Snow Advisory 6, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
300 PM AST SAT JAN 20 2007

.DISCUSSION...A LARGE 960 MB LOW IS IN THE CENTRAL GULF OF ALASKA
THIS AFTERNOON AND IS BEARING DOWN ON THE NORTH GULF COAST. THIS LOW
WILL HEAD JUST EAST OF CORDOVA OVERNIGHT AND THEN RAPIDLY WEAKEN AS
IT PUNCHES INTO THE EASTERN COPPER RIVER BASIN SUNDAY MORNING. A WEAK
SECONDARY LOW IS THEN EXPECTED TO FORM IN PRINCE WILLIAM SOUND SUNDAY
MORNING.

THE LOW IN THE GULF TODAY HAS PROMPTED A BLIZZARD WARNING FOR KODIAK
ISLAND. AREAS OF SNOW AND BLOWING SNOW ARE ALSO OCCURRING IN THE
EASTERN KENAI PENINSULA.

IN THE UPPER LEVELS THE COLD TROUGH THAT HAS BEEN ENTRENCHED OVER THE
EASTERN BERING SEA WILL MOVE SLOWLY EASTWARD THROUGH EARLY NEXT WEEK.

IT WILL MAKE IN TO CENTRAL ALASKA AND THEN DISSIPATE MONDAY AS A NEW
TROUGH DROPS DOWN OUT OF THE CHUKCHI SEA AND TAKES UP RESIDENCE IN
THE EASTERN BERING SEA BY WEDNESDAY.

THE WEAK LOW NEAR NUNIVAK ISLAND WILL PERSIST FOR ANOTHER DAY OR SO
AND IT DRIFTS TO NEAR CAPE NEWENHAM SUNDAY. IT WILL FINALLY DISSIPATE
BY MONDAY MORNING AS A RIDGE OF HIGH PRESSURE IN THE CENTRAL BERING
SEA NUDGES EASTWARD EARLY NEXT WEEK.

IN THE LONGER TERM ANOTHER MODERATELY STRONG LOW WILL MOVE INTO THE
GULF OF ALASKA AROUND THE MIDDLE OF NEXT WEEK WHILE THE RIDGE IN THE
BERING SEA REMAINS RELATIVELY STATIONARY.

MODELS HAVE BEEN AND CONTINUE TO FLUCTUATE ON THE EXACT TRACK ON THE
LOWS THAT MOVE INTO THE GULF FROM THE SOUTH. TODAYS LOW IS NO
DIFFERENT WITH THE NAM BRINGING THE LOW A BIT FURTHER EAST THAN THE
GFS OR THE UKMET. PREFER THE GFS AND UKMET TRACK TO THE NAM.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING 171.
MARINE...STORM 120. GALE 121 130 132 138.
         HEAVY FREEZING SPRAY 179 185.
FIRE WEATHER...NONE.

JAN 07