MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 259 AM EDT SUN SEP 18 2016 VALID SEP 18/0000 UTC THRU SEP 21/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z MODEL EVALUATION AND FINAL PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ COLD FRONT OVER THE OHIO VALLEY TODAY...WEAKENING AS IT REACHES THE EAST COAST ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: AVERAGE NOT CONSIDERING POTENTIAL IMPACTS WITH JULIA...THE MODEL SHOW SIMILARLY WITH THIS SYSTEM...CERTAINLY THROUGH MON. TROPICAL CYCLONE JULIA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 00Z ECMWF CLOSEST TO NHC TRACK CONFIDENCE: REFER TO NHC DISCUSSION THE 03Z NHC ADVISORY FOR JULIA SHOWS DISSIPATION BY 00Z/21...WITH THE 00Z ECMWF BEST MATCHING THIS TRACK UNTIL THEN. THE 00Z UKMET REMAINS STRONGER THAN THE 00Z DETERMINISTIC CONSENSUS. GIVEN THE FORECAST FOR DISSIPATION...THE 00Z ECMWF IS CLOSEST TO THE NHC ADVISORY. THE 00Z NAM/GFS BRING JULIA MUCH CLOSER TO THE MID-ATLANTIC COAST AND MOST GUIDANCE SHOWS INTERACTION WITH AN APPROACHING UPPER LOW FROM THE WEST. TROPICAL DEPRESSION SEVENTEEN-E ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 00Z ECMWF CLOSEST TO NHC TRACK CONFIDENCE: REFER TO NHC DISCUSSION THE 00Z ECMWF IS CLOSEST TO THE TRACK SHOWN IN THE 03Z NHC ADVISORY ON T.D. SEVENTEEN-E. SHORTWAVE OVER THE CNTRL PLAINS...TRACKING INTO THE MID-ATLANTIC REGION ON MONDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 12Z ECMWF / 00Z ECMWF BLEND CONFIDENCE: BELOW AVERAGE LARGE ENSEMBLE SPREAD EXISTS WITH THIS SYSTEM. GIVEN POTENTIAL INTERACTIONS WITH THE REMNANTS OF JULIA...AND FOLLOWING THE NHC ADVISORY FOR THE TRACK...THE CLOSEST MATCH IS A BLEND BETWEEN THE OLDER 12Z ECMWF AND CURRENT 00Z ECMWF WITH THIS FEATURE. MID-LEVEL LOW SOUTH OF LOUISIANA EARLY THIS MORNING ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: AVERAGE DESPITE SOME MINOR DETAIL DIFFERENCES...THE MODELS SHOW SIMILARLY WITH THIS SYSTEM. MID-UPPER LEVEL LOW OFF OF THE SOUTHWESTERN U.S. COAST THIS MORNING AND TRACKING INLAND MON/TUE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: AVERAGE DESPITE SOME MINOR DETAIL DIFFERENCES...THE MODELS SHOW SIMILARLY WITH THIS SYSTEM. LOW AMPLITUDE UPPER TROUGH CROSSING THE N-CNTRL U.S. TODAY...AND CLIPPING NRN NEW ENGLAND TUE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: AVERAGE DESPITE SOME MINOR DETAIL DIFFERENCES...THE MODELS SHOW SIMILARLY WITH THIS SYSTEM. UPPER TROUGH OFF OF SRN BRITISH COLUMBIA MON...AMPLIFYING INTO A POSSIBLE CLOSED LOW ALONG THE NORTHWEST COAST BY WED MORNING ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON 00Z CMC BLEND CONFIDENCE: SLIGHTLY ABOVE AVERAGE ONLY THE 00Z CMC STANDS OUT SIGNIFICANTLY DIFFERENT FROM THE REMAINING MODELS WITH A SLOWER EVOLUTION REGARDING THIS FEATURE. NO MAJOR CHANGES SEEN WITH THE 00Z SUITE COMPARED TO THE PREVIOUS RUN. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... OTTO