Small Craft Advisory 744, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AKDT SAT SEP 27 2008

.MODEL DISCUSSION...
NUMERICAL MODELS CONTINUE TO STRUGGLE WITH THE FORECAST BEYOND ABOUT
THREE DAYS. TOOK A MIDDLE OF THE ROAD APPROACH FOR THE EXTENDED
PORTION OF THE FORECAST AS THE MODELS AGREE ON THE GENERAL PATTERN
BUT DISAGREE ON THE (IMPORTANT) DETAILS.

.ANALYSIS AND UPPER LEVELS...
UPPER POLAR LOW CENTERED ALONG THE ARCTIC SHORE JUST EAST OF BARROW
WITH A TROUGH EXTENDING SOUTH INTO SOUTH CENTRAL ALASKA. ANOTHER LOW
IN THE WESTERN GULF IS ACCELERATING SOUTHEAST AS THE POLAR LOW HELPS
TO EJECT IT OUT. BLOCKING RIDGE OVER THE CENTRAL BERING SEA.

.SHORT TERM FORECAST...
THE POLAR LOW WILL CONTINUE TO MOVE SOUTH TODAY AND WILL BE CENTERED
IN JUST ABOUT THE MIDDLE OF ALASKA BY THIS EVENING. THEN IT WILL
BEGIN TO MOVE EAST TO THE YUKON BORDER BY SUNDAY AFTERNOON. THIS IS
PUSHING COLDER AIR SOUTHWARD...MAINLY INTO SOUTHWEST ALASKA. SOME
SEEPAGE EXPECTED INTO SOUTH CENTRAL AS WELL...MAINLY LATER IN THE
WEEKEND. NOT A LOT OF MOISTURE TO WORK WITH AS FLOW IS MAINLY FROM
THE NORTH SO PRECIPITATION IS SOMEWHAT SPARSE. THE EXCEPTION IS FROM
CORDOVA EASTWARD WHERE RAIN SHOULD CONTINUE THROUGH THE EVENING
BEFORE THE SOUTHERLY FLOW AHEAD OF THE TROUGH PUSHES EAST OF THE
AREA TONIGHT.

.LONG TERM FORECAST...
BY MONDAY THE POLAR LOW WILL BE MOVING EAST OF ALASKA. FLOW ALOFT
WILL BECOME MORE SOUTHWESTERLY THROUGH MID WEEK AS THE BLOCKING
RIDGE BECOMES PINCHED OFF TO THE NORTH AND JET ENERGY BEGINS TO
PUSH UNDERNEATH IT INTO THE STATE. DETAILS BECOME SKETCHY BY MID
WEEK AS THE NUMERICAL MODELS ARE NOT IN AGREEMENT ON THE LOCATION
AND MAGNITUDE OF SMALL BUT IMPORTANT FEATURES.

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

LUDWIG SEP 08