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000
FXUS66 KSEW 282257
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PST SAT FEB 28 2015

.SYNOPSIS...AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING ONE MORE
SUNNY DAY TO WESTERN WASHINGTON SUNDAY. A WEAK WEATHER SYSTEM WILL
MOVE THROUGH THE AREA SUNDAY NIGHT FOR A CHANCE OF LIGHT RAIN. DRY
WEATHER WILL PREVAIL FOR THE REMAINDER OF NEXT WEEK UNDER THE
INFLUENCE OF AN UPPER RIDGE AND LOW LEVEL OFFSHORE FLOW.

&&

.SHORT TERM...AN UPPER RIDGE AND LOW LEVEL OFFSHORE FLOW WILL GIVE
DRY WEATHER THROUGH SUNDAY. MODELS SHOW SOME HIGH LEVEL MOISTURE ON
SUNDAY SO THE SUNSHINE MIGHT BE FILTERED BY HIGH CLOUDS AT TIMES.

A WEAK SHORT WAVE IN THE NORTHWEST FLOW ALOFT WILL BRING A CHANCE OF
RAIN SUNDAY NIGHT. THE ECMWF IS A BIT OF AN OUTLIER...SUGGESTING AT
LEAST A LITTLE RAIN ALL AREAS BUT THIS SOLUTION IS BEING DOWNPLAYED
IN THE FORECAST FOR NOW. ALL OTHER MODELS HAVE SPOTTY AND VERY LIGHT
RAIN AT MOST WITH THE BEST CHANCES NEAR THE COAST.

THE SHORT WAVE WILL MOVE SOUTH OF THE FORECAST AREA MONDAY MORNING.
A FEW SHOWERS MAY LINGER OVER THE CASCADES OR FAR SOUTH IN THE
MORNING. OTHERWISE...IT SHOULD BE A DRY DAY WITH DECREASING CLOUDS.

AN UPPER RIDGE OVER THE EASTERN PACIFIC WILL ONCE AGAIN BE IN
CONTROL ON TUESDAY WITH LOW LEVEL OFFSHORE FLOW FOR ANOTHER DRY AND
MOSTLY SUNNY DAY. SCHNEIDER

.LONG TERM...AN UPPER RIDGE WILL BE IN CONTROL WEDNESDAY THROUGH
SATURDAY FOR A STRETCH OF DRY WEATHER. EARLIER MODELS HAD BEEN
SHOWING A WEAK SYSTEM COMING OVER THE TOP OF THE RIDGE...BRINGING A
CHANCE OF RAIN LATER IN THE WEEK...BUT NOW IT LOOKS DRY FOR THE
ENTIRE PERIOD. TEMPERATURES WILL BE NEAR NORMAL...HIGHS IN THE LOWER
TO MID 50S AND LOWS MOSTLY IN THE 30S. SCHNEIDER

&&

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

&&

.AVIATION...A LARGE UPPER LEVEL RIDGE CENTERED OVER THE NE PACIFIC
ALONG 140W WILL MAINTAIN DRY NORTHERLY FLOW OVER W WA THROUGH
SUNDAY. A SURFACE RIDGE OVER SE B.C. AND W MT WILL MAINTAIN DRY LOW
LEVEL OFFSHORE FLOW.

THE AIR MASS WILL REMAIN DRY THIS WEEKEND WITH UNRESTRICTED VFR
CONDITIONS...ALTHOUGH THERE COULD STILL BE SOME ISOLATED RIVER
VALLEY FOG DURING THE EARLY MORNING HOURS.

KSEA...UNRESTRICTED VFR THIS WEEKEND. SURFACE WINDS WILL REMAIN N
8-15 KT THROUGH 02Z THEN EASE TO 4-8 KT. KAM

&&

.MARINE...WEAK OFFSHORE FLOW WILL CONTINUE TONIGHT AND
SUNDAY...BETWEEN A SURFACE RIDGE EXTENDING FROM SE B.C. TO W
MT...AND A WEAK SURFACE TROUGH NEAR THE WA COAST.

SURFACE WINDS HAVE BEEN GRADUALLY DIMINISHING THIS AFTERNOON...BUT A
BRIEF SURGE OF NORTHERLY 15-25 KT WINDS WILL AFFECT THE COASTAL
WATERS THIS EVENING. OTHERWISE WINDS WILL REMAIN BELOW SCA LEVELS
THROUGH SUNDAY.

AN UPPER LEVEL TROUGH IS STILL EXPECTED TO MOVE SE ACROSS THE AREA
SUNDAY NIGHT. MESOSCALE MODELS STILL SHOW A BRIEF PERIOD OF SCA
LEVEL N WINDS DEVELOPING AS THE TROUGH CROSSES THE AREA.

AFTER THE UPPER LEVEL TROUGH MOVES S...ANOTHER SURFACE HIGH WILL
BUILD OVER B.C. ON MONDAY...THEN WEAKEN TUESDAY NIGHT THROUGH
WEDNESDAY. MODERATE TO POSSIBLY STRONG NE OFFSHORE FLOW WILL DEVELOP
FROM THE N INLAND WATERS...EXTENDING THROUGH THE STRAIT OF JUAN DE
FUCA AND OUT OVER THE NORTHERN COASTAL WATERS. SCA WINDS ARE
EXPECTED MONDAY NIGHT AND TUESDAY AND THERE IS SOME POTENTIAL FOR
GALE FORCE WINDS. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COASTAL ZONES 153...156...173...176.

&&

$$

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











000
FXUS66 KSEW 282257
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PST SAT FEB 28 2015

.SYNOPSIS...AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING ONE MORE
SUNNY DAY TO WESTERN WASHINGTON SUNDAY. A WEAK WEATHER SYSTEM WILL
MOVE THROUGH THE AREA SUNDAY NIGHT FOR A CHANCE OF LIGHT RAIN. DRY
WEATHER WILL PREVAIL FOR THE REMAINDER OF NEXT WEEK UNDER THE
INFLUENCE OF AN UPPER RIDGE AND LOW LEVEL OFFSHORE FLOW.

&&

.SHORT TERM...AN UPPER RIDGE AND LOW LEVEL OFFSHORE FLOW WILL GIVE
DRY WEATHER THROUGH SUNDAY. MODELS SHOW SOME HIGH LEVEL MOISTURE ON
SUNDAY SO THE SUNSHINE MIGHT BE FILTERED BY HIGH CLOUDS AT TIMES.

A WEAK SHORT WAVE IN THE NORTHWEST FLOW ALOFT WILL BRING A CHANCE OF
RAIN SUNDAY NIGHT. THE ECMWF IS A BIT OF AN OUTLIER...SUGGESTING AT
LEAST A LITTLE RAIN ALL AREAS BUT THIS SOLUTION IS BEING DOWNPLAYED
IN THE FORECAST FOR NOW. ALL OTHER MODELS HAVE SPOTTY AND VERY LIGHT
RAIN AT MOST WITH THE BEST CHANCES NEAR THE COAST.

THE SHORT WAVE WILL MOVE SOUTH OF THE FORECAST AREA MONDAY MORNING.
A FEW SHOWERS MAY LINGER OVER THE CASCADES OR FAR SOUTH IN THE
MORNING. OTHERWISE...IT SHOULD BE A DRY DAY WITH DECREASING CLOUDS.

AN UPPER RIDGE OVER THE EASTERN PACIFIC WILL ONCE AGAIN BE IN
CONTROL ON TUESDAY WITH LOW LEVEL OFFSHORE FLOW FOR ANOTHER DRY AND
MOSTLY SUNNY DAY. SCHNEIDER

.LONG TERM...AN UPPER RIDGE WILL BE IN CONTROL WEDNESDAY THROUGH
SATURDAY FOR A STRETCH OF DRY WEATHER. EARLIER MODELS HAD BEEN
SHOWING A WEAK SYSTEM COMING OVER THE TOP OF THE RIDGE...BRINGING A
CHANCE OF RAIN LATER IN THE WEEK...BUT NOW IT LOOKS DRY FOR THE
ENTIRE PERIOD. TEMPERATURES WILL BE NEAR NORMAL...HIGHS IN THE LOWER
TO MID 50S AND LOWS MOSTLY IN THE 30S. SCHNEIDER

&&

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

&&

.AVIATION...A LARGE UPPER LEVEL RIDGE CENTERED OVER THE NE PACIFIC
ALONG 140W WILL MAINTAIN DRY NORTHERLY FLOW OVER W WA THROUGH
SUNDAY. A SURFACE RIDGE OVER SE B.C. AND W MT WILL MAINTAIN DRY LOW
LEVEL OFFSHORE FLOW.

THE AIR MASS WILL REMAIN DRY THIS WEEKEND WITH UNRESTRICTED VFR
CONDITIONS...ALTHOUGH THERE COULD STILL BE SOME ISOLATED RIVER
VALLEY FOG DURING THE EARLY MORNING HOURS.

KSEA...UNRESTRICTED VFR THIS WEEKEND. SURFACE WINDS WILL REMAIN N
8-15 KT THROUGH 02Z THEN EASE TO 4-8 KT. KAM

&&

.MARINE...WEAK OFFSHORE FLOW WILL CONTINUE TONIGHT AND
SUNDAY...BETWEEN A SURFACE RIDGE EXTENDING FROM SE B.C. TO W
MT...AND A WEAK SURFACE TROUGH NEAR THE WA COAST.

SURFACE WINDS HAVE BEEN GRADUALLY DIMINISHING THIS AFTERNOON...BUT A
BRIEF SURGE OF NORTHERLY 15-25 KT WINDS WILL AFFECT THE COASTAL
WATERS THIS EVENING. OTHERWISE WINDS WILL REMAIN BELOW SCA LEVELS
THROUGH SUNDAY.

AN UPPER LEVEL TROUGH IS STILL EXPECTED TO MOVE SE ACROSS THE AREA
SUNDAY NIGHT. MESOSCALE MODELS STILL SHOW A BRIEF PERIOD OF SCA
LEVEL N WINDS DEVELOPING AS THE TROUGH CROSSES THE AREA.

AFTER THE UPPER LEVEL TROUGH MOVES S...ANOTHER SURFACE HIGH WILL
BUILD OVER B.C. ON MONDAY...THEN WEAKEN TUESDAY NIGHT THROUGH
WEDNESDAY. MODERATE TO POSSIBLY STRONG NE OFFSHORE FLOW WILL DEVELOP
FROM THE N INLAND WATERS...EXTENDING THROUGH THE STRAIT OF JUAN DE
FUCA AND OUT OVER THE NORTHERN COASTAL WATERS. SCA WINDS ARE
EXPECTED MONDAY NIGHT AND TUESDAY AND THERE IS SOME POTENTIAL FOR
GALE FORCE WINDS. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY COASTAL ZONES 153...156...173...176.

&&

$$

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










000
FXUS66 KSEW 281634
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
830 AM PST SAT FEB 28 2015

.SYNOPSIS...AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS TO WESTERN WASHINGTON THIS WEEKEND. A WEAK WEATHER
SYSTEM WILL MOVE THROUGH THE AREA SUNDAY NIGHT AND MONDAY FOR A
CHANCE OF LIGHT PRECIPITATION. DRY WEATHER WILL PREVAIL AGAIN
TUESDAY AND WEDNESDAY...AND ANOTHER WEAK SYSTEM COULD REACH THE AREA
LATE IN THE WEEK.

&&

.SHORT TERM...AN UPPER RIDGE AND LOW LEVEL OFFSHORE FLOW WILL GIVE
DRY SUNNY WEATHER THIS WEEKEND. MODELS SHOW SOME HIGH CLOUDS MOVING
INTO THE AREA TONIGHT AND SUNDAY HOWEVER. A WEAK SHORT WAVE IN THE
NORTHWEST FLOW ALOFT WILL BRING A LEAST A CHANCE OF RAIN SUNDAY
NIGHT. THE ECMWF CONTINUES TO BE WETTER WITH THIS COMPARED TO OTHER
MODELS AND SLOWER TO DRY THINGS OUT ON MONDAY. SCHNEIDER

.LONG TERM...PREVIOUS DISCUSSION...DRY NORTHERLY FLOW WILL CONTINUE
TUESDAY AND WEDNESDAY AHEAD OF AN OFFSHORE UPPER RIDGE...FOR MORE
DRY WEATHER. THE RIDGE WILL WEAKEN AND SHIFT INLAND THURSDAY...AND A
WEAK UPPER SHORTWAVE COULD BRING SOME LIGHT PRECIPITATION TO THE
AREA THURSDAY THROUGH FRIDAY.   MCDONNAL

&&

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

&&

.AVIATION...A LARGE UPPER LEVEL RIDGE CENTERED OVER THE NE PACIFIC
ALONG 140W WILL MAINTAIN DRY NORTHERLY FLOW OVER W WA THROUGH
SUNDAY. A SURFACE RIDGE OVER INTERIOR B.C. WILL MAINTAIN DRY N-NE
LOW LEVEL FLOW TODAY...ALTHOUGH WEAKENING PRESSURE GRADIENTS WILL
ALLOW LOCALLY GUSTY N-NE SURFACE WINDS TO SLOWLY DIMINISH.

THE AIR MASS WILL REMAIN DRY THIS WEEKEND WITH UNRESTRICTED VFR
CONDITIONS...ALTHOUGH THERE COULD STILL BE SOME ISOLATED RIVER
VALLEY FOG DURING THE EARLY MORNING HOURS.

KSEA...UNRESTRICTED VFR THIS WEEKEND. SURFACE WINDS WILL REMAIN N
8-15 KT TODAY. KAM

&&

.MARINE...A 1032 MB SURFACE HIGH REMAINS OVER THE INTERIOR OF B.C.
THIS MORNING WITH A WEAK SURFACE TROUGH ALONG THE B.C. AND WA
COASTS. THE OFFSHORE GRADIENTS HAVE BEEN SLOWLY WEAKENING AND SHOULD
CONTINUE TO DO SO AS THE LOW OVER CA CONTINUES MOVING S. SMALL CRAFT
ADVISORIES OVER THE INTERIOR HAVE BEEN SET TO END AT NOON TODAY
BASED ON THE WEAKENING PRESSURE GRADIENTS...CURRENT CONDITIONS...
AND THE LATEST HRRR GUIDANCE. THE SCA OVER THE COASTAL WATERS WILL
END AS PLANNED AROUND MID AFTERNOON.

THE B.C. HIGH WILL WEAKEN AND SLIDE OVER THE N ROCKIES TONIGHT
LEAVING BROAD HIGH PRESSURE EXTENDING FROM THE LARGE HIGH OVER THE
NE PACIFIC ACROSS THE PACNW TO THE HIGH OVER THE NORTHERN ROCKIES.
RELATIVE TO THE TWO SURFACE HIGHS THIS WILL LEAVE A WEAK SURFACE
TROUGH OVER THE PACNW ON SUNDAY...BUT WITH WEAK PRESSURE GRADIENTS
ACROSS THE AREA.

AN UPPER LEVEL TROUGH IS STILL EXPECTED TO MOVE SE ACROSS THE AREA
SUNDAY NIGHT. MESOSCALE MODELS STILL SHOW A BRIEF PERIOD OF SCA
LEVEL N WINDS DEVELOPING AS THE TROUGH CROSSES THE AREA.

ANOTHER SURFACE RIDGE WILL MOVE OVER INTERIOR B.C. MONDAY NIGHT AND
TUESDAY FOR ANOTHER ROUND OF MODERATE N-NE FLOW. KAM

&&

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

&&

$$

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







000
FXUS66 KSEW 281634
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
830 AM PST SAT FEB 28 2015

.SYNOPSIS...AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS TO WESTERN WASHINGTON THIS WEEKEND. A WEAK WEATHER
SYSTEM WILL MOVE THROUGH THE AREA SUNDAY NIGHT AND MONDAY FOR A
CHANCE OF LIGHT PRECIPITATION. DRY WEATHER WILL PREVAIL AGAIN
TUESDAY AND WEDNESDAY...AND ANOTHER WEAK SYSTEM COULD REACH THE AREA
LATE IN THE WEEK.

&&

.SHORT TERM...AN UPPER RIDGE AND LOW LEVEL OFFSHORE FLOW WILL GIVE
DRY SUNNY WEATHER THIS WEEKEND. MODELS SHOW SOME HIGH CLOUDS MOVING
INTO THE AREA TONIGHT AND SUNDAY HOWEVER. A WEAK SHORT WAVE IN THE
NORTHWEST FLOW ALOFT WILL BRING A LEAST A CHANCE OF RAIN SUNDAY
NIGHT. THE ECMWF CONTINUES TO BE WETTER WITH THIS COMPARED TO OTHER
MODELS AND SLOWER TO DRY THINGS OUT ON MONDAY. SCHNEIDER

.LONG TERM...PREVIOUS DISCUSSION...DRY NORTHERLY FLOW WILL CONTINUE
TUESDAY AND WEDNESDAY AHEAD OF AN OFFSHORE UPPER RIDGE...FOR MORE
DRY WEATHER. THE RIDGE WILL WEAKEN AND SHIFT INLAND THURSDAY...AND A
WEAK UPPER SHORTWAVE COULD BRING SOME LIGHT PRECIPITATION TO THE
AREA THURSDAY THROUGH FRIDAY.   MCDONNAL

&&

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

&&

.AVIATION...A LARGE UPPER LEVEL RIDGE CENTERED OVER THE NE PACIFIC
ALONG 140W WILL MAINTAIN DRY NORTHERLY FLOW OVER W WA THROUGH
SUNDAY. A SURFACE RIDGE OVER INTERIOR B.C. WILL MAINTAIN DRY N-NE
LOW LEVEL FLOW TODAY...ALTHOUGH WEAKENING PRESSURE GRADIENTS WILL
ALLOW LOCALLY GUSTY N-NE SURFACE WINDS TO SLOWLY DIMINISH.

THE AIR MASS WILL REMAIN DRY THIS WEEKEND WITH UNRESTRICTED VFR
CONDITIONS...ALTHOUGH THERE COULD STILL BE SOME ISOLATED RIVER
VALLEY FOG DURING THE EARLY MORNING HOURS.

KSEA...UNRESTRICTED VFR THIS WEEKEND. SURFACE WINDS WILL REMAIN N
8-15 KT TODAY. KAM

&&

.MARINE...A 1032 MB SURFACE HIGH REMAINS OVER THE INTERIOR OF B.C.
THIS MORNING WITH A WEAK SURFACE TROUGH ALONG THE B.C. AND WA
COASTS. THE OFFSHORE GRADIENTS HAVE BEEN SLOWLY WEAKENING AND SHOULD
CONTINUE TO DO SO AS THE LOW OVER CA CONTINUES MOVING S. SMALL CRAFT
ADVISORIES OVER THE INTERIOR HAVE BEEN SET TO END AT NOON TODAY
BASED ON THE WEAKENING PRESSURE GRADIENTS...CURRENT CONDITIONS...
AND THE LATEST HRRR GUIDANCE. THE SCA OVER THE COASTAL WATERS WILL
END AS PLANNED AROUND MID AFTERNOON.

THE B.C. HIGH WILL WEAKEN AND SLIDE OVER THE N ROCKIES TONIGHT
LEAVING BROAD HIGH PRESSURE EXTENDING FROM THE LARGE HIGH OVER THE
NE PACIFIC ACROSS THE PACNW TO THE HIGH OVER THE NORTHERN ROCKIES.
RELATIVE TO THE TWO SURFACE HIGHS THIS WILL LEAVE A WEAK SURFACE
TROUGH OVER THE PACNW ON SUNDAY...BUT WITH WEAK PRESSURE GRADIENTS
ACROSS THE AREA.

AN UPPER LEVEL TROUGH IS STILL EXPECTED TO MOVE SE ACROSS THE AREA
SUNDAY NIGHT. MESOSCALE MODELS STILL SHOW A BRIEF PERIOD OF SCA
LEVEL N WINDS DEVELOPING AS THE TROUGH CROSSES THE AREA.

ANOTHER SURFACE RIDGE WILL MOVE OVER INTERIOR B.C. MONDAY NIGHT AND
TUESDAY FOR ANOTHER ROUND OF MODERATE N-NE FLOW. KAM

&&

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

&&

$$

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








000
FXUS66 KSEW 281634
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
830 AM PST SAT FEB 28 2015

.SYNOPSIS...AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS TO WESTERN WASHINGTON THIS WEEKEND. A WEAK WEATHER
SYSTEM WILL MOVE THROUGH THE AREA SUNDAY NIGHT AND MONDAY FOR A
CHANCE OF LIGHT PRECIPITATION. DRY WEATHER WILL PREVAIL AGAIN
TUESDAY AND WEDNESDAY...AND ANOTHER WEAK SYSTEM COULD REACH THE AREA
LATE IN THE WEEK.

&&

.SHORT TERM...AN UPPER RIDGE AND LOW LEVEL OFFSHORE FLOW WILL GIVE
DRY SUNNY WEATHER THIS WEEKEND. MODELS SHOW SOME HIGH CLOUDS MOVING
INTO THE AREA TONIGHT AND SUNDAY HOWEVER. A WEAK SHORT WAVE IN THE
NORTHWEST FLOW ALOFT WILL BRING A LEAST A CHANCE OF RAIN SUNDAY
NIGHT. THE ECMWF CONTINUES TO BE WETTER WITH THIS COMPARED TO OTHER
MODELS AND SLOWER TO DRY THINGS OUT ON MONDAY. SCHNEIDER

.LONG TERM...PREVIOUS DISCUSSION...DRY NORTHERLY FLOW WILL CONTINUE
TUESDAY AND WEDNESDAY AHEAD OF AN OFFSHORE UPPER RIDGE...FOR MORE
DRY WEATHER. THE RIDGE WILL WEAKEN AND SHIFT INLAND THURSDAY...AND A
WEAK UPPER SHORTWAVE COULD BRING SOME LIGHT PRECIPITATION TO THE
AREA THURSDAY THROUGH FRIDAY.   MCDONNAL

&&

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

&&

.AVIATION...A LARGE UPPER LEVEL RIDGE CENTERED OVER THE NE PACIFIC
ALONG 140W WILL MAINTAIN DRY NORTHERLY FLOW OVER W WA THROUGH
SUNDAY. A SURFACE RIDGE OVER INTERIOR B.C. WILL MAINTAIN DRY N-NE
LOW LEVEL FLOW TODAY...ALTHOUGH WEAKENING PRESSURE GRADIENTS WILL
ALLOW LOCALLY GUSTY N-NE SURFACE WINDS TO SLOWLY DIMINISH.

THE AIR MASS WILL REMAIN DRY THIS WEEKEND WITH UNRESTRICTED VFR
CONDITIONS...ALTHOUGH THERE COULD STILL BE SOME ISOLATED RIVER
VALLEY FOG DURING THE EARLY MORNING HOURS.

KSEA...UNRESTRICTED VFR THIS WEEKEND. SURFACE WINDS WILL REMAIN N
8-15 KT TODAY. KAM

&&

.MARINE...A 1032 MB SURFACE HIGH REMAINS OVER THE INTERIOR OF B.C.
THIS MORNING WITH A WEAK SURFACE TROUGH ALONG THE B.C. AND WA
COASTS. THE OFFSHORE GRADIENTS HAVE BEEN SLOWLY WEAKENING AND SHOULD
CONTINUE TO DO SO AS THE LOW OVER CA CONTINUES MOVING S. SMALL CRAFT
ADVISORIES OVER THE INTERIOR HAVE BEEN SET TO END AT NOON TODAY
BASED ON THE WEAKENING PRESSURE GRADIENTS...CURRENT CONDITIONS...
AND THE LATEST HRRR GUIDANCE. THE SCA OVER THE COASTAL WATERS WILL
END AS PLANNED AROUND MID AFTERNOON.

THE B.C. HIGH WILL WEAKEN AND SLIDE OVER THE N ROCKIES TONIGHT
LEAVING BROAD HIGH PRESSURE EXTENDING FROM THE LARGE HIGH OVER THE
NE PACIFIC ACROSS THE PACNW TO THE HIGH OVER THE NORTHERN ROCKIES.
RELATIVE TO THE TWO SURFACE HIGHS THIS WILL LEAVE A WEAK SURFACE
TROUGH OVER THE PACNW ON SUNDAY...BUT WITH WEAK PRESSURE GRADIENTS
ACROSS THE AREA.

AN UPPER LEVEL TROUGH IS STILL EXPECTED TO MOVE SE ACROSS THE AREA
SUNDAY NIGHT. MESOSCALE MODELS STILL SHOW A BRIEF PERIOD OF SCA
LEVEL N WINDS DEVELOPING AS THE TROUGH CROSSES THE AREA.

ANOTHER SURFACE RIDGE WILL MOVE OVER INTERIOR B.C. MONDAY NIGHT AND
TUESDAY FOR ANOTHER ROUND OF MODERATE N-NE FLOW. KAM

&&

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

&&

$$

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








000
FXUS66 KSEW 281101
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 AM PST SAT FEB 28 2015

.SYNOPSIS...AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS TO WESTERN WASHINGTON THIS WEEKEND. A WEAK WEATHER
SYSTEM WILL MOVE THROUGH THE AREA SUNDAY NIGHT AND MONDAY FOR A
CHANCE OF LIGHT PRECIPITATION. DRY WEATHER WILL PREVAIL AGAIN
TUESDAY AND WEDNESDAY...AND ANOTHER WEAK SYSTEM COULD REACH THE AREA
LATE IN THE WEEK.

&&

.SHORT TERM...DRY NORTHERLY FLOW DEVELOPED OVER WESTERN WASHINGTON
OVERNIGHT WITH SKIES CLEARING FROM NORTH TO SOUTH. THE NORTHEASTERLY
PRESSURE GRADIENT HAS BEEN STRENGTHENING...AS A 1031 MB SURFACE HIGH
MOVES SOUTH THROUGH BRITISH COLUMBIA. AT 2 AM SKIES WERE CLEAR TO
PARTLY CLOUDY AND TEMPERATURES WERE IN THE MID 30S TO MID 40S.
NORTHEAST WINDS WERE LOCALLY GUSTING TO AROUND 25 MPH...MAINLY IN
THE NORTH INTERIOR NEAR THE SOURCE OF FRASER RIVER OUTFLOW.

DRY NORTHERLY FLOW ALOFT WILL CONTINUE TODAY AND TONIGHT...WITH A
STRONG UPPER RIDGE WELL OFFSHORE. TODAY WILL BE SUNNY AND TONIGHT
WILL BE CLEAR. THE NORTHEAST PRESSURE GRADIENT WILL REACH ITS PEAK
DURING THE NEXT FEW HOURS AND THEN GRADUALLY RELAX DURING THE
DAY...SO THE GUSTY NORTHEAST WINDS SHOULD EASE. WITH CLEAR SKIES...A
COOL DRY AIR MASS AND GENERALLY LIGHT WINDS TONIGHT...THE OVERNIGHT
LOWS SHOULD FALL INTO THE UPPER 20S TO MID 30S.

THE UPPER FLOW WILL BACK TO NORTHWEST ON SUNDAY...AS A WEAK UPPER
SHORTWAVE MOVES SOUTHEAST ALONG THE BRITISH COLUMBIA COAST. IT WILL
BE ANOTHER DRY DAY...BUT THE COAST WILL PROBABLY BECOME MOSTLY
CLOUDY IN THE AFTERNOON AND SOME HIGH CLOUDS WILL SHOW UP OVER THE
INTERIOR OF WESTERN WASHINGTON.

THE SHORTWAVE WILL MOVE SOUTHEAST ACROSS THE FORECAST AREA SUNDAY
NIGHT. MODELS DIFFER SOMEWHAT WITH REGARD TO HOW EXTENSIVE THE
PRECIPITATION WILL BE WITH THIS FEATURE...BUT AMOUNTS SHOULD BE
FAIRLY LIGHT. DRY NORTHERLY FLOW WILL DEVELOP AGAIN BEHIND THE
SHORTWAVE...WITH SHOWERS ENDING AND SKIES CLEARING MONDAY AND MONDAY
NIGHT.   MCDONNAL

.LONG TERM...DRY NORTHERLY FLOW WILL CONTINUE TUESDAY AND WEDNESDAY
AHEAD OF AN OFFSHORE UPPER RIDGE...FOR MORE DRY WEATHER. THE RIDGE
WILL WEAKEN AND SHIFT INLAND THURSDAY...AND A WEAK UPPER SHORTWAVE
COULD BRING SOME LIGHT PRECIPITATION TO THE AREA THURSDAY THROUGH
FRIDAY.   MCDONNAL

&&

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

&&

.AVIATION...AN UPPER LEVEL LOW IS DEPARTING SOUTH THIS MORNING INTO
CA. THE FLOW ALOFT IS NORTHERLY. MEANWHILE DRY OFFSHORE WINDS ARE
SCOURING OUT THE LOW LEVEL MOISTURE FOR CLEARING SKIES. PATCHY FOG
IS POSSIBLE IN THE SOUTH SOUND THIS MORNING...OTHERWISE VFR
CONDITIONS WILL PREVAIL. 33

KSEA...N WINDS TODAY 08-12 KT. CLEAR SKIES WITH VFR CONDITIONS. 33

&&

.MARINE...MODERATE NORTH TO NORTHEAST FLOW CONTINUES ACROSS WESTERN
WA THIS MORNING WITH HIGH PRES OVER INTERIOR B.C. AND LOW PRES OVER
OREGON. WINDS WILL GRADUAL EASE THIS AFTERNOON THEN TURN EASTERLY.
HIGH PRESSURE OVER INTERIOR B.C. WILL MAINTAIN OFFSHORE TONIGHT INTO
SUNDAY. A WEAK SURFACE TROUGH WILL CROSS THE WATERS SUN NIGHT.
MODERATE NORTH TO NE FLOW WILL DEVELOP MONDAY NIGHT THROUGH TUESDAY
AS ANOTHER SURFACE RIDGE BUILDS OVER B.C. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS.

&&

$$

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








000
FXUS66 KSEW 281101
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 AM PST SAT FEB 28 2015

.SYNOPSIS...AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS TO WESTERN WASHINGTON THIS WEEKEND. A WEAK WEATHER
SYSTEM WILL MOVE THROUGH THE AREA SUNDAY NIGHT AND MONDAY FOR A
CHANCE OF LIGHT PRECIPITATION. DRY WEATHER WILL PREVAIL AGAIN
TUESDAY AND WEDNESDAY...AND ANOTHER WEAK SYSTEM COULD REACH THE AREA
LATE IN THE WEEK.

&&

.SHORT TERM...DRY NORTHERLY FLOW DEVELOPED OVER WESTERN WASHINGTON
OVERNIGHT WITH SKIES CLEARING FROM NORTH TO SOUTH. THE NORTHEASTERLY
PRESSURE GRADIENT HAS BEEN STRENGTHENING...AS A 1031 MB SURFACE HIGH
MOVES SOUTH THROUGH BRITISH COLUMBIA. AT 2 AM SKIES WERE CLEAR TO
PARTLY CLOUDY AND TEMPERATURES WERE IN THE MID 30S TO MID 40S.
NORTHEAST WINDS WERE LOCALLY GUSTING TO AROUND 25 MPH...MAINLY IN
THE NORTH INTERIOR NEAR THE SOURCE OF FRASER RIVER OUTFLOW.

DRY NORTHERLY FLOW ALOFT WILL CONTINUE TODAY AND TONIGHT...WITH A
STRONG UPPER RIDGE WELL OFFSHORE. TODAY WILL BE SUNNY AND TONIGHT
WILL BE CLEAR. THE NORTHEAST PRESSURE GRADIENT WILL REACH ITS PEAK
DURING THE NEXT FEW HOURS AND THEN GRADUALLY RELAX DURING THE
DAY...SO THE GUSTY NORTHEAST WINDS SHOULD EASE. WITH CLEAR SKIES...A
COOL DRY AIR MASS AND GENERALLY LIGHT WINDS TONIGHT...THE OVERNIGHT
LOWS SHOULD FALL INTO THE UPPER 20S TO MID 30S.

