MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 226 AM EDT FRI OCT 21 2016 VALID OCT 21/0000 UTC THRU OCT 24/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z NAM/GFS EVALUATION INCLUDING THE UKMET/CANADIAN/ECMWF AND PREFERENCES LOW PRESSURE INFLUENCING THE NORTHEAST/NEW ENGLAND THROUGH SATURDAY... PREFERENCE: EQUAL BLEND GFS/ECMWF CONFIDENCE: AVERAGE THE GFS AND ECMWF SHOW SUFFICIENTLY CLOSE AGREEMENT WITH EACH OTHER AND ARE WELL ENCOMPASSED BY THEIR RESPECTIVE ENSEMBLE MEMBERS TO SUPPORT THEM EQUALLY. CONFIDENCE IS ABOUT AVERAGE GIVEN THE MODEST SIZE OF THE SOLUTION ENVELOPE. THUS...EQUAL WEIGHTING OF THE GFS/ECMWF SHOULD SUFFICE. THE NAM IS COMPETITIVE THROUGH 12Z SAT...BEFORE DRIFTING TOWARD THE SLOW SIDE OF THE GUIDANCE. LOW PRESSURE NEARING THE NORTHWEST COAST SUNDAY NIGHT... PREFERENCE: GEFS MEAN OR 12Z ECMWF ENSEMBLE MEAN CONFIDENCE: AVERAGE SPREAD IS AVERAGE FOR PLACEMENT AND DEPTH OF THE LOW...WITH THE ENSEMBLE MEANS MOST PREFERRED TO ADDRESS THE UNCERTAINTY. THE ECMWF LIES NEAR THE DEEP EDGE OF THE GUIDANCE BY 12Z MONDAY...WITH THE NAM CLOSEST TO THE ECMWF ENSEMBLE MEAN...AND THE GFS/GEFS MEAN CLOSEST TO THE CONSENSUS. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... JAMES