Small Craft Advisory 1039, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
300 PM AKST WED DEC 23 2009

.MODEL DISCUSSION...MODELS ARE IN GOOD AGREEMENT FOR THE MOST PART.
ONLY SMALL CHANGE IS THE SHORT TERM IS THE NAM IS NOW BRINGING THE
DISSIPATING LOW ALONG THE EASTERN KENAI PENINSULA INTO NORTHERN COOK
INLET WHERE IT DISSIPATES OVERNIGHT INSTEAD INTO THE SOUTHWEST PRINCE
WILLIAM SOUND. THIS IS NOW THE AGREED UPON SOLUTION WITH ALL MODELS.
THE NAM DOES ENHANCE A SHORT WAVE IN THE GULF OF ALASKA FRIDAY INTO
SATURDAY MORE THAN OTHER MODELS DO. THIS WILL BE WORTH WATCHING TO
SEE IT THE NAM CHANGES OR IF THE OTHER MODELS START STRENGTHENING
THIS WAVE AS WELL.

.ANALYSIS AND UPPER LEVELS...VERY LITTLE CHANGE IN THE UPPER LEVEL
PATTERN WITH THE JET STREAM REMAINING ZONAL AND WELL SOUTH OF THE
FORECAST AREA. THE LOW OVER THE KENAI PENINSULA IS RAPIDLY
DISSIPATING BUT STILL HAS ENOUGH WARM AIR TO CAUSE RAIN AND FREEZING
RAIN I SOUTH CENTRAL ALASKA.
THE LARGE 960 MB LOW WELL SOUTH OF THE ALASKA PENINSULA HAD AN
OCCLUDED FRONT ALONG IT THAT IS APPROACHING THE ALASKA PENINSULA AND
THEN WILL OVER THE ALEUTIANS. THIS LOW IS GEOGRAPHICALLY VERY LARGE
AND WILL BECOME A DOMINANT WEATHER FEATURE OVER MUCH OF THE AREA
DESPITE THE FACT THE CENTER IS SO FAR SOUTH.

.SHORT TERM FORECAST...A WINTERY MIX IN THE COOK INLET REGION WITH
RAIN SNOW SLEET AND FREEZING RAIN. THE FREEZING RAIN SEEMS CONFINED
TO THE ANCHORAGE AREA THIS AFTERNOON AND WILL COOL OFF INTO SNOW
SHOWERS BY LATE THIS EVENING. EASTERN PRINCE WILLIAM SOUND WILL SEE
RAIN TURN MOSTLY TO SNOW AGAIN BY THE EVENING. THOMPSON PASS MAY NEED
A BLOWING SNOW ADVISORY FOR THE WINDS ASSOCIATED WITH THE SNOWFALL
THERE.

.LONG TERM FORECAST...LONG RANGE MODELS CONTINUE TO SHOW OVERALL
LITTLE CHANGE IN THE SYNOPTIC PATTERN THROUGH THE MIDDLE OF NEXT
WEEK. IT LOOKS LIKE THE MOST ACTIVE WEATHER WILL CONTINUE TO BE IN
THE VICINITY OF THE EASTERN ALEUTIANS AND FAR WESTERN GULF. INLAND
AREAS OF MAINLAND ALASKA LOOK TO STAY MOSTLY DRY WITH SLIGHTLY ABOVE
NORMAL TEMPERATURES THROUGH THE START OF NEXT WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 120 130 132 138 150 155 160 165 170 171.
FIRE WEATHER...NONE.

DEC 09