Gale Warning 145, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
338 PM AKST SAT FEB 11 2012

.SHORT TERM...AN OCCLUDED FRONT STRETCHED ACROSS THE NORTHERN
GULF THEN SOUTH THROUGH THE COASTAL WATERS WILL PUSH ACROSS
SOUTHEAST ALASKA TONIGHT. A DEVELOPING LOW ALONG THE FRONT IN THE
SOUTHEAST GULF DEEPENS TO AROUND 990 MB AS IT MOVES NORTH THIS
EVENING THEN CURVES NW TOWARDS PRINCE WILLIAM SOUND AND WEAKENS
LATE TONIGHT. A RIDGE OF HIGH PRESSURE BUILDS NORTH ACROSS THE
EASTERN GULF AND SOUTHEAST ALASKA ON SUNDAY.

 CURRENTLY HAVE GALES THAT ARE DIMINISHING THROUGH THE COASTAL
WATERS AND GO TO SMCR THIS EVENING. SE WINDS JUST STARTING TO
PICK UP THROUGH THE INNER CHANNELS THIS AFTERNOON AND REACH
20-25 KT TONIGHT. DO HAVE STRONG WIND HEADLINE FOR ZONE 27 THIS
EVENING.

 RAIN HAS REACHED THE COAST AND WILL SPREAD ACROSS ALL SE BY LATE
EVENING. WILL START OUT THE FAR NORTH WITH SNOW OR MIXED RAIN
SNOW DUE TO WET BULB EFFECT. COULD SEE UP TO 3 INCHES INLAND AND
HIGHER ELEVATIONS ALONG THE HIGHWAYS.

 FRONT IS OUT OF THE AREA BY MORNING WITH SHOWERS SPREADING IN
FROM THE SW ON SUNDAY. THERE IS CAA IN LOWER LEVELS AND HAVE
NORTHERN HALF MIXED THROUGH THE DAY BUT ACCUMS WILL BE AN INCH OR
LESS EXCEPT FOR PAYA AREA WHICH COULD SEE UP TO 3 INCHES SUNDAY.
SMCR SLYS FOR LYNN CANAL WITH THE PUSH.

 GOOD MODEL AGREEMENT THIS MORNING. LIKE UKMET SURFACE PRES BEST
WHICH CLOSED OFF DEVELOPING LOW IN COASTAL WATERS.

.LONG TERM...THERE HAS NOT BEEN MUCH CHANGE IN THE FORECAST MODELS
THROUGH MOST OF NEXT WEEK...SO THERE IS STILL SIGNIFICANT AMOUNT
OF DIFFERENCES WITH TRACKS OF FRONTS MOVING ACROSS THE GULF. THE
OVERALL UPPER LEVEL PATTERN IS IN FAIR AGREEMENT BUT THE AT THE
SURFACE THERE IS DIFFERENCES WITH THE DETAILS AT THE SURFACE. SO
THERE WAS NOT MUCH CHANGE FROM PREVIOUS FORECAST IN THE MID RANGE
AND REFRESHED THE EXTEND PORTION OF THE FORECAST WITH THE LATEST
HPC GUIDANCE. THE BIGGEST CHANGE FROM PREVIOUS FORECAST WAS TO
SLOW DOWN THE EASTWARD PROGRESSION OF A STALLED WEATHER FRONT OVER
THE GULF MON/TUE. THE MAIN REASON FOR THIS WAS THAT THERE WAS NO
FEATURE THAT WOULD PUSH THE FRONT EAST UNTIL A SHORTWAVE TROF
DRIFTS ACROSS THE GULF LIFTS OVER SE AK TUE AFTERNOON/NIGHT.

AT THE START OF THE LONG PERIOD A UPPER TROF WILL BE OVER SE AK
WITH A RIDGE BUILD OVER THE GULF. THIS TROF WILL KEEP A MIX OF
RAIN OR SNOW SHOWERS LIKELY TO SCATTERED OVER AREA BUT AS THE
RIDGE MOVES OVER THE FORECAST AREA THE SHOWERS WILL SLOWLY
DIMINISH OVER THE SOUTHERN HALF BY EARLY MON MORNING. A SURFACE
RIDGE WILL BUILD OVER THE INNER CHANNELS THROUGH SUN NIGHT AND
KEEP SOUTHERLY WINDS FROM 15 TO 25 KT WITH THE STRONGEST WINDS
OVER NORTHERN LYNN. THESE WINDS WILL PERSIST INTO MON MORNING AS
THE RIDGE WILL PERSIST BUT DECREASE THROUGH THE AFTERNOON AS THE
RIDGE WEAKENS. THERE WILL ALSO BE SOME GUSTY WINDS OVER LAND BUT
THEY WILL DISSIPATE BY MON MORNING AS THE PRESSURE GRADIENT
RELAXES.

FOR THE REST OF MON AND TUE...A FRONT WILL MOVE ACROSS THE GULF
WITH GOOD ONSHORE FLOW FROM THE SOUTH AS THE UPPER RIDGE DRIFTS
OVER THE PANHANDLE AND A NEGATIVELY TILTED UPPER TROF EXTENDS FROM
THE AK PENN SE INTO THE NORTH PACIFIC. A FRONT WILL FORM OVER THE
WESTERN GULF LATE SUN NIGHT AND DRIFT EAST TO BE OVER THE NORTH
AND CENTRAL GULF. THIS FRONT WILL THEN SLOW DOWN AND STALL OVER
THE CENTRAL GULF WITH STRONG ONSHORE FLOW RIGHT INTO PAYA. SO
THERE WILL BE CAT PRECIP FOR THE NORTHERN GULF AREAS WITH SOME
PRECIP BEING HEAVY AT TIMES. FOR THE MOST PART THE PRECIP WILL BE
IN THE LIQUID FORM BUT THERE MAY BE A CHANCE FOR SOME FROZEN
PRECIP AT NIGHT WITH WINDS FROM THE EAST. THE INNER CHANNELS WILL
BE ON THE DRY SIDE FOR THE MOST PART WITH UPPER HIGH RIGHT OVER
THE PANHANDLE WITH WEAK SE FLOW AT THE MID-LEVELS. A CHANCE OF
PRECIP WILL REMAIN FOR THE NORTHERN HALF OF THE AREA MONDAY
MORNING BUT FOR THE MOST PART BE DRY UNTIL THE UPPER TROF LIFTS
OVER THE PANHANDLE TUE EVENING AND LIFTS THE FRONT OVER THE AREA.

FORECASTER CONFIDENCE IS BELOW AVERAGE THROUGH THE MID RANGE WITH
BELOW AVERAGE FOR THE EXTEND PERIODS. WHERE CHANGES TO THE FORECAST
WAS MADE USED A BLEND OF THE 12Z EC THROUGH DAY 3 THEN HPC FOR
DAY 5-7.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...STRONG WIND UNTIL 9 PM AKST THIS EVENING FOR AKZ027.
         STRONG WIND UNTIL 6 PM AKST THIS EVENING FOR AKZ022.
         STRONG WIND UNTIL 6 PM AKST THIS EVENING FOR AKZ023.
MARINE...GALE WARNING FOR PKZ041>043-051-052.
         SMALL CRAFT ADVISORY FOR PKZ011-012-021-022-031>036-053.

&&

MM/ABJ