000 FXUS10 KWNH 111857 PMDHMD MODEL DIAGNOSTIC DISCUSSION NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD 156 PM EST WED FEB 11 2009 VALID FEB 11/1200 UTC THRU FEB 15/0000 UTC ...SEE NOUS42 KWNO ADMNFD FOR THE STATUS OF THE UPPER AIR INGEST... FINAL 12Z MODEL EVALUATION INCLUDING THE 12Z ECMWF MODEL INITIALIZATION ERRORS ARE DESCRIBED UNDER THE RELEVANT SYSTEM HEADING. ...SYSTEM NEARING THE WEST COAST ON SAT... PREFERENCE: GFS/ECMWF/GEFS MEAN COMPROMISE BY FRI NIGHT-SAT THE GFS BECOMES FASTER THAN THE NAM WITH THE SEWD PROGRESSION OF THE OVERALL SYSTEM. REMAINING OPERATIONAL GUIDANCE SHOWS A DECENT AMOUNT OF SPREAD. THE 12Z ECMWF HAS MODESTLY ADJUSTED CLOSER TO THE GFS DETAILS. THE UKMET/CANADIAN GLBL TRACK THE SYSTEM FARTHER SWD THAN THE GFS... WITH THE UKMET EWD OF THE CMC. THE 09Z SREF/12Z GEFS MEANS SUPPORT A SFC AND MID LVL SOLN CLOSE TO OR A TAD SLOWER THAN THE GFS WHILE THE 00Z ECMWF MEAN IS SLIGHTLY TO THE N OF THE GFS. BASED ON BEST CLUSTERING OF MODEL/ENSEMBLE GUIDANCE AND LACK OF ANY GFS/NAM TRENDS TOWARD A MORE SRN UKMET/CMC SCENARIO... WILL RECOMMEND AN INTERMEDIATE SOLN REPRESENTED BY A COMPROMISE AMONG THE GFS/ECMWF AND SLIGHTLY WEAKER 12Z GEFS MEAN. ...TROF/EMBEDDED CLOSED LOW ENTERING THE WEST ON FRI... PREFERENCE: GFS/ECMWF/GEFS MEAN COMPROMISE ASIDE FROM MINOR TIMING/DETAIL DIFFS THAT ARE TYPICALLY DIFFICULT TO RESOLVE 2-3 DAYS OUT IN TIME... THE GFS/NAM PROVIDE SIMILAR SOLNS ALOFT. THE NAM TRACKS THE ERN PAC SFC LOW SLOWER/SWD VERSUS THE GFS AS IT MOVES INLAND BY LATE FRI/FRI NIGHT... AND IS STRONGER/NWWD VERSUS THE GFS WITH LOW PRESSURE CROSSING THE GRTBASIN. THE 12Z ECMWF HAS ADJUSTED NWD TO A SOLN THAT IS EVENTUALLY SLOWER/WEAKER THAN THE NAM WITH THE SFC LOW REACHING NRN CA... AND IS WEAKER THAN THE GFS OVER THE GRTBASIN. THE UKMET/ECMWF HOLD MORE MID LVL ENERGY ALONG THE COAST BUT IS NOT QUITE AS EXTREME AS THE UKMET. THE CANADIAN GLBL IS A COMPROMISE WITH THE SFC LOW TRACKING INTO NRN CA FRI BUT THEN IS SLOWER THAN MOST OPERATIONAL SOLNS ASIDE FROM THE UKMET ACROSS THE GRTBASIN. WILL LEAN TOWARD A COMPROMISE AMONG THE GFS/ECMWF AND GEFS MEAN... WHICH IS A TAD SLOWER OVER THE GRTBASIN... BASED ON PREFERRED EVOLUTION WITH UPSTREAM ERN PAC FLOW BY FRI NIGHT-SAT. ...WEST COAST TO ERN CONUS SYSTEM WED-SAT... PREFERENCE: NAM/GFS/00Z ECMWF BLEND GUIDANCE SHOWS REASONABLE CONSENSUS AS THE SYSTEM CROSSES THE WEST. FROM THE PLAINS EWD THE GFS TRENDS SOMEWHAT FASTER THAN THE NAM WITH THE MID LVL SHRTWV BUT THEIR PATHS ARE SIMILAR. LIKEWISE THE SFC EVOLUTION IN THE GFS IS SIMILAR TO THE NAM WITH A HINT OF FASTER PROGRESSION. THE ECMWF TRENDS SLIGHTLY WEAKER THAN ITS PREVIOUS RUN AND GFS/NAM WITH THE MID