Small Craft Advisory 356, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM ADT SUN APR 15 2007

.MODEL DISCUSSION...
THE MODELS ARE IN FAIRLY GOOD AGREEMENT OF THE EVOLUTION IF THE
COMPLEX LOW PRESSURE SYSTEM IN AND SOUTH OF THE GULF OF ALASKA
THROUGH TUESDAY AFTERNOON. OUT IN THE WEST...THERE STILL ENOUGH
RUN-TO-RUN INCONSISTENCIES OF THE MULTI-CENTERED SYSTEM APPROACHING
THE ALEUTIANS THAT CONFIDENCE IN ANY PARTICULAR MODEL IS ON THE LOW
SIDE. THE MAIN PROBLEM IS THAT THE MODELS CANNOT DECIDE WHICH OF THE
TWO LOWS THAT MAKE UP THIS COMPLEX SYSTEM WILL BE STRONGER OR WILL
THEY MERGE INTO A SINGLE-CENTERED SYSTEM.

.ANALYSIS AND UPPER LEVELS...
SATELLITE IMAGES SHOW A LOW PRESSURE CENTER IN THE NORTH CENTRAL GULF
OF ALASKA WITH A WEAKENING FRONT ALONG THE CENTRAL GULF COAST. THE
PARENT LOW IS JUST SOUTH OF 50N LATITUDE AND IS STILL MOVING EAST.

AT THE UPPER LEVELS...THE UPPER LOW ASSOCIATED WITH THE SYSTEM IN THE
GULF CONTINUES TO WEAKEN. ANOTHER UPPER LOW OVER THE CHUKOTSK
PENINSULA IS BECOMING THE DOMINANT SYSTEM IN THE REGION.

.SHORT TERM FORECAST...
SOUTHCENTRAL AK AND THE GULF...
A WEAKENING LOW IN THE NORTHERN WILL REMAIN NEARLY STATIONARY AND
DISSIPATE MONDAY MORNING. THE FRONT ALONG THE CENTRAL GULF COAST WILL
DISSIPATE BY THIS EVENING. AREAS OF RAIN OVER THE GULF OF ALASKA AND
ALONG THE CENTRAL GULF COAST AND KENAI PENINSULA WILL BECOME SHOWERS
THIS EVENING. THE SHOWERS WILL DIMINISH MONDAY NIGHT AS BOTH AN UPPER
AND SURFACE RIDGE MOVES INTO THE GULF.

SOUTHWEST ALASKA...
THE NORTHERLY FLOW WILL DIMINISH AS A DEFAULT AHEAD OF THE NEXT STORM
SYSTEM MOVES INTO THE AREA MONDAY. A WEATHER FRONT WILL MOVE INTO
BRISTOL BAY MONDAY NIGHT AND WILL MOVE NORTHEAST INTO THE SOUTHWEST
INTERIOR TUESDAY. SNOW AND WIND WILL MOVE INTO AREA AHEAD OF THE
FRONT.

BERING SEA AND ALEUTIANS...
A 988 MB 550 MILES SOUTH OF SHEMYA WILL MOVE TO 100 MILES NORTHEAST
OF ADAK MONDAY EVENING AND TO NEAR SAINT PAUL ISLAND TUESDAY
AFTERNOON. ANOTHER LOW OVER THE NORTH PACIFIC WILL MOVE NORTHEAST AND
STRENGTHEN TO 150 MILES EAST OF DUTCH HARBOR TUESDAY AFTERNOON. RAIN
AND GALE FORCE WINDS WILL MOVE INTO THE CENTRAL ALEUTIANS TONIGHT AND
SPREAD TO THE EASTERN ALEUTIAN MONDAY AND INTO THE ALASKA PENINSULA
MONDAY NIGHT.

.LONG TERM FORECAST...
UNCERTAINLY OF THE MODEL STABILITY AND CONSISTENCY CASTS SOME DOUBT
ON THE PROGRESSION OF THE NEXT STORM. THOUGH IT DOES LOOK LIKE THE
STORM WILL TRACK EAST, SOUTH OF THE ALEUTIAN CHAIN.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 170, 172, 175, 176 AND 179.
FIRE WEATHER...NONE.

NM APR 07