MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1247 AM EDT SUN JUL 03 2016 VALID JUL 03/0000 UTC THRU JUL 06/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z NAM/GFS EVALUATION WITH PRELIMINARY PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. UPPER LEVEL TROUGHING OVER THE NORTHWEST THROUGH WED MORNING ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON 00Z GFS COMPROMISE CONFIDENCE: SLIGHTLY ABOVE AVERAGE THE GFS DISTANCES ITSELF FROM THE REMAINING GOOD MODEL CLUSTERING IN SWRN CANADA BY HANGING BACK MID-LEVEL TROUGHING TUE-WED. LACK OF SUPPORT FOR THE GFS PRECLUDES IT BEING PREFERRED. SURFACE LOW AND COLD FRONT TRACK THROUGH SRN CANADA MON/TUE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 00Z NAM / 12Z ECMWF BLEND CONFIDENCE: AVERAGE THE 00Z GFS APPEARS TOO STRONG WITH THE SURFACE LOW TRACKING MON NIGHT INTO TUE MID-UPPER LEVEL SHORTWAVE TRACKING FROM CALIFORNIA SUN MORNING TO THE CNTRL/SRN PLAINS TUE MORNING ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: AVERAGE THE MODELS SHOW SIMILARLY WITH THIS SYSTEM...ALTHOUGH THE 00Z ECMWF IS ON THE NRN SIDE WITH RESPECT TO THE DETERMINISTIC GUIDANCE. SHORTWAVE TRACKING INTO MISSOURI SUNDAY...REACHING THE EAST COAST TUE AFTERNOON ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 00Z GFS...12Z ECMWF...12Z UKMET COMPROMISE CONFIDENCE: SLIGHTLY ABOVE AVERAGE TRENDS HAVE BEEN NORTH OVER THE PAST 24 HRS BUT THE 12Z CANADIAN AND 00Z NAM ARE STRONGER ALOFT WITH THIS SYSTEM...LIKELY TOO STRONG. THE 00Z GFS AND 12Z ECMWF HAVE SIMILAR STRENGTH BUT THE 12Z ECMWF IS A BIT FASTER THAN THE GFS AS THE SYSTEM TRACKS TOWARD THE EAST COAST. BY TUE MORNING...THE 12Z ECMWF APPEARS TO DEVELOP A SURFACE LOW TOO FAR EAST INTO THE ATLANTIC GIVEN ITS LOCATION ON THE ERN EDGE OF THE ENSEMBLE SPREAD...BUT IMPACTS TO THE NORTHEAST BEGIN TO SHIFT OFFSHORE BY THIS POINT. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... OTTO