Small Craft Advisory 199, NWS Anchorage, AK

AREA FORECAST DISCUSSION SOUTHWEST ALASKA
200 PM AST FRI MAR 4 2005

.DISCUSSION...

UPPER LEVELS...RIDGING CONTINUES OVER THE CANADIAN ROCKIES IN THE MID
TO UPPER LEVELS. ALEUTIAN LOW HAS DRIFTED TO THE EAST OF THE CHAIN
WITH A STRONG PACIFIC JET. THIS PATTERN AMPLIFIES THROUGH SUNDAY WITH
THE RIDGE OVER THE CANADIAN ROCKIES BUILDING ACROSS THE GREAT LAND
WITH THE ALEUTIAN LOW RETROGRESSING BACK TO NEAR ADAK. AT THIS TIME
THE PACIFIC JET BECOMES MORE NORTH/SOUTH ACROSS THE NORTHEAST PACIFIC
AND GULF OF ALASKA ALLOWING FOR STRONGER SYSTEMS TO MOVE UP ON KODIAK
ISLAND. THIS PATTERN CONTINUES THROUGH 120 HOURS OF THE GFS AND SEEMS
REASONABLE.

SURFACE...A 958 MB LOW SOUTH OF THE ALASKA PENINSULA WITH A FRONT
MOVING UP ON THE SOUTHERN GULF OF ALASKA THIS MORNING WILL BE THE
PRIMARY PLAYER FOR THE EARLY PART OF THE FORECAST. THIS LOW CONTINUES
TO WEAKEN AS IT DRIFTS TO THE WEST AND THE NEXT MAJOR SYSTEM ROUNDS
THE BOTTOM OF THE UPPER TROUGH AROUND 12Z TONIGHT. THE VERY WEAK
FRONT CROSS THE PENINSULA. THE COLD AIR CHANNELED INTO THE DEVELOPING
SYSTEM TO THE SOUTH AND IS CUT OFF FROM THE NORTHERN LOW KEEPING
WINDS BELOW THE STORM LEVEL ACROSS THE WESTERN DOMAIN. THIS NORTHERN
LOW CONTINUES TO WEAKEN AND DRIFT WEST THROUGH SATURDAY NIGHT. THE
SOUTHERN LOW AND ASSOCIATED FRONT BEGINS TO MAKE ITS TURN TOWARDS THE
NORTH AT THIS TIME. THE BUILDING RIDGE OVER THE WESTERN COAST OF
CANADA WILL ALLOW THIS SECOND SYSTEM TO BUILD UP MORE OF A GRADIENT
ACROSS THE EASTERN DOMAIN AND SHOULD PRODUCE MORE WIND THAN THE
PREVIOUS SYSTEM DID. WILL HAVE TO WATCH THE POSITION OF THE FRONT FOR
A POSSIBLE LOW LEVEL BARRIER JET SITUATION SUNDAY FOR THE NORTH GULF
COAST AND MODERATE SNOWS ALONG THE WESTERN SECTIONS OF THE ALASKA
RANGE SUNDAY INTO MONDAY. FURTHER WEST IT/S A GRAVEYARD FOR SURFACE
LOWS WITH WEAK WINDS AND SHOWERS. MAIN ACTIVITY IN THE WESTERN DOMAIN
WILL BE ALONG THE ALASKA PENINSULA AND THE ALASKA RANGE.

MODELS...THE FIRST SYSTEM IS HANDLED IN SIMILAR FASHION BY THE BIG
THREE MODELS THROUGH 24 HOURS. AT THE 30 HOUR PANEL THE UKMET AND GFS
MOVE TO A DOUBLE CENTER WITH THE NAM KEEPING A SINGLE CENTER
PLACEMENT IS PRETTY CLOSE BETWEEN THE MODELS. THE SECOND SYSTEM AGAIN
LIKE THE SLOWER NAM MODEL OVER THE GFS...THE UKMET IS PRETTY CLOSE TO
THE NAM WITH THIS SYSTEM. WITH THE SECOND SYSTEM THE GFS KEEPS THE
LOW TOO STRONG AND MOVES IT TOO FAST INTO THE ALEUTIAN
GRAVEYARD...PREFER THE UKMET/NAM SLOWER AND SIMILAR HANDLING OF THE
WEAKENING PHASE OF THIS LOW. OVERALL FOR BOTH DOMAINS PREFER THE
NAM/UKMET IDEA OVER THE GFS.

FORECAST PROBLEM AREAS...VERY FEW TROUBLES WITH THE FIRST SYSTEM AS
IT CROSSES OVER AND WEAKENS IN THE NEXT 24 HOURS. THE NEXT SYSTEM
POSES A COUPLE OF PROBLEMS. FIRST WINDS ACROSS THE GULF OF ALASKA
WITH THE FRONT APPROACHING. BOUNDARY LAYER WINDS SHOW GOOD STORM
FORCE WINDS IN THE OPEN WATERS AND WILL HAVE TO KEEP AN EYE ON THE
GAP WIND AREAS FOR POSSIBLE WATCH/WARNING SITUATIONS IN THESE AREAS
OF KODIAK ISLAND AND SOUTH CENTRAL ALASKA ON SUNDAY AND MONDAY. THE
OTHER PROBLEM WILL BE THE ALASKA RANGE FROM PASW DOWN TO PAIL ALONG
THE RANGE FOR MODERATE SNOWS SUNDAY THROUGH MONDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES...3AB 5AB 6AB 12B 13A 15
         STORMS...3C
         HEAVY FREEZING SPRAY...12B 13AB 14
FIRE WEATHER...NONE

PROTON MAR 05