Gale Warning 1, NWS Juneau, AK

SOUTHEAST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JUNEAU AK
306 PM AKST SAT JAN 1 2011

.SHORT TERM...THE LATEST SATELLITE IMAGERY SHOWS THE PANHANDLE
UNDER CLOUDY SKIES WITH A WEATHER FRONT OVER THE CENTRAL GULF.
MOST STATIONS OVER THE INNER CHANNELS ARE REPORTING PERIODS OF
LIGHT RAIN OR DRIZZLE WITH VERY STABLE ATMOSPHERIC CONDITIONS.
THE NORTHER GULF IS REPORTING MORE STEADY RAIN WITH STRONGER
UPPER LEVEL DYNAMICS AND ONSHORE FLOW. WINDS ACROSS THE AREA ARE
ON THE LIGHT SIDE WITH SOME MIN SMALL CRAFT WINDS IN NORTHERN
LYNN AND CLARENCE STRAIT. OVER THE GULF WINDS ARE GENERALLY 20 TO
25 KT BUT WITH THE APPROACHING WEATHER FRONT FROM THE WEST WINDS
WILL INCREASE TO 30 KT OVER THE CENTRAL AND NORTHERN GULF LATE
TONIGHT.

THE UPPER RIDGE THAT IS OVER THE EASTERN GULF AND PANHANDLE THIS
AFTERNOON WILL SLOWLY DRIFT TO THE EAST THROUGH TONIGHT TO BE OVER
CANADA BY SUNDAY MORNING. THE RIDGE IS BEING PUSHED TO THE EAST BY
AN STRONG UPPER TROF CURRENTLY OVER THE WESTERN GULF. THIS FEATURE
WILL DRIFT EAST THROUGH THE NEXT 24 HOURS TO BE OVER THE EASTERN
GULF BY SUN AFTERNOON. AT THE SURFACE THE RIDGE OF HIGH PRESSURE
OVER THE PANHANDLE WILL SLOWLY WEAKEN THROUGH TONIGHT AND SLIDE
EAST AS WEAK SURFACE TROF MOVES OVER THE EASTERN GULF BY SUN
AFTERNOON.

SO FOR TONIGHT...THE PANHANDLE WILL CONTINUE TO SEE LOW CLOUDS
AREAS OF FOG ALONG WITH PERIOD OF LIGHT RAIN OR DRIZZLE AS THE LOW
BOUNDARY LAYER WILL REMAIN BE VERY STABLE. THERE IS ALSO MODERATE
ONSHORE FLOW TO KEEP A GOOD SOURCE OF MOISTURE MOVING OVER THE SE
AK. WINDS WILL SLOWLY DIMINISH OVER LAND AND MOST MARINE WATERS
WILL SEE THE WINDS RANGING FROM 10 TO 15 KT. OVER THE EASTERN GULF
WINDS WILL REMAIN NEAR 20 KT BUT AS THE TROF MOVES OVER THE GULF
WINDS OVER THE NORTH GULF WILL INCREASE TO 30 KT.

THERE WILL NOT BE MUCH CHANGE THROUGH SUNDAY AFTERNOON BUT THERE
MAY BE MORE STEADY RAIN OVER THE NORTHERN HALF OF THE PANHANDLE AS
THE UPPER TROF LIFTS OVER THE AREAS. THIS TROF IS ALSO EXPECTED TO
MIX THE LOWER ATMOSPHERE SOME AND LIFT THE CLOUDS AND AREAS OF
FOG. THE WINDS OVER THE GULF WILL SLOWLY DIMINISH TO RANGE FROM 20
TO 10 KT WITH THE STRONGEST WINDS OVER THE NORTHERN GULF AS THE
SURFACE TROF WEAKENS OVER THE EASTERN GULF.

.LONG TERM...THE WET CONDITIONS AND WARMER WINTER TEMPERATURES
CONTINUE THROUGH THE MIDDLE OF NEXT WEEK BEFORE A RETURN TO THE
COLD AND DRIER CONDITIONS OF DECEMBER. THE MORE PROGRESSIVE MID
LEVEL PATTERN STAYS IN PLACE THROUGH WEDNESDAY WITH PERSISTENT
SOUTHWEST MID LEVEL FLOW AND GALE FORCE FRONTS MOVING INTO THE
GULF AND ADVECTING ACROSS THE PANHANDLE. BY THURSDAY A STRONG MID
LEVEL RIDGE WILL DEVELOP IN THE WESTERN GULF AND SLOWLY RETROGRADE
OVER THE ALASKA PENINSULA BY EARLY NEXT WEEKEND. THIS BLOCKING
FLOW WILL ALLOW FOR A STRONG SURFACE HIGH TO DEVELOP IN THE YUKON
ALLOW FOR NORTHERLY OUTFLOW CONDITIONS ACROSS THE PANHANDLE AND
COLDER TEMPERATURES. THE 12Z MODELS HAVE COME INTO BETTER
ALIGNMENT WITH THE DEVELOPING BLOCKING PATTERN TOWARD THE END OF
NEXT WEEK WITH CONSIDERABLE AGREEMENT ON THE 12Z NAEFS...GFS AND
ECMWF ENSEMBLES AT MID LEVELS. THE OPERATIONAL 12Z ECMWF HAS ALSO
DEVELOPED THE BLOCKING RIDGE IN THE WESTERN GULF FURTHER WEST THAN
THE 12Z GFS AND MORE IN LINE WITH THE ENSEMBLE SOLUTIONS AND SO THE
12Z ECMWF SOLUTION WAS PREFERRED DAY 4 ONWARD COMBINED WITH THE
HPC SOLUTION. DAY 2 TO 4 THE 12Z ECMWF AGAIN INITIALIZED THE
PROGRESSIVE PATTERN THE BEST...AS THE 12Z OPERATIONAL GFS
CONSIDERABLY OVER PHASED THE MID LEVEL SOLUTION OF GALE FORCE
FRONTS MOVING INTO THE GULF SUNDAY NIGHT AND TUESDAY MORNING.
BLENDED INHERITED GRIDS TOWARD THE 12Z ECMWF SOLUTION THROUGH
TUESDAY AND THEN TOWARD THE HPC SOLUTION AFTERWARD.

