Small Craft Advisory 1053, NWS Anchorage, AK

AREA FORECAST DISCUSSION...CORRECTED
SOUTHCENTRAL AND SOUTHWEST ALASKA
1235 PM AKST SUN DEC 27 2009

CORRECTED TYPO

.ANALYSIS AND UPPER LEVELS...LONG-WAVE TROUGH EXTENDS FROM ASIA
ACROSS MOST OF THE NORTH PACIFIC AND ALASKA...WITH EASTERN AREAS
OF ALASKA ON THE WEST PERIPHERY OF A BLOCKING RIDGE CENTERED OVER
ALBERTA CANADA. A LARGE UPPER LOW CENTERED OVER THE NORTH-CENTRAL
PACIFIC WITH THREE SURFACE LOW EMBEDDED WITHIN ITS CIRCULATION.
THE ONLY LOW OF SIGNIFICANCE IS A GALE FORCE LOW TRACKING NORTHWARD
UP THE EAST SIDE OF THE TROUGH TOWARD THE ALASKA PENINSULA AND
EASTERN ALEUTIANS. ELSEWHERE ACROSS THE REGION WEAK UPPER LEVEL
SHORT-WAVES CONTINUE TO FOCUS SHOWERS. A FEW DAYS OF SOUTHEASTERLY
FLOW ACROSS THE GULF AND SOUTHERN MAINLAND INTO THE EASTERN BERING
HAS WARMED THE LOW LEVELS ENOUGH TO PRODUCE MAINLY RAIN.

.MODEL DISCUSSION...THE GFS IS THE OUTLIER WITH TRACK OF THE PACIFIC
LOW...SO WILL STICK WITH THE CONSENSUS OF THE ECMWF/NAM/UKMET
SOLUTIONS. MODELS DO DIFFER WITH FORMATION AND TRACK OF TRIPLE
POINT LOWS DOWNSTREAM OF THIS FIRST LOW...BUT THEY SHOULD REMAIN
SOUTH OF THE GULF WITH LITTLE OR NO IMPACT ON THE FORECAST AREA.

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...A WEAK UPPER SHORT-WAVE WILL TRACK NORTHWARD
ACROSS SOUTHCENTRAL TONIGHT AND INTO THE INTERIOR ON
MONDAY...BRINGING A CONTINUED CHANCE OF SHOWERS ACROSS THE REGION.
SLIGHTLY COOLER AIR WILL ADVECT IN ALOFT...SO WILL START TO SEE
SOME SNOW MIX BACK IN WITH THE RAIN. AREAS WHICH OBSERVE SHOWERS
TONIGHT WILL HAVE GOOD POTENTIAL FOR FOG MONDAY MORNING AS THE
MID TO UPPER LEVELS CLEAR OUT...LEAVING BEHIND LOW-LEVEL MOISTURE.
HIGH PRESSURE WILL THEN BUILD IN BEHIND THE SHORT-WAVE ON TUESDAY
AND LOW LEVEL FLOW WILL TOWARD THE NORTH (A DRIER OFFSHORE
FLOW)...RESULTING IN A DRYING TREND. HIGH PRESSURE WILL REMAIN
IN CONTROL THROUGH AT LEAST MID WEEK. THE COMBINATION OF PARTLY
CLOUDY TO MOSTLY CLEAR SKIES COMBINED WITH THE LIKELIHOOD OF
ADVECTION OF COLDER AIR FROM THE NORTH WILL PRODUCE A COOLING
TREND AS WE HEAD THROUGH THE NEXT FEW DAYS. THE ONE EXCEPTION TO
THE DRIER AND COOLER WEATHER IS KODIAK ISLAND WHICH WILL CONTINUE
TO SEE CLOUDS AND PERIODS OF RAIN AS A FRONT BECOMES NEARLY
STATIONARY JUST TO THE SOUTH OF THE ISLAND.

SOUTHWEST ALASKA...SIMILAR TO SOUTHCENTRAL...UPPER SHORT-WAVE WILL
MOVE THROUGH TONIGHT. HOWEVER...ON MONDAY THE OCCLUDED FRONT
EXTENDING FROM NORTH PACIFIC LOW WILL APPROACH THE SOUTHWEST COAST
AND THEN REMAIN NEARLY STATIONARY THROUGH TUESDAY. THIS WILL BRING
WIND AND POSSIBLY SOME RAIN TO THE IMMEDIATE COAST. IT LOOKS LIKE
THE BULK OF THE RAIN WILL STAY OFFSHORE...SO ANYTHING THAT DOES
FALL WILL BE LIGHT. MEANWHILE...INLAND AREAS WILL SEE A DRYING AND
COOLING TREND AS HIGH PRESSURE BUILD OVERHEAD.

BERING SEA/ALEUTIANS/ALASKA PENINSULA...THE PACIFIC LOW WILL BRING
ANOTHER ROUND OF RAIN AND WINDS TO THE EASTERN BERING REGION...WITH
SOME BANDS OF PRECIPITATION SPREADING FURTHER WESTWARD ALONG THE
OCCLUDED FRONT. THE LOW WILL BE FORCED WESTWARD ACROSS THE BERING
TUESDAY AND WEDNESDAY AS THE UPPER RIDGE BUILDS ACROSS MAINLAND
ALASKA INTO THE NORTHERN BERING.

.LONG TERM FORECAST...MEDIUM RANGE MODELS SHOW SOME CONSISTENCY
IN UPPER RIDGE RETROGRADING TO NEAR THE BERING STRAIT AND ALLOWING
SOME ARCTIC AIR TO PLUNGE SOUTHWARD ACROSS THE EASTERN MAINLAND
LATE THIS WEEK. IF SO...THIS WOULD BE A GOOD SET-UP FOR STRONG
NORTHERLY WINDS. OTHERWISE...IT LOOKS LIKE CALM WEATHER AND
SEASONABLE TEMPERATURES WILL DOMINATE THE MAINLAND. THE SUBTROPICAL
JET LOOKS LIKE IT WILL REMAIN WELL SOUTH OF THE FORECAST AREA...SO
DONT EXPECT ANY MAJOR STORMS ACROSS THE BERING SEA AND ALEUTIANS
THROUGH THE END OF THE WEEK...ALTHOUGH MAY SEE SOMETHING ROTATE
NORTHWARD BY THE WEEKEND.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING...130 132 138 150 155 160 165 170 180.
         HEAVY FREEZING SPRAY WARNING...185.
FIRE WEATHER...NONE.

SEB DEC 09