MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 246 AM EDT FRI JUL 17 2015 VALID JUL 17/0000 UTC THRU JUL 20/1200 UTC ..SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z MODEL EVALUATION WITH FINAL PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NAM/GFS INITIALIZATION ERRORS DO NOT APPEAR TO IMPACT THEIR SHORT TERM FORECASTS. LINGERING TROUGHING IN THE WEST...EVENTUAL SMALL SCALE CLOSED UPPER LOW NEAR CALIFORNIA BY MON MORNING RECURVATURE OF HURRICANE DOLORES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 00Z ECMWF/UKMET/CMC COMPROMISE CONFIDENCE: BY DEFAULT/SEE NHC ADVISORIES THE GUIDANCE IS IN GENERAL AGREEMENT WITH THE TRACK OF DOLORES AND ITS UPPER LEVEL REMNANTS...BUT THE NAM DOES WEAKEN THE ASSOCIATED MID-LEVEL VORTICITY QUICKER THAN THE REMAINING MODEL CONSENSUS. THE 00Z GFS ENDS UP WEST OF THE 03Z NHC TRACK BY SUN NIGHT. THE 00Z ECMWF/UKMET/CMC REPRESENT A SOLUTION THAT IS CLOSE TO THE NHC TRACK WITH THE LOW LEVEL CIRCULATION...AND THE THREE MODELS AGREE WITH UPPER LEVEL TROUGHING ACROSS THE WEST THROUGH MON MORNING. SEE NHC PRODUCTS FOR THE LATEST INFORMATION ON DOLORES. COLD FRONT EXTENDING FROM THE GREAT LAKES TO THE CNTRL PLAINS BY SUN MORNING ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 00Z GFS / 00Z ECMWF COMPROMISE CONFIDENCE: SLIGHTLY ABOVE AVERAGE A GFS/ECMWF COMBO REPRESENTS THE MIDDLE OF THE LATEST SPREAD WITH TIMING/STRENGTH...AND IS IN AGREEMENT WITH THE LATEST ENSEMBLE MEANS. THE 00Z ECMWF SPED UP WITH THE PROGRESSION OF HE COLD FRONT...BUT NOT AS FAST AS THE 00Z NAM. DETAIL DIFFERENCES WITHIN THE MESOSCALE MAKE FOR A LESS PREDICTABLE QPF THAN FEATURES TRACKABLE ON THE SYNOPTIC SCALE. SYSTEM MOVING BY THE GREAT LAKES FRI TOWARDS NEW ENGLAND FOR SAT MORNING ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE NO MAJOR MODEL DIFFERENCES WERE NOTED WITH THIS SYSTEM. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... OTTO