Winter Storm Watch 4, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AKST TUE NOV 10 2009

.ANALYSIS AND UPPER LEVELS...
NEGATIVELY TILTED UPPER TROUGH OVER ALASKA THIS MORNING WITH A DEEP
UPPER LOW OVER NORTHEAST SIBERIA AND A STRONG RIDGE ALONG ABOUT 170
WEST LONGITUDE. STRONG JET STREAM EXITING ASIA JUST NORTH OF
HOKKAIDO AND RACING ACROSS THE NORTHERN BERING SEA BEFORE DIPPING
SOUTHEAST AND ENTERING THE GULF OF ALASKA NEAR KODIAK.

.SHORT TERM FORECAST...
UPPER TROUGH AXIS IS JUST EAST OF ANCHORAGE THIS MORNING AND SHOULD
EXIT SOUTH CENTRAL ALASKA LATER TODAY. THE NEXT SYSTEM IS STILL
CONSOLIDATING OVER THE BERING SEA AND IS BEGINNING TO AFFECT
SOUTHWEST ALASKA ALREADY. THIS SYSTEM WILL SPIN UP INTO A MAJOR
STORM TUESDAY NIGHT AND WILL MOVE INTO SOUTH CENTRAL ALASKA
WEDNESDAY MORNING. AS THIS SYSTEM EXITS SOUTH CENTRAL ALASKA ON
THURSDAY ITS PARENT LOW OVER NORTHERN ALASKA WILL STALL AND BECOME
THE STEERING LOW.

.LONG TERM FORECAST...
THE MEAN UPPER LOW POSITION OVER ALASKA WILL STRENGTHEN AND SOLIDIFY
KEEPING BELOW NORMAL HEIGHTS OVER THE STATE THROUGH THE EXTENDED.
THERE IS THE POSSIBILITY OF A STRONG LOW (BELOW 950 MB) DEVELOPING
IN THE GULF EARLY IN THE WEEKEND...BUT THIS IDEA IS NOT YET FULLY
AGREED UPON BY THE NUMERICAL GUIDANCE.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...WINTER STORM WATCH 145.
MARINE...STORM WARNING 130.
         GALE WARNING 120 121 125 129 132 140 141 155 170
                     172 175 179 180 185.
FIRE WEATHER...NONE.

LUDWIG NOV 09