Small Craft Advisory 16, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
130 PM AKST SAT JAN 5 2013

.ANALYSIS AND UPPER LEVELS...
A BROAD LONGWAVE TROUGH WITH SEVERAL LOWS WITHIN IT CONTINUES TO
LINGER OVER THE BERING SEA...WITH SOUTHERLY FLOW ACROSS THE SOUTHERN
MAINLAND. THERE ARE SEVERAL SURFACE FEATURES THAT ARE UNDER THE BROAD
UPPER TROUGH. THERE IS A LOW NORTH OF THE PRIBILOF ISLANDS THAT IS
MOVING NORTHWARD TODAY. A SURFACE LOW IN THE NORTH PACIFIC HAS
QUICKLY DEVELOPED AND DEEPENED THIS MORNING AND WILL CONTINUE TO DO
SO AS IT MOVES TOWARD THE EASTERN ALEUTIAN ISLANDS AND ALASKA
PENINSULA. ANOTHER LOW NEAR KODIAK ISLAND IS MOVING EASTWARD. THIS
LOW ALONG WITH A TROUGH AHEAD OF IT ARE BRINGING FAIRLY WIDESPREAD
PRECIPITATION TO THE SOUTHWEST MAINLAND AND GULF COAST
AREAS...ESPECIALLY NOW THAT MOST AREAS OF BRISTOL BAY ARE NOT
EXPERIENCING ENOUGH DOWNSLOPING TO OVERCOME THE SNOW.

.MODEL DISCUSSION...
MODELS ARE IN DECENT AGREEMENT FOR THE FIRST 24 TO 36 HOURS...THEN
STRUGGLE ESPECIALLY WITH THE TRACK AND SPEED OF THE NORTH PACIFIC LOW
AS IT APPROACHES THE ALASKA PENINSULA SUNDAY NIGHT. MODEL TRENDS SEEM
TO BE KEEPING THE LOW SOUTH OF THE PENINSULA AND INTO THE GULF OF
ALASKA...ALTHOUGH THE GFS STILL WANTS TO BRING IT TO THE WESTERN SIDE
OF THE ALEUTIAN RANGE AND LET IT SIT THERE FOR AWHILE. THE SOLUTION
REMAINING SOUTH OF THE PENINSULA IS FAVORED...ALTHOUGH THERE IS LESS
CONFIDENCE IN THE DETAILS BEYOND THAT. THEREFORE...THE NAM IS BEING
USED FOR THE FIRST 24 TO 36 HOURS TO TAKE ADVANTAGE OF ITS
DETAILS...AND THE ECMWF IS THE PREFERRED MODEL BEYOND THAT FOR ITS
CONSISTENCY AND REASONABLE TRACK.

.SHORT TERM FORECAST...
MAINLAND...A SOMEWHAT BRIEF PERIOD OF PRECIPITATION ALONG THE WESTERN
SIDE OF THE CHUGACH AND KENAI MOUNTAINS CAN BE EXPECTED LATE THIS
AFTERNOON AND THIS EVENING AS THE TROUGH SWINGS NORTHWARD FROM THE
GULF. ALONG THE COAST...PRECIPITATION WILL REMAIN LIKELY...WITH MOST
AREAS SEEING IT IN THE FORM OF RAIN. WEST OF THE ALEUTIAN
RANGE...TEMPERATURES ARE COOL ENOUGH FOR SNOW. SNOW WILL MOVE OFF TO
THE EAST AS THE LOW NEAR KODIAK MOVES EASTWARD...LEAVING A SHORT
BREAK BEFORE THE NEXT LOW BRINGS PRECIPITATION TO THE SOUTHWEST
MAINLAND.

BERING SEA AND ALEUTIANS...MULTIPLE LOWS WILL AFFECT THE BERING SEA
AND ALEUTIANS OVER THE NEXT FEW DAYS. WITH THE LOW SOUTH OF THE
ALEUTIANS AND AK PENINSULA...MODELS ARE TRENDING SOUTH ENOUGH THAT
STRONG WINDS SHOULD NOT BE A PROBLEM ALONG THE ALASKA PENINSULA.
STRONGER WINDS ARE EXPECTED WITH THE FRONT COMING INTO THE WESTERN
ALEUTIANS THE BEGINNING OF THE WEEK...FOR NOW WE KEEP THEM AT GALE
FORCE BUT THEY MAY VERY WELL NEED TO BE INCREASED TO STORM FORCE IF
MODELS CONTINUE TO SHOW THE STRONGER WINDS.

.LONG TERM FORECAST...
THE BROAD LOW OVER THE BERING WILL MOVE EASTWARD WITH THE STRONG
FRONT THAT WILL MOVE THROUGH THE BERING SEA AND ALEUTIANS THIS WEEK.
SEVERAL LOWS WILL MOVE THROUGH BEHIND THIS FRONT...AND WILL KEEP MOST
OF THE PRECIPITATION ALONG THE COAST. NO BIG TEMPERATURE CHANGES ON
THE HORIZON...JUST TRENDING MORE TOWARD NORMAL JANUARY TEMPERATURES
OVERALL.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALE 132 150 155 175 176
FIRE WEATHER...NONE

SCHRECK