MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1224 PM EDT TUE AUG 09 2016 VALID AUG 09/1200 UTC THRU AUG 13/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION...INCLUDING THE NAM AND GFS ...PERSISTENT LOW-MID LEVEL LOW ACROSS THE NORTHERN GULF OF MEXICO... ...ENERGY IMPACTING THE GULF COAST STATES PREFERENCE: BLEND OF THE 12Z NAM/12Z GFS AND 00Z ECMWF CONFIDENCE: AVERAGE THE MODELS ALL AGREE IN TAKING THE LOW TO MID LEVEL LOW CENTER OVER THE NORTHEAST GULF OF MEXICO GRADUALLY WEST-NORTHWEST OVER THE NEXT COUPLE OF DAYS WITH DIRECT IMPACTS TO THE GULF COAST STATES IN TERMS OF HEAVY RAINFALL. THE 00Z CMC GRADUALLY BECOMES THE SLOWEST SOLUTION...AND THE 00Z UKMET THE STRONGEST. THE ENSEMBLE MEANS LED BY THE 06Z GEFS MEAN AND 00Z ECENS MEAN ARE A LITTLE MORE PROGRESSIVE AND WEAKER BY COMPARISON...AND SUPPORT THE DETERMINISTIC 12Z NAM/12Z GFS AND 00Z ECMWF WHICH ARE RATHER WELL CLUSTERED. A BLEND OF THE LATTER CAMP WILL BE PREFERRED AT THIS POINT. PLEASE CONSULT THE LATEST QPFPFD FOR MORE INFORMATION ON THE HEAVY RAINFALL THREAT. ...SHORTWAVE TRACKING ACROSS SOUTHERN CANADA TODAY... ...COLD FRONT MOVING THROUGH THE GREAT LAKES/NEW ENGLAND THROUGH THURS... PREFERENCE: NON-NAM CONSENSUS CONFIDENCE: SLIGHTLY ABOVE AVERAGE THE 12Z NAM IS A TAD STRONGER WITH THE SHORTWAVE VERSUS THE OTHERWISE WELL CLUSTERED GLOBAL MODELS. WILL PREFER A NON-NAM CONSENSUS AT THIS POINT. ...CLOSED LOW OVER THE PACIFIC NORTHWEST... ...POSITIVE TILT TROUGH EJECTING ACROSS THE WEST AND INTO THE PLAINS... ...SURFACE LOW IMPACTING THE NORTHERN PLAINS/MIDWEST... PREFERENCE: BLEND OF THE 12Z GFS AND 00Z ECMWF CONFIDENCE: AVERAGE THE 12Z NAM OVERALL MAY BE A TAD TOO STRONG WITH THE EJECTING CLOSED LOW AND HEIGHT FALLS THAT OVERSPREAD THE NORTHERN PLAINS AND UPPER MIDWEST THROUGH THE PERIOD. THE 12Z NAM ALSO IS LIKELY TOO PROGRESSIVE AND TOO STRONG WITH ITS SURFACE LOW CENTER WHICH BY THE END OF THE PERIOD IT HAS EXITING THE GREAT LAKES REGION AND MOVING INTO THE ST LAWRENCE RIVER VALLEY. THE 00Z CMC IS LIKELY TOO WEAK WITH ITS HEIGHT FALLS AND ALSO TENDS TO HAVE A MORE PROGRESSIVE LOW CENTER COMPARED TO THE MODEL CONSENSUS. STRONGER MODEL CLUSTERING AND ENSEMBLE SUPPORT RESIDES WITH THE 12Z GFS AND 00Z ECMWF...AND SO A BLEND OF THESE SOLUTIONS WILL BE PREFERRED. REGARDING THE POSITIVELY TILTED TROUGH EXTENDING INTO THE SOUTHWEST U.S. THROUGH THE END OF THE WEEK...THE MODELS ARE GENERALLY WELL CLUSTERED WITH THEIR TIMING AND DEPTH. ORRISON www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml...