Heavy Snow in Alaska, January 7 to 8, 2008

SOUTHEAST ALASKA FORECAST DISCUSSION
1100 AM AST MON JAN 7 2008

.SYNOPSIS...
.SHORT RANGE...THE MORNING SATELLITE LOOP SHOWS A PERSISTING LOW
OVER NORTH CENTRAL GULF WITH ASSOCIATED FRONT MOVING ACROSS THE
PANHANDLE.  WATER VAPOR IMAGERY DEPICTS A CLEAR DEFORMATION ZONE
AT THE LEADING EDGE OF THE FRONTAL BOUNDARY NOSING TO YAKUTAT
AREA.  WITH MORE SOUTHERLY FLOW TODAY...THE CURRENT SNOW ADVISORY
FOR YAKUTAT LOOKS REASONABLE TO GO THROUGH THIS EVENING.  A MINOR
CONFLICT APPEARS AMONG THE MODELS LATE TUESDAY AFTERNOON BUT
STILL PREFER TO USE THE GFS OUTPUTS FOR THE SHORT RANGE FORECAST
TO KEEP THE CONSISTENCY.

THE INCOMING LOW...LOOKS LIKE ABOUT 973 MB...OVER THE SOUTH
EASTERN GULF WILL CONTINUE TO MOVE NORTH SLOWLY...MAINTAINING
VERY MUCH THE SAME INTENSITY THROUGH TUESDAY MORNING AS IT
REACHES WELL WEST OF THE QUEEN CHARLOTTES.  THE ASSOCIATED FRONT
WITH THE LOW WILL CONTINUE TO MOVE NORTH THROUGH THE END OF THE
SHORT TERM FORECAST PERIOD.  THIS WILL GENERATE ADVISORY LEVEL
WINDS ACROSS THE MUCH OF THE SOUTHERN ZONES THIS AFTERNOON
THROUGH TUESDAY AS WELL AS GALE FORCE WINDS FOR THE OFFSHORE
WATERS...ACROSS MOST OF OUTSIDE WATERS AND CLARENCE STRAIT. SMALL
CRAFT WINDS WILL CONTINUE FOR THE REST OF COASTAL WATERS. AHN

.LONG RANGE...A LOW OVER THE EASTERN GULF WILL WEAKEN AND
CONTINUE TO MOVE NORTHWEST TUESDAY NIGHT INTO WEDNESDAY SPREADING
MOISTURE NORTHWARD ACROSS THE PANHANDLE. AT THIS TIME EXPECT MOST
OF THE PRECIPITATION TO OCCUR ACROSS THE SOUTHERN PANHANDLE WITH
LIGHTER PRECIPITATION AMOUNTS FARTHER NORTH WITH THE UPPER LEVEL
WAVE WEAKENING AND CONTINUED SOUTHEASTLY FLOW. THE WAVE AS A
WHOLE DOES NOT APPEAR THAT IMPRESSIVE AT THE MOMENT WITH NO UPPER
LEVEL JET SUPPORT WHICH THE MODELS REFLECT IN THE LIGHTER
PRECIPITATION AMOUNTS. WINDS WITH THE FRONTAL BAND SHOULD
CONTINUE DIMINISH INTO EARLY WEDNESDAY. AS FAR AS PRECIPITATION
TYPE EXPECTING A RAIN/SNOW MIX OVER THE SOUTHERN PANHANDLE
TUESDAY NIGH INTO WEDNESDAY WITH SNOW ACROSS THE REST OF THE
PANHANDLE. AFTER THE FRONT MOVES ONSHORE BY WEDNESDAY AFTERNOON
THE ENTIRE PANHANDLE SHOULD EXPECT SCATTERED SNOW SHOWERS THROUGH
THURSDAY.

MODEL CONSENSUS IN GOOD AGREEMENT THROUGH FRIDAY AFTERNOON.
LEANED TOWARD THE 00Z ECMWF TUESDAY NIGHT THROUGH THURSDAY AS IT
HAS BEEN MORE CONSISTENT WITH PUSHING THE LOW INTO THE NORTHERN
GULF THROUGH THAT TIME FRAME. THURSDAY THROUGH FRIDAY AFTERNOON
WENT WITH A GFS/ECMWF BLEND AS BOTH MODELS HAVE BEEN CONSISTENT
BRINGING THE NEXT SYSTEM THURSDAY AFTERNOON INTO THE DIXON
ENTRANCE AREA. THIS IS WHERE THE MODEL AGREEMENT ENDS. THE
OVERALL UPPER LEVEL PATTERN BEGINS TO CHANGE AS MUCH MORE DYNAMIC
SYSTEMS APPROACHES THE PANHANDLE BY EARLY SATURDAY WITH STRONG
UPPER LEVEL JET SUPPORT. TOO EARLY TO TELL EXACTLY HOW STRONG
THIS SYSTEM WILL BE AT THE MOMENT AS THE MODELS HAVE BEEN
FLIP-FLOPPING BUT GALES AND SNOW AMOUNTS BEAR WATCHING INTO THIS
WEEKEND ESPECIALLY IF A FRONTAL BOUNDARY FORMS ACROSS THE
NORTHERN PANHANDLE. AFTER THIS WEEKEND UPPER LEVEL SOUTHWEST FLOW
RETURNS TO THE PANHANDLE WITH ABOVE AVERAGE PRECIPITATION AND
TEMPERATURES EXPECTED INTO EARLY NEXT WEEK.

.AJK...WATCHES/WARNINGS/ADVISORIES
PUBLIC...SNOW ADVY FOR AKZ017 THRU THIS EVNG.
      ...WND ADVY FOR AKZ026>029 THRU TUE AM.

MARINE...GALE WRNG FOR PKZ036-041>043-051-310.
      ...SCA FOR REST OF CSTL WTRS.