THE UPPER FLOW WILL BACK TO NORTHWEST ON SUNDAY...AS A WEAK UPPER
SHORTWAVE MOVES SOUTHEAST ALONG THE BRITISH COLUMBIA COAST. IT WILL
BE ANOTHER DRY DAY...BUT THE COAST WILL PROBABLY BECOME MOSTLY
CLOUDY IN THE AFTERNOON AND SOME HIGH CLOUDS WILL SHOW UP OVER THE
INTERIOR OF WESTERN WASHINGTON.

THE SHORTWAVE WILL MOVE SOUTHEAST ACROSS THE FORECAST AREA SUNDAY
NIGHT. MODELS DIFFER SOMEWHAT WITH REGARD TO HOW EXTENSIVE THE
PRECIPITATION WILL BE WITH THIS FEATURE...BUT AMOUNTS SHOULD BE
FAIRLY LIGHT. DRY NORTHERLY FLOW WILL DEVELOP AGAIN BEHIND THE
SHORTWAVE...WITH SHOWERS ENDING AND SKIES CLEARING MONDAY AND MONDAY
NIGHT.   MCDONNAL

.LONG TERM...DRY NORTHERLY FLOW WILL CONTINUE TUESDAY AND WEDNESDAY
AHEAD OF AN OFFSHORE UPPER RIDGE...FOR MORE DRY WEATHER. THE RIDGE
WILL WEAKEN AND SHIFT INLAND THURSDAY...AND A WEAK UPPER SHORTWAVE
COULD BRING SOME LIGHT PRECIPITATION TO THE AREA THURSDAY THROUGH
FRIDAY.   MCDONNAL

&&

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

&&

.AVIATION...AN UPPER LEVEL LOW IS DEPARTING SOUTH THIS MORNING INTO
CA. THE FLOW ALOFT IS NORTHERLY. MEANWHILE DRY OFFSHORE WINDS ARE
SCOURING OUT THE LOW LEVEL MOISTURE FOR CLEARING SKIES. PATCHY FOG
IS POSSIBLE IN THE SOUTH SOUND THIS MORNING...OTHERWISE VFR
CONDITIONS WILL PREVAIL. 33

KSEA...N WINDS TODAY 08-12 KT. CLEAR SKIES WITH VFR CONDITIONS. 33

&&

.MARINE...MODERATE NORTH TO NORTHEAST FLOW CONTINUES ACROSS WESTERN
WA THIS MORNING WITH HIGH PRES OVER INTERIOR B.C. AND LOW PRES OVER
OREGON. WINDS WILL GRADUAL EASE THIS AFTERNOON THEN TURN EASTERLY.
HIGH PRESSURE OVER INTERIOR B.C. WILL MAINTAIN OFFSHORE TONIGHT INTO
SUNDAY. A WEAK SURFACE TROUGH WILL CROSS THE WATERS SUN NIGHT.
MODERATE NORTH TO NE FLOW WILL DEVELOP MONDAY NIGHT THROUGH TUESDAY
AS ANOTHER SURFACE RIDGE BUILDS OVER B.C. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS.

&&

$$

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







000
FXUS66 KSEW 281101
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 AM PST SAT FEB 28 2015

.SYNOPSIS...AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS TO WESTERN WASHINGTON THIS WEEKEND. A WEAK WEATHER
SYSTEM WILL MOVE THROUGH THE AREA SUNDAY NIGHT AND MONDAY FOR A
CHANCE OF LIGHT PRECIPITATION. DRY WEATHER WILL PREVAIL AGAIN
TUESDAY AND WEDNESDAY...AND ANOTHER WEAK SYSTEM COULD REACH THE AREA
LATE IN THE WEEK.

&&

.SHORT TERM...DRY NORTHERLY FLOW DEVELOPED OVER WESTERN WASHINGTON
OVERNIGHT WITH SKIES CLEARING FROM NORTH TO SOUTH. THE NORTHEASTERLY
PRESSURE GRADIENT HAS BEEN STRENGTHENING...AS A 1031 MB SURFACE HIGH
MOVES SOUTH THROUGH BRITISH COLUMBIA. AT 2 AM SKIES WERE CLEAR TO
PARTLY CLOUDY AND TEMPERATURES WERE IN THE MID 30S TO MID 40S.
NORTHEAST WINDS WERE LOCALLY GUSTING TO AROUND 25 MPH...MAINLY IN
THE NORTH INTERIOR NEAR THE SOURCE OF FRASER RIVER OUTFLOW.

DRY NORTHERLY FLOW ALOFT WILL CONTINUE TODAY AND TONIGHT...WITH A
STRONG UPPER RIDGE WELL OFFSHORE. TODAY WILL BE SUNNY AND TONIGHT
WILL BE CLEAR. THE NORTHEAST PRESSURE GRADIENT WILL REACH ITS PEAK
DURING THE NEXT FEW HOURS AND THEN GRADUALLY RELAX DURING THE
DAY...SO THE GUSTY NORTHEAST WINDS SHOULD EASE. WITH CLEAR SKIES...A
COOL DRY AIR MASS AND GENERALLY LIGHT WINDS TONIGHT...THE OVERNIGHT
LOWS SHOULD FALL INTO THE UPPER 20S TO MID 30S.

THE UPPER FLOW WILL BACK TO NORTHWEST ON SUNDAY...AS A WEAK UPPER
SHORTWAVE MOVES SOUTHEAST ALONG THE BRITISH COLUMBIA COAST. IT WILL
BE ANOTHER DRY DAY...BUT THE COAST WILL PROBABLY BECOME MOSTLY
CLOUDY IN THE AFTERNOON AND SOME HIGH CLOUDS WILL SHOW UP OVER THE
INTERIOR OF WESTERN WASHINGTON.

THE SHORTWAVE WILL MOVE SOUTHEAST ACROSS THE FORECAST AREA SUNDAY
NIGHT. MODELS DIFFER SOMEWHAT WITH REGARD TO HOW EXTENSIVE THE
PRECIPITATION WILL BE WITH THIS FEATURE...BUT AMOUNTS SHOULD BE
FAIRLY LIGHT. DRY NORTHERLY FLOW WILL DEVELOP AGAIN BEHIND THE
SHORTWAVE...WITH SHOWERS ENDING AND SKIES CLEARING MONDAY AND MONDAY
NIGHT.   MCDONNAL

.LONG TERM...DRY NORTHERLY FLOW WILL CONTINUE TUESDAY AND WEDNESDAY
AHEAD OF AN OFFSHORE UPPER RIDGE...FOR MORE DRY WEATHER. THE RIDGE
WILL WEAKEN AND SHIFT INLAND THURSDAY...AND A WEAK UPPER SHORTWAVE
COULD BRING SOME LIGHT PRECIPITATION TO THE AREA THURSDAY THROUGH
FRIDAY.   MCDONNAL

&&

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

&&

.AVIATION...AN UPPER LEVEL LOW IS DEPARTING SOUTH THIS MORNING INTO
CA. THE FLOW ALOFT IS NORTHERLY. MEANWHILE DRY OFFSHORE WINDS ARE
SCOURING OUT THE LOW LEVEL MOISTURE FOR CLEARING SKIES. PATCHY FOG
IS POSSIBLE IN THE SOUTH SOUND THIS MORNING...OTHERWISE VFR
CONDITIONS WILL PREVAIL. 33

KSEA...N WINDS TODAY 08-12 KT. CLEAR SKIES WITH VFR CONDITIONS. 33

&&

.MARINE...MODERATE NORTH TO NORTHEAST FLOW CONTINUES ACROSS WESTERN
WA THIS MORNING WITH HIGH PRES OVER INTERIOR B.C. AND LOW PRES OVER
OREGON. WINDS WILL GRADUAL EASE THIS AFTERNOON THEN TURN EASTERLY.
HIGH PRESSURE OVER INTERIOR B.C. WILL MAINTAIN OFFSHORE TONIGHT INTO
SUNDAY. A WEAK SURFACE TROUGH WILL CROSS THE WATERS SUN NIGHT.
MODERATE NORTH TO NE FLOW WILL DEVELOP MONDAY NIGHT THROUGH TUESDAY
AS ANOTHER SURFACE RIDGE BUILDS OVER B.C. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS.

&&

$$

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







000
FXUS66 KSEW 281101
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 AM PST SAT FEB 28 2015

.SYNOPSIS...AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS TO WESTERN WASHINGTON THIS WEEKEND. A WEAK WEATHER
SYSTEM WILL MOVE THROUGH THE AREA SUNDAY NIGHT AND MONDAY FOR A
CHANCE OF LIGHT PRECIPITATION. DRY WEATHER WILL PREVAIL AGAIN
TUESDAY AND WEDNESDAY...AND ANOTHER WEAK SYSTEM COULD REACH THE AREA
LATE IN THE WEEK.

&&

.SHORT TERM...DRY NORTHERLY FLOW DEVELOPED OVER WESTERN WASHINGTON
OVERNIGHT WITH SKIES CLEARING FROM NORTH TO SOUTH. THE NORTHEASTERLY
PRESSURE GRADIENT HAS BEEN STRENGTHENING...AS A 1031 MB SURFACE HIGH
MOVES SOUTH THROUGH BRITISH COLUMBIA. AT 2 AM SKIES WERE CLEAR TO
PARTLY CLOUDY AND TEMPERATURES WERE IN THE MID 30S TO MID 40S.
NORTHEAST WINDS WERE LOCALLY GUSTING TO AROUND 25 MPH...MAINLY IN
THE NORTH INTERIOR NEAR THE SOURCE OF FRASER RIVER OUTFLOW.

DRY NORTHERLY FLOW ALOFT WILL CONTINUE TODAY AND TONIGHT...WITH A
STRONG UPPER RIDGE WELL OFFSHORE. TODAY WILL BE SUNNY AND TONIGHT
WILL BE CLEAR. THE NORTHEAST PRESSURE GRADIENT WILL REACH ITS PEAK
DURING THE NEXT FEW HOURS AND THEN GRADUALLY RELAX DURING THE
DAY...SO THE GUSTY NORTHEAST WINDS SHOULD EASE. WITH CLEAR SKIES...A
COOL DRY AIR MASS AND GENERALLY LIGHT WINDS TONIGHT...THE OVERNIGHT
LOWS SHOULD FALL INTO THE UPPER 20S TO MID 30S.

THE UPPER FLOW WILL BACK TO NORTHWEST ON SUNDAY...AS A WEAK UPPER
SHORTWAVE MOVES SOUTHEAST ALONG THE BRITISH COLUMBIA COAST. IT WILL
BE ANOTHER DRY DAY...BUT THE COAST WILL PROBABLY BECOME MOSTLY
CLOUDY IN THE AFTERNOON AND SOME HIGH CLOUDS WILL SHOW UP OVER THE
INTERIOR OF WESTERN WASHINGTON.

THE SHORTWAVE WILL MOVE SOUTHEAST ACROSS THE FORECAST AREA SUNDAY
NIGHT. MODELS DIFFER SOMEWHAT WITH REGARD TO HOW EXTENSIVE THE
PRECIPITATION WILL BE WITH THIS FEATURE...BUT AMOUNTS SHOULD BE
FAIRLY LIGHT. DRY NORTHERLY FLOW WILL DEVELOP AGAIN BEHIND THE
SHORTWAVE...WITH SHOWERS ENDING AND SKIES CLEARING MONDAY AND MONDAY
NIGHT.   MCDONNAL

.LONG TERM...DRY NORTHERLY FLOW WILL CONTINUE TUESDAY AND WEDNESDAY
AHEAD OF AN OFFSHORE UPPER RIDGE...FOR MORE DRY WEATHER. THE RIDGE
WILL WEAKEN AND SHIFT INLAND THURSDAY...AND A WEAK UPPER SHORTWAVE
COULD BRING SOME LIGHT PRECIPITATION TO THE AREA THURSDAY THROUGH
FRIDAY.   MCDONNAL

&&

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

&&

.AVIATION...AN UPPER LEVEL LOW IS DEPARTING SOUTH THIS MORNING INTO
CA. THE FLOW ALOFT IS NORTHERLY. MEANWHILE DRY OFFSHORE WINDS ARE
SCOURING OUT THE LOW LEVEL MOISTURE FOR CLEARING SKIES. PATCHY FOG
IS POSSIBLE IN THE SOUTH SOUND THIS MORNING...OTHERWISE VFR
CONDITIONS WILL PREVAIL. 33

KSEA...N WINDS TODAY 08-12 KT. CLEAR SKIES WITH VFR CONDITIONS. 33

&&

.MARINE...MODERATE NORTH TO NORTHEAST FLOW CONTINUES ACROSS WESTERN
WA THIS MORNING WITH HIGH PRES OVER INTERIOR B.C. AND LOW PRES OVER
OREGON. WINDS WILL GRADUAL EASE THIS AFTERNOON THEN TURN EASTERLY.
HIGH PRESSURE OVER INTERIOR B.C. WILL MAINTAIN OFFSHORE TONIGHT INTO
SUNDAY. A WEAK SURFACE TROUGH WILL CROSS THE WATERS SUN NIGHT.
MODERATE NORTH TO NE FLOW WILL DEVELOP MONDAY NIGHT THROUGH TUESDAY
AS ANOTHER SURFACE RIDGE BUILDS OVER B.C. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS.

&&

$$

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








000
FXUS66 KSEW 280542
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
940 PM PST FRI FEB 27 2015

.SYNOPSIS...NORTHERLY FLOW ALOFT AND LOW LEVEL OFFSHORE FLOW HAVE
DEVELOPED AND ARE USHERING A MUCH DRIER AIR MASS INTO WESTERN
WASHINGTON TONIGHT. AS A RESULT...SHOWERS HAVE TAPERED OFF...AND
SKIES WILL CONTINUE CLEARING OVERNIGHT. A WEAK SYSTEM WILL MOVE
THROUGH SUNDAY NIGHT AND MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND
WEDNESDAY.

&&

.SHORT TERM...UPPER LOW OVER OVER NW ORE THIS EVNG MOVE SOUTH TO THE
BAY AREA BY LATE SAT...ALLOWING A LONGWAVE RIDGE AXIS NEAR 140W TO
EXPAND INTO THE PAC NW. SFC HIGH PRES HAS ALREADY SETTLED INTO THE
INTERIOR OF B.C...WITH THE KBLI-CYWL GRADIENT GETTING AS STRONG AS
-12 MB AS OF 03Z. AS A RESULT...A SHORT-LIVED FRASER OUTFLOW EVENT
IS UNDERWAY. THE AIR MASS COMING OUT OF B.C. IS NOT TERRIBLY COLD.
HOWEVER...THE AIR MASS IS DRY...WITH THE DEWPOINT AT KBLI NOW DOWN
TO 23F. DRIER AIR AND LARGE-SCALE SUBSIDENCE WILL SPREAD ACROSS THE
FCST AREA OVERNIGHT AND EARLY SAT MRNG...CAUSING THE FEW REMAINING
SPRINKLES TO DISSIPATE WITH SKIES CLEARING FROM NORTH TO SOUTH.

HIGH PRESSURE OVER B.C. WILL MOVE OUT EAST OF THE ROCKIES ON
SUNDAY...WITH PRESSURE GRADIENTS OVER WRN WA RELAXING ON SAT NGT.
WINDS WILL BECOME MUCH LIGHTER.

THE FLOW ALOFT WILL BACK TO NW ON SUNDAY AS A WEATHER SYSTEM
APPROACHES FROM THE NORTHWEST. THIS WEATHER SYSTEM WILL DROP DOWN
FROM THE NW SUN NIGHT AND MON...BRINGING CLOUDS. THE ECMWF AND NAM
SHOW RAIN ALL AREAS WITH THIS FEATURE BUT THE GFS JUST HAS SPOTTY
PRECIPITATION AND THE GEM IS DRY. THE FORECAST IS A BLEND OF THESE
MODELS FOR NOW WHICH MEANS MOSTLY CLOUDY WITH A CHANCE OF RAIN.
HANER

.LONG TERM...FROM PREVIOUS DISCUSSION...AN UPPER RIDGE WILL BE OVER
THE NORTHEAST PACIFIC TUESDAY AND WEDNESDAY...GIVING DRY NORTHERLY
FLOW ALOFT TO WESTERN WASHINGTON. THERE WILL BE SOME BREEZY NORTH
WINDS TUESDAY AS A SURFACE HIGH MOVES INTO SOUTHERN BRITISH
COLUMBIA...THEN LESS WIND WEDNESDAY AS THE HIGH SHIFTS SOUTHEAST.

MODELS SHOW THE UPPER RIDGE WEAKENING A BIT THURSDAY WITH A WARM
FRONT MOVING OVER THE TOP. THIS WILL BRING SOME CLOUDS TO THE AREA
AND PERHAPS A CHANCE OF RAIN...WITH THE BEST CHANCES COAST AND FAR
NORTH. A COLD FRONT WILL APPROACH FROM THE WEST ON FRIDAY. THIS DAY
COULD WIND UP BEING DRY BUT A CHANCE OF RAIN CANNOT BE COMPLETELY
RULED OUT FOR NOW. SCHNEIDER

&&

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

&&

.AVIATION...AN UPPER LEVEL LOW OVER OREGON WILL CONTINUE TRACKING
SOUTH TONIGHT. THE FLOW ALOFT OVER WESTERN WA IS NORTHERLY. LIGHT
SHOWERS ARE LIMITED TO THE SOUTHERN PORTION OF THE CWA THIS
EVENING...MAINLY SOUTH OF SEATAC AS THIS SYSTEM PULLS FARTHER SOUTH.
MEANWHILE MODERATE NORTH TO NE SURFACE WINDS WILL SCOUR OUT THE LOW
LEVEL CLOUDS WITH SKIES BECOMING CLEAR FROM NORTH TO SOUTH TONIGHT.
ALTHOUGH KCLM WILL SEE A CEILING WITH NE UPSLOPE WINDS. PATCHY
SHALLOW FOG WILL BE LIMITED TO KOLM OVERNIGHT. EXPECT VFR CONDITIONS
ON SAT WITH OFFSHORE FLOW. 33

KSEA...N WINDS WILL PREVAIL TONIGHT TO 10-15 KT. SKIES CLEARING BY
09Z WITH VFR CONDITIONS EXPECTED. 33

&&

.MARINE...NORTH TO NORTHEAST FLOW WILL CONTINUE ACROSS WESTERN WA
TONIGHT AS A 1008 MB SURFACE LOW TRACKS SOUTH ALONG THE SOUTHERN
OREGON COAST. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL WATERS.
HIGH PRESSURE OVER INTERIOR B.C. WILL MAINTAIN OFFSHORE ON SATURDAY.
A WEAK SURFACE TROUGH WILL CROSS THE WATERS ON SUN FOR BRIEF ONSHORE
WINDS. NORTH TO NE FLOW WILL DEVELOP MONDAY NIGHT THROUGH TUESDAY AS
ANOTHER SURFACE RIDGE BUILDS OVER B.C. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS.

&&

$$

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






000
FXUS66 KSEW 280542
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
940 PM PST FRI FEB 27 2015

.SYNOPSIS...NORTHERLY FLOW ALOFT AND LOW LEVEL OFFSHORE FLOW HAVE
DEVELOPED AND ARE USHERING A MUCH DRIER AIR MASS INTO WESTERN
WASHINGTON TONIGHT. AS A RESULT...SHOWERS HAVE TAPERED OFF...AND
SKIES WILL CONTINUE CLEARING OVERNIGHT. A WEAK SYSTEM WILL MOVE
THROUGH SUNDAY NIGHT AND MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND
WEDNESDAY.

&&

.SHORT TERM...UPPER LOW OVER OVER NW ORE THIS EVNG MOVE SOUTH TO THE
BAY AREA BY LATE SAT...ALLOWING A LONGWAVE RIDGE AXIS NEAR 140W TO
EXPAND INTO THE PAC NW. SFC HIGH PRES HAS ALREADY SETTLED INTO THE
INTERIOR OF B.C...WITH THE KBLI-CYWL GRADIENT GETTING AS STRONG AS
-12 MB AS OF 03Z. AS A RESULT...A SHORT-LIVED FRASER OUTFLOW EVENT
IS UNDERWAY. THE AIR MASS COMING OUT OF B.C. IS NOT TERRIBLY COLD.
HOWEVER...THE AIR MASS IS DRY...WITH THE DEWPOINT AT KBLI NOW DOWN
TO 23F. DRIER AIR AND LARGE-SCALE SUBSIDENCE WILL SPREAD ACROSS THE
FCST AREA OVERNIGHT AND EARLY SAT MRNG...CAUSING THE FEW REMAINING
SPRINKLES TO DISSIPATE WITH SKIES CLEARING FROM NORTH TO SOUTH.

HIGH PRESSURE OVER B.C. WILL MOVE OUT EAST OF THE ROCKIES ON
SUNDAY...WITH PRESSURE GRADIENTS OVER WRN WA RELAXING ON SAT NGT.
WINDS WILL BECOME MUCH LIGHTER.

THE FLOW ALOFT WILL BACK TO NW ON SUNDAY AS A WEATHER SYSTEM
APPROACHES FROM THE NORTHWEST. THIS WEATHER SYSTEM WILL DROP DOWN
FROM THE NW SUN NIGHT AND MON...BRINGING CLOUDS. THE ECMWF AND NAM
SHOW RAIN ALL AREAS WITH THIS FEATURE BUT THE GFS JUST HAS SPOTTY
PRECIPITATION AND THE GEM IS DRY. THE FORECAST IS A BLEND OF THESE
MODELS FOR NOW WHICH MEANS MOSTLY CLOUDY WITH A CHANCE OF RAIN.
HANER

.LONG TERM...FROM PREVIOUS DISCUSSION...AN UPPER RIDGE WILL BE OVER
THE NORTHEAST PACIFIC TUESDAY AND WEDNESDAY...GIVING DRY NORTHERLY
FLOW ALOFT TO WESTERN WASHINGTON. THERE WILL BE SOME BREEZY NORTH
WINDS TUESDAY AS A SURFACE HIGH MOVES INTO SOUTHERN BRITISH
COLUMBIA...THEN LESS WIND WEDNESDAY AS THE HIGH SHIFTS SOUTHEAST.

MODELS SHOW THE UPPER RIDGE WEAKENING A BIT THURSDAY WITH A WARM
FRONT MOVING OVER THE TOP. THIS WILL BRING SOME CLOUDS TO THE AREA
AND PERHAPS A CHANCE OF RAIN...WITH THE BEST CHANCES COAST AND FAR
NORTH. A COLD FRONT WILL APPROACH FROM THE WEST ON FRIDAY. THIS DAY
COULD WIND UP BEING DRY BUT A CHANCE OF RAIN CANNOT BE COMPLETELY
RULED OUT FOR NOW. SCHNEIDER

&&

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

&&

.AVIATION...AN UPPER LEVEL LOW OVER OREGON WILL CONTINUE TRACKING
SOUTH TONIGHT. THE FLOW ALOFT OVER WESTERN WA IS NORTHERLY. LIGHT
SHOWERS ARE LIMITED TO THE SOUTHERN PORTION OF THE CWA THIS
EVENING...MAINLY SOUTH OF SEATAC AS THIS SYSTEM PULLS FARTHER SOUTH.
MEANWHILE MODERATE NORTH TO NE SURFACE WINDS WILL SCOUR OUT THE LOW
LEVEL CLOUDS WITH SKIES BECOMING CLEAR FROM NORTH TO SOUTH TONIGHT.
ALTHOUGH KCLM WILL SEE A CEILING WITH NE UPSLOPE WINDS. PATCHY
SHALLOW FOG WILL BE LIMITED TO KOLM OVERNIGHT. EXPECT VFR CONDITIONS
ON SAT WITH OFFSHORE FLOW. 33

KSEA...N WINDS WILL PREVAIL TONIGHT TO 10-15 KT. SKIES CLEARING BY
09Z WITH VFR CONDITIONS EXPECTED. 33

&&

.MARINE...NORTH TO NORTHEAST FLOW WILL CONTINUE ACROSS WESTERN WA
TONIGHT AS A 1008 MB SURFACE LOW TRACKS SOUTH ALONG THE SOUTHERN
OREGON COAST. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL WATERS.
HIGH PRESSURE OVER INTERIOR B.C. WILL MAINTAIN OFFSHORE ON SATURDAY.
A WEAK SURFACE TROUGH WILL CROSS THE WATERS ON SUN FOR BRIEF ONSHORE
WINDS. NORTH TO NE FLOW WILL DEVELOP MONDAY NIGHT THROUGH TUESDAY AS
ANOTHER SURFACE RIDGE BUILDS OVER B.C. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS.

&&

$$

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







000
FXUS66 KSEW 280542
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
940 PM PST FRI FEB 27 2015

.SYNOPSIS...NORTHERLY FLOW ALOFT AND LOW LEVEL OFFSHORE FLOW HAVE
DEVELOPED AND ARE USHERING A MUCH DRIER AIR MASS INTO WESTERN
WASHINGTON TONIGHT. AS A RESULT...SHOWERS HAVE TAPERED OFF...AND
SKIES WILL CONTINUE CLEARING OVERNIGHT. A WEAK SYSTEM WILL MOVE
THROUGH SUNDAY NIGHT AND MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND
WEDNESDAY.

&&

.SHORT TERM...UPPER LOW OVER OVER NW ORE THIS EVNG MOVE SOUTH TO THE
BAY AREA BY LATE SAT...ALLOWING A LONGWAVE RIDGE AXIS NEAR 140W TO
EXPAND INTO THE PAC NW. SFC HIGH PRES HAS ALREADY SETTLED INTO THE
INTERIOR OF B.C...WITH THE KBLI-CYWL GRADIENT GETTING AS STRONG AS
-12 MB AS OF 03Z. AS A RESULT...A SHORT-LIVED FRASER OUTFLOW EVENT
IS UNDERWAY. THE AIR MASS COMING OUT OF B.C. IS NOT TERRIBLY COLD.
HOWEVER...THE AIR MASS IS DRY...WITH THE DEWPOINT AT KBLI NOW DOWN
TO 23F. DRIER AIR AND LARGE-SCALE SUBSIDENCE WILL SPREAD ACROSS THE
FCST AREA OVERNIGHT AND EARLY SAT MRNG...CAUSING THE FEW REMAINING
SPRINKLES TO DISSIPATE WITH SKIES CLEARING FROM NORTH TO SOUTH.

HIGH PRESSURE OVER B.C. WILL MOVE OUT EAST OF THE ROCKIES ON
SUNDAY...WITH PRESSURE GRADIENTS OVER WRN WA RELAXING ON SAT NGT.
WINDS WILL BECOME MUCH LIGHTER.

THE FLOW ALOFT WILL BACK TO NW ON SUNDAY AS A WEATHER SYSTEM
APPROACHES FROM THE NORTHWEST. THIS WEATHER SYSTEM WILL DROP DOWN
FROM THE NW SUN NIGHT AND MON...BRINGING CLOUDS. THE ECMWF AND NAM
SHOW RAIN ALL AREAS WITH THIS FEATURE BUT THE GFS JUST HAS SPOTTY
PRECIPITATION AND THE GEM IS DRY. THE FORECAST IS A BLEND OF THESE
MODELS FOR NOW WHICH MEANS MOSTLY CLOUDY WITH A CHANCE OF RAIN.
HANER

.LONG TERM...FROM PREVIOUS DISCUSSION...AN UPPER RIDGE WILL BE OVER
THE NORTHEAST PACIFIC TUESDAY AND WEDNESDAY...GIVING DRY NORTHERLY
FLOW ALOFT TO WESTERN WASHINGTON. THERE WILL BE SOME BREEZY NORTH
WINDS TUESDAY AS A SURFACE HIGH MOVES INTO SOUTHERN BRITISH
COLUMBIA...THEN LESS WIND WEDNESDAY AS THE HIGH SHIFTS SOUTHEAST.

MODELS SHOW THE UPPER RIDGE WEAKENING A BIT THURSDAY WITH A WARM
FRONT MOVING OVER THE TOP. THIS WILL BRING SOME CLOUDS TO THE AREA
AND PERHAPS A CHANCE OF RAIN...WITH THE BEST CHANCES COAST AND FAR
NORTH. A COLD FRONT WILL APPROACH FROM THE WEST ON FRIDAY. THIS DAY
COULD WIND UP BEING DRY BUT A CHANCE OF RAIN CANNOT BE COMPLETELY
RULED OUT FOR NOW. SCHNEIDER

&&

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

&&

.AVIATION...AN UPPER LEVEL LOW OVER OREGON WILL CONTINUE TRACKING
SOUTH TONIGHT. THE FLOW ALOFT OVER WESTERN WA IS NORTHERLY. LIGHT
SHOWERS ARE LIMITED TO THE SOUTHERN PORTION OF THE CWA THIS
EVENING...MAINLY SOUTH OF SEATAC AS THIS SYSTEM PULLS FARTHER SOUTH.
MEANWHILE MODERATE NORTH TO NE SURFACE WINDS WILL SCOUR OUT THE LOW
LEVEL CLOUDS WITH SKIES BECOMING CLEAR FROM NORTH TO SOUTH TONIGHT.
ALTHOUGH KCLM WILL SEE A CEILING WITH NE UPSLOPE WINDS. PATCHY
SHALLOW FOG WILL BE LIMITED TO KOLM OVERNIGHT. EXPECT VFR CONDITIONS
ON SAT WITH OFFSHORE FLOW. 33

KSEA...N WINDS WILL PREVAIL TONIGHT TO 10-15 KT. SKIES CLEARING BY
09Z WITH VFR CONDITIONS EXPECTED. 33

&&

.MARINE...NORTH TO NORTHEAST FLOW WILL CONTINUE ACROSS WESTERN WA
TONIGHT AS A 1008 MB SURFACE LOW TRACKS SOUTH ALONG THE SOUTHERN
OREGON COAST. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL WATERS.
HIGH PRESSURE OVER INTERIOR B.C. WILL MAINTAIN OFFSHORE ON SATURDAY.
A WEAK SURFACE TROUGH WILL CROSS THE WATERS ON SUN FOR BRIEF ONSHORE
WINDS. NORTH TO NE FLOW WILL DEVELOP MONDAY NIGHT THROUGH TUESDAY AS
ANOTHER SURFACE RIDGE BUILDS OVER B.C. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS.

&&

$$

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






000
FXUS66 KSEW 280542
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
940 PM PST FRI FEB 27 2015

.SYNOPSIS...NORTHERLY FLOW ALOFT AND LOW LEVEL OFFSHORE FLOW HAVE
DEVELOPED AND ARE USHERING A MUCH DRIER AIR MASS INTO WESTERN
WASHINGTON TONIGHT. AS A RESULT...SHOWERS HAVE TAPERED OFF...AND
SKIES WILL CONTINUE CLEARING OVERNIGHT. A WEAK SYSTEM WILL MOVE
THROUGH SUNDAY NIGHT AND MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND
WEDNESDAY.

&&

.SHORT TERM...UPPER LOW OVER OVER NW ORE THIS EVNG MOVE SOUTH TO THE
BAY AREA BY LATE SAT...ALLOWING A LONGWAVE RIDGE AXIS NEAR 140W TO
EXPAND INTO THE PAC NW. SFC HIGH PRES HAS ALREADY SETTLED INTO THE
INTERIOR OF B.C...WITH THE KBLI-CYWL GRADIENT GETTING AS STRONG AS
-12 MB AS OF 03Z. AS A RESULT...A SHORT-LIVED FRASER OUTFLOW EVENT
IS UNDERWAY. THE AIR MASS COMING OUT OF B.C. IS NOT TERRIBLY COLD.
HOWEVER...THE AIR MASS IS DRY...WITH THE DEWPOINT AT KBLI NOW DOWN
TO 23F. DRIER AIR AND LARGE-SCALE SUBSIDENCE WILL SPREAD ACROSS THE
FCST AREA OVERNIGHT AND EARLY SAT MRNG...CAUSING THE FEW REMAINING
SPRINKLES TO DISSIPATE WITH SKIES CLEARING FROM NORTH TO SOUTH.

