Gale Warning 26, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AKST SAT JAN 30 2010

.ANALYSIS AND UPPER LEVELS...
A STRONG UPPER LEVEL LOW IS SITUATED OVER THE WESTERN BERING THIS
MORNING AND IS EXPECTED TO CONTINUE MOVING WESTWARD THROUGH THE DAY.
OVER THE GULF OF ALASKA A VERTICALLY STACKED LOW IS WEAKENING THIS
MORNING AND WILL GRADUALLY DISSIPATE.  TO THE EAST AN UPPER LEVEL
RIDE IS BUILDING OVER WESTERN CANADA. THIS FEATURE IS EXPECTED TO
STRENGTHEN OVER THE NEXT 24 HOURS WHICH WILL AID IN THE DISSIPATION
OF THE GULF OF ALASKA LOW.  THE MAIN JET STREAM IS STILL SOUTH OF THE
AREA OF RESPONSIBILITY ALTHOUGH THAT WILL CHANGE AS THE UPPER LEVEL
RIDGE BUILDS IN AND AN OMEGA BLOCK SETS UP OVER THE STATE.

.MODEL DISCUSSION...
IN THE SHORT TERM MODELS ARE IN FAIRLY GOOD AGREEMENT. THE NAM IS
SLIGHTLY SLOWER ON MOVING THE LOW IN THE GULF FURTHER SOUTH ON SUNDAY
AFTERNOON WHICH MADE THE GFS THE MODEL OF PREFERENCE FOR THE SHORT
TERM. IN THE WEST...DIFFERENCE BETWEEN THE MODEL RUNS BEGIN TO APPEAR
BY ABOUT 78 TO 84 HOURS...AROUND THE TUESDAY EVENING TIMEFRAME.  GFS
AND NAM HAVE THE LOW PRESSURE SYSTEM IN THE CENTRAL ALEUTIANS FURTHER
WEST THAN THE ECMWF...HOWEVER GFS IN PARTICULAR DOES NOT SEEM TO
HANDLE THE DISSOLUTION OF THE LOW ON TUESDAY MORNING VERY WELL.
THEREFORE THE ECMWF WAS THE MODEL OF CHOICE AGAIN IN THE LONGTERM
TODAY...BLENDED WITH HPC GUIDANCE.

.SHORT TERM FORECAST...
EAST OF THE ALASKA RANGE...FOG AND LOW STRATUS ARE DOMINANT IN MANY
LOCATIONS THIS MORNING...BUT THE WEATHER IS EXPECTED TO IMPROVE
THROUGH THE DAY AS THE RIDGE BRINGS IN SUNNY SKIES.  EXPECT FOG TO
CONTINUE TO BE A THREAT TONIGHT AS WELL...ALTHOUGH A WEAK EASTERLY
WAVE MAY BRING SOME SHOWERS TO THE NORTH GULF COAST FOR TONIGHT AND
MONDAY.  THESE SHOWERS WILL BE MIXED PRECIPITATION OR EVEN ALL RAIN
FURTHER SOUTH WITH WARMER TEMPERATURES REMAINING ALOFT.  BY TUESDAY
THE SHORTWAVE TROUGH WILL MOVE SOUTH AND SKIES WILL CLEAR AGAIN.

WEST OF THE ALASKA RANGE...ISOLATED SHOWERS LINGER THIS MORNING SOUTH
OF BRISTOL BAY BUT ARE EXPECTED TO GRADUALLY DIMINISH AS THIS REGION
ALSO FALLS UNDER THE INFLUENCE OF THE UPPER LEVEL RIDGE.  AREAS OF
FOG AND LOW STRATUS PERSIST ALONG THE WEST COAST BUT MAY BE LESS OF A
FACTOR TOMORROW NIGHT AS THE FLOW BECOMES MORE OFFSHORE. BY TUESDAY A
FRONTAL BAND IS EXPECTED TO MOVE IN FROM THE SOUTH...ALTHOUGH WINDS
WILL NOT BE STRONG WITH THIS BAND TEMPS ALOFT WILL BE FAIRLY WARM AND
THE PRECIP WILL BE MIXED THROUGH BRISTOL BAY BUT WILL REMAIN ALL SNOW
IN THE KUSKOKWIM DELTA.

IN THE BERING/ALEUTIANS...EARLIER MODEL RUNS INDICATED THAT THE LOW
PRESSURE SYSTEMS AND THEIR ASSOCIATED FRONTS WOULD REMAIN WELL SOUTH
OF THE CHAIN BUT THIS SEEMS TO NO LONGER BE THE CASE.  THE LOW
PRESSURE SYSTEM ALREADY EVIDENT ON SATELLITE WILL REMAIN JUST SOUTH
OF THE ALEUTIANS BUT ITS ASSOCIATED FRONT IS EXPECTED TO TRAVERSE THE
BERING SUNDAY AND INTO MONDAY.  AGAIN WINDS WILL REMAIN FAIRLY LIGHT
WITH THIS FRONT...BUT TEMPS ARE WARM AND RAIN CAN BE EXPECTED FOR THE
ALEUTIANS WITH MIXED PRECIP MAKING ITS WAY INTO THE PRIBILOFS BY
SUNDAY AFTERNOON.

.LONG TERM FORECAST...
HIGH PRESSURE LOOKS TO REMAIN THE DOMINANT FEATURE FOR THE MAINLAND
THROUGH THE END OF NEXT WEEK...WITH THE POSSIBILITY OF MORE ISOLATED
SHOWERS ALONG THE GULF COAST AS VERY WEAK SHORTWAVES PROGRESS
THROUGH.  IN THE ALEUTIANS...RAINY CONDITIONS WILL CONTINUE BUT
STRONG WINDS ARE NOT EXPECTED AS THE LOW WEAKENS AND MOVES SOUTH
FAIRLY RAPIDLY BY MIDWEEK.  GIVEN THE RECENT CHANGES IN THE MODEL
FORECAST HOWEVER...THE CONFIDENCE IN THE MIDWEEK FORECAST IS ONLY
FAIR.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...HEAVY FREEZING SPRAY 185
FIRE WEATHER...NONE

LEWF JAN 10