EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1200 AM EDT THU AUG 14 2014 VALID 12Z SUN AUG 17 2014 - 12Z THU AUG 21 2014 THE ENSEMBLE MEANS CONTINUE TO CONSISTENTLY DEPICT THE MAJOR SYNOPTIC SYSTEMS AFFECTING CENTRAL NORTH AMERICA AT THE MEDIUM RANGE. NONE OF THE OPERATIONAL MODELS--GFS AND ECMWF INCLUDED--HAVE PROVEN CORRELATED SUFFICIENTLY WITH THE MEANS TO MERIT THEIR INCORPORATION INTO THE MANUAL PROGS. THE FLATTENING OF THE PATTERN ACROSS THE UNITED STATES IS STILL THE MAIN MESSAGE THIS PERIOD, WITH A WASHING OUT OF BOTH TEMPERATURE ANOMALIES AND WIDESPREAD RAINFALL. THE BEST BET FOR SIGNIFICANT PRECIPITATION WILL BE ASTRIDE THE POLAR FRONT FROM THE OHIO VALLEY TO THE MID ATLANTIC STATES. THE SOUTHWESTERN MONSOON ALSO RELAXES WITH THE WESTERLIES, WITH A MARKED DROP IN SHOWER ACTIVITY THERE. CISCO