Gale Warning 381, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
123 PM AKST SAT NOV 26 2011

.SHORT TERM...SHORT RANGE FORECAST IS CURRENTLY IN A QUIET
PERIOD BETWEEN STORMS AT THE MOMENT. LAST NIGHTS SYSTEM IS
CURRENTLY EXITING THE PANHANDLE TO THE EAST AND TAKING MOST OF
THE PRECIP WITH IT. OVERNIGHT SNOWFALL AMOUNTS INCLUDE 5 INCHES
IN DOWNTOWN JUNEAU, 10 INCHES IN HAINES, 5.5 INCHES AT PETERSBURG
AND SITKA, WITH LESSER AMOUNTS AROUND THE AREA. LAST HOLD OUT FOR
SNOW IS IN THE EXTREME SE PART OF THE PANHANDLE WHERE SOME
HEAVIER SNOW MAY STILL BE OCCURRING IN ZONE 29. THERE WAS ALSO
SOME HIGHER WINDS IN THE SOUTHERN PANHANDLE AS THE LOW MOVE
THROUGH. GUSTS REACHED 52 MPH IN ANNETTE LATE LAST NIGHT. WINDS
HAVE CALMED DOWN THROUGH THE MORNING AS THE LOW WEAKENED AND
MOVED INLAND. ELSEWHERE WINDS ARE MOSTLY LIGHT AND SKIES ARE
OVERCAST TO PARTLY CLOUDY.

INTO TONIGHT AND TOMORROW, THE COLD WEATHER REMAINS WITH US AS A
COLD UPPER TROUGH MOVES THROUGH. ANY LINGERING SHOWERS WILL BE IN
THE FORM OF SNOW FOR MOST OF THE PANHANDLE AS 850 MB TEMPS AS LOW
AS -10 REACH ALL THE WAY TO THE SOUTHERN PANHANDLE BY TOMORROW.
SNOWFALL AMOUNTS SHOULD BE LIGHT BUT HEAVIER SHOWERS OF SNOW STILL
COULD DROP A FEW QUICK INCHES IN LOCALIZED AREAS. A BETTER CHANCE
FOR PRECIP WILL BE IN THE EXTREME SOUTHERN PANHANDLE AGAIN AS A
WEAKER LOW MOVES BY WELL TO THE SOUTH. THE VERY NORTHERN EDGE OF
THE PRECIP SHIELD MAY BRUSH THE SOUTHERN PARTS OF ZONES 28 AND 29
TONIGHT.

WINDS SHOULD NOT BE TOO MUCH OF A PROBLEM EITHER AS MOST STAY
BELOW 20 KT. THE EXCEPTION IS NORTHERN LYNN CANAL AND THE OFFSHORE
ZONE. FOR THE FORMER, THE NORTHERLY PRESSURE GRADIENT REMAINS IN
TACK AND EVEN INCREASES A BIT LATE TONIGHT. NORTHERLY WINDS TO 20
KT WITH SOME HIGHER GUSTS ARE POSSIBLE THERE LATER TONIGHT AND
INTO EARLY SUN. FOR THE LATTER, THE EXTREME SW PART WILL START TO
EXPERIENCE S TO SE WINDS TO 30 KT SUN AFTERNOON AS THE LEADING
EDGE OF THE APPROACHING FRONT MAKES ITSELF KNOWN.

SHORT RANGE MODELS WERE IN DECENT AGREEMENT BUT DID HAVE SOME
INITIALIZATION ISSUES WITH THIS MORNINGS LOW IN THE SOUTHERN
PANHANDLE. GFS WAS WAY TOO SLOW WITH THE PROGRESSION OF IT, AND
THE UPPER LEVEL FEATURES WERE NOT THAT WELL REPRESENTED. STILL
DECIDED TO STICK WITH THE NAM AND THE EC TODAY AS BOTH WERE NOT AS
BAD AS SOME OF THE OTHERS TODAY. FORECAST CONFIDENCE IS A LITTLE
ABOVE AVERAGE.

