Small Craft Advisory 126, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
519 AM AKST TUE FEB 10 2015

.ANALYSIS AND UPPER LEVELS...
A DEEP LOW SITS TO THE SOUTH OF THE ALASKA PENINSULA AND IS ON A
SLOW TRACK NORTH. THE FRONT ASSOCIATED WITH THIS LOW HAS ALREADY
MOVED INTO THE EASTERN BERING AND IT EXTENDS EAST OVER KODIAK
ISLAND AND OUT OVER THE SOUTHERN GULF WITH A FAIR AMOUNT OF WARM
AIR COMING UP BEHIND IT. OUT WEST HIGH PRESSURE SITS OVER
NORTHEASTERN RUSSIA WHICH AIDS IN BRINGING NORTHEASTERLY FLOW TO
MUCH OF THE BERING.

&&

.MODEL DISCUSSION...
THE MODELS ARE IN DECENT AGREEMENT IN THE SHORT TERM. THE BIGGEST
ISSUE IS WITH THE FORMATION OF A TRIPLE POINT LOW IN THE GULF THIS
AFTERNOON. ODDLY ENOUGH YESTERDAY THE ONLY MODEL WITH A CLOSED
CIRCULATION FOR THIS LOW WAS THE NAM AND TODAY IT IS THE LAST
MODEL TO MAKE IT A CLOSED CIRCULATION. THAT BEING SAID...ITS
TIMING IS IN LINE WITH BOTH THE EC AND GFS. HOWEVER THE GEM IS
FURTHER WEST THAN THE OTHERS.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (DAYS 1 AND 2)...

A WEATHER FRONT OVER THE SOUTHERN GULF MOVES NORTH TODAY. A WAVE
DEVELOPS ALONG THE FRONT THIS AFTERNOON AND INTENSIFIES AS IT
MOVES INTO THE NORTHERN GULF WED. GALES TO STORM FORCE WINDS ARE
EXPECTED IN ADVANCE OF THE FRONTAL SYSTEM AND ASSOCIATED WAVE.
WINDS SHOULD DIMINISH IN MOST AREAS WED AS THE FRONT WEAKENS AND
THE WAVE MOVES INLAND. SNOW WITH A RAIN MIX IS EXPECTED ALONG THE
GULF COAST AND EASTERN KENAI TODAY THROUGH WED AS THE FRONT AND
WAVE PUSH NORTH. SNOW TODAY WEST OF THE KENAI/CHUGACH/TALKEETNA
MOUNTAINS SHOULD BE FAIRLY LIGHT TO FLURRIES THROUGH TONIGHT. SNOW
SHOULD PICK UP IN THESE AREAS ON WED/WED NIGHT AS THE WAVE
RETROGRADES NW ACROSS THE AREA. THERE COULD ALSO BE SOME MIXED
PRECIPITATION TYPES.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (DAYS 1 AND 2)...
PRECIPITATION OVER THE SOUTHWEST MAINLAND WILL BE LARGELY
CONFINED TO THE BRISTOL BAY REGION THROUGH WEDNESDAY...WITH A
STALLED FRONT OVER THE SOUTHEASTERN BERING AND A WEAK UPPER WAVE
ROTATING NORTHWESTWARD ACROSS THE ALASKA PENINSULA KEEPING A
CHANCE OF SNOW OVER THE AREA FOR THE NEXT SEVERAL DAYS. THE
KUSKOKWIM VALLEY AND DELTA WILL SEE MOSTLY CLOUDY SKIES AS THE
UPPER LEVEL FEATURE PASSES TO THE SOUTH...BUT WILL OTHERWISE STAY
MOSTLY DRY WITH GUSTY NORTHEAST WINDS OVER THE DELTA IN PERSISTENT
OFFSHORE FLOW. A BETTER CHANCE FOR PRECIPITATION ACROSS THE ENTIRE
AREA WILL OCCUR WEDNESDAY NIGHT AS ANOTHER UPPER WAVE LIFTS
NORTHWARD FROM THE PACIFIC.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (DAYS 1 AND 2)...
THE STALLED FRONT OVER THE SOUTHEASTERN BERING WILL KEEP RAIN AND
GUSTY NORTHEAST WINDS OVER THE ALASKA PENINSULA AND EASTERN
ALEUTIANS FOR THE NEXT SEVERAL DAYS AS IT SLOWLY WEAKENS IN PLACE.
ELSEWHERE...A TIGHT PRESSURE GRADIENT BETWEEN A RIDGE OVER THE
WESTERN BERING AND THE BROAD NORTH PACIFIC LOW WILL HELP TO
MAINTAIN A LARGE SWATH OF GALE FORCE WINDS OVER THE CENTRAL BERING
INCLUDING THE PRIBILOF ISLANDS AND CENTRAL ALEUTIANS THROUGH THE
MIDDLE OF THE WEEK.

&&

.LONG TERM FORECAST (DAYS 3 THROUGH 7)...SOUTHERLY FLOW BETWEEN A
LARGE UPPER LEVEL RIDGE OVER THE WESTERN US AND CANADA AND A BROAD
UPPER LEVEL LOW CENTERED SOUTH OF THE TIP OF THE ALASKA PENINSULA
WILL BRING A SERIES OF FRONTAL WAVES INTO THE GULF OF ALASKA FROM
THROUGH AROUND SATURDAY. THE LARGE NUMBER OF FRONTAL WAVES
PUSHING UP OVER THE AREA WILL BRING A DEFINITE WARMING TREND WITH
NUMEROUS OPPORTUNITIES FOR PRECIPITATION. CURRENTLY PRECIPITATION
TYPES ARE LOOKING TO BE PREDOMINATELY RAIN IMMEDIATELY ALONG THE
GULF COAST CHANGING OVER TO SNOW NOT FAR INLAND. AS THE WARMING
PROGRESSES THROUGH THE END OF THE WEEK SOME ISOLATED FREEZING RAIN
MAY STILL BE POSSIBLE IN COLD WIND SHELTERED VALLEYS...BUT THE
POTENTIAL FOR WIDESPREAD IMPACTS CONTINUES TO BE TRENDING
GRADUALLY DOWN FROM PREVIOUS MODEL RUNS.

IN THE MORE EXTENDED TIME PERIODS MODELS ARE NOW SUGGESTING A
SECOND PATTERN SHIFT WITH A LARGE NEGATIVELY TILTED UPPER LEVEL
RIDGE BUILDING OVER THE GULF OF ALASKA AROUND SUNDAY WITH A COUPLE
OF STRONG LOWS SPINNING UP ALONG ITS SOUTHWEST SIDE AND TRACKING
TO THE WEST SOUTHWEST BETWEEN 40N AND 50N SOUTH OF THE ALEUTIANS.
FOR SOUTHCENTRAL ALASKA THE POSITION OF THIS RIDGE WOULD START A
DRYING TREND WHILE WARM AND PERIODICALLY WET SOUTHEASTERLY FLOW
WOULD BE DIRECTED AT KODIAK ISLAND...SOUTHWEST ALASKA AND THE
ALASKA PENINSULA WITH VARIOUS SURFACE LOWS TRACKING WEST DOWN THE
ALEUTIANS.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...STORMS 130 138
         GALES 119 120 127 131 132 136 137 139 150 160 165 170
               173-181 185
         HEAVY FREEZING SPRAY 126 127 139 179 185
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...DK
SOUTHCENTRAL ALASKA...RMC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CB
LONG TERM...JR