ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 337 PM EDT MON OCT 05 2015 VALID 12Z FRI OCT 09 2015 - 12Z TUE OCT 13 2015 THE ALASKA MEDIUM RANGE FORECAST REMAINS CONSISTENT WITH AN APPROACH THAT ANCHORS A BROAD CYCLONE IN THE NORTHWEST GULF OF ALASKA. THIS CYCLONE AND THE ENTIRE PATTERN LOOKS ACTIVE ACROSS THE GULF OF ALASKA AND COAST/COASTAL INTERIOR...BUT NOT 'UNSEASONAL' FOR MID-OCTOBER ACROSS THE NORTHEAST PACIFIC THROUGH DAY 8. THE 5/00Z ECENS AND 5/06Z GEFS MEANS WERE VERY REASONABLE PLACEHOLDERS THROUGH THE PERIOD---BUT THE DETERMINISTIC 5/00Z ECMWF AND 5/00Z GFS STRUGGLED WITH THE NORTHEASTWARD MIGRATION OF TS 'OHO'. LOOKED LIKE THE CPHC FORECAST GENERALLY FOLLOWS A SLOWER GFS (5--00Z/06Z/12Z) APPROACH WITH A POSITION NEAR 40N 134W AT 10/12Z. THE WPC SURFACE GRAPHIC FOR 10/12Z HAS THE COLD FRONT ALONG 140W WHICH ALLOWS ENOUGH ROOM FOR SOME TROPICAL CONNECTION TO WORK NORTHWARD INTO THE PANHANDLE UNTIL DAY 6. SO I AM COMFORTABLE WITH THE ENSEMBLE 'MEAN' SOLUTION TO HANDLE THE GENERAL PATTERN. THIS TROPICAL FORECAST TRACK LINES UP OKAY---BUT NOT PERFECT---WITH A 'STOUT' SHORTWAVE I HAD KEYED IN ON 3-4 DAYS AGO...IN THE SAME GENERAL AREA. THE OUTCOME HERE ---WITH RESPECT TO SURFACE LOW POSITION ---IS WHERE THE GFS/ECMWF DO---REMAIN VERY DIFFERENT---AND WHY THE 5/06Z GEFS AND 5/00Z ECENS WERE REASONABLE. THE 5/00Z-5/12Z DETERMINISTIC ECMWF SOLUTIONS WOULD LIKELY BRING THE SYSTEM (OR AT THE VERY LEAST---A SOUTH WIND) INTO THE EASTERN GULF AND SOUTHERNMOST PANHANDLE)---A GOOD 12-18 HOURS QUICKER THAN THE GFS. SO THERE IS A BIT MORE ADJUSTMENT "POSSIBLE" BETWEEN LATE THURSDAY AND FRIDAY AFTERNOON FOR THIS 'STOUT' SHORTWAVE'S APPROACH. A SECOND REASON TO UTILIZE AN ENSEMBLE MEANS (PRIMARILY AN ECENS APPROACH) TODAY---IS THE DIFFERENT DETERMINISTIC SOLUTIONS UPSTREAM WITH THE INCLUSION OF 'CHOI-WAN' INTO THE NORTHERN STREAM. THE ENSEMBLE MEANS RELEASE THE SYSTEM DOWNSTREAM ON/AROUND 11/12Z. AT THIS TIME FRAME UNTIL 13/00Z---THE 5/12Z ECMWF RELEASES IT DOWNSTREAM OFF THE SOUTHERN KAMCHATKA PENINSULA AND TOWARDS THE WESTERN ALEUTIANS. THE 5/12Z GFS CURLS IT NORTHWARD ALONG THE EAST COAST OF KAMCHATKA AND DEEPENS THE SURFACE LOW TO 959MB INVOF 58N 170E. AN OBSERVATIONAL NOTE... MENTIONED YESTERDAY THAT I HOPED WE WOULD GET 'A GLIMPSE' OF THE FIRST DECENT WAVE TRAIN---AN EARLY WET-SEASON WEATHER PATTERN SET UP ALONG AND WEST OF THE DATELINE BY PERIOD'S END. THE 5/12Z GFS WOULD SAY NO---TO THAT IDEA. BUT NOT THE 5/12Z ECMWF---SO IT STILL IS WORTH 'WATCHING FOR' IN THE DAY 7-9 PERIOD WEST OF THE DATELINE. VOJTESAK