MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 118 AM EDT FRI OCT 14 2016 VALID OCT 14/0000 UTC THRU OCT 17/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z NAM/GFS EVALUATION WITH PRELIMINARY PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. LOW OFFSHORE THE NORTHWEST SUNDAY NIGHT ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON 12Z CMC COMPROMISE CONFIDENCE: ABOVE AVERAGE THE 12Z CMC DIFFERS FROM THE REMAINING GUIDANCE IN SHOWING A MORE SOUTHERN CYCLONE HEADING FOR OREGON SUNDAY NIGHT AND A STRONGER LOW OFFSHORE BRITISH COLUMBIA. GIVEN THE BETTER ENSEMBLE SUPPORT FOR A NON CMC POSITION...A NON 12Z CMC COMPROMISE IS PREFERRED. AS THE UPPER TROUGH MOVES INTO THE INTERIOR WEST FOR MON...MINOR AMPLITUDE DIFFERENCES EXIST AMONG THE NON 12Z CMC MODELS...BUT THESE DIFFERENCES ARE SMALL ENOUGH TO BE BLENDED TOGETHER. POST-TROPICAL CYCLONE SONGDA MOVING BY PACIFIC NW SAT ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 00Z GFS / 12Z ECMWF COMPROMISE CONFIDENCE: AVERAGE THE GUIDANCE IS IN MUCH BETTER AGREEMENT WITH THIS SYSTEM COMPARED TO YESTERDAY. THERE ARE SOME STRENGTH/PLACEMENT DIFFERENCES...BUT THE 12Z CMC STANDS OUT TO BE QUICKER WITH THE SURFACE LOW INTO WASHINGTON SAT EVENING. THE 12Z UKMET REMAINS THE STRONGEST WITH THE LOW CENTRAL PRESSURE...BUT IT IS UNSUPPORTED AT THIS TIME. WHILE THE 00Z GFS HAS TRENDED WEAKER...ITS POSITION IS FAVORABLE AND WHEN BLENDED WITH THE 12Z ECMWF...A DECENT COMPROMISE CLOSEST TO THE BEST ENSEMBLE POSITION/STRENGTH IS REACHED. POWERFUL UPPER TROUGH CROSSING THE PACIFIC NORTHWEST THIS MORNING AND RELATED COLD FRONT MOVING ACROSS THE NRN TIER THIS WEEKEND ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: AVERAGE THE MODELS SHOW SIMILARLY WITH THIS SYSTEM. SHORTWAVE TROUGH TRACKING ACROSS THE LOWER MISSISSIPPI VALLEY TODAY AND INTO THE SOUTHEAST SATURDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 12Z UKMET / 12Z ECMWF COMPROMISE CONFIDENCE: BELOW AVERAGE THERE HAVE BEEN SLOWING TRENDS IN THE GFS TO BE NEAR THE 12Z ECMWF BY MON MORNING REGARDING THE UPPER LOW NEAR FLORIDA...BUT ENSEMBLE SPREAD IS TOO GREAT TO HAVE MUCH CONFIDENCE HERE. A BLEND OF THE 12Z ECMWF/UKMET IS CLOSEST TO THE MIDDLE OF THE LATEST DETERMINISTIC SPREAD. CONFIDENCE IS BELOW AVERAGE GIVEN THE MANY POSSIBLE MODEL SOLUTIONS SHOWN. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... OTTO