MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1254 AM EST TUE MAR 07 2017 VALID MAR 07/0000 UTC THRU MAR 10/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z NAM/GFS EVALUATION WITH PRELIMINARY PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ DEEP CYCLONE MOVING EAST THROUGH THE OHIO VALLEY/ERN U.S. THROUGH WED ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL BLEND CONFIDENCE: AVERAGE TRENDS IN THE LATEST MODEL GUIDANCE HAVE SHOWN CONVERGENCE AND NOW THE MODELS SHOW SIMILARLY WITH THIS SYSTEM. ZONAL FLOW INTO THE PACIFIC NORTHWEST WITH EMBEDDED SUBTLE SHORTWAVE ON TUE/WED AND ASSOCIATED SURFACE LOW ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL BLEND UNTIL 08/12Z 00Z GFS/12Z ECMWF BLEND AFTER CONFIDENCE: AVERAGE THE MODELS HAVE CONVERGED WITH THE SURFACE LOW APPROACHING THE WASHINGTON COAST ON TUE/WED WITH A GENERAL MODEL BLEND RECOMMENDED. AFTERWARD...THE MODELS DIVERGE WITH MID-LEVEL HEIGHTS ACROSS THE WRN U.S./CANADIAN BORDER. TRENDS IN ENSEMBLE HEIGHTS CONTINUE TO SHOW CONVERGING BUT THE 12Z CMC REMAINS AN OUTLIER WITH HIGHER HEIGHTS ACROSS THE REGION. THE GFS/GEFS REMAIN TOWARD THE SRN SIDE OF THE MODEL SPREAD WITH THE 12Z ECWMF/UKMET IN THE MIDDLE. THE ENSEMBLE MEANS ARE FLATTER THAN THE 12Z UKMET/ECMWF WITH A BLEND OF THE 00Z GFS AND 12Z ECMWF APPROXIMATING CLOSE TO THE PREFERRED MIDDLE GROUND. POTENTIAL SURFACE CYCLONE REACHING THE PACIFIC NORTHWEST FRI MORNING ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 00Z GFS/12Z CMC BLEND CONFIDENCE: SLIGHTLY BELOW AVERAGE THERE HAS BEEN GROWING CONFIDENCE WITH THE PLACEMENT OF A SURFACE LOW EXPECTED TO APPROACH THE PACIFIC NORTHWEST FRI MORNING. THE LATEST ENSEMBLE SCATTER LOW PLOTS SHOW A GREAT DEAL OF SPREAD...BUT SOME CLUSTERING IS BEGINNING TO SHOW BETWEEN THE 00Z GFS AND 12Z CMC. RUN TO RUN CONTINUITY HAS BEEN DECENT IN THE GFS AND OTHER MODELS APPEAR TO BE JOINING...MOST NOTABLY THE 12Z CMC AND 00Z NAM. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... OTTO