MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 231 AM EDT FRI MAY 06 2016 VALID MAY 06/0000 UTC THRU MAY 09/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z NAM/GFS EVALUATION INCLUDING PRELIMINARY MODEL PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ GFS/NAM INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. SYSTEM MOVING INTO THE NORTHWEST SUNDAY NIGHT ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-NAM COMPROMISE CONFIDENCE: ABOVE AVERAGE THE 00Z NAM IS THE SLOWEST WITH THIS SYSTEM'S PROGRESSION -- ITS USUAL BIAS. PREFER A QUICKER CONSENSUS OF THE 00Z GFS/12Z CANADIAN/12Z UKMET/12Z ECMWF WITH ABOVE AVERAGE CONFIDENCE. DEEP CYCLONE MOVING INTO THE PLAINS SUN NIGHT/MONDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: AVERAGE DESPITE SMALL DIFFERENCES AT 500 HPA AND 700 HPA WITH THIS SYSTEM, THE SURFACE PATTERN IS REMARKABLY CLOSE AMONGST THE DETERMINISTIC/ENSEMBLE MEAN GUIDANCE. TO DEAL WITH THE DIFFERENCES ALOFT, PREFER A COMPROMISE OF THE 00Z GFS/00Z NAM/12Z UKMET/12Z CANADIAN/12Z ECMWF WITH AVERAGE CONFIDENCE. DEEP CYCLONE MOVING TOWARD ME SUN NIGHT/MON MORNING ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: CLOSEST TO THE UKMET CONFIDENCE: AVERAGE THERE ARE STRENGTH ISSUES WITH A CLOSED CYCLONE EVOLVING OVER ATLANTIC CANADA SUNDAY NIGHT/MORNING MORNING, WITH THE 00Z GFS THE STRONGEST OF THE GUIDANCE AND THE 12Z CANADIAN THE WEAKEST. THE 12Z UKMET MAKES FOR A GOOD COMPROMISE ALOFT AND WITH ITS SURFACE LOW DEVELOPMENT AND FRONTAL TIMING, SO IT IS PREFERRED WITH AVERAGE CONFIDENCE. TROUGH SWINGING OFFSHORE THE EAST COAST FRI NIGHT/SAT ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ THE GUIDANCE SHOWS GOOD AGREEMENT WITH THIS FEATURE, SO WE FAVOR A GENERAL MODEL COMPROMISE WITH ABOVE AVERAGE CONFIDENCE TO DEAL WITH ANY LINGERING DETAIL ISSUES. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ROTH