Small Craft Advisory 903, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM AKST MON NOV 17 2008

.MODEL DISCUSSION...
MODELS ARE IN GENERALLY GOOD AGREEMENT OVER MAINLAND ALASKA AND THE
BERING SEA THROUGH WEDNESDAY NIGHT BUT CANNOT COME TO ANY CLEAR
CONSENSUS OVER THE GULF OF ALASKA TUESDAY AFTERNOON. RUN-TO-RUN
CONTINUITY OF THE DEVELOPMENT OF THE COMPLEX LOW PRESSURE SYSTEM
SOUTH OF THE GULF HAS BEEN POOR WITH ALL THE MODELS. SO CONFIDENCE
BEYOND THE FIRST 36 HOURS OVER THE GULF REMAIN FAIRLY LOW.

.ANALYSIS AND UPPER LEVELS...
A UPPER SHORTWAVE TROUGH OVER THE TANANA VALLEY CONTINUES TO MOVE
EAST. A UPPER RIDGE OVER THE WESTERN BERING CONTINUES TO BUILD
EASTWARD.

AT THE SURFACE...A LARGE COMPLEX LOW SOUTH OF THE ALASKA PENINSULA
CONTINUES TO MOVE EAST. A LARGE AREA OF HIGH PRESSURE OVER SIBERIA
WILL CONTINUE TO BUILD SOUTH AND EAST INTO THE BERING SEA AND
NORTHWEST ALASKA THROUGH THIS EVENING.

.SHORT TERM FORECAST...
A RIDGE OF HIGH PRESSURE OVER NORTHERN ALASKA WILL SPREAD SOUTHWARD
INTO THE SOUTHERN INTERIOR TUESDAY AND WEDNESDAY. THE COMPLEX LOW
PRESSURE SYSTEM, WITH MULTIPLE LOWS REVOLVING AROUND A COMMON CENTER,
SOUTH OF THE ALASKA PENINSULA WILL MOVE EAST AND BECOME STATIONARY
SOUTH OF THE GULF TUESDAY. COLD DRY AIR OVER THE NORTHERN INTERIOR
WILL SPREAD SOUTH INTO THE SOUTHERN MAINLAND TONIGHT AND TUESDAY.
AREAS OF LOW CLOUDS AND FOG WILL PERSIST IN SOME LOW LYING AREAS
THROUGH TONIGHT BUT SHOULD DISSIPATED TUESDAY.

THE PRESSURE GRADIENT OVER THE NORTHERN GULF, ALONG THE GULF COAST
AND KODIAK ISLAND WILL GRADUALLY INTENSIFY THROUGH WEDNESDAY NIGHT.
STRONG NORTH AND WEST WINDS WILL DEVELOP THROUGH CHANNELED TERRAIN
ALONG THE GULF COAST AND THROUGH SOME OF THE PASSES ALONG THE ALASKA
RANGE.

A MODERATE LOW SOUTHWEST OF ATTU WILL MOVE SOUTHWEST INTO THE NORTH
PACIFIC TUESDAY. THE RIDGE OVER THE CENTRAL BERING SEA WILL CONTINUE
TO BUILD INTO TUESDAY THEN WILL BE DISPLACED INTO THE EASTERN BERING
BY A STRONG STORM SYSTEM MOVING UP THE EAST COAST OF THE KAMCHATKA
PENINSULA WEDNESDAY. GALE FORCE WINDS OVER THE WESTERN ALEUTIANS WILL
DIMINISH LATE TUESDAY, BUT WILL INCREASE TO STORM FORCE WINDS
WEDNESDAY.

.LONG TERM FORECAST...
THE LONG RANGE MODELS CONTINUE TO HAVE VERY DIVERGENT SOLUTIONS, SO
CONFIDENCE REMAINS FAIRLY LOW

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 120, 130, 132, 176
FIRE WEATHER...NONE.

NM NOV 08