MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 222 PM EDT SAT AUG 16 2014 VALID AUG 16/1200 UTC THRU AUG 20/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... FINAL 12Z NAM/GFS EVALUATION WITH PRELIMINARY MODEL PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NAM/GFS INITIALIZATION ERRORS DID NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. UPPER TROUGH AMPLIFYING ACROSS CALIFORNIA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 12Z GFS/12Z ECMWF COMPROMISE CONFIDENCE: SLIGHTLY ABOVE AVERAGE SIMILAR TO YESTERDAY, THE 12Z UKMET STILL KEEPS MOST OF THE ENERGY FARTHER TO THE SOUTHWEST THAN THE OTHER GUIDANCE. THE 12Z NAM CONTINUES TO BE TO THE RIGHT OF THE MODEL CONSENSUS. THE GFS AND ECMWF WERE CLOSE TO THE CONSENSUS SYSTEM MOVING ALONG THE CENTRAL US/CANADIAN BORDER ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: SLIGHTLY ABOVE AVERAGE OTHER THAN SOME SLIGHT DEPTH ISSUES ALOFT, THE GUIDANCE REMAINS IN GOOD AGREEMENT HERE. WE OPTED FOR A GENERAL MODEL COMPROMISE TO DEAL WITH THE LINGERING DETAIL ISSUES IN THE STRUCTURE OF THIS SYSTEM. AFTER 60 HOURS, THE CMC, UKMET, AND NAM BECOME DEEPER THAN THE OTHER GUIDANCE, BUT ARE SIMILAR BEFORE THAT TIME. SHORTWAVE MOVING FROM THE MIDWEST ALONG THE OHIO RIVER ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 12Z GFS/ECMWF/UKMET COMPROMISE CONFIDENCE: AVERAGE THE 12Z NAM AND CMC ARE DEEPER WITH THIS SYSTEM THAN THE MODEL CONSENSUS. SINCE THE OTHER GUIDANCE MAKES A STRONG CONSENSUS, WHICH AGREES WELL WITH THE 00Z ECMWF/06Z GEFS MEANS, WE PREFER A NON-NAM/CMC COMPROMISE HERE WITH AVERAGE CONFIDENCE. DEEP CYCLONE OVER SOUTHERN QUEBEC/ATLANTIC CANADA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL BLEND CONFIDENCE: ABOVE AVERAGE THE GUIDANCE IS IN GREAT AGREEMENT HERE. A GENERAL MODEL BLEND IS RECOMMENDED WITH ABOVE AVERAGE CONFIDENCE CONSIDERING THE MINIMAL GUIDANCE SPREAD. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... HAMRICK