MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 140 AM EST FRI JAN 03 2014 VALID JAN 03/0000 UTC THRU JAN 06/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z MODEL EVALUATION INCLUDING FINAL PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. CYCLONE MOVING AWAY THE EAST COAST TODAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE MODELS SHOW VERY GOOD AGREEMENT WITH THIS SYSTEM AS IT MOVES AWAY FROM THE NORTHEAST COAST EARLY THIS MORNING. A GENERAL MODEL COMPROMISE IS PREFERRED WITH ANY SMALL SCALE DETAIL DIFFERENCES. NORTHERN STREAM SHORTWAVE TROUGH AND ATTENDANT SURFACE LOW / COLD FRONT CROSSING THE NORTH CENTRAL U.S. FRI NIGHT ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 00Z NAM / 00Z ECMWF COMPROMISE CONFIDENCE: AVERAGE A NRN STREAM SHORTWAVE IS EXPECTED TO TRACK THROUGH THE N-CNTRL U.S. FRI NIGHT WITH AN ACCOMPANYING SURFACE LOW AND COLD FRONT. THE GFS HAS BEEN CONSISTENTLY AHEAD OF THE REMAINING MODEL CONSENSUS FOLLOWED BY THE NAM WITH THE SHORTWAVE. MEANWHILE THE 00Z ECMWF/UKMET/CMC ARE SLOWER BUT THE ECMWF HAS ALSO BEEN CONSISTENT FROM RUN TO RUN. THE ENSEMBLE MEANS ARE A BIT QUICKER THAN THE ECMWF...INCLUDING THE 12Z EC MEAN WHICH HAS SHOWN A SUBTLE QUICKENING TREND OVER THE PAST 3 CYCLES. THE PREFERENCE IS FOR A 00Z NAM / 00Z ECMWF COMPROMISE WHICH MATCHES ENSEMBLE MEAN PLACEMENT THE BEST REGARDING THE MID-LEVEL SHORTWAVE AND 850 MB / SURFACE LOWS...WHEREAS THE 00Z UKMET/CMC ARE A LITTLE SOUTH WITH THEIR SURFACE LOWS RELATIVE TO THE PREFERENCE. SHORTWAVE DIVING INTO THE CENTRAL/SOUTHERN PLAINS SUN MORNING SURFACE LOW REACHING THE UPPER OHIO VALLEY SUN NIGHT ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 00Z ECMWF AND/OR 12Z EC MEAN CONFIDENCE: A LITTLE BELOW AVERAGE A MID-LEVEL SHORTWAVE IS FORECAST TO DROP INTO THE CNTRL/SRN PLAINS EARLY ON SUN...TO THE SOUTH OF AN ANOMALOUS CLOSED LOW OVER THE N-CNTRL U.S....WHICH SHOULD ALLOW A FRONTAL WAVE TO DEVELOP JUST WEST OF THE LOWER MISS VALLEY. THE NAM IS AN FLAT/FAST OUTLIER WITH THE SHORTWAVE ON SUN...WHILE THE 00Z GFS/CMC ARE NOTABLY FASTER THAN THE 00Z ECMWF/UKMET. THE CMC IS ALSO ON THE WEAKER SIDE OF THE SPREAD WITH THE SURFACE LOW AS IT TRACKS INTO THE NORTHEAST EARLY MON. ENSEMBLE SPAGHETTI LOW PLOTS SHOW THE 00Z ECMWF IS NOW CLUSTERED FAIRLY WELL WITHIN THE MIDDLE OF THE ECMWF/CMC MEMBERS WHILE THE GEFS MEMBERS ARE CLUSTERED WELL AHEAD OF THOSE FROM THE ECMWF/CMC ENSEMBLES. THIS IS SEEN AS AN IMPROVEMENT FROM THE 12Z ECMWF CYCLE. THE ECMWF HAS BEEN RATHER STEADY FROM RUN TO RUN...WITH THE GFS...CMC...UKMET DANCING AROUND THE ECWMF SOLUTION WITH EACH RUN. GIVEN THE SLIGHTLY FASTER/WEAKER TREND SEEN IN THE 00Z ECMWF...WILL INCLUDE IT AS THE PREFERENCE ALONG WITH THE 12Z EC MEAN. www.wpc.ncep.noaa.gov/html/model2.shtml... OTTO