EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1125 AM EDT SUN JUN 15 2014 VALID 12Z WED JUN 18 2014 - 12Z SUN JUN 22 2014 ...OVERVIEW AND GUIDANCE EVALUATION/PREFERENCES... POTENT ENERGY CONTAINED WITHIN AN AMPLIFIED WRN CONUS TROUGH/CLOSED LOW WED WILL MOVE LATER WEEK INTO AN EVOLVING LARGE SCALE MEAN RIDGE BETWEEN ONE TROUGH SETTLING OVER THE ERN PAC/WEST COAST AND ANOTHER OVER ERN CANADA/NERN CONUS. BY NEXT WEEKEND THIS ENERGY BRINGS SOME DEGREE OF TROUGHING INTO THE E-CENTRAL CONUS AS HEIGHTS ALOFT RISE OVER THE W-CENTRAL CONUS. THE ULTIMATE EVOLUTION OF THIS INITIAL WRN ENERGY WILL LIKELY PROVIDE THE GREATEST UNCERTAINTY WED-SUN AS GUIDANCE SPREAD ILLUSTRATES THE TYPICAL DIFFICULTY IN RESOLVING DETAILS OF ENERGY HEADING INTO A MEAN RIDGE POSITION. STRENGTH EMPHASIS AND TRACK/TIMING HAVE EXHIBITED ENOUGH SPREAD AND RUN VARIABILITY THUS FAR TO KEEP CONFIDENCE INSUFFICIENT FOR USE IN A DETERMINISTIC FCST...FAVORING A 50/50 BLEND OF THE REASONABLY COMPATABLE 00 UTC NAEFS (GFS/CANADIAN ENSEMBLE COMBO) AND 00 UTC ECMWF ENSEMBLE MEAN AS THE STARTING POINT FOR THE DAYS 3-7 FORECAST ALONG WITH SOME MANUALLY APPLIED ADJUSTMENTS TO PROVIDE MAX CONTINUITY AND SOMEWHAT BETTER DEFINED FEATURES CONSISTENT WITH PREDICTABILITY. ...SENSIBLE WEATHER HIGHLIGHTS... HEAVIEST RNFL DURING THE FCST PERIOD SHOULD FOCUS NEAR THE NRN PLAINS/UPPER MS VALLEY AND GREAT LAKES/MIDWEST IN ASSOCIATION WITH THE EJECTING WRN CONUS ENERGY AND CENTRAL US LOW PRESSURE/LEAD MOIST FLOW CONVERGENCE WHOSE EWD OR NEWD PROGRESSION MAY BE ON THE SLOW SIDE. ALSO EXPECT CONVECTION TO EXTEND EWD/SEWD TO THE EAST COAST WITH SOME FOCUS ALONG A FRONTAL ZONE DROPPING FROM THE NORTHEAST INTO THE MID ATLANTIC AND EXTENDING BACK TO THE CENTRAL US SYSTEM. ON A SOMEWHAT LESS INTENSE/WIDESPREAD/FREQUENT BASIS SOME CONVECTION IS POSSIBLE OVER PARTS OF THE CENTRAL-SRN PLAINS AND SOUTHEAST. THE MOST PRONOUNCED HEAT OVER THE ERN HALF OF THE COUNTRY SHOULD BE OVER THE CAROLINAS/SRN MID ATLANTIC WITH MULTIPLE DAYS OF HIGHS AT LEAST 5-10F ABOVE NORMAL. VERY WARM TO HOT CONDS WILL ALSO EXTEND BACK TO THE MIDWEST FOR A PORTION OF THE PERIOD BUT WITH SLIGHTLY LESSER ANOMALIES. ON THE OTHER HAND THE NRN ROCKIES/HIGH PLAINS SHOULD SEE HIGHS 10-20F BELOW NORMAL ON WED FOLLOWED BY A WARMING TREND. SCHICHTEL