Small Craft Advisory 505, NWS Anchorage, AK

SOUTH CENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 PM AKDT FRI JUL 22 2011

.ANALYSIS AND UPPER LEVELS...
THE UPPER AND SURFACE LOW OVER THE CENTRAL GULF OF ALASKA CONTINUES
MOVE SOUTH TOWARD THE NORTHEAST PACIFIC. ANOTHER UPPER LOW NEAR THE
WESTERN ALEUTIANS CONTINUES TO MOVE INTO THE BERING SEA. AN UPPER
RIDGE OVER WESTERN ALASKA IS STILL MOVING EAST. A STRONG SURFACE LOW
IS VERTICALLY STACKED UNDER THE UPPER LOW NEAR THE WESTERN ALEUTIANS.
THE ASSOCIATED WEATHER FRONT EXTENDS ACROSS THE CENTRAL BERING SEA
AND THROUGH THE EASTERN ALEUTIANS AND IS MOVING CLOUDS OVER THE
YUKON KUSKOKWIM DELTA.

.MODEL DISCUSSION...
MODEL ARE IN VERY GOOD AGREEMENT ON THE MOVEMENT OF THE WESTERN LOW
PRESSURE SYSTEM AND THE FRONT. THE UPPER LOW OVER THE WESTERN BERING
WILL MOVE EAST AND BECOME STATIONARY OVER SOUTHWEST ALASKA SATURDAY
NIGHT. THE LOW OVER THE CENTRAL GULF WILL MOVE INTO THE NORTHEAST
PACIFIC TONIGHT THEN WILL DISSIPATE SOUTHWEST OF QUEEN CHARLOTTE
ISLAND SATURDAY NIGHT. THE RIDGE OVER WESTERN ALASKA WILL MOVE INTO
THE WESTERN GULF AND SOUTH CENTRAL ALASKA TONIGHT THEN BECOME NEARLY
STATIONARY OVER THE EASTERN GULF AND THE CENTRAL GULF COAST SATURDAY
THROUGH SUNDAY. THE WESTERN BERING SEA LOW WILL BEGIN TO TURN EAST
THIS EVENING AND MOVE TO NEAR NUNIVAK ISLAND SATURDAY AFTERNOON THEN
WILL WEAKEN OVER WESTERN ALASKA SATURDAY NIGHT. THE ASSOCIATED FRONT
WILL MOVE INTO THE ALASKA PENINSULA, BRISTOL BAY AND KUSKOKWIM DELTA
TONIGHT AND INTO THE SOUTHWEST INTERIOR AND KODIAK ISLAND SATURDAY
THEN WILL WEAKEN OVER SOUTH CENTRAL ALASKA AND THE EASTERN GULF
SATURDAY NIGHT AND SUNDAY.

.SHORT TERM FORECAST...
SOUTH CENTRAL AND THE GULF...THERMAL TROUGH OVER THE CENTRAL INTERIOR
WILL PRODUCE SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS OVER THE
SUSITNA VALLEY AND THE COPPER RIVER BASIN THIS AFTERNOON AND EVENING.
SATURDAY WILL BE LESS CONVECTIVE WITH SHOWERS DEVELOPING ONLY IN THE
COPPER RIVER BASIN SATURDAY. CLOUDS WILL BE INCREASING FROM THE WEST
WITH RAIN MOVING INTO THE SUSITNA VALLEY AND KENAI PENINSULA LATE
SATURDAY AFTERNOON AND EVENING. RAIN WILL SPREAD INTO THE COPPER
RIVER BASIN AND PRINCE WILLIAM SOUND SATURDAY NIGHT AND SUNDAY.

.SOUTHWEST ALASKA...
THE WEATHER FRONT OVER THE BERING SEA WILL SPREAD RAIN INTO SOUTHWEST
ALASKA AND THE ALASKA PENINSULA TONIGHT AND SATURDAY THEN CHANGE TO
SHOWERS SATURDAY NIGHT AND AND SUNDAY.

.BERING SEA...
RAIN OVER THE EASTERN ALEUTIANS WILL BECOME SHOWERS TONIGHT. GALE
FORCE WINDS OVER THE WESTERN AND CENTRAL ALEUTIANS WILL MOVE INTO THE
EASTERN ALEUTIANS SATURDAY THEN DIMINISH SATURDAY NIGHT.

.LONG TERM FORECAST...
THE UPPER LOW OVER SOUTHWEST ALASKA SUNDAY WILL SLOWLY WEAKEN OVER
WESTERN ALASKA THROUGH TUESDAY. MOSTLY CLOUDY SKIES AND SHOWERS WILL
REMAIN OVER THE SOUTHERN MAINLAND INTO THE BEGINNING OF NEXT WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...155 165 170 172 175 176 179
FIRE WEATHER...FIRE WEATHER WATCH FOR THE COPPER RVR BASIN SATURDAY

NM JUL 11