MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 247 PM EDT WED OCT 29 2014 VALID OCT 29/1200 UTC THRU NOV 02/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION WITH MODEL PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. AMPLIFIED TROUGH APPROACHING WESTERN NORTH AMERICA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GFS/ECMWF COMPROMISE CONFIDENCE: ABOVE AVERAGE THE 12Z GLOBAL MODELS SHOWED SOME MINOR DIFFERENCE IN THE DETAILS FROM RUN TO RUN...ALTHOUGH NONE OF THEM DEVIATED FROM THEIR PREVIOUS SOLNS BY MUCH. THIS LEAVES THE 12Z NAM ON THE SLOW SIDE OF THE GUIDANCE WHILE THE NEW UKMET WAS SOMEWHAT FASTER THAN PREVIOUS RUNS. THE 12Z GFS/ECMWF STILL LIE IN THE MIDDLE OF THE GUIDANCE SPREAD AND ARE CLOSE TO THE GEFS ENSEMBLE MEANS FROM OVERNIGHT. TROUGH AMPLIFYING ACROSS EASTERN NORTH AMERICA CLOSED LOW POTENTIALLY DROPPING INTO THE CAROLINAS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: ECMWF/GFS COMPROMISE CONFIDENCE: BELOW AVERAGE THIS TROUGH AMPLIFIES DUE TO UPSTREAM AMPLIFICATION OF A TROUGH/RIDGE COUPLET NEAR THE WEST COAST/GREAT PLAINS RESPECTIVELY. THE MODELS STILL MAINTAIN BETTER CONVERGENCE THAT APPEARED IN THE 29/00Z GUIDANCE. THE 12Z NAM REMAINED DEEPER AND ON THE SOUTHWEST SIDE OF THE GUIDANCE BY SATURDAY MORNING -- ITS USUAL BIAS. THE 29/00Z AND 29/12Z UKMET AND THE OVERNIGHT GEFS FORMED A FAIRLY STRONG ALLIANCE. SO STILL THINK A COMPROMISE BETWEEN THE NEW ECMWF/GFS HAD THE BEST SUPPORT. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... BANN