EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 235 AM EDT FRI AUG 05 2016 VALID 12Z MON AUG 08 2016 - 12Z FRI AUG 12 2016 ...GUIDANCE/UNCERTAINTY ASSESSMENT AND WEATHER PATTERN HIGHLIGHTS/THREATS... THE WPC MEDIUM RANGE PRODUCT SUITE WAS PRIMARILY DERIVED FROM A COMPOSITE BLEND OF REASONABLY WELL CLUSTERED GUIDANCE FROM THE LATEST GFS/ECMWF AND GEFS/NAEFS/ECMWF ENSEMBLES ALONG WITH WPC CONTINUITY. GUIDANCE REASONABLY AGREES THAT AN UNSETTLING MID-UPPER LEVEL TROUGH WILL AMPLIFY ALONG THE WEST COAST NEXT WEEK TO SUPPORT SOME SUMMER NWRN US SHOWERS...WITH MODEST SWRN US MONSOONAL MOISTURE/ACTIVITY ALSO PULLING UP AHEAD THROUGH THE INTERMOUNTAIN WEST/ROCKIES. A SERIES OF HARDER TO PREDICT EJECTING IMPLUSES RIDING THE UPPER JET DOWNSTREAM OVER A PERSISTENT AND WAVY US NRN TIER STATES FRONTAL ZONE SHOULD MEANWHILE ACT AS A PERIODIC FOCUS FOR LOCALLY HEAVY CONVECTION/MCS ACTIVITY FUELED BY ENHANCED POOLED MOISTURE/INFLOW. WPC MEDIUM RANGE DAYS 4-7 QPF PROGS FOCUS MUCH OF THIS ACTIVITY OVER THE N-CENTRAL US. THIS OCCURS AND SPREADS EASTWARD AS WELL OVERTOP A SW/CENTRAL TO ERN US MID-LATITUDE RIDGE. ABOVE AVERAGE TEMPERATURES SHOULD MAINLY CONTINUE UNDER THE RIDGE...WITH SOME PERIODS OF RELIEF FROM SCATTERED CONVECTION. MEANWHILE...A SIGNIFICANT UPPER-LEVEL LOW IS EXPECTED TO WORK GRADUALLY WESTWARD UNDERNEATH OVER THE SERN US THEN CENTRAL GULF COAST AS A BERMUDA HIGH BUILDS OFFSHORE THE SERN US. THIS SLOW MOVING LOW WOULD INTERACT WITH DEEPENED MOISTURE LINGERING NEAR/SOUTH OF A WEAKENING STALLED FRONT TO SUPPORT A PROLONGED LOCALLY ENHANCED RAINFALL THREAT OVER THE REGION AS ALSO EMPHASIZED WITHIN THE WPC MEDIUM RANGE DAYS 4-7 QPF PROGS. SCHICHTEL