Small Craft Advisory 257, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
316 PM AKDT SUN MAR 13 2016

.SHORT TERM...THE WEATHER PATTERN FOR THE NEXT 24 HOURS IS RATHER
STATIC. A SLOWLY WEAKENING LOW WEST OF HAIDA GWAII IS NEARLY
STATIONARY AND CONTINUES TO SEND WEAK SHORT WAVES INTO THE
SOUTHERN PANHANDLE. THESE AREAS HAVE SEEN ON AND OFF SHOWERS FOR
MOST OF THE DAY WITH SOME OCCASIONAL BREEZY WINDS AS WELL.
FARTHER NORTH A WEAK UPPER TROUGH IS MOVING WEST AND CURRENTLY
JUST BRUSHING THE NORTHERN PANHANDLE. NOT MUCH WITH THIS SYSTEM
EXPECT FOR SOME HIGH CLOUDS FILTERING OUT THE SUN FOR HAINES AND
SKAGWAY. THE REST OF THE NORTHERN PANHANDLE IS ENJOYING PARTLY
CLOUDY TO MOSTLY SUNNY SKIES DUE TO EASTERLY OFFSHORE FLOW ACROSS
THE AREA.

FOR TONIGHT INTO TOMORROW, LOW WEST OF HAIDA GWAII WILL SLOWLY
DRIFT TO THE NORTH EVENTUALLY BEING WEST OF PRINCE OF WALES ISLAND
BY MON AFTERNOON. WEAK SHORT WAVES AND FRONTAL BANDS WILL CONTINUE
TO BE SENT INTO THE SOUTHERN PANHANDLE BRINGING MORE RAIN SHOWERS
AND SOME BREEZY WINDS. HIGHEST WINDS ARE EXPECTED DURING THE DAY
MONDAY AS THE LOW MAKES ITS CLOSEST APPROACH TO THE COAST BEFORE
IT WEAKENS COMPLETELY. WINDS OF 30 KT ARE EXPECTED FOR THE SE GULF
WATERS AND CLARENCE STRAIT TOMORROW WHILE THE LAND AREAS WILL
MAINLY SEE GUSTS TO 30 OR 35 MPH. SHOWERS WILL LIKELY ONLY GET AS
FAR NORTH AS FREDERICK SOUND AS EASTERLY FLOW IMPEDES ANY
PROGRESS OF THE SHOWERS FARTHER NORTH. SOME ISOLATED THUNDERSTORMS
ARE NOT OUT OF THE QUESTION FOR THE SOUTHERN GULF AND SOUTHERN
PANHANDLE AS THE ATMOSPHERE NEAR THE LOW IS RATHER UNSTABLE. NO
LIGHTNING DETECTED TODAY BUT THE VARIOUS SHOWERS HAVE SHOWED
RATHER COLD CLOUDS TOP TEMPS.

FARTHER NORTH, NEXT 24 HOURS WILL MAINLY BE DRY WITH SOME HIGH TO
MID LEVEL CLOUDS FILLING IN THE SKY THROUGH TOMORROW AFTERNOON.
TEMPS ONCE AGAIN WILL FALL BELOW FREEZING FOR LOWS OVERNIGHT
BEFORE REBOUNDING INTO THE 40S AGAIN TOMORROW. WINDS WILL MOSTLY
BE 20 MPH OR LESS FOR MOST AREAS AS PRESSURE GRADIENTS REMAIN
LOW.

SHORT RANGE MODELS REMAIN IN DECENT AGREEMENT. CHANGES OVER
PREVIOUS FORECAST WAS A SLIGHT EASTWARD TREND TO LOW TRACK. ALSO
RAISED TEMPERATURES FOR TOMORROW 2 TO 3 DEGREES ACROSS THE
NORTHERN PANHANDLE AS MODEL GUIDANCE LATELY HAS TRENDED TOO COLD
FOR HIGHS IN THE NORTHERN PANHANDLE. USED MAINLY ECMWF AND GFS FOR
ANY UPDATES TODAY.

.LONG TERM...THE LONG TERM FORECAST WILL CALL FOR THE RETURN TO
WETTER WEATHER ACROSS THE PANHANDLE.

THE START OF THE LONG TERM FORECAST PERIOD WILL FEATURE A WEAK
LOW COMING UP ALONG THE OUTER COAST MONDAY NIGHT, THEN WEAKEN NEAR
BARANOF ISLAND BY TUESDAY MORNING. PRECIPITATION WILL BE SPREADING
FROM SOUTH TO NORTH FROM MONDAY EVENING INTO TUESDAY. AS THE LOW
WEAKENS, HIGH PRESSURE WILL BUILD IN FROM THE SOUTH ON TUESDAY,
AND THAT WILL BRING IN A BURST OF STRONGER SOUTHERLY WIND FOR THE
SOUTHERN AND CENTRAL PANHANDLE ON TUESDAY.

PRECIPITATION WILL CONTINUE FROM TUESDAY INTO WEDNESDAY. THE
PRECIPITATION WILL SHIFT MORE TOWARDS THE YAKUTAT AREA STARTING ON
WEDNESDAY NIGHT, WITH SOME BREAKS IN THE PRECIPITATION AND SKY
COVER OVER THE SOUTHERN PANHANDLE FROM WEDNESDAY NIGHT INTO THE
END OF THE WORK WEEK.

PRECIPITATION TYPE SHOULD BE MAINLY RAIN FOR MOST OF THE
PANHANDLE LOCATIONS. FOR SKAGWAY, HAINES, AND THE HIGHWAYS THE
MAIN PRECIP TYPE WILL BE SNOW WITH RAIN MIXED IN. DAYTIME HIGH
TEMPERATURES SHOULD BE IN THE 40S, WITH OVERNIGHT LOW TEMPERATURES
IN THE 30S.

FORECAST CONFIDENCE IS ABOUT AVERAGE. NUMERICAL WEATHER MODELS ARE
IN GENERAL AGREEMENT ON THIS WEATHER PATTERN. DECIDE TO USE A
BLEND OF ECMWF/NAM THROUGH WEDNESDAY NIGHT, THEN TRANSITION TO WPC
GUIDANCE.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ022-033-035-036-041>043.
     SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ051-052.
&&

EAL/RCL

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