MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1235 PM EDT SUN JUL 13 2014 VALID JUL 13/1200 UTC THRU JUL 17/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION WITH PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NAM/GFS INITIALIZATION ERRORS DO NOT APPEAR TO DEGRADE THEIR SHORT RANGE FORECASTS. DEEP/COLD LOW DROPPING INTO MI MON/TUE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: BLEND OF 12Z GFS AND 13/00Z ECMWF CONFIDENCE: AVERAGE THE 12Z NAM WAS ACTUALLY A LITTLE QUICKER TO FORM A CLOSED LOW OVER THE GREAT LAKES ON DAY 2 THAN IN PREVIOUS RUNS BUT REMAINED WAS ACTUALLY SLOW THAN THE GUIDANCE FROM 12/12Z AND 13/00Z THROUGH DAY 3 IN LIFTING THE FEATURE TO THE NORTHEAST THROUGH DAY 3. THE 12Z GFS INITIALLY WAS A BIT SLOWER TO FORM THE CLOSED MID LEVEL LOW ON DAY 2 BUT WAS ON THE FASTER SIDE OF THE GUIDANCE BY THE END OF DAY3 IN LIFTING THE SYSTEM NORTHEAST. THE MODEL AGREEMENT BETWEEN THE NAM/GFS WAS GENERALLY PRETTY GOOD BY THE END OF DAY 3. THIS STILL LEAVES THE 13/00Z ECMWF ON THE SOUTHWEST SIDE OF THE GUIDANCE THROUGH DAY 2 BEFORE IT COMES INTO AGREEMENT WITH THE NCEP MODELS. SO STILL PREFER A BLEND OF THE 13/12Z GFS AND 13/00Z ECMWF TO DEAL WITH DETAIL ISSUES ALOFT, WITH AVERAGE CONFIDENCE CONSIDERING THE EXISTING MODEL SPREAD. SHORTWAVES AFFECTING THE NORTHWEST/NORTHERN ROCKIES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: 00Z UKMET/00Z ECMWF COMPROMISE CONFIDENCE: ABOVE AVERAGE THE 12Z NCEP MODELS SHOWED SOME MINOR RUN TO RUN DIFFERENCES BUT THEY WERE SMALL AND DID NOT CLEARLY TELEGRAPH ANY TREND. THE FIRST SHORT WAVE ORIGINATING ALONG THE WEST COAST CROSSES THE PACIFIC NORTHWEST AND NORTHERN ROCKIES LATE ON DAY 1...AND THERE WAS A GOOD MODEL CONSENSUS WITH THE TRACK AND TIMING OF THIS SHORT WAVE. A SECOND SHORT WAVE DROPPING OUT OF WEST CENTRAL CANADA CROSSES THE NORTHERN ROCKIES LATE ON DAY 2 AND INTO DAY 3. A COMPROMISE OF THE 00Z UKMET/00Z ECMWF STILL SPLITS THE DIFFERENCE IN TIMING AND KEEPS THE SYSTEM FROM BECOMING TOO SHARP ALOFT, WHICH IS PREFERRED WITH ABOVE AVERAGE CONFIDENCE CONSIDERING THE MINIMAL GUIDANCE SPREAD. INVERTED UPPER TROUGH SKIRTING THE SOUTHWEST THROUGH MON ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL BLEND CONFIDENCE: ABOVE AVERAGE THE GUIDANCE IS CLUSTERED WELL WITH RESPECT TO THE INVERTED UPPER TROUGH CROSSING THE SOUTHWEST STATES INTO CA...INCLUDING THEIR DEPICTION OF THE MOISTURE PLUME ASSOCIATED WITH IT. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... BANN