MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1225 PM EDT FRI MAY 29 2015 VALID MAY 29/1200 UTC THRU JUN 02/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z NAM/GFS EVALUATION AND PRELIMINARY PREFERENCES SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT OVER THE NORTHERN-CENTRAL PLAINS... PREFERENCE: EQUAL BLEND NAM OR GFS CONFIDENCE: ABOVE AVERAGE ALTHOUGH LARGE-SCALE WISE...MODEL AGREEMENT IS GOOD WITH THIS SYSTEM...ITS INTERACTION WITH THE MCV FARTHER SOUTH WARRANTS AN EMPHASIS UPON THE NAM AND GFS FOR GUIDANCE COMPARED TO THE 00Z ECMWF...WHICH POORLY DEPICTS THE MCV ALONG WITH ITS INTERACTION. SHORTWAVE TROUGH OVER THE MIDDLE-LOWER MS VALLEY... PREFERENCE: EQUAL BLEND NAM/GFS CONFIDENCE: ABOVE AVERAGE THE NAM AND GFS SHOW SEEMINGLY ACCURATE INITIALIZATION OF THIS SYSTEM COMPARED TO OLDER GUIDANCE INCLUDING A DEEPER SURFACE LOW AND STRONGER FRONT IN ADVANCE OF IT...THUS SUPPORTING AN INTERMEDIATE SOLUTION INVOLVING THE 2 SOLUTIONS. THE 00Z ECMWF SHOWS POOR ALIGNMENT WITH THE MCV AND THUS IS NOT RECOMMENDED. SHORTWAVE TROUGH OVER THE SOUTHERN ROCKIES... PREFERENCE: GFS CONFIDENCE: ABOVE AVERAGE THE NAM AND GFS ALLOW PORTIONS OF THE TROUGH TO SLOW DOWN AND POSSIBLY BREAK OFF FROM THE WESTERLIES ACROSS THE MIDDLE/LOWER MS VALLEY COMPARED TO THE 00Z ECMWF. GIVEN MORE RECENT INITIALIZATION AND TRENDS DEPICTING A LARGER AND MORE CONSOLIDATED REMNANT CIRCULATION...THEIR SLOWER SOLUTIONS SEEM MORE REASONABLE THAN THE FASTER AND WEAKER SOLUTIONS. HOWEVER...THE NAM IS NEARLY AN OUTLIER BY LATE MONDAY...WITH THE GFS BETTER SUPPORTED BY THE ENSEMBLE MEMBERS. THUS...RECOMMEND THE GFS. SHORTWAVE TROUGH REACHING THE PACIFIC NORTHWEST SUN-MON... PREFERENCE: NAM OR GFS OR ECMWF CONFIDENCE: AVERAGE MODELS SHOW GOOD LARGE SCALE AGREEMENT WITH AVERAGE SPREAD BY DAY 3. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... JAMES