MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 256 PM EDT SAT NOV 05 2016 VALID NOV 05/1200 UTC THRU NOV 09/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION...INCLUDING FINAL PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ UPPER TROUGH CROSSING THE NORTHWEST EARLY SUN MORNING AND EJECTING EAST TOWARD THE GREAT LAKES BY TUE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: BLEND OF THE 12Z GFS/12Z UKMET CONFIDENCE: BELOW AVERAGE DETERMINISTIC/ENSEMBLE TRENDS HAVE SHOWN OPPOSING TRENDS OVER THE PAST 24 HOURS WITH SIGNIFICANT SPREAD REMAINING IN THE ENSEMBLES. THE DIFFERENCES ARISE FROM THE BASE OF THE UPPER TROUGH CURRENTLY ACROSS THE ERN PACIFIC...AND ITS AMPLITUDE AS IT CROSSES INTO THE NORTHWEST U.S. SUN MORNING. THE 00Z ECMWF/UKMET ARE ON THE DEEPER SIDE OF THE DETERMINISTIC/ENSEMBLE SPREAD DESPITE HAVING TRENDED NORTH WITH THE VORT MAX CONTAINED IN THE MID-LEVEL TROUGH AXIS ENDING SUN EVENING. THE 12Z GFS TRENDED TOWARD THE FLATTER SIDE OF THE ENSEMBLE SPAGHETTI HEIGHTS...AND THE 00Z/05 GFS APPEARED MORE REPRESENTATIVE OF THE RELATIVELY AGREEABLE ENSEMBLE MEANS. THE 12Z NAM WOULD BE CONSIDERED A SECOND OPTION THOUGH IT TOO ENDS UP TOWARD THE FLATTER/MORE PROGRESSIVE SIDE OF THE MODEL SPREAD AS THE UPPER TROUGH NEARS THE GREAT LAKES REGION. 19Z UPDATE: THE 12Z ECWMF TRENDED SIGNIFICANT WEAKER WITH THE SHORTWAVE...EVEN MORE THAN THE 12Z GFS. THE 12Z UKMET/CMC ALSO TRENDED FLATTER...BUT TO A MORE PREFERABLE AMPLITUDE...JUST A BIT STRONGER THAN THE 12Z GFS. GIVEN THE 12Z CMC IS A BIT FASTER...A BLEND OF THE STRONGER 12Z UKMET WITH FLATTER 12Z GFS IS RECOMMENDED. CONFIDENCE CONTINUES TO BE LOW GIVEN SIGNIFICANT RUN TO RUN CHANGES SEEN IN MUCH OF THE GUIDANCE. UPPER TROUGH AND COLD FRONT OFFSHORE THE PACIFIC NORTHWEST LATE MON ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON 12Z UKMET BLEND CONFIDENCE: ABOVE AVERAGE OUTSIDE OF THE SLOWER/MORE AMPLIFIED 12Z UKMET...ONLY MINOR TIMING/AMPLITUDE DIFFERENCES EXIST WITH THIS FEATURE AS IT NEARS THE WEST COAST LATE MON. THE ENSEMBLES SUPPORT THE AGREEABLE DETERMINISTIC CONSENSUS AS WELL. SHORTWAVE CURRENTLY OVER TX...WEAKENING OVER THE LOWER MS VALLEY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE MODELS SHOW SIMILARLY WITH THIS SYSTEM. CLOSED LOW OVER THE FOUR CORNERS THIS MORNING...WEAKENING INTO THE PLAINS THRU SUN ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON 12Z NAM COMPROMISE CONFIDENCE: SLIGHTLY ABOVE AVERAGE MOSTLY GOOD AGREEMENT HERE WITH THIS SYSTEM AS THE ENERGY LIFTS NORTHEAST OUT INTO THE CENTRAL/SOUTHERN PLAINS AND WEAKENS THROUGH SUN NIGHT. THE 12Z NAM IS JUST A LITTLE QUICKER THAN THE MODEL CONSENSUS. GIVEN THE GOOD MODEL AGREEMENT SEEN OTHERWISE...WILL FAVOR A NON-NAM CONSENSUS. BROAD CLOSED LOW OVER THE SRN PLAINS AND NRN MEXICO TUE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON 12Z CMC BLEND CONFIDENCE: AVERAGE THE 12Z CMC CONTINUES TO APPEAR A BIT MORE AGGRESSIVE IN INITIALLY DIGGING ENERGY SOUTHEASTWARD AND DEVELOPING A CLOSED LOW. WHILE THE REMAINING NON-CMC MODELS DIFFER SOME WITH PLACEMENT OF THE LOW...THEY ARE IN BROAD AGREEMENT. VARIED ENSEMBLE SPREAD KEEPS CONFIDENCE AVERAGE AT THIS TIME. UPPER TROUGH AMPLIFYING ACROSS NEW ENGLAND TONIGHT/SUN ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE MODELS SHOW SIMILARLY WITH THIS SYSTEM. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... OTTO