MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1222 AM EDT WED JUN 22 2016 VALID JUN 22/0000 UTC THRU JUN 25/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z NAM/GFS EVALUATION INCLUDING INITIAL PREFERENCES AND FORECAST CONFIDENCE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ MID LEVEL CLOSED LOW TRACKING FROM THE PACIFIC NORTHWEST TO THE NORTHERN PLAINS SURFACE LOW ACROSS THE NORTHERN PLAINS FRI INTO SAT ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 00Z GFS/12Z ECMWF BLEND CONFIDENCE: ABOVE AVERAGE THE 00Z NAM WAS CLOSE TO THE CONSENSUS AS THE CLOSED MID LEVEL SYSTEM CROSSES THE PACIFIC NORTHWEST...THEN SLOWS A BIT AS IT REACHES THE NORTHERN PLAINS EARLY SAT. HOWEVER...THE 00Z NAM IS FURTHER NORTHWEST WITH SURFACE LOW ASSOCIATED WITH THE CLOSED MID LEVEL SYSTEM (TOO FAR INTO THE COOL AIR...AS THE NAM IS WONT TO DO). THE 00Z GFS IS CONSISTENT WITH ITS PAST THREE RUNS...AND IS CLOSE TO THE MODEL CONSENSUS WITH THE MID LEVEL AND SURFACE SYSTEMS. THEREFORE...A BLEND OF THE 00Z GFS/12Z ECMWF IS PREFERRED HERE. SHORT WAVE MOVING FROM THE UPPER GREAT LAKES ACROSS THE OH VALLEY LOW PRESSURE TRACKING FROM THE MID MS VALLEY TO THE OH VALLEY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~ PREFERENCE: 12Z ECMWF/12Z UKMET/18Z GEFS MEAN CONFIDENCE: AVERAGE THE 00Z NAM IS CLOSE TO THE CONSENSUS WITH THE SURFACE LOW AS IT TRACKS ACROSS THE MID MS VALLEY...BUT BECOMES FASTER AND FURTHER SOUTHEAST AS IT APPROACHES THE MID ATLANTIC THU. THE 00Z GFS REMAINS SLOWER THAN THE CONSENSUS WITH THE SURFACE LOW AS IT CROSSES THE OH VALLEY WED NIGH INTO THU MORNING (AND HAS REMAINED CONSISTENTLY SLOW THE PAST THREE CYCLES). THERE IS BETTER AGREEMENT WITH THE TIMING OF THE LOW ACROSS THE OH VALLEY USING THE 12Z ECMWF/12Z UKMET AND THE 18Z GEFS MEAN...WHICH IS FASTER THAN THE 00Z GFS. DUE TO THE TIMING DIFFERENCES MENTIONED ABOVE...FORECAST CONFIDENCE IS ONLY AVERAGE. COLD FRONT AND SURFACE LOW MOVING ACROSS THE NORTHEAST FRI INTO SAT ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 00Z GFS/12Z ECMWF CONFIDENCE: AVERAGE THE 00Z NAM IS SLOWER AND DEEPER WITH THE SURFACE LOW AS IT TRACKS FROM THE NJ COAST TO A POSITION EAST OF NOVA SCOTIA FRI AFTERNOON AND EVENING. THE 00Z GFS IS CLOSER TO THE CONSENSUS...AND IN GOOD AGREEMENT WITH THE 12Z ECMWF AND THE ECMWF/GEFS MEAN POSITIONS. AFTER REMAINING CLOSE TO THE CONSENSUS THOUGH EARLY FRI...THE 12Z UKMET TRACKS WEST OF THE CONSENSUS AS IT PASSES EAST OF NOVA SCOTIA. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... HAYES