Small Craft Advisory 345, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM ADT THU APR 12 2007

.MODEL DISCUSSION...
THE CURRENT SET OF MODELS ARE IN VERY GOOD THROUGH SUNDAY AFTERNOON.
IT LOOKS LIKE BOTH GFS AND NAM HAVE LOCKED ONTO THE SAME SOLUTION,
THOUGH THERE STILL SMALL DIFFERENCES IN THE STORM DEPTH AND POSITION
AFTER SATURDAY AFTERNOON.

.ANALYSIS AND UPPER LEVELS...
THE MAIN FEATURE ON THE 500 MB CHART IS A MODERATE LOW SOUTH OF THE
WESTERN GULF WHICH WILL MOVE EAST AND WEAKEN INTO A TROUGH OVER THE
EASTERN GULF FRIDAY NIGHT. ANOTHER UPPER LOW NORTH OF THE CHUKCHI SEA
WILL DRIFT SOUTH INTO THE CHUKCHI SEA SATURDAY AFTERNOON. OTHERWISE
THE HIGH FIELD IS OVER MAINLAND ALASKA IS RELATIVELY FLAT.

AT THE SURFACE, A MODERATE LOW SOUTH OF KODIAK IS VERTICALLY STACKED
BENEATH THE UPPER LOW. A FLAT PRESSURE PATTERN PERSISTS OVER MAINLAND
ALASKA.

.SHORT TERM FORECAST...

IN THE EAST, THE MAIN LOW 400 MILES SOUTH OF KODIAK WILL MOVE EAST
AND WILL DISSIPATE ABOUT 200 MILES SOUTH OF SITKA SATURDAY. THE
ASSOCIATED FRONT OVER THE SOUTHERN GULF WILL WEAKEN AS IT SWINGS INTO
THE NORTHEASTERN GULF TONIGHT AND WILL DISSIPATE OVER PRINCE WILLIAM
SOUND FRIDAY AFTERNOON AND EVENING. GALE FORCE WINDS OVER THE WESTERN
GULF THIS AFTERNOON WILL WEAKEN THROUGH TONIGHT. AREAS OF
PRECIPITATION WILL SPREAD INTO EASTERN PRINCE WILLIAM SOUND AND THE
COPPER RIVER BASIN FRIDAY AND WILL BECOME SHOWERS AS IT CONTINUES TO
MOVE WEST INTO THE REST OF THE SOUND AND EASTERN KENAI PENINSULA
FRIDAY NIGHT AND SATURDAY.

IN THE WEST, AN UPPER TROUGH FORMING OVER THE SOUTHWEST INTERIOR
FRIDAY EVENING WILL CREATE SCATTERED SHOWERS OVER THE AREA FRIDAY
NIGHT AND SATURDAY.

THE NEXT LOW DEVELOPING OVER THE NORTHWEST PACIFIC WILL RAPIDLY
STRENGTHEN TO 962 MB 250 MILES SOUTHEAST OF DUTCH HARBOR SATURDAY
AFTERNOON. GALE FORCE WINDS AND RAIN WILL MOVE INTO THE EASTERN
ALEUTIANS AND THE ALASKA PENINSULA SATURDAY AND WILL SPREAD TO THE
ALASKA PENINSULA SATURDAY NIGHT.

.LONG TERM FORECAST...
THE 996 MB LOW SOUTH OF THE ALASKA PENINSULA SATURDAY NIGHT WILL MOVE
WILL GRADUALLY WEAKEN AND TURN NORTHEAST INTO THE EASTERN GULF MONDAY
NIGHT. A SECONDARY LOW WILL DEVELOP OVER THE WESTERN GULF SUNDAY
AFTERNOON AND MOVE NORTHWEST INTO THE LOWER COOK INLET MONDAY
AFTERNOON.

MORE SHOWER ARE EXPECTED TO DEVELOP OVER SOUTHERN ALASKA SUNDAY AND
MONDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES 120, 130, 132, 138 AND 150.
FIRE WEATHER...NONE.

NM APR 07