MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 238 PM EDT SAT JUN 13 2015 VALID JUN 13/1200 UTC THRU JUN 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 SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. PATTERN NEAR BRITISH COLUMBIA/PACIFIC NORTHWEST TUE ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-NAM COMPROMISE CONFIDENCE: SLIGHTLY BELOW AVERAGE WHILE THE 12Z NAM IS A GOOD MATCH, SAILING ALONG WITH THE GROWING MODEL CONSENSUS WITH THE CLOSED CYCLONE OFFSHORE BRITISH COLUMBIA, ITS SOLUTION RUNS AGROUND WHEN IT SENDS A CLOSED 500 HPA CYCLONE INTO THE NORTHERN HIGH PLAINS. THE 12Z GFS/12Z CANADIAN SHOW STRONGER/PROGRESSIVE TROUGHING THROUGH THE CANADIAN PRAIRIE PROVINCES, WHICH IS POSSIBLE CONSIDERING THE STRENGTH OF THE SYSTEM NEAR HUDSON BAY. TO DEAL WITH THE GROWING UNCERTAINTY IN WESTERN CANADA, A COMPROMISE OF THE NON-NAM GUIDANCE IS PREFERRED HERE WITH SLIGHTLY BELOW AVERAGE CONFIDENCE. CONVECTIVE LOW IN THE GULF MONDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GFS/CANADIAN/ECMWF COMPROMISE CONFIDENCE: AVERAGE/SEE NHC OUTLOOKS THE 17Z WPC CONFERENCE CALL WITH NHC FROM FRIDAY LED TO A SURFACE TROUGH/LOW WHICH RESEMBLES A COMPROMISE OF 12Z GFS/12Z CANADIAN/12Z ECMWF. THIS SOLUTION IS PREFERRED WITH AVERAGE CONFIDENCE AS THE GUIDANCE HAS BEEN CONVERGING WITH THIS SYSTEM. FOR THE LATEST INFORMATION ON THE SYSTEM, SEE NHC TROPICAL WEATHER OUTLOOKS. SLOW-MOVING SHORTWAVE OVER THE SRN/CNTRL PLAINS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-NAM COMPROMISE CONFIDENCE: ABOVE AVERAGE IN THE 700-500 MB LAYER...THE 12Z NAM APPEARS TO BE A DEEP OUTLIER WITH THIS SYSTEM. NON-NAM GUIDANCE IS REASONABLY SIMILAR HERE. SHORTWAVE PASSING THROUGH NEW ENGLAND THIS MORNING COLD FRONT SINKING DOWN THE MID-ATLANTIC COAST THROUGH SUN COLD FRONT PROGRESSING THROUGH THE DAKOTAS AND GREAT LAKES REGION LOW NEAR SOUTHERN NEW ENGLAND TUESDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE NO MAJOR MODEL DIFFERENCES WERE OBSERVED WITH THESE SYSTEMS. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ROTH