Small Craft Advisory 311, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
200 PM ADT SAT APR 9 2005

.DISCUSSION...

UPPER LEVELS...UPPER LOW OVER THE GULF OF ALASKA WILL CONTINUE TO
SLOWLY DRIFT EAST WITH TIME WITH YET ANOTHER UPPER LOW SWINGING IN
FROM THE WEST. LITTLE CHANGE IN THE UPPER LEVELS FOR THE NEXT 120
HOURS OVERALL.

SURFACE...A 998 MB LOW IN THE SOUTHERN GULF OF ALASKA WILL REMAIN
STATIONARY AND SLOWLY WEAKEN THROUGH SUNDAY NIGHT. THIS IS BRINGING
SHOWERY CONDITIONS TO THE NORTH GULF COAST AND GENERAL MID TO HIGH
CLOUDINESS TO THE INTERIOR REGIONS OF SOUTH CENTRAL ALASKA. IN THE
WEST SNOW SHOWERS CONTINUE IN THE NORTHWEST FLOW ALL ACROSS THE
BERING AND ALEUTIAN REGIONS WITH LITTLE CHANGE EXPECTED IN THE NEXT
36 HOURS.

MODELS...ON THE SURFACE AT 00Z THIS AFTERNOON THE BIG THREE MODELS
ARE FAIRLY CLOSE IN SOLUTIONS. THIS CONTINUES THROUGH 60 HOURS WHEN
THE FIRST SIGN OF MAJOR DIFFERENCES OCCUR. THE UKMET AND NAM DEVELOP
A TRIPLE POINT LOW SOUTH OF ADAK WHERE THE GFS IS SLOWER OVER IN THE
WEST...OVER IN THE GULF A BROAD AREA OF LOW PRESSURE IS NOTED BY ALL
THE MODELS. IN THE EASTERN DOMAIN EITHER THE NAM OR GFS HANDLE THE
SURFACE IN SIMILAR FASHION THROUGH 84 HOURS. IN THE WEST LIKE THE NAM
BY KEEPING THE SURFACE LOWS TO THE SOUTH OF CHAIN WHICH HAS BEEN THE
TREND FOR THE PAST WEEK. FOR GENERAL GUIDANCE WE HAVE DECIDED ON NAM
FOR THIS AFTERNOONS FORECAST PACKAGE. THIS IS BASED ON THE RUN TO RUN
HANDLING OF THE SYSTEMS SOUTH OF THE CHAIN. THE GFS HAD AN OFF RUN
LAST NIGHT WITH THE NAM HOLDING COURSE WITH THE SOUTHERN TRACK
SOLUTION.

FORECAST HIGHLIGHTS...IN THE EAST...THE MOST PROBLEMS WILL BE FIRST
PERIOD WITH WINDS. OTHERWISE THE COASTAL AND OFFSHORE AREAS WILL
REMAIN UNDER WEAKENING LOW PRESSURE FOR GENERALLY LIGHT WINDS AND
SHOWERY CONDITIONS THROUGH THE PERIOD. VERY LITTLE ACTIVITY IS
EXPECTED FOR THE SOUTH CENTRAL INTERIOR. TEMPERATURES OVER SOUTH
CENTRAL THROUGH THE PERIOD LOOK TO BE RIGHT ALONG WITH CLIMO NORMALS.
NO MAJOR STORMS OR PROBLEMS EXPECTED THIS FORECAST PACKAGE.  ...IN
THE WEST...NORTHWEST FLOW SNOW SHOWERS WILL FINALLY BEGIN TO WIND
DOWN SUNDAY AND A SHORT LIVED SURFACE RIDGE WILL GIVE THE EASTERN
BERING AND ALEUTIANS A BREAK FROM THE NORTH WIND AND SNOW SHOWERS ON
MONDAY. THEN THE NEXT LARGE NORTH PACIFIC SYSTEM BRINGS A FRONT AND
ANOTHER LOW INTO THE CENTRAL AND WESTERN AREAS ON TUES AND TRACKS IT
TO THE EAST WITH THE EXTENDED FORECAST.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALE...120 170 171 176
         HEAVY FREEZING SPRAY...179
FIRE WEATHER...NONE

PROTON APR 05