Small Craft Advisory 902, NWS Anchorage, AK

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
300 PM AKST SAT NOV 7 2009

.MODEL DISCUSSION...MODELS ARE DOING WELL IN THE GULF REGION THROUGH
TUE NIGHT AND THEN THE GFS AN ECMWF BEGIN TO DIFFER ON THE STRENGTH
AND TIMING OF THE WAVES MOVING THROUGH THE AREA. THINGS ARE MUCH MORE
UNSETTLED WITH THE MODELS IN THE BERING SEA REGION...ESPECIALLY IN
THE NORTHERN BERING SEA AND INTO SOUTHWEST ALASKA. THERE WILL BE A
COUPLE OF LOWS IN THE NORTHERN BERING SEA SUNDAY THROUGH MONDAY NIGHT
AND THE MODELS REMAIN UNSETTLED ON HOW TO RESOLVE THEM.

.ANALYSIS AND UPPER LEVELS...AN UPPER LEVEL LOW CENTERED IN THE
NORTHEAST GULF OF ALASKA WILL REMAIN NEARLY STATIONARY THROUGH MONDAY
NIGHT. THE SURFACE MANIFESTATION OF THIS LOW IS SEEN ON VISIBLE
SATELLITE IMAGERY SOUTH OF YAKUTAT. MOST OF THE BERING SEA REMAINS
UNDER THE INFLUENCE OF AN UPPER LEVEL AND SURFACE RIDGE THAT IS
CAUSING GUSTY NORTHWEST WINDS AND SNOW SHOWERS OVER THAT AREA. THERE
IS A SHORT WAVE JUST NORTHEAST OF DUTCH HARBOR THAT CAN BE SEEN ON
SATELLITE IMAGERY AS WELL.
WHILE THE MAIN PART OF THE JET STREAM IS SOUTH OF THE GULF OF ALASKA
THERE IS A JET STREAK COMING OUT OF EASTERN RUSSIA AND OVER THE
BERING SEA THAT LINKS UP WITH THE MAIN JET SOUTH OF THE ALASKA
PENINSULA. THIS JET WILL BECOME MORE ZONAL OVER THE NEXT TWO DAYS AND
A COUPLE OF LOWS WILL MOVE ALONG IT OUT OF EASTERN RUSSIAN AND
THROUGH THE NORTHERN BERING SEA.

.SHORT TERM FORECAST...GUSTY NORTHWEST WINDS WILL PERSIST OVER MOST
OF THE MARINE AREAS WITH SNOW SHOWERS IN THE BERING SEA AND OVER THE
CENTRAL ALEUTIAN ISLANDS EASTWARD TOWARD KODIAK ISLAND. THE SHORT
WAVE NORTH OF DUTCH HARBOR WILL ENHANCE THE SNOW SHOWERS THERE THIS
EVENING.
CLOUDS IN THE COOK INLET REGION AND INTO A LARGE PART OF THE SUSITNA
VALLEY HAVE PACKED UP ALONG THE MOUNTAINS TO THE EAST AND ARE NOT IN
A BIG HURRY TO CLEAR OUT. THIS SHOULD HELP KEEP OUT ANY FOG...BUT
STRATUS IS A DEFINITE POSSIBILITY. THE AREAS ALONG THE NORTH GULF
COAST SHOULD REMAIN MOSTLY CLEAR TONIGHT WITH THE STRONG OFF SHORE
FLOW.

.LONG TERM FORECAST...TOWARD THE MIDDLE TO LATER PART OF NEXT WEEK
THE OVERALL PATTERN SHOWN BY NUMEROUS MODELS ARE SIMILAR. THERE WILL
BE VERY COLD AIR ALOFT SWEEPING INTO THE SOUTHERN PART OF THE STATE.
BOTH GFS AND ECMWF HAVE 500 MB TEMPERATURES COLDER THAN 40 BELOW OVER
THE ANCHORAGE AREA BY LATE NEXT WEEK. COMBINE THAT WITH A FEW LOWS
MOVING INTO THE NORTHERN GULF OR PRINCE WILLIAM SOUND AND THE FRONTAL
ZONE SETS UP OVER THE COOK INLET AREA. THIS BRINGS A GOOD CHANCE OF
SNOWFALL IN THE COOK INLET THROUGH SUSITNA VALLEY REGIONS BETWEEN
WEDNESDAY NIGHT AND FRIDAY NIGHT. THE DETAILS AS TO EXACTLY WHEN
SNOWFALL SHOULD OCCUR ARE NOT EASILY SEEN THIS FAR OUT...THE OVERALL
PATTERN IS FAVORABLE DURING THAT PERIOD.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE 130 132 150 155 170 171 185.
FIRE WEATHER...NONE.

NOV 09