MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 240 AM EDT WED JUL 30 2014 VALID JUL 30/0000 UTC THRU AUG 02/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... FINAL 00Z MODEL EVALUATION ~~~~~~~~~~~~~~~~~~~~~~~~~~ LARGE UPPER TROUGH ACROSS THE PLAINS AND EAST ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: MODEL BLEND OF GFS/ECMWF/MEANS CONFIDENCE: ABOVE AVERAGE THE LARGE ANOMALOUS TROUGH OVER THE ERN PORTION OF THE COUNTRY WILL REMAIN SO THROUGH FRI. THE UPPER VORTEX WILL LOOP NEAR JAMES BAY BEFORE SHEARING OFF TO THE NORTH AND EAST INTO NRN QUEBEC... WHILE UPSTREAM DYNAMICS GRADUALLY DIG THROUGH THE UPPER MIDWEST BEFORE SETTLING OVER THE MID MS VALLEY/WRN OH VALLEY. THE AMPLIFIED UPPER TROUGH AXIS WILL ACTUALLY RETROGRADE DURING THE FCST PERIOD FROM NEAR THE EAST COAST TO THE MS RIVER... WHILE THE ASSOCIATED SURFACE COLD/STATIONARY FRONT WILL FOLLOW SUIT FROM OVER THE WRN ATLANTIC TO THE ERN SEABOARD. OVERALL THE GUIDANCE IS IN SOLID AGREEMENT WITH THIS LONG WAVE FEATURE... LITTLE SPREAD OTHER THAN DETAIL DIFFERENCES AND PERHAPS THE 00Z NAM BEING A SLIGHT OUTLIER SHIFTING THE TROUGH AXIS/FRONT FARTHER WEST BY SAT MORNING. WPC WILL RECOMMEND A BLEND OF THE GFS/ECMWF AND ITS MEANS FOR THE FCST PERIOD. SOUTHERN PLAINS/LOWER MS VALLEY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: BLEND OF THE GUIDANCE CONFIDENCE: ABOVE AVERAGE A SMALL SCALE STRING OF SHORT WAVE DYNAMICS ASSOCIATED WITH THE MID-LEVEL LOW OVER NRN UT WILL STREAM INTO THE SRN PLAINS ON WED BEFORE REACHING THE LOWER MS VALLEY ON THURS. THIS WILL RESULT IN POTENTIAL HEAVY RAIN IN AN ACTIVE NWRLY FLOW REGIME... AS A SURFACE WAVE PROPAGATES DOWNSTREAM. HEAVY CONVECTIVE RAINS THIS EVENING OVER ERN CO WILL EXPAND INTO SWRN KS AND OK/TX PANHANDLES BEFORE ADVANCING INTO OK/EXTREME SRN KS ON WED. THE SHORT WAVE DYNAMICS BEGIN TO SHEAR OUT A BIT ON THURS INTO THE SOUTH BUT HEAVY RAIN WILL STILL THREAT THE ARKLATEX INTO MS. OVERALL THE GUIDANCE SHOWS RATHER SOLID AGREEMENT ON THE DEPTH AND PROGRESSION OF THIS DETAILED FEATURE WITH A FEW MINOR DIFFERENCES WITH QPF. WPC WILL RECOMMEND A BLEND OF THE GUIDANCE ON THE PATTERN AND FOR MORE ON THE QPF... PLEASE REFER TO THE LATEST QPFPFD. INTER-MOUNTAIN WEST ~~~~~~~~~~~~~~~~~~~ PREFERENCE: GFS/ECMWF BLEND CONFIDENCE: AVERAGE AN UPPER RIDGE WILL RE-POSITION ITSELF OVER NRN MEXICO AND AZ/NM TO CALM THE MONSOONAL FETCH SOME DURING THE FCST PERIOD. HOWEVER... AN ARRAY OF SMALL SCALE IMPULSES IS ANTICIPATED TO ADVECT INTO THE INTER-MOUNTAIN WEST AHEAD OF DECENT THICKNESS PACKING/FRONTAL ZONE OVER WA/OR. IT STILL APPEARS SOME MID-LEVEL DYNAMICS WILL STREAM THROUGH CENTRAL CA INTO NV BEFORE PROCEEDING DOWNSTREAM THROUGH UT INTO CO... WHILE SOME PAC DYNAMICS ORGANIZE ALONG NRN CA/OR COAST BEFORE MOVING INTO THE INTERIOR NW. REALLY TOUGH TO GAUGE WHICH MODEL IS HANDLING THESE FEATURES CORRECTLY BUT THE GFS AND ECMWF SEEM TO BE MOST SIMILAR AND A BLEND OF THESE TWO SEEMS WISE. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... MUSHER