Gale Warning 411, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
334 PM AKST SUN NOV 13 2011

.SHORT TERM...A STRONG WLY FLOW WILL CONTINUE WITH A COUPLE OF
SHORTWAVES MOVING THRU THE AREA TONIGHT AND MON. FIRST SHORTWAVE
WILL MOVE ACROSS THE CENTRAL AND SRN AREA THIS EVENING...THEN
SECOND ONE WILL MOVE THRU THE AREA MON. ARCTIC FRONT WILL DRIFT
SWD INTO THE FAR NRN PANHANDLE BY EARLY THIS EVENING...AND REMAIN
OVER THE FAR NRN AREA THRU MON.

MAIN FORECAST ISSUES WILL BE WINDS AND PRECIP TYPE. ATTM
STRONGEST BAND OF WLY WINDS EXTENDS FROM THE CENTRAL GULF TO THE
CENTRAL OUTER COAST. EXPECT THIS BAND TO REMAIN THERE INTO MON BUT
A SLOW WEAKENING TREND IS EXPECTED. WILL KEEP STORM GOING FOR THE
OFFSHORE WATERS AND CENTRAL COASTAL WATERS...WITH GALES IN
SURROUNDING GULF ZONES. FOR THE INNER CHANNELS...WILL KEEP GALE
FOR CROSS SOUND AND WRN END OF ICY STRAIT...WITH SCA FOR THE SRN
INNER CHANNELS. THE REMAINDER OF THE AREA SHOULD REMAIN BELOW SCA
LEVELS FOR THE MOST PART BUT AN OCCASIONAL PERIOD OF SCA WINDS IS
POSSIBLE ESPECIALLY CENTRAL INNER CHANNELS. THE SCA GOING ON IN
LYNN CANAL ATTM SHOULD WEAKEN THROUGH THE AFTERNOON.

AS FOR PRECIP TYPE...BASED ON 850 MB TEMPS AND 1000-850
THICKNESS...SNOW SHOWERS ARE FAVORED BUT SOME MIXED PRECIP IS
LIKELY OVER THE SRN HALF OF THE AREA DUE TO FAIRLY WARM BOUNDARY
LAYER TEMPS. SLOW COOLING OF THE LOWER LEVELS IS EXPECTED TONIGHT
SO ONLY THE FAR SRN AREA SHOULD STILL SEE MIXED PRECIP BY LATE
TONIGHT. ON MON THE LOWER LEVEL FLOW STARTS TO SLOWLY BACK OVER
THE GULF SO SOME MODERATION OF THE LOWER LEVEL TEMPS IS
LIKELY...SO MORE RAIN SHOULD MIX IN FURTHER TO THE N
MON...PROBABLY AS FAR N AS THE FREDERICK SOUND AREA.

OTHERWISE...GIVEN SHOWERY NATURE OF PRECIP...NAILING DOWN SNOW
ACCUMS WILL BE TRICKY. THINK MOST AREAS THAT REMAIN ALL SNOW WILL
SEE 1 TO 3 INCHES THRU MON BUT LOCALIZED HIGHER AMOUNTS ARE
POSSIBLE WHERE SHOWERS OCCUR THE MOST. POPS WILL BE CATEGORICAL
FOR MOST AREAS BUT FOR THE FAR N WILL KEEP POPS IN THE CHANCE
RANGE.

.LONG TERM...A TWO STEP COOLING TREND SET TO OCCUR WITH THE
FIRST BEGINNING TO OCCUR DURING THE SHORT RANGE PERIODS ABOVE
AND CONTINUING THROUGH TUE. THE SECOND STEP IN THE COOLING
TREND IS A LARGE SCALE ARCTIC OUTBREAK BEGINNING TUE NIGHT.
PRIMARY CHANGES TO THE LONG RANGE PACKAGE HAVE BEEN FOR STRONGER
WINDS AND LOWER TEMPERATURES WITH THE ARCTIC OUTBREAK. CONFIDENCE
IS AVERAGE.

THE CLOUD COVER WITH THE ARCTIC OUTBREAK WED WILL BE SLOW TO
LOSE CLOUD COVER. THE MODEL CONSENSUS IS GOOD THAT A 500 MB
TROUGH WILL BE CONTINUING TO EXTEND S FM OVER PAMD AND SUPPORTING
A 995 MB LOW ABOUT 100 NM S OF PAYA WITH A LARGE SCALE CIRCULATION.
THIS LARGE SCALE CIRCULATION WILL SUPPORT MIDDLE AND UPPER
CLOUD CIGS THAT WILL DIMINISH IN COVERAGE IN A N TO S SEQUENCE
WED THROUGH THU.

BOTH THE EC AND NAM WERE USED. FOR 00Z WED THE IN THE GULF THE
GFS IS AN OUTLIER COMPARED TO THE EC/NAM/UK. EC IS ALSO
SIGNIFICANTLY SLOWER TO WEAKEN THE ARCTIC HIGH IN YUKON TRRTY LATE
IN THE WEEK AND THIS SOLUTION IS PREFERRED.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND UNTIL 6 PM AKST THIS EVENING FOR AKZ022.
         STRONG WIND UNTIL MIDNIGHT AKST TONIGHT FOR AKZ023.
MARINE...STORM WARNING FOR PKZ042-043.
         GALE WARNING FOR PKZ021-022-041-051-052.
         SMALL CRAFT ADVISORY FOR PKZ033>036.
         SMALL CRAFT ADVISORY DUE TO SEAS FOR PKZ053.

&&

RWT/JBT