HIGH PRESSURE OVER B.C. WILL MOVE OUT EAST OF THE ROCKIES ON
SUNDAY...WITH PRESSURE GRADIENTS OVER WRN WA RELAXING ON SAT NGT.
WINDS WILL BECOME MUCH LIGHTER.

THE FLOW ALOFT WILL BACK TO NW ON SUNDAY AS A WEATHER SYSTEM
APPROACHES FROM THE NORTHWEST. THIS WEATHER SYSTEM WILL DROP DOWN
FROM THE NW SUN NIGHT AND MON...BRINGING CLOUDS. THE ECMWF AND NAM
SHOW RAIN ALL AREAS WITH THIS FEATURE BUT THE GFS JUST HAS SPOTTY
PRECIPITATION AND THE GEM IS DRY. THE FORECAST IS A BLEND OF THESE
MODELS FOR NOW WHICH MEANS MOSTLY CLOUDY WITH A CHANCE OF RAIN.
HANER

.LONG TERM...FROM PREVIOUS DISCUSSION...AN UPPER RIDGE WILL BE OVER
THE NORTHEAST PACIFIC TUESDAY AND WEDNESDAY...GIVING DRY NORTHERLY
FLOW ALOFT TO WESTERN WASHINGTON. THERE WILL BE SOME BREEZY NORTH
WINDS TUESDAY AS A SURFACE HIGH MOVES INTO SOUTHERN BRITISH
COLUMBIA...THEN LESS WIND WEDNESDAY AS THE HIGH SHIFTS SOUTHEAST.

MODELS SHOW THE UPPER RIDGE WEAKENING A BIT THURSDAY WITH A WARM
FRONT MOVING OVER THE TOP. THIS WILL BRING SOME CLOUDS TO THE AREA
AND PERHAPS A CHANCE OF RAIN...WITH THE BEST CHANCES COAST AND FAR
NORTH. A COLD FRONT WILL APPROACH FROM THE WEST ON FRIDAY. THIS DAY
COULD WIND UP BEING DRY BUT A CHANCE OF RAIN CANNOT BE COMPLETELY
RULED OUT FOR NOW. SCHNEIDER

&&

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

&&

.AVIATION...AN UPPER LEVEL LOW OVER OREGON WILL CONTINUE TRACKING
SOUTH TONIGHT. THE FLOW ALOFT OVER WESTERN WA IS NORTHERLY. LIGHT
SHOWERS ARE LIMITED TO THE SOUTHERN PORTION OF THE CWA THIS
EVENING...MAINLY SOUTH OF SEATAC AS THIS SYSTEM PULLS FARTHER SOUTH.
MEANWHILE MODERATE NORTH TO NE SURFACE WINDS WILL SCOUR OUT THE LOW
LEVEL CLOUDS WITH SKIES BECOMING CLEAR FROM NORTH TO SOUTH TONIGHT.
ALTHOUGH KCLM WILL SEE A CEILING WITH NE UPSLOPE WINDS. PATCHY
SHALLOW FOG WILL BE LIMITED TO KOLM OVERNIGHT. EXPECT VFR CONDITIONS
ON SAT WITH OFFSHORE FLOW. 33

KSEA...N WINDS WILL PREVAIL TONIGHT TO 10-15 KT. SKIES CLEARING BY
09Z WITH VFR CONDITIONS EXPECTED. 33

&&

.MARINE...NORTH TO NORTHEAST FLOW WILL CONTINUE ACROSS WESTERN WA
TONIGHT AS A 1008 MB SURFACE LOW TRACKS SOUTH ALONG THE SOUTHERN
OREGON COAST. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL WATERS.
HIGH PRESSURE OVER INTERIOR B.C. WILL MAINTAIN OFFSHORE ON SATURDAY.
A WEAK SURFACE TROUGH WILL CROSS THE WATERS ON SUN FOR BRIEF ONSHORE
WINDS. NORTH TO NE FLOW WILL DEVELOP MONDAY NIGHT THROUGH TUESDAY AS
ANOTHER SURFACE RIDGE BUILDS OVER B.C. 33

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS.

&&

$$

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







000
FXUS66 KSEW 272303
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PST FRI FEB 27 2015

.SYNOPSIS...SHOWERS WILL END TONIGHT AS DRIER NORTHERLY FLOW ALOFT
AND LOW LEVEL OFFSHORE FLOW DEVELOPS. THE UPPER RIDGE AND OFFSHORE
FLOW WILL BRING SUNNY DAYS AND COOL NIGHTS THIS WEEKEND. A WEAK
SYSTEM WILL MOVE THROUGH SUNDAY NIGHT AND MONDAY...WITH DRY WEATHER
AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...AN UPPER LOW OVER NORTHWEST OREGON WILL SHIFT SOUTH
TONIGHT. SHOWERS WILL CONTINUE TO DECREASE ACROSS THE AREA THIS
EVENING AS THE UPPER LOW PULLS AWAY. SHOWERS SHOULD PRETTY MUCH COME
TO AN END AFTER MIDNIGHT TONIGHT AS DRIER NORTHERLY FLOW ALOFT AND
LOW LEVEL OFFSHORE FLOW DEVELOP.

A SURFACE HIGH MOVING INTO SOUTHERN BRITISH COLUMBIA WILL RESULT IN
LOCALLY BREEZY NORTHERLY WINDS TONIGHT AND SATURDAY. OTHERWISE...
SATURDAY SHOULD BE A SUNNY DAY AFTER SOME LINGERING EARLY MORNING
CLOUDS. SUNDAY SHOULD BE ANOTHER SUNNY DAY.

LOW LEVEL OFFSHORE FLOW WILL WEAKEN AND THE FLOW ALOFT WILL BACK TO
NORTHWEST ON WEDNESDAY AS A WEATHER SYSTEM APPROACHES FROM THE
NORTHWEST FOR LESS WIND. THIS WEATHER SYSTEM WILL DROP DOWN FROM THE
NORTHWEST SUNDAY NIGHT AND MONDAY...BRINGING CLOUDS. THE ECMWF SHOWS
RAIN ALL AREAS WITH THIS FEATURE BUT THE GFS JUST HAS SPOTTY
PRECIPITATION AND THE GEM IS DRY. THE FORECAST IS A BLEND OF THESE
MODELS FOR NOW WHICH MEANS MOSTLY CLOUDY WITH A CHANCE OF RAIN.
SCHNEIDER

.LONG TERM...AN UPPER RIDGE WILL BE OVER THE NORTHEAST PACIFIC
TUESDAY AND WEDNESDAY...GIVING DRY NORTHERLY FLOW ALOFT TO WESTERN
WASHINGTON. THERE WILL BE SOME BREEZY NORTH WINDS TUESDAY AS A
SURFACE HIGH MOVES INTO SOUTHERN BRITISH COLUMBIA...THEN LESS WIND
WEDNESDAY AS THE HIGH SHIFTS SOUTHEAST.

MODELS SHOW THE UPPER RIDGE WEAKENING A BIT THURSDAY WITH A WARM
FRONT MOVING OVER THE TOP. THIS WILL BRING SOME CLOUDS TO THE AREA
AND PERHAPS A CHANCE OF RAIN...WITH THE BEST CHANCES COAST AND FAR
NORTH. A COLD FRONT WILL APPROACH FROM THE WEST ON FRIDAY. THIS DAY
COULD WIND UP BEING DRY BUT A CHANCE OF RAIN CANNOT BE COMPLETELY
RULED OUT FOR NOW. SCHNEIDER

&&

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

&&

.AVIATION...A SMALL UPPER LEVEL AND SURFACE LOW NEAR ASTORIA AT 22Z
WILL MOVE S OVER N CA BY 12Z. DRIER N-NE FLOW SURFACE AND ALOFT WILL
GRADUALLY PUSH S OVER W WA TONIGHT AS AN UPPER LEVEL RIDGE MOVES
OVER N B.C. AND A SURFACE RIDGE MOVES OVER S B.C.

RAIN IS BEGINNING TO DIMINISH OVER THE N INTERIOR THIS AFTERNOON
WHILE SHOWERS HAVE DEVELOPED OVER THE SW INTERIOR. THIS HAS ALLOWED
A MIX OF CLOUD LAYERS TO PERSIST OVER W WA. VFR CONDITIONS
PREDOMINATE OVER THE N INTERIOR BUT A MIX OF VFR AND IFR CIGS IS
STILL PRESENT OVER PUGET SOUND AND THE SW INTERIOR. LATEST MODELS
STILL INDICATE DECREASING MOISTURE FROM THE N ACROSS THE AREA
TONIGHT...BUT PROBABLY A LITTLE SLOWER THAN PREVIOUSLY EXPECTED. THE
SURFACE RIDGE OVER S B.C. WILL INCREASE N-NE SURFACE WINDS ACROSS W
WA THROUGH 06Z WITH LOCALLY WINDY CONDITIONS CONTINUING THROUGH
18Z...PARTICULARLY OVER THE N INTERIOR. WITH AN UPPER LEVEL RIDGE
OVER B.C. ON SATURDAY AND DRY N-NE FLOW ALOFT...GOOD VFR CONDITIONS
ARE EXPECTED.

KSEA...CIGS AT KSEA ARE EXPECTED TO REMAIN VFR...GENERALLY
BKN-OVC050 AND HIGHER THROUGH 09Z...WITH CLOUD LAYERS BECOMING
SCATTERED AFTER 09Z. N-NE SURFACE WINDS WILL REMAIN 5-10 KT THROUGH
09Z...INCREASING TO 10-15 AFTER 09Z. THE INCREASE IN SURFACE WINDS
WILL PROVIDE ENOUGH MIXING TO PRECLUDE FOG FROM FORMING. KAM

&&

.MARINE...A 1006 MB SURFACE LOW NEAR ASTORIA AT 22Z WILL MOVE S OVER
N CA BY 12Z SATURDAY. MODERATE N-NE SURFACE FLOW WILL DEVELOP THIS
EVENING AS A SURFACE RIDGE MOVES DOWN OVER SOUTHERN B.C. BEHIND THE
LOW. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL WATERS FOR THE
N-NE SURFACE WINDS. MOST AREAS SHOULD REMAIN IN THE 15-25
RANGE...BUT THE N INLAND WATERS AND THE E ENTRANCE SHOULD BE A
LITTLE STRONGER. THE CANADIAN MESOSCALE MODEL IS STILL THE ONLY ONE
THAT SHOWS 30-35 KT GALE WINDS OVER THE N INLAND AND E ENTRANCE FROM
06Z-12Z...SO I WILL STICK WITH THE CONSENSUS AND KEEP WINDS 30 KT OR
BELOW.

SURFACE WINDS WILL GRADUALLY DIMINISH SATURDAY AS THE SURFACE RIDGE
SETTLES OVER W WA.

MODELS SHOW AN UPPER LEVEL AND SURFACE TROUGH MOVING S ACROSS THE
AREA SUNDAY NIGHT. THE WRF-GFS INDICATED A BRIEF PERIOD OF NORTHERLY
SCA WINDS MAINLY OVER THE COASTAL WATERS AND THROUGH PUGET SOUND
IMMEDIATELY BEHIND THIS FEATURE. ANOTHER SURFACE RIDGE WILL MOVE
DOWN OVER B.C. MONDAY NIGHT AND TUESDAY FOR ANOTHER PERIOD OF
MODERATE E-NE FLOW. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS.

&&

$$

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













000
FXUS66 KSEW 272303
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PST FRI FEB 27 2015

.SYNOPSIS...SHOWERS WILL END TONIGHT AS DRIER NORTHERLY FLOW ALOFT
AND LOW LEVEL OFFSHORE FLOW DEVELOPS. THE UPPER RIDGE AND OFFSHORE
FLOW WILL BRING SUNNY DAYS AND COOL NIGHTS THIS WEEKEND. A WEAK
SYSTEM WILL MOVE THROUGH SUNDAY NIGHT AND MONDAY...WITH DRY WEATHER
AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...AN UPPER LOW OVER NORTHWEST OREGON WILL SHIFT SOUTH
TONIGHT. SHOWERS WILL CONTINUE TO DECREASE ACROSS THE AREA THIS
EVENING AS THE UPPER LOW PULLS AWAY. SHOWERS SHOULD PRETTY MUCH COME
TO AN END AFTER MIDNIGHT TONIGHT AS DRIER NORTHERLY FLOW ALOFT AND
LOW LEVEL OFFSHORE FLOW DEVELOP.

A SURFACE HIGH MOVING INTO SOUTHERN BRITISH COLUMBIA WILL RESULT IN
LOCALLY BREEZY NORTHERLY WINDS TONIGHT AND SATURDAY. OTHERWISE...
SATURDAY SHOULD BE A SUNNY DAY AFTER SOME LINGERING EARLY MORNING
CLOUDS. SUNDAY SHOULD BE ANOTHER SUNNY DAY.

LOW LEVEL OFFSHORE FLOW WILL WEAKEN AND THE FLOW ALOFT WILL BACK TO
NORTHWEST ON WEDNESDAY AS A WEATHER SYSTEM APPROACHES FROM THE
NORTHWEST FOR LESS WIND. THIS WEATHER SYSTEM WILL DROP DOWN FROM THE
NORTHWEST SUNDAY NIGHT AND MONDAY...BRINGING CLOUDS. THE ECMWF SHOWS
RAIN ALL AREAS WITH THIS FEATURE BUT THE GFS JUST HAS SPOTTY
PRECIPITATION AND THE GEM IS DRY. THE FORECAST IS A BLEND OF THESE
MODELS FOR NOW WHICH MEANS MOSTLY CLOUDY WITH A CHANCE OF RAIN.
SCHNEIDER

.LONG TERM...AN UPPER RIDGE WILL BE OVER THE NORTHEAST PACIFIC
TUESDAY AND WEDNESDAY...GIVING DRY NORTHERLY FLOW ALOFT TO WESTERN
WASHINGTON. THERE WILL BE SOME BREEZY NORTH WINDS TUESDAY AS A
SURFACE HIGH MOVES INTO SOUTHERN BRITISH COLUMBIA...THEN LESS WIND
WEDNESDAY AS THE HIGH SHIFTS SOUTHEAST.

MODELS SHOW THE UPPER RIDGE WEAKENING A BIT THURSDAY WITH A WARM
FRONT MOVING OVER THE TOP. THIS WILL BRING SOME CLOUDS TO THE AREA
AND PERHAPS A CHANCE OF RAIN...WITH THE BEST CHANCES COAST AND FAR
NORTH. A COLD FRONT WILL APPROACH FROM THE WEST ON FRIDAY. THIS DAY
COULD WIND UP BEING DRY BUT A CHANCE OF RAIN CANNOT BE COMPLETELY
RULED OUT FOR NOW. SCHNEIDER

&&

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

&&

.AVIATION...A SMALL UPPER LEVEL AND SURFACE LOW NEAR ASTORIA AT 22Z
WILL MOVE S OVER N CA BY 12Z. DRIER N-NE FLOW SURFACE AND ALOFT WILL
GRADUALLY PUSH S OVER W WA TONIGHT AS AN UPPER LEVEL RIDGE MOVES
OVER N B.C. AND A SURFACE RIDGE MOVES OVER S B.C.

RAIN IS BEGINNING TO DIMINISH OVER THE N INTERIOR THIS AFTERNOON
WHILE SHOWERS HAVE DEVELOPED OVER THE SW INTERIOR. THIS HAS ALLOWED
A MIX OF CLOUD LAYERS TO PERSIST OVER W WA. VFR CONDITIONS
PREDOMINATE OVER THE N INTERIOR BUT A MIX OF VFR AND IFR CIGS IS
STILL PRESENT OVER PUGET SOUND AND THE SW INTERIOR. LATEST MODELS
STILL INDICATE DECREASING MOISTURE FROM THE N ACROSS THE AREA
TONIGHT...BUT PROBABLY A LITTLE SLOWER THAN PREVIOUSLY EXPECTED. THE
SURFACE RIDGE OVER S B.C. WILL INCREASE N-NE SURFACE WINDS ACROSS W
WA THROUGH 06Z WITH LOCALLY WINDY CONDITIONS CONTINUING THROUGH
18Z...PARTICULARLY OVER THE N INTERIOR. WITH AN UPPER LEVEL RIDGE
OVER B.C. ON SATURDAY AND DRY N-NE FLOW ALOFT...GOOD VFR CONDITIONS
ARE EXPECTED.

KSEA...CIGS AT KSEA ARE EXPECTED TO REMAIN VFR...GENERALLY
BKN-OVC050 AND HIGHER THROUGH 09Z...WITH CLOUD LAYERS BECOMING
SCATTERED AFTER 09Z. N-NE SURFACE WINDS WILL REMAIN 5-10 KT THROUGH
09Z...INCREASING TO 10-15 AFTER 09Z. THE INCREASE IN SURFACE WINDS
WILL PROVIDE ENOUGH MIXING TO PRECLUDE FOG FROM FORMING. KAM

&&

.MARINE...A 1006 MB SURFACE LOW NEAR ASTORIA AT 22Z WILL MOVE S OVER
N CA BY 12Z SATURDAY. MODERATE N-NE SURFACE FLOW WILL DEVELOP THIS
EVENING AS A SURFACE RIDGE MOVES DOWN OVER SOUTHERN B.C. BEHIND THE
LOW. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL WATERS FOR THE
N-NE SURFACE WINDS. MOST AREAS SHOULD REMAIN IN THE 15-25
RANGE...BUT THE N INLAND WATERS AND THE E ENTRANCE SHOULD BE A
LITTLE STRONGER. THE CANADIAN MESOSCALE MODEL IS STILL THE ONLY ONE
THAT SHOWS 30-35 KT GALE WINDS OVER THE N INLAND AND E ENTRANCE FROM
06Z-12Z...SO I WILL STICK WITH THE CONSENSUS AND KEEP WINDS 30 KT OR
BELOW.

SURFACE WINDS WILL GRADUALLY DIMINISH SATURDAY AS THE SURFACE RIDGE
SETTLES OVER W WA.

MODELS SHOW AN UPPER LEVEL AND SURFACE TROUGH MOVING S ACROSS THE
AREA SUNDAY NIGHT. THE WRF-GFS INDICATED A BRIEF PERIOD OF NORTHERLY
SCA WINDS MAINLY OVER THE COASTAL WATERS AND THROUGH PUGET SOUND
IMMEDIATELY BEHIND THIS FEATURE. ANOTHER SURFACE RIDGE WILL MOVE
DOWN OVER B.C. MONDAY NIGHT AND TUESDAY FOR ANOTHER PERIOD OF
MODERATE E-NE FLOW. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS.

&&

$$

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














000
FXUS66 KSEW 272303
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PST FRI FEB 27 2015

.SYNOPSIS...SHOWERS WILL END TONIGHT AS DRIER NORTHERLY FLOW ALOFT
AND LOW LEVEL OFFSHORE FLOW DEVELOPS. THE UPPER RIDGE AND OFFSHORE
FLOW WILL BRING SUNNY DAYS AND COOL NIGHTS THIS WEEKEND. A WEAK
SYSTEM WILL MOVE THROUGH SUNDAY NIGHT AND MONDAY...WITH DRY WEATHER
AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...AN UPPER LOW OVER NORTHWEST OREGON WILL SHIFT SOUTH
TONIGHT. SHOWERS WILL CONTINUE TO DECREASE ACROSS THE AREA THIS
EVENING AS THE UPPER LOW PULLS AWAY. SHOWERS SHOULD PRETTY MUCH COME
TO AN END AFTER MIDNIGHT TONIGHT AS DRIER NORTHERLY FLOW ALOFT AND
LOW LEVEL OFFSHORE FLOW DEVELOP.

A SURFACE HIGH MOVING INTO SOUTHERN BRITISH COLUMBIA WILL RESULT IN
LOCALLY BREEZY NORTHERLY WINDS TONIGHT AND SATURDAY. OTHERWISE...
SATURDAY SHOULD BE A SUNNY DAY AFTER SOME LINGERING EARLY MORNING
CLOUDS. SUNDAY SHOULD BE ANOTHER SUNNY DAY.

LOW LEVEL OFFSHORE FLOW WILL WEAKEN AND THE FLOW ALOFT WILL BACK TO
NORTHWEST ON WEDNESDAY AS A WEATHER SYSTEM APPROACHES FROM THE
NORTHWEST FOR LESS WIND. THIS WEATHER SYSTEM WILL DROP DOWN FROM THE
NORTHWEST SUNDAY NIGHT AND MONDAY...BRINGING CLOUDS. THE ECMWF SHOWS
RAIN ALL AREAS WITH THIS FEATURE BUT THE GFS JUST HAS SPOTTY
PRECIPITATION AND THE GEM IS DRY. THE FORECAST IS A BLEND OF THESE
MODELS FOR NOW WHICH MEANS MOSTLY CLOUDY WITH A CHANCE OF RAIN.
SCHNEIDER

.LONG TERM...AN UPPER RIDGE WILL BE OVER THE NORTHEAST PACIFIC
TUESDAY AND WEDNESDAY...GIVING DRY NORTHERLY FLOW ALOFT TO WESTERN
WASHINGTON. THERE WILL BE SOME BREEZY NORTH WINDS TUESDAY AS A
SURFACE HIGH MOVES INTO SOUTHERN BRITISH COLUMBIA...THEN LESS WIND
WEDNESDAY AS THE HIGH SHIFTS SOUTHEAST.

MODELS SHOW THE UPPER RIDGE WEAKENING A BIT THURSDAY WITH A WARM
FRONT MOVING OVER THE TOP. THIS WILL BRING SOME CLOUDS TO THE AREA
AND PERHAPS A CHANCE OF RAIN...WITH THE BEST CHANCES COAST AND FAR
NORTH. A COLD FRONT WILL APPROACH FROM THE WEST ON FRIDAY. THIS DAY
COULD WIND UP BEING DRY BUT A CHANCE OF RAIN CANNOT BE COMPLETELY
RULED OUT FOR NOW. SCHNEIDER

&&

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

&&

.AVIATION...A SMALL UPPER LEVEL AND SURFACE LOW NEAR ASTORIA AT 22Z
WILL MOVE S OVER N CA BY 12Z. DRIER N-NE FLOW SURFACE AND ALOFT WILL
GRADUALLY PUSH S OVER W WA TONIGHT AS AN UPPER LEVEL RIDGE MOVES
OVER N B.C. AND A SURFACE RIDGE MOVES OVER S B.C.

RAIN IS BEGINNING TO DIMINISH OVER THE N INTERIOR THIS AFTERNOON
WHILE SHOWERS HAVE DEVELOPED OVER THE SW INTERIOR. THIS HAS ALLOWED
A MIX OF CLOUD LAYERS TO PERSIST OVER W WA. VFR CONDITIONS
PREDOMINATE OVER THE N INTERIOR BUT A MIX OF VFR AND IFR CIGS IS
STILL PRESENT OVER PUGET SOUND AND THE SW INTERIOR. LATEST MODELS
STILL INDICATE DECREASING MOISTURE FROM THE N ACROSS THE AREA
TONIGHT...BUT PROBABLY A LITTLE SLOWER THAN PREVIOUSLY EXPECTED. THE
SURFACE RIDGE OVER S B.C. WILL INCREASE N-NE SURFACE WINDS ACROSS W
WA THROUGH 06Z WITH LOCALLY WINDY CONDITIONS CONTINUING THROUGH
18Z...PARTICULARLY OVER THE N INTERIOR. WITH AN UPPER LEVEL RIDGE
OVER B.C. ON SATURDAY AND DRY N-NE FLOW ALOFT...GOOD VFR CONDITIONS
ARE EXPECTED.

KSEA...CIGS AT KSEA ARE EXPECTED TO REMAIN VFR...GENERALLY
BKN-OVC050 AND HIGHER THROUGH 09Z...WITH CLOUD LAYERS BECOMING
SCATTERED AFTER 09Z. N-NE SURFACE WINDS WILL REMAIN 5-10 KT THROUGH
09Z...INCREASING TO 10-15 AFTER 09Z. THE INCREASE IN SURFACE WINDS
WILL PROVIDE ENOUGH MIXING TO PRECLUDE FOG FROM FORMING. KAM

&&

.MARINE...A 1006 MB SURFACE LOW NEAR ASTORIA AT 22Z WILL MOVE S OVER
N CA BY 12Z SATURDAY. MODERATE N-NE SURFACE FLOW WILL DEVELOP THIS
EVENING AS A SURFACE RIDGE MOVES DOWN OVER SOUTHERN B.C. BEHIND THE
LOW. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL WATERS FOR THE
N-NE SURFACE WINDS. MOST AREAS SHOULD REMAIN IN THE 15-25
RANGE...BUT THE N INLAND WATERS AND THE E ENTRANCE SHOULD BE A
LITTLE STRONGER. THE CANADIAN MESOSCALE MODEL IS STILL THE ONLY ONE
THAT SHOWS 30-35 KT GALE WINDS OVER THE N INLAND AND E ENTRANCE FROM
06Z-12Z...SO I WILL STICK WITH THE CONSENSUS AND KEEP WINDS 30 KT OR
BELOW.

SURFACE WINDS WILL GRADUALLY DIMINISH SATURDAY AS THE SURFACE RIDGE
SETTLES OVER W WA.

MODELS SHOW AN UPPER LEVEL AND SURFACE TROUGH MOVING S ACROSS THE
AREA SUNDAY NIGHT. THE WRF-GFS INDICATED A BRIEF PERIOD OF NORTHERLY
SCA WINDS MAINLY OVER THE COASTAL WATERS AND THROUGH PUGET SOUND
IMMEDIATELY BEHIND THIS FEATURE. ANOTHER SURFACE RIDGE WILL MOVE
DOWN OVER B.C. MONDAY NIGHT AND TUESDAY FOR ANOTHER PERIOD OF
MODERATE E-NE FLOW. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS.

&&

$$

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













000
FXUS66 KSEW 271709
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
910 AM PST FRI FEB 27 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL PRODUCE WIDESPREAD SHOWERS
ACROSS WESTERN WASHINGTON TODAY AS IT MOVES SOUTHEAST FROM THE COAST
TOWARD OREGON. A FEW INCHES OF SNOW WILL FALL IN THE MOUNTAINS. AN
UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS AND COOL NIGHTS
THIS WEEKEND. A WEAK SYSTEM WILL MOVE THROUGH SUNDAY NIGHT AND
MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...AN UPPER LOW OVER SOUTHWEST WASHINGTON WILL SHIFT
SOUTH OF THE STATE LATER TODAY. SHOWERS OVER THE AREA THIS MORNING
WILL BEGIN TO DECREASE FROM NORTH TO SOUTH THIS AFTERNOON AS THE
UPPER LOW PULLS AWAY. SHOWERS SHOULD PRETTY MUCH COME TO AN END
AFTER MIDNIGHT TONIGHT AS DRIER NORTHERLY FLOW ALOFT DEVELOPS ALONG
WITH LOW LEVEL OFFSHORE FLOW. A SURFACE HIGH MOVING INTO SOUTHERN
BRITISH COLUMBIA WILL RESULT IN LOCALLY BREEZY NORTHERLY WINDS
TONIGHT AND SATURDAY. OTHERWISE...SATURDAY SHOULD BE A SUNNY DAY
AFTER SOME LINGERING EARLY MORNING CLOUDS BURN OFF WITH OFFSHORE
FLOW IN CONTROL. SUNDAY SHOULD BE ANOTHER SUNNY DAY. LOW LEVEL
OFFSHORE FLOW WILL WEAKEN AND FLOW ALOFT WILL BACK TO NORTHWEST AS A
WEATHER SYSTEM APPROACHES FROM THE NORTHWEST FOR LESS WIND.

FOR TODAY...THE MOUNTAINS WILL GET SOME SNOW FOR THE FIRST TIME IN
QUITE AWHILE. SNOW APPEARS TO BE ACCUMULATING ABOVE ABOUT 3500 FEET.
PARADISE ON MOUNT RAINIER HAS PICKED UP 5 INCHES SO FAR AND WILL
PROBABLY REACH LOW END ADVISORY TOTALS BY LATE THIS MORNING BUT
OTHER AREAS LOOK LIKE THEY WILL STAY BELOW ADVISORY CRITERIA.
SCHNEIDER

.LONG TERM...PREVIOUS DISCUSSION...AN UPPER SHORTWAVE THAT MOVES
INTO WESTERN WASHINGTON SUNDAY NIGHT WILL MAINTAIN A CHANCE OF
SHOWERS MONDAY AND MONDAY NIGHT...BUT AGAIN AMOUNTS LOOK LIGHT AND
COVERAGE SHOULD BE SPOTTY. DRY NORTHERLY FLOW WILL TAKE OVER AGAIN
TUESDAY AHEAD OF A STRONG UPPER RIDGE OFFSHORE OUTSIDE OF 130W. THE
UPPER RIDGE WILL MOVE SLOWLY TOWARD THE REGION FOR ANOTHER DRY DAY
WEDNESDAY. IT WILL WEAKEN AS IT MOVES INLAND THURSDAY...AND A WEAK
SYSTEM MOVING OVER THE NORTH SIDE OF THE RIDGE COULD BRING SOME
PRECIPITATION TO WESTERN WASHINGTON. THE MODELS ALL AGREE ON THIS
GENERAL SCENARIO.   MCDONNAL

&&

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

&&

.AVIATION...A SMALL UPPER LEVEL AND SURFACE LOW OVER THE WA COAST AT
16Z WILL MOVE S OVER THE CENTRAL OREGON COAST AROUND 00Z. THE LOW
WILL CONTINUE S OVER N CA BY 12Z SATURDAY...ALLOWING COOLER AND DRY
NE FLOW ALOFT TO SPREAD OVER W WA.

CONDITIONS ACROSS W WA THIS MORNING ARE PREDOMINANTLY MVFR...WITH A
LITTLE IFR MIXED IN OVER S PUGET SOUND AND THE SW INTERIOR...AND
SOME HIGHER OVC030-050 CIGS OVER THE N PUGET SOUND AND THE N
INTERIOR WHERE THE STEADY RAIN IS STILL FALLING. 12Z NAM TIME-HEIGHT
SECTIONS STILL INDICATE CIGS LIFTING FROM THE N THIS AFTERNOON AS
THE LOW CONTINUES S. THIS SEEMS REASONABLE GIVEN THE GOOD VFR
CONDITIONS AT CYVR AND CYYJ...BUT THE PUGET SOUND REGION WILL
PROBABLY STILL HAVE SOME MVFR CIGS ALL THE WAY THROUGH 23Z. UPSLOPE
CONDITIONS CAUSED BY THE OLYMPICS NEAR KCLM SHOULD DELAY IMPROVEMENT
THERE EVEN FURTHER.

KSEA...CIGS AT KSEA ARE EXPECTED TO REMAIN IN THE
MVFR...OVC020-030...OR LOW END VFR RANGE...OVC030-040 THROUGH AROUND
20Z...PER THE LATEST HIGH RESOLUTION HRRR MODEL. SOME PERIODS OF
CIGS BELOW BKN020 ARE NOT OUT OF THE QUESTION. THESE LOWER CIGS
COULD REMAIN IN THE VICINITY OF KSEA THROUGH 23Z. SURFACE WINDS WILL
REMAIN NE 5-8 KT. KAM

&&

.MARINE...A 1005 MB SURFACE LOW OVER THE S WA COAST WILL SLIDE S
OVER THE CENTRAL OREGON COAST THIS AFTERNOON. A 1032 MB SURFACE
RIDGE OVER CENTRAL B.C. WILL MOVE S BEHIND THE SURFACE LOW. THIS
WILL ALLOW N-NE FLOW TO STRENGTHEN OVER W WA TODAY...WITH MODERATE
FLOW CONTINUING THROUGH SATURDAY MORNING. THE SURFACE RIDGE WILL
SETTLE OVER W WA SATURDAY AFTERNOON...ALLOWING NORTHERLY PRESSURE
GRADIENTS TO WEAKEN. SMALL CRAFT ADVISORIES HAVE BEEN ISSUED FOR ALL
THE WA WATERS...BUT SOME TAKE EFFECT LATER TODAY. THERE IS SOME
CONCERN THAT THE NE FLOW OVER THE N INLAND WATERS WILL REACH
BORDERLINE GALE LEVELS...HOWEVER AT THIS POINT THE ONLY MODEL
INDICATING SUCH IS THE 06Z CANADIAN LAM...AND THE 30-35 KT WINDS ARE
RATHER SPOTTY.

