Small Craft Advisory 717, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
300 PM ADT MON SEP 3 2007

.MODEL DISCUSSION...MODELS ALL START OFF REASONABLY GOOD. THE LOW
NEAR BRISTOL BAY IS HANDLED VERY SIMILAR BY ALL MODELS. THE BIG
DIVERGENCE BETWEEN MODELS COMES BEGINNING AROUND WEDNESDAY AS A LOW
MOVES INTO THE WESTERN BERING SEA AND ANOTHER LOW WELL SOUTH OF THE
ALASKA PENINSULA MOVES TOWARD THE GULF OF ALASKA. THE MODELS ALL HAVE

THE LOW IN THE WESTERN GULF BUT AS USUAL THEY ARE VARIED IN JUST HOW
IT WILL BEHAVE. THE SAME GOES FOR THE LOW MOVING TOWARD THE GULF OF
ALASKA ON WEDNESDAY AND THURSDAY. THE MODELS RECOGNIZE A WAVE IS
PROPAGATING TOWARD THE AREA BUT THERE IS LARGE DIFFERENCE BETWEEN THE
MODELS IN BOTH POSITION AND STRENGTH. THINKING HAS BEEN TO LEAN
HEAVILY TOWARD THE GFS SOLUTION AND I SEE NO REASON TO DEVIATE FROM
THAT AT THIS TIME. THE GFS HAS BEEN RATHER CONSISTENT WITH THE
POSITION AND STRENGTH OF THIS FEATURE FOR A NUMBER OF MODEL RUNS.

.ANALYSIS AND UPPER LEVELS...UPPER LEVEL JET IS VISIBLE ON THE IR
SATELLITE MOVING FROM THE NORTH PACIFIC INTO THE GULF OF ALASKA. THE
MAIN LOW THAT IS AFFECTING THE WEATHER OVER THE ENTIRE AREA IS
SITUATED NEAR BRISTOL BAY AND WILL MOVE INTO THE NORTHWESTERN GULF OF
ALASKA TUESDAY. OVERALL AN UPPER LEVEL TROUGH SITS OVER THE AREA AND
THE TEMPERATURES ALOFT ARE NOTICEABLY COOLER THAN A WEEK OR SO AGO.

.SHORT TERM FORECAST...RAIN AND WIND WILL CONTINUE THROUGH THE NIGHT
ALONG THE GULF COAST AND ALEUTIAN RANGE. NORTHWEST FLOW OVER THE
BERING SEA AREA WILL BRING SHOWERS TO THE ALEUTIAN ISLANDS AND
EASTERN BERING SEA. WINDS WILL INCREASE ALONG TURNAGAIN ARM UNTIL THE
LOW MOVES INTO THE GULF OF ALASKA. SUBSIDENCE AHEAD OF THE FRONT IS
CAPPING THE ATMOSPHERE IN SOUTH CENTRAL ALASKA TODAY AND KEEPING WHAT
WAS AN UNSTABLE ATMOSPHERE ON THE RADIOSONDE FROM DEVELOPING ANYTHING
MORE THAN AN ISOLATED SHOWER THIS AFTERNOON AND EVENING.

.LONG TERM FORECAST...THERE IS STILL SOME UNCERTAINTY TO THE LONG
TERM FORECAST. HOWEVER IT IS LIKELY THAT THE WESTERN AND CENTRAL
ALEUTIANS WILL GET A BIT OF RAIN MID WEEK AS THE LOW MOVES INTO THAT
AREA. SOUTH CENTRAL AND SOUTHWEST ALASKA ARE A LITTLE TRICKIER SINCE
THERE MAY NOT BE A LOT OF CLEARING BEHIND THE CURRENT SYSTEM DUE TO
THE UPPER LEVEL FLOW REMAINING FROM A SOUTHERLY AND DIRECTION
ALLOWING PLENTY OF MOISTURE TO KEEP MOVING INTO THE AREA.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 120 125 130 132 138 150 155 165 170.
FIRE WEATHER...NONE.

SEP 07