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000
FXAK67 PAJK 202342
AFDAJK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
342 PM AKDT SUN APR 20 2014

.SHORT TERM...SATELLITE IMAGERY THIS AFTERNOON SHOWING TWO LOW
PRESSURE SYSTEM IN THE SOUTHERN AK GULF/NORTHER PACIFIC ROTATING
AROUND EACH OTHER. THE FIRST OF THE TWO SYSTEM IN THE
SOUTHWESTERN GULF PUSHES A FRONTAL BOUNDARY OVER THE PANHANDLE
LAST NIGHT INTO THE EARLY MORNING. SOUTHERLY WINDS PICKED UP TO
THE 15 TO 25 MPH RANGE WITH HIGHER GUSTS AS THE FRONT PUSHED
NORTHWARD. WINDS HAVE STARTED TO DIE DOWN THIS AFTERNOON AND WILL
FLIP BACK TO THE NORTH EARLY THIS EVENING AS THE SECOND LOW
PRESSURE SYSTEM MOVES IN. SOME UNCERTAINTY ON THE EXACT TIMING OF
THE WIND SHIFT. THIS NEXT LOW WILL TRACK FROM THE N PACIFIC TO
THE WEST OF PRINCE OF WALES ISLAND THIS EVENING. THE LOW WILL
THEN MOVE INTO THE NORTHEASTERN GULF THROUGH MONDAY, WEAKENING TO
AN OPEN WAVE TROUGH. THE ASSOCIATED FRONT IS JUST MOVING INTO THE
SOUTHERN PANHANDLE AND WILL BRING ANOTHER ROUND OF GUSTY WINDS
TOT HE SOUTHERN PANHANDLE THIS EVENING, THEN TO THE CENTRAL
PANHANDLE LATER IN THE NIGHT. 850 MB WINDS IN THE 50 KT RANGE
NEAR AKZ028 ARE ENOUGH TO WARRANT A STRONG WIND HEADLINE FOR THAT
REGION AND GALES FOR CLARENCE STRAIT. THE ORIENTATION OF THIS LOW
LEVEL JET SHOULD KEEP THE GUSTS FOR THE SURROUNDING AREAS JUST
BELOW THE 40 MPH THRESHOLD.

LIGHT RAIN OVER THE PANHANDLE DIMINISHED FROM SOUTH TO NORTH
EARLY THE MORNING WITH CLEARING SKIES BEHIND THE FRONT. THESE
CLEAR SKIES WILL BE SHORT LIVED THIS EVENING AS THE NEXT FRONT
PUSHED NORTHWARD. MAJORITY OF PRECIP WITH THE NEXT FRONT WILL BE
OVER THE SOUTHERN AND COASTAL PANHANDLE AS THE PARENT LOW PULLS
OFF TO THE NORTHWEST AND THE FRONT SHEARS APART. COLD AIR BEHIND
THE FRONT WILL BEGIN TO TRANSITION STRATIFORM PRECIP TO SHOWERS.
SKIES WILL BEGIN TO CLEAR AGAIN THROUGH MONDAY AFTERNOON INTO THE
EVENING AS THE FRONT WEAKENS AND EXITS THE REGION. SEASONABLY
NORMAL TEMPERATURES WILL MOSTLY BE EFFECTED BY WHAT CLOUD COVER
THERE IS, LESS COOLING TONIGHT FOR LOCATIONS WHERE OVERCAST SKIES
DEVELOP AND MORE HEATING ON MONDAY WHERE CLEAR BREAKS DEVELOP
EARLY.

ECMWF HAS REMAINED THE MODEL OF CHOICE DUE TO CONSISTENCY AND
GOOD INITIALIZATION. DIFFERENCES BETWEEN THE 00Z AND 12Z ECMWF
WERE MINOR, SO UPDATES TO THE FORECAST WERE LIMITED. THE 12Z
GFS/GEM WERE CLOSE TO THE ECMWF AND SUPPORTED THE WIND AND
PRESSURE PATTERN. THE NAM AS CONTINUED TO BE AN OUTLIER KEEPING
THE NEXT SYSTEM TOO FAR OT THE SOUTH THROUGH MONDAY. THE ECMWF POP
FIELD DID LOOK A BIT HIGH, ESPECIALLY OVER THE NORTHERN PANHANDLE,
SO TEMPERED IT WITH SOME GFS. FORECAST CONFIDENCE IS ABOVE
AVERAGE.

&&

.LONG TERM...THE SEMI STABLE WEATHER PATTERN THAT BEEN OCCURRING
OVER THE REGION. THE LOW PRESSURE THAT HAD BEEN PRESENT IN THE
GULF OF ALASKA WILL BE WEAKENING AND DISSIPATING THROUGH THROUGH
TUESDAY MORNING. A STRONGER LOW WILL REMAIN POSITIONS ALONG
ALEUTIAN CHAIN WHILE SPREADING A TROUGH/FRONTAL BOUNDARY ACROSS
THE WESTERN GULF AND INTO SOUTHERN GULF OF ALASKA. THE UPPER
LEVEL FLOW PATTERN IS STAYING ACROSS THE MID PACIFIC SO THE TRIPLE
POINT ENERGY WILL CONTINUE TO TRACK EAST AND SHOULD BE CUT OFF
FROM THE PARENT LOW BY EARLY THURSDAY SOUTH OF HAIDA GWAII.

GENERAL HIGH PRESSURE WILL CONTINUE OVER NORTHERN AND NORTHWESTERN
CANADA FROM MID WEEK TO THE END OF THE WEEK. THIS COMBINED WITH
WITH THE STORM TRACK WELL SOUTH OF THE PANHANDLE WILL LEAD TO A
RELATIVELY BENIGN WEEK. OVERALL THE WEATHER SHOULD BE SPRING LIKE. THE
MAIN HASSLES MAY BE HOW MUCH CLOUDS AND MOISTURE IS AROUND. DIDN`T
METTLE WITH TEMPERATURE AND POPS MUCH FOR THE LATER TIME STEPS IN
THIS WEAKER FLOW PATTERN FOR THE LATER TIME STEPS. FORECAST
CONFIDENCE IS LIGHTLY BETTER THAN AVERAGE TO TUESDAY AND THEN
LOWERS TO BELOW AVERAGE FOR THE END OF THE WEEK WITH THE WEAK FLOW
REGIME IN PLACE.


.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND FROM 10 PM THIS EVENING TO 1 AM AKDT MONDAY FOR
     AKZ028.
MARINE...GALE WARNING FOR PKZ036-052.
         SMALL CRAFT ADVISORY FOR PKZ022-033>035-041>043-051.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ053.

&&

$$

PRB/BEZENEK






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