Heavy Freezing Spray Warning 2, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM AST WED JAN 2 2008

.MODEL DISCUSSION...MODELS ARE DOING FAIRLY WELL WITH THE UPCOMING
CALMER WEATHER PATTERN. ONLY REAL DISCREPANCIES LIE WITH THE MULTIPLE
WEAK SURFACE LOWS THAT WILL BE TRAVERSING OVER THE BERING OVER THE
NEXT COUPLE DAYS...AS WELL WITH THE WEAK LOWS OVER THE GULF THAT WILL
BE PRODUCED BY COLD AIR ADVECTION FROM THE NORTHWEST. THESE WEAK LOWS
WILL NOT HAVE ANY DRASTIC EFFECT ON THE FORECAST...THEREFORE WAS
CONFIDENT TO ONLY BLEND IN SOME OF THE NEW GFS MODEL SOLUTION INTO
THE PREVIOUS FORECAST PACKAGE.

.ANALYSIS AND UPPER LEVELS...AN UPPER LEVEL TROUGH WITH TWO EMBEDDED
LOWS RESIDES OVER THE MAINLAND AND GULF THIS MORNING. A ZONAL PATTERN
EXISTS OVER THE WESTERN HALF OF THE DOMAIN DUE TO A 180 KNOT JET
STREAM WELL SOUTH OF THE ALEUTIANS KEEPING A WEAK LOW OVER THE
WESTERN BERING AND A WEAK RIDGE OVER THE EASTERN BERING. THIS PATTERN
OVER THE WEST LOOKS TO HOLD THROUGH THE END OF THE WEEK WITH A DEEPER
TROUGH BUILDING OVER THE MAINLAND AND GULF.

AT THE SURFACE...A WEAKENING LOW IN THE GULF CONTINUES TO CARRY RAIN
AND SNOW SHOWERS ALONG THE COASTAL AREAS. A RIDGE OVER WESTERN ALASKA
HAS SKIES MOSTLY CLEAR AND WINDS MOSTLY LIGHT. A WEATHER FRONT
EXTENDING FROM A LOW OVER THE FAR WESTERN BERING IS STRETCHING ALONG
THE NORTHERN BERING DOWN OVER THE PRIBILOFS AND EASTERN ALEUTIANS.

.SHORT TERM FORECAST...
SOUTH AND EAST OF THE ALASKA RANGE...PRECIPITATION IN THE GULF WILL
DIMINISH AS THE RIDGE FROM THE WEST PUSHES THE WEAKENING GULF LOW
EAST TOWARD YAKUTAT BAY THROUGH THURSDAY. THE CYCLONIC FLOW AROUND
THE UPPER LOW OVER THE MAINLAND WILL PULL COLDER AIR SOUTH AND EAST
OVER THE ALASKA RANGE AND KEEP GENERAL LOWER PRESSURE IN THE GULF.

WESTERN ALASKA...GENERAL RIDGING WILL KEEP SKIES MAINLY CLEAR AND ANY
SIGNIFICANT PRECIPITATION FROM FALLING. HOWEVER AREAS OF MOISTURE
ALONG WITH THE COLDER AIR MASS WILL RIDE DOWN ON THE BACK SIDE OF THE
UPPER LOW TO BRING INTERMITTENT CLOUD COVER THROUGH THE END OF THE
WEEK.

ALEUTIANS/BERING...THE WEAKENING FRONT SHOULD DISSIPATE BY TOMORROW
AFTERNOON BRINGING AREAS OF SNOW TO THE PRIBILOFS...THE ALASKA
PENINSULA AND EASTERN ALEUTIANS. MANY OTHER WEAK SURFACE LOWS UNDER
THE UPPER LEVEL FEATURE WILL PRODUCE SNOW SHOWERS ALONG THE REST OF
THE CHAIN THROUGH THE WEEK.

.LONG TERM FORECAST...CYCLONIC FLOW OVER THE MAINLAND AND GENERAL LOW
PRESSURE IN THE GULF WILL BRING COLDER THAN NORMAL TEMPERATURES...
WITH THE BIGGEST ANOMALY OVER THE WESTERN MAINLAND. RIDGING WILL
REMAIN OVER THE ALEUTIANS THROUGH THIS WEEK WITH TWO NORTH PACIFIC
SYSTEMS PROGGED TO ENTER THE WESTERN ALEUTIANS EARLY NEXT WEEK.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALE 172 175 176 185
      ...HEAVY FREEZING SPRAY 150 160 180 185
FIRE WEATHER...NONE

LR JAN 08