ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 249 PM EST TUE NOV 07 2017 VALID 12Z SAT NOV 11 2017 - 12Z WED NOV 15 2017 MODELS/ENSEMBLES REMAIN IN VERY GOOD SYNOPTIC AGREEMENT AND EVEN GOOD AGREEMENT ON THE DETAILS, CONSIDERING THE LEAD TIME. UPPER RIDGING IS NOT TO BE DENIED OVER THE BERING SEA AND DESPITE A STRONG NORTHERN STREAM SHORTWAVE OR WEAKLY CLOSED LOW MOVING OUT OF NORTHEASTERN RUSSIA AND THROUGH THE CHUKCHI SEA (TEMPORARILY KNOCKING DOWN THE RIDGE) THE PATTERN WILL RE-ESTABLISH ITSELF WITH THE RIDGE/TROUGH OVER THE BERING/GULF. MODELS HAVE BEEN RATHER STEADY OVER THE PAST FEW RUNS WITH A POTENT SFC LOW MOVING INTO NW ALASKA BEFORE TRANSLATING EASTWARD AND SOUTHWARD TO RE-EMERGE OVER THE GULF WHILE DRAGGING A COLD FRONT THROUGH THE INTERIOR. SEEMS AS IF THE SYSTEM MAY SPLIT AROUND THE BROOKS RANGE AS THE UPPER SUPPORT EITHER DROPS SOUTHEASTWARD (ECMWF) OR SPLITS N-S (GFS) TO CARRY THE OLD SFC LOW EASTWARD INTO THE NW YUKON. THE NEW SFC LOW IN THE GULF WILL CONTINUE TO TRACK SOUTHEASTWARD PARALLEL TO THE SE COAST AND HELP DRAG IN COLDER AIR FROM CANADA ON EASTERLY WINDS ACROSS THE PANHANDLE. BLEND OF THE RECENT 12Z/06Z GFS WITH THE 00Z ECMWF OFFERED A GOOD STARTING POINT NEAR CONTINUITY TO START, BUT THEN DECREASED THE GFS WEIGHTING EARLIER THAN THE OTHERS ON ACCOUNT OF ITS DIFFERENT HANDLING OF THE SYSTEM TO THE SOUTHEAST OF THE ALEUTIANS NEXT WEEK COMPARED TO THE RATHER AGREEABLE GEFS/ECMWF ENSEMBLES AND 00Z ECMWF. THAT SYSTEM MAY CREEP INTO THE ALEUTIANS MIDWEEK NEXT WEEK UNDERNEATH THE LARGER HEIGHT ANOMALIES IN THE BERING. PRECIPITATION WILL FOCUS OVER NORTHWESTERN ALASKA AND INTO THE BROOKS RANGE AS SW FLOW AHEAD OF THE COLD FRONT MEETS THE HIGHER TERRAIN. QPF PER GEFS M-CLIMATE LIES IN THE 99TH PERCENTILE JUST EAST OF KOTZEBUE SOUND. DRIER CONDITIONS SHOULD PREVAIL BY THE END OF THE PERIOD OVER MUCH OF THE MAINLAND AS HIGH PRESSURE EDGES INTO THE AREA. COLDER THAN AVERAGE TEMPERATURES WILL SPREAD INTO MUCH OF THE INTERIOR AND SOUTHEAST ALASKA NEXT WEEK. FRACASSO