MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1245 AM EDT SUN JUL 17 2016 VALID JUL 17/0000 UTC THRU JUL 20/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z MODEL EVALUATION INCLUDING PREFERENCES AND FORECAST CONFIDENCE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ SHORTWAVE ENERGY PIVOTING SOUTH-SOUTHEAST OF THE HUDSON BAY LOW... INITIAL FLAT UPPER TROUGH UPPER TROUGH ACROSS NORTHERN PLAINS- UPPER MIDWEST SUN-SUN NIGHT AMPLIFYING ACROSS THE GREAT LAKES AND NORTHEAST-MID ATLANTIC MON AND TUE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-NAM BLEND CONFIDENCE: ABOVE AVERAGE THERE IS GOOD NON-NAM CONSENSUS AMONG THE MODELS WITH THE TRACK AND DEPTH OF THE INITIAL SHORTWAVE ACROSS SOUTHERN MANITOBA/ONTARIO/QUEBEC AND GRAZING THE NORTHERN PLAINS-UPPER MIDWEST-UPPER GREAT LAKES SUN AND MON. THE NAM HOWEVER IS A LITTLE SLOWER/DEEPER WITH THIS FEATURE THROUGH MON AND (THUS) A TAD MORE AMPLIFIED WITH THE HEIGHT FALLS OVER THE UPPER GREAT LAKES. MON NIGHT AND TUE...AN UPPER JET STREAK DROPPING E-SE FROM THE UPPER MIDWEST INTO THE OH VALLEY WILL YIELD A SECONDARY SHORTWAVE DROPPING ACROSS SOUTHEAST ONTARIO-SOUTHERN QUEBEC AND INTO THE LOWER GREAT LAKES AND NORTHEAST. THE MODELS ARE WELL ALIGNED WITH THE TIMING OF THIS FEATURE...HOWEVER THE NAM IS THE MOST AGGRESSIVE WITH THE LONGWAVE TROUGH AMPLIFICATION INTO THE LOWER MID ATLANTIC REGION (FARTHEST SOUTH...INTO THE CAROLINAS...WITH THE 588DM 500 MB HEIGHTS BY TUE NIGHT). CLOSED UPPER LOW ALONG OR JUST OFF THE WA/OR COAST COAST AND ASSOCIATED POSITIVELY TILTED UPPER TROUGH INTO NORTHERN CA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-NAM/NON-CMC CONSENSUS CONFIDENCE: ABOVE AVERAGE THE CMC IS THE MOST AMPLIFIED SOLUTION IN TERMS OF MAINTAINING A CLOSED MID-UPPER LOW ALONG THE PAC NW COAST THROUGH THE END OF THE PERIOD (12Z WED)...WHILE ALSO EXHIBITING A MORE AMPLIFIED DOWNSTREAM RIDGE AXIS ACROSS THE NORTHERN ROCKIES. THE NAM MEANWHILE IS THE MOST ROBUST WITH SHORTWAVE ENERGY DROPPING ACROSS NORTHERN CA/SOUTHERN OR BY THE END F THE PERIOD. THE OPERATIONAL GFS/ECMWF/UKMET SOLUTIONS ARE WELL CLUSTERED WITH RESPECT TO THE TIMING AND STRENGTH OF THE UPPER TROUGH EVOLUTION...PARTICULARLY WITH THE OPENING OF THE 500 MB LOW ALONG THE PAC NW COAST BY 00Z WED. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... HURLEY