Small Craft Advisory 260, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
100 PM AST SAT MAR 26 2005

.DISCUSSION...UPPER LEVEL LOW OVER BRISTOL BAY WITH A SHORT WAVE
ROTATING INTO THE GULF OF ALASKA. THIS SHORT WAVE SPLITTING OVER THE
GULF WITH A PIECE OF ENERGY TO SLIP NORTH AND ANOTHER TO SLIP ACROSS
THE GULF. ANOTHER SHORT WAVE ROTATING AROUND THE UPPER LEVEL LOW FROM
THE CENTRAL BERING INTO THE GULF SUNDAY. THEN ANOTHER SHOOTS OUT OF
THE KAMCHATKA UPPER LOW SUNDAY ACROSS THE ALEUTIANS AND INTO SOUTHERN
GULF BY MONDAY MORNING. THE JET IS ORIENTED ALONG 50N DURING THIS
PERIOD. JET BECOMES BUCKLED NEAR 180 AS THE KAMCHATKA LOW MOVES EAST
AND THE POLAR LOW DROPS INTO THE BERING STRAIT MONDAY. THIS ALL
CONSOLIDATES NEAR 160W BY WEDNESDAY MORNING AS THE LOW CURRENTLY IN
BRISTOL BAY LIFTS THROUGH THE INTERIOR. THE POLAR LOW DIGS INTO THE
GULF THROUGH THE END OF THE WEEK THEN WEAKENS. IN THE MEANTIME...A
RIDGE TRAVERSES THE ALEUTIANS BEHIND THE EXITING KAMCHATKA LOW.
ANOTHER LOW MOVES INTO THE KAMCHATKA BY WEDNESDAY MORNING WITH THE
RIDGE OVER THE BERING SEA.

GENERAL PLACEMENT OF THE UPPER LEVEL POSITIONS IN GOOD AGREEMENT WITH
ALL MODELS. MODELS IN GOOD AGREEMENT AT THE SURFACE OVER THE ALEUTIAN
CHAIN. THE DETAILS OF EACH SHORT WAVE AND ITS ASSOCIATED SURFACE LOW
OVER THE GULF OF ALASKA AND SOUTH CENTRAL ALASKA ARE SLIGHTLY
DIFFERENT BETWEEN THE NAM AND GFS. THE EUROPEAN MODELS DIFFER
SLIGHTLY AS WELL. THE PROBLEMS ARISE FROM THE SPEED AND INTENSITY OF
EACH SHORT WAVE ROTATING AROUND THE UPPER LEVEL LOW OVER SOUTHWEST
ALASKA. THE MODELS DO LINE UP A BIT BETTER WITH THE 18Z RUN OF THE
NAM AND 12Z RUN OF THE GFS. EITHER WAY THE BIG PICTURE IS THE SURFACE
LOW IN THE GULF TO MOVE NEAR MIDDLETON ISLAND BY SUNDAY MORNING AND
INLAND SUNDAY. THE MOISTURE TO WRAP AROUND THIS FEATURE. OVERRUNNING
PRECIP TO PUSH OVER SOUTH CENTRAL AS A RESULT. PRECIP FROM THE MODELS
NOT ALL THAT IMPRESSIVE. IT WILL SNOW...BUT DO NOT ANTICIPATE AT THIS
TIME TO REACH ADVISORY LEVEL. DO EXPECT SCATTERED SHOWERS TO LAST
OVER MUCH OF SOUTH CENTRAL THROUGH MID WEEK AT LEAST DUE TO THE
UNSTABLE NATURE OF THE AIR MASS. AIR MASS UNSTABLE AS A RESULT OF THE
PLACEMENT OF THE UPPER LEVEL LOWS AND COLD AIR ALOFT. THE CURRENT
UPPER LOW TO LIFT NORTH MONDAY/TUESDAY AS THE POLAR LOW DROPS INTO
THE BERING STRAIT AND OVER WESTERN ALASKA TUESDAY. PIECE OF THE
KAMCHATKA LOW TO MOVE INTO THE GULF TUESDAY AND WRAP UP INTO THE
NORTHERN GULF COAST WEDNESDAY.

FRONT MOVING ACROSS THE CENTRAL BERING SEA AND CENTRAL ALEUTIAN CHAIN
TODAY BRINGING MODERATE TO STRONG WINDS TO THE AREA. THESE WINDS TO
SHIFT INTO THE EASTERN BERING AND ALEUTIAN CHAIN TONIGHT AND INTO THE
GULF SUNDAY. A SURFACE LOW DEVELOPS ALONG THIS FRONT NEAR DUTCH THIS
AFTERNOON AND ACROSS BRISTOL BAY TONIGHT. PLENTY OF PRECIP WITH THIS
FEATURE AS WELL. IN ADDITION...PLENTY OF PRECIP WRAPPED INTO UPPER
LEVEL LOW OVER THE KUSKOKWIM VALLEY AND MOUNTAINS OF BRISTOL BAY.
MOISTURE TO CONTINUE TO WRAP AROUND THE UPPER LEVEL LOW AND WORK INTO
THE KUSKOKWIM DELTA SUNDAY. ANOTHER WAVE TO WORK ACROSS THE ALEUTIAN
CHAIN SUNDAY WITH MODERATE WINDS. THE KAMCHATKA LOW IS FORCED EAST
SUNDAY AFTERNOON AS A LOW MOVES OUT OF EAST ASIA. THE OLD KAMCHATKA
LOW MOVES ACROSS THE ALEUTIAN CHAIN THROUGH MONDAY/TUESDAY AND INTO
THE GULF TUESDAY NIGHT. RIDGE TO BUILD OVER WESTERN ALEUTIAN BY
TUESDAY NIGHT AND INTO THE CENTRAL BERING WEDNESDAY. A STRONG FRONT
TO ENTER THE WESTERN ALEUTIAN CHAIN WEDNESDAY AS THE LOW DEEPENS NEAR
KAMCHATKA.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...HEAVY FREEZING SPRAY 8 14
         STORM 12A
         GALE 3A 5A 5B 12A1 12B 13A 13B
FIRE WEATHER...NONE

JN MAR 05