Small Craft Advisory 994, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AST SUN NOV 27 2005

.DISCUSSION...
AN UPPER LEVEL TROUGH WITH AN EMBEDDED CUTOFF LOW OVER THE GULF OF
ALASKA IS BEING PUSHED TO THE EAST BY A RIDGE OVER THE BERING SEA.
THE ASSOCIATED SURFACE LOW IN THE GULF CONTINUES TO MOVE SOUTHEAST.
AS A RESULT THE RAIN AND SNOW SHOWERS THAT HAVE BEEN AFFECTING PRINCE
WILLIAM SOUND ARE SHIFTING SOUTHEAST AS WELL. MOSTLY CLEAR SKIES ARE
DOMINATING OVER THE MAINLAND IN RESPONSE TO HIGH PRESSURE BUILDING
OVER THE INTERIOR. THIS HAS ALLOWED AREAS OF FOG TO DEVELOP OVER
WESTERN ALASKA AND THE MATSU VALLEY. THE INCREASING PRESSURE GRADIENT
BETWEEN THIS HIGH AND THE LOW IN THE GULF IS PROMPTING STRONGER WINDS
IN CHANNELED TERRAIN...MOSTLY IN THE NORTHERN AND WESTERN SOUND. OUT
WEST...AN INTENSE LOW OVER ADAK WITH A FRONT EXTENDING SOUTH ALONG
170W IS MAKING ITS WAY EAST OVER THE CENTRAL ALEUTIANS BRINGING GALE
AND STORM FORCE WINDS TO THE ALEUTIANS AND CENTRAL AND EASTERN BERING
SEA.

PRIMARILY USED THE NAM MODEL FOR THE EASTERN DOMAIN SHORT TERM FOR
ITS SOLUTION AND DETAIL. PREFERRED THE GFS MODEL FOR THE LONG RANGE
AND FOR THE ENTIRE WESTERN DOMAIN PACKAGE FOR ITS INITIALIZATION AND
CONSISTENCY.

THE LOW PRESENTLY IN THE GULF WILL CONTINUE TO MOVE SOUTHEAST OUT OF
OUR AREA BY THIS AFTERNOON WITH A TROUGH REMAINING ALONG THE COAST IN
THE GULF THROUGH TUESDAY. A LOW WILL REDEVELOP TUESDAY IN THE GULF
HELPING TO RETAIN THE PRESSURE GRADIENT TO THE NORTH. THE PRESSURE
GRADIENT BETWEEN THE STRENGTHENING HIGH OVER THE INTERIOR AND BOTH
LOWS WILL ALLOW STRONGER WINDS THROUGH THE TYPICAL GUSTIER
AREAS...WHITTIER...VALDEZ AND THE COPPER RIVER DELTA THROUGH TUESDAY.
IN THE LONG RANGE...A BLOCKING RIDGE BETWEEN THE INTERIOR HIGH AND
ANOTHER HIGH SOUTH OF THE AKPEN WILL TEND TO KEEP CONDITIONS DRY AND
COLD OVER THE MAINLAND.

IN THE WEST...THE LOW OVER ADAK WILL MOVE NORTH THROUGH TODAY WHILE
THE FRONT PUSHES OVER THE CENTRAL AND EASTERN ALEUTIANS. A STRONG
PRESSURE GRADIENT IN ADVANCE OF THE FRONT WILL CONTINUE TO BRING
STORM FORCE WINDS OVER THE ALEUTIANS TODAY AND TONIGHT. WARM AIR
BEING ADVECTED FROM THE SOUTH WILL KEEP MOST OF THE PRECIP AS RAIN.
NOT EXPECTING THIS FRONT TO MAKE IT INTO SOUTH CENTRAL AS IT RUNS
INTO MOUNTAINOUS TERRAIN AND THE ENERGY DROPS. A RIDGE WILL BUILD
OVER THE ALEUTIANS AND BERING SEA ON MONDAY BEFORE ANOTHER SYSTEM
WILL MOVE IN OVER THE WESTERN ALEUTIANS TUESDAY. A LESS INTENSE
SYSTEM THAN THE PREVIOUS...IT SHOULD DISSIPATE OVER THE CENTRAL
ALEUTIANS BY THURSDAY MORNING WITH THE RIDGE BUILDING BACK IN THROUGH
FRIDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALE 170 171 175 176 179 410
      ...STORM 172 180 185 410
FIRE WEATHER...NONE

LR/BL NOV 05