Small Craft Advisory 213, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
254 PM AKST SUN MAR 6 2011

.SHORT TERM...SATELLITE IMAGES THIS AFTERNOON ARE SHOWING A
LINGERING WEAKENING LOW IN THE SW GULF. THE ASSOCIATED WEAK FRONT
EXTENDS ACROSS THE NORTHERN AND EASTERN GULF. THE PANHANDLE ITSELF
IS ENJOYING MOSTLY CLEAR SKIES WITH THE EXCEPTION OF THE SOUTHERN
OUTER COAST WHERE PARTLY TO MOSTLY CLOUDY SKIES EXIST. WINDS OVER
THE AREAS HAVE ALSO BEEN SOMEWHAT SUBDUED. THE EXCEPTION TO THAT
IS SKAGWAY WHERE A WIND ADVISORY IS STILL UP UNTIL 4 PM THIS
AFTERNOON DUE TO NORTH WINDS GUSTING TO 45 MPH. THIS MORNING'S SAR
PASS AT 15Z ALSO SHOWED SOME 30 TO 35 KT WINDS COMING OUT OF TAKU
INLET AS WELL.

 FOR TONIGHT AND TOMORROW, THE LOW IN THE GULF WILL CONTINUE TO
BE NEARLY STATIONARY AND CONTINUE TO WEAKEN. THE FRONT JUST
OFFSHORE OF THE OUTER COAST WILL REMAIN THERE AND GRADUALLY
WEAKEN AS WELL INTO TOMORROW. THE SOUTHERN PART OF THE FRONT MAY
GET JUST ENOUGH EASTWARD MOVEMENT TO BRING SOME PRECIP TO THE
SOUTHERN OUTER COAST SO HAVE CHANCE POPS THERE THROUGH TOMORROW.

 WINDS SHOULD BE SMALL CRAFT INTENSITY OR LESS OVER MOST OF THE
AREA BUT THE LINGERING PRESSURE GRADIENT ALONG THE COAST
MOUNTAINS MAY CONTRIBUTE TO SOME HIGHER WINDS NEAR SKAGWAY, LYNN
CANAL, AND TAKU INLET INTO TOMORROW.

 TEMPS WILL ALSO REMAIN COOL FOR LOWS AS RADIATIONAL COOLING
TAKES OVER AT NIGHT BUT THE STRENGTHENING SUN WILL WARM TEMPS
BACK UP INTO THE MID 30S TO LOW 40S TOMORROW.

 MODELS WERE IN GOOD AGREEMENT FOR THE SHORT RANGE PERIOD.
DECIDED TO USE THE NAM FOR ITS GOOD INITIALIZATION AND DETAILS.
FORECAST CONFIDENCE IS ABOVE AVERAGE.

.LONG TERM... SEMI PERMANENT WEATHER PATTERN IS FORECAST TO HOLD
THROUGH MUCH OF THE EXTENDED PERIOD. THE PAST SEVERAL INDIVIDUAL
LARGE SCALE MODEL RUNS ARE PRETTY CONSISTENT IN THEIR RESPECTIVE
PATTERN EVOLUTION DURING THE WEEK AHEAD. MODEL DIAGNOSTIC
DISCUSSIONS FROM PREVIOUS FORECASTS AND NATIONAL CENTER CONTINUE
TO FAVOR THE SOLUTIONS FROM THE NAM THROUGH TUE THEN TRANSITION TO
LONG RANGE ECMWF AND ECMWF ENSEMBLE MEAN DUE TO ITS RELUCTANCE TO
BREAK DOWN BLOCKING PATTERN OVER AK.

UPPER LEVEL 500 MB HIGH PRESSURE IS CENTERED JUST NW OF AK TODAY
AND ITS ELONGATED RIDGE AXIS EXTENDS S ALONG OR JUST EAST OF THE
DATELINE. STRONG WLY JET STREAM LEVEL WINDS SPLIT IN HALF RIGHT
AROUND 30N 180W. THE NORTHERN BRANCH LOOPS AROUND THE STATE AND
INTO NORTHERN CANADA. THE SOUTHERN BRANCH TAKES AIM ON THE PAC NW
FOR THE WEEK AHEAD. WITH ONLY VERY WEAK STEERING FLOW REMAINING ALOFT
AK I DO NOT SEE ANY MAJOR STORM ACTIVITY APPROACHING SE AK FOR NEXT
4-5 DAYS.

LOW PRESSURE SFC/ALF IS SORT OF TRAPPED IN THE GULF AND WILL
WOBBLE AROUND THROUGH ABOUT WED WITH VERY LITTLE EFFECT ON
PANHANDLE. MODEL GUIDANCE SUGGESTS ASSOCIATED FRONTAL CLOUD BANDS
EXTENDING SE FROM THE LOW CENTER WILL EDGE CLOSER TO THE COAST. AS
THE WEAK FRONTS APPROACH THE COAST THE PRESSURE GRADIENTS BETWEEN
PERSISTENT HIGHER PRESSURE INLAND WILL TIGHTEN UP AGAIN AND KEEP
LOCALLY WINDY CONDITIONS GOING...ESP THROUGH GAPS FROM THE N AND E.

BEST CHCS FOR LIGHT PCPN ARE OVER THE SRN HALF OF PANHANDLE TUE-
WED AND AGAIN NEAR THE WEEKEND. THE NORTHERN HALF OF PANHANDLE IS
EXPECTED TO REMAIN DRY BUT WITH INCREASING CLOUDS OVER TIME.
GRIDDED FORECASTS WERE REFRESHED USING A BLEND OF THE NAM FOR ON
NIGHT AND TUES THEN EURO MODEL...NATIONAL CENTER GUIDANCE FOR
AK...AND THE GFS FOR LONGER RANGE. FORECAST CONFIDENCE IF AT OR ABOVE
AVE.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...WIND ADVISORY UNTIL 4 PM AKST THIS AFTERNOON FOR AKZ018.
MARINE...GALE WARNING FOR PKZ012-043.
         SMALL CRAFT ADVISORY FOR PKZ011-013-021-022-031>033-035-041-042-
     051-052.

&&

EAL/TA