Snow Advisory 11, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM AST TUE MAR 6 2007

.DISCUSSION...

LARGE SCALE...THE MOST SIGNIFICANT FEATURE IS THE CONTINUED DOMINANCE
OF THE MID PACIFIC RIDGE FOR THE FORECAST AREA. THIS FEATURE IS
ALMOST UNPRECEDENTED AT LEAST OVER THE PAST 20 YEARS...AND SHOWS NO
SIGN OF BREAKING DOWN OVER THE NEXT WEEK. IF THAT VERIFIES IT WOULD
MEAN THE RIDGE HAS BEEN QUASISTATIONARY FOR ALMOST A MONTH WITH A
GENERAL COLD NORTHWEST FLOW OVER ALL BUT THE WESTERN ALEUTIANS. IF
THE FLOW EVOLVES AS CURRENTLY FORECAST THE ICE EDGE WILL CLOSE IN ON
THE PRIBILOFS OVER THE WEEKEND AND THROUGH MOST OF BRISTOL BAY AND
THE EASTERN BERING SEA.

IN THE SHORT TERM...MODELS ARE SLOW DEVELOPING PRECIPITATION ACROSS
THE COASTAL REGIONS OF SOUTH CENTRAL ALASKA. FAIRLY SIGNIFICANT
VERTICAL MOTION FIELD IN MID LEVEL DIFLUENT FLOW WILL MOVE ACROSS
COOK INLET OVER THE NEXT 24 HOURS IS DECEIVING. LOW PRECIPITABLE
WATER LIKELY THE CULPRIT. HOWEVER...EXPECT SNOW TO SPREAD INTO
ANCHORAGE BOWL ON WEDNESDAY AS DEEP COLD ARCTIC AIR WILL DIMINISH THE
NORMAL DOWNSLOPE. SOUTHCENTRAL IS ON THE EDGE OF A FAIRLY SIGNIFICANT
SNOWFALL THOUGH WATER TO SNOW RATIOS WILL BE 20 TO 1. REGARDLESS OF
THE AMOUNTS THE SNOWFALL IS ESPECIALLY SIGNIFICANT IN LIGHT OF THE
CLEAR SKIES THAT HAVE PREVAILED FOR ALMOST 2 WEEKS. WILL ISSUE A SNOW
ADVISORY FOR WEDNESDAY MORNING THROUGH THURSDAY MORNING.

MOST SIGNIFICANT WEATHER WILL ALMOST CERTAINLY OCCUR ON KODIAK ISLAND
WHERE SNOW...STRONG WINDS..AND BLOWING SNOW WILL RESULT IN BLIZZARD
CONDITIONS WEDNESDAY EVENING THROUGH THURSDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...STORM 150.
         GALE 155 160 165 170 120 121 125 129 130 132 138.
         HEAVY FREEZING SPRAY 150 160 165 120 121 125
                              129 130 132 138 140 141.
MARINE...
FIRE WEATHER...NONE.

CAS MAR 07