Gale Warning 958, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
1222 PM AKST THU DEC 10 2009

.MODEL DISCUSSION...GFS AND NAM IN GOOD AGREEMENT THROUGH 72 HOUR AND
THEN SIGNIFICANT DIFFERENCES ON NORTH PACIFIC LOW MOVEMENT ALONG
160W...WOULD GO WITH GFS SOLUTION AS THIS IS THE SOUTHERN BOUNDARY ON
NAM GRID.

.ANALYSIS AND UPPER LEVELS...UPPER LEVEL NW TO SE TROUGH REMAINS IN
SITU WITH WARM AIR IN THE MIDDLE AND UPPER TROPOSPHERE.  VERY LARGE
INVERSIONS PERSIST AND WILL REMAIN OVER SOUTHCENTRAL AND THE INTERIOR
UNTIL SATURDAY WHEN SOME COOLER AIR FROM THE ARCTIC MOVES SOUTHWARD.
WITH LIGHT OR CALM WINDS FOG AND STRATUS ARE COMMON PLACE...MAINLY
NEAR THE COAST.

.SHORT TERM FORECAST...ACTIVE WEATHER IS CONFINED TO THE ALEUTIANS
WHERE A COMPLEX LOW SOUTH OF THE CHAIN DEEPENS FRIDAY AND MOVES OVER
ATTU LATE FRIDAY NIGHT AND CONTINUES WESTWARD SATURDAY. A NORTH
PACIFIC LOW WELL SOUTH OF THE CHAIN MOVES TO 50N SATURDAY AFTERNOON
AND THEN REMAINS QUASI-STATIONARY THEREAFTER. MODERATE SOUTH WINDS
OVER THE WESTERN ALEUTIANS IS EXPECTED FRIDAY THROUGH SUNDAY.

LITTLE CHANGE TO CURRENT WEATHER OVER SOUTHWESTERN AND SOUTHCENTRAL
ZONES OVER THE NEXT SEVERAL DAYS. PERIODS OF STRATUS AND FOG
INTERMIXED WITH CLEAR SKIES.

.LONG TERM FORECAST...UPPER LEVEL RIDGE DISSIPATES OVER THE WEEKEND
ALLOWING A NORTH PACIFIC STORM TO MOVE INTO THE SOUTHERN GULF OF
ALASKA ON TUESDAY. THE MODELS INDICATING THAT A UPPER LEVEL LOW OVER
THE BEAUFORT SEA ON SUNDAY WILL MOVE INTO THE STATE ON LATE MONDAY
GENERATING COOLER AIR TEMPERATURES OVER THE REGION. WEAK HIGH
PRESSURE FORMING OVER THE NORTHWESTERN BERING SEA EARLY NEXT WEEK.

GFS HINTING AT AN INVERTED SURFACE TROUGH IN COMBINATION WITH UPPER
LEVEL LOW COULD PRODUCE SOME SNOW OVER SOUTHCENTRAL AND AND EASTERN
HALF OF SOUTHWEST ZONES ON MONDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...175?
FIRE WEATHER...NONE

JMP DEC 09