Gale Warning 334, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
600 AM AKST TUE NOV 4 2014

.SHORT TERM...MONDAY NIGHT'S STORM WAS A LITTLE WEAKER THAN
EXPECTED, TOOK A MORE EASTWARD TRACK THAN EXPECTED, AND MOVED
INTO THE PANHANDLE A LITTLE FASTER THAN EXPECTED. LITTLE
VARIATIONS ON ALL THESE PARAMETERS HAD LARGE RAMIFICATIONS FOR THE
PREDICTED HIGH WIND EVENT. ALTHOUGH STRONG WINDS WERE RECORDED IN
KLAWOCK, KETCHIKAN, ANNETTE, METLAKATLA, AND EVEN PETERSBURG, HIGH
WIND GUSTS WERE NOT REALIZED. IN ADDITION, BECAUSE OF THE MORE
EASTWARD TRACK OF THE STORM OVER CAPE DECISION, SITKA LARGELY
AVOIDED ANY SOUTHEAST WINDS. WITH THE SECOND WRAP FEATURE BEHIND
THE STORM, SITKA IS NOW EXPERIENCING STRONG WINDS FROM THE
SOUTHWEST...THESE SHOULD PERSIST THROUGH THE EARLY MORNING BEFORE
DIMINISHING THROUGH THE DAY. AN ASSOCIATED GALE FOR MARINE ZONES
42 AND 310 WILL FADE LATER THIS MORNING.

NONE OF THE MODELS HAVE SUCCESSFULLY CAPTURED THE SYSTEM'S SPEED.
MSAS ANALYSIS HAS TAKEN THE SYSTEM NOW NORTH OF POINT RETREAT, AND
THUS LATE CHANGES WERE MADE TO THE FORECAST REGARDING SOUTHERLY
FLIPS IN THE NORTHERN PANHANDLE. CONFIDENCE NOT GREAT WITH
MAGNITUDES THIS AFTERNOON. MODEL GRADIENTS NOT SUPER IMPRESSIVE,
SO IT ALL DEPENDS ON THE NORTHWARD PROGRESSION OF THE SYSTEM AND
HOW QUICKLY PRESSURES RISE IN THE SYSTEM'S LEE. STARTED THIS
MORNING WITH A PLETHORA OF SMALL CRAFTS THROUGH THE NORTH-SOUTH
INSIDE CHANNELS, AND CULMINATING WITH SOLID SMALL CRAFTS TO 30 KT
TONIGHT FOR LYNN CANAL. MEANWHILE, RAISED CROSS SOUND TO
SOUTHWESTERLY SMALL CRAFT. EVEN AS THIS SPOT NORMALLY GALES FROM
THE SOUTHWEST BEHIND MANY A SYSTEM, FEEL THE WEAKENING OF THE
STORM MOVING INLAND AND THE DEVELOPMENT OF A WEAK LOW IN THE
NORTHERN GULF MAY INHIBIT GALE DEVELOPMENT. WEAKENING WINDS WILL
REMAIN SOUTHERLY THROUGH TONIGHT AS THE MEGA SYSTEM DISCUSSED
BELOW WILL HAVE NOT INFLUENCED THE GRADIENT ENOUGH TO DEMAND
DIRECTIONAL FLIPS TO THE NORTH.

LOTS OF COOLER, UNSTABLE AIR (500 MB TEMPERATURES LOWER THAN
-30 C) HAS BEEN ENVELOPED WITH THIS SYSTEM AND THUS WE HAVE A
SLIGHT CHANCE OF THUNDERSTORMS OVER A WIDE AREA OF THE GULF WITH
THE THREAT SPREADING INLAND FROM COASTAL AREAS THROUGH THE DAY. A
CLUSTER OF THUNDERSTORMS DID DEVELOP OVERNIGHT OFFSHORE OF
FAIRWEATHER.

USED A BLEND OF NAM, HIGH RES NMM, HIGH RES ARW, AND ECMWF FOR
CHANGES. FORECAST CONFIDENCE BELOW AVERAGE FOR TIMING OF SPEED
RISES IN THE NORTH THIS AFTERNOON. GOOD FOR MOST OTHER ELEMENTS.

