MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1221 PM EDT TUE JUN 09 2015 VALID JUN 09/1200 UTC THRU JUN 13/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z NAM/GFS EVALUATION WITH PRELIMINARY MODEL PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. SYSTEM MOVING ACROSS SOUTHWEST CANADA FRIDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GFS/NAM/ECMWF COMPROMISE CONFIDENCE: ABOVE AVERAGE THE 00Z CANADIAN WAS FARTHER SOUTHEAST WITH ITS CLOSED LOW AT 500 HPA WHICH LED TO A MUCH DIFFERENT SURFACE LOW PLACEMENT ACROSS ALBERTA AND SASKATCHEWAN. THE 00Z UKMET WAS THE QUICKEST -- ITS USUAL BIAS. A COMPROMISE OF THE 12Z GFS/12Z NAM/00Z ECMWF LOOKS BEST HERE, WHICH IS PREFERRED WITH ABOVE AVERAGE CONFIDENCE. SYSTEM MOVING ACROSS THE UPPER MIDWEST FRIDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-UKMET COMPROMISE CONFIDENCE: AVERAGE THE 00Z UKMET WAS STRONG AND QUICK -- ITS USUAL BIAS -- WITH A SYSTEM NEAR THE GREAT LAKES FRIDAY WHEN COMPARED TO THE REMAINDER OF THE DETERMINISTIC AND 00Z ENSEMBLE LOW GUIDANCE. A COMPROMISE OF THE 12Z GFS/12Z NAM/00Z CANADIAN/00Z ECMWF LOOKS BEST HERE AND STAYS WITHIN THE RANGE OF THE ABOVE AVERAGE ENSEMBLE LOW SPREAD. CONFIDENCE IN THIS CHOICE IS AVERAGE. TROUGH MOVING THROUGH THE SOUTHWEST WED-FRI SYSTEM MOVING THROUGH NEW ENGLAND THURSDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE GUIDANCE SHOWS GOOD AGREEMENT WITH THESE SYSTEMS. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ROTH