Small Craft Advisory 23, NWS Anchorage, AK

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKST MON JAN 6 2014

.MODEL DISCUSSION...
THE STRONG NORTH PACIFIC JET IS STILL PRODUCING MODEL TIMING AND
POSITIONAL DIFFERENCES THROUGH THE SHORT TERM. THE ECMWF HAS BEEN
SOMEWHAT MORE CONSISTENT ON THE MOVEMENT OF THE LOW INTO THE SE GULF
ON WED. THE GEM IS ALSO TRENDING THAT WAY. THE NAM/GFS ARE PUTTING
MOVE EMPHASIS ON TRACKING THE LOW FURTHER WEST AND NORTH. THE MODELS
ARE IN BETTER AGREEMENT OVER THE BERING SEA...THOUGH THE ECMWF IS
STILL THE FAVORED SOLUTION.

.ANALYSIS AND UPPER LEVELS...
A WAVE EXTENDING FROM SW ALASKA...ACROSS COOK INLET AND THE GULF IS
MOVING RAPIDLY NORTH AND EAST THIS AFTERNOON. PRECIPITATION HAS
DIMINISHED TO MAINLY SHOWERS ACROSS SW ALASKA...WITH A FEW AREASS OF
LIGHT FREEZING RAIN STILL EXPECTED OVER THE KUSKOKWIM VALLEY THROUGH
THIS AFTERNOON. SNOW AND RAIN ASSOCIATED WITH THIS WAVE ACROSS
SOUTHCENTRAL IS MAINLY CONFINED ALONG THE TROUGH AXIS AND SKIES ARE
RAPIDLY CLEARING ON THE BACKSIDE ACROSS NORTH COOK INLET. RAIN AND
SNOW ALONG THE GULF SHOULD BE TAPERING OFF AS THE TROUGH MOVES
THROUGH THIS TONIGHT.

.SHORT TERM FORECAST...
.SOUTHCENTRAL ALASKA...
RAIN AND SNOW WILL TAPER OFF FROM THE SOUTH AND WEST THROUGH TONIGHT.
CLEARING SHOULD FOLLOW BUT WILL BE SOMEWHAT SLOWER ACROSS THE GULF AS
SOME STRATUS WILL LIKELY REMAIN WITH SUBSIDENCE ON THE BACKSIDE OF
THE THROUGH. A WEAKER TROUGH MOVES TO SOUTHCENTRAL/GULF ON TUE. THE
FRONT OF PRECIPITATION...RAIN AND SNOW WILL BE CONFINED MAINLY TO THE
COASTS. WINDS ACROSS TURNAGAIN ARM SHOULD DIMINISH BELOW STRONG WIND
BY EVENING WITH TROUGH PASSAGE. TEMPS WILL COOL SOME SOME AFTER TROGH
PASSAGE TONIGHT...BUT SHOULD REMAIN ON THE MILD SIDE THROUGH MID
WEEK. WEAK UPPER WAVES MOVING ACROSS THE REGION WILL CONTINUE THE
THREAT OF RAIN OR SNOW THROUGH WED.

SOUTHWEST ALASKA...
THE WAVE OVER THE KUSKOKWIM VALLEY WILL CLEAR THE AREA LATE THIS
AFTERNOON AND END THE FREEZING RAIN THREAT. A FRONTAL TROUGH MOVING
NORTH ACROSS THE AK PEN WILL BRING ANOTHER SHOT AT RAIN AND SNOW TO
TO THE REGION WITH THE MAIN THREAT OF FREEZING RAIN POTENTIAL OVER
THE KUSKOKWIM DELTA. TEMPERATURES IN GENERAL ARE RELATIVELY MILD AND
THE ONSET OF STRONG SE WINDS IN THE LOWER LEVELS AND COLD COVER
SHOULD KEEP TEMPS UP THROUGH TONIGHT. SO THE THINKING FOR NOW IS TO
KEEP A MENTION OF ISOLATED AREAS OF LIGHT FREEZING ON THE DELTA.
PRECIPITATION SHOULD BE MIXED OVER THE BRISTOL BAY ZONE. DOWNSLOPE
OVER THE KUSKOKWIM VALLEY SHOULD MITIGATE AN SIGNIFICANT
PRECIPITATION POTENTIAL ON TUE. BRISK SOUTHEASTERLY FLOW IS EXPECTED
ACROSS BRISTOL BAY AND THE DELTA TONIGHT THROUGH TUE. WINDS SHOULD
DIMINISH ACROSS MUCH OF THE AREA THROUGH WED.

BERING SEA REGION...

LOW PRESSURE AND ASSOCIATED FRONTAL SYSTEM WILL CONTINUE TO MOVE
NORTH TO NORTHEAST ACROSS THE REGION FROM THE EASTERN ALEUTIANS
THROUGH THE EASTERN HALF OF THE BERING SEA THROUGH TUESDAY NIGHT. AS
THE LOW MOVES NORTH AND WEST OF UNALASKA/DUTCH HARBOR THIS EVENING
THE STORM WILL BEGIN TO RAPIDLY OCCLUDE WHICH COULD ALLOW FOR A
PERIOD OF MUCH STRONGER WINDS BRIEFLY IN THIS PARTICULAR AREA. A
PERIOD OF STEADY RAIN CAN BE EXPECTED ALONG THE FRONT AND AHEAD OF
THE LOW FROM SAINT PAUL TO UNALASKA EAST. HOWEVER...FOR POINTS WEST
LOW LEVEL THICKNESSES WILL SUPPORT THE POTENTIAL FOR RAIN MIXING WITH
WET SNOW IN THE SHOWER ACTIVITY...WITH THE BEST CHANCE TOWARD THE
WESTERN ALEUTIANS AND NORTHERN AND WESTERN BERING WHERE LOW-LEVEL
THICKNESSES WILL FALL BELOW THE 1290 METER LEVEL AT TIMES THROUGH MID
WEEK.

.LONG TERM FORECAST...

MODELS CONTINUE TO BE IN FLUX WITH THE LONG-TERM SYNOPTIC
PATTERN...BUT THE TREND CONTINUES TOWARD RETROGRADING UPPER LEVEL
HIGH PRESSURE OVER THE ARCTIC OCEAN NORTH OF ALASKA MOVING TO NORTH
OF EASTERN SIBERIA...ALLOWING FOR INCREASED NORTHERLY TO
NORTHEASTERLY FLOW INTO THE NORTHERN PART OF THE STATE. WHEREAS
YESTERDAY MODELS WANTED TO PUSH THIS FLOW/SYSTEM SOUTH ALL THE WAY
THROUGH SOUTHERN ALASKA...TRENDS ARE NOW SUGGESTING THAT THE
ASSOCIATED UPPER LEVEL FEATURE WILL SLIDE SOUTH AND WEST AND MERGE
WITH THE EXISTING UPPER LEVEL LOW OVER THE BERING SEA AND THUS
REINFORCE THE BERING SEA LOW/TROUGH. THIS WOULD IN TURN REINFORCE
UPPER LEVEL RIDGING TOWARD THE GULF OF ALASKA AND THE
PANHANDLE/WESTERN CANADA AND BRING A CONTINUATION OF SOUTHWEST FLOW
WITH MORE NORMAL 850-MB TEMPERATURES TO MUCH OF SOUTHERN ALASKA FOR
THIS WEEKEND INTO EARLY NEXT WEEK. HOWEVER...UNCERTAINTY STILL
REMAINS HIGH WHILE MODEL SOLUTIONS REMAIN IN FLUX SO STAY TUNED.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES 150 160 170 172 174 180 414
FIRE WEATHER...NONE.

RMC JAN 14