ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 337 PM EDT FRI OCT 06 2017 VALID 12Z TUE OCT 10 2017 - 12Z SAT OCT 14 2017 LEAD SYSTEMS SPREAD LINGERING UNSETTLED CONDITIONS AND SWATHS OF MODEST PCPN WITHIN A NRN STREAM OVER WRN/NRN AK AND A SRN STREAM FROM SE AK TO WRN CANADA. THESE LEAD SYSTEMS LOSE INFLUENCE OVER ALASKAN WEATHER AFTER THE EXTENDED HOLIDAY WEEKEND. MODEL AND ENSEMBLE SPREAD INCREASES SIGNIFICANTLY NEXT WEEK SO FORECAST UNCERTAINTY REMAINS ABOVE NORMAL. HOWEVER...GUIDANCE DOES OFFER A GOOD LARGER SCALE SIGNAL FOR DEEP BERING SEA LOW GENESIS NEXT WEEK WITH STEADY FLOW AMPLIFICATION. THE EMERGENCE OF A POTENT LOW INTO THE BERING SEA AND APPROACH TOWARD THE ALASKAN MAINLAND SETS THE STAGE FOR A PROLONGED PERIOD OF HIGHLY UNSETTLED MARITIME CONDITIONS...WITH HEAVY PCPN SPREADING INLAND ACROSS THE ALEUTIANS TO WRN/SWRN AK...INTO THE INTERIOR... AND THEN SRN AK HEADING INTO NEXT WEEKEND AS THE MAIN LOW ROLLS EASTWARD AND MODEST TRIPLE POINT LOW DEVELOPMENT OCCURS DOWNSTREAM TO SUBSEQUENTLY WORK ACROSS THE NRN GULF OF AK. MAX CONTINUITY AND SYSTEM CLUSERING SEEMS TO BEST FAVOR A SOLUTION MOST IN LINE WITH THE 00 UTC ECMWF ENSEMBLE MEAN AND TO A LESSER EXTENT THE 12 UTC GEFS MEAN DAYS 4-8. ACCORDINGLY...THESE GUIDANCE PIECES WERE PRIMARILY USED TO DETERMINE WPC ALASKAN SURFACE FRONTS/PRESSURES...500MB PROGS...AND HIGH RESOLUTION SENSIBLE WEATHER GRIDS. SCHICHTEL