESTERN
WASHINGTON. ALBRECHT

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT OVER WESTERN WASHINGTON EARLY THIS
MORNING WILL BACK SLIGHTLY TO SOUTHWEST TONIGHT...AS THE FLAT UPPER
RIDGE OVER THE PACIFIC NORTHWEST MOVES SLOWLY EAST. A FRONT WILL
REMAIN ALONG THE NORTHWEST SIDE OF THE RIDGE...EXTENDING FROM
SOUTHERN BRITISH COLUMBIA SOUTHWEST INTO THE OFFSHORE WATERS. THE
AIR MASS WILL REMAIN FAIRLY MOIST...ESPECIALLY AT MIDDLE AND UPPER
LEVELS.

VFR CONDITIONS CONTINUE ACROSS THE FORECAST AREA EARLY THIS
MORNING...WITH SKY COVER ROUGHLY SCT-BKN040 BKN-060-075 AND HIGHER
BKN-OVC LAYERS ABOVE. AREAS OF LIGHT PRECIPITATION CONTINUE OVER THE
NORTH PART OF THE AREA. ON THE WHOLE THERE WILL BE LITTLE CHANGE
THROUGH TONIGHT.

KSEA...SOUTH OR SOUTHWEST WIND 6-12 KT. BKN-OVC CEILING COULD LOWER
TO AROUND 5000 FT TONIGHT BUT REMAIN VFR.   MCDONNAL

&&

.MARINE...A RIDGE WILL REMAIN OVER WESTERN WASHINGTON THROUGH
MONDAY... WHILE A FRONT EXTENDS FROM VANCOUVER ISLAND INTO THE
OFFSHORE WATERS. THE SOUTHERLY GRADIENT ASSOCIATED WITH THIS PATTERN
IS PRODUCING WINDS OF 15 TO 30 KT...WITH THE HIGHEST WINDS GENERALLY
IN THE NORTH PART OF THE FORECAST AREA.

A COLD FRONT WILL MOVE ACROSS THE COASTAL WATERS AND WESTERN
WASHINGTON LATE MONDAY AND MONDAY NIGHT...FOLLOWED BY STRONG ONSHORE
FLOW MONDAY NIGHT AND TUESDAY. THERE IS A GOOD CHANCE THAT GALE
WESTERLIES WILL OCCUR IN THE CENTRAL STRAIT OF JUAN DE FUCA AND EAST
ENTRANCE STRAIT LATER MONDAY NIGHT AND TUESDAY...AND A GALE WATCH IS
BEING ISSUED WITH THE EARLY MORNING FORECAST.

THERE WILL BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS THROUGH TUESDAY...WITH ROUGH BAR CONDITIONS AS WELL.

A WEAK RIDGE WILL BUILD OVER THE AREA WEDNESDAY AND THURSDAY.
MCDONNAL


&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.
     GALE WATCH FOR MONDAY NIGHT AND TUESDAY CENTRAL STRAIT
      AND EAST ENTRANCE STRAIT.

&&

$$

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









000
FXUS66 KSEW 290335
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
830 PM PDT SAT MAR 28 2015

.SYNOPSIS...A STALLED FRONTAL BOUNDARY WILL BRING LIGHT RAIN TO THE
NORTH INTERIOR AND COAST AT TIMES THROUGH MONDAY. A COLD FRONT WILL
MOVE THROUGH WESTERN WASHINGTON MONDAY NIGHT...BRINGING RAIN INTO
THE REST OF THE INTERIOR. UPPER LEVEL LOW PRESSURE OVER THE REGION
NEXT WEEK WILL MAINTAIN A COOL AND SHOWERY WEATHER PATTERN.

&&

.SHORT TERM...RADAR RETURNS LOOK REMARKABLY LIKE MODEL PRECIPITATION
WITH LIGHT RAIN AT TIMES OVER THE NORTH COAST AND EXTREME NORTH
INTERIOR...EXTENDING SOUTH INTO THE CENTRAL CASCADES. THIS IS
FORECAST TO BE THE PATTERN THROUGH MONDAY AND NO CHANGES TO THE
ZONES OR GRIDS ARE ANTICIPATED. HIGH TEMPERATURES WILL BE IN THE
UPPER 50S TO MID 60S. THE SNOW LEVEL WILL RISE TO 6000 FEET.

ON MONDAY NIGHT A COLD FRONT WILL FINALLY MOVE THROUGH THE AREA...
SPREADING RAIN TO EVERYWHERE. SHOWERS WILL FOLLOW TUESDAY. HIGH
TEMPERATURES ON TUESDAY WILL BE IN THE LOW TO MID 50S AND THE SNOW
LEVEL WILL FALL TO 4000 FEET. BURKE

.LONG TERM...PREVIOUS DISCUSSION...MODELS HAVE NOT BEEN AT ALL
CONSISTENT IN THE EXTENDED RANGE. THE OVERALL PATTERN LOOKS
PROGRESSIVE AND SPLIT WITH A SERIES OF WEAK SHORT WAVES PASSING NEAR
WRN WA. TIMING THESE SYSTEMS IS DIFFICULT AND IT DOESN`T SEEM
PRUDENT TO TRY PICK OUT SHORT BLOCKS OF DRY WEATHER. WILL KEEP THE
CLIMO BROAD BRUSH CHANCE OF SHOWERS IN THE FORECAST.  MERCER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT OVER WESTERN WASHINGTON THIS EVENING
WILL CONTINUE THROUGH SUNDAY AS A FLAT UPPER RIDGE REMAINS OVER THE
PACIFIC NORTHWEST. A WARM FRONT WILL REMAIN ALONG THE NORTHWEST SIDE
OF THE RIDGE...EXTENDING FROM SOUTHERN BRITISH COLUMBIA SOUTHWEST
INTO THE OFFSHORE WATERS. THE AIR MASS WILL REMAIN FAIRLY MOIST...
ESPECIALLY AT MIDDLE AND UPPER LEVELS.

SKY COVER ACROSS THE FORECAST AREA IS GENERALLY BKN-OVC BETWEEN
6000-8000 FT WITH HIGHER OVC LAYERS ABOVE. CONDITIONS WILL LOWER
SOMEWHAT TONIGHT BUT SHOULD REMAIN PREDOMINANTLY VFR. THERE WILL
PROBABLY BE SOME LIGHT PRECIPITATION IN THE NORTH PART OF THE
FORECAST AREA.

KSEA...SOUTH OR SOUTHWEST WIND 6-12 KT. BKN-OVC CEILING SHOULD LOWER
TO AROUND 5000 FT TONIGHT BUT REMAIN VFR THROUGH SUNDAY.   MCDONNAL

&&

.MARINE...A RIDGE WILL BE OVER WESTERN WASHINGTON THROUGH MONDAY
MORNING WHILE A FRONT EXTENDS FROM VANCOUVER ISLAND SOUTHWEST INTO
THE OFFSHORE WATERS. THE SOUTHERLY PRESSURE GRADIENT THAT RESULTS
SHOULD BE ENOUGH FOR SMALL CRAFT ADVISORY WINDS OVER THE COASTAL
WATERS AND WEST ENTRANCE STRAIT OF JUAN DE FUCA DURING THE PERIOD...
AND THEY SHOULD DEVELOP OVER THE INLAND WATERS LATER TONIGHT AND
SUNDAY MORNING.

A COLD FRONT WILL MOVE ACROSS THE COASTAL WATERS AND WESTERN
WASHINGTON LATE MONDAY AND MONDAY NIGHT...WITH SMALL CRAFT ADVISORY
WINDS MOST OR ALL WATERS. MODERATELY STRONG ONSHORE FLOW WILL FOLLOW
THE FRONT MONDAY NIGHT AND TUESDAY. SMALL CRAFT ADVISORY
WESTERLIES...AND POSSIBLY GALES...WILL DEVELOP IN THE CENTRAL AND
EASTERN STRAIT OF JUAN DE FUCA. A WEAK RIDGE WILL BUILD OVER THE
AREA WEDNESDAY.

THERE WILL ALSO BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS LATER TONIGHT THROUGH TUESDAY...WITH ROUGH BAR CONDITIONS AS
WELL.   MCDONNAL

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.

&&

$$

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






000
FXUS66 KSEW 290335
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
830 PM PDT SAT MAR 28 2015

.SYNOPSIS...A STALLED FRONTAL BOUNDARY WILL BRING LIGHT RAIN TO THE
NORTH INTERIOR AND COAST AT TIMES THROUGH MONDAY. A COLD FRONT WILL
MOVE THROUGH WESTERN WASHINGTON MONDAY NIGHT...BRINGING RAIN INTO
THE REST OF THE INTERIOR. UPPER LEVEL LOW PRESSURE OVER THE REGION
NEXT WEEK WILL MAINTAIN A COOL AND SHOWERY WEATHER PATTERN.

&&

.SHORT TERM...RADAR RETURNS LOOK REMARKABLY LIKE MODEL PRECIPITATION
WITH LIGHT RAIN AT TIMES OVER THE NORTH COAST AND EXTREME NORTH
INTERIOR...EXTENDING SOUTH INTO THE CENTRAL CASCADES. THIS IS
FORECAST TO BE THE PATTERN THROUGH MONDAY AND NO CHANGES TO THE
ZONES OR GRIDS ARE ANTICIPATED. HIGH TEMPERATURES WILL BE IN THE
UPPER 50S TO MID 60S. THE SNOW LEVEL WILL RISE TO 6000 FEET.

