MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1224 AM EDT MON MAY 09 2016 VALID MAY 09/0000 UTC THRU MAY 12/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z GFS/NAM EVALUATION AND PRELIMINARY MODEL PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ GFS/NAM INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. UPPER LOW IN BRITISH COLUMBIA WEDNESDAY TROUGHING LIFTING OUT OF NEW ENGLAND ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ THE GUIDANCE SHOWS GOOD AGREEMENT WITH THESE SYSTEMS. A GENERAL MODEL COMPROMISE SHOULD DEAL WITH ANY LINGERING DETAIL ISSUES EFFECTIVELY, WHICH IS PREFERRED WITH ABOVE AVERAGE CONFIDENCE. UPPER TROUGH PULLING INTO THE PLAINS TUESDAY/WEDNESDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GFS/NAM/ECMWF COMPROMISE CONFIDENCE: AVERAGE THE 12Z CANADIAN/12Z UKMET ARE MORE CLOSED WITH ENERGY EMERGING OUT OF THE NORTHERN ROCKIES WEDNESDAY, AND END UP WITH SURFACE LOWS NEAR OR OUTSIDE THE 12Z GLOBAL ENSEMBLE LOW ENVELOPE. A COMPROMISE OF THE 00Z GFS/00Z NAM/12Z ECMWF APPEARS BEST HERE, WITH AVERAGE CONFIDENCE CONSIDERING THE MODEL SPREAD. FOR RAINFALL FORECAST CONSIDERATIONS, SEE OUR QPF DISCUSSION FOR MODEL CHOICES FROM THAT VANTAGE POINT. SYSTEM MOVING THROUGH THE MIDWEST TUESDAY/WEDNESDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-UKMET COMPROMISE CONFIDENCE: ABOVE AVERAGE DESPITE A SIMILAR SOLUTION AT 500 HPA AND 700 HPA, THE 12Z UKMET STRAYS FROM THE PACK WITH ITS SURFACE LOW BEHAVIOR, ENDING UP FASTER THAN THE REMAINDER OF THE DETERMINISTIC/AND WITHIN AN AREA OF MINORITY MEMBERSHIP OF THE 12Z GLOBAL ENSEMBLE LOW ENVELOPE. PREFER A COMPROMISE OF THE 00Z NAM/00Z GFS/12Z ECMWF/12Z CANADIAN WITH ABOVE AVERAGE CONFIDENCE. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ROTH