MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 131 PM EST SAT FEB 13 2016 VALID FEB 13/1200 UTC THRU FEB 17/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION INCLUDING PREFERENCES/CONFIDENCE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ GFS/NAM INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. SYSTEM MOVING ACROSS THE MIDWEST TUESDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GFS/CANADIAN/ECMWF COMPROMISE CONFIDENCE: SLIGHTLY ABOVE AVERAGE THE 12Z UKMET IS AN OUTLIER WITH THIS SYSTEM, BECOMING FLAT AT THE SURFACE BECAUSE IT OVERDEVELOPS THE EASTERN SYSTEM. THERE IS JUST ENOUGH ROOM ALOFT FOR A BRIEF PERIOD WHERE A 700/500 HPA CYCLONE COULD CLOSE OFF. THE 00Z GLOBAL ENSEMBLE SPREAD FAVORS A COMPROMISE OF THE 12Z CANADIAN/12Z ECMWF/12Z GFS, WHICH IS PREFERRED WITH SLIGHTLY ABOVE AVERAGE CONFIDENCE. SYSTEM MOVING THROUGH THE EAST TUESDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GFS/CANADIAN COMPROMISE CONFIDENCE: AVERAGE THE 12Z UKMET WAS QUITE WOUND UP WITH THIS SYSTEM, 10 HPA DEEPER THAN THE OTHER GUIDANCE WITH THE LOW'S CENTRAL PRESSURE, THOUGH IT HAS TRENDED QUICKER/SLIGHTLY WEAKER FROM ITS 00Z RUN. SINCE THE UPPER LEVEL SYSTEM IS ENTERING A REGION OF CONFLUENT/QUICK FLOW, A LESS AMPLIFIED SOLUTION IS PREFERRED. A COMPROMISE OF THE 12Z CANADIAN/12Z GFS ACCOMPLISHES THIS TO SOME DEGREE AND SPLITS THE DIFFERENCE IN THE 00Z ENSEMBLE LOW CLUSTERING, SO THEIR SOLUTION IS PREFERRED WITH AVERAGE CONFIDENCE. SYSTEM SWINGING THROUGH NEW ENGLAND SUNDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ THE GUIDANCE IS IN GOOD AGREEMENT HERE, SO PREFER A GENERAL MODEL COMPROMISE WITH HIGH CONFIDENCE. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ROTH