MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1224 PM EDT SUN OCT 09 2016 VALID OCT 09/1200 UTC THRU OCT 13/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION INCLUDING THE NAM/GFS AND PRELIMINARY MODEL PREFERENCES ...POST-TROPICAL CYCLONE MATTHEW... PREFERENCE: NATIONAL HURRICANE CENTER FORECAST POST-TROPICAL CYCLONE MATTHEW IS FORECAST BY THE NATIONAL HURRICANE CENTER TO CONTINUE MOVING EAST-NORTHEASTWARD INTO THE OPEN WATERS OF THE ATLANTIC OCEAN. LINGERING RAIN AND WIND ACROSS PORTIONS OF THE MID-ATLANTIC AND NORTHEAST WILL COME TO AND END TONIGHT. THE 12Z RUNS OF THE NAM AND GFS BOTH PULL THE SYSTEM FARTHER NORTH RELATIVE TO PREVIOUS RUNS. THE OFFICIAL FORECAST TRACK OF THE NHC IS CLOSELY RESEMBLED BY A BLEND OF THE GFS AND THE 12Z ECMWF THROUGH TONIGHT. FROM MONDAY MORNING ONWARD, THE NHC TRACK IS MOST CLOSELY RESEMBLED BY THE 00Z ECMWF AND 00Z UKMET, WHICH KEEP THE SURFACE LOW FARTHER SOUTH. ...UPPER-LEVEL TROUGH MOVING FROM THE GREAT LAKES INTO THE NORTHEAST TODAY... PRELIMINARY PREFERENCE: 00Z ECMWF/06Z GEFS BLEND CONFIDENCE: AVERAGE THE NAM AND GFS ARE IN GOOD AGREEMENT WITH THE MODEL CONSENSUS THROUGH TONIGHT. BY MONDAY MORNING THE NAM AND GFS ARE MORE AMPLIFIED WITH THE TROUGH ACROSS NEW ENGLAND RELATIVE TO THE 00Z ECMWF/UKMET/CMC. THE GFS IS THE MOST AMPLIFIED SOLUTION, AND IS MORE AMPLIFIED THAN THE 06Z GEFS MEAN. ...UPPER LOW/POSITIVELY TILTED TROUGH IN BRITISH COLUMBIA... ...SFC LOW AND FRONTAL ZONE EMERGING EAST OF THE ROCKIES SUNDAY NIGHT... PRELIMINARY PREFERENCE: GFS/00Z ECMWF/00Z UKMET BLEND CONFIDENCE: SLIGHTLY ABOVE AVERAGE MODELS HANDLE THIS FEATURE SIMILARLY THROUGH MONDAY AFTERNOON. BY MONDAY NIGHT THE NAM BECOMES SLIGHTLY ON THE SLOW SIDE OF THE SPREAD (SIMILAR TO THE 00Z CMC). THROUGH WEDNESDAY, THE AGREEMENT BETWEEN THE GFS/00Z ECMWF/00Z UKMET SOLUTIONS IS GOOD ENOUGH TO RECOMMEND A BLEND OF THE THREE. ...SHORTWAVE MOVING FROM THE FOUR CORNERS INTO THE CENTRAL PLAINS TODAY/TONIGHT... PRELIMINARY PREFERENCE: GFS/00Z ECMWF BLEND CONFIDENCE: ABOVE AVERAGE A SHORTWAVE INITIALLY ACROSS THE FOUR CORNERS REGION IS FORECAST TO MOVE EAST INTO THE CENTRAL PLAINS ON MONDAY AND THEN QUICKLY INTO THE GREAT LAKES BY TUESDAY AS THE WAVE GETS PICKED UP BY STRONGER WESTERLY FLOW. AGREEMENT AMONG THE MODELS WITH RESPECT TO THE TIMING AND STRENGTH OF THIS FEATURE HAS IMPROVED OVER THE PAST DAY, AND THE NAM AND GFS NOW HANDLE THE WAVE COMPARABLY TO THE MODEL CONSENSUS. THE GFS AND THE 00Z ECMWF APPEAR TO BE THE TWO SOLUTIONS LOCATED MOST CENTRALLY WITHIN THE RELATIVELY SMALL RANGE OF SPREAD, SO WILL RECOMMEND A BLEND OF THESE TWO SOLUTIONS AT THIS TIME. ...SHORTWAVE REACHING THE CALIFORNIA COAST ON WEDNESDAY... PRELIMINARY PREFERENCE: GFS/06Z GEFS MEAN BLEND CONFIDENCE: AVERAGE A SHORTWAVE IS FORECAST BY ALL DETERMINISTIC GUIDANCE TO REACH THE CALIFORNIA COAST ON WEDNESDAY. THE NAM IS ON THE FAST SIDE OF THE SPREAD WITH THIS WAVE WHILE THE GFS IS WEAKER AND LOOKS MORE LIKE THE 00Z ECMWF ENS MEAN/06Z GEFS MEAN SOLUTIONS. WILL RECOMMEND A BLEND OF THE GFS AND THE 06Z GEFS MEAN AT THIS TIME. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... RYAN