THE SURFACE RIDGE WILL LAST OVER W WA SATURDAY AFTERNOON THROUGH
SUNDAY AFTERNOON. A WEAK SHORTWAVE TROUGH WILL MOVE S ALONG THE B.C.
COAST SUNDAY NIGHT...BUT SURFACE REFLECTION WILL BE WEAK. A WEAKER
EPISODE OF N-NE FLOW IS EXPECTED BEHIND THE TROUGH ON MONDAY. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS.

&&

$$

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










000
FXUS66 KSEW 271709
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
910 AM PST FRI FEB 27 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL PRODUCE WIDESPREAD SHOWERS
ACROSS WESTERN WASHINGTON TODAY AS IT MOVES SOUTHEAST FROM THE COAST
TOWARD OREGON. A FEW INCHES OF SNOW WILL FALL IN THE MOUNTAINS. AN
UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS AND COOL NIGHTS
THIS WEEKEND. A WEAK SYSTEM WILL MOVE THROUGH SUNDAY NIGHT AND
MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...AN UPPER LOW OVER SOUTHWEST WASHINGTON WILL SHIFT
SOUTH OF THE STATE LATER TODAY. SHOWERS OVER THE AREA THIS MORNING
WILL BEGIN TO DECREASE FROM NORTH TO SOUTH THIS AFTERNOON AS THE
UPPER LOW PULLS AWAY. SHOWERS SHOULD PRETTY MUCH COME TO AN END
AFTER MIDNIGHT TONIGHT AS DRIER NORTHERLY FLOW ALOFT DEVELOPS ALONG
WITH LOW LEVEL OFFSHORE FLOW. A SURFACE HIGH MOVING INTO SOUTHERN
BRITISH COLUMBIA WILL RESULT IN LOCALLY BREEZY NORTHERLY WINDS
TONIGHT AND SATURDAY. OTHERWISE...SATURDAY SHOULD BE A SUNNY DAY
AFTER SOME LINGERING EARLY MORNING CLOUDS BURN OFF WITH OFFSHORE
FLOW IN CONTROL. SUNDAY SHOULD BE ANOTHER SUNNY DAY. LOW LEVEL
OFFSHORE FLOW WILL WEAKEN AND FLOW ALOFT WILL BACK TO NORTHWEST AS A
WEATHER SYSTEM APPROACHES FROM THE NORTHWEST FOR LESS WIND.

FOR TODAY...THE MOUNTAINS WILL GET SOME SNOW FOR THE FIRST TIME IN
QUITE AWHILE. SNOW APPEARS TO BE ACCUMULATING ABOVE ABOUT 3500 FEET.
PARADISE ON MOUNT RAINIER HAS PICKED UP 5 INCHES SO FAR AND WILL
PROBABLY REACH LOW END ADVISORY TOTALS BY LATE THIS MORNING BUT
OTHER AREAS LOOK LIKE THEY WILL STAY BELOW ADVISORY CRITERIA.
SCHNEIDER

.LONG TERM...PREVIOUS DISCUSSION...AN UPPER SHORTWAVE THAT MOVES
INTO WESTERN WASHINGTON SUNDAY NIGHT WILL MAINTAIN A CHANCE OF
SHOWERS MONDAY AND MONDAY NIGHT...BUT AGAIN AMOUNTS LOOK LIGHT AND
COVERAGE SHOULD BE SPOTTY. DRY NORTHERLY FLOW WILL TAKE OVER AGAIN
TUESDAY AHEAD OF A STRONG UPPER RIDGE OFFSHORE OUTSIDE OF 130W. THE
UPPER RIDGE WILL MOVE SLOWLY TOWARD THE REGION FOR ANOTHER DRY DAY
WEDNESDAY. IT WILL WEAKEN AS IT MOVES INLAND THURSDAY...AND A WEAK
SYSTEM MOVING OVER THE NORTH SIDE OF THE RIDGE COULD BRING SOME
PRECIPITATION TO WESTERN WASHINGTON. THE MODELS ALL AGREE ON THIS
GENERAL SCENARIO.   MCDONNAL

&&

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

&&

.AVIATION...A SMALL UPPER LEVEL AND SURFACE LOW OVER THE WA COAST AT
16Z WILL MOVE S OVER THE CENTRAL OREGON COAST AROUND 00Z. THE LOW
WILL CONTINUE S OVER N CA BY 12Z SATURDAY...ALLOWING COOLER AND DRY
NE FLOW ALOFT TO SPREAD OVER W WA.

CONDITIONS ACROSS W WA THIS MORNING ARE PREDOMINANTLY MVFR...WITH A
LITTLE IFR MIXED IN OVER S PUGET SOUND AND THE SW INTERIOR...AND
SOME HIGHER OVC030-050 CIGS OVER THE N PUGET SOUND AND THE N
INTERIOR WHERE THE STEADY RAIN IS STILL FALLING. 12Z NAM TIME-HEIGHT
SECTIONS STILL INDICATE CIGS LIFTING FROM THE N THIS AFTERNOON AS
THE LOW CONTINUES S. THIS SEEMS REASONABLE GIVEN THE GOOD VFR
CONDITIONS AT CYVR AND CYYJ...BUT THE PUGET SOUND REGION WILL
PROBABLY STILL HAVE SOME MVFR CIGS ALL THE WAY THROUGH 23Z. UPSLOPE
CONDITIONS CAUSED BY THE OLYMPICS NEAR KCLM SHOULD DELAY IMPROVEMENT
THERE EVEN FURTHER.

KSEA...CIGS AT KSEA ARE EXPECTED TO REMAIN IN THE
MVFR...OVC020-030...OR LOW END VFR RANGE...OVC030-040 THROUGH AROUND
20Z...PER THE LATEST HIGH RESOLUTION HRRR MODEL. SOME PERIODS OF
CIGS BELOW BKN020 ARE NOT OUT OF THE QUESTION. THESE LOWER CIGS
COULD REMAIN IN THE VICINITY OF KSEA THROUGH 23Z. SURFACE WINDS WILL
REMAIN NE 5-8 KT. KAM

&&

.MARINE...A 1005 MB SURFACE LOW OVER THE S WA COAST WILL SLIDE S
OVER THE CENTRAL OREGON COAST THIS AFTERNOON. A 1032 MB SURFACE
RIDGE OVER CENTRAL B.C. WILL MOVE S BEHIND THE SURFACE LOW. THIS
WILL ALLOW N-NE FLOW TO STRENGTHEN OVER W WA TODAY...WITH MODERATE
FLOW CONTINUING THROUGH SATURDAY MORNING. THE SURFACE RIDGE WILL
SETTLE OVER W WA SATURDAY AFTERNOON...ALLOWING NORTHERLY PRESSURE
GRADIENTS TO WEAKEN. SMALL CRAFT ADVISORIES HAVE BEEN ISSUED FOR ALL
THE WA WATERS...BUT SOME TAKE EFFECT LATER TODAY. THERE IS SOME
CONCERN THAT THE NE FLOW OVER THE N INLAND WATERS WILL REACH
BORDERLINE GALE LEVELS...HOWEVER AT THIS POINT THE ONLY MODEL
INDICATING SUCH IS THE 06Z CANADIAN LAM...AND THE 30-35 KT WINDS ARE
RATHER SPOTTY.

THE SURFACE RIDGE WILL LAST OVER W WA SATURDAY AFTERNOON THROUGH
SUNDAY AFTERNOON. A WEAK SHORTWAVE TROUGH WILL MOVE S ALONG THE B.C.
COAST SUNDAY NIGHT...BUT SURFACE REFLECTION WILL BE WEAK. A WEAKER
EPISODE OF N-NE FLOW IS EXPECTED BEHIND THE TROUGH ON MONDAY. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS.

&&

$$

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










000
FXUS66 KSEW 271709
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
910 AM PST FRI FEB 27 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL PRODUCE WIDESPREAD SHOWERS
ACROSS WESTERN WASHINGTON TODAY AS IT MOVES SOUTHEAST FROM THE COAST
TOWARD OREGON. A FEW INCHES OF SNOW WILL FALL IN THE MOUNTAINS. AN
UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS AND COOL NIGHTS
THIS WEEKEND. A WEAK SYSTEM WILL MOVE THROUGH SUNDAY NIGHT AND
MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...AN UPPER LOW OVER SOUTHWEST WASHINGTON WILL SHIFT
SOUTH OF THE STATE LATER TODAY. SHOWERS OVER THE AREA THIS MORNING
WILL BEGIN TO DECREASE FROM NORTH TO SOUTH THIS AFTERNOON AS THE
UPPER LOW PULLS AWAY. SHOWERS SHOULD PRETTY MUCH COME TO AN END
AFTER MIDNIGHT TONIGHT AS DRIER NORTHERLY FLOW ALOFT DEVELOPS ALONG
WITH LOW LEVEL OFFSHORE FLOW. A SURFACE HIGH MOVING INTO SOUTHERN
BRITISH COLUMBIA WILL RESULT IN LOCALLY BREEZY NORTHERLY WINDS
TONIGHT AND SATURDAY. OTHERWISE...SATURDAY SHOULD BE A SUNNY DAY
AFTER SOME LINGERING EARLY MORNING CLOUDS BURN OFF WITH OFFSHORE
FLOW IN CONTROL. SUNDAY SHOULD BE ANOTHER SUNNY DAY. LOW LEVEL
OFFSHORE FLOW WILL WEAKEN AND FLOW ALOFT WILL BACK TO NORTHWEST AS A
WEATHER SYSTEM APPROACHES FROM THE NORTHWEST FOR LESS WIND.

FOR TODAY...THE MOUNTAINS WILL GET SOME SNOW FOR THE FIRST TIME IN
QUITE AWHILE. SNOW APPEARS TO BE ACCUMULATING ABOVE ABOUT 3500 FEET.
PARADISE ON MOUNT RAINIER HAS PICKED UP 5 INCHES SO FAR AND WILL
PROBABLY REACH LOW END ADVISORY TOTALS BY LATE THIS MORNING BUT
OTHER AREAS LOOK LIKE THEY WILL STAY BELOW ADVISORY CRITERIA.
SCHNEIDER

.LONG TERM...PREVIOUS DISCUSSION...AN UPPER SHORTWAVE THAT MOVES
INTO WESTERN WASHINGTON SUNDAY NIGHT WILL MAINTAIN A CHANCE OF
SHOWERS MONDAY AND MONDAY NIGHT...BUT AGAIN AMOUNTS LOOK LIGHT AND
COVERAGE SHOULD BE SPOTTY. DRY NORTHERLY FLOW WILL TAKE OVER AGAIN
TUESDAY AHEAD OF A STRONG UPPER RIDGE OFFSHORE OUTSIDE OF 130W. THE
UPPER RIDGE WILL MOVE SLOWLY TOWARD THE REGION FOR ANOTHER DRY DAY
WEDNESDAY. IT WILL WEAKEN AS IT MOVES INLAND THURSDAY...AND A WEAK
SYSTEM MOVING OVER THE NORTH SIDE OF THE RIDGE COULD BRING SOME
PRECIPITATION TO WESTERN WASHINGTON. THE MODELS ALL AGREE ON THIS
GENERAL SCENARIO.   MCDONNAL

&&

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

&&

.AVIATION...A SMALL UPPER LEVEL AND SURFACE LOW OVER THE WA COAST AT
16Z WILL MOVE S OVER THE CENTRAL OREGON COAST AROUND 00Z. THE LOW
WILL CONTINUE S OVER N CA BY 12Z SATURDAY...ALLOWING COOLER AND DRY
NE FLOW ALOFT TO SPREAD OVER W WA.

CONDITIONS ACROSS W WA THIS MORNING ARE PREDOMINANTLY MVFR...WITH A
LITTLE IFR MIXED IN OVER S PUGET SOUND AND THE SW INTERIOR...AND
SOME HIGHER OVC030-050 CIGS OVER THE N PUGET SOUND AND THE N
INTERIOR WHERE THE STEADY RAIN IS STILL FALLING. 12Z NAM TIME-HEIGHT
SECTIONS STILL INDICATE CIGS LIFTING FROM THE N THIS AFTERNOON AS
THE LOW CONTINUES S. THIS SEEMS REASONABLE GIVEN THE GOOD VFR
CONDITIONS AT CYVR AND CYYJ...BUT THE PUGET SOUND REGION WILL
PROBABLY STILL HAVE SOME MVFR CIGS ALL THE WAY THROUGH 23Z. UPSLOPE
CONDITIONS CAUSED BY THE OLYMPICS NEAR KCLM SHOULD DELAY IMPROVEMENT
THERE EVEN FURTHER.

KSEA...CIGS AT KSEA ARE EXPECTED TO REMAIN IN THE
MVFR...OVC020-030...OR LOW END VFR RANGE...OVC030-040 THROUGH AROUND
20Z...PER THE LATEST HIGH RESOLUTION HRRR MODEL. SOME PERIODS OF
CIGS BELOW BKN020 ARE NOT OUT OF THE QUESTION. THESE LOWER CIGS
COULD REMAIN IN THE VICINITY OF KSEA THROUGH 23Z. SURFACE WINDS WILL
REMAIN NE 5-8 KT. KAM

&&

.MARINE...A 1005 MB SURFACE LOW OVER THE S WA COAST WILL SLIDE S
OVER THE CENTRAL OREGON COAST THIS AFTERNOON. A 1032 MB SURFACE
RIDGE OVER CENTRAL B.C. WILL MOVE S BEHIND THE SURFACE LOW. THIS
WILL ALLOW N-NE FLOW TO STRENGTHEN OVER W WA TODAY...WITH MODERATE
FLOW CONTINUING THROUGH SATURDAY MORNING. THE SURFACE RIDGE WILL
SETTLE OVER W WA SATURDAY AFTERNOON...ALLOWING NORTHERLY PRESSURE
GRADIENTS TO WEAKEN. SMALL CRAFT ADVISORIES HAVE BEEN ISSUED FOR ALL
THE WA WATERS...BUT SOME TAKE EFFECT LATER TODAY. THERE IS SOME
CONCERN THAT THE NE FLOW OVER THE N INLAND WATERS WILL REACH
BORDERLINE GALE LEVELS...HOWEVER AT THIS POINT THE ONLY MODEL
INDICATING SUCH IS THE 06Z CANADIAN LAM...AND THE 30-35 KT WINDS ARE
RATHER SPOTTY.

THE SURFACE RIDGE WILL LAST OVER W WA SATURDAY AFTERNOON THROUGH
SUNDAY AFTERNOON. A WEAK SHORTWAVE TROUGH WILL MOVE S ALONG THE B.C.
COAST SUNDAY NIGHT...BUT SURFACE REFLECTION WILL BE WEAK. A WEAKER
EPISODE OF N-NE FLOW IS EXPECTED BEHIND THE TROUGH ON MONDAY. KAM

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS.

&&

$$

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











000
FXUS66 KSEW 271059
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 AM PST FRI FEB 27 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL PRODUCE WIDESPREAD SHOWERS
ACROSS WESTERN WASHINGTON TODAY AS IT MOVES SOUTHEAST FROM THE COAST
TOWARD OREGON. A FEW INCHES OF SNOW WILL FALL IN THE MOUNTAINS. AN
UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS AND COOL NIGHTS
THIS WEEKEND. A WEAK SYSTEM WILL MOVE THROUGH SUNDAY NIGHT AND
MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...A SMALL UPPER LOW THAT WAS NEAR THE NORTH TIP OF
VANCOUVER ISLAND MOVED SOUTHEAST INTO THE WASHINGTON COASTAL WATERS
OVERNIGHT. THIS FEATURE PRODUCED WIDESPREAD LIGHT TO MODERATE
SHOWERS ACROSS WESTERN WASHINGTON OVERNIGHT...WITH MORE THAN 0.25
INCH OF PRECIPITATION IN MANY PLACES. AT 2 AM THE SHOWERS WERE
MAINLY IN A BAND OVER THE INTERIOR LOWLANDS WITH TEMPERATURES IN THE
MID 40S TO LOWER 50S.

THE UPPER LOW WILL CONTINUE ITS SOUTHEAST TRACK...MOVING INTO
NORTHWEST OREGON TODAY AND SOUTHEAST OREGON OR NORTHWEST NEVADA
TONIGHT. THE UPPER FLOW OVER WESTERN WASHINGTON WILL VEER TO NORTH
AND THEN NORTHEAST...AND NORTHERLY OFFSHORE LOW LEVEL FLOW WILL
DEVELOP TOO AS SURFACE HIGH PRESSURE MOVES SOUTH ACROSS BRITISH
COLUMBIA.

SHOWERS SHOULD REMAIN FAIRLY WIDESPREAD TODAY...ESPECIALLY THIS
MORNING...BUT THEY WILL DECREASE FROM NORTH TO SOUTH LATE TODAY AND
TONIGHT AS THE DRY AND COOLER NORTHERLY FLOW TAKES OVER. BY LATE
TONIGHT SKIES WILL BE CLEARING...WITH LIGHT SPOTTY SHOWERS LIMITED
TO THE SOUTH PART OF THE FORECAST AREA AND PERHAPS A WEAK
CONVERGENCE ZONE. BREEZY NORTH OR NORTHEAST WINDS WILL DEVELOP
TONIGHT...WITH THE STRONGEST WINDS IN THE NORTH INTERIOR NEAR THE
FRASER RIVER OUTFLOW SOURCE.

THE SNOW LEVEL WILL BE 3000 TO 3500 FT TODAY...THEN FALL SLIGHTLY
TONIGHT AS PRECIPITATION DECREASES. ANOTHER 2 TO 5 INCHES OF SNOW IS
LIKELY IN THE MOUNTAINS WITH THIS SYSTEM...WITH THE HEAVIEST AMOUNTS
IN THE OLYMPICS AND THE CASCADES SOUTH OF SNOQUALMIE PASS.

DRY NORTHERLY FLOW ALOFT WILL PREVAIL SATURDAY FOR A SUNNY DAY.
TEMPERATURES SHOULD CLIMB INTO THE LOWER 50S IN THE LOWLANDS...BUT
NORTHERLY OFFSHORE SURFACE FLOW WILL MAKE FOR BREEZY CONDITIONS
ACROSS MUCH OF THE FORECAST AREA. WINDS SHOULD EASE SATURDAY
NIGHT...WITH OVERNIGHT LOWS IN THE 30S AND LOCALLY BELOW FREEZING
UNDER MOSTLY CLEAR SKIES.

SUNDAY WILL BE ANOTHER DRY AND MOSTLY SUNNY DAY...BUT THE UPPER FLOW
WILL BACK TO NORTHWEST AS A WEAK UPPER SHORTWAVE STARTS APPROACHING
ALONG THE COAST OF BRITISH COLUMBIA. THE SHORTWAVE WILL MOVE ACROSS
WESTERN WASHINGTON SUNDAY NIGHT. IT WILL BRING A CHANCE OF
PRECIPITATION...BUT THE LATEST MODEL RUNS SUGGEST THAT AMOUNTS WILL
BE FAIRLY LIGHT AND COVERAGE MIGHT BE SPOTTY.   MCDONNAL

.LONG TERM...THE UPPER SHORTWAVE THAT MOVES INTO WESTERN WASHINGTON
SUNDAY NIGHT WILL MAINTAIN A CHANCE OF SHOWERS MONDAY AND MONDAY
NIGHT...BUT AGAIN AMOUNTS LOOK LIGHT AND COVERAGE SHOULD BE SPOTTY.
DRY NORTHERLY FLOW WILL TAKE OVER AGAIN TUESDAY AHEAD OF A STRONG
UPPER RIDGE OFFSHORE OUTSIDE OF 130W. THE UPPER RIDGE WILL MOVE
SLOWLY TOWARD THE REGION FOR ANOTHER DRY DAY WEDNESDAY. IT WILL
WEAKEN AS IT MOVES INLAND THURSDAY...AND A WEAK SYSTEM MOVING OVER
THE NORTH SIDE OF THE RIDGE COULD BRING SOME PRECIPITATION TO
WESTERN WASHINGTON. THE MODELS ALL AGREE ON THIS GENERAL SCENARIO.
MCDONNAL

&&

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

&&

.AVIATION...A SURFACE AND UPPER LEVEL LOW IS DROPPING SOUTHWARD
ALONG THE WASHINGTON COAST EARLY THIS MORNING. THE LOW WILL DROPS
SOUTH THROUGH THE COASTAL WATERS OF OREGON TODAY. THE AIR MASS IS
MOIST AND STABLE ACROSS WESTERN WASHINGTON. NORTHEASTERLY FLOW OVER
THE FAR NORTHERN PORTIONS OF THE INTERIOR ARE GIVING VFR CONDITIONS
THERE. ELSEWHERE...RAIN AND LOW LEVEL CONVERGENCE IS GIVING MVFR
CEILINGS AND LOCAL IFR CONDITIONS. CONDITIONS WILL GRADUALLY IMPROVE
FROM THE NORTH THIS MORNING AND WILL BE VFR ACROSS THE AREA BY ABOUT
20Z. ALBRECHT

KSEA...EXPECT 4-6SM RA BR BKN015-025 OVC035 THROUGH ABOUT 18Z.
CONDITIONS WILL IMPROVE TO P6SM SCT025 BKN050 BY ABOUT 22Z. E WIND
5-7 KT EARLY THIS MORNING WILL BECOME N 7-10 KT AROUND 15Z AND N
12G20KT BY 21Z. ALBRECHT

&&

.MARINE...A BROAD AND DIFFUSE LOW OVER THE WASHINGTON COASTAL WATERS
WILL DROP SOUTH THROUGH THE OREGON COASTAL WATERS TODAY. N TO NE
WINDS 15-25 KT WILL DEVELOP OVER ALL OF THE WATERS THROUGH THIS
AFTERNOON AS THE LOW DEPARTS AND A 1030-1035 MB HIGH DEVELOPS OVER
BRITISH COLUMBIA. PORTIONS OF THE STRAIT OF JUAN DE FUCA...THE
COASTAL WATERS ADJACENT TO THE STRAIT...AND THE NORTHERN INLAND
WATERS MAY SEE LOCAL 30 KT WINDS BY TONIGHT AND EARLY SATURDAY
MORNING. THE ONLY ZONE NOT IN A SMALL CRAFT ADVISORY THROUGH TODAY
WILL BE THE NEAR COASTAL WATERS FROM POINT GRENVILLE TO CAPE
SHOALWATER OUT TO 10 NM...WHERE CONVERGENT NORTH AND NORTHEAST WINDS
IN THAT AREA WILL KNOCK WIND SPEEDS BACK TODAY. A SMALL CRAFT
ADVISORY WILL LIKELY BE NEEDED FOR THAT ZONE TONIGHT.

WINDS WILL DIMINISH AND BECOME LIGHT ON SUN AS A RIDGE OF HIGH PRES
MOVES SE ACROSS THE WATERS. ANOTHER ROUND OF STRONG NE WINDS ARE
POSSIBLE LATER MON INTO TUE AS A 1040 MB HIGH BUILDS OVER BRITISH
COLUMBIA...THEN MOVES BY THE AREA TO THE NE. HOWEVER FORECAST MODELS
ARE TRENDING WEAKER WITH THE OUTFLOW FOR LATER MON INTO TUE. ALBRECHT

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT FOR THE COASTAL WATERS
      FROM POINT GRENVILLE TO CAPE SHOALWATER OUT TO 10 NM.

&&

$$

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







000
FXUS66 KSEW 271059
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 AM PST FRI FEB 27 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL PRODUCE WIDESPREAD SHOWERS
ACROSS WESTERN WASHINGTON TODAY AS IT MOVES SOUTHEAST FROM THE COAST
TOWARD OREGON. A FEW INCHES OF SNOW WILL FALL IN THE MOUNTAINS. AN
UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS AND COOL NIGHTS
THIS WEEKEND. A WEAK SYSTEM WILL MOVE THROUGH SUNDAY NIGHT AND
MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...A SMALL UPPER LOW THAT WAS NEAR THE NORTH TIP OF
VANCOUVER ISLAND MOVED SOUTHEAST INTO THE WASHINGTON COASTAL WATERS
OVERNIGHT. THIS FEATURE PRODUCED WIDESPREAD LIGHT TO MODERATE
SHOWERS ACROSS WESTERN WASHINGTON OVERNIGHT...WITH MORE THAN 0.25
INCH OF PRECIPITATION IN MANY PLACES. AT 2 AM THE SHOWERS WERE
MAINLY IN A BAND OVER THE INTERIOR LOWLANDS WITH TEMPERATURES IN THE
MID 40S TO LOWER 50S.

THE UPPER LOW WILL CONTINUE ITS SOUTHEAST TRACK...MOVING INTO
NORTHWEST OREGON TODAY AND SOUTHEAST OREGON OR NORTHWEST NEVADA
TONIGHT. THE UPPER FLOW OVER WESTERN WASHINGTON WILL VEER TO NORTH
AND THEN NORTHEAST...AND NORTHERLY OFFSHORE LOW LEVEL FLOW WILL
DEVELOP TOO AS SURFACE HIGH PRESSURE MOVES SOUTH ACROSS BRITISH
COLUMBIA.

SHOWERS SHOULD REMAIN FAIRLY WIDESPREAD TODAY...ESPECIALLY THIS
MORNING...BUT THEY WILL DECREASE FROM NORTH TO SOUTH LATE TODAY AND
TONIGHT AS THE DRY AND COOLER NORTHERLY FLOW TAKES OVER. BY LATE
TONIGHT SKIES WILL BE CLEARING...WITH LIGHT SPOTTY SHOWERS LIMITED
TO THE SOUTH PART OF THE FORECAST AREA AND PERHAPS A WEAK
CONVERGENCE ZONE. BREEZY NORTH OR NORTHEAST WINDS WILL DEVELOP
TONIGHT...WITH THE STRONGEST WINDS IN THE NORTH INTERIOR NEAR THE
FRASER RIVER OUTFLOW SOURCE.

THE SNOW LEVEL WILL BE 3000 TO 3500 FT TODAY...THEN FALL SLIGHTLY
TONIGHT AS PRECIPITATION DECREASES. ANOTHER 2 TO 5 INCHES OF SNOW IS
LIKELY IN THE MOUNTAINS WITH THIS SYSTEM...WITH THE HEAVIEST AMOUNTS
IN THE OLYMPICS AND THE CASCADES SOUTH OF SNOQUALMIE PASS.

DRY NORTHERLY FLOW ALOFT WILL PREVAIL SATURDAY FOR A SUNNY DAY.
TEMPERATURES SHOULD CLIMB INTO THE LOWER 50S IN THE LOWLANDS...BUT
NORTHERLY OFFSHORE SURFACE FLOW WILL MAKE FOR BREEZY CONDITIONS
ACROSS MUCH OF THE FORECAST AREA. WINDS SHOULD EASE SATURDAY
NIGHT...WITH OVERNIGHT LOWS IN THE 30S AND LOCALLY BELOW FREEZING
UNDER MOSTLY CLEAR SKIES.

SUNDAY WILL BE ANOTHER DRY AND MOSTLY SUNNY DAY...BUT THE UPPER FLOW
WILL BACK TO NORTHWEST AS A WEAK UPPER SHORTWAVE STARTS APPROACHING
ALONG THE COAST OF BRITISH COLUMBIA. THE SHORTWAVE WILL MOVE ACROSS
WESTERN WASHINGTON SUNDAY NIGHT. IT WILL BRING A CHANCE OF
PRECIPITATION...BUT THE LATEST MODEL RUNS SUGGEST THAT AMOUNTS WILL
BE FAIRLY LIGHT AND COVERAGE MIGHT BE SPOTTY.   MCDONNAL

.LONG TERM...THE UPPER SHORTWAVE THAT MOVES INTO WESTERN WASHINGTON
SUNDAY NIGHT WILL MAINTAIN A CHANCE OF SHOWERS MONDAY AND MONDAY
NIGHT...BUT AGAIN AMOUNTS LOOK LIGHT AND COVERAGE SHOULD BE SPOTTY.
DRY NORTHERLY FLOW WILL TAKE OVER AGAIN TUESDAY AHEAD OF A STRONG
UPPER RIDGE OFFSHORE OUTSIDE OF 130W. THE UPPER RIDGE WILL MOVE
SLOWLY TOWARD THE REGION FOR ANOTHER DRY DAY WEDNESDAY. IT WILL
WEAKEN AS IT MOVES INLAND THURSDAY...AND A WEAK SYSTEM MOVING OVER
THE NORTH SIDE OF THE RIDGE COULD BRING SOME PRECIPITATION TO
WESTERN WASHINGTON. THE MODELS ALL AGREE ON THIS GENERAL SCENARIO.
MCDONNAL

&&

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

&&

.AVIATION...A SURFACE AND UPPER LEVEL LOW IS DROPPING SOUTHWARD
ALONG THE WASHINGTON COAST EARLY THIS MORNING. THE LOW WILL DROPS
SOUTH THROUGH THE COASTAL WATERS OF OREGON TODAY. THE AIR MASS IS
MOIST AND STABLE ACROSS WESTERN WASHINGTON. NORTHEASTERLY FLOW OVER
THE FAR NORTHERN PORTIONS OF THE INTERIOR ARE GIVING VFR CONDITIONS
THERE. ELSEWHERE...RAIN AND LOW LEVEL CONVERGENCE IS GIVING MVFR
CEILINGS AND LOCAL IFR CONDITIONS. CONDITIONS WILL GRADUALLY IMPROVE
FROM THE NORTH THIS MORNING AND WILL BE VFR ACROSS THE AREA BY ABOUT
20Z. ALBRECHT

KSEA...EXPECT 4-6SM RA BR BKN015-025 OVC035 THROUGH ABOUT 18Z.
CONDITIONS WILL IMPROVE TO P6SM SCT025 BKN050 BY ABOUT 22Z. E WIND
5-7 KT EARLY THIS MORNING WILL BECOME N 7-10 KT AROUND 15Z AND N
12G20KT BY 21Z. ALBRECHT

&&

.MARINE...A BROAD AND DIFFUSE LOW OVER THE WASHINGTON COASTAL WATERS
WILL DROP SOUTH THROUGH THE OREGON COASTAL WATERS TODAY. N TO NE
WINDS 15-25 KT WILL DEVELOP OVER ALL OF THE WATERS THROUGH THIS
AFTERNOON AS THE LOW DEPARTS AND A 1030-1035 MB HIGH DEVELOPS OVER
BRITISH COLUMBIA. PORTIONS OF THE STRAIT OF JUAN DE FUCA...THE
COASTAL WATERS ADJACENT TO THE STRAIT...AND THE NORTHERN INLAND
WATERS MAY SEE LOCAL 30 KT WINDS BY TONIGHT AND EARLY SATURDAY
MORNING. THE ONLY ZONE NOT IN A SMALL CRAFT ADVISORY THROUGH TODAY
WILL BE THE NEAR COASTAL WATERS FROM POINT GRENVILLE TO CAPE
SHOALWATER OUT TO 10 NM...WHERE CONVERGENT NORTH AND NORTHEAST WINDS
IN THAT AREA WILL KNOCK WIND SPEEDS BACK TODAY. A SMALL CRAFT
ADVISORY WILL LIKELY BE NEEDED FOR THAT ZONE TONIGHT.

WINDS WILL DIMINISH AND BECOME LIGHT ON SUN AS A RIDGE OF HIGH PRES
MOVES SE ACROSS THE WATERS. ANOTHER ROUND OF STRONG NE WINDS ARE
POSSIBLE LATER MON INTO TUE AS A 1040 MB HIGH BUILDS OVER BRITISH
COLUMBIA...THEN MOVES BY THE AREA TO THE NE. HOWEVER FORECAST MODELS
ARE TRENDING WEAKER WITH THE OUTFLOW FOR LATER MON INTO TUE. ALBRECHT

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY ALL WATERS EXCEPT FOR THE COASTAL WATERS
      FROM POINT GRENVILLE TO CAPE SHOALWATER OUT TO 10 NM.

