MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 256 PM EDT MON JUL 25 2016 VALID JUL 25/1200 UTC THRU JUL 29/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION...INCLUDING FINAL PREFERENCES AND FORECAST CONFIDENCE ...UPPER LEVEL LOW CROSSING THE NORTHERN GULF OF MEXICO TUE/WED... PREFERENCE: NON-NAM BLEND CONFIDENCE: ABOVE AVERAGE THE 12Z NAM CONTINUES TO BE A BIT DEEPER AND FURTHER WEST WITH THE UPPER LOW AS IT REACHES THE TX COAST TUE INTO WED. THE 12Z GFS IS CLOSER TO THE CONSENSUS...AND IT BETTER SUPPORTED BY THE 00Z ECMWF ENSEMBLE MEAN/12Z GEFS. GIVEN THE GOOD MODEL AGREEMENT...A NON NAM BLEND IS PREFERRED. ...TROUGH OVER THE UPPER MIDWEST REACHING NEW ENGLAND TUE... PREFERENCE: GENERAL MODEL BLEND CONFIDENCE: SLIGHTLY ABOVE AVERAGE THE 12Z NAM AND 12Z GFS WERE CLOSE TO THE CONSENSUS WITH THE SHORT WAVE TRACKING ACROSS THE UPPER GREAT LAKES THROUGH QUEBEC INTO NEW ENGLAND TUE...AS WELL AS THE SURFACE FRONT IT PUSHES TO THE COAST. GIVEN THE GOOD MODEL AGREEMENT...A GENERAL MODEL BLEND IS PREFERRED. ...DEVELOPING MID LEVEL TROUGH OVER THE PLAINS INTO THE MIDWEST TUE INTO THU... PREFERENCE: 12Z GFS/12Z ECMWF BLEND CONFIDENCE: SLIGHTLY BELOW AVERAGE THE 12Z NAM IS CLOSE TO THE CONSENSUS WITH THE SHORT WAVE TRACKING OUT OF THE NORTHERN ROCKIES/NORTHERN PLAINS ON THE SOUTHERN EDGE OF THE WESTERLIES THAT DEVELOPS INTO A MID LEVEL TROUGH OVER THE MIDWEST/MID MS VALLEY. HOWEVER...THE 12Z NAM BECOMES FASTER THAN THE CONSENSUS BY THE END OF THE PERIOD. THE 12Z GFS IS ALSO CLOSE TO THE CONSENSUS THROUGH WED... BUT ENDS UP FASTER THAN THE 12Z ECMWF BY 29/00Z. THE FASTER 12Z GFS TIMING IS SUPPORTED BY THE 12Z GEFS MEAN POSITION (WHILE THE SLOWER 12Z ECMWF IS SUPPORTED BY THE 00Z ECMWF ENSEMBLE MEAN POSITION). GIVEN THE DIFFERENCES IN TIMING AT THE END OF THE PERIOD...BLENDING THE TWO CAMPS (12Z GFS/12Z ECMWF) SHOULD PROVIDE THE BEST SOLUTION...AND THIS BLEND IS PREFERRED. ...MID LEVEL TROUGH OVER THE PACIFIC NORTHWEST TUE INTO WED... PREFERENCE: NON-ECMWF CONSENSUS CONFIDENCE: AVERAGE THE 12Z NAM IS CLOSE TO THE CONSENSUS WITH THE TIMING OF THE MID LEVEL TROUGH ACROSS THE PACIFIC NORTHWEST/BRITISH COLUMBIA TUE INTO WED. THE 12Z GFS CONTINUES ITS DEEPER TREND WITH THIS FEATURE...BUT ITS TIMING WAS CLOSER TO THE CONSENSUS. THE 12Z ECMWF HAS BECOME THE FASTER OUTLIER WITH THIS TROUGH...MUCH FASTER THAN THE 12Z GFS/12Z UKMET/00Z ECMWF ENSEMBLE MEAN. BECAUSE OF THIS...THE 12Z ECMWF WAS REMOVED FROM THE PREFERENCE. HAYES www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml...