Small Craft Advisory 816, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AKDT THU OCT 23 2008

.ANALYSIS AND UPPER LEVELS...
A 974 MB LOW IN THE NORTHERN GULF OF ALASKA JUST SOUTHWEST OF
MIDDLETON ISLAND IS THE MAIN FEATURE OF INTEREST THIS MORNING. THE
LOW MOVES ONSHORE NEAR CORDOVA THIS EVENING. SEVERAL WEAK SHORTWAVES
AND WEAK SURFACE LOWS IN COLD NORTHWEST FLOW ARE PRESENT OUT WEST.
ONE WEAK LOW IS OVER NORTON SOUND THIS MORNING AND TWO OTHERS ARE
PRESENT BETWEEN SAINT MATTHEW AND THE WESTERN ALEUTIANS.

.MODEL DISCUSSION...
MODELS ARE HAVING A FEW ISSUES AND FORECAST GENERALLY REFLECTS THE
BEST COMPROMISE POSSIBLE UNTIL THE MODELS GET A BETTER HANDLE ON
THINGS. ONE POINT OF CONTENTION IS THE HANDLING OF SEVERAL COMPLEX
LOWS OUT IN THE BERING. ANOTHER ISSUE IS A WEAK LOW TRYING TO
UNDERCUT THE EASTERN BERING RIDGE AND MOVE IN THE FAR WESTERN GULF
LATE FRIDAY OR FRIDAY NIGHT.

.SHORT TERM FORECAST...
SOUTHCENTRAL...
974 MB LOW PRESSURE SYSTEM TO MOVE ONSHORE AROUND CORDOVA THIS
EVENING. SNOW EXTENDS NORTH FROM THE LOW INTO PRINCE WILLIAM SOUND
AND THE COPPER RIVER BASIN. A WINTER WEATHER ADVISORY FOR SNOW IS IN
EFFECT LATE TODAY THROUGH TOMORROW MORNING FOR THE COPPER RIVER
BASIN...AND A BLIZZARD WARNING IS IN EFFECT FOR THOMPSON PASS. AREAS
WEST OF A LINE FROM THE WESTERN KENAI TO ANCHORAGE TO TALKEETNA ARE
EXPECTED TO REMAIN DRY FROM THIS SYSTEM. A BIG ISSUE WILL BE THE
WINDS TO THE NORTH AND WEST OF THE LOW. QUITE A FEW AREAS IN THE
NORTHERN GULF COASTAL WATERS...ESPECIALLY NEAR CHANNELED
TERRAIN...WILL SEE STORM FORCE WINDS OR WIND GUSTS LATE TODAY
THROUGH FRIDAY MORNING. THE COLDEST AIR OF THE SEASON WILL BE
USHERED IN ON THESE NORTH TO WEST WINDS AND WITH HIGH PRESSURE
BUILDING IN FRIDAY AFTERNOON AND EVENING...SATURDAY MORNING COULD BE
VERY COLD.

SOUTHWEST MAINLAND...
COLD TEMPERATURES WILL BE THE MAIN STORY OVER THE SOUTHWEST MAINLAND
THROUGH THE WEEKEND. WEAK SHORTWAVES IN NORTHWESTERLY FLOW WILL
BRING SOME ISOLATED SNOW SHOWERS TO THE REGION.

BERING SEA/ALEUTIANS...
COOL WEST TO NORTHWEST UPPER LEVEL FLOW WILL PERSIST THROUGH
SATURDAY WITH SHOWER ACTIVITY...MAINLY FALLING AS SNOW. WINDS WILL
GENERALLY BE AT OR BELOW SMALL CRAFT LEVEL WITH THE EXCEPTION OF
GALE FORCE WINDS TODAY INTO THIS EVENING FROM THE EASTERN ALEUTIANS
EASTWARD ON THE BACK SIDE OF THE GULF LOW.

.LONG TERM FORECAST...
ANOTHER DECENT LOW PRESSURE SYSTEM IS EXPECTED TO MOVE NORTH INTO
THE GULF OF ALASKA SATURDAY NIGHT OR SUNDAY. WARMER UPPER LEVEL
WESTERLY FLOW IS EXPECTED TO TAKE OVER AT LEAST THE WEST/CENTRAL
BERING/ALEUTIANS SUNDAY AND MONDAY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...BLIZZARD WARNING 131 THOMPSON PASS.
MARINE...STORM WARNING 120 130 132 351 352
         GALE WARNING 121 125 129 138 140 141 150 155 160 165 170
            414.
FIRE WEATHER...NONE.

FOISY OCT 08