Small Craft Advisory 783, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM ADT SAT SEP 22 2007

.MODEL DISCUSSION...
MODELS CONTINUE TO BE IN GOOD AGREEMENT THROUGH MONDAY AFTERNOON,
THOUGH THE NAM MOVES THE LOW IN THE GULF ONSHORE NEAR SITKA WHILE THE
GFS TAKE IT INLAND A LITTLE FURTHER NORTH NEAR GUSTAVUS MONDAY
MORNING. THIS DIFFERENCE SHOULD HAVE VERY LITTLE IMPACT ON THE
FORECASTS.

.ANALYSIS AND UPPER LEVELS...

THE UPPER AIR SYSTEMS HAVE CONTINUED TO MOVE EAST SINCE YESTERDAY
WITH THE UPPER RIDGE OVER THE WESTERN MAINLAND AND A NEW UPPER LOW
OVER THE KAMCHATKA PENINSULA MOVING TOWARD THE BERING SEA. A SHORT
WAVE OVER THE ALASKA PENINSULA MIRRORS THE SURFACE LOW SOUTH OF COLD
BAY.

AT THE SURFACE, THE MAIN LOW PRESSURE SYSTEMS ARE CLOSELY RELATED
WITH THE UPPER FEATURES AND WILL MOVE EAST WITH THEM.

.SHORT TERM FORECAST...
UPPER AIR.
THE UPPER SHORT WAVE NEAR COLD BAY WILL MOVE EAST INTO THE GULF OF
ALASKA TONIGHT AND INTO SOUTHEAST ALASKA SUNDAY NIGHT. THE UPPER
RIDGE OVER WESTERN ALASKA WILL FLATTEN AS IT RUNS INTO THE STATIONARY
LOW OVER NORTHWEST CANADA SUNDAY. THE OTHER UPPER LOW EAST OF
KAMCHATKA WILL MOVE INTO THE NORTH CENTRAL BERING SEA MONDAY
AFTERNOON.

SOUTHCENTRAL.
MODELS ARE STILL MOVING THE LOW PRESSURE SYSTEM, SOUTH OF THE ALASKA
PENINSULA, INTO THE WESTERN GULF OF ALASKA TONIGHT THEN EAST INTO
NORTHERN SOUTHEAST ALASKA MONDAY MORNING. THE AREA OF LIKELY
PRECIPITATION IS CONFINED TO KODIAK ISLAND, THE SOUTHERN KENAI
PENINSULA AND ALONG THE CENTRAL GULF COAST TONIGHT AND SUNDAY. GALE
FORCE WINDS WILL MOVE INTO THE WESTERN GULF AND KODIAK ISLAND WATERS
THIS EVENING AND MOVE INTO THE WATERS ALONG THE CENTRAL GULF COAST
SUNDAY MORNING. WINDS WILL DIMINISH SUNDAY EVENING. OTHERWISE MORE
MID TO HIGH LEVEL CLOUDINESS WILL MOVE INTO SOUTHCENTRAL ALASKA
TONIGHT.

A WEAK WEATHER FRONT ASSOCIATED WITH A STORM IN THE BERING SEA WILL
MOVE INTO THE SUSITNA VALLEY AND COOK INLET LATE MONDAY. RAIN IS
EXPECTED FOR THE SUSITNA AND MATANUSKA VALLEYS, KENAI PENINSULA AND
ANCHORAGE LATE MONDAY AFTERNOON AND EVENING.

SOUTHWEST ALASKA.
THE AREAS OF RAIN ASSOCIATED WITH THE LOW PRESSURE SYSTEM SOUTH OF
THE ALASKA PENINSULA APPEARS TO BE SMALLER THAN ORIGINALLY PROGGED
FOR. MOST OF IT IS EXPECTED TO MOVE THROUGH BRISTOL BAY TONIGHT AND
TAPER TO SHOWERS SUNDAY.

THE WEATHER FRONT ASSOCIATED WITH THE BERING SEA LOW WILL MOVE INTO
THE SOUTHWEST COAST SUNDAY EVENING. RAIN WILL MOVE KUSKOKWIM DELTA
LATE SUNDAY AFTERNOON AND WILL SPREAD TO THE REST OF THE AREA SUNDAY
NIGHT.

BERING SEA AND ALEUTIANS.
A STRONG STORM SYSTEM EAST OF THE KAMCHATKA PENINSULA WILL MOVE INTO
THE NORTH CENTRAL BERING SEA MONDAY. RAIN AND GALE FORCE WINDS OVER
THE WESTERN ALEUTIANS WILL SPREAD INTO THE CENTRAL ALEUTIANS TONIGHT
AND INTO THE EASTERN ALEUTIANS SUNDAY.

.LONG TERM FORECAST...
BOTH UPPER AND SURFACE LOW OVER THE BERING SEA WILL DRIFT INTO THE
YUKON-KUSKOKWIM DELTA WEDNESDAY. THIS WILL KEEP SOUTHWEST ALASKA
UNDER A PERSISTENT MOIST SOUTHWEST FLOW INTO WEDNESDAY. CLOUDS AND
SHOWERS WILL REMAIN OVER THE AREA IN THE THE MIDDLE OF THE WEEK.

RAIN OVER MOST OF SOUTHCENTRAL ALASKA MONDAY NIGHT WILL BECOME
SHOWERS TUESDAY AND WEDNESDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORM..176
         GALE..120, 130, 132, 138, 155, 170, 172, 175, 185.
FIRE WEATHER...NONE.

NM SEP 07