Small Craft Advisory 187, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
144 PM AKST WED FEB 23 2011

.SHORT TERM...HIGH PRESSURE CENTERED OVER THE WESTERN GULF AND
NORTHWEST CANADA THE DOMINATE WEATHER FEATURES THROUGH THURSDAY
AFTERNOON...AND BEYOND. A WEAK INVERTED THROUGH EXTENDS FROM THE
BRITISH COLUMBIA COAST NORTHWEST ALONG THE PANHANDLE TOWARD
PRINCE WILLIAM SOUND. ON VISIBLE SATELLITE IMAGERY NEARLY CLEAR
SKIES OVER THE PANHANDLE WITH A LARGE REGION OF CLOUD STREETS
FROM DIXON ENTRANCE WEST NORTHWEST TO THE CENTRAL GULF. A SMALL
LOW LEVEL LOW IS BEGINNING TO FORM JUST SOUTHWEST OF ICY BAY OVER
NORTHERN GULF...JUST SOME STRATUS FORMING ASSOCIATED WITH THAT.
OVER THE INTERIOR PORTION OF THE STATE CIRRUS DECK FROM THE TRAIN
OF LOWS OVER THE WESTERN BERING TO THE CHUKCHI SEA AND ACROSS THE
ARCTIC OCEAN.

 PRESSURE GRADIENTS OVER THE NORTHERN PANHANDLE RELAXING AS THE
BUBBLE OF HIGH PRESSURE IN THE YUKON MOVES SOUTHEAST THROUGH
NORTHERN BRITISH COLUMBIA...AND MOVING THE AREA OF GUSTY OUTFLOWS
FURTHER TO THE SOUTH FOR THE STIKINE VALLEY...BEHM AND PORTLAND
CANALS. WILL STILL SEE SOME LOCALLY GUSTY WINDS BUT NOT EXPECTED
MORE FREQUENT GUSTS TO WARRANT AN ADVISORY AND THINK MOST WILL BE
LESS THAN 40 MPH ANYWAY.

 WILL BE STARTING WITH GALE FORCE WINDS IN NORTHERN LYNN CANAL
AND CROSS SOUND AREA FOR THIS EVENING BUT THEY WILL BE
DIMINISHING BY SUNRISE THURSDAY. OLD TEMPERATURES LEADING TO SOME
AREAS OF FREEZING SPRAY INTO THURSDAY THAT WILL BE SUBSIDING AS
WINDS DO ON THURSDAY.

&&

.LONG TERM...MODELS ARE IN GENERAL AGREEMENT IN SYNOPTIC SCALE
WITH AN UPPER HIGH ACROSS THE GULF OF ALASKA MOVING SLIGHTLY SOUTH
THROUGH SATURDAY MORNING AS AN UPPER SHORTWAVE TROUGH MOVING
SOUTHEAST FROM ALASKAN INTERIOR. THIS SHORTWAVE TROUGH WILL
CONTINUE TO DOMINATE THE FORECAST DOMAIN THROUGH WEDNESDAY NEXT
WEEK BEFORE MOVING SOUTHEAST ON THURSDAY. AN OMEGA BLOCK PATTERN
WILL RETURN TO THE WESTERN ALASKA OVER THE WEEKEND AND EARLY NEXT
WEEK AND CONTINUE THROUGH THE WORK WEEK...BLOCKING ANY STORM
SYSTEMS COMING INTO ALASKA. AT THE LOWER LEVELS...SURFACE HIGH
PRESSURE IN THE GULF WILL ALSO MOVE SLIGHTLY SOUTH THROUGH
SATURDAY MORNING...ALLOWING A FRONTAL BOUNDARY ASSOCIATED WITH A
LOW TRACKING SOUTH ACROSS THE PANHANDLE FROM FRIDAY NIGHT THROUGH
SATURDAY NIGHT. RELATIVELY WARM AIR MASS WILL ACCOMPANY THE FRONT
WITH SNOW LINE MOSTLY CONFINED NORTH OF A LINE FROM GUSTAVUS TO
JUNEAU AND EASTERN PANHANDLE NEAR COAST MOUNTAIN WITH NO
CONSIDERABLE SNOW ACCUMULATION. REGENERATED GRIDS WITH THE NAM12
THROUGH SATURDAY NIGHT THEN BLENDED 50/50 OF THE GFS AND ECMWF
THROUGH THE END OF THE PERIOD.

 THE LOW WILL BECOME NEARLY STATIONARY OVER DIXON ENTRANCE AND
NEAR THE QUEEN CHARLOTTES ON SUNDAY THEN WEAKEN AND MOVE SLIGHTLY
SOUTHWEST ACROSS THE SOUTHEASTERN GULF MONDAY NIGHT THROUGH
WEDNESDAY. PRECIPITATION BAND WILL MOVE SOUTHEAST THROUGH SUNDAY
WITH CLEARING OUT ACROSS THE NORTHERN PANHANDLE AS EARLY AS LATE
SATURDAY INTO SATURDAY NIGHT. AS THE LOW CONTINUES MOVING
SOUTHWEST...SOUTHERN AREAS WILL ALSO CLEARING OUT BY SUNDAY NIGHT.
AN INVERTED TROUGH OF LOW PRESSURE WILL EXTEND NORTHWESTWARD FROM
THE LOW IN THE SOUTHEASTERN GULF TUESDAY NIGHT INTO WEDNESDAY WITH
INCREASING CLOUDS ALONG THE PANHANDLE COAST AND SOUTHERN HALF OF
SOUTHEAST ALASKA. HIGH PRESSURE BUILDING ACROSS THE INTERIOR AND
YUKON OVER THE WEEKEND WILL SLIDE SOUTHEAST THROUGH TUESDAY WITH
INCREASING NORTHERLY PRESSURE GRADIENT WITH COLD OUTFLOW ACROSS THE
FORECAST DOMAIN...SUPPRESSING PRECIPITATION WITH STRONG
SUBSIDENCE. NORTH TO NORTHEAST GALE FORCE WINDS WILL PREVAIL
ACROSS THE COASTAL WATERS AND ADVISORY LEVEL WIND GUSTS WILL WIDELY
SPREAD ACROSS THE INNER CHANNELS WITH POSSIBLE STRONG TAKU
SCENARIO AND WARNING LEVEL WINDS ACROSS THE CENTRAL PANHANDLE.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...HEAVY FREEZING SPRAY WARNING FOR PKZ011-012-031.
         HEAVY FREEZING SPRAY WARNING FOR PKZ013.
         GALE WARNING FOR PKZ011-012-022.
         SMALL CRAFT ADVISORY FOR PKZ013-021-031-032-034>036-041>043.

&&

BEZENEK/AHN