Small Craft Advisory 8, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTH CENTRAL AND SOUTHWEST ALASKA
200 PM AKST SAT JAN 2 2010

.MODEL DISCUSSION...
NUMERICAL GUIDANCE IN VERY GOOD AGREEMENT THROUGH 60 HOURS. AS
EXPECTED CERTAINTY AND TIMING OF EVENTS FOR DAYS 4 THROUGH 8 IS MORE
UNCERTAIN BUT THE SYNOPTIC PATTERN DEPICTED BY ALL MODELS IN IS GOOD
GENERAL AGREEMENT. HPC DAY 4-8 GUIDANCE LOOKS GOOD.

.ANALYSIS AND UPPER LEVELS...
AN WEAK UPPER LOW OVER THE SOUTHERN KUSKOKWIM VALLEY WILL MOVE
SOUTHWEST AND DISSIPATE BY LATE SUNDAY.  A STRONG RIDGE OF HIGH
PRESSURE WILL FORM OVER SOUTHWEST ALASKA AND THE GULF OF ALASKA BY
MONDAY MORNING. THIS RIDGE WILL ROTATE AND BECOME A LARGE AMPLITUDE
BLOCKING RIDGE EXTENDING FROM THE MACKENZIE DELTA TO THE WEST COAST
OF CALIFORNIA BY LATE TUESDAY. THE RIDGE WILL MOVE SLOWLY EASTWARD
LATER NEXT WEEK.

A FACTOR IN THE LOCAL FORECAST.

.SHORT TERM FORECAST...
MOISTURE WILL BE RETURN TO SOUTH CENTRAL ALASKA TODAY AND TONIGHT AS
A WEAK TROUGH OF LOW PRESSURE MOVES ACROSS PRINCE WILLIAM SOUND TO
COOK INLET SAT NIGHT. THIS COMBINED WITH SOUTHWEST FLOW ALOFT SHOULD
BRING LIGHT SNOW TO SOUTH CENTRAL SAT NIGHT. TEMPERATURES WILL
MODERATE DUE TO AN INCREASE OF CLOUDS AND WARMER AIR ALOFT.

.LONG TERM FORECAST...
DEEP SOUTHERLY FLOW WILL PERSIST NEXT WEEK WITH THE FOCUS OF THE
WARMEST AIR MOVING TO THE PANHANDLE BY FRIDAY.  THE WEST COAST NORTH
AMERICAN RIDGE IS EXPECTED TO BECOME A SIGNIFICANT BLOCKING RIDGE. BY
THE END OF THE WEEK THE RIDGE LOOKS LIKE IT WILL MOVE SLIGHTLY EAST
BUT WILL REMAIN A STRONG BLOCKING FORCE ALLOWING WARM SOUTHERLY FLOW
TO CONTINUE OVER ALASKA.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALE WARNING 130 132 138 140 155 160 165 170 171 172 175
                        176 179 180 185.
         HEAVY FREEZING SPRAY 121 160 180 185.
FIRE WEATHER...NONE

RHH JAN 10