MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 144 PM EST MON NOV 23 2015 VALID NOV 23/1200 UTC THRU NOV 27/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION...INCLUDING FINAL MODEL PREFERENCES ...SURFACE LOW EXITING AWAY FROM NEW ENGLAND ON MON... PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE OVERALL THE ENSEMBLE SUITE AND OPERATIONAL DETERMINISTIC RUNS ARE WELL AGREED UPON WITH THE DETAILS OF EXITING LOW PRESSURE OFFSHORE NEW ENGLAND ON MON. A GENERAL MODEL COMPROMISE WILL BE PREFERRED. ...SHORTWAVE TROUGH/SURFACE LOW PRESSURE WEAKENING OVER THE GREAT LAKES MON... PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE STRONG DETERMINISTIC AND ENSEMBLE MODEL AGREEMENT EXISTS WITH POSITION/TRACK AND INTENSITY OF THE CLIPPER SYSTEM DROPPING SOUTHEAST TOWARD THE GREAT LAKES ON MON WHILE BEFORE THIS SYSTEM DAMPENS OUT. A GENERAL MODEL COMPROMISE WILL BE PREFERRED. ...PACIFIC CLOSED LOW MOVING ACROSS CALIFORNIA ON MON... ...ENERGY SHEARING OUT ACROSS THE GREAT BASIN AND HIGH PLAINS ON TUES... PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE GUIDANCE IS IN VERY GOOD AGREEMENT IN TAKING THE CURRENT COMPACT CLOSED LOW FEATURE OFF THE CA COAST INLAND ON MON AND THEN GRADUALLY SHEARING THE ENERGY OUT OVER THE NEXT COUPLE OF DAYS DOWNSTREAM OVER THE GREAT BASIN AND OUT INTO CENTRAL PLAINS ON TUES. WILL FAVOR AGAIN A GENERAL MODEL COMPROMISE. ...UPPER LOW DROPPING DOWN THROUGH THE PACIFIC NORTHWEST/GREAT BASIN... PREFERENCE: NON-GFS CONSENSUS CONFIDENCE: AVERAGE ALL OF THE MODELS SHOW EXCELLENT AGREEMENT IN DEVELOPING A RATHER STRONG MEAN LAYER RIDGE OVER THE GULF OF AK MON AND TUES WHICH WILL ALLOW SHORTWAVE ENERGY TO DIVE SOUTH-SOUTHEAST ACROSS FAR WESTERN CANADA AND THEN AMPLIFY INTO A SIGNIFICANT CLOSED LOW OVER THE WESTERN U.S. TUES AND WED. THE STRONG HEIGHT FALLS WILL BE ACCOMPANIED BY A POLAR FRONT THAT WILL SETTLE WELL SOUTH THROUGH THE NORTHWEST AND INTO THE INTERMOUNTAIN REGION WHILE ALSO SPREADING OUT ACROSS THE NORTHERN PLAINS. THE 12Z GFS START TO DIVERGE STARTING AT 72 HRS. 12Z GFS STALLS THE CLOSED LOW OVER THE GREAT BASIN BEFORE RETROGRADING. THIS RETROGRADE IS SOONER IN THE 12Z GFS THAN THE REST OF THE MODELS. THE NORTHERN STREAM ENERGY NEVER PHASES WITH THE NORTHERN STREAM TROUGH. THE REST OF THE MODEL GUIDANCE IS IN AGREEMENT THAT THE NORTHERN STREAM TROUGH PHASES WITH THE SOUTHERN STREAM CLOSED LOW AND TRANSFERS AT LEAST SOME ENERGY FROM THE NORTHERN STREAM INTO THE CLOSED LOW. THE 12Z CMC AND 12Z UKMET ARE ON BOARD WITH THE PHASING SOLUTION THAT IS DEPICTED IN THE 12Z NAM/ECMWF. THE 12 GFS BEING THE LONE OUTLIER...WILL PREFER A NON GFS SOLUTION. ...UPPER TROUGH CROSSING SOUTHERN CANADA/NORTHERN PLAINS ON WED AND THURS... PREFERENCE: NON-GFS CONSENSUS CONFIDENCE: AVERAGE THE MODELS SHOW REASONABLY GOOD AGREEMENT WITH A NORTHERN STREAM TROUGH CROSSING SOUTHERN CANADA AND THE NORTHERN PLAINS BY WED AND THURS. THE 12Z GFS IS THE MOST PROGRESSIVE WITH THE NORTHERN STREAM TROUGH. THE REST OF THE MODEL GUIDANCE PULLS SOME OF THIS SHORTWAVE ENERGY BACK INTO THE DEEP CLOSED LOW OVER THE SOUTHWEST WITH AT LEAST SOME PHASING WITH THE SOUTHERN STREAM. THE GFS NEVER PULLS ANY OF THIS ENERGY BACK INTO THE CLOSED LOW. PREFER A NON GFS SOLUTION AT THIS TIME. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... KREKELER