Small Craft Advisory 583, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 AM AKDT SUN AUG 4 2013

.ANALYSIS AND UPPER LEVELS...
 A TROUGH AXIS EXTENDS ACROSS SOUTHWEST ALASKA TO THE WESTERN GULF
FROM A STACKED LOW CENTERED NEAR SAINT MATTHEW ISLAND IN THE BERING.
ABUNDANT MOISTURE IS STREAMING AROUND THIS SYSTEM KEEPING LOW AND MID
LEVEL CLOUDS OVER ALASKA AND THE BERING. SCATTERED SHOWER ACTIVITY
CONTINUES THIS MORNING ACROSS MOST OF SOUTHERN ALASKA. A WEAK SURFACE
RIDGE ACROSS SOUTHEASTERN ALASKA IS SUPPRESSING SHOWER ACTIVITY OVER
THE COPPER RIVER BASIN.

.MODEL DISCUSSION...
MODELS ARE IN GOOD AGREEMENT THROUGH MONDAY WITH DEEPENING THE TROUGH
IN THE EASTERN BERING AND THEN BEGIN TO DIVERGE IN SOLUTIONS ON
MONDAY AS A SECONDARY LOW CLOSES OFF SOUTH OF THE ALASKA PENINSULA.
THIS LOW WILL HELP TO MOVE A SURFACE LOW FROM THE NORTH PACIFIC TO
SOUTH OF THE ALASKA PENINSULA LATE MONDAY. THE SURFACE LOW IS
EXPECTED TO TRACK NORTH TOWARD BRISTOL BAY ON TUESDAY AS STRONG RIDGE
BUILDS OVER EASTERN ALASKA. TIMING AND STRENGTH OF THIS SYSTEM SHOULD
BE MONITORED AS MODEL CONFIDENCE IS AVERAGE TO BELOW AVERAGE AT THIS
TIME.

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...
MOSTLY CLOUDY WITH LIGHT SHOWERS WILL CONTINUE THROUGH TUESDAY AS
SHORT WAVES MOVE FROM THE LOW IN THE BERING. GUSTY WINDS ACROSS
TURNAGAIN ARM AND HIGHER ELEVATIONS WILL DIMINISH LATER THIS MORNING
AS THE SURFACE TROUGH WEAKENS IN ACROSS THE SOUTHWEST. THE NEXT STORM
SYSTEM APPROACHES THE WESTERN GULF MONDAY NIGHT BRINGING GUSTY WINDS
TO KODIAK. THIS SYSTEM WILL SPREAD NORTHEAST OVER THE GULF AND KENAI
PENINSULA ON TUESDAY.

SOUTHWEST ALASKA...
THE SURFACE TROUGH OVER SOUTHWEST ALASKA WILL WEAKEN LATER TODAY
DIMINISHING GUSTY WINDS ACROSS BRISTOL BAY AND THE KUSKOKWIM VALLEY.
CLOUDY CONDITIONS WITH RAIN SHOWERS WILL CONTINUE THROUGH TUESDAY AS
WEEK SHORT WAVES MOVE OVER SOUTHWEST ALASKA. PATCHY FOG WILL MAINLY
AFFECT COASTAL LOCATIONS.

ALEUTIANS/BERING SEA...
THE BERING LOW WILL DEEPEN AS IT SHIFTS EASTWARD BRINGING PERIODS OF
RAIN THROUGH TUESDAY. WESTERLY WINDS WILL SHIFT OUT OF THE NORTH AS
THE LOW CENTER MOVES CLOSER TO WESTERN ALASKA. WINDS WILL INCREASE
MONDAY OVER THE WESTERN BERING AND ACROSS THE CENTRAL BERING ON
TUESDAY AS A SURFACE LOW MOVES FROM THE NORTHERN BERING.

.LONG TERM FORECAST...
THE LONG WAVE PATTERN IS PROGGED TO SHIFT SLOWLY EASTWARD THROUGH THE
END OF THE WEEK. MODEL CONFIDENCE IS LOW WEDNESDAY THROUGH SATURDAY
AS MODELS DIFFER IN HANDLING THE LOW CENTERS DURING THE BEGINNING OF
WEEK. A WETTER PATTERN IS EXPECTED WITH A BROAD LONG WAVE PATTERN IN
PLACE.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...150 155.
FIRE WEATHER...NONE.

KH AUG 13