ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 143 PM EST MON JAN 04 2016 VALID 12Z FRI JAN 08 2016 - 12Z TUE JAN 12 2016 ...GUIDANCE AND UNCERTAINTY ASSESSMENT... THE WPC ALASKAN MEDIUM RANGE PRODUCT SUITE WAS PRIMARILY DERIVED FROM A 50-50 BLEND OF REASONABLY COMPATABLE GUIDANCE FROM THE 06 UTC GEFS MEAN AND 00 UTC ECMWF ENSEMBLE MEAN. THE MID-LARGER SCALE FLOW PATTERN EVOLUTION CONTNIUES TO BE WELL DOCUMENTED IN GUIDANCE OVERALL...SUGGESTING DECENT PREDICTABILITY. HOWEVER...RECENT DETERMINISTIC MODEL RUN TO RUN CONTINUITY HAS BEEN LESS THAN STELLAR THROUGH MEDIUM RANGE TIME SCALES...ESPECIALLY WITH FLOW EMBEDDED SURFACE BASED SYSTEM TIMING/EMPHASIS. DETERMINISTIC MODEL GUIDANCE DOES THOUGH SHOW SUPPORT POTENTIAL FOR DEEPER SURFACE LOW DEVELOPMENT OVER WATER THAN PRODUCED BY THE WPC ENSEMBLE MEAN BLEND. ACCORDINGLY...WPC MANUAL MODIFICATIONS WERE APPLIED TO MAINTAIN LOW DEPTH AND ALSO AS MUCH WPC MEDIUM RANGE CONTINUITY OVER THE ENTIRE FORECAST DOMAIN AS FEASIBLE. ...WEATHER PATTERN HIGHLIGHTS/THREATS... GUIDANCE CONTINUES TO FEATURE DEVELOPMENT AND MAINTANANCE OF AMPLIFIED/BLOCKY MID-UPPER LEVEL FLOW AROUND AK. THE PATTERN IS HIGHLIGHTED BY A MEAN RIDGE EXTENDING FROM WRN CANADA NWWD ACROSS MUCH OF AK. IN THIS PATTERN A MEAN CLOSED LOW/TROUGH HOLDS OVER THE SW/SRN BERING SEA WHILE A SLOW AND STEADY TRANSFER OF AMPLE LOW/TROUGH ENERGIES ROTATING AROUND THE FEATURE TRACK UNDERNEATH THE RIDGE FROM ALONG/S OF THE ALEUTIANS INTO THE WRN GULF OF AK AND INTO SW AK. AN UNSETTLED WEATHER PATTERN WITH PERSISTENT BOUTS OF MODESTLY HEAVY PRECIPITATION REMAINS HELD MAINLY OVER THE SRN BERING/ALEUTIANS AND SW/SRN AK AS FUELED BY PERSISTENT WRAPPING INFLOW AND FOCUSING BUT HARD TO TIME DEEPENED LOW APPROACH AND PASSAGE. SCHICHTEL