Gale Warning 777, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
300 PM ADT SUN OCT 28 2007

.ANALYSIS AND UPPER LEVELS...AN UPPER LEVEL LOW IN THE BERING SEA AND
THE ASSOCIATED SURFACE LOW WILL MOVE ACROSS THE ALASKA PENINSULA
TONIGHT. THIS LOW STILL HAS A LOT OF UPWARD VERTICAL MOTION AS CAN BE
SEEN ON THE IR SATELLITE. A SECONDARY LOW CAN BE SEEN ON THE VISIBLE
SATELLITE A LITTLE FARTHER WEST IN THE BERING SEA BUT THIS LOW DOES
NOT HAVE MUCH UPPER LEVEL SUPPORT AND WILL NOT HAVE MUCH IMPACT.
THE BIG SYSTEM THAT IS THE REMNANTS OF TROPICAL STORM FAXAI IS EASILY
SEEN ON THE IR SATELLITE SOUTH SOUTHWEST OF THE ALEUTIAN ISLANDS. THE
JET STREAM FEEDING INTO THIS SYSTEM STILL HAS A TROPICAL CONNECTION
ALL THE WAY INTO THE SOUTH CHINA SEA. IT IS NOT AS PRONOUNCED AS
YESTERDAY BUT IT IS STILL BRINGING A LOT OF WARM AIR INTO THE SYSTEM.

THOUGH THERE IS NOT A GIANT AMOUNT OF COLD AIR AVAILABLE IN THE
BERING SEA FOR THIS SYSTEM TO TAP INTO...THERE IS ENOUGH THAT THIS
LOW WILL REALLY DEEPEN QUICKLY AS IT MERGES WITH THE LOW IN THE
BERING SEA MONDAY AFTERNOON SOUTHWEST OF KODIAK ISLAND.

.MODEL DISCUSSION...AS HAS BEEN MENTIONED NUMEROUS TIMES THE MODELS
ARE STILL HAVING SOME DIFFICULTY HANDLING THE EXTRA TROPICAL SYSTEM.
FORTUNATELY AS IT GETS CLOSER THE DIFFERENCES BETWEEN MODELS AND THE
RUN TO RUN CONSISTENCY OF EACH MODEL IS IMPROVING. THE LATEST RUNS
ARE DIVIDED INTO TWO CAMPS...THE FIRST IS THE GFS AND UKMET SOLUTION
WHICH DOWNPLAYS THE EXTRA TROPICAL SYSTEM AND DEEPENS THE BERING SEA
LOW AND MOVES IT ONSHORE IN NORTHEAST BRISTOL BAY. THERE ARE TWO
REASONS NOT TO LIKE THIS SOLUTION. THE FIRST IS THAT THERE IS A
SIGNIFICANT AMOUNT OF UPPER LEVEL SUPPORT TO KEEP THE LOW FURTHER
SOUTH AND THE COLD ADVECTION FROM THE AIR IN THE WESTERN BERING SEA
WILL ALSO STRENGTHEN THE LOW SOUTH OF THE ALASKA PENINSULA. THEREFORE
IT POINTS TO THE SOLUTION THAT IS CLOSER TO WHAT BOTH THE ECMWF AND
NAM HAVE. THE NAM AND ECMWF BOTH MAKE TO EXTRA TROPICAL SYSTEM THE
DOMINANT LOW AND HAVE IT ABSORB THE LOW THAT IS CURRENTLY IN THE
BERING SEA SOUTHWEST OF KODIAK ISLAND TOMORROW. THE NAM AND ECMWF
HAVE SOME SIGNIFICANT DIFFERENCES THOUGH. IN THE END THE NAM SOLUTION
WHICH BRINGS THE LOW INTO COOK INLET IN TUESDAY IS THE PREFERRED
SOLUTION. THE ECMWF WANTS TO BRING THE LOW TO MIDDLETON ISLAND
TUESDAY. THIS IS POSSIBLE BUT THE OVERALL CLUES POINT TO THE LOW
MOVING INTO SOUTH CENTRAL ALASKA A LITTLE FARTHER WEST THAN THAT.
EVEN THOUGH THE SOLUTION WILL NOT BE PERFECT THE NAM SHOULD NOT BE
TOO FAR OFF EITHER.

.SHORT TERM FORECAST...AN UPPER LEVEL WAVE IN THE NORTHERN GULF OF
ALASKA WILL CONTINUE TO BRING SHOWERS TO THE COAST AND COASTAL
MOUNTAINS OVERNIGHT. THE LOW IN THE BERING SEA WILL ALSO BRING RAIN
TO THE ALASKA PENINSULA AS IT MOVES THROUGH THAT AREA. FOG IS LIKELY
TO DEVELOP AGAIN IN THE COPPER RIVER BASIN AND THE KUSKOKWIM VALLEY.

.LONG TERM FORECAST...THE BIG LOW WILL MOVE INLAND INTO THE INTERIOR
OF THE STATE BY THE MIDDLE OF THE WEEK BRINGING SOME SNOW SHOWERS TO
SOUTHWESTERN ALASKA AND MOSTLY RAIN EAST OF THE ALASKA RANGE.
ANOTHER LOW IS EXPECTED TO MOVE INTO THE ALEUTIANS AND THEN INTO
SOUTHWEST ALASKA LATE IN THE WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE AND STORM WARNINGS CENTRAL ALEUTIANS THROUGH NORTH GULF
COAST WATERS.
FIRE WEATHER...NONE.

OCT 07