EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1153 PM EDT FRI MAR 27 2015 VALID 12Z TUE MAR 31 2015 - 12Z SAT APR 04 2015 ...OVERVIEW AND GUIDANCE PREFERENCES... THE TRANSITION TO ZONAL FLOW HAS WREAKED HAVOC WITH THE ENSEMBLES... AS CAN BE THE CASE. LOW AMPLITUDE WAVES SHOULD DOMINATE THE PERIOD AS THE PERSISTENT EASTERN TROUGHING MAY ABATE FOR PERHAPS A COUPLE DAYS NEXT THU-FRI. IT IS DIFFICULT TO ANY DETERMINISTIC MODEL OVER ANOTHER SINCE ALL FALL WITHIN THE MULTI-CENTER ENSEMBLE SPREAD. NEVERTHELESS... THE ECMWF HAS BEEN MORE CONSISTENT WITH SOME -- NOT ALL -- FEATURES ACROSS THE CONUS THAN THE GFS AND HAS MORE SUPPORT FROM THE CMC/UKMET. NOTHING SHOWS GOOD MULTI-DAY CONTINUITY AND THE TREND HAS BEEN BOTH SLOWER AND QUICKER... DEPENDING ON THE SYSTEM OF INTEREST. OPTED TO BLEND THE 12Z ECMWF/ECENS MEAN TUE-WED IN RESPONSE TO A SFC WAVE MOVING ALONG 40N OFF THE EAST COAST THAT HAS BETTER SUPPORT FOR SOMETHING MORE DEFINED /ECMWF/ THAN LESS DEFINED /GFS/. FOR THU-SAT... TRENDED TOWARD A SPLIT BETWEEN THE 12Z NAEFS AND ECENS MEANS AS THE RECENT GEFS MEANS WERE MUCH QUICKER TO BRING IN THE NEXT SHORTWAVE INTO THE PAC NW ON SAT 4/4. BEST OVERLAPPING ENSEMBLE SUPPORT AMONG ALL THREE ENSEMBLE SYSTEMS -- ECMWF/GEFS/CANADIAN -- LIES IN THE MODESTLY SLOWER CAMP. BUT... THE CAVEAT REMAINS TIMING DIFFERENCES/INCONSISTENCIES AND WOULD NOT BE SURPRISED IF THIS CHANGES IN SUCCESSIVE RUNS. COURSE OF LEAST REGRET LIES AWAY FROM EXTREME SOLUTIONS IN QUASI-ZONAL FLOW. ...SENSIBLE WEATHER HIGHLIGHTS... WARM TEMPERATURES WILL TRAVEL EASTWARD AHEAD OF THE MAIN SYSTEM INITIALLY IN THE INTERIOR NW ON TUESDAY. TEMPS 10-20F ABOVE AVG WILL BE COMMON AHEAD OF THE COLD FRONT AND ABOUT 5-15F BELOW AVG IN ITS WAKE. PRECIPITATION WILL FOCUS NEAR THE FRONT AND EASTWARD LEAD SYSTEM AS WELL AS IN THE SOUTH WHERE SOME MODELS/ENSEMBLES SHOW SE TEXAS RECEIVING A COUPLE INCHES OF RAIN. ENSEMBLES ARE EXPECTEDLY LESS BULLISH BUT THE POTENTIAL DOES EXIST FOR AT LEAST MODEST RAIN. MORE WIDESPREAD AND PERHAPS HEAVIER PRECIP MAY EXPAND THROUGH THE OHIO VALLEY AND INTO THE NORTHEAST/MID-ATLANTIC AHEAD OF THE PROGRESSIVE SFC FRONT NEXT FRIDAY. FRACASSO