MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 105 PM EDT MON JUL 14 2014 VALID JUL 14/1200 UTC THRU JUL 18/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z NAM/GFS EVALUATION WITH PRELIMINARY PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NAM/GFS INITIALIZATION ERRORS DO NOT APPEAR TO DEGRADE THEIR SHORT RANGE FORECASTS. COLD TROUGH/DEEP CYCLONE IN EASTERN NORTH AMERICA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GFS/00Z ECMWF COMPROMISE CONFIDENCE: AVERAGE THERE ARE STILL SOME DIFFERENCES WITH HOW QUICKLY THE MODELS LIFT THE LOW NORTH FROM THE GREAT LAKES INTO EASTERN QUE. ALTHOUGH THE 12Z GFS HAS SLOWED FROM ITS 00Z RUN...IT IS STILL FASTER THAN THE 00Z ECMWF. THE NAM HAS MADE AN EVEN MORE SIGNIFICANT DEPARTURE FROM ITS 00Z RUN AND IS NOW ONE OF SLOWER MODELS AND TAKES THE LOW FURTHER TO THE EAST AS WELL. THE UKMET AND CANADIAN GLOBAL HAVE REMAINED AMONG THE FASTER MODELS. WITH THE EXCEPTION OF THE CANADIAN--WHICH IS FASTER TO PUSH THE FRONT THROUGH THE NORTHEAST--DIFFERENCES OVER CANADA DO NOT SOME SEEM TO GREATLY IMPACT FEATURES OVER THE U.S. SHORTWAVE MOVING FROM THE NORTHWEST TO THE SOUTHERN PLAINS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE OVERALL...MODELS ARE IN FAIRLY GOOD AGREEMENT WITH THE TIMING/AMPLITUDE OF THIS FEATURE. SHORTWAVE MOVING INTO BRITISH COLUMBIA/PACIFIC NORTHWEST ON WED/THU ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-GFS COMPROMISE CONFIDENCE: AVERAGE THE GFS HAS MADE A SIGNIFICANT CHANGE FROM ITS 00Z RUN AND IS NOW MUCH LESS AMPLIFIED AND MORE PROGRESSIVE WITH THE ENERGY MOVING INTO WESTERN CANADA ON WED. THIS PUTS IT OUT OF PHASE WITH MAJORITY OF THE OTHER GUIDANCE www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... PEREIRA