MODEL DIAGNOSTIC DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1133 AM EST WED FEB 25 2015 VALID FEB 25/1200 UTC THRU MAR 01/0000 UTC ...SEE NOUS42 KWNO (ADMNFD) FOR THE STATUS OF THE UPPER AIR INGEST... 12Z MODEL EVALUATION...INCLUDING THE NAM AND GFS ...SHORTWAVE TROUGH TRACKING FROM THE LOWER MS VALLEY TO THE MID-ATLANTIC... ...SURFACE LOW TRACKING FROM THE GULF OF MEXICO TO OFFSHORE THE MID-ATLANTIC... PREFERENCE: BLEND OF THE 12Z GFS/00Z ECMWF AND 00Z UKMET CONFIDENCE: AVERAGE THERE HAS BEEN A SUBTLE TREND IN THE 12Z NAM AND 12Z GFS TO HANG ON TO A SLIGHTLY STRONGER SHORTWAVE EJECTING ACROSS THE GULF COAST STATES AND THEN LIFTING NORTHEAST ACROSS THE MID-ATLANTIC REGION THROUGH EARLY THURS. THE ENERGY WILL BE GRADUALLY SHEAR OUT AS IT ENCOUNTERS DEEPER LAYER CONFLUENT FLOW DOWNSTREAM...BUT THE LATEST TRENDS WOULD TEND TO FAVOR A SLIGHTLY STRONGER LOW CENTER LIFTING NORTHEAST OUT OF THE GULF OF MEXICO LATER TODAY AND THEN OFF THE SOUTHEAST AND MID-ATLANTIC COASTS TONIGHT THROUGH EARLY THURS. THE 12Z NAM AND 09Z SREF MEAN ARE STILL OVERALL A TAD LEFT OF THE MULTI-MODEL CONSENSUS WHICH IS BEST REFLECTED BY THE 12Z GFS/00Z ECMWF AND 00Z UKMET. THE GFS THOUGH IS A BIT MORE PROGRESSIVE THAN ECMWF AND UKMET. THE 00Z GEM IS A TAD MORE SUPPRESSED AND GRADUALLY THE FASTEST SOLUTION. THE 06Z GEFS MEAN AND 00Z ECENS MEAN STRONGLY FAVOR THE MULTI-MODEL CONSENSUS AS LED BY THE GFS/ECMWF AND UKMET SOLUTIONS...AND SO THIS WILL BE THE PREFERENCE. ...STRENGTHENING TROUGHING OVER THE GREAT LAKES/NORTHEAST THROUGH FRI... PREFERENCE: NON-UKMET CONSENSUS CONFIDENCE: ABOVE AVERAGE THE 00Z UKMET GRADUALLY BECOMES A BIT STRONGER THAN THE MULTI-MODEL CONSENSUS AS THE ENERGY REACHES THE NORTHEAST ON FRI. WILL PREFER A NON-UKMET CONSENSUS AS THE REMAINING MODELS ARE WELL CLUSTERED. ...UPPER TROUGH AMPLIFYING OVER THE WEST FRI INTO SAT... ...LOW PRESSURE OVER THE GREAT BASIN... PREFERENCE: BLEND OF THE 12Z GFS/00Z GEM AND 00Z ECMWF...OR 00Z ECENS MEAN CONFIDENCE: BELOW AVERAGE THE ENSEMBLE SPREAD REMAINS LARGE WITH AN UPPER TROUGH FORECAST TO AMPLIFY ACROSS THE WEST LATER THIS WEEK...BUT THE INDIVIDUAL ENSEMBLE MEMBERS HAVE TRENDED AWAY FROM THE STRONGER UKMET SINCE YESTERDAY. THE STRONGER DETERMINISTIC CLUSTERING/CONSENSUS INVOLVES THE 00Z GEM/00Z ECMWF AND 12Z GFS. THE 00Z UKMET IS STILL TOO DEEP IT APPEARS...AND THE 12Z NAM IS A LITTLE WEAKER. THE 00Z ECENS MEAN STRONGLY CLUSTERS WITH THE GEM/ECMWF AND GFS CAMP...WITH THE GEFS MEAN SUGGESTING A SOMEWHAT WEAKER EVOLUTION AND EVEN WEAKER THAN THE NAM. WILL LEAN TOWARD THE STRONGER CONSENSUS...BUT CONFIDENCE REMAINS LIMITED. www.wpc.ncep.noaa.gov/html/model2.shtml... www.wpc.ncep.noaa.gov/h5pref/h5pref.shtml... ORRISON