MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 233 PM EDT THU OCT 13 2016 VALID OCT 13/1200 UTC THRU OCT 17/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION WITH PREFERENCES/CONFIDENCE LEVELS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NAM/GFS INITIALIZATION ERRORS DO NOT SEEM TO DEGRADE THEIR SHORT RANGE FORECASTS. LOW OFFSHORE THE NORTHWEST SUNDAY NIGHT ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-CANADIAN COMPROMISE CONFIDENCE: ABOVE AVERAGE THE 12Z CANADIAN DIFFERS FROM THE REMAINING GUIDANCE IN SHOWING A MORE SOUTHERN CYCLONE HEADING FOR OREGON SUNDAY NIGHT AND A STRONGER LOW OFFSHORE HAIDA GWAII/QUEEN CHARLOTTE ISLANDS. NORMALLY, SYSTEMS WITHIN AN INTERMEDIATE STREAM OF THE WESTERLIES SUCH AS THE ONE OFFSHORE SOUTHEAST CANADA ARE OF LOW AMPLITUDE -- BELIEVE THE MORE SOUTHERN SYSTEM SHOULD BE MORE ENERGETIC/FARTHER NORTH AT THE SURFACE THAN SEEN IN THE CANADIAN. POST-TROPICAL CYCLONE SONGDA MOVING BY PACIFIC NW SAT ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE GUIDANCE, PARTICULARLY THE CANADIAN, UKMET, AND GFS, HAVE TRENDED UP TO 22 HPA WEAKER WITH POST-TROPICAL CYCLONE SONGDA SINCE THIS TIME YESTERDAY -- CORRECTING A BIAS SEEN WITH POST-TROPICAL CYCLONES IN MODEL GUIDANCE BEYOND 72 HOURS SINCE AT LEAST 2010. THE GUIDANCE HAS CONVERGED, WITH THE ECMWF SHIFTING NORTH AND THE OTHER GUIDANCE SHIFTING SOUTH. NO MODEL SHOWS THE SYSTEM BELOW 965 HPA AT THE MOMENT -- THEY SHOW A MORE PROBABLE SCENARIO ON THE VERGE OF OCTOBER LOW PRESSURE RECORDS FOR NORTHWEST WA. HOWEVER, THERE ARE STILL INDICATIONS WITHIN FSU CYCLONE PHASE SPACE DIAGRAMS THAT THE CYCLONE COULD ATTAIN A MODERATELY DEEP WARM CORE WHICH BECOMES INCREASINGLY SYMMETRIC PRIOR TO LANDFALL, HINTING THAT A RECURRENCE OF THE NOVEMBER 1 2006 CONVECTIVE CYCLONE OFFSHORE OREGON IS POSSIBLE. A COMPROMISE OF THE AVAILABLE GUIDANCE SHOULD DO WITH ABOVE AVERAGE CONFIDENCE. SYSTEM MOVING BY THE PACIFIC NORTHWEST THU PM/FRI AM SHORTWAVE TROUGH TRACKING INTO THE SOUTHEAST THIS WEEKEND COLD FRONT MOVING ACROSS THE EAST COAST TODAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ THE GUIDANCE SHOWS GOOD AGREEMENT WITH THIS FEATURE. PREFER A COMPROMISE OF THE AVAILABLE GUIDANCE TO DEAL WITH DETAIL ISSUES (SUCH AS TROUGH DEPTH IN THE SOUTHEAST) WITH ABOVE AVERAGE CONFIDENCE. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ROTH