MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 236 AM EDT THU OCT 27 2016 VALID OCT 27/0000 UTC THRU OCT 30/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z MODEL EVALUATION WITH PREFERENCES/CONFIDENCE INTERVALS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. SYSTEMS APPROACHING THE WEST COAST LATE SATURDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GFS/ECMWF/UKMET COMPROMISE CONFIDENCE: SLIGHTLY ABOVE AVERAGE THE GUIDANCE GENERALLY AGREES ON A SYSTEM WITH SOME DEPTH MOVING TOWARDS NORTHERN CA EARLY SUNDAY. TO ITS NORTH, THE GUIDANCE IS A BIT LESS AGREEABLE, WITH THE 00Z CANADIAN AND TO SOME DEGREE THE 00Z NAM SHOWING A SEPARATE NEARLY CLOSED SYSTEM OFFSHORE WA STATE. CONSIDERING THE SYSTEM MOVING TOWARDS NORTHERN CA AND A SEPARATE SHORTWAVE MOVING THROUGH NORTHERN BRITISH COLUMBIA, THERE DOES NOT APPEAR TO BE ENOUGH ROOM IN THE FLOW PATTERN FOR A SEPARATE CLOSED CYCLONE OFFSHORE THE NORTHWEST. THE 00Z NAM ALSO BRINGS A BONUS SHORTWAVE SATURDAY NIGHT INTO THE NORTHWEST/SOUTHERN BRITISH COLUMBIA WHICH IS MORE SIGNIFICANT (BROADER AND OF MORE DEPTH) THAN THE OTHER GUIDANCE -- ITS USUAL BIAS. A COMPROMISE OF THE 00Z GFS/00Z UKMET/00Z ECMWF DEALS WITH THE NAM ISSUE IN THE NORTHWEST, LATITUDE ISSUES OF THE CYCLONE OFFSHORE NORTHERN CA, AND MAKES LESS OF ANY ENERGY OFFSHORE THE PACIFIC NORTHWEST. THIS IDEA IS PREFERRED WITH SLIGHTLY ABOVE AVERAGE CONFIDENCE. SYSTEM MOVING INTO CA FRI/GREAT LAKES SUN AM ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-NAM COMPROMISE CONFIDENCE: SLIGHTLY ABOVE AVERAGE THE 00Z NAM IS THE STRONGEST/SLOWEST OF THE GUIDANCE WITH THIS SYSTEM -- ITS USUAL BIAS. THERE HAS BEEN A QUICKENING OF THE GFS/UKMET/ECMWF GUIDANCE WITH THIS FEATURE. AS THE SYSTEM IS ENTERING CONFLUENT FLOW ALOFT, A QUICKER SOLUTION MAKES SENSE. A COMPROMISE OF THE 00Z UKMET, GFS, ECMWF, AND CANADIAN GUIDANCE HERE SHOULD RECTIFY THE ISSUE. THIS IS PREFERRED WITH AVERAGE CONFIDENCE. SYSTEM MOVING THROUGH SOUTHEAST CANADA FRI/SAT ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-CANADIAN COMPROMISE CONFIDENCE: ABOVE AVERAGE THE 00Z CANADIAN IS SLOW/DEEP WITH THIS SYSTEM. CONSIDERING THE ZONAL FLOW THE SYSTEM IS EMBEDDED WITHIN, THIS SORT OF SOLUTION DOES NOT APPEAR LIKELY. A COMPROMISE OF THE 00Z NAM/00Z ECMWF/00Z GFS/00Z UKMET IS PREFERRED WITH ABOVE AVERAGE CONFIDENCE. SYSTEM MOVING THROUGH NEW ENGLAND THU/FRI ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ THE GUIDANCE SHOWS GOOD AGREEMENT WITH THESE SYSTEMS. PREFER A GENERAL MODEL COMPROMISE TO DEAL WITH ANY DETAIL ISSUES WITH ABOVE AVERAGE CONFIDENCE. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ROTH