Small Craft Advisory 291, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKDT MON APR 1 2013

.MODEL DISCUSSION...
THE NUMERICAL MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH 84 HOURS.
THIS IS PARTLY DUE TO THE HIGH AMPLITUDE UPPER LEVEL PATTERN...WHICH
IS A FAIRLY PREDICTABLE REGIME. THEREFORE THE FORECAST CONFIDENCE
IS HIGHER THAN NORMAL. THE DIFFERENCES THAT DO EXIST ARE MINOR. THEY
CONCERN A WEAK FRONT WORKING INTO THE NORTHERN GULF OF ALASKA ON
TUESDAY AND TUESDAY NIGHT...AND THE DEVELOPMENT OF A TRIPLE POINT
LOW TOWARDS THE END OF THE SHORT TERM.

.ANALYSIS AND UPPER LEVELS...
THERE IS CYCLONIC FLOW OVER SOUTHERN ALASKA ASSOCIATED WITH AN UPPER
LEVEL LOW OVER THE EASTERN GULF OF ALASKA AND MOVING EAST. THERE IS
ANOTHER RAPIDLY DEVELOPING LOW SOUTH OF THE WESTERN ALEUTIANS. A
DISSIPATING FRONT IS DRAPED ACROSS THE EASTERN BERING SEA. AN UPPER
LEVEL LOW CENTERED JUST NORTH OF THE BERING STRAIT EXTENDS ACROSS
SOUTHWEST ALASKA.

.SHORT TERM FORECAST...
FOR SOUTH CENTRAL AND SOUTHWEST ALASKA...THE EASTERN GULF LOW WILL
WEAKEN AND MOVE INLAND INTO THE PANHANDLE TONIGHT. THIS WILL LEAVE A
WEAK RIDGE OVER THE AREA TUESDAY THROUGH THURSDAY. THERE IS A CHANCE
OF SHOWERS OVER THE MOUNTAINS THIS EVENING...THEN AGAIN OVER THE
WRANGLE MOUNTAINS ON TUESDAY DUE TO THE CYCLONIC FLOW AND COLD AIR
ALOFT. OTHERWISE CHANCES OF PRECIPITATION WILL BE LIMITED TO COASTAL
AREAS TUESDAY NIGHT AND WEDNESDAY ASSOCIATED WITH A VERY WEAK UPPER
LOW OVER THE GULF...AND THEN ONLY OVER KODIAK WEDNESDAY NIGHT AND
THURSDAY.

FOR THE ALEUTIAN ISLANDS AND BERING SEA...
THE FRONT OVER THE EASTERN BERING SEA AND ALASKA PENINSULA WILL
CONTINUE TO WEAKEN TONIGHT AND DISSIPATE TUESDAY. THE LOW SPINNING
UP SOUTH OF THE WESTERN ALEUTIANS WILL MATURE THIS EVENING AND WORK
EASTWARDS. BY WEDNESDAY AFTERNOON IT WILL STALL SOUTH OF THE CENTRAL
ALEUTIANS...WITH A TRIPLE POINT LOW FORMING SOUTH OF THE ALASKA
PENINSULA ON THURSDAY. THE OCCLUDED FRONT FROM THIS LOW WILL WORK
NORTH AND EAST THROUGH WEDNESDAY AFTERNOON...MOVING INTO THE CENTRAL
ALEUTIANS THIS EVENING...THE EASTERN ALEUTIANS TUESDAY AND THE
ALASKA PENINSULA AND PRIBILOF ISLANDS TUESDAY NIGHT...THEN STALL AND
WEAKEN AS THE TRIPLE POINT LOW FORMS.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORM WARNING 175.
         GALE WARNING 155 165 170 171 172 176 179.
FIRE WEATHER...NONE.

LUDWIG APR 13