Small Craft Advisory 94, NWS Anchorage, AK

AREA FORECAST DISCUSSION SOUTHWEST ALASKA
1200 PM AST FRI JAN 28 2005

.DISCUSSION...

MODELS INITIALIZED POSITION OF STRONG PACIFIC LOW AT 500NM SOUTH OF
DUTCH HARBOR.  GFS HAS BEST CENTER PRESSURE AT 955 MB WHICH IS
CLOSEST TO THE 12Z NCEP SURFACE ANALYSIS OF 957 MB.  WAVE MODEL IS
GIVING 40 FOOT PLUS SEA HEIGHTS SOUTH OF LOW WITH GALE WINDS BEING
REPORTED THIS MORNING BY NEARBY SHIPS.  HOWEVER HIGHEST SEAS FROM
THIS LOW..AND A SPIN-OFF SECONDARY LOW..IS FORECASTED TO STAY OUT OF
THE ANCHORAGE AOR.

UPPER FEATURES MATCH UP WELL ON MODELS WITH HIGH PRESSURE PERSISTING
OVER EASTERN RUSSIA AND MAIN UPPER LOWS IN THE NORTH PACIFIC AND OVER
NORTHERN CANADA.  GFS AND ETA HAVE SIMILAR SOLUTIONS THROUGH 60HRS
WITH UPPER HIGH PRESSURE ANCHORED OVER EASTERN RUSSIA AND UPPER LOW
PRESSURE ANCHORED OVER NORTHERN CANADA.  AS WE GO THROUGH 60HRS TWO
UPPER LOWS BECOME PROMINENT IN THE NORTH PACIFIC..ONE SOUTH OF THE
ALASKA PENINSULA AND ANOTHER SOUTH OF THE GULF OF ALASKA.  THE LOW
SOUTH OF THE GULF OF ALASKA IS SUPPORTED BY A SHIFT IN THE JET STREAM
SATURDAY NIGHT WHICH TAKES IT OVER THE NORTHEAST GULF COAST AT 72HRS.

ONE THING OF CONCERN WITH MODELS IS THE POOR INITIALIZATION OF THE
SPIN-OFF LOW JUST WEST OF THE PANHANDLE.  GFS MISSES IT WHILE THE ETA
HINTS AT IT IN THE PRECIPITATION AND MSL PRESSURE FIELDS.  BOTH GFS
AND ETA BACK PRECIPITATION OFF FROM PREVIOUS MODEL RUN AND DOESNT
BRING IT IN ACROSS PRINCE WILLIAM SOUND UNTIL TONIGHT AND THE KENAI
PENINSULA UNTIL SATURDAY.  SATELLITE AND RADAR IMAGERY CURRENTLY
SUPPORTS THIS AS ARCTIC FRONT REMAINS SOUTH OF PRINCE WILLIAM SOUND
AND THE KENAI PENINSULA WHICH WILL KEEP THIS LOW IN THE EASTERN GULF
THROUGH THIS EVENING. NEXT FORECAST PACKAGE WILL BE ADJUSTED
ACCORDINGLY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES...3AC 5B 6AB 12A.  HVY RRZ SPRAY...6A 8 14.

JWP JAN 05