MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1252 PM EDT WED MAY 11 2016 VALID MAY 11/1200 UTC THRU MAY 15/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... ...NOTE: THE GFS WAS UPGRADED AS OF THE 12Z MODEL RUN TODAY. REFER TO TECHNICAL IMPLEMENTATION NOTE TIN16-11 AT WWW.NWS.NOAA.GOV/OM/NOTIF.HTM FOR FURTHER DETAILS... 12Z MODEL EVALUATION WITH PREFERENCES/CONFIDENCE INTERVALS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ GFS/NAM INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. SYSTEM MOVING THROUGH BRITISH COLUMBIA INTO THE NE PACIFIC DEEP CYCLONE ROTATING AROUND NEWFOUNDLAND TROUGHING LIFTING OUT OF NEW ENGLAND SHORTWAVE CROSSING THE NORTHERN MID-ATLANTIC THURSDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ THE GUIDANCE SHOWS GOOD AGREEMENT WITH THESE SYSTEMS, SO A GENERAL MODEL COMPROMISE WILL DEAL WITH LINGERING DETAIL ISSUES EFFECTIVELY WITH ABOVE AVERAGE CONFIDENCE. DEEP CYCLONE MOVING TOWARDS NORTHERN CA FRIDAY NIGHT ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 11/00Z ECMWF CONFIDENCE: AVERAGE THE 12Z NAM REMAINED TO THE SOUTH/SOUTHWEST OF THE 12Z NCEP RUNS AND THE PREVIOUS NON NCEP RUNS. GIVEN THE MODEL UPGRADE EARLIER THIS MORNING...A COMPARISON BETWEEN THE 11/12Z OPERATIONAL GFS WAS MADE WITH THE 11/00Z RUN OF THE PARALLEL GFS FROM 11/00Z. THERE WAS A PRONOUNCED NORTHWARD SHIFT IN THE GFS BY LATE SATURDAY FROM NORTHERN CA TO A BROADER MID LEVEL LOW OVER WESTERN ORE AND SOUTHWEST WA. WHILE THE 11/12Z UKMET MADE A SHIFT NORTHWARD...IT WAS NOT NEARLY AS FAR NORTH AS THE GFS. AS A RESULT...THE 11/00Z RUN OF THE ECMWF HAS THE BEST CONTINUITY AND IT HAS THE SUPPORT OF THE UKMET AND ENSEMBLE MEANS. UPPER TROUGH LIFTING OUT OF THE WEST INTO THE GREAT LAKES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: CLOSEST TO THE ECMWF CONFIDENCE: AVERAGE THE NCEP MODEL RUNS FROM 12Z BOTH SUPPORTED THE IDEA OF SHORTWAVE ENERGY BEING QUICKER TO ROTATE AROUND THE MID LEVEL CYCLONE OVER EASTERN CANADA WHILE THE GFS SLOWED UP JUST A BIT THAN COMPARED WITH THE PREVIOUS RUNS. THE GEFS MEAN WAS SOUTH AND WEST OF THE EC ENSEMBLE MEAN WHICH GAVE MODEST SUPPORT FOR THE PREVIOUS ECMWF SOLN. FOR QPF PREFERENCES, SEE OUR QPF DISCUSSION FOR MODEL PREFERENCES FROM A PRECIPITATION FORECASTING VANTAGE POINT. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... BANN