&&

$$

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








000
FXUS66 KSEW 270458
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PST THU FEB 26 2015

.SYNOPSIS...A LOW PRESSURE SYSTEM WILL BRING RAIN TO MOST OF WESTERN
WASHINGTON THROUGH FRIDAY MORNING BEFORE CHANGING OVER TO SHOWERS. A
FEW INCHES OF SNOW WILL FALL IN THE MOUNTAINS AND POSSIBLY SOME OF
THE PASSES. AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS THIS WEEKEND. A WEAK SYSTEM WILL MOVE THROUGH SUNDAY
NIGHT AND MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...RADAR SHOWS LIGHT TO MODERATE RAIN PUSHING INTO THE
INTERIOR OF WRN WA THIS EVENING AS A LOW PRESSURE SYSTEM APPROACHES.
CLOUD TOP BRIGHTENING ON IR SATELLITE IMAGERY INDICATES THE SYSTEM
IS IN A DEVELOPING PHASE. MSAS ANALYSIS PLACES A 1009 MB CLOSED
SURFACE LOW OFF THE N/CENTRAL WA COAST AT 04Z. MODELS SHOW THE 500
MB TROUGH CLOSING OFF OVERNIGHT AND BECOMING VERTICALLY ALIGNED WITH
A SLIGHTLY DEEPER 1005 MB LOW BY 12Z. THIS PROCESS WILL TEND TO SLOW
THE PROGRESSION OF THE SYSTEM AND HOLD RAINFALL OVER WRN WA LONGER.
HEAVIER RAINFALL AMOUNTS OF A HALF INCH TO ONE INCH WILL FALL WITHIN
THE FAVORED DEFORMATION ZONE TO THE E/NE OF THE CENTRAL LOW
CIRCULATION. HIGH RESOLUTION MODELS GENERALLY AGREE THIS WILL BE
FROM THE COAST THROUGH GREATER PUGET SOUND AND THE SW INTERIOR/S
CASCADES OVER THE NEXT 12 HOURS OR SO. THE N INTERIOR SHOULD HAVE
LIGHTER RAINFALL AMOUNTS. GIVEN THE CURRENT SATELLITE/RADAR
TRENDS...WILL UPDATE THE FORECAST TO CALL IT RAIN RATHER THAN
SHOWERS. WILL ALSO REMOVE THE THUNDERSTORMS GIVEN THE PRECIPITATION
IS MORE STRATIFORM ON RADAR.

SNOW WILL FALL IN THE MOUNTAINS THROUGH FRIDAY MORNING BUT THE
HEAVIEST PRECIPITATION WILL LIKELY BE TO THE W OF THE CASCADES. SNOW
LEVELS WILL FALL FROM ABOUT 4500 FEET TO 3500 FEET FRIDAY MORNING
WITH A FEW INCHES OF SNOW POSSIBLE. HIGHEST AMOUNTS UP TO 5
INCHES...JUST BELOW ADVISORY CRITERIA...WILL LIKELY OCCUR OVER THE
SRN CASCADE ZONE AROUND MT RAINIER.

RAIN TRANSITIONS TO SHOWERS LATE FRIDAY MORNING OR AFTERNOON
DEPENDING ON HOW QUICKLY THE SYSTEM SHIFTS SWD. IT WILL DRY OUT
FASTER ACROSS THE N. SURFACE HIGH PRESSURE BUILDING OVER SRN B.C.
WILL PROVIDE INCREASING NE OFFSHORE FLOW LATER IN THE DAY INTO
FRIDAY NIGHT. LOWER DEW POINT AIR MEANS SHOWERS WILL END. IT ALSO
WILL BECOME BREEZY...ESPECIALLY ACROSS THE N INTERIOR WHERE FRASER
OUTFLOW WILL DEVELOP. THE AIR MASS WILL ALSO BE COOLER AND LOWS WILL
PROBABLY BE IN THE 30S MOST SPOTS SATURDAY MORNING.

DRY WEATHER AND SUNSHINE WILL RETURN TO WRN WA OVER THE WEEKEND. NE
OFFSHORE FLOW WILL HOLD TEMPERATURES BACK SOMEWHAT...BUT STILL NEAR
AVERAGE IN THE LOW 50S. EXPOSED AREAS THAT HAVE BREEZY WINDS WILL
PROBABLY STAY JUST ABOVE FREEZING SATURDAY/SUNDAY MORNINGS.
HOWEVER...SHELTERED LOCATIONS AND THE TYPICAL COLD POCKETS WILL SEE
LOWS NEAR FREEZING AND POSSIBLY DIPPING INTO THE UPPER 20S IN A FEW
SPOTS. MERCER

.LONG TERM...NO UPDATE FROM PREVIOUS DISCUSSION...A WEAK WEATHER
SYSTEM WILL BRING A CHANCE OF RAIN SUNDAY NIGHT THROUGH MONDAY
NIGHT. THE STRENGTH OF THIS SYSTEM HAS BEEN WANING IN RECENT MODEL
RUNS. TUESDAY THROUGH THURSDAY IS LIKELY TO BE A DRY PERIOD...WITH A
CHANCE OF RAIN RETURNING FRIDAY. HIGHS AND LOWS WILL BE SLIGHTLY
BELOW NORMAL. BURKE

&&

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

&&

.AVIATION...A SURFACE AND UPPER LEVEL LOW ALONG WESTERN VANCOUVER
ISLAND WILL DROP SOUTH THROUGH THE COASTAL WATERS TONIGHT AND
THROUGH THE OREGON WATERS ON FRIDAY. THE AIR MASS AROUND THIS LOW IS
MOIST AND SOMEWHAT STABLE. RAIN WRAPPING AROUND THE LOW WILL GIVE
MVFR CIGS AND VSBYS TONIGHT INTO FRIDAY MORNING. CONDITIONS WILL DRY
FROM THE NORTH STARTING MIDDAY FRIDAY AS HIGH PRESSURE AT THE
SURFACE AND ALOFT BUILDS OVER BRITISH COLUMBIA. ALBRECHT

KSEA...EXPECT 3-5SM -RA BR BKN010-015 OVC025 THROUGH 18Z FRI. NE
WIND 3-6 KT WILL BECOME N 7-10 KT AFTER 15Z. ALBRECHT

&&

.MARINE...FORECAST MODELS ARE SHOWING RATHER GOOD CONSISTENCY AND
CONTINUITY THIS EVENING. A WEAK LOW W OF CENTRAL VANCOUVER ISLAND
WILL DROP SOUTH THROUGH THE COASTAL WATERS TONIGHT AND THE OREGON
COASTAL WATERS ON FRI. STRONG OFFSHORE FLOW WILL DEVELOP IN THE WAKE
OF THE LOW AS A 1030-1035 MB HIGH PRES SYSTEM OVER BRITISH COLUMBIA
BUILDS INTO THE AREA FROM THE NORTH.

WINDS WILL DIMINISH AND BECOME LIGHT ON SUN AS A RIDGE OF HIGH PRES
MOVES SE ACROSS THE WATERS. ANOTHER ROUND OF STRONG N TO NE WINDS
ARE EXPECTED LATER MON INTO TUE AS A 1040 MB HIGH BUILDS OVER
BRITISH COLUMBIA...THEN MOVES BY THE AREA TO THE NE.

EXPECT LIGHT WIND TONIGHT. N TO NE WIND WILL INCREASE 20-25 KT ALONG
THE CENTRAL AND SOUTHERN OUTER COASTAL WATERS EARLY FRI MORNING.
SMALL CRAFT ADVISORY N TO NE WINDS WILL SPREAD INTO THE REMAINDER OF
THE COASTAL WATERS AND TO ALL OF THE INLAND WATERS FRI NIGHT INTO
SAT. ALBRECHT

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY STARTING 15Z FRI FOR THE COASTAL WATERS
      FROM JAMES ISLAND TO CAPE SHOALWATER 10-60 NM OFFSHORE.

&&

$$

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









000
FXUS66 KSEW 270458
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PST THU FEB 26 2015

.SYNOPSIS...A LOW PRESSURE SYSTEM WILL BRING RAIN TO MOST OF WESTERN
WASHINGTON THROUGH FRIDAY MORNING BEFORE CHANGING OVER TO SHOWERS. A
FEW INCHES OF SNOW WILL FALL IN THE MOUNTAINS AND POSSIBLY SOME OF
THE PASSES. AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS THIS WEEKEND. A WEAK SYSTEM WILL MOVE THROUGH SUNDAY
NIGHT AND MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...RADAR SHOWS LIGHT TO MODERATE RAIN PUSHING INTO THE
INTERIOR OF WRN WA THIS EVENING AS A LOW PRESSURE SYSTEM APPROACHES.
CLOUD TOP BRIGHTENING ON IR SATELLITE IMAGERY INDICATES THE SYSTEM
IS IN A DEVELOPING PHASE. MSAS ANALYSIS PLACES A 1009 MB CLOSED
SURFACE LOW OFF THE N/CENTRAL WA COAST AT 04Z. MODELS SHOW THE 500
MB TROUGH CLOSING OFF OVERNIGHT AND BECOMING VERTICALLY ALIGNED WITH
A SLIGHTLY DEEPER 1005 MB LOW BY 12Z. THIS PROCESS WILL TEND TO SLOW
THE PROGRESSION OF THE SYSTEM AND HOLD RAINFALL OVER WRN WA LONGER.
HEAVIER RAINFALL AMOUNTS OF A HALF INCH TO ONE INCH WILL FALL WITHIN
THE FAVORED DEFORMATION ZONE TO THE E/NE OF THE CENTRAL LOW
CIRCULATION. HIGH RESOLUTION MODELS GENERALLY AGREE THIS WILL BE
FROM THE COAST THROUGH GREATER PUGET SOUND AND THE SW INTERIOR/S
CASCADES OVER THE NEXT 12 HOURS OR SO. THE N INTERIOR SHOULD HAVE
LIGHTER RAINFALL AMOUNTS. GIVEN THE CURRENT SATELLITE/RADAR
TRENDS...WILL UPDATE THE FORECAST TO CALL IT RAIN RATHER THAN
SHOWERS. WILL ALSO REMOVE THE THUNDERSTORMS GIVEN THE PRECIPITATION
IS MORE STRATIFORM ON RADAR.

SNOW WILL FALL IN THE MOUNTAINS THROUGH FRIDAY MORNING BUT THE
HEAVIEST PRECIPITATION WILL LIKELY BE TO THE W OF THE CASCADES. SNOW
LEVELS WILL FALL FROM ABOUT 4500 FEET TO 3500 FEET FRIDAY MORNING
WITH A FEW INCHES OF SNOW POSSIBLE. HIGHEST AMOUNTS UP TO 5
INCHES...JUST BELOW ADVISORY CRITERIA...WILL LIKELY OCCUR OVER THE
SRN CASCADE ZONE AROUND MT RAINIER.

RAIN TRANSITIONS TO SHOWERS LATE FRIDAY MORNING OR AFTERNOON
DEPENDING ON HOW QUICKLY THE SYSTEM SHIFTS SWD. IT WILL DRY OUT
FASTER ACROSS THE N. SURFACE HIGH PRESSURE BUILDING OVER SRN B.C.
WILL PROVIDE INCREASING NE OFFSHORE FLOW LATER IN THE DAY INTO
FRIDAY NIGHT. LOWER DEW POINT AIR MEANS SHOWERS WILL END. IT ALSO
WILL BECOME BREEZY...ESPECIALLY ACROSS THE N INTERIOR WHERE FRASER
OUTFLOW WILL DEVELOP. THE AIR MASS WILL ALSO BE COOLER AND LOWS WILL
PROBABLY BE IN THE 30S MOST SPOTS SATURDAY MORNING.

DRY WEATHER AND SUNSHINE WILL RETURN TO WRN WA OVER THE WEEKEND. NE
OFFSHORE FLOW WILL HOLD TEMPERATURES BACK SOMEWHAT...BUT STILL NEAR
AVERAGE IN THE LOW 50S. EXPOSED AREAS THAT HAVE BREEZY WINDS WILL
PROBABLY STAY JUST ABOVE FREEZING SATURDAY/SUNDAY MORNINGS.
HOWEVER...SHELTERED LOCATIONS AND THE TYPICAL COLD POCKETS WILL SEE
LOWS NEAR FREEZING AND POSSIBLY DIPPING INTO THE UPPER 20S IN A FEW
SPOTS. MERCER

.LONG TERM...NO UPDATE FROM PREVIOUS DISCUSSION...A WEAK WEATHER
SYSTEM WILL BRING A CHANCE OF RAIN SUNDAY NIGHT THROUGH MONDAY
NIGHT. THE STRENGTH OF THIS SYSTEM HAS BEEN WANING IN RECENT MODEL
RUNS. TUESDAY THROUGH THURSDAY IS LIKELY TO BE A DRY PERIOD...WITH A
CHANCE OF RAIN RETURNING FRIDAY. HIGHS AND LOWS WILL BE SLIGHTLY
BELOW NORMAL. BURKE

&&

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

&&

.AVIATION...A SURFACE AND UPPER LEVEL LOW ALONG WESTERN VANCOUVER
ISLAND WILL DROP SOUTH THROUGH THE COASTAL WATERS TONIGHT AND
THROUGH THE OREGON WATERS ON FRIDAY. THE AIR MASS AROUND THIS LOW IS
MOIST AND SOMEWHAT STABLE. RAIN WRAPPING AROUND THE LOW WILL GIVE
MVFR CIGS AND VSBYS TONIGHT INTO FRIDAY MORNING. CONDITIONS WILL DRY
FROM THE NORTH STARTING MIDDAY FRIDAY AS HIGH PRESSURE AT THE
SURFACE AND ALOFT BUILDS OVER BRITISH COLUMBIA. ALBRECHT

KSEA...EXPECT 3-5SM -RA BR BKN010-015 OVC025 THROUGH 18Z FRI. NE
WIND 3-6 KT WILL BECOME N 7-10 KT AFTER 15Z. ALBRECHT

&&

.MARINE...FORECAST MODELS ARE SHOWING RATHER GOOD CONSISTENCY AND
CONTINUITY THIS EVENING. A WEAK LOW W OF CENTRAL VANCOUVER ISLAND
WILL DROP SOUTH THROUGH THE COASTAL WATERS TONIGHT AND THE OREGON
COASTAL WATERS ON FRI. STRONG OFFSHORE FLOW WILL DEVELOP IN THE WAKE
OF THE LOW AS A 1030-1035 MB HIGH PRES SYSTEM OVER BRITISH COLUMBIA
BUILDS INTO THE AREA FROM THE NORTH.

WINDS WILL DIMINISH AND BECOME LIGHT ON SUN AS A RIDGE OF HIGH PRES
MOVES SE ACROSS THE WATERS. ANOTHER ROUND OF STRONG N TO NE WINDS
ARE EXPECTED LATER MON INTO TUE AS A 1040 MB HIGH BUILDS OVER
BRITISH COLUMBIA...THEN MOVES BY THE AREA TO THE NE.

EXPECT LIGHT WIND TONIGHT. N TO NE WIND WILL INCREASE 20-25 KT ALONG
THE CENTRAL AND SOUTHERN OUTER COASTAL WATERS EARLY FRI MORNING.
SMALL CRAFT ADVISORY N TO NE WINDS WILL SPREAD INTO THE REMAINDER OF
THE COASTAL WATERS AND TO ALL OF THE INLAND WATERS FRI NIGHT INTO
SAT. ALBRECHT

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY STARTING 15Z FRI FOR THE COASTAL WATERS
      FROM JAMES ISLAND TO CAPE SHOALWATER 10-60 NM OFFSHORE.

&&

$$

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









000
FXUS66 KSEW 270458
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PST THU FEB 26 2015

.SYNOPSIS...A LOW PRESSURE SYSTEM WILL BRING RAIN TO MOST OF WESTERN
WASHINGTON THROUGH FRIDAY MORNING BEFORE CHANGING OVER TO SHOWERS. A
FEW INCHES OF SNOW WILL FALL IN THE MOUNTAINS AND POSSIBLY SOME OF
THE PASSES. AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS THIS WEEKEND. A WEAK SYSTEM WILL MOVE THROUGH SUNDAY
NIGHT AND MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...RADAR SHOWS LIGHT TO MODERATE RAIN PUSHING INTO THE
INTERIOR OF WRN WA THIS EVENING AS A LOW PRESSURE SYSTEM APPROACHES.
CLOUD TOP BRIGHTENING ON IR SATELLITE IMAGERY INDICATES THE SYSTEM
IS IN A DEVELOPING PHASE. MSAS ANALYSIS PLACES A 1009 MB CLOSED
SURFACE LOW OFF THE N/CENTRAL WA COAST AT 04Z. MODELS SHOW THE 500
MB TROUGH CLOSING OFF OVERNIGHT AND BECOMING VERTICALLY ALIGNED WITH
A SLIGHTLY DEEPER 1005 MB LOW BY 12Z. THIS PROCESS WILL TEND TO SLOW
THE PROGRESSION OF THE SYSTEM AND HOLD RAINFALL OVER WRN WA LONGER.
HEAVIER RAINFALL AMOUNTS OF A HALF INCH TO ONE INCH WILL FALL WITHIN
THE FAVORED DEFORMATION ZONE TO THE E/NE OF THE CENTRAL LOW
CIRCULATION. HIGH RESOLUTION MODELS GENERALLY AGREE THIS WILL BE
FROM THE COAST THROUGH GREATER PUGET SOUND AND THE SW INTERIOR/S
CASCADES OVER THE NEXT 12 HOURS OR SO. THE N INTERIOR SHOULD HAVE
LIGHTER RAINFALL AMOUNTS. GIVEN THE CURRENT SATELLITE/RADAR
TRENDS...WILL UPDATE THE FORECAST TO CALL IT RAIN RATHER THAN
SHOWERS. WILL ALSO REMOVE THE THUNDERSTORMS GIVEN THE PRECIPITATION
IS MORE STRATIFORM ON RADAR.

SNOW WILL FALL IN THE MOUNTAINS THROUGH FRIDAY MORNING BUT THE
HEAVIEST PRECIPITATION WILL LIKELY BE TO THE W OF THE CASCADES. SNOW
LEVELS WILL FALL FROM ABOUT 4500 FEET TO 3500 FEET FRIDAY MORNING
WITH A FEW INCHES OF SNOW POSSIBLE. HIGHEST AMOUNTS UP TO 5
INCHES...JUST BELOW ADVISORY CRITERIA...WILL LIKELY OCCUR OVER THE
SRN CASCADE ZONE AROUND MT RAINIER.

RAIN TRANSITIONS TO SHOWERS LATE FRIDAY MORNING OR AFTERNOON
DEPENDING ON HOW QUICKLY THE SYSTEM SHIFTS SWD. IT WILL DRY OUT
FASTER ACROSS THE N. SURFACE HIGH PRESSURE BUILDING OVER SRN B.C.
WILL PROVIDE INCREASING NE OFFSHORE FLOW LATER IN THE DAY INTO
FRIDAY NIGHT. LOWER DEW POINT AIR MEANS SHOWERS WILL END. IT ALSO
WILL BECOME BREEZY...ESPECIALLY ACROSS THE N INTERIOR WHERE FRASER
OUTFLOW WILL DEVELOP. THE AIR MASS WILL ALSO BE COOLER AND LOWS WILL
PROBABLY BE IN THE 30S MOST SPOTS SATURDAY MORNING.

DRY WEATHER AND SUNSHINE WILL RETURN TO WRN WA OVER THE WEEKEND. NE
OFFSHORE FLOW WILL HOLD TEMPERATURES BACK SOMEWHAT...BUT STILL NEAR
AVERAGE IN THE LOW 50S. EXPOSED AREAS THAT HAVE BREEZY WINDS WILL
PROBABLY STAY JUST ABOVE FREEZING SATURDAY/SUNDAY MORNINGS.
HOWEVER...SHELTERED LOCATIONS AND THE TYPICAL COLD POCKETS WILL SEE
LOWS NEAR FREEZING AND POSSIBLY DIPPING INTO THE UPPER 20S IN A FEW
SPOTS. MERCER

.LONG TERM...NO UPDATE FROM PREVIOUS DISCUSSION...A WEAK WEATHER
SYSTEM WILL BRING A CHANCE OF RAIN SUNDAY NIGHT THROUGH MONDAY
NIGHT. THE STRENGTH OF THIS SYSTEM HAS BEEN WANING IN RECENT MODEL
RUNS. TUESDAY THROUGH THURSDAY IS LIKELY TO BE A DRY PERIOD...WITH A
CHANCE OF RAIN RETURNING FRIDAY. HIGHS AND LOWS WILL BE SLIGHTLY
BELOW NORMAL. BURKE

&&

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

&&

.AVIATION...A SURFACE AND UPPER LEVEL LOW ALONG WESTERN VANCOUVER
ISLAND WILL DROP SOUTH THROUGH THE COASTAL WATERS TONIGHT AND
THROUGH THE OREGON WATERS ON FRIDAY. THE AIR MASS AROUND THIS LOW IS
MOIST AND SOMEWHAT STABLE. RAIN WRAPPING AROUND THE LOW WILL GIVE
MVFR CIGS AND VSBYS TONIGHT INTO FRIDAY MORNING. CONDITIONS WILL DRY
FROM THE NORTH STARTING MIDDAY FRIDAY AS HIGH PRESSURE AT THE
SURFACE AND ALOFT BUILDS OVER BRITISH COLUMBIA. ALBRECHT

KSEA...EXPECT 3-5SM -RA BR BKN010-015 OVC025 THROUGH 18Z FRI. NE
WIND 3-6 KT WILL BECOME N 7-10 KT AFTER 15Z. ALBRECHT

&&

.MARINE...FORECAST MODELS ARE SHOWING RATHER GOOD CONSISTENCY AND
CONTINUITY THIS EVENING. A WEAK LOW W OF CENTRAL VANCOUVER ISLAND
WILL DROP SOUTH THROUGH THE COASTAL WATERS TONIGHT AND THE OREGON
COASTAL WATERS ON FRI. STRONG OFFSHORE FLOW WILL DEVELOP IN THE WAKE
OF THE LOW AS A 1030-1035 MB HIGH PRES SYSTEM OVER BRITISH COLUMBIA
BUILDS INTO THE AREA FROM THE NORTH.

WINDS WILL DIMINISH AND BECOME LIGHT ON SUN AS A RIDGE OF HIGH PRES
MOVES SE ACROSS THE WATERS. ANOTHER ROUND OF STRONG N TO NE WINDS
ARE EXPECTED LATER MON INTO TUE AS A 1040 MB HIGH BUILDS OVER
BRITISH COLUMBIA...THEN MOVES BY THE AREA TO THE NE.

EXPECT LIGHT WIND TONIGHT. N TO NE WIND WILL INCREASE 20-25 KT ALONG
THE CENTRAL AND SOUTHERN OUTER COASTAL WATERS EARLY FRI MORNING.
SMALL CRAFT ADVISORY N TO NE WINDS WILL SPREAD INTO THE REMAINDER OF
THE COASTAL WATERS AND TO ALL OF THE INLAND WATERS FRI NIGHT INTO
SAT. ALBRECHT

&&

.SEW WATCHES/WARNINGS/ADVISORIES...
WA...NONE.
PZ...SMALL CRAFT ADVISORY STARTING 15Z FRI FOR THE COASTAL WATERS
      FROM JAMES ISLAND TO CAPE SHOALWATER 10-60 NM OFFSHORE.

&&

$$

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










000
FXUS66 KSEW 262256
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PST THU FEB 26 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL PRODUCE SCATTERED SHOWERS
ACROSS WESTERN WASHINGTON THROUGH FRIDAY...ESPECIALLY AT THE COAST
AND IN THE SOUTHWEST. A FEW INCHES OF SNOW WILL FALL IN THE
MOUNTAINS. AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS THIS WEEKEND. A WEAK SYSTEM WILL MOVE THROUGH SUNDAY
NIGHT AND MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...AN UPPER LEVEL CLOSED LOW WILL MOVE SOUTH ALONG THE
COAST TONIGHT AND INTO OREGON FRIDAY. THIS WILL BRING SHOWERS TO THE
AREA WITH MORE NUMEROUS SHOWERS ALONG THE COAST AND IN THE OLYMPICS.
THERE IS A CHANCE OF THUNDERSTORMS ALONG THE COAST LATE TONIGHT AND
FRIDAY. BY FRIDAY AFTERNOON THE SHOWER CHANCE WILL BE DECREASING
ESPECIALLY OVER THE NORTH. HIGHS FRIDAY WILL BE IN THE LOW 50S.

THERE WILL BE SOME SNOW IN THE OLYMPICS AND SOUTHERN PART OF THE
CASCADES. AMOUNTS WILL PROBABLY BE UP TO SIX INCHES OVER HIGHER
TERRAIN. THE AVALANCHE UNIT THINKS IT COULD BE UP TO EIGHT INCHES
AND THAT A SNOW ADVISORY MIGHT BE NEEDED...BUT WILL LEAVE THAT UP TO
LATER SHIFTS.

COLD DRY AIR WILL BEGIN TO SPILL OUT OF BRITISH COLUMBIA INTO
WESTERN WASHINGTON FRIDAY NIGHT. SKIES WILL CLEAR FROM NORTH TO
SOUTH ON FRIDAY NIGHT AND SATURDAY. BY SATURDAY AFTERNOON SKIES WILL
BE CLEAR. BREEZY CONDITIONS WILL BE COMMON AS THE COLD AIR ADVANCES.
THE NORTH INTERIOR COULD BE WINDY AT TIMES. HIGHS ON SATURDAY WILL
BE A FEW DEGREES LOWER THAN FRIDAY...WITH NOT MUCH AFTERNOON HEATING
AS COLD AIR MOVES OVER THE AREA.

ON SUNDAY THE COOL DRY AIR MASS WILL REMAIN OVER THE AREA. OVERNIGHT
LOWS BOTH SATURDAY NIGHT AND SUNDAY NIGHT WILL BE IN THE 30S WITH
SHELTERED LOCATIONS LIKELY TO FALL BELOW FREEZING. BURKE

.LONG TERM...A WEAK WEATHER SYSTEM WILL BRING A CHANCE OF RAIN
SUNDAY NIGHT THROUGH MONDAY NIGHT. THE STRENGTH OF THIS SYSTEM HAS
BEEN WANING IN RECENT MODEL RUNS. TUESDAY THROUGH THURSDAY IS LIKELY
TO BE A DRY PERIOD...WITH A CHANCE OF RAIN RETURNING FRIDAY. HIGHS
AND LOWS WILL BE SLIGHTLY BELOW NORMAL. BURKE

&&

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

&&

.AVIATION...A LOW PRESSURE SYSTEM MOVING SOUTHEAST FROM THE B.C.
COASTAL WATERS WILL BRING SHOWERS TO WESTERN WA TONIGHT. NORTHERLY
FLOW WILL DEVELOP FRIDAY AFTERNOON AND EVENING AS THE LOW MOVES
SOUTH AND HIGH PRESSURE BUILDS OVER BRITISH COLUMBIA. THE AIR WILL
BE MOIST AND BECOME UNSTABLE OVERNIGHT...THEN DRY AND STABILIZE LATE
FRIDAY WITH CLEARING FRIDAY NIGHT.

KSEA...SHOWERS WILL INCREASE TONIGHT AS A WEATHER SYSTEM MOVES
THROUGH THE AREA. LIGHT AND VARIABLE WINDS WILL BECOME NORTHERLY AND
INCREASE FRIDAY.

&&

.MARINE...A WEAK FRONTAL SYSTEM AND LOW PRESSURE AREA WILL MOVE FROM
THE B.C. COASTAL WATERS SE THROUGH WESTERN WA TONIGHT. PRESSURE
GRADIENTS ARE EXPECTED TO REMAIN LIGHT OVER THE WATERS THROUGH EARLY
FRI. HIGH PRES WILL BUILD OVER THE INTERIOR OF BRITISH COLUMBIA FRI
AND FRI NIGHT AND AS THE LOW MOVES SOUTH OUT OF THE AREA N TO NE
FLOW WILL INCREASE LATER FRI. SMALL CRAFT ADVISORY CONDITIONS ARE
LIKELY OVER MOST OF THE WATERS STARTING AROUND FRI AFTERNOON THROUGH
ABOUT SAT MORNING. HIGH PRES WILL MOVE OVER THE WATERS SUNDAY GIVING
LIGHT WINDS. ANOTHER LOW WILL DROP SOUTHEAST ACROSS THE AREA SUN
NIGHT AND MON...FOLLOWED AGAIN BY NE WINDS AS HIGH PRESSURE
BUILDS OVER B.C. MON AND TUE.

&&

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

&&

$$

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






000
FXUS66 KSEW 262256
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PST THU FEB 26 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL PRODUCE SCATTERED SHOWERS
ACROSS WESTERN WASHINGTON THROUGH FRIDAY...ESPECIALLY AT THE COAST
AND IN THE SOUTHWEST. A FEW INCHES OF SNOW WILL FALL IN THE
MOUNTAINS. AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS THIS WEEKEND. A WEAK SYSTEM WILL MOVE THROUGH SUNDAY
NIGHT AND MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...AN UPPER LEVEL CLOSED LOW WILL MOVE SOUTH ALONG THE
COAST TONIGHT AND INTO OREGON FRIDAY. THIS WILL BRING SHOWERS TO THE
AREA WITH MORE NUMEROUS SHOWERS ALONG THE COAST AND IN THE OLYMPICS.
THERE IS A CHANCE OF THUNDERSTORMS ALONG THE COAST LATE TONIGHT AND
FRIDAY. BY FRIDAY AFTERNOON THE SHOWER CHANCE WILL BE DECREASING
ESPECIALLY OVER THE NORTH. HIGHS FRIDAY WILL BE IN THE LOW 50S.

THERE WILL BE SOME SNOW IN THE OLYMPICS AND SOUTHERN PART OF THE
CASCADES. AMOUNTS WILL PROBABLY BE UP TO SIX INCHES OVER HIGHER
TERRAIN. THE AVALANCHE UNIT THINKS IT COULD BE UP TO EIGHT INCHES
AND THAT A SNOW ADVISORY MIGHT BE NEEDED...BUT WILL LEAVE THAT UP TO
LATER SHIFTS.

COLD DRY AIR WILL BEGIN TO SPILL OUT OF BRITISH COLUMBIA INTO
WESTERN WASHINGTON FRIDAY NIGHT. SKIES WILL CLEAR FROM NORTH TO
SOUTH ON FRIDAY NIGHT AND SATURDAY. BY SATURDAY AFTERNOON SKIES WILL
BE CLEAR. BREEZY CONDITIONS WILL BE COMMON AS THE COLD AIR ADVANCES.
THE NORTH INTERIOR COULD BE WINDY AT TIMES. HIGHS ON SATURDAY WILL
BE A FEW DEGREES LOWER THAN FRIDAY...WITH NOT MUCH AFTERNOON HEATING
AS COLD AIR MOVES OVER THE AREA.

ON SUNDAY THE COOL DRY AIR MASS WILL REMAIN OVER THE AREA. OVERNIGHT
LOWS BOTH SATURDAY NIGHT AND SUNDAY NIGHT WILL BE IN THE 30S WITH
SHELTERED LOCATIONS LIKELY TO FALL BELOW FREEZING. BURKE

.LONG TERM...A WEAK WEATHER SYSTEM WILL BRING A CHANCE OF RAIN
SUNDAY NIGHT THROUGH MONDAY NIGHT. THE STRENGTH OF THIS SYSTEM HAS
BEEN WANING IN RECENT MODEL RUNS. TUESDAY THROUGH THURSDAY IS LIKELY
TO BE A DRY PERIOD...WITH A CHANCE OF RAIN RETURNING FRIDAY. HIGHS
AND LOWS WILL BE SLIGHTLY BELOW NORMAL. BURKE

&&

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

&&

.AVIATION...A LOW PRESSURE SYSTEM MOVING SOUTHEAST FROM THE B.C.
COASTAL WATERS WILL BRING SHOWERS TO WESTERN WA TONIGHT. NORTHERLY
FLOW WILL DEVELOP FRIDAY AFTERNOON AND EVENING AS THE LOW MOVES
SOUTH AND HIGH PRESSURE BUILDS OVER BRITISH COLUMBIA. THE AIR WILL
BE MOIST AND BECOME UNSTABLE OVERNIGHT...THEN DRY AND STABILIZE LATE
FRIDAY WITH CLEARING FRIDAY NIGHT.

