MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 230 PM EDT FRI JUL 04 2014 VALID JUL 04/1200 UTC THRU JUL 08/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION...INCLUDING THE NAM/GFS/UKMET/GEM AND ECMWF ...HURRICANE ARTHUR... PREFERENCE: 04/15Z NHC FORECAST ADVISORY THE GFS/ECMWF/GEM AND UKMET ARE WELL CLUSTERED WITH THE LATEST OFCL NHC TRACK THROUGH ABOUT 36 HRS. THE NAM CONTINUES TO BE A RELATIVE OUTLIER WITH A TRACK SOMEWHAT SLOWER AND TO THE RIGHT. ...UPPER TROUGH ADVANCING THROUGH THE NORTHEAST THROUGH SAT... PREFERENCE: NON-NAM CONSENSUS CONFIDENCE: ABOVE AVERAGE THE MODELS ARE GENERALLY VERY WELL CLUSTERED WITH THE DETAILS OF THE UPPER TROUGH/HEIGHT FALLS EXPECTED TO ADVANCE EAST OF THE GREAT LAKES/OH VLY AND THROUGH THE NORTHEAST OVER THE NEXT 24 TO 36 HOURS. HOWEVER...THE EXCEPTION IS THE NAM WHICH AT 24 HRS SUGGESTS SHARPER HEIGHT FALLS AND A CLOSED MID LVL LOW CENTER OVER SRN NEW ENGLAND THAT IS SOUTHWEST OF ANY OTHER MODEL. A NON-NAM CONSENSUS WILL BE PREFERRED. ...UPPER TROUGH/COLD FRONT CROSSING THE UPPER MIDWEST AND GREAT LAKES BY SUN AND MON... PREFERENCE: NON-UKMET CONSENSUS CONFIDENCE: AVERAGE THE UKMET IS A FAST OUTLIER WITH THIS ENERGY AND THE ASSOCD COLD FRONT. THE GFS WHICH HAD BEEN A TAD SLOWER THAN THE MULTI-MODEL CONSENSUS THOUGH IS NOW IN BETTER AGREEMENT WITH THE BROADER GLOBAL MODEL CONSENSUS...INCLUDING THAT OF THE ECMWF/GEM AND ALSO THE NAM. THE LATEST GEFS MEAN AND THE ECENS MEAN SUPPORTS A NON-UKMET CONSENSUS ATTM. ...SHORTWAVE DIGGING SOUTHEAST ACROSS THE MIDWEST AND OH/TN VALLEYS THIS WEEKEND... PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE MODELS CONTINUE TO ADVERTISE A SHORTWAVE IMPULSE DIGGING SEWD DOWN THE EAST SIDE OF A FLAT MEAN RIDGE OVER THE FOUR CORNERS AND HIGH PLAINS THIS WEEKEND...WITH THE MODELS SUPPORTING IT ADVANCING THROUGH THE MIDWEST ON SAT AND DOWN ACROSS ESP THE LWR OH VLY ON SUN AND THE TN VLY BY EARLY MON. WHILE SOME RELATIVELY MINOR DIFFERENCES EXIST AMONG THE GLOBAL MODELS...THERE IS RATHER GOOD AGREEMENT ON THE LARGER SCALE. WILL PREFER A GENERAL MODEL COMPROMISE. ...SHORTWAVE TROUGH/SURFACE LOW APPROACHING BRITISH COLUMBIA ON SAT... PREFERENCE: NON-NAM CONSENSUS CONFIDENCE: ABOVE AVERAGE WHILE THE NAM APPEARS GENERALLY WELL CLUSTERED WITH THE GLOBAL MODEL CONSENSUS ON SAT WITH THE TIMING AND STRENGTH OF THE SFC LOW APPROACHING BRITISH COLUMBIA...THE NAM IS A RELATIVELY DEEP OUTLIER ALOFT WITH THE SHORTWAVE ENERGY. WILL PREFER A NON-NAM CONSENSUS WITH THIS SYS. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ORRISON