MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1256 AM EDT SUN AUG 07 2016 VALID AUG 07/0000 UTC THRU AUG 10/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z NAM/GFS EVALUATION WITH PRELIMINARY PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ FRONT EXTENDING WWD THROUGH THE MID-ATLANTIC REGION THROUGH TUE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE NO SIGNIFICANT MODEL DIFFERENCES WERE NOTED WITH THIS SYSTEM. STAGNANT/PERSISTENT UPPER CIRCULATION ACROSS THE NERN GULF OF MEX ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NEAR THE GEFS/EC MEANS 12Z ECMWF IS THE CLOSEST DETERMINISTIC RUN TO THE ABOVE CONFIDENCE: BELOW AVERAGE THE LATEST ENSEMBLE MEANS ARE IN REASONABLY GOOD AGREEMENT WITH THE DISTURBANCE IN THE NERN GULF OF MEXICO...WHICH MATCHES CLOSEST TO THE 12Z ECMWF...ALTHOUGH THE LOW LEVEL LOW IN THE ECMWF IS EAST OF THE MEANS FOR LATE MON INTO TUE. THE 00Z GFS APPEARS A BIT DISORGANIZED AND WEAKER THAN THE REMAINING MODEL CONSENSUS. GIVEN THE COMPLEXITY OF THE WEAK STEERING CURRENTS AND POOR RUN TO RUN CONSISTENCY SEEN IN THE MODELS...CONFIDENCE REMAINS BELOW AVERAGE WITH THIS SYSTEM. REFER TO THE QPFPFD FOR DETAILS CONCERNING THE PREFERRED GUIDANCE FOR QPF. MID-LEVEL VORTICITY MAX TRACKING THROUGH THE CNTRL PLAINS TODAY AND INTO THE MID-MISS VALLEY MON MORNING ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: BLEND OF THE 00Z GFS/12Z ECMWF CONFIDENCE: SLIGHTLY BELOW AVERAGE THE 00Z NAM REMAINS MORE AMPLIFIED LIKE ITS PREVIOUS RUNS...AND THE MASS FIELDS OF THE 00Z GFS AND 12Z ECMWF REMAIN IN DECENT AGREEMENT. GIVEN QPF DETAILS DIFFER BETWEEN THE GFS AND ECMWF...REFER TO THE QPFPFD FOR DETAILS CONCERNING THE PREFERRED GUIDANCE FOR QPF. SLOW MOVING CLOSED LOW OVER THE PACIFIC NORTHWEST THROUGH MON SHORTWAVES SWINGING UNDERNEATH INTO THE WEST COAST ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~ PREFERENCE: 70% 12Z ECMWF / 30% 00Z GFS CONFIDENCE: SLIGHTLY ABOVE AVERAGE MODEL DIFFERENCES WITH THE SLOW MOVING CLOSED LOW OVER WASHINGTON BEGIN TUE MORNING WHEN THE 12Z CMC LAGS THE REMAINING MODEL CONSENSUS. THE GFS HAS BEEN THE MOST PROGRESSIVE BUT SITS AT THE LEADING EDGE OF THE LATEST ENSEMBLE GUIDANCE. THE MAJORITY OF THE LATEST ENSEMBLES RESIDE NEAR THE 12Z ECMWF...WHICH IS SLIGHTLY LESS PROGRESSIVE THAN THE 00Z NAM/GFS. REGARDING TWO SHORTWAVES FORECAST TO SWING THROUGH THE WRN U.S. BENEATH THE CLOSED LOW OVER THE PACIFIC NORTHWEST...THE 00Z NAM AND 12Z CMC DO NOT FIT IN WITH THE LATEST STRENGTHS SEEN IN THE REMAINING DETERMINISTIC/ENSEMBLE CONSENSUS REGARDING THE SHORTWAVE FORECAST TO REACH SRN ALBERTA/SASKATCHEWAN MON MORNING. THE NEXT WAVE EXPECTED TO REACH THE CNTRL CALIFORNIA COAST TUE EVENING...THE 00Z NAM...00Z GFS...12Z ECMWF MATCH REASONABLY WELL WITH THE POSITION AND STRENGTH OF THIS FEATURE COMPARED TO THE LATEST ENSEMBLE MEANS. OVERALL...THE 12Z ECMWF IS A GOOD FIT...WITH THE 00Z GFS A SECONDARY PREFERENCE. COLD FRONT TRACKING THROUGH THE UPPER MISS VALLEY AND GREAT LAKES TUE/WED ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~ PREFERENCE: 00Z GFS / 12Z ECMWF BLEND CONFIDENCE: AVERAGE THE GEFS/EC MEANS SHOW GOOD AGREEMENT WITH THE TIMING OF THE FRONT...WHICH IS A BIT SLOWER THAN THE GFS AND A BIT FASTER THAN THE ECMWF. THIS IS THE DIRECTION WPC IS LEANING FOR THE PREFERENCE. OTTO www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml...