MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1229 AM EDT MON OCT 13 2014 VALID OCT 13/0000 UTC THRU OCT 16/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z NAM/GFS EVALUATION...INCLUDING PRELIMINARY PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ DEEP TROUGH AND ASSOCIATED CLOSED LOW MOVING INTO THE CENTRAL AND EASTERN U.S. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: BLEND OF THE 00Z NAM AND 12Z ECMWF CONFIDENCE: AVERAGE 564 DM ENSEMBLE SPAGHETTI HEIGHTS AT 500 MB FROM THE ECMWF/GEFS/CMC HAVE CONTINUED TO SHOW CONVERGENCE TOWARD THE MIDDLE OF THE MODEL SPREAD SINCE YESTERDAY. THERE HAS ALSO BEEN CONVERGENCE IN THE DETERMINISTIC RUNS...BUT THE ECMWF REMAINS CONSISTENTLY SLOWER THAN THE CONSISTENTLY QUICKER GFS. HOWEVER...THE 12Z ECMWF IS THE SLOWEST OF THE DETERMINISTIC MODELS AND COULD BE A BIT TOO SLOW...AS IT IS ALSO A BIT SLOWER THAN THE 12Z EC MEAN. BY 12Z/16...THE 12Z UKMET COULD BE A BIT TOO QUICK LIKE THE 00Z GFS...BUT THE 00Z NAM APPEARS TO BE A FAVORABLE POSITION IN THE MIDDLE OF THE SPREAD. MINOR BUT STEADY SLOWING TRENDS IN THE EC MEAN SUGGEST TO KEEP THE ECMWF IN THE BLEND...SO A 00Z NAM / 12Z ECMWF BLEND WILL BE PREFERRED. DEEP TROUGH IMPACTING THE NORTHWEST...WITH SHORTWAVE EJECTING OUT TO THE NRN PLAINS BY THU MORNING ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: BLEND OF THE 00Z GFS AND 12Z ECMWF CONFIDENCE: SLIGHTLY ABOVE AVERAGE THE MODELS SHOW GOOD AGREEMENT UNTIL ABOUT 00Z/16 WHEN SOME TIMING DIFFERENCES BEGIN TO APPEAR WITH AN EMBEDDED SHORTWAVE TROUGH...FORECAST TO REACH THE NRN PLAINS BY 12Z/16...THU MORNING. THE ECMWF/UKMET HAVE HELD THE BEST CONTINUITY WITH THE 12Z ECMWF ABOUT 200 MILES NORTH OF THE 12Z UKMET CONCERNING THE APPROXIMATE CENTER OF THE SHORTWAVE TROUGH. THE 00Z GFS AGREES WITH THE 12Z UKMET AND 00Z CMC AGREES WITH THE 12Z ECMWF WHILE THE NAM SHOWS SOME DIFFERENCES FROM THE PACK ALOFT. THEREFORE A SIMPLE GFS/ECMWF BLEND WILL BE PREFERRED AT THIS TIME. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... OTTO