Small Craft Advisory 81, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKST SAT JAN 25 2014

.ANALYSIS AND UPPER LEVELS...
CLEARING SKIES AND SUBSIDENCE WITH WEST BUILDING RIDGE ALLOWED FOR
THE FORMATION OF STRATUS AND FOG OVER THE COPPER RIVER BASIN AND
PORTIONS OF THE UPPER COOK INLET/AND NORTH GULF. EASTERLY FLOW OVER
THE WESTERN GULF CONTINUED LOW CLOUDS AND SOME LIGHT RAIN OVER KODIAK
ISLAND. A WEATHER FRONT WAS MOVING WEST ACROSS THE AK PEN/EASTERN
BERING SEA AFTERNOON. SNOW WAS EVIDENT ALONG AND TO THE WEST OF THE
BOUNDARY. SNOW COMBINED WITH STRONG NORTHERLY WINDS WERE CAUSING NEAR
BLIZZARD CONDITIONS OVER UNALASKA. SNOW TURNED TO RAIN NEAR COLD BAY
THIS MORNING.

IN THE UPPER LEVELS...
THE MEAN POSITION OF THE LOW COMPLEX SOUTH OF THE EASTERN
ALEUTIANS/WESTERN AK PEN SHIFTS SLIGHTLY EAST MON. SEVERAL
CYCLONICALLY ROTATING WAVES WITH THIS FEATURE MOVE ACROSS THE GULF
AND THE SOUTHERN MAINLAND AND PENETRATE RATHER EAST AND NORTH AS THE
RIDGE OVER THE GULF/EASTERN MAINLAND MOVES EAST. THE RIDGE ACROSS THE
NORTH PACIFIC BUILDS OVER THE CENTRAL BERING SEA SUN/MON AS COLD AIR
SPILLING SOUTH OUT OF RUSSIA DIGS THE LONG WAVE NEAR THE SEA OF
OKHOTSK/KAMCHATKA. THIS SETS UP A STRONG SW JET WHICH FEEDS THE
DEVELOPMENT OF A SURFACE LOW WHICH MOVES TO THE WESTERN BERING SEA
MON AFTERNOON WITH A PRESSURE IN THE 960S.

.MODEL DISCUSSION...THE GLOBAL MODELS ALL ARE IN FAIR AGREEMENT IN
THE OVERALL SYNOPTIC PATTERN. THE ECMWF HAS BEEN THE MOST CONSISTENT
AND OVERALL APPEARS TO BE THE BEST CHOICE. THOUGH IT DOES STRUGGLE
WITH A SECONDARY LOW DEVELOPMENT WHICH MOVES TO THE EASTERN BERING
SEA LATE MON NIGHT. THE GFS/GEM HAVE A BETTER HANDLE ON THIS FEATURE.
THE TIMING OF FRONTAL TROUGHS ARE IN FAIRLY GOOD AGREEMENT BETWEEN
THE ECMWF/GFS THROUGH THE SHORT TERM.

.SHORT TERM FORECAST...

.SOUTHCENTRAL ALASKA...
PATCHY FOG IS EXPECTED ACROSS THE COPPER RIVER BASIN AGAIN TONIGHT
AND A FEW AREAS INLAND. OTHER THEN THAT...THE MAIN AREAS OF LOWER
CLOUDS AND FOG WILL BE ASSOCIATED WITH A FRONTAL TROUGH WHICH TRACKS
NORTH ACROSS THE GULF TONIGHT/SUN. THE BRUNT OF THE RAIN ASSOCIATED
WITH THIS FEATURE WILL IMPACT MOSTLY THE WESTERN GULF AND KENAI PEN.
A SECONDARY FRONT WHICH MOVES NORTH ACROSS THE GULF MON WILL HAVE A
GREATER EASTWARD EXTENT AS THE GULF RIDGE SHIFTS EAST. THE LIONS
SHARE OF THE RAIN WITH THESE SYSTEMS WILL BE ALONG THE COAST/SE
EXPOSURES AS DOWN SLOPE SHOULD MINIMIZE RAIN POTENTIAL INLAND.
PRESSURE GRAIDENTS WILL INCREASE WITH NORTH MOVEMENT OF FRONTAL
TROUGHS AND AS LOWS MOVE TOWARD THE EASTERN BERING SEA THROUGH MON
AND PRODUCE PERIODS OF STRONG GAP WINDS INLAND AND GALE TO STRONG
FORCE WINDS IN MARINE AREAS. TEMPERATURES SHOULD REMAIN RELATIVEY
MILD WITH GENEARLLY HIGH FREEZING LEVELS THROUGH EARLY NEXT WEEK.

BERING SEA AND ALEUTIANS...
THE WEATHER FRONT EXTENDING NORTH ACROSS THE EASTERN ALEUTIANS/EAST
BERING SEA WILL SHIFTS WEST OF UNALASKA AND THE PRIBILOFS THEN SLOWLY
WEAKEN THROUGH SUN NIGHT. SNOW AND BLOWING SNOW WILL BE SHIFTING WEST
OF UNALASKA LATE THIS AFTERNOON AS TEMPS WARM ACROSS UNALASKA. SNOW
OVER THE PRIBILOF ISLANDS SHOULD BE CHANGING OR MIXING WITH RAIN THIS
EVENING THEN DIMINISHING AS THE FRONT MOVES WEST OVERNIGHT. A SECOND
AND WEAKER FRONTAL TROUGH MOVES IN FROM THE SOUTH AND EAST SUN
EVE/NIGHT AND BRINGS ANOTHER CHANCE OF RAIN/SNOW TO THE EASTERN
BERING. A DEVELOPING NORTH PACIFIC LOW MOVES TO THE WESTERN BERING
SEA MON AFTERNOON. ITS FRONTAL TROUGH MOVES TO JUST WEST OF 180 BY
MON AFTERNOON. EXPECT INCREASED CHANCES OF RAIN AND SNOW AND STRONG
SOUTHERLY WINDS WITH THIS SYSTEM.

SOUTHWEST ALASKA...THE WEATHER FRONT OVER THE DELTA MOVES WEST THIS
EVENING WITH SOME CLOULD BREAKS TO FOLLOW. A SECOND AND WEAKER FRONT
MOVES IN FROM THE SOUTH SUN AND BRINGS SOME LOW QPF RAIN AND
SNOW/SHOWERS. STRONG CROSS BARRIER FLOW SHOULD MINIMIZE PRECIPITATION
INLAND. LOOK FOR STRONG WINDS NEAR CHANNELED AND EXPOSED TERRAIN
THROUGH MON AFTERNOON. RELATIVELY MILD TEMPERATURES WILL CONTINUE
THROUGH THE WEEKEND.

.LONG TERM FORECAST...
EXTENDED GUIDANCE STILL STRUGGLING WITH THE BREAKDOWN OF THE
PERSISTENT EAST PACIFIC RIDGE. DETERMINISTIC MODELS STILL BREAKING
THE RIDGE DOWN EARLY NEXT WEEK AND CLOSING OFF AN UPPER HIGH
OVER THE YUKON AND MIGRATING IT SOUTHWARD. THE RESULT WOULD BE
SLIGHTLY COOLER TEMPERATURES THAN WE HAVE BEEN EXPERIENCING BUT MUCH
DRIER AND LESS WINDY.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...STORMS...131 138
         GALES...119 120 125 130 132 129 141 351 352 150 155 160 165
                 170 171 172 173 174 175 176 178 180 181

FIRE WEATHER...NONE.

RMC JAN 14