EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 256 AM EDT WED NOV 01 2017 VALID 12Z SAT NOV 04 2017 - 12Z WED NOV 08 2017 ...COLDER AND STORMY FOR THE WEST... ...GUIDANCE/UNCERTAINTY ASSESSMENT AND WEATHER/THREAT HIGHLIGHTS... THE LATEST 12Z GFS/ECMWF/ECMWF ENSEMBLE MEAN AND 18Z GFS/GEFS MEAN OFFERED A REASONABLE STARTING POINT TO THE FORECAST. TRENDED AWAY FROM THE 12Z GFS/ECMWF MID-PERIOD DUE TO UNCERTAINTY IN HOW QUICKLY THE UPPER TROUGH PROGRESSES THROUGH CANADA (TREND HAS BEEN QUICKER) AND HOW A SECONDARY SHORTWAVE MODULATES THE WESTERN TROUGH AROUND MONDAY. BY NEXT TUE/WED, 18Z GFS AND 12Z ECMWF FELL BACK IN LINE WITH THEIR ENSEMBLE MEANS AS YET ANOTHER UPPER LOW LOOKS TO RELOAD THE WESTERN TROUGH JUST OFF THE PAC NW COAST. THE EAST SHOULD THEN SEE LOWERING HEIGHTS AS THE UPPER RIDGE REMAINS OVER MEXICO. PRECIPITATION SHOULD FOCUS ALONG THE WAVY BOUNDARY AND SFC LOW THAT LIFTS THROUGH THE GREAT LAKES SUN/MON AND THEN SETTLES INTO THE SOUTHEAST TUE/WED. THE WEST STANDS TO SEE APPRECIABLE PRECIPITATION NEARLY EVERYWHERE OUTSIDE THE LOWER DESERTS OF AZ. THE SIERRAS AND CENTRAL ROCKIES COULD SEE SEVERAL FEET OF SNOW OVER THE COURSE OF THE WEEK. FRACASSO