.LONG TERM...THE BIG ISSUE IN THE MID RANGE WILL BE THE VERY
STRONG LOW THAT WILL MOVE INTO THE SOUTHEAST GULF WEDNESDAY
AFTERNOON AND OVER THE AREA THAT NIGHT. THE LOW IS FORMING THIS
MORNING IN THE NORTH PACIFIC AS SEEN ON SATELLITE IMAGERY FROM THE
BAROCLINIC LEAF SIGNATURE. THERE WILL BE VERY STRONG CYCLOGENISIS
AS UPPER LEVEL DYNAMICS FROM THE BERING DIGS INTO THE NORTH
PACIFIC AND INTERACTS WITH THE TROPICAL AIR BEING ADVECTED
NORTHWARD. THE DYNAMICS ALONG WITH A VERY STRONG 150KT JET WILL
ALLOW THIS LOW TO DEEPEN TO THE LOWER 970MBS BY WEDNESDAY
AFTERNOON AS IT LIFTS INTO THE SOUTHEAST GULF. THE LOW WILL MOVE
OVER THE CAPE DECISION AREA AND THEN INTO THE CENTRAL PANHANDLE
AND WEAKEN AS IT CONTINUES TO DRIFT NNE AND INTO CANADA WEDNESDAY
NIGHT. THIS SYSTEM HAS TROPICAL ORIGINS AND WILL BE ADVECTING VERY
HIGH PRECIPITABLE VALUES OVER THE AREA WITH THE WARM FRONT. THE
MODELS ARE IN GOOD AGREEMENT WITH THE 12Z NAM COMING IN LINE WITH
THE MORE CONSISTENT AND FAVORED 00Z GEM. THIS HAS LED TO INCREASE
CONFIDENCE ON THE TRACK AND STRENGTH THAT A HIGH WIND WATCH HAS
BEEN ISSUED FROM THE SOUTHERN HALF OF THE FORECAST AREA.

SO WITH THAT SAID...THE WINDS WILL INCREASE THROUGH THE DAY OVER
THE SOUTHEAST GULF TO STORM FORCE FROM THE ESE BY THE AFTERNOON.
THE
SOUTHERN INNER CHANNELS WILL SEE THE CONDITIONS BUT FROM SUMNER
STRAIT NORTHWARD THE WINDS WILL BE INCREASING FROM THE NORTH TO
RANGE FROM 30 TO 35 KT BY THE AFTERNOON. LAND WINDS WILL INCREASE
TO 20 TO 30 MPH WITH GUSTS RANGING FROM 45 TO 55 MPH BUT GUSTS
HIGHER THAN 60 MPH IS POSSIBLE FOR THE SOUTHERN HALF FROM
WEDNESDAY AFTERNOON TO THE EVENING. THE WINDS OVER THE NORTHERN
HALF LAND AREAS WILL SEE GUSTY WINDS BUT IT WILL BE LOCALIZED AND
BE IN THE RANGE OF 30 TO 40 MPH. THE TIGHT PRESSURE GRADIENT MAY
PRODUCE SOME HIGHER GUSTS NEAR THE JUNEAU AREA. AS THE LOW LIFTS
INLAND THROUGH THE EVENING TIME FRAME THERE WILL BE ANOTHER LARGE
INCREASE IN WINDS BUT FROM THE SSW BEHIND THE LOW AND FROM THE
STRONG PRESSURE RISES. SO THE STRONG TO HIGH WINDS WILL PERSIST
THROUGH THE EVENING HOURS AND THE WINDS WILL SWITCH FROM N TO S
OVER THE CENTRAL AREAS. THE LAND FALLING LOW WILL BE NEAR THE HIGH
TIDE ON WEDNESDAY NIGHT AND MAY CAUSE SOME COASTAL FLOODING THAT
COMMUNITIES WILL NEED TO WATCH OUT FOR. THE WINDS WILL SLOWLY
DIMINISH TO BE LESS THAN GALES FROM THE SOUTH BY LATE WEDNESDAY.
THE FAR NORTHERN AREAS WILL REMAIN TO SEE SOME NORTHERLY WINDS.