KSEA...SHOWERS WILL INCREASE TONIGHT AS A WEATHER SYSTEM MOVES
THROUGH THE AREA. LIGHT AND VARIABLE WINDS WILL BECOME NORTHERLY AND
INCREASE FRIDAY.

&&

.MARINE...A WEAK FRONTAL SYSTEM AND LOW PRESSURE AREA WILL MOVE FROM
THE B.C. COASTAL WATERS SE THROUGH WESTERN WA TONIGHT. PRESSURE
GRADIENTS ARE EXPECTED TO REMAIN LIGHT OVER THE WATERS THROUGH EARLY
FRI. HIGH PRES WILL BUILD OVER THE INTERIOR OF BRITISH COLUMBIA FRI
AND FRI NIGHT AND AS THE LOW MOVES SOUTH OUT OF THE AREA N TO NE
FLOW WILL INCREASE LATER FRI. SMALL CRAFT ADVISORY CONDITIONS ARE
LIKELY OVER MOST OF THE WATERS STARTING AROUND FRI AFTERNOON THROUGH
ABOUT SAT MORNING. HIGH PRES WILL MOVE OVER THE WATERS SUNDAY GIVING
LIGHT WINDS. ANOTHER LOW WILL DROP SOUTHEAST ACROSS THE AREA SUN
NIGHT AND MON...FOLLOWED AGAIN BY NE WINDS AS HIGH PRESSURE
BUILDS OVER B.C. MON AND TUE.

&&

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

&&

$$

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







000
FXUS66 KSEW 262256
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 PM PST THU FEB 26 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL PRODUCE SCATTERED SHOWERS
ACROSS WESTERN WASHINGTON THROUGH FRIDAY...ESPECIALLY AT THE COAST
AND IN THE SOUTHWEST. A FEW INCHES OF SNOW WILL FALL IN THE
MOUNTAINS. AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS THIS WEEKEND. A WEAK SYSTEM WILL MOVE THROUGH SUNDAY
NIGHT AND MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...AN UPPER LEVEL CLOSED LOW WILL MOVE SOUTH ALONG THE
COAST TONIGHT AND INTO OREGON FRIDAY. THIS WILL BRING SHOWERS TO THE
AREA WITH MORE NUMEROUS SHOWERS ALONG THE COAST AND IN THE OLYMPICS.
THERE IS A CHANCE OF THUNDERSTORMS ALONG THE COAST LATE TONIGHT AND
FRIDAY. BY FRIDAY AFTERNOON THE SHOWER CHANCE WILL BE DECREASING
ESPECIALLY OVER THE NORTH. HIGHS FRIDAY WILL BE IN THE LOW 50S.

THERE WILL BE SOME SNOW IN THE OLYMPICS AND SOUTHERN PART OF THE
CASCADES. AMOUNTS WILL PROBABLY BE UP TO SIX INCHES OVER HIGHER
TERRAIN. THE AVALANCHE UNIT THINKS IT COULD BE UP TO EIGHT INCHES
AND THAT A SNOW ADVISORY MIGHT BE NEEDED...BUT WILL LEAVE THAT UP TO
LATER SHIFTS.

COLD DRY AIR WILL BEGIN TO SPILL OUT OF BRITISH COLUMBIA INTO
WESTERN WASHINGTON FRIDAY NIGHT. SKIES WILL CLEAR FROM NORTH TO
SOUTH ON FRIDAY NIGHT AND SATURDAY. BY SATURDAY AFTERNOON SKIES WILL
BE CLEAR. BREEZY CONDITIONS WILL BE COMMON AS THE COLD AIR ADVANCES.
THE NORTH INTERIOR COULD BE WINDY AT TIMES. HIGHS ON SATURDAY WILL
BE A FEW DEGREES LOWER THAN FRIDAY...WITH NOT MUCH AFTERNOON HEATING
AS COLD AIR MOVES OVER THE AREA.

ON SUNDAY THE COOL DRY AIR MASS WILL REMAIN OVER THE AREA. OVERNIGHT
LOWS BOTH SATURDAY NIGHT AND SUNDAY NIGHT WILL BE IN THE 30S WITH
SHELTERED LOCATIONS LIKELY TO FALL BELOW FREEZING. BURKE

.LONG TERM...A WEAK WEATHER SYSTEM WILL BRING A CHANCE OF RAIN
SUNDAY NIGHT THROUGH MONDAY NIGHT. THE STRENGTH OF THIS SYSTEM HAS
BEEN WANING IN RECENT MODEL RUNS. TUESDAY THROUGH THURSDAY IS LIKELY
TO BE A DRY PERIOD...WITH A CHANCE OF RAIN RETURNING FRIDAY. HIGHS
AND LOWS WILL BE SLIGHTLY BELOW NORMAL. BURKE

&&

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

&&

.AVIATION...A LOW PRESSURE SYSTEM MOVING SOUTHEAST FROM THE B.C.
COASTAL WATERS WILL BRING SHOWERS TO WESTERN WA TONIGHT. NORTHERLY
FLOW WILL DEVELOP FRIDAY AFTERNOON AND EVENING AS THE LOW MOVES
SOUTH AND HIGH PRESSURE BUILDS OVER BRITISH COLUMBIA. THE AIR WILL
BE MOIST AND BECOME UNSTABLE OVERNIGHT...THEN DRY AND STABILIZE LATE
FRIDAY WITH CLEARING FRIDAY NIGHT.

KSEA...SHOWERS WILL INCREASE TONIGHT AS A WEATHER SYSTEM MOVES
THROUGH THE AREA. LIGHT AND VARIABLE WINDS WILL BECOME NORTHERLY AND
INCREASE FRIDAY.

&&

.MARINE...A WEAK FRONTAL SYSTEM AND LOW PRESSURE AREA WILL MOVE FROM
THE B.C. COASTAL WATERS SE THROUGH WESTERN WA TONIGHT. PRESSURE
GRADIENTS ARE EXPECTED TO REMAIN LIGHT OVER THE WATERS THROUGH EARLY
FRI. HIGH PRES WILL BUILD OVER THE INTERIOR OF BRITISH COLUMBIA FRI
AND FRI NIGHT AND AS THE LOW MOVES SOUTH OUT OF THE AREA N TO NE
FLOW WILL INCREASE LATER FRI. SMALL CRAFT ADVISORY CONDITIONS ARE
LIKELY OVER MOST OF THE WATERS STARTING AROUND FRI AFTERNOON THROUGH
ABOUT SAT MORNING. HIGH PRES WILL MOVE OVER THE WATERS SUNDAY GIVING
LIGHT WINDS. ANOTHER LOW WILL DROP SOUTHEAST ACROSS THE AREA SUN
NIGHT AND MON...FOLLOWED AGAIN BY NE WINDS AS HIGH PRESSURE
BUILDS OVER B.C. MON AND TUE.

&&

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

&&

$$

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






000
FXUS66 KSEW 261647
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
845 AM PST THU FEB 26 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL PRODUCE SCATTERED SHOWERS
ACROSS WESTERN WASHINGTON TODAY THROUGH FRIDAY...ESPECIALLY AT THE
COAST AND IN THE SOUTHWEST. A FEW INCHES OF SNOW WILL FALL IN THE
MOUNTAINS. AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS THIS WEEKEND. A WEAK SYSTEM WILL MOVE THROUGH SUNDAY
NIGHT AND MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...THE PREDOMINANT WEATHER AROUND WESTERN WASHINGTON THIS
MORNING APPEARS TO BE FOG...OR AT LEAST MIST...WHICH APPEARS IN MANY
OBSERVATIONS. THERE IS ALSO SOME DRIZZLE. MODELS STILL SHOW SOME
ENHANCEMENT OF SHOWERS THIS AFTERNOON AS AN UPPER LEVEL LOW
APPROACHES FROM THE NORTHWEST. THERE APPEAR TO BE SEVERAL CLOUD
LAYERS UP TO 10K FEET. HIGHS TODAY WILL BE IN THE LOW 50S.

THE UPPER LEVEL LOW WILL MOVE SOUTH ALONG THE COAST TONIGHT AND INTO
OREGON FRIDAY. THERE WILL BE SHOWERS ASSOCIATED WITH THIS LOW...WITH
THE MOST SHOWERS ON THE COAST AND OVER THE SOUTHWEST. STARTING
FRIDAY NIGHT COLDER SURFACE AIR WILL MOVE SOUTH OUT OF BRITISH
COLUMBIA INTO WASHINGTON. THIS WILL CLEAR THE SHOWERS AND CLOUDS OUT
OF THE AREA FROM NORTH TO SOUTH. SATURDAY WILL BE CLEAR AND COOL.
HIGHS ON FRIDAY WILL BE IN THE LOW 50S AND WILL DIP TO AROUND 50 ON
SATURDAY. TEMPERATURES COULD FALL BELOW FREEZING SATURDAY NIGHT IN
WIND SHELTERED SPOTS. BURKE

.LONG TERM...PREVIOUS DISCUSSION...SUNDAY SHOULD BE ANOTHER DRY AND
SUNNY DAY...BUT THE UPPER FLOW WILL BACK TO NORTHWEST AS AN UPPER
SHORTWAVE STARTS DIGGING SOUTH ALONG THE COAST OF BRITISH COLUMBIA.
THAT SYSTEM WILL MOVE ACROSS THE FORECAST AREA SUNDAY NIGHT AND
MONDAY...PROBABLY BRINGING AREAS OF LIGHT PRECIPITATION TO WESTERN
WASHINGTON. THE SNOW LEVEL WILL BE AROUND 2000 TO 3000 FT. DRY
NORTHERLY FLOW WILL RESUME TUESDAY AND WEDNESDAY. OF COURSE THERE
ARE SOME DIFFERENCES IN THE LONGER RANGE MODELS...BUT THEY ALL
INDICATE THIS SAME BASIC PATTERN.   MCDONNAL

&&

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

&&

.AVIATION...AN UPPER TROUGH WILL DEVELOP OVER THE WEST COAST OF
NORTH AMERICA THROUGH FRIDAY. SURFACE LOW PRESSURE WILL SHIFT FROM
THE B.C. COASTAL WATERS TODAY TO THE WA COAST TONIGHT. THE LOW
PRESSURE AREA WILL CONTINUE SOUTH INTO THE GREAT BASIN BY THE
WEEKEND AS HIGH PRESSURE BUILDS OVER BRITISH COLUMBIA. MOIST AIR AND
SHOWERS THROUGH TONIGHT WILL GIVE WAY TO NORTHERLY FLOW AND CLEARING
BY FRIDAY NIGHT.

KSEA...SHOWERY CLOUDY WEATHER WILL CONTINUE THROUGH TONIGHT AND THEN
NORTHERLY WINDS AND CLEARING WILL DEVELOP STARTING AROUND FRIDAY
AFTERNOON.

&&

.MARINE...A WEAK FRONTAL SYSTEM WILL STALL AS IT MOVES ONTO THE
COAST THIS EVENING. THEN A DIFFUSE AND BROAD 1008 MB LOW WILL DROP
SSE FROM THE QUEEN CHARLOTTE SOUND INTO THE COASTAL WATERS TONIGHT.
PRESSURE GRADIENTS ARE EXPECTED TO REMAIN LIGHT OVER THE WATERS
THROUGH EARLY FRI. HIGH PRES WILL BUILD OVER THE INTERIOR OF BRITISH
COLUMBIA FRIDAY. AS THE LOW LATE TONIGHT PASSES SOUTH OF THE AREA
EXPECT N TO NE FLOW TO INCREASE. SMALL CRAFT ADVISORY CONDITIONS ARE
LIKELY OVER MOST OF THE WATERS LATER FRI OR FRI NIGHT INTO SAT. HIGH
PRES WILL MOVE INTO THE WATERS SUNDAY GIVING LIGHT WINDS. ANOTHER
LOW WILL DROP SOUTHEAST ACROSS THE AREA SUN NIGHT AND MONDAY...AGAIN
FOLLOWED BY NE WINDS AS HIGH PRESSURE BUILDS OVER B.C.

&&

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

&&

$$

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







000
FXUS66 KSEW 261647
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
845 AM PST THU FEB 26 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL PRODUCE SCATTERED SHOWERS
ACROSS WESTERN WASHINGTON TODAY THROUGH FRIDAY...ESPECIALLY AT THE
COAST AND IN THE SOUTHWEST. A FEW INCHES OF SNOW WILL FALL IN THE
MOUNTAINS. AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS THIS WEEKEND. A WEAK SYSTEM WILL MOVE THROUGH SUNDAY
NIGHT AND MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...THE PREDOMINANT WEATHER AROUND WESTERN WASHINGTON THIS
MORNING APPEARS TO BE FOG...OR AT LEAST MIST...WHICH APPEARS IN MANY
OBSERVATIONS. THERE IS ALSO SOME DRIZZLE. MODELS STILL SHOW SOME
ENHANCEMENT OF SHOWERS THIS AFTERNOON AS AN UPPER LEVEL LOW
APPROACHES FROM THE NORTHWEST. THERE APPEAR TO BE SEVERAL CLOUD
LAYERS UP TO 10K FEET. HIGHS TODAY WILL BE IN THE LOW 50S.

THE UPPER LEVEL LOW WILL MOVE SOUTH ALONG THE COAST TONIGHT AND INTO
OREGON FRIDAY. THERE WILL BE SHOWERS ASSOCIATED WITH THIS LOW...WITH
THE MOST SHOWERS ON THE COAST AND OVER THE SOUTHWEST. STARTING
FRIDAY NIGHT COLDER SURFACE AIR WILL MOVE SOUTH OUT OF BRITISH
COLUMBIA INTO WASHINGTON. THIS WILL CLEAR THE SHOWERS AND CLOUDS OUT
OF THE AREA FROM NORTH TO SOUTH. SATURDAY WILL BE CLEAR AND COOL.
HIGHS ON FRIDAY WILL BE IN THE LOW 50S AND WILL DIP TO AROUND 50 ON
SATURDAY. TEMPERATURES COULD FALL BELOW FREEZING SATURDAY NIGHT IN
WIND SHELTERED SPOTS. BURKE

.LONG TERM...PREVIOUS DISCUSSION...SUNDAY SHOULD BE ANOTHER DRY AND
SUNNY DAY...BUT THE UPPER FLOW WILL BACK TO NORTHWEST AS AN UPPER
SHORTWAVE STARTS DIGGING SOUTH ALONG THE COAST OF BRITISH COLUMBIA.
THAT SYSTEM WILL MOVE ACROSS THE FORECAST AREA SUNDAY NIGHT AND
MONDAY...PROBABLY BRINGING AREAS OF LIGHT PRECIPITATION TO WESTERN
WASHINGTON. THE SNOW LEVEL WILL BE AROUND 2000 TO 3000 FT. DRY
NORTHERLY FLOW WILL RESUME TUESDAY AND WEDNESDAY. OF COURSE THERE
ARE SOME DIFFERENCES IN THE LONGER RANGE MODELS...BUT THEY ALL
INDICATE THIS SAME BASIC PATTERN.   MCDONNAL

&&

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

&&

.AVIATION...AN UPPER TROUGH WILL DEVELOP OVER THE WEST COAST OF
NORTH AMERICA THROUGH FRIDAY. SURFACE LOW PRESSURE WILL SHIFT FROM
THE B.C. COASTAL WATERS TODAY TO THE WA COAST TONIGHT. THE LOW
PRESSURE AREA WILL CONTINUE SOUTH INTO THE GREAT BASIN BY THE
WEEKEND AS HIGH PRESSURE BUILDS OVER BRITISH COLUMBIA. MOIST AIR AND
SHOWERS THROUGH TONIGHT WILL GIVE WAY TO NORTHERLY FLOW AND CLEARING
BY FRIDAY NIGHT.

KSEA...SHOWERY CLOUDY WEATHER WILL CONTINUE THROUGH TONIGHT AND THEN
NORTHERLY WINDS AND CLEARING WILL DEVELOP STARTING AROUND FRIDAY
AFTERNOON.

&&

.MARINE...A WEAK FRONTAL SYSTEM WILL STALL AS IT MOVES ONTO THE
COAST THIS EVENING. THEN A DIFFUSE AND BROAD 1008 MB LOW WILL DROP
SSE FROM THE QUEEN CHARLOTTE SOUND INTO THE COASTAL WATERS TONIGHT.
PRESSURE GRADIENTS ARE EXPECTED TO REMAIN LIGHT OVER THE WATERS
THROUGH EARLY FRI. HIGH PRES WILL BUILD OVER THE INTERIOR OF BRITISH
COLUMBIA FRIDAY. AS THE LOW LATE TONIGHT PASSES SOUTH OF THE AREA
EXPECT N TO NE FLOW TO INCREASE. SMALL CRAFT ADVISORY CONDITIONS ARE
LIKELY OVER MOST OF THE WATERS LATER FRI OR FRI NIGHT INTO SAT. HIGH
PRES WILL MOVE INTO THE WATERS SUNDAY GIVING LIGHT WINDS. ANOTHER
LOW WILL DROP SOUTHEAST ACROSS THE AREA SUN NIGHT AND MONDAY...AGAIN
FOLLOWED BY NE WINDS AS HIGH PRESSURE BUILDS OVER B.C.

&&

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

&&

$$

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






000
FXUS66 KSEW 261647
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
845 AM PST THU FEB 26 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL PRODUCE SCATTERED SHOWERS
ACROSS WESTERN WASHINGTON TODAY THROUGH FRIDAY...ESPECIALLY AT THE
COAST AND IN THE SOUTHWEST. A FEW INCHES OF SNOW WILL FALL IN THE
MOUNTAINS. AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS THIS WEEKEND. A WEAK SYSTEM WILL MOVE THROUGH SUNDAY
NIGHT AND MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...THE PREDOMINANT WEATHER AROUND WESTERN WASHINGTON THIS
MORNING APPEARS TO BE FOG...OR AT LEAST MIST...WHICH APPEARS IN MANY
OBSERVATIONS. THERE IS ALSO SOME DRIZZLE. MODELS STILL SHOW SOME
ENHANCEMENT OF SHOWERS THIS AFTERNOON AS AN UPPER LEVEL LOW
APPROACHES FROM THE NORTHWEST. THERE APPEAR TO BE SEVERAL CLOUD
LAYERS UP TO 10K FEET. HIGHS TODAY WILL BE IN THE LOW 50S.

THE UPPER LEVEL LOW WILL MOVE SOUTH ALONG THE COAST TONIGHT AND INTO
OREGON FRIDAY. THERE WILL BE SHOWERS ASSOCIATED WITH THIS LOW...WITH
THE MOST SHOWERS ON THE COAST AND OVER THE SOUTHWEST. STARTING
FRIDAY NIGHT COLDER SURFACE AIR WILL MOVE SOUTH OUT OF BRITISH
COLUMBIA INTO WASHINGTON. THIS WILL CLEAR THE SHOWERS AND CLOUDS OUT
OF THE AREA FROM NORTH TO SOUTH. SATURDAY WILL BE CLEAR AND COOL.
HIGHS ON FRIDAY WILL BE IN THE LOW 50S AND WILL DIP TO AROUND 50 ON
SATURDAY. TEMPERATURES COULD FALL BELOW FREEZING SATURDAY NIGHT IN
WIND SHELTERED SPOTS. BURKE

.LONG TERM...PREVIOUS DISCUSSION...SUNDAY SHOULD BE ANOTHER DRY AND
SUNNY DAY...BUT THE UPPER FLOW WILL BACK TO NORTHWEST AS AN UPPER
SHORTWAVE STARTS DIGGING SOUTH ALONG THE COAST OF BRITISH COLUMBIA.
THAT SYSTEM WILL MOVE ACROSS THE FORECAST AREA SUNDAY NIGHT AND
MONDAY...PROBABLY BRINGING AREAS OF LIGHT PRECIPITATION TO WESTERN
WASHINGTON. THE SNOW LEVEL WILL BE AROUND 2000 TO 3000 FT. DRY
NORTHERLY FLOW WILL RESUME TUESDAY AND WEDNESDAY. OF COURSE THERE
ARE SOME DIFFERENCES IN THE LONGER RANGE MODELS...BUT THEY ALL
INDICATE THIS SAME BASIC PATTERN.   MCDONNAL

&&

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

&&

.AVIATION...AN UPPER TROUGH WILL DEVELOP OVER THE WEST COAST OF
NORTH AMERICA THROUGH FRIDAY. SURFACE LOW PRESSURE WILL SHIFT FROM
THE B.C. COASTAL WATERS TODAY TO THE WA COAST TONIGHT. THE LOW
PRESSURE AREA WILL CONTINUE SOUTH INTO THE GREAT BASIN BY THE
WEEKEND AS HIGH PRESSURE BUILDS OVER BRITISH COLUMBIA. MOIST AIR AND
SHOWERS THROUGH TONIGHT WILL GIVE WAY TO NORTHERLY FLOW AND CLEARING
BY FRIDAY NIGHT.

KSEA...SHOWERY CLOUDY WEATHER WILL CONTINUE THROUGH TONIGHT AND THEN
NORTHERLY WINDS AND CLEARING WILL DEVELOP STARTING AROUND FRIDAY
AFTERNOON.

&&

.MARINE...A WEAK FRONTAL SYSTEM WILL STALL AS IT MOVES ONTO THE
COAST THIS EVENING. THEN A DIFFUSE AND BROAD 1008 MB LOW WILL DROP
SSE FROM THE QUEEN CHARLOTTE SOUND INTO THE COASTAL WATERS TONIGHT.
PRESSURE GRADIENTS ARE EXPECTED TO REMAIN LIGHT OVER THE WATERS
THROUGH EARLY FRI. HIGH PRES WILL BUILD OVER THE INTERIOR OF BRITISH
COLUMBIA FRIDAY. AS THE LOW LATE TONIGHT PASSES SOUTH OF THE AREA
EXPECT N TO NE FLOW TO INCREASE. SMALL CRAFT ADVISORY CONDITIONS ARE
LIKELY OVER MOST OF THE WATERS LATER FRI OR FRI NIGHT INTO SAT. HIGH
PRES WILL MOVE INTO THE WATERS SUNDAY GIVING LIGHT WINDS. ANOTHER
LOW WILL DROP SOUTHEAST ACROSS THE AREA SUN NIGHT AND MONDAY...AGAIN
FOLLOWED BY NE WINDS AS HIGH PRESSURE BUILDS OVER B.C.

&&

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

&&

$$

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






000
FXUS66 KSEW 261647
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
845 AM PST THU FEB 26 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL PRODUCE SCATTERED SHOWERS
ACROSS WESTERN WASHINGTON TODAY THROUGH FRIDAY...ESPECIALLY AT THE
COAST AND IN THE SOUTHWEST. A FEW INCHES OF SNOW WILL FALL IN THE
MOUNTAINS. AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS THIS WEEKEND. A WEAK SYSTEM WILL MOVE THROUGH SUNDAY
NIGHT AND MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...THE PREDOMINANT WEATHER AROUND WESTERN WASHINGTON THIS
MORNING APPEARS TO BE FOG...OR AT LEAST MIST...WHICH APPEARS IN MANY
OBSERVATIONS. THERE IS ALSO SOME DRIZZLE. MODELS STILL SHOW SOME
ENHANCEMENT OF SHOWERS THIS AFTERNOON AS AN UPPER LEVEL LOW
APPROACHES FROM THE NORTHWEST. THERE APPEAR TO BE SEVERAL CLOUD
LAYERS UP TO 10K FEET. HIGHS TODAY WILL BE IN THE LOW 50S.

THE UPPER LEVEL LOW WILL MOVE SOUTH ALONG THE COAST TONIGHT AND INTO
OREGON FRIDAY. THERE WILL BE SHOWERS ASSOCIATED WITH THIS LOW...WITH
THE MOST SHOWERS ON THE COAST AND OVER THE SOUTHWEST. STARTING
FRIDAY NIGHT COLDER SURFACE AIR WILL MOVE SOUTH OUT OF BRITISH
COLUMBIA INTO WASHINGTON. THIS WILL CLEAR THE SHOWERS AND CLOUDS OUT
OF THE AREA FROM NORTH TO SOUTH. SATURDAY WILL BE CLEAR AND COOL.
HIGHS ON FRIDAY WILL BE IN THE LOW 50S AND WILL DIP TO AROUND 50 ON
SATURDAY. TEMPERATURES COULD FALL BELOW FREEZING SATURDAY NIGHT IN
WIND SHELTERED SPOTS. BURKE

.LONG TERM...PREVIOUS DISCUSSION...SUNDAY SHOULD BE ANOTHER DRY AND
SUNNY DAY...BUT THE UPPER FLOW WILL BACK TO NORTHWEST AS AN UPPER
SHORTWAVE STARTS DIGGING SOUTH ALONG THE COAST OF BRITISH COLUMBIA.
THAT SYSTEM WILL MOVE ACROSS THE FORECAST AREA SUNDAY NIGHT AND
MONDAY...PROBABLY BRINGING AREAS OF LIGHT PRECIPITATION TO WESTERN
WASHINGTON. THE SNOW LEVEL WILL BE AROUND 2000 TO 3000 FT. DRY
NORTHERLY FLOW WILL RESUME TUESDAY AND WEDNESDAY. OF COURSE THERE
ARE SOME DIFFERENCES IN THE LONGER RANGE MODELS...BUT THEY ALL
INDICATE THIS SAME BASIC PATTERN.   MCDONNAL

&&

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

&&

.AVIATION...AN UPPER TROUGH WILL DEVELOP OVER THE WEST COAST OF
NORTH AMERICA THROUGH FRIDAY. SURFACE LOW PRESSURE WILL SHIFT FROM
THE B.C. COASTAL WATERS TODAY TO THE WA COAST TONIGHT. THE LOW
PRESSURE AREA WILL CONTINUE SOUTH INTO THE GREAT BASIN BY THE
WEEKEND AS HIGH PRESSURE BUILDS OVER BRITISH COLUMBIA. MOIST AIR AND
SHOWERS THROUGH TONIGHT WILL GIVE WAY TO NORTHERLY FLOW AND CLEARING
BY FRIDAY NIGHT.

KSEA...SHOWERY CLOUDY WEATHER WILL CONTINUE THROUGH TONIGHT AND THEN
NORTHERLY WINDS AND CLEARING WILL DEVELOP STARTING AROUND FRIDAY
AFTERNOON.

&&

.MARINE...A WEAK FRONTAL SYSTEM WILL STALL AS IT MOVES ONTO THE
COAST THIS EVENING. THEN A DIFFUSE AND BROAD 1008 MB LOW WILL DROP
SSE FROM THE QUEEN CHARLOTTE SOUND INTO THE COASTAL WATERS TONIGHT.
PRESSURE GRADIENTS ARE EXPECTED TO REMAIN LIGHT OVER THE WATERS
THROUGH EARLY FRI. HIGH PRES WILL BUILD OVER THE INTERIOR OF BRITISH
COLUMBIA FRIDAY. AS THE LOW LATE TONIGHT PASSES SOUTH OF THE AREA
EXPECT N TO NE FLOW TO INCREASE. SMALL CRAFT ADVISORY CONDITIONS ARE
LIKELY OVER MOST OF THE WATERS LATER FRI OR FRI NIGHT INTO SAT. HIGH
PRES WILL MOVE INTO THE WATERS SUNDAY GIVING LIGHT WINDS. ANOTHER
LOW WILL DROP SOUTHEAST ACROSS THE AREA SUN NIGHT AND MONDAY...AGAIN
FOLLOWED BY NE WINDS AS HIGH PRESSURE BUILDS OVER B.C.

&&

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

&&

$$

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







000
FXUS66 KSEW 261104
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 AM PST THU FEB 26 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL PRODUCE SCATTERED SHOWERS
ACROSS WESTERN WASHINGTON TODAY THROUGH FRIDAY...ESPECIALLY AT THE
COAST AND IN THE SOUTHWEST. A FEW INCHES OF SNOW WILL FALL IN THE
MOUNTAINS. AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS THIS WEEKEND. A WEAK SYSTEM WILL MOVE THROUGH SUNDAY
NIGHT AND MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...NORTHWEST FLOW ALOFT CONTINUES OVER WESTERN WASHINGTON
AHEAD OF A LARGE UPPER RIDGE CENTERED WELL OFFSHORE ALONG 140W. A
WEAK UPPER SHORTWAVE IS JUST OFFSHORE -- INSIDE OF 130W -- AND
MOVING TOWARD THE FORECAST AREA IN THE NORTHWEST FLOW. THE AIR MASS
IS MOIST FROM THE SURFACE TO AROUND 10000 FT...WITH LIGHT SPOTTY
PRECIPITATION AND PATCHY FOG. TEMPERATURES AT 2 AM WERE IN THE 40S.

THE SHORTWAVE OFFSHORE WILL MOVE SOUTHEAST INTO THE PACIFIC
NORTHWEST TODAY...WITH THE CORE OF THE SYSTEM MOVING ACROSS WESTERN
OREGON THIS AFTERNOON. THERE WILL BE SHOWERS ACROSS OUR FORECAST
AREA MAINLY AT THE COAST...IN THE MOUNTAINS...AND ACROSS THE
SOUTHWEST INTERIOR. THE PUGET SOUND REGION AND NORTHWEST INTERIOR
SHOULD HAVE RELATIVELY LITTLE PRECIPITATION TODAY...AND PARTS OF
THOSE REGIONS COULD REMAIN DRY.

AN UPPER LOW CURRENTLY JUST NORTHWEST OF HAIDA GWAII WILL DEEPEN
SOMEWHAT AS IT DIGS SOUTHEAST TODAY...MOVING TO A POSITION NEAR THE
WASHINGTON COAST LATE TONIGHT. IT WILL BRING MORE WIDESPREAD
SHOWERS...WITH POSSIBLY UP TO AN INCH OF PRECIPITATION AND
THUNDERSTORMS IN THE VICINITY OF THE UPPER LOW.

THE UPPER LOW WILL CONTINUE SOUTHEAST INTO SOUTH CENTRAL OREGON ON
FRIDAY...WITH THE FLOW ALOFT OVER WESTERN WASHINGTON VEERING TO
NORTHERLY FRIDAY AND FRIDAY NIGHT. IN ADDITION...NORTHERLY OFFSHORE
FLOW WILL DEVELOP AT THE SURFACE LATE FRIDAY AND FRIDAY NIGHT AS
SURFACE HIGH PRESSURE MOVES SOUTH ACROSS BRITISH COLUMBIA. SHOWERS
SHOULD DECREASE FROM NORTH TO SOUTH AS THE AIR MASS OVER WESTERN
WASHINGTON DRIES LATE FRIDAY AND FRIDAY NIGHT. THERE WILL ALSO BE
SOME BREEZY NORTH OR NORTHEAST WINDS...ESPECIALLY IN THE NORTH
INTERIOR DUE TO FRASER RIVER OUTFLOW.

THE SNOW LEVEL WILL BE IN THE 3000 TO 4000 FT RANGE AS MOST OF THIS
PRECIPITATION OCCURS. THE OLYMPICS AND THE MOUNT RAINIER AREA SHOULD
GET THE HEAVIEST AMOUNTS...WITH UP TO AN INCH OF PRECIPITATION IN
SPOTS. THE CENTRAL AND NORTH CASCADES WILL PROBABLY RECEIVE 0.25 TO
0.75 INCH PRECIPITATION DURING THE PERIOD.

