Small Craft Advisory 362, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKDT WED APR 24 2013

.MODEL DISCUSSION...
THE NUMERICAL GUIDANCE IS IN GOOD AGREEMENT TODAY. THIS IS NOT
SURPRISING AS A "REX BLOCK" (AN UPPER LEVEL HIGH NORTH OF A LOW) IS
OVER THE BERING SEA AND NORTH PACIFIC AND THIS IS A STABLE AND
PREDICTABLE PATTERN. THEREFORE CONFIDENCE IN THE FORECAST IS HIGH.

.ANALYSIS AND UPPER LEVELS...
AN UPPER LEVEL HIGH OVER THE BERING SEA IS FORMING A REX BLOCK WITH
A LOW SOUTH OF THE ALEUTIANS. NORTHERLY FLOW AROUND THIS BLOCK IS
SURGING SOUTHWARD TOWARDS SOUTHERN ALASKA. THERE IS A TROUGH OVER
SOUTH CENTRAL ALASKA ATTACHED TO A LARGE UPPER LOW OVER NORTHWEST
CANADA.

.SHORT TERM FORECAST...
FOR SOUTH CENTRAL AND SOUTHWEST ALASKA...THE TROUGH OVER SOUTHERN
ALASKA WILL SHARPEN TONIGHT AND PUSH SOUTH INTO THE GULF THURSDAY.
NORTHERLY FLOW ALOFT WILL BECOME STRONG ON THURSDAY AS CROSS-POLAR
FLOW WORKS ITS WAY OVER THE AREA. THIS WILL BRING A SLUG OF DRY AIR
INTO SOUTHERN ALASKA THAT WILL PERSIST INTO FRIDAY. ON FRIDAY NIGHT
AND SATURDAY A SHORT WAVE TROUGH WILL MOVE INTO SOUTHERN ALASKA FROM
THE NORTH...BUT CURRENTLY IT LOOKS LIKE CHANCES OF PRECIPITATION
WILL BE LOW AND MAINLY OVER SOUTHWEST ALASKA AND THE HIGHER
ELEVATIONS OF SOUTH CENTRAL ALASKA.

FOR THE BERING SEA AND ALEUTIANS...THE REX BLOCK HIGH WILL REMAIN
OVER THE BERING SEA THROUGH AT LEAST SATURDAY (AND LIKELY INTO NEXT
WEEK) WHILE DRIFTING VERY SLOWLY SOUTH AND WEST.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING 127.
FIRE WEATHER...NONE.

LUDWIG APR 13