MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1200 AM EDT MON JUL 25 2016 VALID JUL 25/0000 UTC THRU JUL 28/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z MODEL EVALUATION...INCLUDING THE NAM AND GFS ...WEAK UPPER LEVEL LOW CROSSING THE NORTHERN GULF OF MEXICO... PREFERENCE: NON-NAM CONSENSUS CONFIDENCE: SLIGHTLY ABOVE AVERAGE A WEAK UPPER LOW CROSSING THE FLORIDA PENINSULA WILL CONTINUE TRACKING WESTWARD THROUGH TUES...TRAVERSING THE GULF OF MEXICO BEFORE REACHING THE TX COAST BY TUES NIGHT. THE 00Z NAM CONTINUES TO BE A TAD DEEPER THAN THE MODEL CONSENSUS...SO WILL AGAIN PREFER A NON-NAM COMPROMISE. ...TROUGH OVER THE UPPER MIDWEST REACHING NEW ENGLAND TUES MORNING... PREFERENCE: NON-NAM CONSENSUS CONFIDENCE: SLIGHTLY ABOVE AVERAGE A PROGRESSIVE MID LEVEL TROUGH WILL TRACK ACROSS THE UPPER GREAT LAKES THROUGH MON MORNING AND THEN REACHING QUEBEC CANADA ON TUES. THIS WILL RESULT IN A SURFACE COLD FRONT ADVANCING ACROSS THE GREAT LAKES AND NORTHEAST STATES. THE 00Z NAM REMAINS SLIGHTLY MORE AMPLIFIED THAN THE WELL-CLUSTERED GLOBAL MODELS. WILL PREFER A NON-NAM CONSENSUS WITH THIS SYSTEM. ...LOW-AMPLITUDE SHORTWAVES CROSSING THE NORTHERN PLAINS/MIDWEST THROUGH MIDWEEK... ...BROAD TROUGH AMPLIFICATION OVER THE PLAINS THROUGH MIDWEEK... ...WEAK SURFACE WAVE DEVELOPMENT OVER THE MIDWEST... PREFERENCE: BLEND OF THE 00Z GFS AND 12Z ECMWF CONFIDENCE: SLIGHTLY BELOW AVERAGE THE GUIDANCE SHOWS A SERIES OF GENERALLY LOW-AMPLITUDE SHORTWAVES EMBEDDED WITHIN THE WESTERLIES NORTH OF THE SUBTROPICAL RIDGE...CROSSING THE MIDWEST TUES AND WED. THIS GRADUALLY LEADS TO SOME BROADER SCALE TROUGH AMPLIFICATION OVER THE PLAINS BY THURS. OVERALL...THE 00Z NAM IS MORE AMPLIFIED WITH THE SHORTWAVE DETAILS OVER THE REGION. BY THE END OF THE PERIOD...THE 12Z CMC APPEARS TO BE TOO DEEP WITH ITS TROUGH OVER THE PLAINS. THE 12Z UKMET ON THE FLIP SIDE LOOKS TO BE TOO WEAK. THE 00Z GFS AND 12Z ECMWF HAVE BETTER AGREEMENT ON THE LARGER SCALE...BUT THEIR ARE SOME TIMING DIFFERENCES NOTED WITH THE SHORTWAVE IMPULSES...WITH THE 00Z GFS MORE PROGRESSIVE AND THE 12Z ECMWF SLOWER. THE GEFS MEAN AND ECENS MEAN SUPPORT THEIR RESPECTIVE DETERMINISTIC SOLUTIONS...AND SO WILL SUGGEST A COMPROMISE BETWEEN THE GFS AND ECMWF AT THIS POINT. ...TROUGH OVER THE PACIFIC NORTHWEST... PREFERENCE: NON-GFS CONSENSUS CONFIDENCE: AVERAGE THE MODELS HAVE A SHORTWAVE TROUGH GRADUALLY CROSSING THE NORTHWEST TUES AND WED. SOME RELATIVELY MINOR DIFFERENCES WITH TIMING/DEPTH EXIST WITH THIS SYSTEM...ALTHOUGH THE 00Z GFS DOES GENERALLY SUGGEST A MORE AMPLIFIED SYSTEM THAN THE MODEL CONSENSUS. WILL PREFER A NON-GFS COMPROMISE AS A RESULT FOR THE TIME BEING. ORRISON www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml...