Small Craft Advisory 364, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM ADT WED APR 18 2007

.MODEL DISCUSSION...MODELS IN GOOD AGREEMENT REGARDING PRIMARY LOW
CENTERS. HOWEVER SIGNIFICANT DISAGREEMENT BETWEEN GFS AND NAM
REGARDING TRIPLE POINT LOW NEAR KODIAK ISLAND. GFS BARELY RECOGNIZES
A CLOSED CENTER AND TRACKS IT DIRECTLY OVER THE ISLAND. NAM PEGS IT
AT 996 MB AND KEEPS IT WELL SOUTH OF KODIAK ISLAND. UKMET IS SIMILAR
TO NAM BUT WITH A CENTRAL PRESSURE OF 992 MB. NAM SOLUTION IS MOST
CONSISTENT WITH 12Z ANALYSIS SO IS PREFERRED SOLUTION THROUGH 60
HOURS.

.UPPER LEVELS...HIGH AMPLITUDE RIDGE OVER MAINLAND ALASKA AND GULF OF
ALASKA WILL GRADUALLY WEAKEN AND SHIFT EASTWARD INTO WESTERN CANADA
BY FRIDAY AFTERNOON. UPPER LEVEL LOW ANCHORED OVER THE RUSSIAN FAR
EAST WILL REPOSITION ITSELF OVER THE CHUKCHI SEA BY FRIDAY MORNING.
MEANWHILE A SERIES OF WEAK UPPER LEVEL LOWS WILL MIGRATE WEST TO EAST
ALONG THE ALEUTIAN CHAIN AND UP THE BERING COAST. PATTERN IS
CONDUCIVE FOR

.SURFACE FEATURES...
OLD BERING LOW NOW CENTERED JUST OFF THE KUSKOKWIM DELTA COAST WILL
MOVE NORTHWARD INTO THE CHUKCHI SEA BY LATE WEDNESDAY NIGHT.
BLIZZARD CONDITIONS HAVE ABATED ALL AREAS. RAIN WILL BE THE DOMINATE
PRECIP TYPE TODAY OVER SOUTHWESTERN ALASKA.

ASSOCIATED TRIPLE POINT LOW WILL TRACK JUST SOUTH OF KODIAK ISLAND
AND INTO THE NORTH PACIFIC BY WEDNESDAY EVENING. RAINFALL SPREADING
ACROSS KODIAK ISLAND THIS MORNING AND ACROSS THE KENAI PENINSULA BY
EVENING. GUSTY SOUTHEAST WINDS THROUGH PORTAGE VALLEY AND TURNAGAIN
ARM WILL DIMINISH LATE TONIGHT.

A 974 MB LOW 600 NM SOUTHWEST OF SHEMYA WILL MOVE TO 200 NM SOUTH OF
SAND POINT AT 984 MB THURSDAY NIGHT THEN GRADUALLY WEAKENS AND DRIFTS
SOUTHEASTWARD. STRONG SOUTHEAST TO NORTHAST WINDS TODAY AND TONIGHT
FROM DUTCH HARBOR TO SHEMYA. UPPER LEVEL PATTERN IS CONDUCIVE TO
SURFACE LOWS TRACKING ALONG OR JUST TO THE SOUTH OF THE ALEUTIAN
CHAIN. UNLIKELY TO SEE ANOTHER MAJOR BERING LOW FOR SOME TIME.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE
MARINE...GALE  130 155 160 165 170 171 172 175 176 180
         SPRAY 185
FIRE WEATHER...NONE

ASB APR 07