EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 914 AM EST THU NOV 10 2016 VALID 12Z SUN NOV 13 2016 - 12Z THU NOV 17 2016 GENERAL FLOW PATTERN & MODEL PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ THE GENERAL FLOW PATTERN HAS CHANGED LITTLE OVER THE PAST DAY OF MODEL RUNS, ADDING CONFIDENCE TO THE FORECAST. AN INCREASINGLY AMPLIFIED AND SOMEWHAT PROGRESSIVE PATTERN (THE AMPLIFICATION ANOTHER SOURCE OF FORECAST CONFIDENCE) IS COMPOSED OF TROUGHING OFFSHORE THE WEST, RIDGING IN THE ROCKIES/PLAINS, AND TROUGHING IN THE EAST IS EXPECTED. WHILE THERE ARE SMALL SCALE DETAIL ISSUES AMONGST THE GUIDANCE, THE 00Z UKMET, 00Z CANADIAN, 00Z ECMWF, AND 06Z GFS FOR THE MOST PART SHOWED EXCELLENT AGREEMENT. FOR THE EAST, THE 00Z ECMWF WAS QUICKER TO MOVE A SYSTEM UP THE EAST COAST THAN THE OTHER GUIDANCE -- AGAINST ITS USUAL BIAS. IN CASE THE PATTERN BECOMES MORE AMPLIFIED, WHICH IS POSSIBLE, LOWERED ECMWF WEIGHT WEDNESDAY INTO NEXT THURSDAY. OTHERWISE, FOR PRESSURES/WINDS/500 HPA HEIGHTS, AN EVEN BLEND OF THE 00Z CANADIAN/00Z UKMET/06Z GFS/00Z ECMWF WAS USED FROM SUNDAY INTO TUESDAY, BEFORE USING INCREASING AMOUNTS OF 00Z NAEFS AND 00Z ECMWF ENSEMBLE MEANS IN LIEU OF THE UKMET AND DECREASING AMOUNTS OF THE ECMWF FOR WEDNESDAY AND NEXT THURSDAY. THE TEMPERATURE, DEW POINT, CLOUD, AND PRECIPITATION CHANCE GRIDS WILL BE MORE ENSEMBLE MEAN BASED, AS USUAL. THE QPF FOR DAYS 4-7 IS PLANNED TO BE MOSTLY BASED ON THE 00Z ECMWF AND 06Z GFS. WEATHER HIGHLIGHTS/THREATS ~~~~~~~~~~~~~~~~~~~~~~~~~~ HIGHEST RAIN/HIGHEST ELEVATION SNOW TOTALS FOR THE PERIOD ARE LIKELY TO BE FROM THE PACIFIC NORTHWEST INTO EXTREME NORTHERN CA WITH SOME ENHANCED ACTIVITY EXTENDING INTO THE NORTHERN ROCKIES. THE UPPER TROUGH MOVING INTO THE WEST WILL SPREAD PRECIPITATION INLAND ACROSS THE NORTHERN INTERMOUNTAIN WEST MID NEXT WEEK. SNOW LEVELS WILL DECREASE WITH THE PASSAGE OF THE UPPER TROUGH. MOISTURE SHOULD REACH INTO THE PLAINS NEXT THU. A SFC LOW/FRONTAL SYSTEM MAY GENERATE A PERIOD OF STRONG WINDS OVER PARTS OF THE WEST INTO THE PLAINS. THE NATURE OF EASTERN TROUGHING AND DOWNSLOPED FLOW/FOEHN EAST OF THE ROCKIES WILL LIKELY KEEP ANY RAIN THAT OCCURS WEST OF THE APPALACHIANS AS LIGHT. UNCERTAINTY REMAINS WITH THE EXACT EVOLUTION OF THE DEEP LAYERED CYCLONE/POSSIBLE NOR'EASTER NEAR THE EAST COAST EARLY TO MID NEXT WEEK KEEPS CONFIDENCE NO BETTER THAN AVERAGE FOR THE DAY 3-7 PERIOD FOR RAIN COVERAGE/INTENSITY. IT WILL REMAIN MILD, ALMOST TO THE POINT OF BEING UNSEASONABLY WARM, FROM THE INTERIOR WEST THROUGH THE NORTHERN AND CENTRAL PLAINS/UPPER MISSISSIPPI VALLEY SUN-TUE WITH HIGHS 10-25F ABOVE NORMAL. THIS WARMTH WILL EXTEND BEYOND TUE EAST OF THE ROCKIES BUT THE SYSTEM MOVING INTO/THROUGH THE WEST WILL BRING BELOW NORMAL TEMPS FROM THE WEST COAST TO THE ROCKIES BY WED-THU. MEANWHILE ERN U.S. TEMPS SHOULD BE NEAR TO MODESTLY ABOVE NORMAL MOST DAYS. ROTH/RAUSCH