Small Craft Advisory 449, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKDT FRI MAY 31 2013

.ANALYSIS AND UPPER LEVELS...
AN UPPER LEVEL HIGH IS OVER CENTRAL ALASKA WITH A THERMAL LOW AT THE
SURFACE. THE UPPER HIGH CONTINUES WEST INTO THE BERING SEA AND
EASTWARD INTO CANADA. AN UPPER LEVEL LOW IS SOUTH OF THE ALEUTIANS
WITH A TROUGH EXTENDING EASTWARD INTO THE GULF OF ALASKA.

.MODEL DISCUSSION...
THE FORECAST MODELS HAVE A GOOD HANDLE ON THE WEATHER SITUATION AND
ARE IN GOOD AGREEMENT THROUGH 84 HOURS. FOR THE AFTERNOON PACKAGE
THERE IS A PREFERENCE TOWARD THE NAM EARLY ON...THEN TRANSITIONING
TO THE GFS.

.SHORT TERM FORECAST...
THE CENTRAL ALASKA RIDGE WILL SLOWLY MOVE NORTH OVER THE NEXT FEW
DAYS. AT THE SAME TIME THE LOW SOUTH OF THE ALEUTIANS WILL SLOWLY
WORK ITS WAY TOWARDS THE GULF OF ALASKA. THE LOW WILL TAKE MOVE MORE
AGGRESSIVELY INTO THE GULF ON MONDAY AS THE CENTRAL ALASKA RIDGE
WEAKENS AND BEGINS TO SPLIT.

THE GENERAL TREND THROUGH THE WEEKEND WILL BE A TRANSITION TO A
COOLER AND MOISTER PATTERN OVER SOUTHERN ALASKA. THE BEST CHANCES
FOR RAIN OVER SOUTH CENTRAL ALASKA WILL BE SATURDAY NIGHT INTO
SUNDAY AS A FRONT DEVELOPS OVER THE AREA ALONG THE MAIN TRANSITION
FROM ANTICYCLONIC TO CYCLONIC FLOW ALOFT.

SOME DIURNAL THUNDERSTORMS ARE POSSIBLE FROM THE LOWER KUSKOKWIM
VALLEY EASTWARD ALONG THE ALASKA RANGE AND INTO THE WRANGLE
MOUNTAINS THROUGH SATURDAY EVENING. BY SUNDAY THE STABLE AIR WILL
HAVE WORKED ITS WAY FAR ENOUGH NORTH TO BRING THE CHANCES OF THUNDER
TO AN END.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...FLOOD WATCH 145.
MARINE...NONE.
FIRE WEATHER...NONE.

LUDWIG MAY 13