LVL SHRTWV AND LEANS TOWARD THE GFS TIMING... BUT TRACKS THE SFC LOW A LITTLE NWD OF THE GFS/NAM FROM THE PLAINS INTO THE OH VALLEY. GREATER WEAKENING OF THE MID LVL SHRTWV IN THE 12Z ECMWF YIELDS A WEAKER AND SLOWER SFC SOLN THAN MODEL CONSENSUS BY FRI NIGHT-SAT. THE CANADIAN GLBL IS ON THE AMPLIFIED SIDE OF THE SOLN ENVELOPE WITH THE MID LVL SHRTWV AND HAS BEEN TRENDING TOWARD THE MORE NRN GFS/NAM/EC SOLNS FOR THE PAST DAY. THUS WOULD LIKE TO GIVE LESS WEIGHT TO ITS FARTHER NWD COASTAL LOW AT THE SFC BY F84 LATE SAT. ON THE OTHER HAND THE UKMET IS WEAKER SFC/ALOFT THAN OTHER MODELS FROM THE PLAINS EWD... THOUGH SREF/GEFS ENSEMBLES CONTINUE TO SHOW POTENTIAL FOR A MORE SUPPRESSED AND/OR FASTER SFC PROGRESSION FROM THE PLAINS EWD. WITH TRENDS FROM THE PAST DAY POSSIBLY SUPPORTIVE OF THE WEAKER 12Z ECMWF SHRTWV BUT CONSENSUS NOT ENDORSING THE SLOW 12Z EC SFC TIMING... WILL MAINTAIN PREFERENCE FOR A COMPROMISE/BLEND AMONG THE GFS/NAM/00Z ECMWF THAT CONSTITUTE THE BEST OPERATIONAL CLUSTER AT THIS TIME. ...ERN CANADA CLOSED LOW BRUSHING NRN NEW ENGLAND... PREFERENCE: GFS/ECMWF COMPROMISE DURING FRI-SAT THE GFS AND SIMILAR UKMET TRACK THE CLOSED LOW INCREASINGLY FARTHER SWD THEN EWD VERSUS THE NAM. THE CANADIAN GLBL AND FARTHER SWD ECMWF/00Z EC ENSEMBLE MEAN ARE FASTER THAN THE GFS TO VARYING DEGREES... BUT SLOWER TREND OF THE 12Z ECMWF VERSUS THE 00Z RUN DECREASES THE SOLN SPREAD SOMEWHAT. 09Z SREF/12Z GEFS MEANS ALSO SUPPORT FASTER TIMING THAN THE NAM. OVER THE PAST 1-2 DAYS THE NAM HAS NOT SHOWN A PRONOUNCED TREND AND IN FACT HAS ADJUSTED A LITTLE NWD VERSUS ITS PREVIOUS RUN... IN CONTRAST TO THE GFS THAT HAS BEEN TRENDING SWD/SEWD TOWARD THE FASTER ECMWF SCENARIO. WITH THE NAM A SLOW OUTLIER AND STILL SOME MODEST SCATTER AMONG THE DOMINANT FASTER CLUSTER... WILL RECOMMEND A COMPROMISE BETWEEN THE GFS AND ECMWF. ...SYSTEM INITIALLY OVER THE PLAINS/MS VALLEY... PREFERENCE: GFS AND OTHER NON-NAM SOLNS THE NAM 850 MB TEMP ANALYSIS IS 2-3 C LOWER THAN VALUES REPORTED BY RAOBS FROM ERN IA THRU NEB/NERN KS INTO WRN SD. THE GFS OFFERS A BETTER FIT TO DATA. AT 250 MB... THE NAM/GFS WIND ANALYSES SHOW SPEEDS THAT ARE 10-15 KTS LOWER THAN OBSERVED OVER SERN MI AND CNTRL IL/ERN IA... AND THE GFS IS 10-15 KTS WEAK OVER NWRN LA INTO AR. THE NAM BECOMES A TAD SLOWER THAN THE GFS AND MOST OTHER MODEL AND ENSEMBLE MEAN SOLNS AS THE SYSTEM DEPARTS FROM NEW ENGLAND AFTER F36 LATE THU. DUE TO THIS DIFFERENCE AND BETTER INIT OF LOW LVL TEMPS IN THE GFS... WOULD RECOMMEND THE GFS AND OTHER NON-NAM SOLNS. ...MODEL TREND GRAPHICS AT WWW.HPC.NCEP.NOAA.GOV/HTML/MODEL2.SHTML... ...500 MB FORECASTS AT WWW.HPC.NCEP.NOAA.GOV/H5PREF/H5PREF.SHTML RAUSCH $$