THE RAIN ACROSS THE AREA WEDNESDAY MORNING WILL SLOW DIMINISH OVER
THE NORTHERN AREAS WITH SOME SUN COMING OUT OVER THE FAR NORTHERN
INNER CHANNEL AND NORTHERN GULF WITH OFFSHORE FLOW. THE SOUTHERN
AREAS WILL SEE HEAVY RAIN MOVE INTO THE AREA WITH THE WARM FRONT
BY THE AFTERNOON WITH STRONG RAIN RATES. THE HIGH RAIN RATES ALONG
WITH THE VERY STRONG WINDS WILL INCREASE THE THREATS OF MUDSLIDES
NEAR THE STEEP TERRAIN. RAIN AMOUNTS WILL RANGE FROM 1 TO 3 INCHES
BY WEDNESDAY NIGHT OVER THE SOUTHERN HALF. THE RAIN WILL MAKE IT
OVER THE NORTHERN HALF THROUGH THE EARLY EVENING. THE FAR NORTHERN
AREAS MAY SEE SOME SNOW WEDNESDAY NIGHT WITH COOLER AIR AND WINDS
FROM THE NORTH. THE HIGHEST AMOUNTS 1 TO 3 INCHES WILL BE ALONG
THE HIGHWAYS ESPECIALLY THE HAINES HIGHWAY.

THURSDAY MORNING THROUGH NEXT TUESDAY NIGHT...

WEATHER PATTERN REMAINING ACTIVE FOR THE START OF THE LONG TERM
PERIOD. WINDS WILL START TO DIMINISH DURING THE MORNING HOURS ON
THURSDAY AS THE FORMER STORM FORCE LOW CONTINUES TO MOVE INLAND
INTO INTERIOR BRITISH COLUMBIA AND RAPIDLY WEAKENS. SOUTHERLY
WINDS WILL PERSIST IN THE INSIDE PASSAGE SOUTH OF JUNEAU. FOR LYNN
CANAL, NORTHERLY WINDS WILL SWITCH TO BECOME SOUTHERLY BRIEFLY
DURING THE DAY ON THURSDAY. SHOWERS, HOWEVER WILL CONTINUE ON
THURSDAY. SNOW LEVEL WILL REMAIN LOW ENOUGH FOR SNOW TO TAKE PLACE
ALONG THE NORTHERN BORDER. SNOW ACCUMULATION SHOULD BE MINOR.

 THE NEXT BIG WEATHER MAKER WILL BE A BROAD LOW PRESSURE AREA
MOVING INTO THE WESTERN GULF OF ALASKA. THIS LOW IS FORECASTED TO
HAVE SUB 980 MB PRESSURE. A STRONG WEATHER FRONT ASSOCIATED WITH
THIS LOW IS EXPECTED TO MAKE LANDFALL ALONG THE EASTERN GULF COAST
BY FRIDAY MORNING. DO EXPECT SOUTHEASTERLY GALE FORCE WINDS ON THE
OUTSIDE COASTAL WATERS. STRONG WIND GUSTS ARE ALSO EXPECTED ALONG
THE OUTER COAST. WITH MOISTURE PLUME ORIGINATING FROM THE
SUBTROPICS, DO EXPECT 1 TO 2 INCHES OF RAINFALL. HEAVIEST
PRECIPITATION SHOULD BE FOUND IN THE SOUTHERN PANHANDLE.

 FOR THE WEEKEND, MODELS ARE HINTING ON THE WEATHER PATTERN
BECOMING LESS ACTIVE. THE REMNANT OF TYPHOON NURI IS EXPECTED TO
HEAD TOWARDS THE BERING SEA. SELECTED NUMERICAL MODELS ARE
INDICATING NURI WILL BECOME A FAIRLY POTENT EXTRATROPICAL SYSTEM,
AND IT WILL HELP BUILD A RIDGE OF HIGH PRESSURE OVER EASTERN
ALASKA. THIS MEANS THAT THERE WILL BE POTENTIAL DRYING FOR THE
PANHANDLE THIS WEEKEND.
&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...HIGH WIND WATCH FROM WEDNESDAY AFTERNOON THROUGH WEDNESDAY

     EVENING FOR AKZ023-026>028.
         STRONG WIND UNTIL 9 AM AKST THIS MORNING FOR AKZ023.
MARINE...GALE WARNING FOR PKZ042.
         SMALL CRAFT ADVISORY FOR
PKZ012-013-022-031>036-041-043-051-052.

&&

JWA/ABJ/RCL

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