MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1232 PM EDT WED AUG 06 2014 VALID AUG 06/1200 UTC THRU AUG 10/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION...INCLUDING THE NAM AND GFS ...UPPER TROUGH ACROSS THE GREAT LAKES/NORTHEAST THROUGH THURS... PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE MODELS ARE IN EXCELLENT AGREEMENT ON THE DETAILS OF THE SLOWLY EXITING UPR TROUGH OVER THE GREAT LAKES AND NORTHEAST. WILL PREFER A GENERAL MODEL COMPROMISE. ...UPPER TROUGH OVER THE GREAT BASIN... PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE MOST OF THE OPERATIONAL MODELS ARE CONSISTENT IN SUGGESTING A FAIRLY WELL-DEFINED TROUGH AXIS THAT SHOULD MOVE ACROSS THE GRT BASIN AND INTO UT/WY BY THURS AND FRI...BEFORE THEN EXITING EWD OUT ACROSS THE N CNTRL PLAINS SAT. MEANWHILE...A SEPARATE PIECE OF THIS ENERGY WHICH IS CURRENT OVER NRN CA SHOULD DROP SWD INTO SRN CA THROUGH THURS. GIVEN A LACK OF LARGE SCALE MODEL DISAGREEMENT...WILL PREFER A GENERAL MODEL COMPROMISE TO RESOLVE THE SMALLER SCALE DETAILS. ...MID LEVEL SHORTWAVE TROUGH IMPACTING THE NORTHERN U.S. THROUGH THURS AND FRI... PREFERENCE: NON-UKMET CONSENSUS CONFIDENCE: AVERAGE ALL OF THE MODELS SHOW A MID LVL SHORTWAVE TROUGH THAT WILL TRAVERSE THE NRN TIER STATES INCLUDING THE GREAT LAKES REGION THROUGH THURS AND FRI. THE 12Z NAM AND 12Z GFS ARE IN REASONABLY GOOD AGREEMENT WITH THE 00Z ECMWF AND 00Z GEM SOLNS. THE 00Z UKMET HOWEVER IS STRONGER AND ALSO FASTER WITH THE EVOLUTION OF THE ENERGY. THE LATEST GEFS MEAN AND ECENS MEAN FAVOR A CONSENSUS AWAY FROM THE UKMET. SO...A NON-UKMET CONSENSUS WILL BE PREFERRED ATTM. ...MID LEVEL SHORTWAVE TROUGH DIGGING INTO THE NORTHWEST THURS AND FRI... PREFERENCE: NON-UKMET CONSENSUS CONFIDENCE: AVERAGE THE 12Z UKMET EVENTUALLY BECOMES A BIT MORE PROGRESSIVE WITH THE INITIAL SHORTWAVE TROUGH THAT DIGS INTO THE NORTHWEST THURS AND FRI. THE 12Z NAM AND 12Z GFS ARE IN STRONG AGREEMENT WITH THE 00Z ECMWF AND 00Z GEM WHICH ARE A LITTLE SLOWER. WILL PREFER A NON-UKMET CONSENSUS. ...MID LEVEL SHORTWAVE ATTEMPTING TO CLOSE OFF OVER NORTHERN CA ON SAT... PREFERENCE: BLEND OF THE 06Z GEFS MEAN/00Z ECENS MEAN CONFIDENCE: BELOW AVERAGE THE 00Z UKMET IS A RELATIVELY STRONGER OUTLIER WITH THE SHORTWAVE ENERGY DIGGING SEWD AND AMPLIFYING INTO NRN CA ON SAT. THE 00Z ECMWF OVERALL IS THE WEAKEST...WITH THE 12Z GFS/12Z NAM AND 00Z GEM GENERALLY SPLITTING THE DIFF...ALTHOUGH THE 00Z GEM BECOMES MORE ROBUST LIKE THE 00Z UKMET BY THE END OF THE PERIOD IN SUGGESTING A CLOSED LOW NEAR OR JUST NORTH OF NRN CA. THE 12Z NAM AND 12Z GFS WOULD FAVOR ANY CLOSED LOW FARTHER NORTH NEAR THE PAC NORTHWEST. THE LATEST GEFS MEAN AND ECENS MEAN ARE BOTH CLUSTERED VERY WELL TWD A SOLN THAT IS A LITTLE WEAKER...BUT THEY LIKE THE IDEA OF A BROAD TROUGH AND WEAK CLOSED LOW INVOF OR/NRN CA. GIVEN THE OVERALL MODEL SPREAD REGARDING DEPTH AND POSITION OF ANY CLOSED LOW BY THE END OF THE PERIOD...WILL FAVOR AN ENSEMBLE MEAN APPROACH. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ORRISON