EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1033 AM EST THU MAR 02 2017 VALID 12Z SUN MAR 05 2017 - 12Z THU MAR 09 2017 OVERVIEW/MODEL CHOICES/CONFIDENCE... MODELS ARE IN BETTER AGREEMENT THAN IN RECENT DAYS WITH THE PROGRESSION OF A MODERATELY-AMPLIFIED SHORTWAVE TROUGH AND ASSOCIATED COLD FRONT MOVING FROM THE NORTHWEST TO THE GREAT LAKES DAYS 4-6/SUN-TUE...WITH MULTI-DAY TRENDS LEANING STRONGLY TOWARD THE GFS/GEFS SCENARIO WHICH IS SLOWER AND STRONGER THAN THE ECMWF/ECMWF ENSEMBLE MEAN CAMP. UNCERTAINTY IN THE PATTERN QUICKLY RETURNS TO NORTH AMERICA BY THE END OF THE MEDIUM RANGE PERIOD HOWEVER...WITH THE EVOLUTION OF THE EASTERN PORTION OF THE OMEGA-BLOCK OVER THE NORTH PACIFIC REMAINING UNRESOLVED. TELECONNECTIONS WITH THE POSITIVE MID-LEVEL HEIGHT ANOMALY NEAR THE BERING SEA SUGGESTS NEARLY ZONAL FLOW IS FAVORED ACROSS THE CONUS BY DAYS 6-7/TUE-WED...WHICH IS CLOSEST TO THE ECMWF ENSEMBLE MEAN...AND FURTHEST FROM THE GFS/GEFS CAMP WHICH SUGGEST THAT A SHORTWAVE RIDGE WILL RETURN TO THE NORTHWEST. REGARDING PREFERENCES...THE 06Z GFS IS MOST REPRESENTATIVE OF THE MODEL CONSENSUS THROUGH DAY 4...PARTICULARLY WITH THE LOW PRESSURE SYSTEM AND COLD FRONT MOVING ACROSS THE CENTRAL U.S...WITH CONFIDENCE ABOVE AVERAGE GIVEN RECENTLY GOOD CONTINUITY IN THE GFS AND OTHER MODELS TRENDING TOWARD IT. AFTERWARD...MODEL PREFERENCES SHIFT TOWARD A PREDOMINANT ECMWF ENSEMBLE MEAN BLEND AVERAGED WITH ABOUT 30 PERCENT GEFS MEAN BY DAY 7/WED...TO ACCOUNT FOR THE GROWING MODEL SPREAD. CONFIDENCE IN THE PRECISE STRUCTURE OF THE PATTERN... PARTICULARLY IN THE NORTHWEST...IS LOW BY DAYS 6/7. WEATHER HIGHLIGHTS... THIS ASSOCIATED SPRING-LIKE PATTERN WILL LIKELY BE ACCOMPANIED BY TRANSIENT CONDITIONS...WITH HIGHER ELEVATION SNOWS ACROSS THE NORTHWEST/ROCKIES...AND CONVECTIVE PRECIPITATION WITH A PRECEDING WARM-UP OCCURRING FROM THE MISSISSIPPI VALLEY EASTWARD SUNDAY THROUGH TUESDAY. UNSETTLED CONDITIONS WITH PERIODIC PRECIPITATION MAY RETURN TO THE NORTHWEST NEXT TUESDAY AND WEDNESDAY AS WELL IF THE CURRENT MODEL CHOICES VERIFY. IF THE GFS OR GEFS MEAN VERIFY INSTEAD...DRY AND WARMER CONDITIONS MAY OCCUR...ALTHOUGH THIS POSSIBILITY APPEARS LEAST PROBABLE AT THIS TIME. ELSEWHERE...DRY AND COOLER CONDITIONS WILL FOLLOW BEHIND THE COLD FRONT. JAMES