Small Craft Advisory 850, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
500 AM ADT SAT OCT 13 2007

.MODEL DISCUSSION...00Z MODELS SHOW BETTER AGREEMENT IN THE SHORT
TERM THAN IN PREVIOUS RUNS BUT THE TRACK OF THE LOW IN THE NORTHERN
GULF OF ALASKA IS STILL A MAJOR CONCERN. RUN TO RUN CONSISTENCY
REMAINS POOR IN THE MID TO LONG TERM ESPECIALLY IN THE EAST. ONLY
MODERATE CHANGES TO THE FORECAST PACKAGE MADE BEYOND MONDAY DUE TO
LOW MODEL CONFIDENCE IN THE MID TO LONG TERM.

.SOUTH AND EAST OF THE ALASKA RANGE...
974 MB LOW IN THE NORTHERN GULF ABOUT 90 NM SOUTHEAST OF SEWARD WILL
MOVE INLAND TODAY. BEST BET IS THAT IS THAT IT WILL BE POSITIONED
ABOUT 60 NM NORTHWEST OF ANCHORAGE BY SUNDAY EVENING. ACCORDING TO
THE GFS A SECONDARY LOW MAY DEVELOP JUST SOUTH OF SEWARD SUNDAY
EVENING BUT HIGHER RESOLUTION NAM KEEPS THE ENERGY WITH THE PRIMARY
LOW. EITHER WAY THIS IS A GOOD SNOW PATTERN FOR ANCHORAGE. MIXED
PRECIPITATION IS A POSSIBILITY FOR AREAS NORTH OF THE CHUGACH AND
EAST OF THE KENAI RANGE ESPECIALLY DURING THE OVERNIGHT AREAS.
HOWEVER LOW LEVEL COLD AIR ADVECTION BEHIND THE SURFACE LOW COUPLED
WITH WARM AIR AND MOISTURE ADVECTION IN THE MID TO UPPER LEVELS
SHOULD KEEP SNOW THE DOMINANT PRECIPITATION TYPE FOR THE ANCHORAGE
BOWL AS WELL AS THE MATSU VALLEY AND THE COPPER RIVER BASIN.

.SOUTHWESTERN MAINLAND...BROAD NORTHEASTERLY FLOW ACROSS THE
KUSKOKWIM VALLEY KUSKOKWIM DELTA AND BRISTOL BAY TODAY WILL SHIFT TO
THE NORTHWEST TONIGHT. EXPECTED COOLER TEMPERATURES AND SCATTERED
SNOW SHOWERS.

.OUT WEST...A SMALL 992 MB LOW 240 NM WEST OF SHEMYA THIS MORNING
ASSOCIATED WITH A BIG STORM COMPLEX OVER KAMCHATKA AND THE KURIL
ISLANDS WILL BECOME THE PRIMARY LOW BY THIS EVENING. THE LOW RAPIDLY
INTENSIFIES TO 979 MB AS IT MOVES INTO THE WESTERN SEA TONIGHT. THE
LOW THEN TRAVERSES THE SOUTHERN BERING SEA SUNDAY CROSSES OVER THE
ALASKA PENINSULA SUNDAY EVENING AND INTO THE NORTH PACIFIC MONDAY
MORNING. EXPECT STORM FORCE WESTERLIES ALONG THE SOUTHERN FLANK OF
THE LOW. THE ASSOCIATED OCCLUDED FRONT MOVES ACROSS THE WESTERN AND
CENTRAL ALEUTIANS TODAY AND ACROSS THE EASTERN ALEUTIANS TONIGHT. THE
FRONT BEGINS TO DETERIORATE OVER THE ALASKA PENINSULA ON SUNDAY.
PRECIPITATION WILL FALL MAINLY AS RAIN ALONG AND IN ADVANCE OF THE
FRONT BUT EXPECT SCATTERED TO NUMEROUS SNOW SHOWERS IN ITS WAKE.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE  130 155 171.
         STORM 170 172 175 176
FIRE WEATHER...NONE.

ASB OCT 07