MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 237 AM EDT FRI SEP 04 2015 VALID SEP 04/0000 UTC THRU SEP 07/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z MODEL EVALUATION WITH PRELIMINARY MODEL PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. DEEP CYCLONE MOVING INTO SOUTH-CENTRAL CANADA LINGERING TROUGHING ACROSS THE NORTHERN ROCKIES/NORTHWEST ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-NAM COMPROMISE CONFIDENCE: ABOVE AVERAGE FOR SUNDAY, THE 00Z NAM IS SLOW/WEST WITH THE OVERALL SYSTEM MOVING THROUGH/LIFTING OUT OF MT. A COMPROMISE OF THE 00Z UKMET/00Z ECMWF/00Z GFS/00Z CANADIAN FITS IN WELL WITH THE 12Z ECMWF/00Z GEFS MEAN SOLUTIONS, AND IS PREFERRED WITH ABOVE AVERAGE CONFIDENCE. SURFACE LOW MOVING INTO QUEBEC ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GFS/ECMWF COMPROMISE CONFIDENCE: AVERAGE WITH THE APPEARANCE OF THE 00Z UKMET/00Z ECMWF, THE 00Z NAM SOLUTION OF MOVING A SURFACE LOW QUICKER THROUGH QUEBEC HAS SOME ADDITIONAL SUPPORT. IN AN EFFORT TO MAINTAIN SOME CONTINUITY, A COMPROMISE OF THE 00Z GFS/00Z ECMWF IS PREFERRED WITH AVERAGE CONFIDENCE. UPPER LOW RETROGRADING INTO THE SOUTHEAST MID-LEVEL LOW NEAR MI THROUGH SATURDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 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