MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1152 PM EST SUN MAR 02 2014 VALID MAR 03/0000 UTC THRU MAR 06/1200 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 00Z MODEL EVALUATION...INCLUDING THE NAM AND GFS ...SRN STREAM TROUGH CROSSING THE LOWER MS VALLEY/SOUTHEAST AND MID-ATLANTIC THROUGH MON... ...ASSOCIATED SURFACE LOW TRACKING INTO THE SOUTHEAST... PREFERENCE: GENERAL MODEL COMPROMISE CONFIDENCE: ABOVE AVERAGE THE LATEST MODELS HAVE COME INTO VERY GOOD AGREEMENT WITH THE LARGER SCALE FEATURES ASSOCD WITH THE EJECTING SRN STREAM SHORTWAVE TROUGH AND THE DEVELOPING SFC LOW ALONG THE ARCTIC FRONTAL ZONE SETTLING SOUTH TWD THE SOUTHEAST U.S. ON MON. WILL PREFER A GENERAL MODEL COMPROMISE AT THIS POINT TO RESOLVE ANY LINGER SMALLER SCALE DIFFS. ...UPPER LOW OVER WRN CANADA...GRADUALLY DRIFTING EAST THROUGH MIDWEEK... PREFERENCE: BLEND OF THE 00Z GFS/12Z UKMET/12Z GEM GLOBAL CONFIDENCE: BELOW AVERAGE THE MODELS GRADUALLY TAKE THE NEARLY STATIONARY UPR LOW OVER WRN BRITISH COLUMBIA GRADUALLY EASTWARD OVER THE THE NEXT 2 TO 3 DAYS INTO S CNTRL CANADA. THE 00Z NAM SUGGESTS A NOTABLY DEEPER LOW OVER SASKATCHEWAN AND MANITOBA VS THE GLOBAL MODEL CONSENSUS BY WED AND THU. THE 00Z GFS HAS TRENDED A LITTLE SLOWER AND WEAKER AND HAS BETTER AGREEMENT WITH THE 12Z GEM GLOBAL AND TO SOME EXTENT THE 12Z UKMET. THE 12Z ECMWF IS A BIT FASTER TO ADVANCE THE ENERGY EASTWARD. CONFIDENCE WILL BE LIMITED...BUT GIVEN THE NEARLY STATIONARY NATURE OF THE ENERGY AND THE PRESENCE OF RIDGING STILL TO THE NORTH OF THE UPR LOW...WOULD PREFER A SLOWER SOLN AWAY FROM THE ECMWF AND ALSO THE NAM. WILL PREFER A CONSENSUS OF THE GFS/UKMET AND GEM GLOBAL ATTM. ...WEAK MID LEVEL TROUGH CROSSING THE SRN PLAINS/SOUTHEAST TUE AND WED... PREFERENCE: BLEND OF THE 12Z GFS/ECMWF CONFIDENCE: AVERAGE THE 00Z NAM REMAINS A LITTLE FLATTER WITH THE MID LVL WAVE COMPARED TO THE REMAINING MODELS TUE AS THE ENERGY MOVES THROUGH THE SRN PLAINS AND THIS CONTINUES TO BE THE CASE THROUGH WED AS THE ENERGY CROSSES THE GULF COAST STATES/SOUTHEAST. THE 12Z UKMET ON THE OTHER HAND APPEARS TO BE A LITTLE TOO SHARP. THE 12Z ECMWF/12Z GEM GLOBAL AND 00Z GFS SPLIT THE DIFF...BUT GENERALLY CLUSTER WELL. WILL MAINTAIN CONTINUITY FROM THE PREV SHIFT AND CONTINUE WITH A GFS/ECMWF BLEND. ...STRENGTHENING MID/UPPER LEVEL TROUGH REACHING THE CNTRL/SRN PLAINS/GULF COAST STATES WED AND THU... PREFERENCE: BLEND OF THE 12Z ECMWF/12Z ECENS MEAN CONFIDENCE: AVERAGE THE 00Z NAM HAS TRENDED A LITTLE STRONGER WITH THE HEIGHT FALLS ASSOCD WITH THIS SHORTWAVE ENERGY DIGGING DOWN ACROSS THE CNTRL/SRN PLAINS AND TWD THE GULF COAST STATES WED AND THU. THE 00Z GFS HAS TRENDED A BIT WEAKER COMPARED TO ITS 12Z/SUN RUN...BUT OVERALL THE GFS IS FAIRLY CLOSE TO THE NAM WITH RESPECT TO DEPTH. THE 12Z ECMWF/12Z UKMET AND 12Z GEM GLOBAL ALSO ARE RELATIVELY CLOSE WITH THE TIMING AND DEPTH OF THE TROUGHING RELATIVE TO THE NAM/GFS CAMP. THE 00Z GFS IS SLIGHTLY FASTER THAN THE MULTI-MODEL CONSENSUS AND ACTUALLY THE LATEST GEFS MEAN AND ECENS MEAN TEND TO SUPPORT THE MASS FIELDS OF THE ECMWF. GIVEN SUPPORT FROM THE UKMET/GEM GLOBAL AND GEFS MEAN...WILL FAVOR A SOLN GENERALLY TWD THE ECMWF/ECENS MEAN CLUSTER. ...NRN STREAM MID LEVEL SHORTWAVE AFFECTING THE GREAT LAKES TO THE NORTHEAST ON WED AND THU... PREFERENCE: BLEND OF THE 12Z ECMWF/12Z ECENS MEAN/18Z GEFS MEAN CONFIDENCE: BELOW AVERAGE RUN TO RUN CONSISTENCY REMAINS VERY POOR WITH THIS SYSTEM BY WED OVER THE GREAT LAKES/NORTHEAST WHICH WILL AGAIN LIMIT CONFIDENCE IN THE MODEL CHOICE FOR THIS FEATURE. THE 00Z GFS AND 12Z GEM GLOBAL ARE THE SLOWEST SOLNS...WITH THE 12Z ECMWF THE FASTEST AND THIS INCLUDES THE LATEST ECENS MEAN AS WELL. THE 00Z NAM AND 12Z UKMET SPLIT THE DIFF BUT THE 00Z NAM APPEARS TOO AMPLIFIED. THE LATEST GEFS MEAN TENDS TO SUPPORT THE FASTER ECMWF SOLN AND IS NO WHERE NEAR AS SLOW AS THE DETERMINISTIC GFS. WILL FAVOR THE ECMWF LED CLUSTER WITH THE ENSEMBLE MEANS ATTM. ...SHORTWAVE TROUGH/SURFACE LOW APPROACHING THE PACIFIC NORTHWEST BY THU... PREFERENCE: BLEND OF THE 12Z ECMWF/12Z ECENS MEAN/18Z GEFS MEAN CONFIDENCE: AVERAGE THE MODELS INDICATE A SHORTWAVE TROUGH AND ATTENDANT SFC LOW/FRONT APPROACHING THE PAC NORTHWEST BY EARLY THU. THE 00Z GFS IS A BIT DEEPER THAN THE MULTI-MODEL CONSENSUS. THE LATEST GEFS MEAN AND ECENS MEAN CLUSTER BEST WITH THE 12Z ECMWF. THE 12Z GEM GLOBAL AND 12Z UKMET CLUSTER RELATIVELY WELL WITH THE ECMWF. THE 00Z NAM APPEARS TO BE TOO WEAK OVERALL. WILL PREFER THE ECMWF LED CLUSTER WITH THE ENSEMBLE MEANS. www.wpc.ncep.noaa.gov/html/model2.shtml... ORRISON