MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1220 PM EDT WED JUL 15 2015 VALID JUL 15/1200 UTC THRU JUL 19/0000 UTC ..SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z GFS/NAM EVALUATION WITH PRELIMINARY MODEL PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NAM/GFS INITIALIZATION ERRORS DO NOT APPEAR TO IMPACT THEIR SHORT TERM FORECASTS. DEEP CYCLONE MOVING ACROSS SOUTHWEST CANADA DIGGING TROUGH IN THE WEST SATURDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GFS/ECMWF/CANADIAN COMPROMISE CONFIDENCE: SLIGHTLY ABOVE AVERAGE THE 00Z UKMET/12Z NAM ARE QUICKER/STRONGER WITH THE ENERGY ALOFT -- THEIR RESPECTIVE BIASES --SKIRTING THE US/CANADIAN BORDER. DESPITE THESE ISSUES, THEY LOOK SIMILAR TO THE OTHER GUIDANCE IN THE SURFACE PATTERN AND SHOW PLAUSIBLE SOLUTIONS WITH THE TROUGH DIGGING INTO THE NORTHWEST. THE 12Z GFS IS WEAKER THAN ITS 06Z MEAN, SO IT IS NOT PREFERABLE ON ITS OWN. A COMPROMISE OF THE 12Z GFS/00Z ECMWF/00Z CANADIAN APPEARS IDEAL WITH SLIGHTLY ABOVE AVERAGE CONFIDENCE. SHORTWAVES/LOW MOVING THROUGH THE GREAT LAKES LOW LIFTING BY NEW ENGLAND TODAY/EARLY THU ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE GUIDANCE SHOWS REASONABLE AGREEMENT WITH THESE FEATURES. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ROTH