Small Craft Advisory 325, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM ADT THU APR 10 2008

.ANALYSIS AND UPPER LEVELS...
MAIN UPPER TROUGH CURRENTLY RESIDES OVER CENTRAL ALASKA. THE POTENT
SHORTWAVE THAT BROUGHT SIGNIFICANT SNOWFALL TOTALS TO SOUTHCENTRAL
ALASKA IS ROUNDING THE BASE OF THE MAIN TROUGH AND WILL PUSH
NORTHEASTWARD TOWARDS THE YUKON TERRITORY BY FRIDAY MORNING. THIS
SHORTWAVES WEAK SURFACE REFLECTION IS OVER THE COPPER RIVER BASIN
THIS MORNING AND BRINGING SNOWFALL FROM THE SUSITNA VALLEY EAST TO
THE COPPER RIVER BASIN AND SOUTH TOWARDS THE NORTHERN GULF OF ALASKA
COAST. PRECIPITATION IN MOST AREAS WILL BEGIN TO WIND DOWN TODAY AND
TONIGHT AS THE SYSTEM MOVES NORTHEAST. OUT WEST...A RIDGE OF HIGH
PRESSURE OVER THE WESTERN BERING SEA WILL BEGIN TO PUSH EASTWARD AND
GENERALLY DRY CONDITIONS CAN BE EXPECTED FOR MOST OF THE MAINLAND
THROUGH THE WEEKEND. BEHIND THE RIDGE...A LOW PRESSURE SYSTEM WILL
BEGIN IMPACTING THE ALEUTIANS FRIDAY.

.MODEL DISCUSSION...
MODELS ARE GENERALLY IN GOOD AGREEMENT ON SYNOPTIC FEATURES. THERE
ARE SOME ISSUES WITH A LOW MOVING TOWARDS THE SOUTHEAST PANHANDLE
FRIDAY NIGHT...BUT WILL HAVE LITTLE IMPACT ON THE SOUTHCENTRAL ALASKA
FORECAST. THE NAM REMAINS TO BE THE MODEL OF CHOICE IN THE SHORT TERM
FOR ITS HANDLING OF MESOSCALE DETAILS IN THE SUSITNA VALLEY AND
COPPER RIVER BASIN...WITH A TRANSITION TOWARDS THE NEW GFS MODEL RUN
IN THE MEDIUM RANGE.

.SHORT TERM FORECAST...
SOUTH AND EAST OF THE ALASKA RANGE...
THE WEAK SOUTHCENTRAL SURFACE FEATURE WILL REMAIN TO BE THE FOCUS OF
ATTENTION FOR THE NEXT DAY OR TWO. SNOW IS WINDING DOWN IN THE
SUSITNA VALLEY THIS MORNING...AND THE SNOW ADVISORY HAS BEEN ALLOWED
TO EXPIRE. THE EASTERN PRINCE WILLIAM SOUND AREA AND COPPER RIVER
BASIN WILL SEE SNOW SHOWERS THROUGH TONIGHT WHEN THE LOW MOVES
NORTHEAST. WEATHER WILL BE RELATIVELY QUIET FRIDAY THROUGH THE
WEEKEND AS A RIDGE OF HIGH PRESSURE BEGINS BUILDING IN FROM THE WEST.
TEMPERATURES SHOULD REMAIN AT OR SLIGHTLY BELOW AVERAGE IN THIS
REGIME.

SOUTHWEST MAINLAND AND ALEUTIANS...
RELATIVELY QUIET PATTERN TODAY AND TONIGHT AS HIGH PRESSURE MOVES
EAST FROM THE WESTERN BERING SEA. TONIGHT WILL BE ANOTHER NIGHT OF
COLD TEMPERATURES AS FAIRLY CLEAR CONDITIONS WILL MAXIMIZE
RADIATIONAL COOLING. THE RIDGE WILL BE FORCED EASTWARD AS A LARGE LOW
PRESSURE SYSTEM BEGINS IMPACTING THE WESTERN ALEUTIANS LATE FRIDAY
AND THE SOUTHWEST MAINLAND BY SUNDAY MORNING. THIS SYSTEM APPEARS
FAIRLY WARM...SO PRECIPITATION WILL COME LARGELY IN THE FORM OF RAIN.

.LONG TERM FORECAST...
THE CURRENT HIGH AMPLITUDE WAVES WILL GIVE WAY TO MORE PROGRESSIVE
STORMS BY EARLY NEXT WEEK. EXPECT SEASONAL TEMPERATURES WITH ON-AGAIN
OFF-AGAIN PRECIPITATION AFTER THIS WEEKEND.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 130.
         HEAVY FREEZING SPRAY 130.
FIRE WEATHER...NONE.

DANG APR 08