MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 232 PM EDT TUE JUL 29 2014 VALID JUL 29/1200 UTC THRU AUG 02/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION WITH PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. NORTHERN CONTINENTAL DIVIDE ~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GFS/ECMWF/UKMET COMPROMISE CONFIDENCE: AVERAGE SHORTWAVE ENERGY MOVING UP THE CA COAST INTO THE NORTHERN CONTINENTAL DIVIDE IS HANDLED REASONABLY SIMILAR -- PARTICULARLY AT 700 HPA -- BY MUCH OF THE GUIDANCE, THOUGH THE CANADIAN IS STRONGER -- ITS USUAL BIAS. BETWEEN THIS SYSTEM AND A WEAK SHORTWAVE MOVING THROUGH WESTERN CANADA, THE 12Z NAM SPEEDS UP ITS SURFACE LOW PROGRESSION NEAR THE MT/ND/SASKATCHEWAN BORDER MORE THAN SEEN ON THE OTHER GUIDANCE. THE PREFERENCE IS FOR A COMPROMISE OF THE 12Z GFS/12Z ECMWF/12Z UKMET WITH AVERAGE CONFIDENCE CONSIDERING ITS APPARENTLY CONVECTIVE ORIGIN. LARGE UPPER TROUGH ACROSS THE PLAINS AND EAST ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE GUIDANCE IS IN VERY GOOD AGREEMENT IN THIS REGION. A GENERAL MODEL COMPROMISE SHOULD BE SUFFICE WITH ABOVE AVERAGE CONFIDENCE CONSIDERING THE GOOD AGREEMENT IN THE GUIDANCE. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ROTH