MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1237 PM EDT TUE MAY 06 2014 VALID MAY 06/1200 UTC THRU MAY 10/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z NAM/GFS EVALUATION WITH PRELIMINARY PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. UPPER TROUGH IN THE SOUTHWEST TODAY REACHING THE UPPER LAKES ON FRI ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 70% ECMWF / 30% GFS COMPROMISE CONFIDENCE: SLIGHTLY BELOW AVERAGE DESPITE SOME WOBBLING...THERE HAS BEEN AN OVERALL SLOWING TREND IN THE DETERMINISTIC/ENSEMBLE MODELS/MEMBERS...BUT THE 12Z NAM/GFS REMAIN QUICKER WITH THE TIMING OF THE SHORTWAVE TROUGH AXIS AS IT REACHING THE CNTRL PLAINS. MOST OF THE MODELS HAVE BEEN CONSISTENT...WHETHER CONSISTENTLY FAST OR CONSISTENTLY SLOW. THESE TIMING DIFFERENCES DIMINISH SOME AS THE SYSTEM REACHES THE GREAT LAKES. THE 00Z ECMWF APPEARS TO BE A DECENT MIDDLE GROUND SOLUTION GIVEN THE TRENDS...BUT WITH SOME WEIGHT GIVEN TO THE GFS GIVEN THEIR BETTER CLUSTERING TOWARD FRI. SLOWER TRENDS WARRANT MORE WEIGHT TOWARD THE SLOWER ECMWF. CLOSED MID-LEVEL LOW CURRENTLY OVER ALBERTA/SASKATCHEWAN TRAINING/WEAKENING COLD FRONT INTO THE N-CNTRL U.S. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: SLIGHTLY ABOVE AVERAGE THERE IS ENOUGH MODEL AGREEMENT IN PLACE THAT A GENERAL MODEL COMPROMISE CAN BE USED HERE. SYSTEM APPROACHING THE PACIFIC NORTHWEST THURSDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 00Z ECMWF/UKMET COMPROMISE CONFIDENCE: BELOW AVERAGE POOR MODEL AGREEMENT IN THE GULF OF ALASKA TRANSLATES TO POOR MODEL AGREEMENT ACROSS THE ERN PACIFIC WITH ABOVE AVERAGE SPREAD SEEN IN THE LATEST ENSEMBLE MEMBERS. GIVEN POOR RUN-TO-RUN CONTINUITY...THE PREFERENCE IS TO BE TOWARD THE MODE OF THE LATEST AND PREVIOUS MODEL SOLUTIONS WHICH IS CLOSE TO THE LATEST SREF/GEFS/EC MEANS. THE DETERMINISTIC MODELS CLOSEST TO THE MEANS ARE THE 00Z ECMWF/UKMET. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... OTTO