Small Craft Advisory 1035, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
300 PM AST SUN DEC 9 2007

.MODEL DISCUSSION...MODELS ARE DOING FINE OUT WEST IN THE SHORT TERM.
THE BIGGEST ISSUE IN THE BERING SEA AREA IS WHEN THE LOW MOVES INTO
THE EASTERN ALEUTIAN ISLANDS ON TUESDAY THE GFS AND THE ECMWF MODELS
ARE A BIG DISAGREEMENT AS TO THE PATH OF THE LOW. THE ECMWF WANTS TO
SHOOT IT SOUTH OF THE ALEUTIANS INTO THE GULF OF ALASKA BY WEDNESDAY
WHILE THE GFS IS BRINGING IT JUST NORTH OF THE ALEUTIANS BEFORE
CROSSING KODIAK ISLAND WEDNESDAY NIGHT AND INTO THE GULF EARLY ON
THURSDAY. AS OF NOW THE GFS SEEMS TO HAVE THE PREFERABLE SOLUTION DUE
TO THE JET STREAM POSITIONING AT THAT TIME. IN ORDER FOR THE ECMWF
SOLUTION TO WORK THE LOW MUST GET CAUGHT IN THE JET STREAM AND MOVE
IN IT. THE JET LOOKS TO BE STRONG JUST TO THE SOUTH OF THIS LOW AND
THE UPPER LEVEL FLOW NORTH OF IT IS NOT STRONG AND THEREFORE THE LOW
WILL PROBABLY TAKE THE SLOWER AND MORE NORTHERLY TRACK.

IN THE EAST THE MODELS ARE IN GOOD AGREEMENT THROUGH 36 HOURS AND
THEN BEGIN TO DIVERGE WHEN THE LOW COMES TO THE SOUTHERN TIP OF THE
KENAI PENINSULA. AT THIS TIME THE GFS ECMWF AND UKMET TURN THE LOW
OVER THE NORTH GULF COAST WHILE THE NAM BRINGS IT UP THE INLET. THE
OTHER MODELS HAD A SIMILAR SOLUTION TO THE NAM THE LAST FEW DAYS BUT
HAVE ALL CHANGED TO THE NORTH GULF COAST SOLUTION AND THAT LOOKS MORE
REASONABLE. THE OPERATIONAL RUN OF THE GFS BRINGS THE LOW SOUTHEAST
OF MIDDLETON ISLAND BUT THE GFS MEAN ENSEMBLE SOLUTION HAS IT FARTHER
NORTH. THIS SYSTEM WILL PROBABLY BE IN THE NORTH GULF BEFORE IT TIPS
ITS HAND AS TO WHETHER IT WILL GO INTO SOUTHERN PRINCE WILLIAM SOUND
ON ONSHORE CLOSER TO YAKUTAT. THERE WILL BE CONSIDERABLE COLD
ADVECTION THROUGH THE BARREN ISLAND AREA BEHIND THIS LOW AND THAT
COLD AIR ENTRAINING INTO IT WILL ALSO LIKELY HAVE AN IMPACT ON IT. A
GOOD SUPPOSITION IS THAT IT WILL KEEP THE LOW A LITTLE STRONGER AND
MOVING A LITTLE MORE TO TOWARD PRINCE WILLIAM SOUND. THERE WILL ALSO
BE COLD ADVECTION OVER THE ANCHORAGE BOWL MONDAY NIGHT AND TUESDAY
WHICH WOULD AID IN THE DEVELOPMENT OF SNOW OVER ANCHORAGE SHOULD THIS
SYSTEM HEAD TOWARD THE SOUND. THIS BEARS WATCHING THE NEXT FEW DAYS.

.ANALYSIS AND UPPER LEVELS...THE LOW SOUTHWEST OF ST MATTHEW ISLAND
WILL DISSIPATE OVERNIGHT WHILE THE MAIN LOW IN THE BERING SEA IS NOW
THE 985 MB LOW NORTHEAST OF ST PAUL.  THE LOW THAT WILL MOVE INTO THE
GULF OF ALASKA IS EASILY SEEN SOUTH OF KODIAK ISLAND AROUND 50N.

.SHORT TERM FORECAST...THE EASTERN BERING SEA LOW IS BRINGING A LOT
OF WARM AIR INTO SOUTHWEST ALASKA AND THEREFORE RAIN INTO WESTERN
BRISTOL BAY. EASTERN BRISTOL BAY IS LARGELY DOWNSLOPING OUT AND DRY.
THE COLD AIR IN PLACE OVER THE KUSKOKWIM DELTA REGION IS ALLOWING THE
OVERRUNNING MOISTURE TO PRECIPITATE OUT AS SNOW...BUT THAT WILL TURN
TO RAIN OR A RAIN-SNOW MIX AS THE WARM AIR MOVES FARTHER INTO THAT
AREA. KODIAK WILL SEE RAIN AS THE APPROACHING GULF LOW MOVES UP TO
THAT AREA.

.LONG TERM FORECAST...MUCH OF THE LONG TERM FORECAST FOR BOTH AREAS
HINGES ON THE TRACK OF THE LOW MOVING INTO THE EASTERN ALEUTIANS ON
TUESDAY THAT WAS DISCUSSED IN THE MODEL DISCUSSION SECTION.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 125 132 138 140 141 150 155 160 165 170 172 179.
         STORM 120 130.
FIRE WEATHER...NONE.

DEC 07