SATURDAY AND SATURDAY NIGHT SHOULD BE CLEAR WITH DRY NORTHEAST FLOW.
LOW LEVEL OFFSHORE FLOW WILL EASE...WHICH WILL ALLOW TEMPERATURES TO
FALL BELOW FREEZING SATURDAY NIGHT IN THE WIND SHELTERED SPOTS.
MCDONNAL

.LONG TERM...SUNDAY SHOULD BE ANOTHER DRY AND SUNNY DAY...BUT THE
UPPER FLOW WILL BACK TO NORTHWEST AS AN UPPER SHORTWAVE STARTS
DIGGING SOUTH ALONG THE COAST OF BRITISH COLUMBIA. THAT SYSTEM WILL
MOVE ACROSS THE FORECAST AREA SUNDAY NIGHT AND MONDAY...PROBABLY
BRINGING AREAS OF LIGHT PRECIPITATION TO WESTERN WASHINGTON. THE
SNOW LEVEL WILL BE AROUND 2000 TO 3000 FT. DRY NORTHERLY FLOW WILL
RESUME TUESDAY AND WEDNESDAY. OF COURSE THERE ARE SOME DIFFERENCES
IN THE LONGER RANGE MODELS...BUT THEY ALL INDICATE THIS SAME BASIC
PATTERN.   MCDONNAL

&&

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

&&

.AVIATION...NORTHWEST FLOW ALOFT EARLY THIS MORNING WILL BECOME
WESTERLY TODAY...THEN BRIEFLY SOUTHERLY TONIGHT AS AN UPPER LEVEL
LOW WEST OF HAIDA GWAII DROPS SOUTH INTO THE COASTAL WATERS. THE
FLOW ALOFT WILL BECOME NORTHEASTERLY LATE TONIGHT INTO EARLY FRIDAY
AS THE LOW DROPS TO THE SOUTH OF THE AREA. THE AIR MASS IS MOIST AND
STABLE. THE AIR MASS WILL DESTABILIZE SOMEWHAT OVER THE COASTAL
WATERS TONIGHT AS THE UPPER LOW TO THE NORTHWEST DROPS SOUTHWARD.

THIS MORNING...LIGHT NW FLOW ALOFT IS INTERACTING WITH THE VANCOUVER
ISLAND MOUNTAINS AND THE OLYMPICS...PRODUCING BROAD AND WEAK
CONVERGENCE BANDS OVER THE INTERIOR. ONE AREA OF CONVERGENCE
IS SEEN FROM THE SAN JUAN ISLANDS AND BELLINGHAM DOWN TO WHIDBEY
ISLAND NAS AND EVERETT WHILE ANOTHER IS SEEN FROM THE KITSAP
PENINSULA SE TO KSEA THEN ESE TO KSMP. CONDITIONS ARE GENERALLY MVFR
EXCEPT IN THE CONVERGENCE ZONE AREAS WHERE THEY ARE IFR. 06Z NAM12
BUFR SOUNDINGS SHOW ABUNDANT MOISTURE CONTINUING AROUND THE AREA
TODAY. THE PREFERRED HRRR SOLUTIONS SHOW SOME SLOW AND GRADUAL
IMPROVEMENT TO MAINLY MVFR CEILINGS EARLY THIS AFTERNOON.

AFTER ABOUT 22Z...A WEAKENING FRONT WELL OFFSHORE WILL STALL AS IT
MOVES ONTO THE OLYMPIC PENINSULA. THEN LOW PRESSURE OVER HAIDA GWAII
WILL DROP SOUTHWARD DOWN THE WASHINGTON COASTAL WATERS TONIGHT. THE
INTERIOR LOWLANDS WILL LIKELY STAY MVFR TONIGHT AS LOW LEVEL
FLOW BECOMES WEAKLY OFFSHORE. PRECIPITATION WITH THE LOW WILL KEEP
CONDITIONS ALONG THE COAST MAINLY IFR LATE THIS AFTERNOON THROUGH
THIS EVENING. ALBRECHT

KSEA...A CONVERGENCE ZONE NEAR THE TERMINAL WILL KEEP CONDITIONS
P6SM SCT005 OVC015-020 THIS MORNING WITH 3-5SM -RA BR BKN005
POSSIBLE AT TIMES TIL 18Z. CONDITIONS WILL GRADUALLY IMPROVE TO P6SM
VCSH BKN025-030 OVC050 THIS AFTERNOON. IF THE LOW MOVING DOWN FROM
THE NW COMES CLOSER THAN ANTICIPATED TO THE TERMINAL LATE THIS
AFTERNOON THROUGH TONIGHT...PRECIPITATION MAY BE MORE PERSISTENT AND
IFR CONDITIONS PREVAIL TONIGHT. WINDS WILL BE VARIABLE TO 5 KT.
ALBRECHT

&&

.MARINE...A WEAK FRONTAL SYSTEM WILL STALL AS IT MOVES ONTO THE
COAST THIS EVENING. THEN A DIFFUSE AND BROAD 1008 MB LOW WILL DROP
SSE FROM THE QUEEN CHARLOTTE SOUND INTO THE COASTAL WATERS TONIGHT.
PRES GRADIENTS ARE EXPECTED TO REMAIN LIGHT OVER THE WATERS THROUGH
EARLY FRI.

HIGH PRES WILL BUILD OVER THE INTERIOR OF BRITISH COLUMBIA FRI. AS
THE LOW LATE TONIGHT PASSES SOUTH OF THE AREA...EXPECT N TO NE FLOW
TO INCREASE. SMALL CRAFT ADVISORY CONDITIONS ARE LIKELY OVER MOST OF
THE WATERS LATER FRI OR FRI NIGHT INTO SAT. THERE IS A SMALL CHANCE
THAT GALE FORCE WINDS WILL OCCUR AROUND THE WEST ENTRANCE TO THE
STRAIT OF JUAN DE FUCA AND OVER PORTIONS OF THE NORTHERN INLAND
WATERS FRI NIGHT.

HIGH PRES WILL MOVE INTO THE WATERS ON SUN GIVING ANOTHER PERIOD OF
LIGHT WINDS.

ANOTHER LOW WILL DROP SOUTHEAST ACROSS THE AREA SUN NIGHT INTO MON
AND WILL BE FOLLOWED BY STRONG N TO NE PRES GRADIENTS LATER MON OR
MON NIGHT. GLOBAL FORECAST MODELS SHOW OFFSHORE FLOW BEHIND THE
SECOND LOW ON MON OR MON NIGHT BEING STRONGER THAN THE OFFSHORE FLOW
FRI NIGHT INTO SAT...AND GALE CONDITIONS ARE POSSIBLE AROUND THE
WEST ENTRANCE TO THE STRAIT OF JUAN DE FUCA AND THE NORTHERN INLAND
WATERS. ALBRECHT

&&

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

&&

$$

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







000
FXUS66 KSEW 261104
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 AM PST THU FEB 26 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL PRODUCE SCATTERED SHOWERS
ACROSS WESTERN WASHINGTON TODAY THROUGH FRIDAY...ESPECIALLY AT THE
COAST AND IN THE SOUTHWEST. A FEW INCHES OF SNOW WILL FALL IN THE
MOUNTAINS. AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS THIS WEEKEND. A WEAK SYSTEM WILL MOVE THROUGH SUNDAY
NIGHT AND MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...NORTHWEST FLOW ALOFT CONTINUES OVER WESTERN WASHINGTON
AHEAD OF A LARGE UPPER RIDGE CENTERED WELL OFFSHORE ALONG 140W. A
WEAK UPPER SHORTWAVE IS JUST OFFSHORE -- INSIDE OF 130W -- AND
MOVING TOWARD THE FORECAST AREA IN THE NORTHWEST FLOW. THE AIR MASS
IS MOIST FROM THE SURFACE TO AROUND 10000 FT...WITH LIGHT SPOTTY
PRECIPITATION AND PATCHY FOG. TEMPERATURES AT 2 AM WERE IN THE 40S.

THE SHORTWAVE OFFSHORE WILL MOVE SOUTHEAST INTO THE PACIFIC
NORTHWEST TODAY...WITH THE CORE OF THE SYSTEM MOVING ACROSS WESTERN
OREGON THIS AFTERNOON. THERE WILL BE SHOWERS ACROSS OUR FORECAST
AREA MAINLY AT THE COAST...IN THE MOUNTAINS...AND ACROSS THE
SOUTHWEST INTERIOR. THE PUGET SOUND REGION AND NORTHWEST INTERIOR
SHOULD HAVE RELATIVELY LITTLE PRECIPITATION TODAY...AND PARTS OF
THOSE REGIONS COULD REMAIN DRY.

AN UPPER LOW CURRENTLY JUST NORTHWEST OF HAIDA GWAII WILL DEEPEN
SOMEWHAT AS IT DIGS SOUTHEAST TODAY...MOVING TO A POSITION NEAR THE
WASHINGTON COAST LATE TONIGHT. IT WILL BRING MORE WIDESPREAD
SHOWERS...WITH POSSIBLY UP TO AN INCH OF PRECIPITATION AND
THUNDERSTORMS IN THE VICINITY OF THE UPPER LOW.

THE UPPER LOW WILL CONTINUE SOUTHEAST INTO SOUTH CENTRAL OREGON ON
FRIDAY...WITH THE FLOW ALOFT OVER WESTERN WASHINGTON VEERING TO
NORTHERLY FRIDAY AND FRIDAY NIGHT. IN ADDITION...NORTHERLY OFFSHORE
FLOW WILL DEVELOP AT THE SURFACE LATE FRIDAY AND FRIDAY NIGHT AS
SURFACE HIGH PRESSURE MOVES SOUTH ACROSS BRITISH COLUMBIA. SHOWERS
SHOULD DECREASE FROM NORTH TO SOUTH AS THE AIR MASS OVER WESTERN
WASHINGTON DRIES LATE FRIDAY AND FRIDAY NIGHT. THERE WILL ALSO BE
SOME BREEZY NORTH OR NORTHEAST WINDS...ESPECIALLY IN THE NORTH
INTERIOR DUE TO FRASER RIVER OUTFLOW.

THE SNOW LEVEL WILL BE IN THE 3000 TO 4000 FT RANGE AS MOST OF THIS
PRECIPITATION OCCURS. THE OLYMPICS AND THE MOUNT RAINIER AREA SHOULD
GET THE HEAVIEST AMOUNTS...WITH UP TO AN INCH OF PRECIPITATION IN
SPOTS. THE CENTRAL AND NORTH CASCADES WILL PROBABLY RECEIVE 0.25 TO
0.75 INCH PRECIPITATION DURING THE PERIOD.

SATURDAY AND SATURDAY NIGHT SHOULD BE CLEAR WITH DRY NORTHEAST FLOW.
LOW LEVEL OFFSHORE FLOW WILL EASE...WHICH WILL ALLOW TEMPERATURES TO
FALL BELOW FREEZING SATURDAY NIGHT IN THE WIND SHELTERED SPOTS.
MCDONNAL

.LONG TERM...SUNDAY SHOULD BE ANOTHER DRY AND SUNNY DAY...BUT THE
UPPER FLOW WILL BACK TO NORTHWEST AS AN UPPER SHORTWAVE STARTS
DIGGING SOUTH ALONG THE COAST OF BRITISH COLUMBIA. THAT SYSTEM WILL
MOVE ACROSS THE FORECAST AREA SUNDAY NIGHT AND MONDAY...PROBABLY
BRINGING AREAS OF LIGHT PRECIPITATION TO WESTERN WASHINGTON. THE
SNOW LEVEL WILL BE AROUND 2000 TO 3000 FT. DRY NORTHERLY FLOW WILL
RESUME TUESDAY AND WEDNESDAY. OF COURSE THERE ARE SOME DIFFERENCES
IN THE LONGER RANGE MODELS...BUT THEY ALL INDICATE THIS SAME BASIC
PATTERN.   MCDONNAL

&&

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

&&

.AVIATION...NORTHWEST FLOW ALOFT EARLY THIS MORNING WILL BECOME
WESTERLY TODAY...THEN BRIEFLY SOUTHERLY TONIGHT AS AN UPPER LEVEL
LOW WEST OF HAIDA GWAII DROPS SOUTH INTO THE COASTAL WATERS. THE
FLOW ALOFT WILL BECOME NORTHEASTERLY LATE TONIGHT INTO EARLY FRIDAY
AS THE LOW DROPS TO THE SOUTH OF THE AREA. THE AIR MASS IS MOIST AND
STABLE. THE AIR MASS WILL DESTABILIZE SOMEWHAT OVER THE COASTAL
WATERS TONIGHT AS THE UPPER LOW TO THE NORTHWEST DROPS SOUTHWARD.

THIS MORNING...LIGHT NW FLOW ALOFT IS INTERACTING WITH THE VANCOUVER
ISLAND MOUNTAINS AND THE OLYMPICS...PRODUCING BROAD AND WEAK
CONVERGENCE BANDS OVER THE INTERIOR. ONE AREA OF CONVERGENCE
IS SEEN FROM THE SAN JUAN ISLANDS AND BELLINGHAM DOWN TO WHIDBEY
ISLAND NAS AND EVERETT WHILE ANOTHER IS SEEN FROM THE KITSAP
PENINSULA SE TO KSEA THEN ESE TO KSMP. CONDITIONS ARE GENERALLY MVFR
EXCEPT IN THE CONVERGENCE ZONE AREAS WHERE THEY ARE IFR. 06Z NAM12
BUFR SOUNDINGS SHOW ABUNDANT MOISTURE CONTINUING AROUND THE AREA
TODAY. THE PREFERRED HRRR SOLUTIONS SHOW SOME SLOW AND GRADUAL
IMPROVEMENT TO MAINLY MVFR CEILINGS EARLY THIS AFTERNOON.

AFTER ABOUT 22Z...A WEAKENING FRONT WELL OFFSHORE WILL STALL AS IT
MOVES ONTO THE OLYMPIC PENINSULA. THEN LOW PRESSURE OVER HAIDA GWAII
WILL DROP SOUTHWARD DOWN THE WASHINGTON COASTAL WATERS TONIGHT. THE
INTERIOR LOWLANDS WILL LIKELY STAY MVFR TONIGHT AS LOW LEVEL
FLOW BECOMES WEAKLY OFFSHORE. PRECIPITATION WITH THE LOW WILL KEEP
CONDITIONS ALONG THE COAST MAINLY IFR LATE THIS AFTERNOON THROUGH
THIS EVENING. ALBRECHT

KSEA...A CONVERGENCE ZONE NEAR THE TERMINAL WILL KEEP CONDITIONS
P6SM SCT005 OVC015-020 THIS MORNING WITH 3-5SM -RA BR BKN005
POSSIBLE AT TIMES TIL 18Z. CONDITIONS WILL GRADUALLY IMPROVE TO P6SM
VCSH BKN025-030 OVC050 THIS AFTERNOON. IF THE LOW MOVING DOWN FROM
THE NW COMES CLOSER THAN ANTICIPATED TO THE TERMINAL LATE THIS
AFTERNOON THROUGH TONIGHT...PRECIPITATION MAY BE MORE PERSISTENT AND
IFR CONDITIONS PREVAIL TONIGHT. WINDS WILL BE VARIABLE TO 5 KT.
ALBRECHT

&&

.MARINE...A WEAK FRONTAL SYSTEM WILL STALL AS IT MOVES ONTO THE
COAST THIS EVENING. THEN A DIFFUSE AND BROAD 1008 MB LOW WILL DROP
SSE FROM THE QUEEN CHARLOTTE SOUND INTO THE COASTAL WATERS TONIGHT.
PRES GRADIENTS ARE EXPECTED TO REMAIN LIGHT OVER THE WATERS THROUGH
EARLY FRI.

HIGH PRES WILL BUILD OVER THE INTERIOR OF BRITISH COLUMBIA FRI. AS
THE LOW LATE TONIGHT PASSES SOUTH OF THE AREA...EXPECT N TO NE FLOW
TO INCREASE. SMALL CRAFT ADVISORY CONDITIONS ARE LIKELY OVER MOST OF
THE WATERS LATER FRI OR FRI NIGHT INTO SAT. THERE IS A SMALL CHANCE
THAT GALE FORCE WINDS WILL OCCUR AROUND THE WEST ENTRANCE TO THE
STRAIT OF JUAN DE FUCA AND OVER PORTIONS OF THE NORTHERN INLAND
WATERS FRI NIGHT.

HIGH PRES WILL MOVE INTO THE WATERS ON SUN GIVING ANOTHER PERIOD OF
LIGHT WINDS.

ANOTHER LOW WILL DROP SOUTHEAST ACROSS THE AREA SUN NIGHT INTO MON
AND WILL BE FOLLOWED BY STRONG N TO NE PRES GRADIENTS LATER MON OR
MON NIGHT. GLOBAL FORECAST MODELS SHOW OFFSHORE FLOW BEHIND THE
SECOND LOW ON MON OR MON NIGHT BEING STRONGER THAN THE OFFSHORE FLOW
FRI NIGHT INTO SAT...AND GALE CONDITIONS ARE POSSIBLE AROUND THE
WEST ENTRANCE TO THE STRAIT OF JUAN DE FUCA AND THE NORTHERN INLAND
WATERS. ALBRECHT

&&

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

&&

$$

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








000
FXUS66 KSEW 261104
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
300 AM PST THU FEB 26 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL PRODUCE SCATTERED SHOWERS
ACROSS WESTERN WASHINGTON TODAY THROUGH FRIDAY...ESPECIALLY AT THE
COAST AND IN THE SOUTHWEST. A FEW INCHES OF SNOW WILL FALL IN THE
MOUNTAINS. AN UPPER RIDGE AND OFFSHORE FLOW WILL BRING SUNNY DAYS
AND COOL NIGHTS THIS WEEKEND. A WEAK SYSTEM WILL MOVE THROUGH SUNDAY
NIGHT AND MONDAY...WITH DRY WEATHER AGAIN TUESDAY AND WEDNESDAY.

&&

.SHORT TERM...NORTHWEST FLOW ALOFT CONTINUES OVER WESTERN WASHINGTON
AHEAD OF A LARGE UPPER RIDGE CENTERED WELL OFFSHORE ALONG 140W. A
WEAK UPPER SHORTWAVE IS JUST OFFSHORE -- INSIDE OF 130W -- AND
MOVING TOWARD THE FORECAST AREA IN THE NORTHWEST FLOW. THE AIR MASS
IS MOIST FROM THE SURFACE TO AROUND 10000 FT...WITH LIGHT SPOTTY
PRECIPITATION AND PATCHY FOG. TEMPERATURES AT 2 AM WERE IN THE 40S.

THE SHORTWAVE OFFSHORE WILL MOVE SOUTHEAST INTO THE PACIFIC
NORTHWEST TODAY...WITH THE CORE OF THE SYSTEM MOVING ACROSS WESTERN
OREGON THIS AFTERNOON. THERE WILL BE SHOWERS ACROSS OUR FORECAST
AREA MAINLY AT THE COAST...IN THE MOUNTAINS...AND ACROSS THE
SOUTHWEST INTERIOR. THE PUGET SOUND REGION AND NORTHWEST INTERIOR
SHOULD HAVE RELATIVELY LITTLE PRECIPITATION TODAY...AND PARTS OF
THOSE REGIONS COULD REMAIN DRY.

AN UPPER LOW CURRENTLY JUST NORTHWEST OF HAIDA GWAII WILL DEEPEN
SOMEWHAT AS IT DIGS SOUTHEAST TODAY...MOVING TO A POSITION NEAR THE
WASHINGTON COAST LATE TONIGHT. IT WILL BRING MORE WIDESPREAD
SHOWERS...WITH POSSIBLY UP TO AN INCH OF PRECIPITATION AND
THUNDERSTORMS IN THE VICINITY OF THE UPPER LOW.

THE UPPER LOW WILL CONTINUE SOUTHEAST INTO SOUTH CENTRAL OREGON ON
FRIDAY...WITH THE FLOW ALOFT OVER WESTERN WASHINGTON VEERING TO
NORTHERLY FRIDAY AND FRIDAY NIGHT. IN ADDITION...NORTHERLY OFFSHORE
FLOW WILL DEVELOP AT THE SURFACE LATE FRIDAY AND FRIDAY NIGHT AS
SURFACE HIGH PRESSURE MOVES SOUTH ACROSS BRITISH COLUMBIA. SHOWERS
SHOULD DECREASE FROM NORTH TO SOUTH AS THE AIR MASS OVER WESTERN
WASHINGTON DRIES LATE FRIDAY AND FRIDAY NIGHT. THERE WILL ALSO BE
SOME BREEZY NORTH OR NORTHEAST WINDS...ESPECIALLY IN THE NORTH
INTERIOR DUE TO FRASER RIVER OUTFLOW.

THE SNOW LEVEL WILL BE IN THE 3000 TO 4000 FT RANGE AS MOST OF THIS
PRECIPITATION OCCURS. THE OLYMPICS AND THE MOUNT RAINIER AREA SHOULD
GET THE HEAVIEST AMOUNTS...WITH UP TO AN INCH OF PRECIPITATION IN
SPOTS. THE CENTRAL AND NORTH CASCADES WILL PROBABLY RECEIVE 0.25 TO
0.75 INCH PRECIPITATION DURING THE PERIOD.

SATURDAY AND SATURDAY NIGHT SHOULD BE CLEAR WITH DRY NORTHEAST FLOW.
LOW LEVEL OFFSHORE FLOW WILL EASE...WHICH WILL ALLOW TEMPERATURES TO
FALL BELOW FREEZING SATURDAY NIGHT IN THE WIND SHELTERED SPOTS.
MCDONNAL

.LONG TERM...SUNDAY SHOULD BE ANOTHER DRY AND SUNNY DAY...BUT THE
UPPER FLOW WILL BACK TO NORTHWEST AS AN UPPER SHORTWAVE STARTS
DIGGING SOUTH ALONG THE COAST OF BRITISH COLUMBIA. THAT SYSTEM WILL
MOVE ACROSS THE FORECAST AREA SUNDAY NIGHT AND MONDAY...PROBABLY
BRINGING AREAS OF LIGHT PRECIPITATION TO WESTERN WASHINGTON. THE
SNOW LEVEL WILL BE AROUND 2000 TO 3000 FT. DRY NORTHERLY FLOW WILL
RESUME TUESDAY AND WEDNESDAY. OF COURSE THERE ARE SOME DIFFERENCES
IN THE LONGER RANGE MODELS...BUT THEY ALL INDICATE THIS SAME BASIC
PATTERN.   MCDONNAL

&&

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

&&

.AVIATION...NORTHWEST FLOW ALOFT EARLY THIS MORNING WILL BECOME
WESTERLY TODAY...THEN BRIEFLY SOUTHERLY TONIGHT AS AN UPPER LEVEL
LOW WEST OF HAIDA GWAII DROPS SOUTH INTO THE COASTAL WATERS. THE
FLOW ALOFT WILL BECOME NORTHEASTERLY LATE TONIGHT INTO EARLY FRIDAY
AS THE LOW DROPS TO THE SOUTH OF THE AREA. THE AIR MASS IS MOIST AND
STABLE. THE AIR MASS WILL DESTABILIZE SOMEWHAT OVER THE COASTAL
WATERS TONIGHT AS THE UPPER LOW TO THE NORTHWEST DROPS SOUTHWARD.

THIS MORNING...LIGHT NW FLOW ALOFT IS INTERACTING WITH THE VANCOUVER
ISLAND MOUNTAINS AND THE OLYMPICS...PRODUCING BROAD AND WEAK
CONVERGENCE BANDS OVER THE INTERIOR. ONE AREA OF CONVERGENCE
IS SEEN FROM THE SAN JUAN ISLANDS AND BELLINGHAM DOWN TO WHIDBEY
ISLAND NAS AND EVERETT WHILE ANOTHER IS SEEN FROM THE KITSAP
PENINSULA SE TO KSEA THEN ESE TO KSMP. CONDITIONS ARE GENERALLY MVFR
EXCEPT IN THE CONVERGENCE ZONE AREAS WHERE THEY ARE IFR. 06Z NAM12
BUFR SOUNDINGS SHOW ABUNDANT MOISTURE CONTINUING AROUND THE AREA
TODAY. THE PREFERRED HRRR SOLUTIONS SHOW SOME SLOW AND GRADUAL
IMPROVEMENT TO MAINLY MVFR CEILINGS EARLY THIS AFTERNOON.

AFTER ABOUT 22Z...A WEAKENING FRONT WELL OFFSHORE WILL STALL AS IT
MOVES ONTO THE OLYMPIC PENINSULA. THEN LOW PRESSURE OVER HAIDA GWAII
WILL DROP SOUTHWARD DOWN THE WASHINGTON COASTAL WATERS TONIGHT. THE
INTERIOR LOWLANDS WILL LIKELY STAY MVFR TONIGHT AS LOW LEVEL
FLOW BECOMES WEAKLY OFFSHORE. PRECIPITATION WITH THE LOW WILL KEEP
CONDITIONS ALONG THE COAST MAINLY IFR LATE THIS AFTERNOON THROUGH
THIS EVENING. ALBRECHT

KSEA...A CONVERGENCE ZONE NEAR THE TERMINAL WILL KEEP CONDITIONS
P6SM SCT005 OVC015-020 THIS MORNING WITH 3-5SM -RA BR BKN005
POSSIBLE AT TIMES TIL 18Z. CONDITIONS WILL GRADUALLY IMPROVE TO P6SM
VCSH BKN025-030 OVC050 THIS AFTERNOON. IF THE LOW MOVING DOWN FROM
THE NW COMES CLOSER THAN ANTICIPATED TO THE TERMINAL LATE THIS
AFTERNOON THROUGH TONIGHT...PRECIPITATION MAY BE MORE PERSISTENT AND
IFR CONDITIONS PREVAIL TONIGHT. WINDS WILL BE VARIABLE TO 5 KT.
ALBRECHT

&&

.MARINE...A WEAK FRONTAL SYSTEM WILL STALL AS IT MOVES ONTO THE
COAST THIS EVENING. THEN A DIFFUSE AND BROAD 1008 MB LOW WILL DROP
SSE FROM THE QUEEN CHARLOTTE SOUND INTO THE COASTAL WATERS TONIGHT.
PRES GRADIENTS ARE EXPECTED TO REMAIN LIGHT OVER THE WATERS THROUGH
EARLY FRI.

HIGH PRES WILL BUILD OVER THE INTERIOR OF BRITISH COLUMBIA FRI. AS
THE LOW LATE TONIGHT PASSES SOUTH OF THE AREA...EXPECT N TO NE FLOW
TO INCREASE. SMALL CRAFT ADVISORY CONDITIONS ARE LIKELY OVER MOST OF
THE WATERS LATER FRI OR FRI NIGHT INTO SAT. THERE IS A SMALL CHANCE
THAT GALE FORCE WINDS WILL OCCUR AROUND THE WEST ENTRANCE TO THE
STRAIT OF JUAN DE FUCA AND OVER PORTIONS OF THE NORTHERN INLAND
WATERS FRI NIGHT.

HIGH PRES WILL MOVE INTO THE WATERS ON SUN GIVING ANOTHER PERIOD OF
LIGHT WINDS.

ANOTHER LOW WILL DROP SOUTHEAST ACROSS THE AREA SUN NIGHT INTO MON
AND WILL BE FOLLOWED BY STRONG N TO NE PRES GRADIENTS LATER MON OR
MON NIGHT. GLOBAL FORECAST MODELS SHOW OFFSHORE FLOW BEHIND THE
SECOND LOW ON MON OR MON NIGHT BEING STRONGER THAN THE OFFSHORE FLOW
FRI NIGHT INTO SAT...AND GALE CONDITIONS ARE POSSIBLE AROUND THE
WEST ENTRANCE TO THE STRAIT OF JUAN DE FUCA AND THE NORTHERN INLAND
WATERS. ALBRECHT

&&

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

&&

$$

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







000
FXUS66 KSEW 260434
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PST WED FEB 25 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL BRING RAIN AT TIMES TO
WESTERN WASHINGTON TONIGHT. RAIN WILL TRANSITION TO SHOWERS ON
THURSDAY AND PERSIST THROUGH FRIDAY. OFFSHORE FLOW AND AN UPPER
RIDGE WILL GIVE DRY WEATHER SATURDAY AND SUNDAY. A WETTER AND COOLER
PATTERN WILL RETURN EARLY NEXT WEEK.

&&

.SHORT TERM...LATEST RADAR AND OBS SHOW AREAS OF LIGHT RAIN ACROSS
WRN WA THIS EVENING. PRECIPITATION AMOUNTS SO FAR HAVE GENERALLY
BEEN UNDER ONE TENTH SINCE THIS MORNING...EXCEPT LOCALLY HIGHER
ALONG THE N COAST. SPOTTY LIGHT RAIN WILL CONTINUE THROUGH TONIGHT
AS A WEAK SURFACE TROUGH OFFSHORE DIGS SE OVER WRN WA/OREGON. SOME
WEAK CONVERGENCE IS OCCURRING AROUND THE CENTRAL PUGET SOUND
REGION...ESPECIALLY WRN KING COUNTY. THE HRRR SHOWS THIS CONTINUING
THROUGH LATE TONIGHT BEFORE DISSIPATING SO EXPECT STEADIER RAIN
AROUND SEATTLE.

MOIST NW FLOW ALOFT CONTINUES INTO THURSDAY AS A COOL UPPER TROUGH
OFF THE CENTRAL B.C. COAST BEGINS TO DIG SE TOWARD THE AREA. RAIN
WILL TRANSITION TO A MORE SHOWERY REGIME AS THE TROUGH APPROACHES
AND COOLER AIR ALOFT ARRIVES. MODELS SHOW A 500 MB -28C COLD POCKET
OVER THE REGION BY THURSDAY NIGHT SO THE ATMOSPHERE WILL BE
MARGINALLY UNSTABLE. THE CHANCE OF THUNDERSTORMS IN THE FORECAST FOR
THE COAST IS A BIT IFFY BUT WITH THE LOW OVERHEAD IT CANNOT BE RULED
OUT EITHER. WILL NOT MAKE ANY CHANGES.

SHOWERS DECREASE ON FRIDAY AS THE STACKED UPPER/SURFACE LOW SHIFT
SWD INTO OREGON. NLY FLOW WILL DEVELOP AND A 1035 MB SURFACE HIGH
WILL SETTLE INTO SRN B.C. SO EXPECT BREEZY NLY OUTFLOW WINDS TO PICK
UP. BY FRIDAY NIGHT...CLEARING SKIES ARE EXPECTED WITH COOLER
TEMPERATURES. BREEZY WINDS WILL HELP KEEP MOST PLACES JUST ABOVE
FREEZING. HOWEVER...SHELTERED LOCATIONS LIKE OLYMPIA WILL HAVE
TEMPERATURES CLOSER TO OR JUST BELOW THE FREEZING MARK SATURDAY
MORNING. LOW TEMPERATURES IN THE COLD POCKETS WILL NEED SOME
DOWNWARD ADJUSTMENT WITH THE NEXT FORECAST ISSUANCE. WITH HIGH
PRESSURE BUILDING ALOFT...CLEAR SKIES WILL PREVAIL ON SATURDAY WITH
HIGHS STRUGGLING TO REACH ABOVE 50.  MERCER

.LONG TERM...FROM PREVIOUS DISCUSSION...SUNDAY WILL BE MOSTLY SUNNY
AND TEMPERATURES WILL REBOUND A BIT. THE GFS AND EURO BOTH HAVE A
WEAK SYSTEM MOVING ALMOST DUE SOUTH ALONG THE COAST SUNDAY NIGHT AND
MONDAY. CHANCE POPS COVER THIS SYSTEM FOR NOW. AFTER IT PASSES
NORTHERLY AND OFFSHORE FLOW WILL AGAIN DEVELOP WITH MONDAY NIGHT AND
TUESDAY LOOKING BREEZY AND COOL. DRY WEATHER CONTINUES THROUGH
WEDNESDAY. HIGH TEMPERATURES ON TUESDAY AND WEDNESDAY WILL BE MOSTLY
IN THE 40S WITH LOWS IN THE 30S. BURKE

&&

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

&&

.AVIATION...NORTHWEST FLOW ALOFT. WEAK DISTURBANCES WILL MOVE SE
ACROSS THE AREA TONIGHT THROUGH THU. THEN A BROAD AND DIFFUSE 1008
MB LOW WILL MOVE SWD THROUGH THE COASTAL WATERS LATE THU NIGHT. THE
AIR MASS IS STABLE AND MOIST.

