Gale Warning 350, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
500 AM AKDT SAT APR 6 2013

.MODEL DISCUSSION...
THE GLOBAL MODELS ARE IN GOOD AGREEMENT WITH THE LOW PRESSURE SYSTEM
SOUTH OF THE ALEUTIANS WITH IT WEAKENING AND DISSIPATING THIS
AFTERNOON. THE MODELS ARE DOING BETTER WITH PLACEMENT OF NEW LOW
DEVELOPING FROM BARREN ISLANDS TO JUST WEST OF SEWARD. THE WEST DESK
USED THE GFS/EC FOR THE SHORT TERM AND TRANSITIONED TO WPC/EC/GEM
BLEND FOR THE EXTENDED. THE EAST DESK USED THE NAM FOR THE SHORT TERM
AND EC THROUGH THE EXTENDED. THE NAM BRINGS IN THE HEAVIER
PRECIPITATION THIS MORNING...COMPARED TO THE EC/WRF THIS AFTERNOON.

.ANALYSIS AND UPPER LEVELS...
THE SHORT WAVE TROF DROPPED DOWN FROM THE ALASKA RANGE THROUGH THE
MATANUSKA SUSTINA VALLEY INTO ANCHORAGE EARLY THIS MORNING KICKING
OFF SNOW SHOWERS. ALSO WITH A LOW DEVELOPING IN LOWER KENAI PENINSULA
AND WITH SYNOPTIC SUPPORT ALOFT WILL PRODUCE SNOW THROUGH THIS
WEEKEND. THE STEADIER SNOWFALL WILL START BY EARLY AFTERNOON INTO
REST OF THE WEEKEND. THE JET STREAM IS MERIDONAL OVER SOUTHCENTRAL
ALASKA...MATANUSKA SUSTINA VALLEY AND ANCHORAGE ARE POSITIONED IN THE
REAR ENTRANCE OF JET STREAM.

.SHORT TERM FORECAST...

SOUTHCENTRAL...
THE UPPER LEVEL LOW CONTINUES TO TRACK OVER SOUTHWESTERN ALASKA TODAY
WITH THE SHORT WAVE TROF OUT AHEAD THE LOW WILL CONTINUE TO PUSH
THROUGH THE SOUTHCENTRAL ALASKA TODAY. LOOK FOR A SURFACE LOW TO FORM
OVER SOUTHERN KENAI REGION LATER THIS MORNING. THE SNOW SHOWERS
THROUGH THE MATANUSKA SUSTINA VALLEY AND ANCHORAGE EXTENDING TO
SOUTHERN KENAI PENINSULA WILL BECOME STEADIER THIS AFTERNOON AND
CONTINUE THROUGH SUNDAY WITH THE MOISTURE FROM THE GULF BEING
ADVECTED IN WITH THE LOW.

SOUTHWEST...
THE NORTHERLY OFFSHORE FLOW WILL CONTINUE OVER SOUTHWEST COASTLINES
WITH WINDS TO REMAINING GUSTY WITH CONTINUED COLD AIR ADVECTION FROM
THE SHORT WAVE TROF THAT HAS PUSHED THROUGH THE ALASKA RANGE. THE
KUSKOKWIM DELTA WILL BE BORDERLINE FOR WIND CHILL ADVISORIES THROUGH
SUNDAY WITH THE COLD AIR ADVECTION TAPERING OFF ALONG WITH THE WINDS.

BERING SEA AND ALEUTIANS...
FOR THE MOST PART THE BERING SEA WILL CONTINUES WITH EASTERLY WINDS.
THE WESTERN ALEUTIANS WILL HAVE SHOWERY PRECIPITATION TODAY DUE TO A
WEAK SURFACE THAT HAS FORMED THIS MORNING. THIS LOW WILL TRACK SOUTH
OF WESTERN ALEUTIAN THIS AFTERNOON. THE CENTRAL BERING SEA HAS A
RIDGE OF HIGH PRESSURE BRINGING DRIER CONDITIONS. ONE AREA OF
POSSIBLE CONCERN IS WITH THE PRIBILOF ISLANDS WITH THE ICE EDGE SO
CLOSE AND THE COLD EASTERLY WINDS OVER THE WARMER WATER THAT COULD
BRING SNOW SHOWERS INTO THE PRIBILOF ISLANDS.

.LONG TERM FORECAST...
THE CENTRAL GULF WILL HAVE ANOTHER GULF LOW POSITIONED IN THE MIDDLE
OF THE GULF MONDAY AFTERNOON AND TRACKING INLAND NEAR YAKUTAT TUESDAY
EVENING. THE BERING SEA WILL HAVE HIGH PRESSURE SETTING UP THROUGH
EARLY NEXT WEEK WITH THE SOUTHWEST ALASKA COASTLINES GETTING
NORTHEASTERLY FLOW AND POSSIBLE WIND CHILL CONCERNS WITH MORE COLD
AIR ADVECTION.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...WINTER WEATHER ADVISORY FOR SNOW 101 111.
MARINE...GALE WARNINGS 170 172 175 176.
FIRE WEATHER...NONE.

PLD APR 13