ON MONDAY NIGHT A COLD FRONT WILL FINALLY MOVE THROUGH THE AREA...
SPREADING RAIN TO EVERYWHERE. SHOWERS WILL FOLLOW TUESDAY. HIGH
TEMPERATURES ON TUESDAY WILL BE IN THE LOW TO MID 50S AND THE SNOW
LEVEL WILL FALL TO 4000 FEET. BURKE

.LONG TERM...PREVIOUS DISCUSSION...MODELS HAVE NOT BEEN AT ALL
CONSISTENT IN THE EXTENDED RANGE. THE OVERALL PATTERN LOOKS
PROGRESSIVE AND SPLIT WITH A SERIES OF WEAK SHORT WAVES PASSING NEAR
WRN WA. TIMING THESE SYSTEMS IS DIFFICULT AND IT DOESN`T SEEM
PRUDENT TO TRY PICK OUT SHORT BLOCKS OF DRY WEATHER. WILL KEEP THE
CLIMO BROAD BRUSH CHANCE OF SHOWERS IN THE FORECAST.  MERCER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...WESTERLY FLOW ALOFT OVER WESTERN WASHINGTON THIS EVENING
WILL CONTINUE THROUGH SUNDAY AS A FLAT UPPER RIDGE REMAINS OVER THE
PACIFIC NORTHWEST. A WARM FRONT WILL REMAIN ALONG THE NORTHWEST SIDE
OF THE RIDGE...EXTENDING FROM SOUTHERN BRITISH COLUMBIA SOUTHWEST
INTO THE OFFSHORE WATERS. THE AIR MASS WILL REMAIN FAIRLY MOIST...
ESPECIALLY AT MIDDLE AND UPPER LEVELS.

SKY COVER ACROSS THE FORECAST AREA IS GENERALLY BKN-OVC BETWEEN
6000-8000 FT WITH HIGHER OVC LAYERS ABOVE. CONDITIONS WILL LOWER
SOMEWHAT TONIGHT BUT SHOULD REMAIN PREDOMINANTLY VFR. THERE WILL
PROBABLY BE SOME LIGHT PRECIPITATION IN THE NORTH PART OF THE
FORECAST AREA.

KSEA...SOUTH OR SOUTHWEST WIND 6-12 KT. BKN-OVC CEILING SHOULD LOWER
TO AROUND 5000 FT TONIGHT BUT REMAIN VFR THROUGH SUNDAY.   MCDONNAL

&&

.MARINE...A RIDGE WILL BE OVER WESTERN WASHINGTON THROUGH MONDAY
MORNING WHILE A FRONT EXTENDS FROM VANCOUVER ISLAND SOUTHWEST INTO
THE OFFSHORE WATERS. THE SOUTHERLY PRESSURE GRADIENT THAT RESULTS
SHOULD BE ENOUGH FOR SMALL CRAFT ADVISORY WINDS OVER THE COASTAL
WATERS AND WEST ENTRANCE STRAIT OF JUAN DE FUCA DURING THE PERIOD...
AND THEY SHOULD DEVELOP OVER THE INLAND WATERS LATER TONIGHT AND
SUNDAY MORNING.

A COLD FRONT WILL MOVE ACROSS THE COASTAL WATERS AND WESTERN
WASHINGTON LATE MONDAY AND MONDAY NIGHT...WITH SMALL CRAFT ADVISORY
WINDS MOST OR ALL WATERS. MODERATELY STRONG ONSHORE FLOW WILL FOLLOW
THE FRONT MONDAY NIGHT AND TUESDAY. SMALL CRAFT ADVISORY
WESTERLIES...AND POSSIBLY GALES...WILL DEVELOP IN THE CENTRAL AND
EASTERN STRAIT OF JUAN DE FUCA. A WEAK RIDGE WILL BUILD OVER THE
AREA WEDNESDAY.

THERE WILL ALSO BE A WESTERLY SWELL OF 10 TO 12 FT OVER THE COASTAL
WATERS LATER TONIGHT THROUGH TUESDAY...WITH ROUGH BAR CONDITIONS AS
WELL.   MCDONNAL

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.

&&

$$

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







000
FXUS66 KSEW 282140
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PDT SAT MAR 28 2015

.SYNOPSIS...A STALLED FRONTAL BOUNDARY WILL BRING LIGHT RAIN TO THE
NORTH INTERIOR AND COAST AT TIMES THROUGH MONDAY. THE COLD FRONT
WILL REACH WESTERN WASHINGTON MONDAY NIGHT...BRINGING RAIN BACK INTO
THE REST OF THE INTERIOR. UPPER LEVEL LOW PRESSURE OVER THE REGION
NEXT WEEK WILL MAINTAIN A COOL AND SHOWERY WEATHER PATTERN.

&&

.SHORT TERM...SKIES ARE PARTLY CLOUDY ACROSS INTERIOR WRN WA WITH
JUST A FEW WEAK DIURNALLY DRIVEN SHOWERS ON RADAR THIS AFTERNOON.
SATELLITE IMAGERY SHOWS A THICK MASS CLOUDS MOVING IN FROM THE
PACIFIC...SO AN INCREASE IN MID/HIGH CLOUDS ARE EXPECTED TONIGHT.
THE KLGX COASTAL RADAR SHOWS A BAND OF STEADIER RAINFALL MOVING ONTO
THE N COAST. MODELS INDICATE A WARM FRONTAL FEATURE WILL LIFT ACROSS
WRN WA TONIGHT AND STALL MAINLY OVER BRITISH COLUMBIA SUNDAY INTO
MONDAY. MOST OF THIS RAINFALL WILL SKIRT THE N
COAST...OLYMPICS...STRAIT...AND FAR N INTERIOR. PUGET SOUND TO THE
SW INTERIOR WILL PROBABLY STAY MOSTLY DRY ALTHOUGH SOME SPRINKLES
ARE NOT OUT OF THE QUESTION...ESPECIALLY TONIGHT. THE GFS40 LOOKS TO
AGGRESSIVE WITH QPF WITH THE DRIER NAM-12 FAVORED WHICH KEEPS THE
PUGET SOUND REGION SWD GENERALLY DRY.

HIGH PRESSURE AMPLIFIES OVER THE ROCKIES AND A TROUGH DEEPENS
OFFSHORE. THE COLD FRONT LURKING OFFSHORE WILL FINALLY PUSH THROUGH
WRN WA MONDAY NIGHT...A LITTLE QUICKER THAN SOME PREVIOUS MODEL RUNS
SHOWED. LIKELY POPS ARE IN THE FORECAST MONDAY NIGHT AND TUESDAY FOR
THE FRONT AND TRAILING UPPER TROUGH. TEMPERATURES THE NEXT COUPLE
DAYS SHOULD MAKE THE LOW OR MID 60S AROUND PUGET SOUND BUT HIGHS
WILL COME DOWN A GOOD 10 DEGREES ON TUESDAY.

.LONG TERM...MODELS HAVE NOT BEEN AT ALL CONSISTENT IN THE EXTENDED
RANGE. THE OVERALL PATTERN LOOKS PROGRESSIVE AND SPLIT WITH A SERIES
OF WEAK SHORT WAVES PASSING NEAR WRN WA. TIMING THESE SYSTEMS IS
DIFFICULT AND IT DOESN`T SEEM PRUDENT TO TRY PICK OUT SHORT BLOCKS
OF DRY WEATHER. WILL KEEP THE CLIMO BROAD BRUSH CHANCE OF SHOWERS IN
THE FORECAST.  MERCER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...THE FLAT UPPER LEVEL RIDGE OVER W WA AT 21Z WILL SLIDE
OVER E WA BY 12Z AS A WARM FRONT MOVES OVER VANCOUVER ISLAND.
MODERATE W FLOW ALOFT WILL CONTINUE OVER THE AREA...AND WILL BECOME
INCREASINGLY MOIST FROM THE APPROACHING WARM FRONT.

THE LOWER AIR MASS OVER W WA WAS SOMEWHAT MOIST AND WEAKLY UNSTABLE
AT 21Z THIS AFTERNOON WITH AREAS OF VFR STRATOCUMULUS. MID AND HIGH
LEVEL MOISTURE JUST OFFSHORE ASSOCIATED WITH THE APPROACHING WARM
FRONT WAS BEGINNING TO REACH NW WA AND WILL COVER MAINLY THE N TWO
THIRDS OF WA WITH CIGS BKN-OVC050 AND HIGHER FROM AROUND 00Z TO
BEYOND 12Z. PRESSURE FALLS OVER SOUTHERN B.C. WILL ALLOW GUSTY S
WINDS TO DEVELOP OVER THE INTERIOR LATE TONIGHT.

KSEA...VFR CIGS WILL PREVAIL OVER THE TERMINAL THROUGH 12Z. MOISTURE
FROM A WARM FRONT HEADED TOWARD B.C. WILL SPREAD OVER THE TERMINAL
AS CIGS BKN-OVC050 AND HIGHER. SURFACE WINDS BE S 12G20KT THROUGH
ABOUT 00Z THEN WEAKEN TO S 5-10KT OVERNIGHT. KAM

&&

.MARINE...THE SMALL WEAK SURFACE RIDGE BUILDING OVER W WA THIS
AFTERNOON WILL REMAIN IN PLACE THROUGH MONDAY MORNING. THE DOMINANT
FEATURE WILL BE THE WARM FRONT THAT WILL MOVE OVER VANCOUVER ISLAND
TONIGHT. PRESSURE FALLS ALONG THE B.C. COAST AHEAD OF THE WARM FRONT
WILL ALLOW MODERATE S FLOW TO DEVELOP OVER WA WATERS TONIGHT AND
SUNDAY. SCA ARE UP FOR THE COAST AND FOR ALL INLAND WATERS EXCEPT
FOR THE CENTRAL STRAIT.

THE TRAILING COLD FRONT WILL CROSS W WA MONDAY EVENING...THEN STRONG
ONSHORE FLOW WILL DEVELOP BEHIND THE FRONT MONDAY NIGHT. PRESSURE
GRADIENT DEPICTED ON THE GFS AND ECMWF SEEM STRONG ENOUGH FOR
GALES...SIMILAR TO THE COLD FRONT LAST NIGHT...BUT THE WRF-GFS HOLDS
WINDS IN THE SCA RANGE. THE GFS AND ECMWF ALSO SEEM TO DELAY THE
STRENGTHENING ONSHORE FLOW JUST A BIT WHILE THE CANADIAN IS FASTER.
I WILL STICK WITH THE WRF-GFS TIMING FOR NOW BUT STRONG W FLOW
THROUGH THE STRAIT COULD BEGIN EARLIER MONDAY EVENING...AND
COULD REACH GALE FORCE. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.

