MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1106 PM EST SUN NOV 22 2015 VALID NOV 23/0000 UTC THRU NOV 26/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z MODEL EVALUATION...INCLUDING THE NAM AND GFS ...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-UKMET CONSENSUS...THROUGH 72 HOURS BLEND OF THE 00Z GFS AND 12Z ECMWF...AFTER 72 HOURS CONFIDENCE: ABOVE 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 UKMET TENDS TO A BIT MORE PROGRESSIVE AND GRADUALLY WEAKER THAN THE MULTI-MODEL CONSENSUS IN PIVOTING SOUTHWARD AND THEN EAST OUT INTO THE INTERMOUNTAIN REGION. THE 00Z NAM ALSO BECOMES A LITTLE DEEPER THAN THE SAME CONSENSUS OF GUIDANCE AFTER ABOUT 72 HOURS OVER THE INTERIOR. WILL PREFER A NON-UKMET CONSENSUS THROUGH 72 HOURS...FOLLOWED BY A 00Z GFS/12Z ECMWF BLEND THEREAFTER. ...UPPER TROUGH CROSSING SOUTHERN CANADA/NORTHERN PLAINS ON WED AND THURS... PREFERENCE: NON-CMC CONSENSUS CONFIDENCE: SLIGHTLY ABOVE 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 CMC TENDS TO BE A BIT DEEPER THAN THE MULTI-MODEL CONSENSUS INCLUDING THE 00Z NAM/00Z GFS/12Z UKMET AND 12Z ECMWF. THE 12Z CMC IS ALSO A BIT SLOWER AND AS A RESULT IT IS A BIT SLOWER THAN THE SAME MODEL CONSENSUS ACROSS THE NORTHERN PLAINS AND UPPER MS VALLEY BY THE END OF THE PERIOD. WILL FAVOR A NON-CMC CONSENSUS WITH THIS FOR THE TIME BEING. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ORRISON