WHILE VFR CIGS AND VSBYS ARE MOST COMMON ACROSS THE AREA THIS
EVENING...CONDITIONS ARE MIXED. AN AREA OF SHOWERS ALONG THE COAST
IS GIVING LOCAL IFR CIGS AND VSBYS TO THE NORTH COAST. AN AREA OF
CONVERGENCE TO THE LEE OF THE MOUNTAINS OF VANCOUVER ISLAND IS
GIVING MVFR CIGS TO THE NORTHERN INTERIOR OF W WA FROM THE SAN JUAN
ISLANDS AND THE KBLI AREA SE INTO NORTHERN SNOHOMISH COUNTY. ANOTHER
NARROWER CONVERGENCE ZONE EXTENDS FROM E OF KSEA TO KSMP. BETWEEN
THE AREAS OF CONVERGENCE...CONDITIONS ARE VFR WITH CIGS AROUND
FL045. VIS IS OCNLY DROPPING TO 2-4 SM BR BETWEEN SHOWERS IN A FEW
SPOTS. THE LATEST HRRR SOLUTIONS SHOW ABUNDANT MVFR CIGS
DEVELOPING THIS EVENING WITH AREAS OF IFR CIGS AROUND THE AREA
THROUGH THU MORNING. IT APPEARS THAT THERE WILL BE LITTLE SKILL
IN PINPOINTING WHERE THE LOWER CLOUDS WILL DEVELOP OR MOVE WITH THE
LIGHT FLOW AND DRIPS OF PRECIPITATION.

ANOTHER WEAK FRONTAL LIKE FEATURE CAN BE SEEN EXTENDING SE FROM 50N
145W. THIS FEATURE WILL MOST LIKELY STALL ALONG THE COAST THU
AFTERNOON AND EVENING AS LOW PRES MOVING INTO THE QUEEN CHARLOTTE
SOUND MIDDAY THU DROPS SSE INTO THE COASTAL WATERS THU NIGHT. THIS
WEAK FEATURE WILL HELP TO FOCUS PRECIPITATION OVER THE OLYMPIC
PENINSULA RESULTING IN MVFR TO LOCAL IFR CONDITIONS THERE. THE
INTERIOR MAY FARE SLIGHTLY BETTER...VFR WITH OCCASIONAL MVFR CIGS
AND VIS AS FLOW BECOMES WEAKLY OFFSHORE. ALBRECHT

KSEA...CONDITIONS WILL AVERAGE P6SM BKN015 OVC040 THROUGH THU
MORNING. LOW LEVEL CONVERGENCE CENTERED NEAR THE TERMINAL WILL
GIVE LIGHT WINDS. ALBRECHT

&&

.MARINE...WEAK FRONTAL FEATURES MOVING SE THROUGH THE WATERS WILL
DISSIPATE AS THEY MOVE TO THE COASTLINE TONIGHT THROUGH THU. EXPECT
LIGHT PRES GRADIENTS ACROSS THE WATERS. A DIFFUSE AND BROAD 1008 MB
LOW WILL DROP SSE FROM THE QUEEN CHARLOTTE SOUND MIDDAY THU THROUGH
THE COASTAL WATERS LATE THU NIGHT. LIGHT FLOW WILL DOMINATE AS THE
LOW PASSES...THEN WINDS WILL TURN NELY AS THE LOW MOVES S INTO
WESTERN OREGON.

HIGH PRES WILL BUILD OVER THE INTERIOR OF BRITISH COLUMBIA FRI. AS
THE LOW LATE THU NIGHT PASSES SOUTH OF THE AREA...EXPECT N TO NE
FLOW TO INCREASE. SMALL CRAFT ADVISORY CONDITIONS ARE LIKELY OVER
MOST OF THE WATERS FRI NIGHT INTO EARLY SAT. THERE IS A SMALL CHANCE
THAT GALE FORCE WINDS WILL OCCUR AROUND THE WEST ENTRANCE TO THE
STRAIT OF JUAN DE FUCA AND OVER PORTIONS OF THE NORTHERN INLAND
WATERS FRI NIGHT.

HIGH PRES WILL MOVE INTO THE WATERS ON SUN GIVING ANOTHER PERIOD OF
LIGHT WINDS.

ANOTHER LOW WILL DROP SOUTHEAST ACROSS THE AREA SUN NIGHT INTO MON
AND WILL BE FOLLOWED BY STRONG NE PRES GRADIENTS LATER MON OR MON
NIGHT. ALBRECHT

&&

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

&&

$$

WWW.WEATHER.GOV/SEATTLE/

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









000
FXUS66 KSEW 260434
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PST WED FEB 25 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL BRING RAIN AT TIMES TO
WESTERN WASHINGTON TONIGHT. RAIN WILL TRANSITION TO SHOWERS ON
THURSDAY AND PERSIST THROUGH FRIDAY. OFFSHORE FLOW AND AN UPPER
RIDGE WILL GIVE DRY WEATHER SATURDAY AND SUNDAY. A WETTER AND COOLER
PATTERN WILL RETURN EARLY NEXT WEEK.

&&

.SHORT TERM...LATEST RADAR AND OBS SHOW AREAS OF LIGHT RAIN ACROSS
WRN WA THIS EVENING. PRECIPITATION AMOUNTS SO FAR HAVE GENERALLY
BEEN UNDER ONE TENTH SINCE THIS MORNING...EXCEPT LOCALLY HIGHER
ALONG THE N COAST. SPOTTY LIGHT RAIN WILL CONTINUE THROUGH TONIGHT
AS A WEAK SURFACE TROUGH OFFSHORE DIGS SE OVER WRN WA/OREGON. SOME
WEAK CONVERGENCE IS OCCURRING AROUND THE CENTRAL PUGET SOUND
REGION...ESPECIALLY WRN KING COUNTY. THE HRRR SHOWS THIS CONTINUING
THROUGH LATE TONIGHT BEFORE DISSIPATING SO EXPECT STEADIER RAIN
AROUND SEATTLE.

MOIST NW FLOW ALOFT CONTINUES INTO THURSDAY AS A COOL UPPER TROUGH
OFF THE CENTRAL B.C. COAST BEGINS TO DIG SE TOWARD THE AREA. RAIN
WILL TRANSITION TO A MORE SHOWERY REGIME AS THE TROUGH APPROACHES
AND COOLER AIR ALOFT ARRIVES. MODELS SHOW A 500 MB -28C COLD POCKET
OVER THE REGION BY THURSDAY NIGHT SO THE ATMOSPHERE WILL BE
MARGINALLY UNSTABLE. THE CHANCE OF THUNDERSTORMS IN THE FORECAST FOR
THE COAST IS A BIT IFFY BUT WITH THE LOW OVERHEAD IT CANNOT BE RULED
OUT EITHER. WILL NOT MAKE ANY CHANGES.

SHOWERS DECREASE ON FRIDAY AS THE STACKED UPPER/SURFACE LOW SHIFT
SWD INTO OREGON. NLY FLOW WILL DEVELOP AND A 1035 MB SURFACE HIGH
WILL SETTLE INTO SRN B.C. SO EXPECT BREEZY NLY OUTFLOW WINDS TO PICK
UP. BY FRIDAY NIGHT...CLEARING SKIES ARE EXPECTED WITH COOLER
TEMPERATURES. BREEZY WINDS WILL HELP KEEP MOST PLACES JUST ABOVE
FREEZING. HOWEVER...SHELTERED LOCATIONS LIKE OLYMPIA WILL HAVE
TEMPERATURES CLOSER TO OR JUST BELOW THE FREEZING MARK SATURDAY
MORNING. LOW TEMPERATURES IN THE COLD POCKETS WILL NEED SOME
DOWNWARD ADJUSTMENT WITH THE NEXT FORECAST ISSUANCE. WITH HIGH
PRESSURE BUILDING ALOFT...CLEAR SKIES WILL PREVAIL ON SATURDAY WITH
HIGHS STRUGGLING TO REACH ABOVE 50.  MERCER

.LONG TERM...FROM PREVIOUS DISCUSSION...SUNDAY WILL BE MOSTLY SUNNY
AND TEMPERATURES WILL REBOUND A BIT. THE GFS AND EURO BOTH HAVE A
WEAK SYSTEM MOVING ALMOST DUE SOUTH ALONG THE COAST SUNDAY NIGHT AND
MONDAY. CHANCE POPS COVER THIS SYSTEM FOR NOW. AFTER IT PASSES
NORTHERLY AND OFFSHORE FLOW WILL AGAIN DEVELOP WITH MONDAY NIGHT AND
TUESDAY LOOKING BREEZY AND COOL. DRY WEATHER CONTINUES THROUGH
WEDNESDAY. HIGH TEMPERATURES ON TUESDAY AND WEDNESDAY WILL BE MOSTLY
IN THE 40S WITH LOWS IN THE 30S. BURKE

&&

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

&&

.AVIATION...NORTHWEST FLOW ALOFT. WEAK DISTURBANCES WILL MOVE SE
ACROSS THE AREA TONIGHT THROUGH THU. THEN A BROAD AND DIFFUSE 1008
MB LOW WILL MOVE SWD THROUGH THE COASTAL WATERS LATE THU NIGHT. THE
AIR MASS IS STABLE AND MOIST.

WHILE VFR CIGS AND VSBYS ARE MOST COMMON ACROSS THE AREA THIS
EVENING...CONDITIONS ARE MIXED. AN AREA OF SHOWERS ALONG THE COAST
IS GIVING LOCAL IFR CIGS AND VSBYS TO THE NORTH COAST. AN AREA OF
CONVERGENCE TO THE LEE OF THE MOUNTAINS OF VANCOUVER ISLAND IS
GIVING MVFR CIGS TO THE NORTHERN INTERIOR OF W WA FROM THE SAN JUAN
ISLANDS AND THE KBLI AREA SE INTO NORTHERN SNOHOMISH COUNTY. ANOTHER
NARROWER CONVERGENCE ZONE EXTENDS FROM E OF KSEA TO KSMP. BETWEEN
THE AREAS OF CONVERGENCE...CONDITIONS ARE VFR WITH CIGS AROUND
FL045. VIS IS OCNLY DROPPING TO 2-4 SM BR BETWEEN SHOWERS IN A FEW
SPOTS. THE LATEST HRRR SOLUTIONS SHOW ABUNDANT MVFR CIGS
DEVELOPING THIS EVENING WITH AREAS OF IFR CIGS AROUND THE AREA
THROUGH THU MORNING. IT APPEARS THAT THERE WILL BE LITTLE SKILL
IN PINPOINTING WHERE THE LOWER CLOUDS WILL DEVELOP OR MOVE WITH THE
LIGHT FLOW AND DRIPS OF PRECIPITATION.

ANOTHER WEAK FRONTAL LIKE FEATURE CAN BE SEEN EXTENDING SE FROM 50N
145W. THIS FEATURE WILL MOST LIKELY STALL ALONG THE COAST THU
AFTERNOON AND EVENING AS LOW PRES MOVING INTO THE QUEEN CHARLOTTE
SOUND MIDDAY THU DROPS SSE INTO THE COASTAL WATERS THU NIGHT. THIS
WEAK FEATURE WILL HELP TO FOCUS PRECIPITATION OVER THE OLYMPIC
PENINSULA RESULTING IN MVFR TO LOCAL IFR CONDITIONS THERE. THE
INTERIOR MAY FARE SLIGHTLY BETTER...VFR WITH OCCASIONAL MVFR CIGS
AND VIS AS FLOW BECOMES WEAKLY OFFSHORE. ALBRECHT

KSEA...CONDITIONS WILL AVERAGE P6SM BKN015 OVC040 THROUGH THU
MORNING. LOW LEVEL CONVERGENCE CENTERED NEAR THE TERMINAL WILL
GIVE LIGHT WINDS. ALBRECHT

&&

.MARINE...WEAK FRONTAL FEATURES MOVING SE THROUGH THE WATERS WILL
DISSIPATE AS THEY MOVE TO THE COASTLINE TONIGHT THROUGH THU. EXPECT
LIGHT PRES GRADIENTS ACROSS THE WATERS. A DIFFUSE AND BROAD 1008 MB
LOW WILL DROP SSE FROM THE QUEEN CHARLOTTE SOUND MIDDAY THU THROUGH
THE COASTAL WATERS LATE THU NIGHT. LIGHT FLOW WILL DOMINATE AS THE
LOW PASSES...THEN WINDS WILL TURN NELY AS THE LOW MOVES S INTO
WESTERN OREGON.

HIGH PRES WILL BUILD OVER THE INTERIOR OF BRITISH COLUMBIA FRI. AS
THE LOW LATE THU NIGHT PASSES SOUTH OF THE AREA...EXPECT N TO NE
FLOW TO INCREASE. SMALL CRAFT ADVISORY CONDITIONS ARE LIKELY OVER
MOST OF THE WATERS FRI NIGHT INTO EARLY SAT. THERE IS A SMALL CHANCE
THAT GALE FORCE WINDS WILL OCCUR AROUND THE WEST ENTRANCE TO THE
STRAIT OF JUAN DE FUCA AND OVER PORTIONS OF THE NORTHERN INLAND
WATERS FRI NIGHT.

HIGH PRES WILL MOVE INTO THE WATERS ON SUN GIVING ANOTHER PERIOD OF
LIGHT WINDS.

ANOTHER LOW WILL DROP SOUTHEAST ACROSS THE AREA SUN NIGHT INTO MON
AND WILL BE FOLLOWED BY STRONG NE PRES GRADIENTS LATER MON OR MON
NIGHT. ALBRECHT

&&

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

&&

$$

WWW.WEATHER.GOV/SEATTLE/

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










000
FXUS66 KSEW 260434
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PST WED FEB 25 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL BRING RAIN AT TIMES TO
WESTERN WASHINGTON TONIGHT. RAIN WILL TRANSITION TO SHOWERS ON
THURSDAY AND PERSIST THROUGH FRIDAY. OFFSHORE FLOW AND AN UPPER
RIDGE WILL GIVE DRY WEATHER SATURDAY AND SUNDAY. A WETTER AND COOLER
PATTERN WILL RETURN EARLY NEXT WEEK.

&&

.SHORT TERM...LATEST RADAR AND OBS SHOW AREAS OF LIGHT RAIN ACROSS
WRN WA THIS EVENING. PRECIPITATION AMOUNTS SO FAR HAVE GENERALLY
BEEN UNDER ONE TENTH SINCE THIS MORNING...EXCEPT LOCALLY HIGHER
ALONG THE N COAST. SPOTTY LIGHT RAIN WILL CONTINUE THROUGH TONIGHT
AS A WEAK SURFACE TROUGH OFFSHORE DIGS SE OVER WRN WA/OREGON. SOME
WEAK CONVERGENCE IS OCCURRING AROUND THE CENTRAL PUGET SOUND
REGION...ESPECIALLY WRN KING COUNTY. THE HRRR SHOWS THIS CONTINUING
THROUGH LATE TONIGHT BEFORE DISSIPATING SO EXPECT STEADIER RAIN
AROUND SEATTLE.

MOIST NW FLOW ALOFT CONTINUES INTO THURSDAY AS A COOL UPPER TROUGH
OFF THE CENTRAL B.C. COAST BEGINS TO DIG SE TOWARD THE AREA. RAIN
WILL TRANSITION TO A MORE SHOWERY REGIME AS THE TROUGH APPROACHES
AND COOLER AIR ALOFT ARRIVES. MODELS SHOW A 500 MB -28C COLD POCKET
OVER THE REGION BY THURSDAY NIGHT SO THE ATMOSPHERE WILL BE
MARGINALLY UNSTABLE. THE CHANCE OF THUNDERSTORMS IN THE FORECAST FOR
THE COAST IS A BIT IFFY BUT WITH THE LOW OVERHEAD IT CANNOT BE RULED
OUT EITHER. WILL NOT MAKE ANY CHANGES.

SHOWERS DECREASE ON FRIDAY AS THE STACKED UPPER/SURFACE LOW SHIFT
SWD INTO OREGON. NLY FLOW WILL DEVELOP AND A 1035 MB SURFACE HIGH
WILL SETTLE INTO SRN B.C. SO EXPECT BREEZY NLY OUTFLOW WINDS TO PICK
UP. BY FRIDAY NIGHT...CLEARING SKIES ARE EXPECTED WITH COOLER
TEMPERATURES. BREEZY WINDS WILL HELP KEEP MOST PLACES JUST ABOVE
FREEZING. HOWEVER...SHELTERED LOCATIONS LIKE OLYMPIA WILL HAVE
TEMPERATURES CLOSER TO OR JUST BELOW THE FREEZING MARK SATURDAY
MORNING. LOW TEMPERATURES IN THE COLD POCKETS WILL NEED SOME
DOWNWARD ADJUSTMENT WITH THE NEXT FORECAST ISSUANCE. WITH HIGH
PRESSURE BUILDING ALOFT...CLEAR SKIES WILL PREVAIL ON SATURDAY WITH
HIGHS STRUGGLING TO REACH ABOVE 50.  MERCER

.LONG TERM...FROM PREVIOUS DISCUSSION...SUNDAY WILL BE MOSTLY SUNNY
AND TEMPERATURES WILL REBOUND A BIT. THE GFS AND EURO BOTH HAVE A
WEAK SYSTEM MOVING ALMOST DUE SOUTH ALONG THE COAST SUNDAY NIGHT AND
MONDAY. CHANCE POPS COVER THIS SYSTEM FOR NOW. AFTER IT PASSES
NORTHERLY AND OFFSHORE FLOW WILL AGAIN DEVELOP WITH MONDAY NIGHT AND
TUESDAY LOOKING BREEZY AND COOL. DRY WEATHER CONTINUES THROUGH
WEDNESDAY. HIGH TEMPERATURES ON TUESDAY AND WEDNESDAY WILL BE MOSTLY
IN THE 40S WITH LOWS IN THE 30S. BURKE

&&

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

&&

.AVIATION...NORTHWEST FLOW ALOFT. WEAK DISTURBANCES WILL MOVE SE
ACROSS THE AREA TONIGHT THROUGH THU. THEN A BROAD AND DIFFUSE 1008
MB LOW WILL MOVE SWD THROUGH THE COASTAL WATERS LATE THU NIGHT. THE
AIR MASS IS STABLE AND MOIST.

WHILE VFR CIGS AND VSBYS ARE MOST COMMON ACROSS THE AREA THIS
EVENING...CONDITIONS ARE MIXED. AN AREA OF SHOWERS ALONG THE COAST
IS GIVING LOCAL IFR CIGS AND VSBYS TO THE NORTH COAST. AN AREA OF
CONVERGENCE TO THE LEE OF THE MOUNTAINS OF VANCOUVER ISLAND IS
GIVING MVFR CIGS TO THE NORTHERN INTERIOR OF W WA FROM THE SAN JUAN
ISLANDS AND THE KBLI AREA SE INTO NORTHERN SNOHOMISH COUNTY. ANOTHER
NARROWER CONVERGENCE ZONE EXTENDS FROM E OF KSEA TO KSMP. BETWEEN
THE AREAS OF CONVERGENCE...CONDITIONS ARE VFR WITH CIGS AROUND
FL045. VIS IS OCNLY DROPPING TO 2-4 SM BR BETWEEN SHOWERS IN A FEW
SPOTS. THE LATEST HRRR SOLUTIONS SHOW ABUNDANT MVFR CIGS
DEVELOPING THIS EVENING WITH AREAS OF IFR CIGS AROUND THE AREA
THROUGH THU MORNING. IT APPEARS THAT THERE WILL BE LITTLE SKILL
IN PINPOINTING WHERE THE LOWER CLOUDS WILL DEVELOP OR MOVE WITH THE
LIGHT FLOW AND DRIPS OF PRECIPITATION.

ANOTHER WEAK FRONTAL LIKE FEATURE CAN BE SEEN EXTENDING SE FROM 50N
145W. THIS FEATURE WILL MOST LIKELY STALL ALONG THE COAST THU
AFTERNOON AND EVENING AS LOW PRES MOVING INTO THE QUEEN CHARLOTTE
SOUND MIDDAY THU DROPS SSE INTO THE COASTAL WATERS THU NIGHT. THIS
WEAK FEATURE WILL HELP TO FOCUS PRECIPITATION OVER THE OLYMPIC
PENINSULA RESULTING IN MVFR TO LOCAL IFR CONDITIONS THERE. THE
INTERIOR MAY FARE SLIGHTLY BETTER...VFR WITH OCCASIONAL MVFR CIGS
AND VIS AS FLOW BECOMES WEAKLY OFFSHORE. ALBRECHT

KSEA...CONDITIONS WILL AVERAGE P6SM BKN015 OVC040 THROUGH THU
MORNING. LOW LEVEL CONVERGENCE CENTERED NEAR THE TERMINAL WILL
GIVE LIGHT WINDS. ALBRECHT

&&

.MARINE...WEAK FRONTAL FEATURES MOVING SE THROUGH THE WATERS WILL
DISSIPATE AS THEY MOVE TO THE COASTLINE TONIGHT THROUGH THU. EXPECT
LIGHT PRES GRADIENTS ACROSS THE WATERS. A DIFFUSE AND BROAD 1008 MB
LOW WILL DROP SSE FROM THE QUEEN CHARLOTTE SOUND MIDDAY THU THROUGH
THE COASTAL WATERS LATE THU NIGHT. LIGHT FLOW WILL DOMINATE AS THE
LOW PASSES...THEN WINDS WILL TURN NELY AS THE LOW MOVES S INTO
WESTERN OREGON.

HIGH PRES WILL BUILD OVER THE INTERIOR OF BRITISH COLUMBIA FRI. AS
THE LOW LATE THU NIGHT PASSES SOUTH OF THE AREA...EXPECT N TO NE
FLOW TO INCREASE. SMALL CRAFT ADVISORY CONDITIONS ARE LIKELY OVER
MOST OF THE WATERS FRI NIGHT INTO EARLY SAT. THERE IS A SMALL CHANCE
THAT GALE FORCE WINDS WILL OCCUR AROUND THE WEST ENTRANCE TO THE
STRAIT OF JUAN DE FUCA AND OVER PORTIONS OF THE NORTHERN INLAND
WATERS FRI NIGHT.

HIGH PRES WILL MOVE INTO THE WATERS ON SUN GIVING ANOTHER PERIOD OF
LIGHT WINDS.

ANOTHER LOW WILL DROP SOUTHEAST ACROSS THE AREA SUN NIGHT INTO MON
AND WILL BE FOLLOWED BY STRONG NE PRES GRADIENTS LATER MON OR MON
NIGHT. ALBRECHT

&&

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

&&

$$

WWW.WEATHER.GOV/SEATTLE/

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










000
FXUS66 KSEW 260434
AFDSEW

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SEATTLE WA
900 PM PST WED FEB 25 2015

.SYNOPSIS...A WEAK WEATHER SYSTEM WILL BRING RAIN AT TIMES TO
WESTERN WASHINGTON TONIGHT. RAIN WILL TRANSITION TO SHOWERS ON
THURSDAY AND PERSIST THROUGH FRIDAY. OFFSHORE FLOW AND AN UPPER
RIDGE WILL GIVE DRY WEATHER SATURDAY AND SUNDAY. A WETTER AND COOLER
PATTERN WILL RETURN EARLY NEXT WEEK.

&&

.SHORT TERM...LATEST RADAR AND OBS SHOW AREAS OF LIGHT RAIN ACROSS
WRN WA THIS EVENING. PRECIPITATION AMOUNTS SO FAR HAVE GENERALLY
BEEN UNDER ONE TENTH SINCE THIS MORNING...EXCEPT LOCALLY HIGHER
ALONG THE N COAST. SPOTTY LIGHT RAIN WILL CONTINUE THROUGH TONIGHT
AS A WEAK SURFACE TROUGH OFFSHORE DIGS SE OVER WRN WA/OREGON. SOME
WEAK CONVERGENCE IS OCCURRING AROUND THE CENTRAL PUGET SOUND
REGION...ESPECIALLY WRN KING COUNTY. THE HRRR SHOWS THIS CONTINUING
THROUGH LATE TONIGHT BEFORE DISSIPATING SO EXPECT STEADIER RAIN
AROUND SEATTLE.

MOIST NW FLOW ALOFT CONTINUES INTO THURSDAY AS A COOL UPPER TROUGH
OFF THE CENTRAL B.C. COAST BEGINS TO DIG SE TOWARD THE AREA. RAIN
WILL TRANSITION TO A MORE SHOWERY REGIME AS THE TROUGH APPROACHES
AND COOLER AIR ALOFT ARRIVES. MODELS SHOW A 500 MB -28C COLD POCKET
OVER THE REGION BY THURSDAY NIGHT SO THE ATMOSPHERE WILL BE
MARGINALLY UNSTABLE. THE CHANCE OF THUNDERSTORMS IN THE FORECAST FOR
THE COAST IS A BIT IFFY BUT WITH THE LOW OVERHEAD IT CANNOT BE RULED
OUT EITHER. WILL NOT MAKE ANY CHANGES.

SHOWERS DECREASE ON FRIDAY AS THE STACKED UPPER/SURFACE LOW SHIFT
SWD INTO OREGON. NLY FLOW WILL DEVELOP AND A 1035 MB SURFACE HIGH
WILL SETTLE INTO SRN B.C. SO EXPECT BREEZY NLY OUTFLOW WINDS TO PICK
UP. BY FRIDAY NIGHT...CLEARING SKIES ARE EXPECTED WITH COOLER
TEMPERATURES. BREEZY WINDS WILL HELP KEEP MOST PLACES JUST ABOVE
FREEZING. HOWEVER...SHELTERED LOCATIONS LIKE OLYMPIA WILL HAVE
TEMPERATURES CLOSER TO OR JUST BELOW THE FREEZING MARK SATURDAY
MORNING. LOW TEMPERATURES IN THE COLD POCKETS WILL NEED SOME
DOWNWARD ADJUSTMENT WITH THE NEXT FORECAST ISSUANCE. WITH HIGH
PRESSURE BUILDING ALOFT...CLEAR SKIES WILL PREVAIL ON SATURDAY WITH
HIGHS STRUGGLING TO REACH ABOVE 50.  MERCER

.LONG TERM...FROM PREVIOUS DISCUSSION...SUNDAY WILL BE MOSTLY SUNNY
AND TEMPERATURES WILL REBOUND A BIT. THE GFS AND EURO BOTH HAVE A
WEAK SYSTEM MOVING ALMOST DUE SOUTH ALONG THE COAST SUNDAY NIGHT AND
MONDAY. CHANCE POPS COVER THIS SYSTEM FOR NOW. AFTER IT PASSES
NORTHERLY AND OFFSHORE FLOW WILL AGAIN DEVELOP WITH MONDAY NIGHT AND
TUESDAY LOOKING BREEZY AND COOL. DRY WEATHER CONTINUES THROUGH
WEDNESDAY. HIGH TEMPERATURES ON TUESDAY AND WEDNESDAY WILL BE MOSTLY
IN THE 40S WITH LOWS IN THE 30S. BURKE

&&

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

&&

.AVIATION...NORTHWEST FLOW ALOFT. WEAK DISTURBANCES WILL MOVE SE
ACROSS THE AREA TONIGHT THROUGH THU. THEN A BROAD AND DIFFUSE 1008
MB LOW WILL MOVE SWD THROUGH THE COASTAL WATERS LATE THU NIGHT. THE
AIR MASS IS STABLE AND MOIST.

WHILE VFR CIGS AND VSBYS ARE MOST COMMON ACROSS THE AREA THIS
EVENING...CONDITIONS ARE MIXED. AN AREA OF SHOWERS ALONG THE COAST
IS GIVING LOCAL IFR CIGS AND VSBYS TO THE NORTH COAST. AN AREA OF
CONVERGENCE TO THE LEE OF THE MOUNTAINS OF VANCOUVER ISLAND IS
GIVING MVFR CIGS TO THE NORTHERN INTERIOR OF W WA FROM THE SAN JUAN
ISLANDS AND THE KBLI AREA SE INTO NORTHERN SNOHOMISH COUNTY. ANOTHER
NARROWER CONVERGENCE ZONE EXTENDS FROM E OF KSEA TO KSMP. BETWEEN
THE AREAS OF CONVERGENCE...CONDITIONS ARE VFR WITH CIGS AROUND
FL045. VIS IS OCNLY DROPPING TO 2-4 SM BR BETWEEN SHOWERS IN A FEW
SPOTS. THE LATEST HRRR SOLUTIONS SHOW ABUNDANT MVFR CIGS
DEVELOPING THIS EVENING WITH AREAS OF IFR CIGS AROUND THE AREA
THROUGH THU MORNING. IT APPEARS THAT THERE WILL BE LITTLE SKILL
IN PINPOINTING WHERE THE LOWER CLOUDS WILL DEVELOP OR MOVE WITH THE
LIGHT FLOW AND DRIPS OF PRECIPITATION.

ANOTHER WEAK FRONTAL LIKE FEATURE CAN BE SEEN EXTENDING SE FROM 50N
145W. THIS FEATURE WILL MOST LIKELY STALL ALONG THE COAST THU
AFTERNOON AND EVENING AS LOW PRES MOVING INTO THE QUEEN CHARLOTTE
SOUND MIDDAY THU DROPS SSE INTO THE COASTAL WATERS THU NIGHT. THIS
WEAK FEATURE WILL HELP TO FOCUS PRECIPITATION OVER THE OLYMPIC
PENINSULA RESULTING IN MVFR TO LOCAL IFR CONDITIONS THERE. THE
INTERIOR MAY FARE SLIGHTLY BETTER...VFR WITH OCCASIONAL MVFR CIGS
AND VIS AS FLOW BECOMES WEAKLY OFFSHORE. ALBRECHT

KSEA...CONDITIONS WILL AVERAGE P6SM BKN015 OVC040 THROUGH THU
MORNING. LOW LEVEL CONVERGENCE CENTERED NEAR THE TERMINAL WILL
GIVE LIGHT WINDS. ALBRECHT

&&

.MARINE...WEAK FRONTAL FEATURES MOVING SE THROUGH THE WATERS WILL
DISSIPATE AS THEY MOVE TO THE COASTLINE TONIGHT THROUGH THU. EXPECT
LIGHT PRES GRADIENTS ACROSS THE WATERS. A DIFFUSE AND BROAD 1008 MB
LOW WILL DROP SSE FROM THE QUEEN CHARLOTTE SOUND MIDDAY THU THROUGH
THE COASTAL WATERS LATE THU NIGHT. LIGHT FLOW WILL DOMINATE AS THE
LOW PASSES...THEN WINDS WILL TURN NELY AS THE LOW MOVES S INTO
WESTERN OREGON.

HIGH PRES WILL BUILD OVER THE INTERIOR OF BRITISH COLUMBIA FRI. AS
THE LOW LATE THU NIGHT PASSES SOUTH OF THE AREA...EXPECT N TO NE
FLOW TO INCREASE. SMALL CRAFT ADVISORY CONDITIONS ARE LIKELY OVER
MOST OF THE WATERS FRI NIGHT INTO EARLY SAT. THERE IS A SMALL CHANCE
THAT GALE FORCE WINDS WILL OCCUR AROUND THE WEST ENTRANCE TO THE
STRAIT OF JUAN DE FUCA AND OVER PORTIONS OF THE NORTHERN INLAND
WATERS FRI NIGHT.

HIGH PRES WILL MOVE INTO THE WATERS ON SUN GIVING ANOTHER PERIOD OF
LIGHT WINDS.

ANOTHER LOW WILL DROP SOUTHEAST ACROSS THE AREA SUN NIGHT INTO MON
AND WILL BE FOLLOWED BY STRONG NE PRES GRADIENTS LATER MON OR MON
NIGHT. ALBRECHT

&&

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

&&

$$

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