ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 341 PM EDT THU JUN 04 2015 VALID 12Z MON JUN 08 2015 - 12Z FRI JUN 12 2015 ...PATTERN OVERVIEW AND SENSIBLE WEATHER THREATS/HIGHLIGHTS... AN UNSETTLING MID-UPPER LEVEL MEAN TROUGH FROM THE BERING STRAIGHT TO THE ARCTIC IS UNDERCUT BY AMPLIFIED PACIFIC TROUGH ENERGY OVER THE ALEUTIANS AND S-CENTRAL BERING SEA EARLY NEXT WEEK. ACTIVITY SPREADS INCREASINGLY INTO WRN/SWRN AK AND THE GULF OF AK AND INTO SRN/SERN AK NEXT WEEK. AN ASSOCIATED SURFACE LOW PRESSURE SYSTEM TRACK AND LEAD FLOW SHOULD BE THE PRIMARY FOCUS FOR ORGANIZED AND TERRAIN ENHANCING PRECIPITATION. IN THIS PATTERN...AMPLIFYING AND WARMING DOWNSTREAM RIDGING POKES NORTHWESTWARD FROM NW CANADA INTO THE ERN ALASKAN INTERIOR. ...GUIDANCE/UNCERTAINTY ASSESSMENT... THE WPC MEDIUM-RANGE PRODUCT SUITE HAS BEEN PRIMARILY DERIVED FROM A BLEND OF THE 00 UTC ECMWF ENSEMBLE MEAN AND 00 UTC NAEFS ENSEMBLE MEAN. THE NAEFS IS A BIAS CORRECTED COMBINATION OF THE GEFS AND CANADIAN ENSEMBLE MEANS. SMALLER INPUT FROM THE REASONABLY COMPATABLE 00 UTC ECMWF DETERMINITSIC MODEL WAS ALSO INCLUDED IN THE WPC SOLUTION INTO TUE/WED TO PROVIDE SLIGHTLY BETTER DETAIL IN A PERIOD OF LOWERED FORECAST SPREAD/HIGHER PREDICTABILITY. SCHICHTEL