Small Craft Advisory 984, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AST FRI NOV 25 2005

.DISCUSSION...

.MODEL ANALYSIS...AFTER A FEW DAYS OF VERY POOR RUN-TO-RUN
CONSISTENCY THE MODEL SOLUTIONS HAVE COME BACK INTO SYNC. 00Z
SOLUTIONS FOR THE NEXT FEW DAYS ARE VERY SIMILAR TO YESTERDAYS.
NAM/GFS/UKMET ALL INITIALIZED WELL. UKMET IS A BIT OF AN OUTLIER
IN HANDLING FRONTAL LOW THAT DEVELOPS AND MOVES UP TO THE ALEUTIANS
SATURDAY NIGHT. GFS HAS BEEN VERY CONSISTENT WITH HANDLING OF THIS
OVER THE LAST THREE RUNS. THEREFORE...THIS MORNINGS FORECASTS ARE
BASED ON GFS MODEL.

.SOUTHCENTRAL ALASKA...THE LOW THAT MOVED ACROSS PRINCE WILLIAM
SOUND AND THE COPPER RIVER BASIN YESTERDAY IS NOW WEAKENING OVER
THE YUKON. THE UPPER LOW CENTER THAT HAS BEEN SITTING OVER
SOUTHWEST ALASKA IS CURRENTLY MOVING INTO THE NORTHERN GULF.
COLD AIR ADVECTION BEHIND THIS UPPER CENTER IS BEGINNING TO
PRODUCE STRONG WINDS THROUGH THE GAPS IN THE ALASKA PENINSULA
WITH 40 KT PLUS GUSTS AT AUGUSTINE ISLAND. COLD ADVECTION IS
ALSO KEEPING THE SNOW GOING FROM ANCHORAGE TO HOMER AND GENERATING
WIDESPREAD SHOWERS ACROSS THE GULF...SOME OF THESE WITH MODERATE
TO HEAVY SNOW. MOST OF THE SHOWERS ARE CURRENTLY ROTATING NORTHWARD
INTO SOUTHEAST PRINCE WILLIAM SOUND. AS THE UPPER LOW MOVES TO
THE NORTH GULF TONIGHT FLOW WILL BECOME NORTHERLY INLAND AND ANY
REMAINING SNOW SHOWERS WILL CUT OFF. SNOW SHOWERS WILL CONTINUE
ALONG COASTAL AREAS UNTIL THE UPPER LOW DROPS SOUTHWARD ON SATURDAY.
EXPECT LIGHT ACCUMULATIONS IN SNOW SHOWERS WITH THE EXCEPTION OF
SOUTHEAST PRINCE WILLIAM SOUND WHICH WILL CONTINUE TO GET THE
BRUNT OF THE SNOW SHOWERS MOVING IN FROM THE GULF. EXPECT 5 TO 10
INCHES WILL FALL BY SATURDAY MORNING. AS HEAD THROUGH THE WEEKEND
EXPECT DECREASING CLOUDS ACROSS SOUTHCENTRAL WITH OFFSHORE FLOW
AND TEMPS A BIT BELOW NORMALS.

.SOUTHWEST ALASKA/AKPENN...SNOW SHOWERS AND GUSTY WINDS WILL
CONTINUE ON THE BACK SIDE OF UPPER TROUGH TODAY AND TONIGHT.
A RIDGE WILL THEN MOVE TO THE SOUTHWEST COAST THIS WEEKEND
RESULTING IN MOSTLY CLEAR SKIES AND COLD TEMPERATURES.

.BERING SEA/ALEUTIANS...WATER VAPOR IMAGERY SHOWS A LOW NEAR
50N 166E WITH A COLD FRONT EXTENDING ALL THE WAY DOWN TO 30N WITH
A COUPLE WEAK LOWS ALONG IT. DEEP MOISTURE IS BEING TRANSPORTED
NORTHWARD UP INTO THE WESTERN BERING. THE LOW IS RIDING NORTHWARD
UP THE WESTERN SIDE OF THE CENTRAL BERING RIDGE. THIS WILL PUSH THE
FRONT SLOWLY EASTWARD ACROSS THE ALEUTIANS AND CENTRAL BERING TODAY
AND SATURDAY. EXPECT STORM FORCE WINDS AND SOME MODERATE RAIN ALONG
THE FRONT. ONE OF THE FRONTAL LOWS WILL DEVELOP ON THE HEAD OF A
150 KT JET COMING OUT OF ASIA AND MOVE TO THE CENTRAL ALEUTIANS
SATURDAY NIGHT AND NORTHWARD ACROSS THE BERING. AS THIS LOWS COMES
UP THE RIDGE WILL BE PUSHED AGAINST SOME MORE AND THE COLD FRONT
WILL MAKE MORE PROGRESS EASTWARD ON SUNDAY INTO THE EASTERN BERING
AND ALASKA PENINSULA.

.EXTENDED FORECASTS...GFS INDICATES AN UPPER LEVEL RIDGE WILL
PERSIST SOUTH OF THE ALASKA PENINSULA AND GULF OF ALASKA NEXT WEEK.
THIS WILL KEEP MOST OF THE ACTION OUT WEST OVER THE BERING AND
ALEUTIANS WITH THE POSSIBILITY THAT SOMETHING MAY RIDE OVER THE
TOP OF THE RIDGE INTO THE MAINLAND.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORMS 172 175 176. GALES 150 155 160 165 185.
         HEAVY FREEZING SPRAY...130 138 140 141 160 180 185.

SEB NOV 05