Gale Warning 303, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
400 PM AKDT TUE MAR 17 2009

.MODEL DISCUSSION...MODELS ARE IN GOOD AGREEMENT WITH EACH OTHER AND
LOOK GOOD IN THE WEST. IN THE GULF OF ALASKA AREA THERE IS CONCERN
WITH ALL THE MODELS. IN THE BROAD GULF LOW THERE ARE TOO MANY LOW
VORTEXES FOR THE MODELS TO DETECT AND ADEQUATELY RESOLVE.

.ANALYSIS/UPPER LEVELS AND SHORT TERM FORECAST...AN UPPER LEVEL
TROUGH CONTINUES TO EXTEND OVER THE MAINLAND PART OF THE STATE WITH A
SHARP UPPER LEVEL RIDGE OVER THE WESTERN BRING SEA INTO EASTERN
RUSSIA. THE OVERALL UPPER LEVEL PATTERN WILL NOT CHANGE MUCH THROUGH
MOST OF THE WEEK.
THE BIGGEST SURFACE FEATURE IS THE BROAD COMPLEX LOW IN THE GULF OF
ALASKA. THE COMPLEXITY OF THIS FEATURE IS BEST SEEN OF THE VISIBLE
SATELLITE LOOP. THERE ARE AT LEAST FIVE SEPARATE VORTEXES IN THE
VICINITY OF THE GULF THAT ARE EACH BRINGING GUSTY WINDS AND MODERATE
SNOW SHOWERS. THERE IS ALSO SIGNIFICANT CLEARING BETWEEN THESE
VORTEXES CAUSING A LARGE SWING IN WEATHER FROM BEING CLEAR TO LOW
VISIBILITIES IN SNOW AND BLOWING SNOW IN THE GULF REGION. KODIAK
ISLAND IS TAKING THE BRUNT OF THIS WITH THE LOWS MOSTLY TRACKING OVER
THE ISLAND.
GUSTY NORTHERLY WINDS OVER THE EASTERN BERING SEA AND ALASKA
PENINSULA WILL PERSIST FOR MOST OF THE WEEK.

.LONG TERM FORECAST...NOT MUCH CHANGE IN THE LONG WAVE PATTERN
THROUGH THE WEEKEND. YESTERDAYS MODEL RUNS HINTED AT THE BLOCKING
RIDGE OVER EASTERN RUSSIA AND THE BERING SEA BEING BROKEN DOWN BY
LATE IN THE WEEKEND...BUT THAT DOES NOT LOOK AS LIKELY TODAY.
THEREFORE THERE WILL BE LITTLE CHANGE IN THE OVERALL WEATHER WITH
COLDER TEMPERATURES PERSISTING OVER MOST OF THE AREA WITH SNOW
SHOWERS AROUND THE GULF OF ALASKA AND GUSTY WINDS IN THE EASTERN
BERING SEA AND SOUTHWEST ALASKA INCLUDING THE ALASKA PENINSULA.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 150 155
         HEAVY FREEZING SPRAY 130 132 138 140 150 155 160 165 170 171
                              179 185.
FIRE WEATHER...NONE.

MAR 09