MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 222 PM EDT FRI MAY 16 2014 VALID MAY 16/1200 UTC THRU MAY 20/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... ...12Z FINAL MODEL EVALUATION...INCLUDING THE CANADIAN GLOBAL..UKMET..ECMWF... NAM/GFS INITIALIZATION ERRORS DO NOT APPEAR TO SIGNIFICANTLY AFFECT THEIR LARGE SCALE OUTPUT. ...HIGH AMPLITUDE TROUGH IN THE NORTHEAST... PREFERENCE: BLEND OF 12Z OPERATIONAL MODELS...WITH SLIGHTLY LESS WEIGHT FROM 12Z NAM/GFS AFTER DAY 2 CONFIDENCE: ABOVE AVERAGE MODELS ARE VERY SIMILAR THROUGH DAY 2...SUNDAY EVENING..AFTER WHICH THE NAM BECOMES A LITTLE SLOWER THAN MODEL CONSENSUS WITH THE PROGRESSION OF DVLPG CLOSED LOW OVER NEW ENGLAND AND THE GFS BECOMES WEAKER WITH THE UPR TROF..PSBLY DUE TO STGR UPR LOW OVER HUDSON BAY. SENSIBLE WEATHER IMPACTS HOWEVER ARE RATHER MINOR. ...WAVES IN NORTHWEST FLOW DIVING INTO THE BASE OF THE EASTERN TROUGH... PREFERENCE: GENL MODEL BLEND CONFIDENCE: ABOVE AVERAGE MODELS CONTINUE TO SHOW REASONABLY GOOD AGREEMENT WITH HANDLING OF QUICK MOVING IMPULSES IN NW FLOW LEADING TO ISENTROPIC LIFT OVER STATIONARY BNDRY NEAR THE RED RIVER EWD ACRS THE LOWER MS VALLEY REGION FRI NIGHT INTO SUN. MODELS ALSO REMAIN SIMILAR WITH RETURN MSTR AVAILABILITY ALONG AND NORTH OF THE BNDRY. ...SYSTEM ADVANCING INTO THE PACIFIC NORTHWEST AND NORTHERN ROCKIES... PREFERENCE: NON-NAM BLEND OF 12Z OPERATIONAL MODELS. CONFIDENCE: AVERAGE MODELS SHOW DECENT AGREEMENT HERE WITH HANDLING OF UPR TROF AS THRU SUN EVENING THEN BEGIN TO DIVERGE SLIGHTLY INTO MON/MON EVENING WITH PIECE OF ENERGY THAT EJECTS OUT ACRS THE NRN ROCKIES AND REMAINS OF MID LEVEL CENTER THAT DROPS SWD ALONG THE NW PAC COAST. THE 12Z NAM IS A TAD MORE DVLPD WITH S/WV THAT EJECTS ACRS THE ROCKIES INTO SRN SASK/MANITOBA ON MON THAN GENL MODEL CONSENSUS. BOTH THE 12Z EC AND UKMET SHIFT UPR LOW A BIT MORE TO THE SOUTH OFF THE NRN CA COAST BY MON EVE THAN THE CANADIAN GLOBAL AND NAM..BUT IS RATHER CLOSE TO THE 00Z EC MEAN. IN BOTH CASES..THE SENSIBLE WEATHER IMPACTS ARE RELATIVELY MINOR AND LIKELY WITHIN THE AVERAGE ERROR OF MODELS AT THAT RANGE. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... SULLIVAN