&&

$$

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
















000
FXUS66 KSEW 282140
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PDT SAT MAR 28 2015

.SYNOPSIS...A STALLED FRONTAL BOUNDARY WILL BRING LIGHT RAIN TO THE
NORTH INTERIOR AND COAST AT TIMES THROUGH MONDAY. THE COLD FRONT
WILL REACH WESTERN WASHINGTON MONDAY NIGHT...BRINGING RAIN BACK INTO
THE REST OF THE INTERIOR. UPPER LEVEL LOW PRESSURE OVER THE REGION
NEXT WEEK WILL MAINTAIN A COOL AND SHOWERY WEATHER PATTERN.

&&

.SHORT TERM...SKIES ARE PARTLY CLOUDY ACROSS INTERIOR WRN WA WITH
JUST A FEW WEAK DIURNALLY DRIVEN SHOWERS ON RADAR THIS AFTERNOON.
SATELLITE IMAGERY SHOWS A THICK MASS CLOUDS MOVING IN FROM THE
PACIFIC...SO AN INCREASE IN MID/HIGH CLOUDS ARE EXPECTED TONIGHT.
THE KLGX COASTAL RADAR SHOWS A BAND OF STEADIER RAINFALL MOVING ONTO
THE N COAST. MODELS INDICATE A WARM FRONTAL FEATURE WILL LIFT ACROSS
WRN WA TONIGHT AND STALL MAINLY OVER BRITISH COLUMBIA SUNDAY INTO
MONDAY. MOST OF THIS RAINFALL WILL SKIRT THE N
COAST...OLYMPICS...STRAIT...AND FAR N INTERIOR. PUGET SOUND TO THE
SW INTERIOR WILL PROBABLY STAY MOSTLY DRY ALTHOUGH SOME SPRINKLES
ARE NOT OUT OF THE QUESTION...ESPECIALLY TONIGHT. THE GFS40 LOOKS TO
AGGRESSIVE WITH QPF WITH THE DRIER NAM-12 FAVORED WHICH KEEPS THE
PUGET SOUND REGION SWD GENERALLY DRY.

HIGH PRESSURE AMPLIFIES OVER THE ROCKIES AND A TROUGH DEEPENS
OFFSHORE. THE COLD FRONT LURKING OFFSHORE WILL FINALLY PUSH THROUGH
WRN WA MONDAY NIGHT...A LITTLE QUICKER THAN SOME PREVIOUS MODEL RUNS
SHOWED. LIKELY POPS ARE IN THE FORECAST MONDAY NIGHT AND TUESDAY FOR
THE FRONT AND TRAILING UPPER TROUGH. TEMPERATURES THE NEXT COUPLE
DAYS SHOULD MAKE THE LOW OR MID 60S AROUND PUGET SOUND BUT HIGHS
WILL COME DOWN A GOOD 10 DEGREES ON TUESDAY.

.LONG TERM...MODELS HAVE NOT BEEN AT ALL CONSISTENT IN THE EXTENDED
RANGE. THE OVERALL PATTERN LOOKS PROGRESSIVE AND SPLIT WITH A SERIES
OF WEAK SHORT WAVES PASSING NEAR WRN WA. TIMING THESE SYSTEMS IS
DIFFICULT AND IT DOESN`T SEEM PRUDENT TO TRY PICK OUT SHORT BLOCKS
OF DRY WEATHER. WILL KEEP THE CLIMO BROAD BRUSH CHANCE OF SHOWERS IN
THE FORECAST.  MERCER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...THE FLAT UPPER LEVEL RIDGE OVER W WA AT 21Z WILL SLIDE
OVER E WA BY 12Z AS A WARM FRONT MOVES OVER VANCOUVER ISLAND.
MODERATE W FLOW ALOFT WILL CONTINUE OVER THE AREA...AND WILL BECOME
INCREASINGLY MOIST FROM THE APPROACHING WARM FRONT.

THE LOWER AIR MASS OVER W WA WAS SOMEWHAT MOIST AND WEAKLY UNSTABLE
AT 21Z THIS AFTERNOON WITH AREAS OF VFR STRATOCUMULUS. MID AND HIGH
LEVEL MOISTURE JUST OFFSHORE ASSOCIATED WITH THE APPROACHING WARM
FRONT WAS BEGINNING TO REACH NW WA AND WILL COVER MAINLY THE N TWO
THIRDS OF WA WITH CIGS BKN-OVC050 AND HIGHER FROM AROUND 00Z TO
BEYOND 12Z. PRESSURE FALLS OVER SOUTHERN B.C. WILL ALLOW GUSTY S
WINDS TO DEVELOP OVER THE INTERIOR LATE TONIGHT.

KSEA...VFR CIGS WILL PREVAIL OVER THE TERMINAL THROUGH 12Z. MOISTURE
FROM A WARM FRONT HEADED TOWARD B.C. WILL SPREAD OVER THE TERMINAL
AS CIGS BKN-OVC050 AND HIGHER. SURFACE WINDS BE S 12G20KT THROUGH
ABOUT 00Z THEN WEAKEN TO S 5-10KT OVERNIGHT. KAM

&&

.MARINE...THE SMALL WEAK SURFACE RIDGE BUILDING OVER W WA THIS
AFTERNOON WILL REMAIN IN PLACE THROUGH MONDAY MORNING. THE DOMINANT
FEATURE WILL BE THE WARM FRONT THAT WILL MOVE OVER VANCOUVER ISLAND
TONIGHT. PRESSURE FALLS ALONG THE B.C. COAST AHEAD OF THE WARM FRONT
WILL ALLOW MODERATE S FLOW TO DEVELOP OVER WA WATERS TONIGHT AND
SUNDAY. SCA ARE UP FOR THE COAST AND FOR ALL INLAND WATERS EXCEPT
FOR THE CENTRAL STRAIT.

THE TRAILING COLD FRONT WILL CROSS W WA MONDAY EVENING...THEN STRONG
ONSHORE FLOW WILL DEVELOP BEHIND THE FRONT MONDAY NIGHT. PRESSURE
GRADIENT DEPICTED ON THE GFS AND ECMWF SEEM STRONG ENOUGH FOR
GALES...SIMILAR TO THE COLD FRONT LAST NIGHT...BUT THE WRF-GFS HOLDS
WINDS IN THE SCA RANGE. THE GFS AND ECMWF ALSO SEEM TO DELAY THE
STRENGTHENING ONSHORE FLOW JUST A BIT WHILE THE CANADIAN IS FASTER.
I WILL STICK WITH THE WRF-GFS TIMING FOR NOW BUT STRONG W FLOW
THROUGH THE STRAIT COULD BEGIN EARLIER MONDAY EVENING...AND
COULD REACH GALE FORCE. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT THE CENTRAL STRAIT.
     SMALL CRAFT ADVISORY GRAYS HARBOR FOR ROUGH BAR.

&&

$$

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















000
FXUS66 KSEW 281623
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
915 AM PDT SAT MAR 28 2015

.SYNOPSIS...SHOWERS WILL GENERALLY DECREASE TODAY BEHIND A FRONT.
WEAK HIGH PRESSURE WILL KEEP WEATHER SYSTEMS MAINLY NORTH OF THE
AREA TONIGHT THROUGH EARLY MONDAY. A COLD FRONT WILL REACH WESTERN
WASHINGTON LATE MONDAY WITH RAIN. UPPER LEVEL LOW PRESSURE WILL BE
OVER THE AREA FOR MUCH OF THE REST OF THE WEEK.

&&

.SHORT TERM...POST FRONTAL SHOWERS ARE STREAMING INTO WRN WA THIS
MORNING WITH BREEZY WINDS. GALES OCCURRED IN THE STRAIT EARLIER AND
THIS OUTFLOW WILL MEET UP WITH THE S-SW FLOW IN PUGET SOUND
PRODUCING A CONVERGENCE ZONE TODAY. WESTERLY FLOW AT 850 MPH SHOULD
KEEP MOST THE PRECIPITATION FOCUSED ALONG THE W SLOPES OF THE
CASCADES AND FOOTHILLS OF FAR NRN KING AND SNOHOMISH COUNTIES.
THE NAM-12 HOLDS ONTO THE CONVERGENCE ZONE THROUGH THE DAY WHILE THE
HRRR IS LESS ENTHUSIASTIC. HOWEVER...THE OVERALL PATTERN SUGGESTS IT
WILL HANG AROUND INTO THE AFTERNOON HOURS TODAY. JUST A CHANCE OF
SHOWERS ELSEWHERE. SNOW LEVELS FELL OVER THE PAST FEW HOURS...DOWN
TO ABOUT 4500 FEET NORTH AND 5000 FEET SOUTH. MOUNT BAKER PICKED UP
A COUPLE INCHES OF SNOW AS DID HURRICANE RIDGE.  NOT
SURPRISINGLY...IT REMAINED TOO WARM IN THE PASSES FOR ACCUMULATING
SNOW. IT WAS ALSO BREEZY BEHIND THE FRONTAL PASSAGE LAST NIGHT WITH
GUSTS OVER 30 MPH INTO THIS MORNING. GRADIENTS ARE EASING WITH
KPDX-KBLI DOWN TO +6 MB FROM ABOUT +8 MB AT THE PEAK EARLIER. WINDS
WILL CONTINUE TO GRADUALLY EASE THROUGH THE DAY.

THE TROUGH PULLS AWAY FROM THE AREA TONIGHT WITH NEXT SYSTEM
DIRECTING MOIST W-SW FLOW INTO MAINLY BRITISH COLUMBIA. 06Z/12Z
MODELS HAVE TRENDED FURTHER N WITH THE STALLED FRONTAL BOUNDARY
TONIGHT THROUGH MONDAY MORNING. NEWEST MODELS KEEP PRECIPITATION
CONFINED TO MAINLY THE N COAST/OLYMPICS AND FAR N INTERIOR. PUGET
SOUND SWD LOOKS TO STAY MOSTLY DRY AND A TOUCH WARMER WITH HIGHS IN
THE LOW 60S.

A BROAD TROUGH WILL DIG OFFSHORE DRAGGING A FRONT ACROSS THE AREA
LATE MONDAY/MONDAY NIGHT. THIS STILL APPEARS THE MOST LIKELY PERIOD
FOR MORE WIDESPREAD LIGHT RAINFALL. MERCER

.LONG TERM...FROM PREVIOUS DISCUSSION...A BROAD UPPER TROUGH WILL BE
OVER THE REGION TUESDAY THROUGH FRIDAY FOR SHOWERY WEATHER AT TIMES.
MODELS SUGGEST AN UPPER RIDGE WILL BRING DRIER WEATHER THURSDAY.
MODELS ARE IN POOR AGREEMENT WITH HOW THINGS WILL PROGRESS AFTER
THAT. SCHNEIDER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A FLAT UPPER LEVEL RIDGE OVER W WA WILL SLIDE OVER E WA
TONIGHT. MODERATE W FLOW ALOFT WILL CONTINUE OVER THE AREA. THE
PUGET SOUND CONVERGENCE THAT FORMED OVERNIGHT HAS MOVED OVER THE
CASCADES AND IS DISSIPATING.

WEAKENING W ONSHORE FLOW HAS LEFT THE LOWER AIR MASS OVER W WA
SOMEWHAT MOIST...BUT THE MODERATE W FLOW HAS ALSO CAUSED CLEARING IN
THE LEE OF THE OLYMPICS AND VANCOUVER ISLAND. THE W FLOW IS ALSO
PRODUCING CLOUDS AND SCATTERED SHOWERS OVER THE W SLOPES OF THE
CASCADES AND OLYMPICS. THE LOWER AIR MASS IS ALSO WEAKLY UNSTABLE
AND AREAS OF CUMULUS OR STRATOCUMULUS WITH BASES 020-040 WILL BE
PRESENT. LOW LEVEL WINDS WILL REMAIN GUSTY THROUGH 22Z.

A WARM FRONT APPROACHING VANCOUVER ISLAND WILL SPREAD MID LEVEL
MOISTURE OVER MAINLY THE N TWO THIRDS OF W WA BEGINNING AFTER 22Z.

KSEA...MVFR CIGS BKN018-030 ARE EXPECTED THROUGH 21Z...LIFTING TO
SCT-BKN040 OR BETTER AFTER 21Z. THE CONVERGENCE ZONE IS NO LONGER A
FACTOR. SURFACE WINDS WILL REMAIN S 14G24KT THROUGH ABOUT 00Z WITH A
GRADUAL WEAKENING TREND AS 00Z APPROACHES. KAM

&&

.MARINE...STRONG ONSHORE FLOW EARLIER THIS MORNING IS WEAKENING AS A
SURFACE RIDGE BUILDS OVER W WA...BUT PER RACE ROCKS THE FLOW IS NOT
WEAKENING QUITE AS QUICKLY AS EXPECTED IN THE STRAIT. THE GALE WILL
BE EXTENDED FOR A COUPLE MORE HOURS UNTIL 11 AM FOLLOWED BY A
TRANSITION SCA EARLY THROUGH EARLY THIS AFTERNOON. WINDS OVER THE
REMAINDER OF THE INLAND WATERS HAVE EASED BELOW SCA LEVELS THIS
MORNING BUT GUSTY WINDS TODAY MAY COME CLOSE TO SCA LEVELS.

MODELS SEEM TO BE CONSISTENT IN THEIR HANDLING OF THE WARM ADVECTION
APPROACHING VANCOUVER ISLAND TODAY. PRESSURE FALLS CAUSED BY THE
WARM FRONT REACHING VANCOUVER ISLAND LATE TODAY WILL INCREASE THE S
WINDS OVER THE COASTAL WATERS LATE THIS AFTERNOON AND TONIGHT...AND
OVER THE INLAND WATERS ON SUNDAY. AN SCA IS ALREADY IN EFFECT FOR
THE COAST. SCA WINDS ARE ALREADY IN THE FORECAST FOR THE INTERIOR.

S FLOW SHOULD EASE LATE SUNDAY AS THE WARM FRONT MOVES N. THE
TRAILING COLD FRONT WILL CROSS W WA LATE MONDAY. STRONG ONSHORE FLOW
BEHIND THE COLD FRONT WILL PROBABLY PRODUCE GALES IN THE STRAIT
AGAIN MONDAY NIGHT AND TUESDAY. KAM

&&

$$

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













000
FXUS66 KSEW 281623
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
915 AM PDT SAT MAR 28 2015

.SYNOPSIS...SHOWERS WILL GENERALLY DECREASE TODAY BEHIND A FRONT.
WEAK HIGH PRESSURE WILL KEEP WEATHER SYSTEMS MAINLY NORTH OF THE
AREA TONIGHT THROUGH EARLY MONDAY. A COLD FRONT WILL REACH WESTERN
WASHINGTON LATE MONDAY WITH RAIN. UPPER LEVEL LOW PRESSURE WILL BE
OVER THE AREA FOR MUCH OF THE REST OF THE WEEK.

&&

.SHORT TERM...POST FRONTAL SHOWERS ARE STREAMING INTO WRN WA THIS
MORNING WITH BREEZY WINDS. GALES OCCURRED IN THE STRAIT EARLIER AND
THIS OUTFLOW WILL MEET UP WITH THE S-SW FLOW IN PUGET SOUND
PRODUCING A CONVERGENCE ZONE TODAY. WESTERLY FLOW AT 850 MPH SHOULD
KEEP MOST THE PRECIPITATION FOCUSED ALONG THE W SLOPES OF THE
CASCADES AND FOOTHILLS OF FAR NRN KING AND SNOHOMISH COUNTIES.
THE NAM-12 HOLDS ONTO THE CONVERGENCE ZONE THROUGH THE DAY WHILE THE
HRRR IS LESS ENTHUSIASTIC. HOWEVER...THE OVERALL PATTERN SUGGESTS IT
WILL HANG AROUND INTO THE AFTERNOON HOURS TODAY. JUST A CHANCE OF
SHOWERS ELSEWHERE. SNOW LEVELS FELL OVER THE PAST FEW HOURS...DOWN
TO ABOUT 4500 FEET NORTH AND 5000 FEET SOUTH. MOUNT BAKER PICKED UP
A COUPLE INCHES OF SNOW AS DID HURRICANE RIDGE.  NOT
SURPRISINGLY...IT REMAINED TOO WARM IN THE PASSES FOR ACCUMULATING
SNOW. IT WAS ALSO BREEZY BEHIND THE FRONTAL PASSAGE LAST NIGHT WITH
GUSTS OVER 30 MPH INTO THIS MORNING. GRADIENTS ARE EASING WITH
KPDX-KBLI DOWN TO +6 MB FROM ABOUT +8 MB AT THE PEAK EARLIER. WINDS
WILL CONTINUE TO GRADUALLY EASE THROUGH THE DAY.

THE TROUGH PULLS AWAY FROM THE AREA TONIGHT WITH NEXT SYSTEM
DIRECTING MOIST W-SW FLOW INTO MAINLY BRITISH COLUMBIA. 06Z/12Z
MODELS HAVE TRENDED FURTHER N WITH THE STALLED FRONTAL BOUNDARY
TONIGHT THROUGH MONDAY MORNING. NEWEST MODELS KEEP PRECIPITATION
CONFINED TO MAINLY THE N COAST/OLYMPICS AND FAR N INTERIOR. PUGET
SOUND SWD LOOKS TO STAY MOSTLY DRY AND A TOUCH WARMER WITH HIGHS IN
THE LOW 60S.

A BROAD TROUGH WILL DIG OFFSHORE DRAGGING A FRONT ACROSS THE AREA
LATE MONDAY/MONDAY NIGHT. THIS STILL APPEARS THE MOST LIKELY PERIOD
FOR MORE WIDESPREAD LIGHT RAINFALL. MERCER

.LONG TERM...FROM PREVIOUS DISCUSSION...A BROAD UPPER TROUGH WILL BE
OVER THE REGION TUESDAY THROUGH FRIDAY FOR SHOWERY WEATHER AT TIMES.
MODELS SUGGEST AN UPPER RIDGE WILL BRING DRIER WEATHER THURSDAY.
MODELS ARE IN POOR AGREEMENT WITH HOW THINGS WILL PROGRESS AFTER
THAT. SCHNEIDER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A FLAT UPPER LEVEL RIDGE OVER W WA WILL SLIDE OVER E WA
TONIGHT. MODERATE W FLOW ALOFT WILL CONTINUE OVER THE AREA. THE
PUGET SOUND CONVERGENCE THAT FORMED OVERNIGHT HAS MOVED OVER THE
CASCADES AND IS DISSIPATING.

WEAKENING W ONSHORE FLOW HAS LEFT THE LOWER AIR MASS OVER W WA
SOMEWHAT MOIST...BUT THE MODERATE W FLOW HAS ALSO CAUSED CLEARING IN
THE LEE OF THE OLYMPICS AND VANCOUVER ISLAND. THE W FLOW IS ALSO
PRODUCING CLOUDS AND SCATTERED SHOWERS OVER THE W SLOPES OF THE
CASCADES AND OLYMPICS. THE LOWER AIR MASS IS ALSO WEAKLY UNSTABLE
AND AREAS OF CUMULUS OR STRATOCUMULUS WITH BASES 020-040 WILL BE
PRESENT. LOW LEVEL WINDS WILL REMAIN GUSTY THROUGH 22Z.

A WARM FRONT APPROACHING VANCOUVER ISLAND WILL SPREAD MID LEVEL
MOISTURE OVER MAINLY THE N TWO THIRDS OF W WA BEGINNING AFTER 22Z.

KSEA...MVFR CIGS BKN018-030 ARE EXPECTED THROUGH 21Z...LIFTING TO
SCT-BKN040 OR BETTER AFTER 21Z. THE CONVERGENCE ZONE IS NO LONGER A
FACTOR. SURFACE WINDS WILL REMAIN S 14G24KT THROUGH ABOUT 00Z WITH A
GRADUAL WEAKENING TREND AS 00Z APPROACHES. KAM

&&

.MARINE...STRONG ONSHORE FLOW EARLIER THIS MORNING IS WEAKENING AS A
SURFACE RIDGE BUILDS OVER W WA...BUT PER RACE ROCKS THE FLOW IS NOT
WEAKENING QUITE AS QUICKLY AS EXPECTED IN THE STRAIT. THE GALE WILL
BE EXTENDED FOR A COUPLE MORE HOURS UNTIL 11 AM FOLLOWED BY A
TRANSITION SCA EARLY THROUGH EARLY THIS AFTERNOON. WINDS OVER THE
REMAINDER OF THE INLAND WATERS HAVE EASED BELOW SCA LEVELS THIS
MORNING BUT GUSTY WINDS TODAY MAY COME CLOSE TO SCA LEVELS.

MODELS SEEM TO BE CONSISTENT IN THEIR HANDLING OF THE WARM ADVECTION
APPROACHING VANCOUVER ISLAND TODAY. PRESSURE FALLS CAUSED BY THE
WARM FRONT REACHING VANCOUVER ISLAND LATE TODAY WILL INCREASE THE S
WINDS OVER THE COASTAL WATERS LATE THIS AFTERNOON AND TONIGHT...AND
OVER THE INLAND WATERS ON SUNDAY. AN SCA IS ALREADY IN EFFECT FOR
THE COAST. SCA WINDS ARE ALREADY IN THE FORECAST FOR THE INTERIOR.

S FLOW SHOULD EASE LATE SUNDAY AS THE WARM FRONT MOVES N. THE
TRAILING COLD FRONT WILL CROSS W WA LATE MONDAY. STRONG ONSHORE FLOW
BEHIND THE COLD FRONT WILL PROBABLY PRODUCE GALES IN THE STRAIT
AGAIN MONDAY NIGHT AND TUESDAY. KAM

&&

$$

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












000
FXUS66 KSEW 281623
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
915 AM PDT SAT MAR 28 2015

.SYNOPSIS...SHOWERS WILL GENERALLY DECREASE TODAY BEHIND A FRONT.
WEAK HIGH PRESSURE WILL KEEP WEATHER SYSTEMS MAINLY NORTH OF THE
AREA TONIGHT THROUGH EARLY MONDAY. A COLD FRONT WILL REACH WESTERN
WASHINGTON LATE MONDAY WITH RAIN. UPPER LEVEL LOW PRESSURE WILL BE
OVER THE AREA FOR MUCH OF THE REST OF THE WEEK.

&&

.SHORT TERM...POST FRONTAL SHOWERS ARE STREAMING INTO WRN WA THIS
MORNING WITH BREEZY WINDS. GALES OCCURRED IN THE STRAIT EARLIER AND
THIS OUTFLOW WILL MEET UP WITH THE S-SW FLOW IN PUGET SOUND
PRODUCING A CONVERGENCE ZONE TODAY. WESTERLY FLOW AT 850 MPH SHOULD
KEEP MOST THE PRECIPITATION FOCUSED ALONG THE W SLOPES OF THE
CASCADES AND FOOTHILLS OF FAR NRN KING AND SNOHOMISH COUNTIES.
THE NAM-12 HOLDS ONTO THE CONVERGENCE ZONE THROUGH THE DAY WHILE THE
HRRR IS LESS ENTHUSIASTIC. HOWEVER...THE OVERALL PATTERN SUGGESTS IT
WILL HANG AROUND INTO THE AFTERNOON HOURS TODAY. JUST A CHANCE OF
SHOWERS ELSEWHERE. SNOW LEVELS FELL OVER THE PAST FEW HOURS...DOWN
TO ABOUT 4500 FEET NORTH AND 5000 FEET SOUTH. MOUNT BAKER PICKED UP
A COUPLE INCHES OF SNOW AS DID HURRICANE RIDGE.  NOT
SURPRISINGLY...IT REMAINED TOO WARM IN THE PASSES FOR ACCUMULATING
SNOW. IT WAS ALSO BREEZY BEHIND THE FRONTAL PASSAGE LAST NIGHT WITH
GUSTS OVER 30 MPH INTO THIS MORNING. GRADIENTS ARE EASING WITH
KPDX-KBLI DOWN TO +6 MB FROM ABOUT +8 MB AT THE PEAK EARLIER. WINDS
WILL CONTINUE TO GRADUALLY EASE THROUGH THE DAY.

THE TROUGH PULLS AWAY FROM THE AREA TONIGHT WITH NEXT SYSTEM
DIRECTING MOIST W-SW FLOW INTO MAINLY BRITISH COLUMBIA. 06Z/12Z
MODELS HAVE TRENDED FURTHER N WITH THE STALLED FRONTAL BOUNDARY
TONIGHT THROUGH MONDAY MORNING. NEWEST MODELS KEEP PRECIPITATION
CONFINED TO MAINLY THE N COAST/OLYMPICS AND FAR N INTERIOR. PUGET
SOUND SWD LOOKS TO STAY MOSTLY DRY AND A TOUCH WARMER WITH HIGHS IN
THE LOW 60S.

A BROAD TROUGH WILL DIG OFFSHORE DRAGGING A FRONT ACROSS THE AREA
LATE MONDAY/MONDAY NIGHT. THIS STILL APPEARS THE MOST LIKELY PERIOD
FOR MORE WIDESPREAD LIGHT RAINFALL. MERCER

.LONG TERM...FROM PREVIOUS DISCUSSION...A BROAD UPPER TROUGH WILL BE
OVER THE REGION TUESDAY THROUGH FRIDAY FOR SHOWERY WEATHER AT TIMES.
MODELS SUGGEST AN UPPER RIDGE WILL BRING DRIER WEATHER THURSDAY.
MODELS ARE IN POOR AGREEMENT WITH HOW THINGS WILL PROGRESS AFTER
THAT. SCHNEIDER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A FLAT UPPER LEVEL RIDGE OVER W WA WILL SLIDE OVER E WA
TONIGHT. MODERATE W FLOW ALOFT WILL CONTINUE OVER THE AREA. THE
PUGET SOUND CONVERGENCE THAT FORMED OVERNIGHT HAS MOVED OVER THE
CASCADES AND IS DISSIPATING.

WEAKENING W ONSHORE FLOW HAS LEFT THE LOWER AIR MASS OVER W WA
SOMEWHAT MOIST...BUT THE MODERATE W FLOW HAS ALSO CAUSED CLEARING IN
THE LEE OF THE OLYMPICS AND VANCOUVER ISLAND. THE W FLOW IS ALSO
PRODUCING CLOUDS AND SCATTERED SHOWERS OVER THE W SLOPES OF THE
CASCADES AND OLYMPICS. THE LOWER AIR MASS IS ALSO WEAKLY UNSTABLE
AND AREAS OF CUMULUS OR STRATOCUMULUS WITH BASES 020-040 WILL BE
PRESENT. LOW LEVEL WINDS WILL REMAIN GUSTY THROUGH 22Z.

A WARM FRONT APPROACHING VANCOUVER ISLAND WILL SPREAD MID LEVEL
MOISTURE OVER MAINLY THE N TWO THIRDS OF W WA BEGINNING AFTER 22Z.

KSEA...MVFR CIGS BKN018-030 ARE EXPECTED THROUGH 21Z...LIFTING TO
SCT-BKN040 OR BETTER AFTER 21Z. THE CONVERGENCE ZONE IS NO LONGER A
FACTOR. SURFACE WINDS WILL REMAIN S 14G24KT THROUGH ABOUT 00Z WITH A
GRADUAL WEAKENING TREND AS 00Z APPROACHES. KAM

&&

.MARINE...STRONG ONSHORE FLOW EARLIER THIS MORNING IS WEAKENING AS A
SURFACE RIDGE BUILDS OVER W WA...BUT PER RACE ROCKS THE FLOW IS NOT
WEAKENING QUITE AS QUICKLY AS EXPECTED IN THE STRAIT. THE GALE WILL
BE EXTENDED FOR A COUPLE MORE HOURS UNTIL 11 AM FOLLOWED BY A
TRANSITION SCA EARLY THROUGH EARLY THIS AFTERNOON. WINDS OVER THE
REMAINDER OF THE INLAND WATERS HAVE EASED BELOW SCA LEVELS THIS
MORNING BUT GUSTY WINDS TODAY MAY COME CLOSE TO SCA LEVELS.

MODELS SEEM TO BE CONSISTENT IN THEIR HANDLING OF THE WARM ADVECTION
APPROACHING VANCOUVER ISLAND TODAY. PRESSURE FALLS CAUSED BY THE
WARM FRONT REACHING VANCOUVER ISLAND LATE TODAY WILL INCREASE THE S
WINDS OVER THE COASTAL WATERS LATE THIS AFTERNOON AND TONIGHT...AND
OVER THE INLAND WATERS ON SUNDAY. AN SCA IS ALREADY IN EFFECT FOR
THE COAST. SCA WINDS ARE ALREADY IN THE FORECAST FOR THE INTERIOR.

S FLOW SHOULD EASE LATE SUNDAY AS THE WARM FRONT MOVES N. THE
TRAILING COLD FRONT WILL CROSS W WA LATE MONDAY. STRONG ONSHORE FLOW
BEHIND THE COLD FRONT WILL PROBABLY PRODUCE GALES IN THE STRAIT
AGAIN MONDAY NIGHT AND TUESDAY. KAM

&&

$$

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













000
FXUS66 KSEW 281623
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
915 AM PDT SAT MAR 28 2015

.SYNOPSIS...SHOWERS WILL GENERALLY DECREASE TODAY BEHIND A FRONT.
WEAK HIGH PRESSURE WILL KEEP WEATHER SYSTEMS MAINLY NORTH OF THE
AREA TONIGHT THROUGH EARLY MONDAY. A COLD FRONT WILL REACH WESTERN
WASHINGTON LATE MONDAY WITH RAIN. UPPER LEVEL LOW PRESSURE WILL BE
OVER THE AREA FOR MUCH OF THE REST OF THE WEEK.

