Small Craft Advisory 116, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AST SAT FEB 4 2006

.DISCUSSION...
THE UPPER LEVEL LOW CONTINUES TO RETROGRADE TOWARD THE KAMCHATKA
PENINSULA.  THIS RETROGRESSION IS CAUSING THE LOW AT THE LOWER LEVELS
TO RETROGRADE SLIGHTLY AS WELL PULLING IT INTO THE BERING SEA THIS
MORNING.  300 MB CHART INDICATES A 165KT JET MOVING INTO THE BASE OF
THE SHORTWAVE ALONG THE WEST COAST.  THIS WILL STRENGTHEN THE LOW AS
IT MOVES NORTHWARD.  THIS IS A VERY DYNAMIC SYSTEM WITH PLENTY OF
TEMPERATURE ADVECTION ON BOTH THE WARM SIDE AND THE COLD SIDE.  850
MB CHART SHOWS A STRONG LOW LEVEL JET AHEAD OF THE WARM FRONT IN
PARTICULAR.  QUIKSCAT IMAGERY INDICATES THAT THESE WINDS ARE MIXING
DOWN TO THE SURFACE AND WARNING LEVEL WINDS ARE EXPECTED AHEAD OF THE
FRONT FOR THE COASTAL AREAS.

IN THE EAST...AS THE FRONT APPROACHES CONDITIONS WILL RAPIDLY
DETERIORATE FOR MOST OF THE ZONES.  WARNING LEVEL WINDS ARE EXPECTED
IN THE KODIAK ZONE TODAY.  AS THE FRONT APPROACHES THE SOUTHCENTRAL
REGION IT WILL WEAKEN...BUT WITH THE EFFECTS OF CHANNELING WINDS WILL
STILL REACH WARNING LEVEL IN THE TURNAGAIN ARM.  PRECIPITATION ALONG
THE KENAI PENINSULA AND TURNAGAIN ARM WILL START OUT AS SNOW BUT
EVENTUALLY BECOME MIXED WITH RAIN AS THE LOWER LAYERS WARM UP. THE
COMBINATION OF WINDS AND SNOW ALONG THE TURNAGAIN ARM WILL REDUCE
VISIBILITY DRASTICALLY ALONG THE TURNAGAIN ARM AND A WINTER STORM
WARNING IS IN EFFECT BEGINNING TONIGHT.  EAST OF THE KENAI PENINSULA
GALE WINDS CAN BE EXPECTED BUT PRECIPITATION SHOULD BE NEGLIGABLE.

OUT WEST...STRONG WINDS CONTINUE TO CHANNEL ALONG THE AK PEN AND WILL
CONTINUE UNTIL THE LOW MOVES NORTH OF THE ALEUTIANS.  DOWNSLOPING
WILL KEEP MOST PRECIP AWAY FROM THE WESTERN SIDE OF THE ALASKA RANGE
BUT DILLINGHAM AND AREAS WESTWARD...INCLUDING THE KUSKOKWIM
DELTA...COULD SEE A FAIR AMOUNT OF SNOW WITH THE WARM AIR
OVERRUNNING.  STRONG WINDS WILL REDUCE VISIBILITIES WITH BLOWING SNOW
AS WELL AND A WINTER STORM ADVISORY IS IN EFFECT FOR BRISTOL BAY WITH
A BLOWING SNOW ADVISORY FOR THE KUSKOKWIM DELTA.  IN THE PRIBILOFS
THE WINDS ARE NORTH TO NORTHEASTERLY ON THE OTHER SIDE OF THIS LOW
AND BLIZZARD CONDITIONS WILL CONTINUE THROUGHOUT THE DAY.  AS THE LOW
MOVES NORTHWARD THE CENTER SHOULD MOVE CLOSER TO THE PRIBILOFS AND
THE WINDS WILL ABATE A LITTLE...IMPROVING CONDITIONS BY TOMORROW
MORNING.

MODEL DISCUSSION...MODELS APPEAR TO AGREE ON CENTRAL PRESSURE VALUES
AND PLACEMENT UNTIL SUNDAY AT 00Z.  AT THAT POINT ETA DIVERGES FROM
THE OTHER THREE MODELS UNTIL MONDAY AT 00Z.  THIS IS VERY SIMILAR TO
YESTERDAYS PROBLEM.  ALSO NOTICED WAS THAT IN SPITE OF THE FACT THAT
ETA INITIALIZED WELL ON PRESSURE VALUES THE WIND FIELDS WERE TOO WEAK
ALONG THE AK PEN.  THE MODEL SEEMS TO HAVE CORRECTED FOR THIS ON THE
12Z RUN BUT BEARS WATCHING.

EXTENDED FORECAST...BY THE BEGINNING OF NEXT WEEK WARMER TEMPERATURES
WILL HAVE HIT THE MAINLAND.  GFS INDICATES THAT THE MAIN LOW WILL
REMAIN IN THE BERING SEA WITH SEVERAL LOWS FORMING TO THE SOUTH AND
MOVING INTO THE PANHANDLE.  TEMPERATURES WILL COOL SLIGHTLY BUT MOST
LIKELY BE ABOVE AVERAGE WITH THIS PATTERN.  BY THE MIDDLE OF NEXT
WEEK ANOTHER MAJOR LOW PRESSURE SYSTEM MOVES UP TOWARD THE ALEUTIANS.
MODELS INDICATE THAT THIS LOW WILL DEVELOP AND MOVE IN THE SAME
MANNER AS THE ONE CURRENTLY MOVING TOWARD THE BERING...SO A WARM WET
WINDY PATTERN LIES AHEAD.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...
MARINE...
FIRE WEATHER...NONE

LEW FEB 06