&&

.LONG TERM...EXPECT A SYNOPTIC CHANGE FROM A COOL TO WARM WEATHER
PATTERN BY MID WEEK AS A HIGH AMPLITUDE UPPER LEVEL RIDGE BUILDS
FROM THE CENTRAL PACIFIC TO NEAR VANCOUVER ISLAND WITH A LONG SW
FETCH OVER THE PANHANDLE.

WILL BEGIN THE LONG RANGE WITH A COLD POOL OVER THE PANHANDLE
SUNDAY NIGHT. A MODERATELY STRONG OCCLUDED FRONT PUSHES ACROSS THE
GULF SUNDAY NIGHT AND ACROSS SOUTHEAST ALASKA MONDAY WITH WAA
TAKING OVER. EXPECT AN INCLUSIVE CHANGE OVER FROM SNOW TO RAIN
BEGINNING ALONG THE COAST AND IN SOUTHERN SUNDAY NIGHT SPREADING NE
ACROSS SOUTHEAST ALASKA THROUGH TUESDAY. WILL LIKELY SEE ONE MORE
SIGNIFICANT SNOW EVENT FOR INNER CHANNELS ON SUNDAY NIGHT INTO
EARLY TUESDAY FOR THE FAR NORTH SOUTHEAST ALASKA. CONFIDENCE ON
TIMING AND INTENSITY IS LOW AND WILL NOT POST ANY WATCHES WITH
THIS AFTERNOONS ZONES BUT WILL HIGHLIGHT THE POTENTIAL FOR MORE
SNOW...ESPECIALLY NORTHERN INNER CHANNELS.

AS THIS FRONT MOVES TO THE EASTERN GULF EXPECT SOLID GALES TO
MOVE INTO COASTAL WATERS SUNDAY NIGHT AND PROBABLY SOUTHERN INNER
CHANNELS ON MONDAY. BEHIND THE FRONT, WIND WILL DIMINISH AND
SHIFT TO THE SW WHICH WILL PUSH WARMER AIR MASS INTO SOUTHEAST
ALASKA. THERE ARE SEVERAL WAVES ALONG THE TRAILING FRONT IN THE
NORTH PACIFIC THAT ARE ADVERTISED TO LIFT NE INTO GULF BUT AGAIN
TIMING, INTENSITY, AND LOCATIONS CONTINUE TO VARY FROM RUN TO RUN
WITH LOW CONFIDENCE ON DETAILS.

THERE IS A GENERAL AGREEMENT IN THE UPPER LEVELS FOR A HIGH
AMPLITUDE RIDGE TO BUILD NE WITH AXIS JUST SE OF PANHANDLE BY
WEDNESDAY. THIS WILL ALLOW A LONG AND MOIST FETCH OF MOISTURE INTO
THE PANHANDLE WITH POTENTIAL FOR HEAVY RAIN ON TOP OF SNOW IN WED
OR THUR TIME FRAME DEPENDING HOW FAST RIDGE SETS UP. BEYOND WED
MODELS DIVERGE SIGNIFICANTLY WITH ARE A VARIETY OF SOLUTIONS THAT
KEEP A HIGH AMPLITUDE RIDGE IN PLACE OR FLATTEN IT OUT ACROSS THE
GULF WITH MUCH HIGHER HEIGHTS ACROSS SOUTHEAST ALASKA. BOTH OF
THESE SOLUTIONS WOULD ALLOW FOR RELATIVELY WARMER TEMPERATURES WITH
RAIN AS PREDOMINANT PRECIPITATION TYPE.

WITH LOW CONFIDENCE AND MODEL TO MODEL AND RUN TO RUN CHANGES
STILL OCCURRING, OPTED TO MAKE NO CHANGES TO GRIDS AND WILL JUST
HIGHLIGHT THE SLOW TRANSITION FROM SNOW TO RAIN AT THIS TIME.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-041. SMALL CRAFT ADVISORY
DUE TO SEAS FOR PKZ042-043-051-052.

&&

EAL/MM