&&

.SHORT TERM...POST FRONTAL SHOWERS ARE STREAMING INTO WRN WA THIS
MORNING WITH BREEZY WINDS. GALES OCCURRED IN THE STRAIT EARLIER AND
THIS OUTFLOW WILL MEET UP WITH THE S-SW FLOW IN PUGET SOUND
PRODUCING A CONVERGENCE ZONE TODAY. WESTERLY FLOW AT 850 MPH SHOULD
KEEP MOST THE PRECIPITATION FOCUSED ALONG THE W SLOPES OF THE
CASCADES AND FOOTHILLS OF FAR NRN KING AND SNOHOMISH COUNTIES.
THE NAM-12 HOLDS ONTO THE CONVERGENCE ZONE THROUGH THE DAY WHILE THE
HRRR IS LESS ENTHUSIASTIC. HOWEVER...THE OVERALL PATTERN SUGGESTS IT
WILL HANG AROUND INTO THE AFTERNOON HOURS TODAY. JUST A CHANCE OF
SHOWERS ELSEWHERE. SNOW LEVELS FELL OVER THE PAST FEW HOURS...DOWN
TO ABOUT 4500 FEET NORTH AND 5000 FEET SOUTH. MOUNT BAKER PICKED UP
A COUPLE INCHES OF SNOW AS DID HURRICANE RIDGE.  NOT
SURPRISINGLY...IT REMAINED TOO WARM IN THE PASSES FOR ACCUMULATING
SNOW. IT WAS ALSO BREEZY BEHIND THE FRONTAL PASSAGE LAST NIGHT WITH
GUSTS OVER 30 MPH INTO THIS MORNING. GRADIENTS ARE EASING WITH
KPDX-KBLI DOWN TO +6 MB FROM ABOUT +8 MB AT THE PEAK EARLIER. WINDS
WILL CONTINUE TO GRADUALLY EASE THROUGH THE DAY.

THE TROUGH PULLS AWAY FROM THE AREA TONIGHT WITH NEXT SYSTEM
DIRECTING MOIST W-SW FLOW INTO MAINLY BRITISH COLUMBIA. 06Z/12Z
MODELS HAVE TRENDED FURTHER N WITH THE STALLED FRONTAL BOUNDARY
TONIGHT THROUGH MONDAY MORNING. NEWEST MODELS KEEP PRECIPITATION
CONFINED TO MAINLY THE N COAST/OLYMPICS AND FAR N INTERIOR. PUGET
SOUND SWD LOOKS TO STAY MOSTLY DRY AND A TOUCH WARMER WITH HIGHS IN
THE LOW 60S.

A BROAD TROUGH WILL DIG OFFSHORE DRAGGING A FRONT ACROSS THE AREA
LATE MONDAY/MONDAY NIGHT. THIS STILL APPEARS THE MOST LIKELY PERIOD
FOR MORE WIDESPREAD LIGHT RAINFALL. MERCER

.LONG TERM...FROM PREVIOUS DISCUSSION...A BROAD UPPER TROUGH WILL BE
OVER THE REGION TUESDAY THROUGH FRIDAY FOR SHOWERY WEATHER AT TIMES.
MODELS SUGGEST AN UPPER RIDGE WILL BRING DRIER WEATHER THURSDAY.
MODELS ARE IN POOR AGREEMENT WITH HOW THINGS WILL PROGRESS AFTER
THAT. SCHNEIDER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A FLAT UPPER LEVEL RIDGE OVER W WA WILL SLIDE OVER E WA
TONIGHT. MODERATE W FLOW ALOFT WILL CONTINUE OVER THE AREA. THE
PUGET SOUND CONVERGENCE THAT FORMED OVERNIGHT HAS MOVED OVER THE
CASCADES AND IS DISSIPATING.

WEAKENING W ONSHORE FLOW HAS LEFT THE LOWER AIR MASS OVER W WA
SOMEWHAT MOIST...BUT THE MODERATE W FLOW HAS ALSO CAUSED CLEARING IN
THE LEE OF THE OLYMPICS AND VANCOUVER ISLAND. THE W FLOW IS ALSO
PRODUCING CLOUDS AND SCATTERED SHOWERS OVER THE W SLOPES OF THE
CASCADES AND OLYMPICS. THE LOWER AIR MASS IS ALSO WEAKLY UNSTABLE
AND AREAS OF CUMULUS OR STRATOCUMULUS WITH BASES 020-040 WILL BE
PRESENT. LOW LEVEL WINDS WILL REMAIN GUSTY THROUGH 22Z.

A WARM FRONT APPROACHING VANCOUVER ISLAND WILL SPREAD MID LEVEL
MOISTURE OVER MAINLY THE N TWO THIRDS OF W WA BEGINNING AFTER 22Z.

KSEA...MVFR CIGS BKN018-030 ARE EXPECTED THROUGH 21Z...LIFTING TO
SCT-BKN040 OR BETTER AFTER 21Z. THE CONVERGENCE ZONE IS NO LONGER A
FACTOR. SURFACE WINDS WILL REMAIN S 14G24KT THROUGH ABOUT 00Z WITH A
GRADUAL WEAKENING TREND AS 00Z APPROACHES. KAM

&&

.MARINE...STRONG ONSHORE FLOW EARLIER THIS MORNING IS WEAKENING AS A
SURFACE RIDGE BUILDS OVER W WA...BUT PER RACE ROCKS THE FLOW IS NOT
WEAKENING QUITE AS QUICKLY AS EXPECTED IN THE STRAIT. THE GALE WILL
BE EXTENDED FOR A COUPLE MORE HOURS UNTIL 11 AM FOLLOWED BY A
TRANSITION SCA EARLY THROUGH EARLY THIS AFTERNOON. WINDS OVER THE
REMAINDER OF THE INLAND WATERS HAVE EASED BELOW SCA LEVELS THIS
MORNING BUT GUSTY WINDS TODAY MAY COME CLOSE TO SCA LEVELS.

MODELS SEEM TO BE CONSISTENT IN THEIR HANDLING OF THE WARM ADVECTION
APPROACHING VANCOUVER ISLAND TODAY. PRESSURE FALLS CAUSED BY THE
WARM FRONT REACHING VANCOUVER ISLAND LATE TODAY WILL INCREASE THE S
WINDS OVER THE COASTAL WATERS LATE THIS AFTERNOON AND TONIGHT...AND
OVER THE INLAND WATERS ON SUNDAY. AN SCA IS ALREADY IN EFFECT FOR
THE COAST. SCA WINDS ARE ALREADY IN THE FORECAST FOR THE INTERIOR.

S FLOW SHOULD EASE LATE SUNDAY AS THE WARM FRONT MOVES N. THE
TRAILING COLD FRONT WILL CROSS W WA LATE MONDAY. STRONG ONSHORE FLOW
BEHIND THE COLD FRONT WILL PROBABLY PRODUCE GALES IN THE STRAIT
AGAIN MONDAY NIGHT AND TUESDAY. KAM

&&

$$

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












000
FXUS66 KSEW 280956
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 AM PDT SAT MAR 28 2015

.SYNOPSIS...SHOWERS WILL MOSTLY END EARLY THIS MORNING AS A FRONT
MOVES INLAND. A WEAK UPPER RIDGE WILL KEEP WEATHER SYSTEMS MAINLY
NORTH OF THE AREA THIS WEEKEND. A COLD FRONT WILL REACH WESTERN
WASHINGTON LATE MONDAY WITH RAIN. A COOL SHOWERY UPPER TROUGH WILL
BE OVER THE AREA FOR MUCH OF THE REST OF THE WEEK.

&&

.SHORT TERM...A FRONT WILL MOVE INLAND THIS MORNING WITH SHOWERS
MOSTLY CONCENTRATED OVER THE CASCADES AND PERHAPS A PUGET SOUND
CONVERGENCE ZONE NORTH OF SEATTLE TODAY.

A BROAD UPPER RIDGE WILL BE OVER THE WESTERN U.S. SUNDAY AND MONDAY.
THIS WILL KEEP THE RAIN THREAT MOSTLY JUST TO THE NORTH OF WESTERN
WASHINGTON. THE COAST AND NORTH CASCADES WILL HAVE THE BEST CHANCE
TO GET A LITTLE RAIN AT TIMES DURING THIS PERIOD. MOST OTHER AREAS
SHOULD BE GENERALLY DRY.

A FRONT WILL REACH THE COAST MONDAY AFTERNOON AND PUSH INTO THE
INTERIOR MONDAY EVENING FOR A ROUND OF RAIN ALL AREAS. SCHNEIDER

.LONG TERM...A BROAD UPPER TROUGH WILL BE OVER THE REGION TUESDAY
THROUGH FRIDAY FOR SHOWERY WEATHER AT TIMES. MODELS SUGGEST AN UPPER
RIDGE WILL BRING DRIER WEATHER THURSDAY. MODELS ARE IN POOR
AGREEMENT WITH HOW THINGS WILL PROGRESS AFTER THAT. SCHNEIDER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...THE SMALL UPPER TROUGH OVER WESTERN WASHINGTON EARLY
THIS MORNING WILL MOVE QUICKLY EAST...AND A FLAT UPPER RIDGE WILL
BUILD OVER THE REGION LATER TODAY AND TONIGHT. A WARM FRONT MOVING
OVER THE NORTH SIDE OF THE RIDGE WILL BRUSH THE FORECAST AREA. THE
AIR MASS WILL BE WEAKLY UNSTABLE TODAY WITH MAINLY LOWER LEVEL
MOISTURE...THEN BECOME STABLE TONIGHT WITH INCREASING MOISTURE AT
MID AND HIGH LEVELS.

THERE HAS BEEN COME CLEARING BEHIND THE COLD FRONT THAT MOVED
THROUGH WESTERN WASHINGTON DURING THE NIGHT...BUT MOIST ONSHORE FLOW
SHOULD KEEP CEILINGS GENERALLY IN THE 025-035 RANGE. SHOWERS AND
LOWER CEILINGS TO OVC020 WILL BE MAINLY CONFINED TO THE PUGET SOUND
CONVERGENCE ZONE WILL IT CONTINUES THIS MORNING...AND IT SHOULD
REMAIN NORTH OF SEATTLE. THERE WILL BE IMPROVEMENT THIS AFTERNOON...
AND CONDITIONS SHOULD REMAIN GENERALLY VFR TONIGHT.

