MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 144 AM EST MON NOV 28 2016 VALID NOV 28/0000 UTC THRU DEC 01/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... ...AN EVALUATION OF THE 00Z MODELS ALONG WITH FINAL PREFERENCES/FORECAST CONFIDENCE... ...DEEP UPPER TROUGH INITIALLY OVER THE NORTHEAST US... ...SURFACE CYCLONE STRENGTHENING OVER THE CANADIAN MARITIMES MON... PREFERENCE: GENERAL MODEL BLEND FORECAST CONFIDENCE: ABOVE AVERAGE THE 00Z NAM AND GFS ARE CLOSE TO THE CONSENSUS WITH THE DEEPENING SURFACE LOW TRACKING TOWARD NEWFOUNDLAND AHEAD OF THE DEEPENING LONG WAVE TROUGH OVER NEW ENGLAND AND MARITIMES THROUGH MON. THERE WAS NO APPRECIABLE CHANGES IN THE SOLUTIONS OFFERED BY THE 00Z UKMET/CMC/ECMWF. ...SHORTWAVE TRACKING THROUGH THE DESERT SOUTHWEST... ...CLOSED LOW/STRONG CYCLOGENESIS OVER THE NORTHERN PLAINS/UPPER MS VALLEY MON THROUGH WED... PREFERENCE: NON-NAM MODEL BLEND FORECAST CONFIDENCE: ABOVE AVERAGE THE 00Z NAM WAS FURTHER NORTH WITH THE DEVELOPING SURFACE LOW OVER MN TUE...THEN FASTER WITH THE LOW OVER THE UPPER GREAT LAKES INTO ONTARIO/QUEBEC WED INTO EARLY THU. THE 00Z GFS WAS A BIT FASTER THAN THE CONSENSUS WITH THE SURFACE LOW TUE...BUT BECOMES VERY CLOSE TO THE 00Z ECMWF AND THE 00Z/12Z ENSEMBLE MEAN POSITIONS WITH RESPECT TO THE SURFACE LOW WED. ...SHORT WAVE TRACKING FROM THE RED RIVER VALLEY TO THE GREAT LAKES MON/TUE... PREFERENCE: GENERAL MODEL BLEND FORECAST CONFIDENCE: AVERAGE WHILE THERE WERE SOME TIMING DIFFERENCES WITH THE 00Z NAM/GFS WHEN COMPARED TO THE CONSENSUS AND ENSEMBLE MEAN POSITIONS WITH RESPECT TO THIS SHORT WAVE...THERE WAS GENERALLY GOOD AGREEMENT ACROSS ALL THREE DAYS...SO A GENERAL MODEL BLEND IS PREFERRED. ...SURFACE WAVE DEVELOPING ALONG THE NEW ENGLAND COAST TUE NIGHT/WED... PREFERENCE: BLEND OF THE 00Z GFS/00Z ECWMF... FORECAST CONFIDENCE: SLIGHTLY BELOW AVERAGE THE 00Z NAM CONTINUES TO BE FASTER WITH THE DEVELOPING ON THE SURFACE WAVE ON A FRONTAL BOUNDARY EXTENDING FROM THE ME COAST ACROSS THE GULF OF ME TO SOUTH OF NOVA SCOTIA. THE 00Z GFS CONTINUES TO BE A BIT SLOWER AND FURTHER SOUTH THAN THE 00Z ECMWF...AND EACH ENSEMBLE MEAN SUPPORTS ITS OPERATIONAL RUN. BOTH THE 00Z UKMET/CMC WERE SLOWER AND FURTHER SOUTH WITH THE WAVE DEVELOPMENT. AT THIS POINT...BLENDING THE 00Z GFS/00Z ECMWF SHOULD PRODUCE A REASONABLE PLACEMENT AND STRENGTH FOR THE WAVE THROUGH WED. ...SHORTWAVE IN THE MID LEVEL NORTHWEST FLOW OVER WA REACHING THE FOUR CORNERS TUE... PREFERENCE: 00Z ECMWF FORECAST CONFIDENCE: AVERAGE BOTH THE 00Z NAM/GFS WERE FASTER WITH THE SHORT WAVE AS IT CROSSED THE GREAT BASIN AND SOUTHERN ROCKIES THAN THE 00Z ECMWF/12Z ECMWF ENSEMBLE MEAN (AND THE 00Z GFS IS SUPPORTED IN ITS FASTER MOVEMENT BY THE 00Z GEFS MEAN). THE 00Z ECMWF HAS SHOWN BETTER RUN TO RUN CONSISTENCY WITH THE TIMING OF THE SHORT WAVE...SO ITS SOLUTION IS PREFERRED. ...LONG WAVE TROUGH AFFECTING VANCOUVER ISLAND WED... PREFERENCE: 00Z GFS/00Z ECMWF BLEND FORECAST CONFIDENCE: SLIGHTLY BELOW AVERAGE THE 00Z NAM CONTINUES TO BE FASTER WITH THE LONG WAVE TROUGH AS IT COMES ASHORE LATE MON...BUT IT CATCHES UP BY LATE WED. THE 00Z GFS IS SLOWER THAN THE CONSENSUS (AND THE SLOWER SOLUTION IS SUPPORTED BY THE 18Z GEFS MEAN TROUGH POSITION)...WHILE THE 00Z ECMWF/12Z ECMWF ENSEMBLE MEAN SOLUTIONS REMAIN A BIT FASTER. A BLEND OF THE 00Z GFS/00Z ECMWF SHOULD MITIGATE THE TIMING DIFFERENCES WITH THE POSITION OF THE MAIN TROUGH AXIS. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... HAYES