Small Craft Advisory 20, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
300 PM AKST THU JAN 7 2010

.MODEL DISCUSSION...MODELS SEEM TO HAVE INITIALIZED A LITTLE BETTER
THAN PREVIOUS RUNS AND BOTH THE NAM AND GFS HAVE DETECTED THE MESO
LOW NEAR THE SOUTHERN PART OF KODIAK ISLAND. MODELS ALL AGREE NOW ON
THE MOVEMENT OF THE LOW IN THE SOUTHEASTERN GULF THAT WILL ROTATE
SOUTH OF MIDDLETON ISLAND TOMORROW AS WELL. IN THE LONGER TERM THE
ECMWF IS COMING IN LINE WITH THE GFS IN STRENGTHENING A LOW INTO THE
950 MB RANGE SOUTH OF KODIAK ISLAND OVER THE WEEKEND.

.ANALYSIS AND UPPER LEVELS...AN UPPER LEVEL HIGH CENTERED NEAR THE
BERING STRAIT EXTENDS IT RIDGE EASTWARD OVER THE INTERIOR OF THE
STATE. A LOW SOUTH OF KODIAK ISLAND WILL MOVE EASTWARD THROUGH
TOMORROW BUT BE REPLACED BY ANOTHER LOW AFTER THAT AS THESE LOWS ARE
SEATED IN THE UPPER LEFT EXIT REGION OF THE JET STREAM WHICH IS A
FAVORABLE PLACE FOR LOW FORMATION.

.SHORT TERM FORECAST...A SHORT WAVE IS VISIBLE ON SATELLITE IMAGERY
NEAR THE KODIAK AREA WITH A WEAK CIRCULATION SOUTH OF THE ISLAND.
THIS FEATURE WILL CONTINUE ITS WESTWARD MOVEMENT AND WEAKEN
SIGNIFICANTLY OVERNIGHT. WHILE THIS WAVE BROUGHT SOME RAIN TO THE
NORTH GULF COAST THE PRECIPITATION IS DIMINISHING AND MOSTLY
DISSIPATED IN THE DOWNSLOPE AS IT PASSED OVER THE MOUNTAINS.
KODIAK WILL TAKE A LITTLE LONGER TO GET OUT OF THE RAIN BUT IT SHOULD
DIMINISH SOME BY MORNING AND THEN JUST BE SHOWERS BY TOMORROW.
SOUTHWEST ALASKA AND BRISTOL BAY ARE STILL UNDER THE INFLUENCE OF
HIGH PRESSURE. WHILE THE BRISTOL BAY REGION WILL SEE SOME INCREASE IN
CLOUDINESS WITH THE SHORT WAVE MOVING THROUGH BUT THE PRECIPITATION
SHOULD NOT MAKE IT MUCH PAST THE ALEUTIAN RANGE.

.LONG TERM FORECAST...
OVER THE WEEKEND THE UPPER LEVEL HIGH IS EXPECTED TO SHIFT NORTHWARD
ALLOWING THE CUT OFF LOW TO DO SO AS WELL.  THIS WILL ALLOW THE
SURFACE LOWS TO MAKE IT INTO THE GULF OF ALASKA WHICH WILL BRING MORE
WEATHER TO THE GULF COAST. BY EARLY NEXT WEEK THE UPPER LEVEL LOW
WILL MOVE INTO THE GULF OF ALASKA AND STORMY WEATHER WILL RETURN TO
THE SOUTHERN THIRD OF THE MAINLAND.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 130.
         HEAVY FREEZING SPRAY 180 185.
FIRE WEATHER...NONE.

JAN 10