KSEA...SOUTHWEST WIND 8-16 KT GUSTING 26 KT...EASING TO 6-12 KT THIS
AFTERNOON...THEN BECOMING SOUTH TONIGHT. THE PUGET SOUND CONVERGENCE
ZONE SHOULD REMAIN NORTH OF SEATTLE.   MCDONNAL

&&

.MARINE...STRONG ONSHORE FLOW THIS MORNING WILL EASE TODAY AS HIGH
PRESSURE BUILDS OVER THE REGION. GALE FORCE WESTERLIES IN THE
CENTRAL STRAIT OF JUAN DE FUCA AND EAST ENTRANCE STRAIT WILL
CONTINUE FOR SEVERAL MORE HOURS THIS MORNING...THEN EASE LATE THIS
MORNING AND AFTERNOON.

A WARM FRONT WILL BRUSH THE AREA AS IT MOVES INTO SOUTHERN BRITISH
COLUMBIA LATE TODAY THROUGH SUNDAY NIGHT. IT WILL PRODUCE SMALL
CRAFT ADVISORY SOUTHERLIES OVER THE COASTAL WATERS AND AT THE WEST
ENTRANCE STRAIT...WITH SMALL CRAFT ADVISORY WINDS LIKELY AT TIMES
FOR THE INLAND WATERS SUNDAY AND SUNDAY NIGHT.

A COLD FRONT WILL MOVE THROUGH THE FORECAST AREA FROM THE WEST
MONDAY WITH WIDESPREAD SMALL CRAFT ADVISORY WINDS. ONSHORE FLOW WILL
FOLLOW THE COLD FRONT MONDAY NIGHT AND TUESDAY.   MCDONNAL

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...GALE WARNING CENTRAL STRAIT AND EAST ENTRANCE STRAIT.
     SMALL CRAFT ADVISORY ALL OTHER WATERS.

&&

$$

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









000
FXUS66 KSEW 280956
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 AM PDT SAT MAR 28 2015

.SYNOPSIS...SHOWERS WILL MOSTLY END EARLY THIS MORNING AS A FRONT
MOVES INLAND. A WEAK UPPER RIDGE WILL KEEP WEATHER SYSTEMS MAINLY
NORTH OF THE AREA THIS WEEKEND. A COLD FRONT WILL REACH WESTERN
WASHINGTON LATE MONDAY WITH RAIN. A COOL SHOWERY UPPER TROUGH WILL
BE OVER THE AREA FOR MUCH OF THE REST OF THE WEEK.

&&

.SHORT TERM...A FRONT WILL MOVE INLAND THIS MORNING WITH SHOWERS
MOSTLY CONCENTRATED OVER THE CASCADES AND PERHAPS A PUGET SOUND
CONVERGENCE ZONE NORTH OF SEATTLE TODAY.

A BROAD UPPER RIDGE WILL BE OVER THE WESTERN U.S. SUNDAY AND MONDAY.
THIS WILL KEEP THE RAIN THREAT MOSTLY JUST TO THE NORTH OF WESTERN
WASHINGTON. THE COAST AND NORTH CASCADES WILL HAVE THE BEST CHANCE
TO GET A LITTLE RAIN AT TIMES DURING THIS PERIOD. MOST OTHER AREAS
SHOULD BE GENERALLY DRY.

A FRONT WILL REACH THE COAST MONDAY AFTERNOON AND PUSH INTO THE
INTERIOR MONDAY EVENING FOR A ROUND OF RAIN ALL AREAS. SCHNEIDER

.LONG TERM...A BROAD UPPER TROUGH WILL BE OVER THE REGION TUESDAY
THROUGH FRIDAY FOR SHOWERY WEATHER AT TIMES. MODELS SUGGEST AN UPPER
RIDGE WILL BRING DRIER WEATHER THURSDAY. MODELS ARE IN POOR
AGREEMENT WITH HOW THINGS WILL PROGRESS AFTER THAT. SCHNEIDER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...THE SMALL UPPER TROUGH OVER WESTERN WASHINGTON EARLY
THIS MORNING WILL MOVE QUICKLY EAST...AND A FLAT UPPER RIDGE WILL
BUILD OVER THE REGION LATER TODAY AND TONIGHT. A WARM FRONT MOVING
OVER THE NORTH SIDE OF THE RIDGE WILL BRUSH THE FORECAST AREA. THE
AIR MASS WILL BE WEAKLY UNSTABLE TODAY WITH MAINLY LOWER LEVEL
MOISTURE...THEN BECOME STABLE TONIGHT WITH INCREASING MOISTURE AT
MID AND HIGH LEVELS.

THERE HAS BEEN COME CLEARING BEHIND THE COLD FRONT THAT MOVED
THROUGH WESTERN WASHINGTON DURING THE NIGHT...BUT MOIST ONSHORE FLOW
SHOULD KEEP CEILINGS GENERALLY IN THE 025-035 RANGE. SHOWERS AND
LOWER CEILINGS TO OVC020 WILL BE MAINLY CONFINED TO THE PUGET SOUND
CONVERGENCE ZONE WILL IT CONTINUES THIS MORNING...AND IT SHOULD
REMAIN NORTH OF SEATTLE. THERE WILL BE IMPROVEMENT THIS AFTERNOON...
AND CONDITIONS SHOULD REMAIN GENERALLY VFR TONIGHT.

KSEA...SOUTHWEST WIND 8-16 KT GUSTING 26 KT...EASING TO 6-12 KT THIS
AFTERNOON...THEN BECOMING SOUTH TONIGHT. THE PUGET SOUND CONVERGENCE
ZONE SHOULD REMAIN NORTH OF SEATTLE.   MCDONNAL

&&

.MARINE...STRONG ONSHORE FLOW THIS MORNING WILL EASE TODAY AS HIGH
PRESSURE BUILDS OVER THE REGION. GALE FORCE WESTERLIES IN THE
CENTRAL STRAIT OF JUAN DE FUCA AND EAST ENTRANCE STRAIT WILL
CONTINUE FOR SEVERAL MORE HOURS THIS MORNING...THEN EASE LATE THIS
MORNING AND AFTERNOON.

A WARM FRONT WILL BRUSH THE AREA AS IT MOVES INTO SOUTHERN BRITISH
COLUMBIA LATE TODAY THROUGH SUNDAY NIGHT. IT WILL PRODUCE SMALL
CRAFT ADVISORY SOUTHERLIES OVER THE COASTAL WATERS AND AT THE WEST
ENTRANCE STRAIT...WITH SMALL CRAFT ADVISORY WINDS LIKELY AT TIMES
FOR THE INLAND WATERS SUNDAY AND SUNDAY NIGHT.

A COLD FRONT WILL MOVE THROUGH THE FORECAST AREA FROM THE WEST
MONDAY WITH WIDESPREAD SMALL CRAFT ADVISORY WINDS. ONSHORE FLOW WILL
FOLLOW THE COLD FRONT MONDAY NIGHT AND TUESDAY.   MCDONNAL

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...GALE WARNING CENTRAL STRAIT AND EAST ENTRANCE STRAIT.
     SMALL CRAFT ADVISORY ALL OTHER WATERS.

&&

$$

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










000
FXUS66 KSEW 280325
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
830 PM PDT FRI MAR 27 2015

.SYNOPSIS...RAIN WILL DEVELOP THIS EVENING...THEN CHANGE TO SHOWERS
AFTER MIDNIGHT BEHIND A FRONT. A WEAK UPPER RIDGE WILL KEEP WEATHER
SYSTEMS MAINLY NORTH OF THE AREA OVER THE WEEKEND. A COLD FRONT WILL
REACH WESTERN WASHINGTON LATE MONDAY WITH RAIN. A COOL SHOWERY UPPER
TROUGH WILL BE OVER THE AREA TUESDAY. SHOWERS MAY PERSIST THROUGH
THE END OF NEXT WEEK.

&&

.SHORT TERM...RADAR SHOWS A FRONTAL BAND OF RAIN OVER THE OLYMPIC
PENINSULA ORIENTED ALONG A NORTH-SOUTH AXIS. THIS RAIN WILL REACH
THE SEATTLE AREA 04Z-06Z. EVERYWHERE WILL GET SOME RAIN THIS
EVENING. THE BAND IS NARROW AND PRECIPITATION WILL TURN TO SHOWERS
BY MIDNIGHT. THE SNOW LEVEL WILL FALL TO 4000 FEET OR SO AND THERE
COULD BE SEVERAL INCHES OF NEW SNOW TONIGHT ABOVE THAT LEVEL.

SHOWERS TAPER SATURDAY AND SHOULD BE CONFINED MAINLY TO THE
MOUNTAINS AND A PUGET SOUND CONVERGENCE ZONE. ONSHORE FLOW BEHIND
THE FRONT WILL BRING GALES TO THE STRAIT AND A NICE PSCZ SEEMS
LIKELY TO FORM LATE TONIGHT OVER SNOHOMISH AND KING COUNTIES. THIS
WILL DISSIPATE IN THE AFTERNOON AS WEAK UPPER RIDGING TAKES HOLD.
HIGH TEMPERATURES SATURDAY WILL BE MOSTLY IN THE 55-60 RANGE.

THE RIDGE SHOULD KEEP MOST PRECIPITATION NORTH OF THE INTERIOR AND
ON THE COAST SATURDAY NIGHT THROUGH MONDAY. SKIES WILL BE MOSTLY
CLOUDY. HIGH TEMPERATURES WILL REMAIN 55-60 ON SUNDAY WITH PERHAPS A
SKOSH OF WARMING ON MONDAY. BURKE

.LONG TERM...PREVIOUS DISCUSSION...THE GFS/ECMWF BOTH SHOW SPLIT
FLOW AND SERIES OF MOSTLY WEAK FRONTAL SYSTEMS TRAVERSING THE REGION
TUESDAY THROUGH THE END OF THE WEEK. TUESDAY LOOKS WET AND FRIDAY
LOOKS TO HAVE THE BEST CHANCE OF STAYING DRY. BUT TIMING IS NOT
LIKELY TO BE VERY RELIABLE GIVEN THE PROGRESSIVE SPLIT FLOW PATTERN.
MERCER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A COLD FRONT MOVING INTO WESTERN WASHINGTON THIS EVENING
WILL MOVE EAST OF THE CASCADES LATE TONIGHT. PRECIPITATION WILL BE
FAIRLY WIDESPREAD WITH THE FRONT AS THE AIR MASS BECOMES MOIST...
WITH WIDESPREAD SHOWERS BEHIND THE FRONT AS THE AIR MASS BECOMES
WEAKLY UNSTABLE WITH MOIST ONSHORE FLOW. THE AIR MASS WILL DRY
SOMEWHAT AT MID AND UPPER LEVELS SATURDAY AFTERNOON.

