Small Craft Advisory 234, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 PM AKST MON FEB 28 2011

.ANALYSIS AND UPPER LEVELS...THE OMEGA BLOCK PATTERN REMAINS TODAY
WITH A STRONG UPPER LEVEL RIDGE OVER THE EASTERN BERING SEA AND
WESTERN ALASKA. THE 250 MB JET STREAM THAT HAS BEEN RIDING DUE NORTH
TO SOUTH AROUND THE EASTERN EDGE OF THE RIDGE IS WEAKENING AND MOVING
SLOWLY EASTWARD AND WILL CEASE TO BE A SIGNIFICANT FEATURE BY
TOMORROW. THE MAIN JET STREAM CONTINUES TO STAY WELL SOUTH OF THE
AREA NEAR 30N.
THE SURFACE HIGH DOMINATES THE INTERIOR OF THE STATE AND STRETCHES
WESTWARD INTO THE NORTHERN BERING SEA AND EASTWARD WELL INTO CANADA.
THE LOW TRACK REMAINS SOUTHWEST OF THE ALEUTIAN ISLANDS WITH A
FRONTAL BOUNDARY BETWEEN THE HIGH AND THE LOWS OVER THE CENTRAL TO
WESTERN BERING SEA AND ALEUTIAN ISLANDS.

.MODEL DISCUSSION...MODELS ARE STILL DOING A GOOD JOB HANDLING THE
CURRENT PATTERN. THE ONLY EXCEPTION IS WITH THE INDIVIDUAL LOWS ALONG
THE FRONTAL BOUNDARY JUST SOUTH TO SOUTHWEST OF THE ALEUTIANS. THE
MODELS EACH HAVE A DIFFERENT IDEA AS TO WHERE THE INDIVIDUAL LOWS
WILL DEVELOP BUT THEY ALL HAVE THE BOUNDARY ITSELF IN THE SAME PLACE
AND THEREFORE THE IMPACT ON THE FORECAST WILL BE MINIMAL.

.SHORT TERM FORECAST...THE HIGH WIND WARNINGS IN THE VALDEZ AREA AND
COPPER RIVER DELTA HAVE EXPIRED THIS AFTERNOON AS THE WINDS HAVE COME
DOWN ENOUGH TO REMAIN UNDER WARNING CRITERIA. THE WEAKENING OF THE
JET STREAM HAS BEEN A BIG FACTOR IN THIS AS WELL AS THE SOUTHWARD
MOVEMENT OF A LOW NEAR THE QUEEN CHARLOTTE ISLANDS. THE PRESSURE
GRADIENT WILL REMAIN SOMEWHAT TIGHT FOR A FEW MORE DAYS SO WINDS WILL
NOT COME DOWN ALL THE WAY FOR AWHILE IN THESE AREA.
SOUTH CENTRAL ALASKA WILL REMAIN CLEAR WITH NORTHERLY WINDS THE NEXT
DAY OR TWO.
SOUTHWEST ALASKA WILL REMAIN MOSTLY CLEAR THE NEXT FEW DAYS EXCEPT
FOR SOME HIGH CLOUDS THAT WILL SNEAK OVER THE RIDGE INTO THE AREA.
THE CENTRAL AND WESTERN ALEUTIAN ISLANDS WILL CONTINUE TO SEE WARM
SOUTHEAST FLOW WITH PERIODS OF RAIN OVER THE AREA.

.LONG TERM FORECAST...THE WEATHER PATTERN WE ARE IN WILL CHANGE VERY
LITTLE THROUGH THE WEEK. BY NEXT WEEKEND THE UPPER RIDGE CENTER WILL
HAVE MOVED INTO THE ARCTIC OCEAN OPENING UP THE GULF OF ALASKA TO A
WEAK UPPER LEVEL TROUGH. THIS WILL NOT HAVE A LOT OF IMPACT ON THE
WEATHER EXCEPT IT MAY BRING A FEW SNOW SHOWERS TO THE GULF OF ALASKA
COAST NEXT WEEKEND.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 172 175 176.
         HEAVY FREEZING SPRAY 120 121 125 129 130 140.
FIRE WEATHER...NONE.

EZ FEB 11