MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 244 AM EDT SUN MAY 14 2017 VALID MAY 14/0000 UTC THRU MAY 17/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z MODEL EVALUATION WITH FINAL PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ...DEEP LOW TRACKING NORTHWARD NEAR THE NEW ENGLAND COAST THROUGH SUNDAY NIGHT... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL BLEND CONFIDENCE: ABOVE AVERAGE WHILE THE 12Z/13 AND 00Z/14 ECMWF TRACK NORTH OF THE REMAINING DETERMINISTIC CONSENSUS MONDAY NIGHT WITH THE DEEP LOW...THE SENSIBLE WEATHER IMPACTS AT THIS POINT IN TIME ARE MINIMAL. A GENERAL MODEL BLEND WILL SUFFICE FOR THIS SYSTEM WITH VERY GOOD AGREEMENT THROUGH MONDAY MORNING. ...CLOSED LOW LIFTING NORTH OVER BRITISH COLUMBIA TODAY... ...LONGWAVE TROUGH SHIFTING EAST TOWARDS THE WESTERN PLAINS WITH EMBEDDED NORTHERN STREAM SHORTWAVE ENERGY... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL BLEND CONFIDENCE: SLIGHTLY ABOVE AVERAGE NO SIGNIFICANT DIFFERENCES WERE NOTED WITH THIS SYSTEM. ...UPPER TROUGH OVER CA/NV BY MONDAY MORNING... ...MOVING TOWARDS THE SOUTHERN/CENTRAL PLAINS THROUGH TUESDAY... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 00Z GFS / 00Z ECMWF BLEND CONFIDENCE: AVERAGE THE BIGGEST DIFFERENCES WITH THIS SYSTEM ARE WITH THE TIMING OF THE SHORTWAVE AS IT BEGINS TO KICK OUT FROM THE SOUTHWEST CONUS. THE 00Z NAM IS THE FARTHEST SOUTH AND ON THE SLOWER SIDE OF THE DETERMINISTIC AND ENSEMBLE SPREAD. TRENDS IN THE ENSEMBLES HAVE SHOWN CONVERGENCE OVER THE PAST 4 CYCLES...BUT A MODEST AMOUNT OF SPREAD REMAINS. THE MIDDLE GROUND OF THE ENSEMBLES IS BETWEEN THE 00Z GFS AND 00Z ECMWF WITH THE 00Z GFS TRENDING SLOWER COMPARED TO ITS 12Z/13 CYCLE. IN FACT...THE 00Z UKMET/GFS/ECMWF/CMC SHOW REASONABLE AGREEMENT WITH THE TIMING OF THIS FEATURE WHICH HELPS CONFIDENCE. ...CLOSED LOW REACHING THE PACIFIC NORTHWEST TUE MORNING... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL BLEND CONFIDENCE: AVERAGE THERE ARE SOME SMALL TIMING DIFFERENCES BY TUE WITH THE 00Z GFS SLOWER AND 00Z ECMWF FASTER AS THE UPPER LOW DESCENDS ACROSS VANCOUVER ISLAND. THESE DIFFERENCES DIMINISH BY WED MORNING WITH ALL OF THE DETERMINISTIC MODELS SHOWING A SIMILAR STRENGTH AND TIMING OF THE UPPER LOW OVER THE INTERMOUNTAIN WEST. THE LATEST ENSEMBLE SPAGHETTI HEIGHTS ARE IN FAIR AGREEMENT WITH THE DETERMINISTIC CONSENSUS NEAR THE MIDDLE OF THE BETTER ENSEMBLE CLUSTERING. NO SIGNIFICANT CHANGES WERE MADE IN THE 00Z ECMWF/UKMET/CMC COMPARED TO THEIR PREVIOUS CYCLES OTHER THAN A SLIGHT SLOWING IN THE 00Z ECMWF. WWW.WPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML... /ALL LOWER CASE/ WWW.WPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML... /ALL LOWER CASE/ OTTO