Small Craft Advisory 787, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM ADT SUN SEP 23 2007

.MODEL DISCUSSION...
MODELS ARE IN GOOD AGREEMENT OVER THE GULF OF ALASKA AND MAINLAND
ALASKA THROUGH TUESDAY NIGHT, BUT THEY DIVERGE A BIT OVER THE BERING
SEA. THOUGH BOTH NAM AND GFS INITIALIZES ABOUT THE SAME, THE LOW
CENTER OF THE NAM IS ABOUT 150 NM WEST OF THE GFS BY 12Z MON. THEN
THE SOLUTIONS SLOWLY CONVERGE AS BOTH MODELS MOVE THE LOW NEAR SAINT
LAWRENCE ISLAND BY TUE NIGHT. GFS IS THE PREFERRED SOLUTION SINCE IT
HAS BETTER RUN-TO-RUN CONSISTENCY.

.ANALYSIS AND UPPER LEVELS...
THE UPPER SHORT WAVE OVER THE GULF CONTINUES TO MOVE EAST WITH THE
LOW PRESSURE CENTER BENEATH IT. MOST OF THE RAIN ASSOCIATED WITH THIS
SYSTEM REMAIN ALONG THE CENTRAL GULF COAST WITH SOME LIGHT
PRECIPITATION OVER THE COPPER RIVER BASIN. STRONG WINDS OVER KODIAK
ISLAND AND THROUGH CHANNELED TERRAIN ALONG THE KENAI AND CHUGACH
MOUNTAINS WILL DIMINISH THIS AFTERNOON AND EVENING AS THE STORM
WEAKENS AND CONTINUES TO MOVE EAST.

THE LARGE INTENSE LOW SLOWLY MOVING NORTHEAST ACROSS THE BERING SEA
GENERATED MOSTLY GALE FORCE WINDS THROUGH THE ALEUTIAN CHAIN WITH
SOME AREAS OF STORM FORCE WINDS WEST OF ADAK THIS MORNING. ITS
WEATHER FRONT WILL MOVE ONSHORE OVER THE KUSKOKWIM DELTA THIS
AFTERNOON.

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...
THE LOW IN THE CENTRAL GULF WILL TURN NORTHEAST TONIGHT AND MOVE
INLAND JUST WEST OF YAKUTAT BAY MONDAY MORNING. RAIN OVER PRINCE
WILLIAM SOUND WILL DIMINISH THIS EVENING. A WEAK WEATHER FRONT,
ASSOCIATED WITH THE BERING SEA LOW, WILL MOVE INTO THE SUSITNA VALLEY
AND COOK INLET MONDAY MORNING AND SLOWLY MOVE THROUGH THE REST OF
SOUTHCENTRAL ALASKA AND THE GULF OF ALASKA THROUGH TUESDAY. PERIODS
OF LIGHT RAIN WILL MOVE INTO THE REGION FROM THE WEST EARLY MONDAY
AND SPREAD TO THE COPPER RIVER BASIN MONDAY NIGHT.

SOUTHWEST ALASKA...
THE WEATHER FRONT ALONG THE SOUTHWEST COAST WILL CONTINUE TO PUSH
EAST INTO THE REST OF SOUTHWEST ALASKA TONIGHT. RAIN WILL MOVE INLAND
FROM THE COAST TONIGHT. SOUTHWEST FLOW BEHIND THE FRONT WILL KEEP THE
CLOUDS AND SHOWERS OVER THE REGION INTO MONDAY.

AN UPPER SHORT WAVE SOUTH OF THE WESTERN ALEUTIANS WILL RAPIDLY MOVE
UP AROUND THE UPPER LOW CENTER INTO THE KUSKOKWIM DELTA MONDAY
AFTERNOON AN INTO THE SOUTHWEST INTERIOR MONDAY EVENING. MORE RAIN
WILL MOVE THE AREA FROM LATE MONDAY AFTERNOON THROUGH MONDAY NIGHT
WITH SHOWERS PERSISTING INTO TUESDAY.

BERING SEA AND ALEUTIANS...
THE 965 MB LOW OVER THE CENTRAL BERING SEA WILL MOVE TO NEAT SAINT
LAWRENCE ISLAND TUESDAY AFTERNOON. A LARGE AREA OF GALE FORCE WINDS
AND RAIN WILL PERSIST OVER THE THE ALEUTIANS AND THE SOUTHERN BERING
SEA TONIGHT THROUGH TUESDAY.

.LONG TERM FORECAST...
THE EASTERLY PROGRESSION OF THE SYSTEM WILL CONTINUE THE REST OF THIS
WEEK. THE UPPER LOW NEAR SAINT LAWRENCE ISLAND WILL DISSIPATE OVER
NORTON SOUND WEDNESDAY NIGHT. AN UPPER RIDGE WILL ENTER THE SOUTHWEST
BERING SEA WEDNESDAY NIGHT MOVE INTO WESTERN ALASKA THURSDAY AND INTO
WESTERN CANADA FRIDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 170, 172, 175, 176, 179, 185
FIRE WEATHER...NONE.

NM SEP 07