MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 237 AM EDT FRI OCT 09 2015 VALID OCT 09/0000 UTC THRU OCT 12/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z MODEL EVALUATION WITH PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. SYSTEM MOVING NEAR THE US/CANADIAN BORDER LATE SAT-MON AM ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GFS/ECMWF/NAM COMPROMISE CONFIDENCE: ABOVE AVERAGE THE 00Z UKMET IS A QUICK OUTLIER WITH THIS SYSTEM -- ITS USUAL BIAS. THE 00Z CANADIAN DEVELOPS AN EXTRA AREA OF LOW PRESSURE NEAR DULUTH MN MONDAY MORNING, WHICH ONLY A HANDFUL OF THE 90 12Z GLOBAL ENSEMBLE MEMBERS SUPPORT. A COMPROMISE OF THE 00Z GFS/00Z NAM/00Z ECMWF APPEARS BEST HERE WITH ABOVE AVERAGE CONFIDENCE. SYSTEM NEAR THE SOUTHEAST SAT INTO MON ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GFS/ECMWF/CANADIAN COMPROMISE CONFIDENCE: ABOVE AVERAGE THE 00Z NAM TAKES ITS SURFACE LOW MORE NORTHEAST OF THE OTHER GUIDANCE, WHICH COULD BE DUE TO GRIDSCALE FEEDBACK. THE 00Z UKMET IS THE MOST OPEN ALOFT BUT THE SLOWEST WITH ITS PROGRESSION, WHICH WAS AN ABRUPT CHANGE IN ITS CONTINUITY. OTHERWISE, DIFFERENCES ARE MINIMAL BETWEEN THE 00Z GFS/00Z ECMWF/00Z CANADIAN; A COMPROMISE OF THE THREE IS PREFERRED WITH ABOVE AVERAGE CONFIDENCE. SYSTEMS MOVING BY WESTERN CANADA FRI/SAT UPPER LOW DROPPING THROUGH NORTHWEST MEXICO SYSTEM MOVING THROUGH THE NORTHEAST LATE FRIDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE GUIDANCE IS IN GOOD AGREEMENT WITH THESE SYSTEMS. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ROTH