MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 246 PM EDT MON JUL 27 2015 VALID JUL 27/1200 UTC THRU JUL 31/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION...INCLUDING FINAL PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ STRONG UPPER TROUGH CROSSING THE DAKOTAS ON TUE WITH ATTENDANT COLD FRONT CROSSING THE MID-MISS VALLEY EARLY WED ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: SLIGHTLY ABOVE AVERAGE NO SIGNIFICANT TIMING/STRENGTH DIFFERENCES WERE SEEN IN THE MODELS FOR THIS SYSTEM. LOW-MID LEVEL TROUGH AXIS IMPACTING THE SOUTHEAST/FL PENINSULA THROUGH THU POTENTIAL UPPER TROUGH / CLOSED LOW REDEVELOPMENT IN THE WRN ATLANTIC BY MID TO LATE WEEK ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 12Z GFS CONFIDENCE: SLIGHTLY BELOW AVERAGE WHILE CONFIDENCE IS REDUCED GIVEN GREATER THAN AVERAGE ENSEMBLE SPREAD...THERE IS ENOUGH AGREEMENT AMONG THE ENSEMBLES TO EXCLUDE THE DEEP/OUTLIER 00Z UKMET AS A LIKELY SOLUTION OFF OF THE SOUTHEAST COAST BY THU. THE 12Z UKMET IS LESS STRONG...BUT STILL ON THE STRONG SIDE OF THE DETERMISTIC GUIDANCE. THERE IS BETTER SUPPORT FROM THE ENSEMBLE MEANS TOWARD THE 12Z GFS IDEA THROUGH THU EVENING. THE 12Z NAM AND 00Z ECMWF HAVE BEEN REMOVED FROM THE PREFERENCE BECAUSE OF THE SUBTLE 12Z MODEL SHIFT AWAY FROM LOWS FARTHER EAST...SIMILAR TO THE 12Z NAM AND 00Z ECMWF. THE 12Z ECMWF IS NOW VERY CLOSE TO THE COAST...BUT AGAIN...ENSEMBLE SUPPORT IS FARTHER EAST...WITH POSITIONS AVERAGING NEAR THE 12Z GFS...WHICH ALSO FITS THE MODE OF THE PAST SEVERAL RUNS OF THE DETERMINISTIC MODELS. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... OTTO