MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 228 PM EDT SAT MAY 09 2015 VALID MAY 09/1200 UTC THRU MAY 13/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION WITH PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ NAM/GFS INITIALIZATION ERRORS DO SEEM DEGRADE THEIR SHORT RANGE FORECASTS. CLOSED LOW MOVING INTO THE WEST COAST LATE MONDAY ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-GFS COMPROMISE CONFIDENCE: SLIGHTLY ABOVE AVERAGE THE 12Z GFS/12Z GEFS MEAN REMAIN ON THE NORTHERN SIDE OF THE GUIDANCE SPREAD, WITH MOST OF THE REMAINING GUIDANCE DOWN SOUTH. A BLOCKING HIGH OVER WESTERN CANADA COMBINED WITH SOME UPSTREAM RIDGING IN THE PACIFIC SHOULD LEAD TO A MORE SOUTHERLY SOLUTION. THE PREFERENCE IS FOR A 12Z NAM/12Z ECMWF/12Z CANADIAN/12Z UKMET COMPROMISE WITH SLIGHTLY ABOVE AVERAGE CONFIDENCE. DEEP CYCLONE MOVING THROUGH THE ROCKIES/PLAINS/MIDWEST ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ PREFERENCE: NON-NAM COMPROMISE CONFIDENCE: ABOVE AVERAGE OUTSIDE OF THE MORE SOUTHERLY/STRONGER NAM, THE GUIDANCE IS IN VERY GOOD AGREEMENT HERE. PREFER A COMPROMISE OF THE 12Z GFS/12Z CANADIAN/12Z UKMET/12Z ECMWF WITH ABOVE AVERAGE CONFIDENCE. TROPICAL STORM ANA ~~~~~~~~~~~~~~~~~~ PREFERENCE: GFS/UKMET COMPROMISE CONFIDENCE: BY DEFAULT/SEE NHC ADVISORIES THE LATEST NHC TRACK IS CLOSEST TO THE 12Z UKMET/12Z GFS ONCE IT MOVES BACK OFFSHORE NEAR THE 40N 70W BENCHMARK -- MOST GUIDANCE IS AGREEABLE WITH THE TRACK OF THIS SYSTEM OVER THE NEXT COUPLE DAYS. FOR THE LATEST INFORMATION ON ANA...SEE NHC ADVISORIES. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ROTH