MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1247 AM EDT SAT JUN 13 2015 VALID JUN 13/0000 UTC THRU JUN 16/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z NAM/GFS EVALUATION WITH PRELIMINARY PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. POSSIBLE CONVECTIVE LOW IN THE GULF MON/TUE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: WEAKER VERSION OF THE 00Z NAM / 12Z ECMWF / 12Z CMC CONFIDENCE: BELOW AVERAGE THE 12Z ECMWF/GEFS/CMC ENSEMBLE SCATTER LOW PLOTS HAVE TRENDED MORE TOWARDS THE IDEA OF A SURFACE LOW BETWEEN THE OFFSHORE WATERS OF TAMAULIPAS MEXICO AND MATAGORDA BAY TEXAS BY 12Z/16. THE LATEST DETERMINISTIC MODELS ARE MIXED WITH SURFACE LOW DEVELOPMENT BY THIS TIME FRAME...BUT THE THE 17Z WPC CONFERENCE CALL WITH NHC FROM FRIDAY LED TO A SURFACE TROUGH WITH ROUGHLY THE TIMING OF THE 00Z NAM/12Z ECMWF/12Z CMC SURFACE LOWS. A WEAKER VERSION OF THESE MODELS IS PREFERRED WITH BELOW AVERAGE CONFIDENCE DUE TO POOR RUN-TO-RUN AND DAY-TO-DAY MODEL CONTINUITY. SLOW...EWD MOVING SHORTWAVE OVER THE SRN/CNTRL PLAINS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-NAM COMPROMISE CONFIDENCE: ABOVE AVERAGE IN THE 700-500 MB LAYER...THE 00Z NAM APPEARS TO BE A DEEP OUTLIER WITH THIS SYSTEM. NON-NAM GUIDANCE IS REASONABLY SIMILAR HERE. SHORTWAVE PASSING THROUGH NEW ENGLAND THIS MORNING COLD FRONT SINKING DOWN THE MID-ATLANTIC COAST THROUGH SUN ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE NO MAJOR MODEL DIFFERENCES WERE OBSERVED WITH THIS SYSTEM. COLD FRONT PROGRESSING THROUGH THE DAKOTAS AND GREAT LAKES REGION ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE NO MAJOR MODEL DIFFERENCES WERE OBSERVED WITH THIS SYSTEM. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... OTTO