Small Craft Advisory 991, NWS Anchorage, AK

AREA FORECAST DISCUSSION...UPDATED
SOUTHCENTRAL AND SOUTHWEST ALASKA
315 PM AST SAT NOV 24 2007

UPDATED TO ADD WARNINGS.

.MODEL DISCUSSION...NAM AND GFS FOR THE 12Z RUN INITIALIZE AND REMAIN
IN GOOD AGREEMENT FOR THE FIRST 36 HOURS.  AFTER 36 HOURS THE NAM
LIKES TO TAKE THE CENTER OF THE ELONGATED GULF OF ALASKA LOW OVER
YAKUTAT BY MONDAY AFTERNOON.  IN CONTRAST THE GFS KEEPS THE EAST-WEST
ORIENTATION FROM KODIAK OVER TOWARD THE EASTERN GULF.

ALL MODELS SHOW A DEVELOPING LOW SUNDAY SOUTH OF THE CENTRAL
ALEUTIANS WITH A MIN PRESSURE IN THE 955 MB TO 960 MB RANGE BY SUNDAY
NIGHT.  NAM MOVES THIS SYSTEM THROUGH THE CENTRAL ALEUTIANS ON MONDAY
WHILE THE GFS RETAINS THE LOW CENTER JUST SOUTH OF THE ALEUTIAN
CHAIN.

GFS IS THE MODEL OF CHOICE TODAY.

.ANALYSIS AND UPPER LEVELS...AS OF THIS MORNING A LOW OVER COLD BAY
WITH GOOD UPPER LEVEL SUPPORT WILL SLOWLY WEAKEN AS IT MOVES INTO
BRISTOL BAY TONIGHT AND THEN CONTINUES TO WEAKEN ON SUNDAY. MAIN
POLAR JET AXIS IS BETWEEN 35N AND 45N OVER THE CENTRAL PAC BUT
EASTERN EXTENSION MOVES INTO GULF OF ALASKA SUNDAY MORNING.

.SHORT TERM FORECAST...ISOLATED SNOW SHOWERS OVER A LARGE PART OF THE
WEST AND SOUTHCENTRAL THIS AFTERNOON AND EVENING.  WEAKENED OCCLUDED
FRONT MOVES THROUGH BRISTOL BAY ZONES THIS AFTERNOON AND THEN INTO
COOK INLET THIS EVENING.  SOUTHEASTERLY FLOW UP THROUGH THE MID
TROPOSPHERE SHOULD PRODUCE SOME RESPECTABLE AMOUNTS OF PRECIP ALONG
THE COAST TONIGHT.  SNOWLINE RANGING FROM 2000 FT ALONG THE COAST TO
NEAR SEA LEVEL IN NORTHERN COOK INLET.  MIXED PHASED PRECIP IN
BRISTOL BAY AT SEA LEVEL. STRONG EAST WINDS ALONG THE NORTH GULF
COAST AND THROUGH GAPS SATURDAY NIGHT THROUGH SUNDAY AFTERNOON.

.LONG TERM FORECAST...DESPITE MODEL DISCREPANCIES...EXPECTING VERY
STRONG EAST WINDS IN THE NORTHERN HALF OF THE GULF OF ALASKA LATE
SUNDAY MORNING THROUGH EARLY MONDAY MORNING.  GFS INDICATING A FRONT
MOVING THROUGH THE WESTERN AND THEN CENTRAL ALEUTIANS LATE TUE AND
WED.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALES 121 125 140 141 155 160 165 170 171 172 175 180 414
         STORMS 120 130 132 138 150 351 352.
         HEAVY FREEZING SPRAY 180
FIRE WEATHER...NONE.

LEWF NOV 07