MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1222 PM EDT SAT JUL 09 2016 VALID JUL 09/1200 UTC THRU JUL 13/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION...INCLUDING THE NAM AND GFS ...MID LEVEL LOW CENTER CROSSING THE NORTHWEST THROUGH SUN... ...HEIGHT FALLS/SURFACE LOW IMPACTING THE NORTHERN PLAINS/UPPER MS VALLEY MON/TUES... PREFERENCE: BLEND OF THE 12Z GFS/00Z UKMET AND 00Z ECMWF CONFIDENCE: SLIGHTLY ABOVE AVERAGE THE MODELS ARE IN GOOD AGREEMENT IN TAKING A ROBUST MID LEVEL LOW ENTERING THE NORTHWEST U.S. OFF TO THE EAST OVER THE NEXT COUPLE OF DAYS...WITH THE HEIGHT FALLS AND AN ASSOCIATED SURFACE LOW CENTER IMPACTING THE NORTHERN PLAINS AND UPPER MS VALLEY THROUGH MON AND TUES. GRADUALLY THE 12Z NAM AND 00Z CMC TEND TO LAG THE 12Z GFS/00Z UKMET AND 00Z ECMWF SOLUTIONS...AND ESPECIALLY BY MON AND TUES AS THE ENERGY EJECTS ACROSS THE NORTHERN TIER OF THE CONUS. THE 12Z NAM ALSO GRADUALLY APPEARS TO BE TOO STRONG ALOFT. THE LATEST GEFS MEAN AND ECENS MEAN FAVOR THE GFS/UKMET/ECMWF CLUSTER...AND THIS CONSENSUS WILL BE PREFERRED. ...WEAK MID LEVEL SHORTWAVE ENERGY OVER THE LOWER MS/TN VALLEYS... PREFERENCE: BLEND OF THE 12Z GFS AND 00Z ECMWF CONFIDENCE: AVERAGE THE GUIDANCE CONTINUES TO ADVERTISE WEAK MID LEVEL ENERGY DIGGING THROUGH THE LOWER MS AND TN VALLEYS OVER THE NEXT COUPLE OF DAYS. THE 00Z UKMET AND 00Z CMC ARE GENERALLY THE WEAKEST SOLUTIONS WITH THIS...WITH THE 12Z NAM/12Z GFS AND 00Z ECMWF ALL A BIT DEEPER. THE NAM THOUGH TENDS TO BE THE STRONGEST OF ALL THE SOLUTIONS AND WITH ENERGY DIGGING A BIT FARTHER SOUTH. THE 12Z GFS AND 00Z ECMWF ARE FOCUSED A BIT FARTHER NORTH. THERE ARE STILL SOME TROUGH PROGRESSION DIFFERENCES BETWEEN THE GFS AND ECMWF...BUT THE GEFS MEAN AND ECENS MEAN BOTH SUPPORT THEIR RESPECTIVE DETERMINISTIC SOLUTIONS. WILL SUGGEST A BLEND OF THE GFS AND ECMWF AS A RESULT. ...MID LEVEL TROUGH/SURFACE LOW CROSSING THE NORTHEAST THROUGH SUN... PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE MODELS ARE IN SUFFICIENTLY GOOD ENOUGH AGREEMENT WITH THE TIMING AND DEPTH OF THIS SYSTEM THAT A GENERAL MODEL COMPROMISE CAN BE PREFERRED. ...NEXT MID LEVEL LOW CENTER/TROUGH IMPACTING THE NORTHWEST BY TUES... PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE MODELS TAKE ANOTHER MID LEVEL LOW CENTER DOWN THROUGH THE GULF OF AK THROUGH TUES...WITH AN ELONGATING TROUGH AXIS THAT SHOULD PIVOT ACROSS THE NORTHWEST U.S. AND SOUTHWEST CANADA. THERE IS RATHER GOOD AGREEMENT ON THE LARGE SCALE WITH THIS SYSTEM...SO FOR NOW A GENERAL MODEL COMPROMISE WILL BE PREFERRED. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ORRISON