EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1223 AM EST WED DEC 31 2014 VALID 12Z SAT JAN 03 2015 - 12Z WED JAN 07 2015 EXCEPT FOR A BRIEF WINDOW OF OPPORTUNITY FOR PHASING EARLY IN THE PERIOD, THE DISTINCT SPLIT FLOW IS FORECAST BY ALL THE GLOBAL NUMERICAL MODELS TO CONTINUE THROUGH THE MEDIUM RANGE. THE DEGREE OF PHASING DAYS 3 AND 4 ACROSS THE GREAT LAKES AND NORTHEAST IS STILL UNCLEAR, WITH SOME MODELS SPINNING UP A GIGANTIC HYBRID LOW OVER THE LAKES AND OTHERS KEEPING THE SHORTWAVES DISTINCT. USED A BLEND OF THE 12Z/30 ECMWF AND ECENS MEAN FOR THE FRONTS AND PRESSURES, REFLECTING AT LEAST A MODEST PHASING. AFTER THAT EVENT, THE STREAMS GO SEPARATE AGAIN, WITH COLD ACROSS THE NORTHERN TIER AND MOSTLY FLAT WAVES RUNNING OUT ACROSS THE SOUTH. CISCO