Small Craft Advisory 755, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
300 PM ADT FRI SEP 14 2007

.MODEL DISCUSSION...MODELS ARE ALL IN GOOD AGREEMENT FOR THE FIRST 36
HOURS OF THE OVERNIGHT MODEL RUNS. AFTER THAT THERE ARE SOME
DIFFERENCES WORTH NOTING. THE BIGGEST DIFFERENCE AT THIS TIME IS WITH
THE LOW IN THE GULF OF ALASKA AND HOW IT PROCEEDS SATURDAY NIGHT INTO
SUNDAY, THE MOST REASONABLE SOLUTION COMES FROM THE ECMWF MODEL WHICH
BRINGS THIS LOW TOWARD CAPE SPENCER.
THE OTHER BIG FEATURE TO WATCH IS A VERY STRONG LOW THAT WILL MOVE
INTO THE BERING SEA EARLY NEXT WEEK. THE MODELS ARE VERY CONSISTENT
AND IN GOOD AGREEMENT THAT THIS LOW WILL BE VERY STRONG AND IN THE
BERING SEA. HOWEVER THE GFS NAM AND ECMWF ARE ALL DIFFERENT IN HOW
THE LOW WILL MOVE AND WHAT THE STRENGTH WILL BE. HARD TO SAY AT THIS
POINT WHICH IS THE CLOSEST SOLUTION BUT ECMWF MAY BE THE BEST
SOLUTION AS IT IS SIMILAR TO THE NAM IN STRENGTH AND NOT TOO FAR OFF
FROM THE GFS MODELS MEAN POSITION WHEN LOOKING AT THE GFS ENSEMBLE.

.ANALYSIS AND UPPER LEVELS...THE LOW ENTERING THE GULF IS
STRENGTHENING AS EXPECTED. GALE FORCE WINDS ARE OCCURRING IN THE GULF
OF ALASKA OFFSHORE REGION THOUGH THEY ARE NOT EXPECTED TO REACH THE
COASTAL WATERS IN THE ANCHORAGE FORECAST AREA BUT PUSH INTO SOUTHEAST
ALASKA. THIS LOW WILL MOVE TO JUST WEST OF YAKUTAT SATURDAY MORNING
AND THEN PROCEED SOUTHEASTERLY TOWARD CAPE SPENCER AND WEAKEN.
THE REMNANTS OF THE LOW THAT CAME THOUGH MAINLAND ALASKA A FEW DAYS
AGO PERSIST IN THE CHUKCHI SEA. THIS IS KEEPING SOUTHWEST ALASKA AND
THE BERING SEA IN SOUTHWEST FLOW WITH THE ASSOCIATED SHOWERS AND FOG
ONE WOULD EXPECT IN THIS PATTERN.

.SHORT TERM FORECAST...THE LOW IN THE GULF WILL BRING RAIN THROUGH
SATURDAY FROM PRINCE WILLIAM SOUND EAST. THE WESTERN KENAI PENINSULA
THROUGH THE SUSITNA VALLEY WILL BE ON THE EDGE OF THE PRECIPITATION
BUT MAY MISS IT DUE TO THE ENERGY IN THE STORM MOVING TOO FAR TO THE
EAST. KODIAK SHOULD MOSTLY AVOID PRECIPITATION WITH THIS SYSTEM AND
IN FACT SEE SOME CLEARING AS THE FLOW BECOMES NORTHWEST OVERNIGHT.
SOUTHWEST ALASKA REMAINS IN SOUTHWEST FLOW THAT WILL KEEP SHOWERS IN
THAT AREA. EXPECT MORE COASTAL FOG IN SOUTHWEST ALASKA SATURDAY
MORNING.

.LONG TERM FORECAST...THE BIG STORY IN THE LONG TERM WILL BE THE
LARGE LOW THAT WILL MOVE INTO THE WESTERN ALEUTIANS BEGINNING LATE IN
THE WEEKEND. THIS LOW WILL BE THE STRONGEST LOW OF THE SEASON SO FAR
WITH THE CENTRAL PRESSURE FORECAST TO DROP TO 960 MB OR LESS AS IT
MOVES INTO THE BERING SEA. THIS WILL BRING RAIN AND STRONG WINDS TO
THE ENTIRE BERING SEA AREA BY MONDAY. INLAND AREAS OF SOUTHWEST
ALASKA WILL SEE WINDS AND PRECIPITATION FROM THIS SYSTEM AS IT MOVES
TO THE NORTHEAST AND SLOWLY WEAKENS THROUGH THE MIDDLE OF NEXT WEEK.
THIS LOW WILL HELP AMPLIFY A RIDGE OVER SOUTH CENTRAL ALASKA EARLY
NEXT WEEK.

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

SEP 07