MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 240 AM EDT SUN JUL 13 2014 VALID JUL 13/0000 UTC THRU JUL 16/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z 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 00Z GFS/00Z ECMWF CONFIDENCE: AVERAGE THE 00Z NAM IS ON THE FASTER EDGE OF THE MODEL SOLUTION ENVELOPE WITH ITS DEPICTION OF THE CLOSED MID- LEVEL LOW AND ITS LONGWAVE TROUGH POSITION. THE 00Z GFS HAS CONTINUED TO SLOW ITS PROGRESSION WITH RESPECT TO THE ANOMALOUS MID-LEVEL CYCLONE OVER ITS PAST DAY OF RUNS. THE 00Z ECMWF IS STILL ON THE SOUTHWEST SIDE OF THE GUIDANCE THROUGH DAY 2. AFTER THAT...THE ECMWF SOLUTION SPEEDS UP AND CONVERGES TO THE CONSENSUS POSITION. DESPITE THE DIFFERENCES IN THE TIMING OF THE EXIT OF THE CLOSED MID LEVEL SYSTEM AND EVOLUTION OF THE LONG WAVE TROUGH...THERE WAS GENERALLY GOOD MODEL AGREEMENT CONCERNING THE TIMING OF THE FRONT ON THE EAST COAST. PREFER A COMPROMISE OF THE 00Z GFS AND 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 FIRST SHORT WAVE ORIGINATING ALONG THE WEST COAST CROSSES THE PACIFIC NORTHWEST AND NORTHERN ROCKIES DURING DAY 2...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 ON DAY 3. A COMPROMISE OF THE 00Z UKMET/00Z ECMWF 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... HAYES/ROTH