MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1116 PM EST MON FEB 09 2015 VALID FEB 10/0000 UTC THRU FEB 13/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z NAM/GFS EVALUATION INCLUDING PRELIMINARY MODEL PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ GFS/NAM INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. TROUGH AMPLIFYING OVER THE EAST WEDNESDAY/THURSDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GFS/ECMWF/CANADIAN COMPROMISE CONFIDENCE: SLIGHTLY ABOVE AVERAGE THE 00Z NAM/21Z SREF MEAN/12Z UKMET ARE SLOWER/SHARPER WITH THIS SYSTEM MOVING FROM THE GREAT LAKES INTO THE NORTHEAST -- BOTH THE NAM/SREF MEAN CAN HAVE A SLOW BIAS WITH SYSTEMS MORE THAN TWO DAYS INTO THE FUTURE AND THE UKMET CAN BECOME TOO AMPLIFIED. THE BROADER FLOW PATTERN FEATURES A BROADENING RIDGE UPSTREAM NEAR THE WEST COAST, WHICH WOULD FAVOR A BROADER DOWNSTREAM TROUGH (ELIMINATING THE UKMET FROM CONSIDERATION). THE 18Z GEFS MEAN SHOWS A COMPROMISE PROGRESSION WHILE THE 00Z GFS/12Z ECMWF/12Z CANADIAN SHOW GREATER PROGRESSION AND A POTENTIAL CLOSED 500 HPA CYCLONE EARLY FRIDAY. TO DEAL WITH THE GFS'S STRONGER SOLUTION, PREFER A COMPROMISE OF THE CANADIAN/ECMWF/GFS GUIDANCE WITH SLIGHTLY ABOVE AVERAGE CONFIDENCE. SYSTEM MOVING INTO SOUTH-CENTRAL CANADA EARLY FRI ENERGY DROPPING THROUGH THE SOUTHWEST WED/THU SYSTEM LEAVING THE EAST COAST TUESDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE GUIDANCE IS IN GOOD AGREEMENT WITH THESE SYSTEMS, SO PREFER A COMPROMISE OF THE EXISTING CONSENSUS TO DEAL WITH ANY LINGERING DETAIL ISSUES. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ROTH