Small Craft Advisory 15, NWS Anchorage, AK

AREA FORECAST DISCUSSION SOUTHWEST ALASKA
500 AM AST WED JAN 5 2005

.DISCUSSION...

MAIN FEATURES AT 500 MB ARE A STRONG HIGH CENTERED NEAR 50N 140W AND
A SECOND HIGH CENTERED NEAR 47N 179W. A COL AREA IS SOUTH OF THE
SOUTHERN END OF THE ALASKA PENINSULA BETWEEN THE TWO HIGH CENTERS. A
RELATIVELY WEAK TROUGH IS CROSSING INTO THE WESTERN GULF OF ALASKA.
AN EVEN WEAKER TROUGH IS CROSSING FROM THE EASTERN BERING TO NORTON
SOUND. ON THE SURFACE...A WEAK FRONT ASSOCIATED WITH THE STRONGER OF
THE TWO TROUGHS IS CROSSING THE WESTERN GULF OF ALASKA. THE WEAKER
UPPER TROUGH IS ASSOCIATED WITH A 1007 MB LOW IN THE BERING STRAITS
WITH A WEAK FRONT EXTENDING SOUTH TO NEAR NUNIVAK ISLAND. GOES IR
LOOP INDICATES THAT SYSTEM APPROACHING NORTON SOUND MOVING RAPIDLY
INTO THE NORTHERN INTERIOR. UPPER CLOUD SHIELD ASSOCIATED WITH
ANOTHER SYSTEM WELL TO THE WEST OF THE BERING SEA VISIBLE SPILLING
OVER RIDGE AXIS NEAR THE DATELINE. CONSIDERABLE STRATOCUMULUS OVER
MUCH OF THE BERING SEA.

COMPARISON OF GFS AND MESOETA...BOTH MODELS APPEAR TO INITIALIZE THE
TWO HIGHS AND THE TROUGH IN ABOUT THE SAME PLACE AND WITH THE SAME
CENTRAL VALUES. NO MAJOR DIFFERENCES BETWEEN THE TWO MODELS THROUGH
SATURDAY. GFS AND MESOETA DEVELOP A SINGLE VERY STRONG 500 MB HIGH
CENTERED ON THE ALASKA PENINSULA BY EARLY THURSDAY. GFS TAKES 500 MB
HIGH CENTER SLIGHTLY FURTHER NORTH THAN MESOETA ON FRIDAY THEN
SOMEWHAT FURTHER SOUTH THAN MESOETA ON SATURDAY. ON SURFACE...MESOETA
A FEW MILLIBARS STRONGER ON CENTRAL VALUE OF HIGH. BOTH MODELS
INDICATE NEXT SYSTEM WILL APPROACH BERING SEA FROM THE SOUTHWEST
SATURDAY. GFS SOMEWHAT DEEPER ON PROJECTED CENTRAL PRESSURE OF THIS
LOW AT 985 MB THAN MESOETA AND ABOUT 991 MB.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORMS 13B.
         GALES WESTERN GULF OF ALASKA BERING SEA 8 12A 12B 13A 14.
FIRE WEATHER...NONE.

STM JAN 05