Small Craft Advisory 396, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKDT WED MAY 8 2013

.ANALYSIS AND UPPER LEVELS...
THERE IS AN UPPER LEVEL RIDGE OVER THE BERING SEA AND ANOTHER OVER
THE GULF OF ALASKA. THERE IS A WEAK LOW ALONG THE WEST COAST OF
ALASKA CENTERED JUST SOUTH OF NORTON SOUND. A SHORT-WAVE TROUGH OVER
NORTHEAST ALASKA IS MOVING EAST IN THE POLAR JET AND WILL NOT BE A
FACTOR IN THE FORECAST FOR SOUTHERN ALASKA. THERE IS A LOW IN THE
NORTH PACIFIC CENTERED NEAR 50 DEGREES NORTH LATITUDE AND 160
DEGREES WEST LONGITUDE THAT IS PUSHING A FRONT INTO THE EASTERN
ALEUTIANS AND ALASKA PENINSULA.

.MODEL DISCUSSION...
NUMERICAL GUIDANCE IS IN FAIRLY GOOD AGREEMENT TODAY. THE GFS AND
NAM ARE A LITTLE SLOWER AND WEAKER WITH THE SYSTEM DUE IN FRIDAY
NIGHT/SATURDAY THAN THE THE OTHER MODELS (ECMWF...GEM...UKMET) WITH
THE ECMWF THE MOST AGGRESSIVE OF THE BUNCH. THE AFTERNOON FORECASTS
GENERALLY FOLLOW THE NAM/GFS...ALBEIT WITH SOME COMPROMISE TOWARD
THE ECMWF FOR THE FRIDAY NIGHT/SATURDAY SYSTEM.

.SHORT TERM FORECAST...
FOR SOUTH CENTRAL ALASKA...THE GULF RIDGE WILL BUILD NORTHWARD INTO
SOUTH CENTRAL ALASKA TONIGHT AND REMAIN OVER THE AREA INTO FRIDAY
NIGHT. TONIGHT CONDITIONS WILL BE FAIRLY CLEAR AS THE RIDGE BUILDS.
ON THURSDAY THERE WILL BE AN INCREASE IN HIGH CLOUDS AS THE RIDGE
AXIS MOVES NORTH...BUT TEMPERATURES WILL CONTINUE TO WARM. ON FRIDAY
NIGHT AND SATURDAY A SYSTEM WILL PUSH INTO THE AREA FROM THE
SOUTHEAST. THIS SYSTEM WILL BE FAIRLY WEAK AS THE FLOW ALOFT WILL
STILL BE SOMEWHAT ANTICYCLONIC. THIS WILL KEEP MOST OF THE
PRECIPITATION ALONG THE COAST...BUT SOME SHOULD GET INLAND AS WELL.

FOR SOUTHWEST ALASKA...SOME MOISTURE AND EVEN SLIGHT CHANCES OF
PRECIPITATION ARE EXPECTED OVER THE NEXT COUPLE OF DAYS AS THE
SOUTHWEST IS NOT SO STRONGLY UNDER THE RIDGE AND THE WEAK LOW ALONG
THE COAST IS KEEPING FLOW ALOFT SOUTHERLY. HEIGHTS WILL RISE ENOUGH
TO BRING WARMER TEMPERATURES...MAINLY TO THE BRISTOL BAY AREA. ON
SATURDAY THE WEST COAST LOW WILL BE REINVIGORATED BY A SHOT OF COLD
AIR FROM THE POLAR JET AND WILL MOVE SOUTH INTO THE ALASKA PENINSULA
BY AFTERNOON. THIS WILL COMBINE WITH THE SYSTEM MOVING IN FROM SOUTH
CENTRAL ALASKA TO BRING BETTER CHANCES OF PRECIPITATION TO THE AREA.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING 150 170.
FIRE WEATHER...NONE.

LUDWIG MAY 13