Small Craft Advisory 147, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
300 PM AST FRI FEB 9 2007

.DISCUSSION...
IN THE UPPER LEVELS...THE RIDGE OVER THE GULF OF ALASKA WILL REMAIN
IN PLACE AND SLOWLY WEAKEN THROUGH THE WEEKEND. AN UPPER TROUGH OVER
THE INTERIOR WILL STRENGTHEN SATURDAY AND THEN WEAKEN AGAIN SUNDAY.
THE ONLY EFFECT THIS TROUGH MIGHT HAVE ON THE WEATHER IN SOUTH
CENTRAL ALASKA IS THAT IT MIGHT HELP INCREASE THE VERTICAL MOTION AND
BREAK UP THE LOWER LEVEL CLOUDS THAT HAVE STAGNATED OVER THE AREA.
IN THE WEST AN UPPER LEVEL LOW THE IS CURRENTLY CENTERED OVER
KAMCHATKA WILL MOVE OVER THE CENTRAL ALEUTIAN ISLANDS ON SUNDAY.

AT THE SURFACE...NOT A WHOLE LOT GOING ON IN THE EASTERN PART OF THE
FORECAST AREA. THE CENTER OF THE HIGH PRESSURE IS WELL INTO CANADA
WITH THE RIDGE EXTENDING THROUGH THE GULF OF ALASKA. THIS PATTERN
WILL REMAIN INTACT THROUGH SATURDAY NIGHT WHEN A WEAK TROUGH DEVELOPS
ALONG THE NORTH GULF COAST. THIS PATTERN WILL FAVOR THE CLOUDS
REMAINING IN SOUTH CENTRAL ALASKA UNTIL SOME VERTICAL MOTION CAN HELP
MIX OUT THE MOISTURE TRAPPED AT LOW LEVELS.
IN THE WEST A WEAK FRONT OVER THE EASTERN BERING SEA WILL DISSIPATE
OVERNIGHT. A LOW SOUTH OF THE ALEUTIAN ISLANDS WILL MOVE TO NEAR ATKA
SUNDAY AFTERNOON AND STRENGTHEN INTO THE MID 970S MB. GALES WILL
OCCUR AROUND THIS LOW AND POSSIBLY STORM FORCE WINDS AS IT MOVES INTO
THE CENTRAL ALEUTIANS BUT NO WIND WARNINGS WILL BE NECESSARY WITH IT.

MODELS FROM THE 12Z MODEL RUNS ARE IN GOOD AGREEMENT IN THE SHORT
TERM. IN THE LONGER TERM THERE ARE SOME DIFFERENCES BETWEEN THE GFS
AND ECMWF BUT ONE WILL NOT GO TOO FAR WRONG WITH THE GFS FOR THE
ENTIRE PERIOD.

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

FEB 07