MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1211 AM EDT SUN MAY 08 2016 VALID MAY 08/0000 UTC THRU MAY 11/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z GFS/NAM EVALUATION WITH PRELIMINARY MODEL PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ GFS/NAM INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. SYSTEM SWINGING THROUGH THE NORTHWEST/NORTHERN PLAINS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GFS/ECMWF COMPROMISE CONFIDENCE: NO BETTER THAN AVERAGE THE LATEST RUNS OF THE GFS (00Z) AND ECMWF (12Z) ARE MAKING THE 06/12Z UKMET RUN LOOK TERRIFIC IN HAVING A MORE SOUTHERLY CLOSED MID-LEVEL CYCLONE NEAR THE WY/MT BORDER THEN INTO THE NORTHERN PLAINS. THE 12Z ECMWF ENSEMBLE MEAN MATCHES THIS SOLUTION. THE 12Z CANADIAN/12Z UKMET ARE MORE NORTHERLY AND STRONGER AT 700 HPA. THE PATTERN IN WHICH THIS SYSTEM IS EMBEDDED FEATURES AT LEAST THREE OTHER SYSTEMS, THOUGH THIS SYSTEM IS THE LARGEST/STRONGEST AND IS DOWNSTREAM OF BUILDING RIDGING IN THE NORTHEAST PACIFIC. THIS CHANGE IN THE 00Z GFS MAY HERALD SIMILAR CHANGES IN LATER ARRIVING 00Z GUIDANCE, SO WILL PREFER A 00Z GFS/12Z ECMWF COMPROMISE TO GET AHEAD OF THE GAME WITH CONFIDENCE NO BETTER THAN AVERAGE. DEEP CYCLONE MOVING INTO MIDWEST MON/TUES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-CANADIAN COMPROMISE CONFIDENCE: SLIGHTLY ABOVE AVERAGE THE 12Z CANADIAN IS THE FARTHEST SOUTHEAST WITH THIS SYSTEM IN THE UPPER MIDWEST, WHICH IN THE SURFACE PATTERN TUESDAY MORNING LIES EAST OF ALL THE 12Z GLOBAL ENSEMBLE GUIDANCE. OTHERWISE, THE GUIDANCE IS RATHER SIMILAR. A COMPROMISE OF THE 00Z GFS/00Z NAM/12Z UKMET/12Z ECMWF IS ADVISED WITH SLIGHTLY ABOVE AVERAGE CONFIDENCE. TROUGHING RELOADING OVER THE NORTHEAST ON SUN ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ THE GUIDANCE SHOWS EXCELLENT AGREEMENT WITH THIS SYSTEM. A GENERAL MODEL COMPROMISE IS ADVISED 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