Small Craft Advisory 6, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 PM AST MON JAN 1 2007

.DISCUSSION...NAM/GFS MODEL MSLP/300MB HT INITIALIZATIONS REASONABLE.
NAM DOES A LITTLE BETTER IN MSLP WITH DUAL CENTERS IN THE GULF. GFS
QPF FIELD A LITTLE BETTER WITH WESTWARD PUCH OF MOISTURE INTO
SOUTHCENTRAL TODAY. FORECAST TRENDS IN GULF IN CLOSE AGREEMENT AND
REASONABLE. OUTWEST...WOULD LEAN TOWARD GFS SOLUTION WITH NEXT MAJOR
LOW TO IMPACT THE ALEUTIAN ISLANDS.

.UPPER AIR...LONG WAVE OVER THE WESTERN MAINLAND DIGS SOUTHEAST WITH
COLD ADVECTION AND TAKES ON NEG TILT OVER SOUTHWEST AK AND GULF TUE
NIGHT/WED. THIS WILL BRING SOUTHCENTRAL AK UNDER SE FLOW AND INCREASE
UPWARD VERTICAL MOTION OVER THE AREA. BERING SEA RIDGE INCREASES SOME
IN AMPLITUDE AS LOW CENTER MOVES TO NEAR THE KAMCHATKA PEN WED.

.SURFACE...

.EAST...GULF COMPLEX WEAKENS TONIGHT WITH ONE CENTER MOVING TO THE NE
GULF AND WEAKENING. SECONDARY CENTER MOVES TO SOUTH THE AK PEN
TONIGHT AND WEAKENS. WESTERN EXTENT SNOW TODAY AND TONIGHT APPEARS TO
BE THE ANCHORAGE BOWL...EASTERN KENAI PEN...AND MAT VALLEY. GFS
APPEARS TO HAVE GOOD HANDLE ON THIS AND ACTUALLY SHOWS MOISTURE
LIFTING FROM THE SOUTH THROUGH TONIGHT. CURRENT SAT AND RADAR SUPPORT
THIS SENARIO. MOISTURE INTRUSION INTO COPPER RIVER BASIN THROUGH THIS
EVENING LOOKS REASONABLE TO HOLD SNOW ADVISORY IN AREA. NEXT CENTER
DEVELOPING OVER THE NE PACIFIC IS FORECAST TO MOVE INTO WESTERN
PRINCE WILLIAM SOUND EARLY WED MORNING. AT SAME TIME UPPER TROUGH
TAKES ON NEG TILT AND 850 MB SHOWS NICE COLD ADVECTION. IF THIS ALL
COMES INTO PLAY COULD SEE SIGNIFICANT SNOW EVENT OF THE ANCHORAGE
BOWL AND MAT VALLEY WED. CONCERN IS THAT MODELS DIFFER SOMEWHAT ON
TIMING OF CENTER...GFS BEING THE FASTER OF THE TWO. FOR NOW WILL
CONTINUE SNOW IN FORECAST AND TAKE A LOOK AT NEXT MODEL RUN BEFORE
ISSUING WSW PRODUCT.

.WEST...GENERALLY DRY CONDITIONS LIKELY TO CONTINUE OVER THE SW
MAINLAND THROUGH TONIGHT. MAY SEE A LITTLE MORE IN THE WAY OF CLOUDS
AND ISOLATED SNOW SHOWER POTENTIAL(FAIRLY SLIGHT) AS UPPER CENTER
MOVES INTO REGION TUE/WED. BROAD N/NE FLOW OFF ICE PAC WILL KEEP
OPEN/CLOSED CELL CU OVER MUCH OF THE BERING SEA THROUGH TONIGHT. NLY
FLOW WEAKENS OVER THE CENTRAL BERING SEA TONIGHT/TUE WITH EASTWARD
PUSH OF RIDGE. WINDS BECOMING LIGHT AND AS FAR EAST AS THE PRIBILOFS
TUE NIGHT/WED MORNING...HOWEVER GUSTY NORTHWEST WINDS WILL CONTINUE
OVER THE AK PEN. ALL THIS SAID...EXPECT SNOW SHOWER ACTIVELY WITH
SOME BLOWING SNOW OVER THE PRIBILOFS ALEUTAINS WILL DIMINISH WITH
SHIFTING AND WEAKENING OF NLY FLOW. SNOW SHOWERS LIKELY TO HOLD OVER
THE AK PEN INTO WED. NEXT CENTER TO IMPACT THE ALEUTIANS BRINGS
WARMING TEMPS AND E-SE GALES/STORMS WED.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 129, 130, 132, 150
         HEAVY FREEZING SPRAY 130, 138, 140, 141, 150, 165, 179, 185
FIRE WEATHER...NONE.

RMC JAN 07