MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1231 PM EDT SAT OCT 22 2016 VALID OCT 22/1200 UTC THRU OCT 26/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION...INCLUDING THE NAM AND GFS ...DEEP LOW PRESSURE CENTER IMPACTING THE NORTHEAST... PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE MODELS ARE IN GENERALLY GOOD AGREEMENT WITH THE EVOLVING DEEP LOW OVER NEW ENGLAND...AND THUS A GENERAL MODEL COMPROMISE WILL BE PREFERRED. ...SHORTWAVE/SURFACE LOW CROSSING THE NORTHERN PLAINS TODAY... ...ENERGY SHEARING ACROSS THE GREAT LAKES ON SUN... PREFERENCE: NON-CMC CONSENSUS CONFIDENCE: ABOVE AVERAGE THE MODELS SHOW A WEAK SHORTWAVE AND ASSOCIATED SURFACE WAVE CROSSING THE NORTHERN PLAINS WHICH WILL BE SHEARING EASTWARD THROUGH THE GREAT LAKES REGION ON SUNDAY. THE 00Z CMC REMAINS A BIT NORTH OF THE MULTI-MODEL CONSENSUS WITH THE TRACK OF THIS SYSTEM AND IS ALSO A TAD STRONGER. THE GUIDANCE IS OTHERWISE WELL-CLUSTERED ON A TRACK A TAD MORE SUPPRESSED. A NON-CMC CONSENSUS WILL BE PREFERRED. ...SHORTWAVE/SURFACE LOW MOVING TOWARD VANCOUVER ISLAND TONIGHT... PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE MODELS TAKE A SHORTWAVE TROUGH AND ASSOCIATED SURFACE LOW NORTHEAST TOWARD VANCOUVER ISLAND TONIGHT WHICH WILL BE BRUSHING THE PACIFIC NORTHWEST. VERY GOOD MODEL MASS FIELD AGREEMENT IS SEEN WITH THIS SYSTEM...SO A GENERAL MODEL COMPROMISE WILL BE PREFERRED. ...INTENSE SURFACE LOW DEVELOPING OFFSHORE THE NORTHWEST THROUGH TUES... PREFERENCE: BLEND OF THE 12Z GFS/00Z ECENS MEAN CONFIDENCE: AVERAGE THE MODELS CONTINUE TO TAKE THE CORE OF THE DEEP UPPER TROUGH/CLOSED LOW OVER THE GULF OF AK DOWN TO THE SOUTH OVER THE NEXT COUPLE OF DAYS WHICH WILL FOSTER A VERY DEEP AREA OF LOW PRESSURE OFF THE NORTHWEST COAST. THE 00Z ECMWF CONTINUES TO BE A DEEP OUTLIER...ALTHOUGH THERE HAS BEEN A CONSENSUS TOWARD A SOMEWHAT STRONGER SOLUTION FROM THE OTHER MODELS. THE EXCEPTION IS THE 00Z CMC WHICH FOR NOW IS THE WEAKEST SOLUTION WITH THIS SYSTEM AND FARTHEST NORTH. THE 00Z ECENS MEAN CONTINUES TO BE WEAKER RELATIVE TO THE DETERMINISTIC ECMWF...AND ACTUALLY AGREES RATHER WELL WITH THE 12Z GFS WHICH HAS TRENDED STRONGER. GIVEN THE SPREAD OF SOLUTIONS...THE GFS AND ECENS MEAN BOTH TEND TO REFLECT THE MODEL CONSENSUS...AND A BLEND OF THESE SOLUTIONS WILL BE PREFERRED. ...LOW PRESSURE DEVELOPMENT OFFSHORE CA ON TUES... PREFERENCE: NON-GFS CONSENSUS CONFIDENCE: AVERAGE THE GUIDANCE INDICATES ADDITIONAL SHORTWAVE ENERGY ROUNDING THE BASE OF THE DEEP TROUGH OFFSHORE THE WEST COAST BY TUES WHICH WILL AMPLIFY AND GENERATE A NEW AREA OF LOW PRESSURE. THE 12Z GFS IS THE WEAKEST SOLUTION...WITH THE REMAINING MODELS CLUSTERED AROUND A STRONGER SOLUTION. THERE IS SOME SPREAD WITH THE TIMING OF THIS SYSTEM...BUT FOR NOW WILL SUGGEST A NON-GFS CONSENSUS TO RESOLVE THESE DIFFERENCES. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ORRISON