ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 329 PM EDT MON SEP 29 2014 VALID 12Z FRI OCT 03 2014 - 12Z TUE OCT 07 2014 SYNOPTIC PATTERN ACROSS THE HIGH LATITUDES SHOULD FEATURE TROUGHING OVER THE SEA OF OKHOTSK THAT PROGRESSES SLOWLY EASTWARD... RIDGING OVER THE BERING SEA... AND TROUGHING OVER THE INTERIOR THAT WILL ONLY GRADUALLY RETREAT EASTWARD INTO NW CANADA. OVER THE N PACIFIC... SYSTEMS SHOULD BE FAVORED TO TRAVEL IN THE 40-50N LATITUDE BELT WITH A LEAD SYSTEM TAKING AIM ON THE SOUTHERN PANHANDLE. POTENTIAL EXISTS FOR A RATHER DEEP CYCLONE IN THE SE GULF TO START THE MEDIUM RANGE PERIOD... FRI 3 OCT... BUT THIS IS DEPENDENT ON HOW THE REMNANTS OF TROPICAL STORM KAMMURI GET ENTRAINED /IF AT ALL/ INTO THE UPPER LOW MOVING INTO THE GULF IN THE SHORT TERM. THE 12Z GFS/ECMWF KEEP THE TWO ENTITIES JUST SEPARATED ENOUGH TO PREVENT A DEEP / <970MB / STORM... BUT OTHER RUNS PLUS MANY ENSEMBLE MEMBERS STILL INDICATE THAT CHANCE AND IT WOULD NOT TAKE MUCH IN NUDGING THE TIMING/AMPLITUDE TO DEVELOP A STRONG SYSTEM. THE 00Z ECMWF ENSEMBLE MEAN OFFERED A MOST REASONABLE SOLUTION IN BOTH DEPTH AND PLACEMENT AND ITS FORECAST WAS USED AS A BASE FOR THE PERIOD. HEAVY RAIN IS STILL FORECAST FOR THE CENTRAL/SOUTHERN PANHANDLE BUT THAT WILL BE DEPENDENT ON THE DETAILS YET TO BE RESOLVED. THEREAFTER... FOCUS WILL TURN TO THE WESTERN BERING SEA WITH AN APPROACHING UPPER/SFC LOW. ENSEMBLE MEANS HAVE BEEN FAIRLY CONSISTENT FOR SEVERAL RUNS... BUT BY NEXT WEEK THE EXTRATROPICAL TRANSITION OF TS PHANFONE /LIKELY TO BECOME A TYPHOON/ WOULD ADD ANOTHER CURVE BALL TO THE FORECAST. FOR NOW... A BLEND OF THE ENSEMBLE MEANS WILL SUFFICE GIVEN THE LEAD TIME. SFC LOW SHOWN ON THE PROGS ON TUE/D8 IS THE FORECAST POSITION OF THE REMNANT LOW... WHICH HAS BEEN FORECAST AS LOW AS THE 940S MB BY SOME MODELS INCLUDING THE 12Z GFS AND NOW IN THE 950S MB BY THE 12Z ECMWF /FROM BASICALLY NOTHING IN ITS 00Z RUN/. FRACASSO