Small Craft Advisory 387, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
400 PM ADT THU APR 26 2007

.MODEL DISCUSSION...MODELS IN GOOD AGREEMENT FROM THE OVERNIGHT RUNS.
IN THE EAST THERE IS VERY LITTLE DIFFERENCE. THE MAIN FEATURE IS THE
LOW IN THE GULF OF ALASKA AND ALL FOUR MAJOR MODELS ARE VERY CLOSE ON
POSITION AND WITHIN A FEW MB THROUGH 60 HOURS. OUT WEST THE MODELS
HAVE THE SAME GENERAL IDEA ON THE LOW MOVING INTO THE AREA THIS
WEEKEND BUT THERE ARE SOME DIFFERENCES IN THE DETAILS. GFS SOLUTION
LOOKS THE MOST REASONABLE IN THIS AREA HOWEVER.

.ANALYSIS AND UPPER LEVELS...MAINLAND ALASKA REMAINS UNDER A BROAD
LONG WAVE TROUGH THAT IS KEEPING UPPER LEVEL FLOW WEAK OVER MOST OF
THE AREA. THE JET STREAM HAS DECOUPLED FROM THE LOW IN THE GULF OF
ALASKA LEAVING IT TO SPIN IN PLACE AND SLOWLY WEAKEN. THE JET STREAM
WILL ALSO REMAIN SOUTH OF THE ALEUTIAN ISLANDS JUST SOUTH OF THE LOW
MOVING INTO THE AREA THIS WEEKEND. BASIC UPPER LEVEL STORY WILL
THEREFORE BE WEAK FLOW ALOFT INTO EARLY NEXT WEEK FOR MAINLAND
ALASKA.

.SHORT TERM FORECAST...THE LOW IN THE GULF WILL BRING SOME CLOUDS
INTO SOUTH CENTRAL ALASKA OVERNIGHT AND RAIN SHOWERS ALONG THE COAST
AS WELL. KODIAK ISLAND MAY SEE SOME CLEARING THIS EVENING BEFORE THE
CLOUDS AROUND THE LOW MOVE BACK INTO THE AREA. BERING SEA AND
ALEUTIAN ISLANDS AS WELL AS AK PENINSULA WILL REMAIN IN NORTH TO
NORTHWEST FLOW AND THE WILL KEEP SOME MARINE STRATUS AND SHOWERS IN
THESE AREAS. PRIBILOF ISLANDS ARE THE ONLY AREA SEEING SNOW AS THE
PRECIPITATION TYPE. THERE IS A GOOD CHANCE THAT PRECIPITATION TYPE
WILL REMAIN SNOW THERE AS THE NEXT LOW MOVES INTO THE CENTRAL
ALEUTIANS AS THE SYSTEM DOES NOT BRING MUCH WARM AIR THAT FAR NORTH
ON THE CORE OF COLD AIR REMAINS OVER THE CENTRAL TO EASTERN BERING
SEA.

.LONG TERM FORECAST...THE LONG WAVE TROUGH REMAINS OVER US THROUGH
THE WEEKEND AND WILL KEEP THE JET STREAM SOUTH OF MAINLAND ALASKA AND
UPPER LEVEL FLOW RELATIVELY WEAK. SCATTERED SHOWERS WILL POP UP IN
INTERIOR REGIONS WITH SOME RAIN ALONG COASTAL AREAS.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 120 130 132 176.
FIRE WEATHER...NONE.

APR 07