EARLY MONDAY MORNING A GALE FORCE FRONT WILL MOVE INTO THE EASTERN
GULF BRINGING WINDY CONDITIONS TO THE OUTER COAST AND LOCALLY
HEAVY RAINFALL NEAR YAKUTAT. ATTM...THE 850 MB WINDS ARE NEAR 40
KNOTS WHICH TRANSLATES TO BELOW ADVY GUSTS HOWEVER WILL HAVE TO
MONITOR FUTURE MODEL RUNS IN CASE THE 850 MB LLJ IS STRONGER THAN
CURRENTLY FORECAST. MONDAY AFTERNOON A SURFACE TRIPLE POINT LOW MOVES
FROM THE NORTHEASTERN GULF INTO THE YUKON AND THIS WILL ALLOW THE
LOCALLY WINDY CONDITIONS MOVE INTO THE CENTRAL INNER CHANNELS WITH
NEAR SMCR LEVEL WINDS FROM FREDERICK SOUND NORTHWARD MONDAY
AFTERNOON AND EVENING. SEVERAL MORE NEAR GALE FORCE FRONTS MOVE
ACROSS THE PANHANDLE THROUGH WEDNESDAY IN THE SOUTHWESTERLY MID
LEVEL FLOW BRINGING LOCALLY WINDY CONDITIONS AND LOCALLY HEAVY
RAINFALL TO THE OUTER COAST. ATTM TIMING THESE FRONTAL BOUNDARIES
IS DIFFICULT GIVEN THE PROGRESSIVE MID LEVEL FLOW. SNOW LEVELS
WILL CONTINUE TO BE NEAR 1500 FEET AND ABOVE THROUGH WEDNESDAY
WITH 850 MB TEMPERATURES AT -3 C OR ABOVE AND THIS WILL KEEP SNOW
LIMITED TO THE NORTHERN ROADWAYS. WILL HAVE TO MONITOR THE CENTRAL
AND SOUTHERN PANHANDLE FOR LOCALIZED FLOODING DUE TO RECENT WARM
UP AND MELTING OF THE SURFACE SNOW PACK AND THE FORECAST OF HEAVY
RAINFALL FOR THE EARLY PART OF THE WEEK.

BY THURSDAY THE MID LEVEL PATTERN ACROSS THE PANHANDLE BEGINS TO
SHIFT AS A BLOCKING MID LEVEL RIDGE BUILDS INTO THE WESTERN GULF.
THIS WILL LEAD TO OFFSHORE FLOW WITH LOCALLY BREEZY CONDITIONS
NEAR INTERIOR PASSES TOWARD NEXT WEEKEND. NORTHERLY CAA AT 850 MB
DROPS SOUTHWARD INTO THE EASTERN GULF BY NEXT SATURDAY AND THIS
BRINGS 850 MB TEMPS TO NEAR -10 C AND THIS WILL ALLOW SNOW LEVELS
TO DROP TO THE SURFACE THROUGHOUT THE PANHANDLE.

FORECAST CONFIDENCE IS ABOVE AVERAGE THROUGH THE LONG TERM PERIOD
WITH THE WET WARM PATTERN BECOME COLDER AND DRY BY NEXT WEEKEND AS
ENSEMBLE SUPPORT AND PREDICTABILITY PARAMETERS ARE QUITE
FAVORABLE. TIMING THE INDIVIDUAL GALE FORCE FRONTS MOVING INTO THE
EASTERN GULF THROUGH WEDNESDAY WILL REMAIN DIFFICULT DUE TO THE
PROGRESSIVE MID LEVEL FLOW...HOWEVER EXPECT ABOVE NORMAL
TEMPERATURES AND PRECIP THROUGH WEDNESDAY FROM FREDERICK SOUND
NORTHWARD.

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...SMALL CRAFT ADVISORY FOR PKZ012-036-041>043-051-052.

&&

ABJ/PSS