CEILINGS ACROSS THE WESTERN WASHINGTON SHOULD LOWER INTO THE 025-035
RANGE DURING THE NEXT FEW HOURS WITH AREAS OF RAIN...WHILE IFR TO
LOW END MVFR CONDITIONS CONTINUE ALONG THE COAST. CONDITIONS WILL
CHANGE LITTLE AS ONSHORE FLOW AND SHOWERS FOLLOW THE FRONT LATER
TONIGHT.

A PUGET SOUND CONVERGENCE ZONE WILL FORM LATE TONIGHT OR SATURDAY
MORNING...AND THAT FEATURE SHOULD REMAIN NORTH OF SEATTLE. ELSEWHERE
SHOWERS SHOULD DECREASE AND CONDITIONS SHOULD GRADUALLY IMPROVE ON
SATURDAY.

KSEA...SOUTH TO SOUTHWEST WIND 8-14 KT. A COLD FRONT WILL REACH
SEATTLE LATE THIS EVENING...SO RAIN WILL DEVELOP AND THEN SWITCH TO
SHOWERS OVERNIGHT. A PUGET SOUND CONVERGENCE ZONE WILL FORM BUT IT
SHOULD REMAIN NORTH OF SEATTLE. MCDONNAL

&&

.MARINE...A COLD FRONT MOVING INTO WESTERN WASHINGTON THIS EVENING
WILL MOVE EAST OF THE CASCADES LATER TONIGHT...WITH MODERATELY
STRONG ONSHORE FLOW FOLLOWING THE FRONT. THERE IS A GOOD CHANCE THAT
GALE FORCE WESTERLIES WILL DEVELOP IN THE CENTRAL AND EASTERN STRAIT
OF JUAN DE FUCA OVERNIGHT...AND WE WILL ISSUE A GALE WARNING THAT
WILL MATCH THE ONE IN EFFECT FROM PSPC VANCOUVER. SMALL CRAFT
ADVISORY WINDS SHOULD CONTINUE ALL OTHER WATERS INTO SATURDAY
MORNING.

HIGH PRESSURE WILL BUILD OVER THE REGION ON SATURDAY...WITH WINDS
EASING DURING THE DAY. AN APPROACHING FRONTAL BOUNDARY WILL BRING
SMALL CRAFT ADVISORY SOUTHERLIES TO THE COASTAL WATERS AGAIN LATER
SATURDAY THROUGH SUNDAY. A STRONG COLD FRONT SHOULD REACH THE AREA
MONDAY NIGHT.   MCDONNAL

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...GALE WARNING CENTRAL STRAIT AND EAST ENTRANCE STRAIT.
     SMALL CRAFT ADVISORY ALL OTHER WATERS.

&&

$$

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







000
FXUS66 KSEW 280325
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
830 PM PDT FRI MAR 27 2015

.SYNOPSIS...RAIN WILL DEVELOP THIS EVENING...THEN CHANGE TO SHOWERS
AFTER MIDNIGHT BEHIND A FRONT. A WEAK UPPER RIDGE WILL KEEP WEATHER
SYSTEMS MAINLY NORTH OF THE AREA OVER THE WEEKEND. A COLD FRONT WILL
REACH WESTERN WASHINGTON LATE MONDAY WITH RAIN. A COOL SHOWERY UPPER
TROUGH WILL BE OVER THE AREA TUESDAY. SHOWERS MAY PERSIST THROUGH
THE END OF NEXT WEEK.

&&

.SHORT TERM...RADAR SHOWS A FRONTAL BAND OF RAIN OVER THE OLYMPIC
PENINSULA ORIENTED ALONG A NORTH-SOUTH AXIS. THIS RAIN WILL REACH
THE SEATTLE AREA 04Z-06Z. EVERYWHERE WILL GET SOME RAIN THIS
EVENING. THE BAND IS NARROW AND PRECIPITATION WILL TURN TO SHOWERS
BY MIDNIGHT. THE SNOW LEVEL WILL FALL TO 4000 FEET OR SO AND THERE
COULD BE SEVERAL INCHES OF NEW SNOW TONIGHT ABOVE THAT LEVEL.

SHOWERS TAPER SATURDAY AND SHOULD BE CONFINED MAINLY TO THE
MOUNTAINS AND A PUGET SOUND CONVERGENCE ZONE. ONSHORE FLOW BEHIND
THE FRONT WILL BRING GALES TO THE STRAIT AND A NICE PSCZ SEEMS
LIKELY TO FORM LATE TONIGHT OVER SNOHOMISH AND KING COUNTIES. THIS
WILL DISSIPATE IN THE AFTERNOON AS WEAK UPPER RIDGING TAKES HOLD.
HIGH TEMPERATURES SATURDAY WILL BE MOSTLY IN THE 55-60 RANGE.

THE RIDGE SHOULD KEEP MOST PRECIPITATION NORTH OF THE INTERIOR AND
ON THE COAST SATURDAY NIGHT THROUGH MONDAY. SKIES WILL BE MOSTLY
CLOUDY. HIGH TEMPERATURES WILL REMAIN 55-60 ON SUNDAY WITH PERHAPS A
SKOSH OF WARMING ON MONDAY. BURKE

.LONG TERM...PREVIOUS DISCUSSION...THE GFS/ECMWF BOTH SHOW SPLIT
FLOW AND SERIES OF MOSTLY WEAK FRONTAL SYSTEMS TRAVERSING THE REGION
TUESDAY THROUGH THE END OF THE WEEK. TUESDAY LOOKS WET AND FRIDAY
LOOKS TO HAVE THE BEST CHANCE OF STAYING DRY. BUT TIMING IS NOT
LIKELY TO BE VERY RELIABLE GIVEN THE PROGRESSIVE SPLIT FLOW PATTERN.
MERCER

&&

.HYDROLOGY...FLOODING IS UNLIKELY OVER THE NEXT 7 DAYS.

&&

.AVIATION...A COLD FRONT MOVING INTO WESTERN WASHINGTON THIS EVENING
WILL MOVE EAST OF THE CASCADES LATE TONIGHT. PRECIPITATION WILL BE
FAIRLY WIDESPREAD WITH THE FRONT AS THE AIR MASS BECOMES MOIST...
WITH WIDESPREAD SHOWERS BEHIND THE FRONT AS THE AIR MASS BECOMES
WEAKLY UNSTABLE WITH MOIST ONSHORE FLOW. THE AIR MASS WILL DRY
SOMEWHAT AT MID AND UPPER LEVELS SATURDAY AFTERNOON.

CEILINGS ACROSS THE WESTERN WASHINGTON SHOULD LOWER INTO THE 025-035
RANGE DURING THE NEXT FEW HOURS WITH AREAS OF RAIN...WHILE IFR TO
LOW END MVFR CONDITIONS CONTINUE ALONG THE COAST. CONDITIONS WILL
CHANGE LITTLE AS ONSHORE FLOW AND SHOWERS FOLLOW THE FRONT LATER
TONIGHT.

A PUGET SOUND CONVERGENCE ZONE WILL FORM LATE TONIGHT OR SATURDAY
MORNING...AND THAT FEATURE SHOULD REMAIN NORTH OF SEATTLE. ELSEWHERE
SHOWERS SHOULD DECREASE AND CONDITIONS SHOULD GRADUALLY IMPROVE ON
SATURDAY.

KSEA...SOUTH TO SOUTHWEST WIND 8-14 KT. A COLD FRONT WILL REACH
SEATTLE LATE THIS EVENING...SO RAIN WILL DEVELOP AND THEN SWITCH TO
SHOWERS OVERNIGHT. A PUGET SOUND CONVERGENCE ZONE WILL FORM BUT IT
SHOULD REMAIN NORTH OF SEATTLE. MCDONNAL

&&

.MARINE...A COLD FRONT MOVING INTO WESTERN WASHINGTON THIS EVENING
WILL MOVE EAST OF THE CASCADES LATER TONIGHT...WITH MODERATELY
STRONG ONSHORE FLOW FOLLOWING THE FRONT. THERE IS A GOOD CHANCE THAT
GALE FORCE WESTERLIES WILL DEVELOP IN THE CENTRAL AND EASTERN STRAIT
OF JUAN DE FUCA OVERNIGHT...AND WE WILL ISSUE A GALE WARNING THAT
WILL MATCH THE ONE IN EFFECT FROM PSPC VANCOUVER. SMALL CRAFT
ADVISORY WINDS SHOULD CONTINUE ALL OTHER WATERS INTO SATURDAY
MORNING.

HIGH PRESSURE WILL BUILD OVER THE REGION ON SATURDAY...WITH WINDS
EASING DURING THE DAY. AN APPROACHING FRONTAL BOUNDARY WILL BRING
SMALL CRAFT ADVISORY SOUTHERLIES TO THE COASTAL WATERS AGAIN LATER
SATURDAY THROUGH SUNDAY. A STRONG COLD FRONT SHOULD REACH THE AREA
MONDAY NIGHT.   MCDONNAL

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...GALE WARNING CENTRAL STRAIT AND EAST ENTRANCE STRAIT.
     SMALL CRAFT ADVISORY ALL OTHER WATERS.

&&

$$

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






    US Dept of Commerce
    National Oceanic and Atmospheric Administration
    National Weather Service
    1325 East West Highway
    Silver Spring, MD 20910
    Page Author: NWS Internet Services Team
Disclaimer
Information Quality
Credits
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities