EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1159 AM EDT MON AUG 10 2015 VALID 12Z THU AUG 13 2015 - 12Z MON AUG 17 2015 ...OVERVIEW AND GUIDANCE EVALUATION... WPC CONTINUITY IS WELL MAINTAINED AND THE FCST REMAINS ON TRACK WITH THE GENERAL EVOLUTION OF FLOW FROM LATE THIS WEEK INTO THE WEEKEND WITH WEAKENING OF INITIAL TROUGHS ON EITHER SIDE OF A STRONG/HOT SRN ROCKIES/FOUR CORNERS RIDGE. SOME EMBEDDED DETAILS REMAIN IN DOUBT THOUGH. DEVELOPING SPREAD WITH NRN PAC EVOLUTION...INCLUDING THE SFC REFLECTION THAT REMAINS FROM WEST PAC TROPICAL CYCLONE MOLAVE BEGINS TO PLAY A ROLE IN THE FCST OF HOW MUCH TROUGHING MAY RELOAD NEAR THE PAC NW COAST EARLY NEXT WEEK. FOR MULTIPLE DAYS MODEL AND ENSEMBLE GUIDANCE HAS BEEN SHOWING RAPIDLY INCREASING SPREAD FOR UPSTREAM NRN PAC FLOW THUS IMPACTING THE FCST OVER AT LEAST THE NWRN STATES AND SWRN CANADA LATER IN THE PERIOD WITH SOME PSBL INFLUENCE ON THE AFOREMENTIONED SYSTEM AS WELL. THE ECMWF MEAN REMAINS ON THE LESS AMPLIFIED SIDE OF THE SPREAD FOR TROUGHING NEAR THE PAC NW COAST BY DAY 6/7 SUN/MON. PERHAPS THIS IS PARTIALLY DUE TO THE ECMWF MEAN BECOMING RELATIVELY WEAK/SLOW FOR THE SFC SYS ASSOC WITH WEST PAC TROPICAL CYCLONE MOLAVE UNDERNEATH A MORE DOMINANT NRN STREAM FLOW INTO THE BERING SEA/AK. IT IS STILL QUITE UNCERTAIN HOW THIS SYS MAY INTERACT WITH A NRN STREAM TROUGH...BUT IN SOME FASHION THE MAJORITY OF GUIDANCE GENERALLY SUGGESTS MORE RIDGING WILL DEVELOP DOWNSTREAM OVER THE NERN PAC AND IN TURN SUPPORT DECENT TROUGHING NEAR THE PAC NW. THIS MAY ULTIMATELY FAVOR MORE OF A NON-ECMWF MEAN CONSENSUS...BUT A LESS AMPLIFIED TREND FROM THE 06 UTC GEFS VS THE 00 UTC GEFS MAY BEST FAVOR THE MORE RUN TO RUN CONSISTENT 00 UTC NAEFS. OVERALL...FOR THE LOWER 48 AND SRN CANADA REASONABLE CLUSTERING OF GUIDANCE EXTENDS INTO DAY 5 SATURDAY. LATER INTO DAYS 6/7...THE 00 UTC NAEFS ENSEMBLE MEAN SEEMS TO CONTINUE TO PROVIDES MAX CONTINUITY AND INTERMEDIATE EVOLUTION. ...SENSIBLE WEATHER HIGHLIGHTS... THE WAVY FRONT SETTLING OFF THE GULF/SERN COASTS AND OVER FLORIDA SHOULD PROVIDE A MULTI-DAY FOCUS FOR LOCALLY HVY RNFL WITH BEST POTENTIAL OVER FL. THE UPR LOW FCST TO CLOSE OFF AND RETROGRADE ALONG THE GULF COAST SAT-MON MAY SUPPORT A WWD MIGRATION OF CONVECTION IN THAT TIME FRAME. MEANWHILE A FRONT PROGRESSING FROM THE NRN PLAINS INTO THE NORTHEAST THU-SAT WILL LIKELY GENERATE SHWRS/TSTMS OF VARYING INTENSITY. FARTHER WWD STILL EXPECT THE UPR LOW EJECTING FROM OFF THE WEST COAST TO SUPPORT AN EPISODE OF CONVECTION OVER THE EXTREME NORTHWEST LATE THIS WEEK. AS ASSOC LOW PRES TRACKS ACROSS CANADA THROUGH THE WEEKEND THE TRAILING COLD FRONT SHOULD BRING CONVECTION TO PARTS OF THE NRN TIER. POTENTIAL REMAINS FOR SOME ENHANCEMENT OF NRN TIER RNFL IF THERE IS A SUFFICIENT CONNECTION WITH MONSOONAL MSTR INITIALLY OVER THE FOUR CORNERS STATES. THE LATTER REGION MAY SEE SOME LOCALLY HVY TOTALS. WARMEST TEMPS VERSUS NORMAL SHOULD BE ACROSS THE NRN TIER JUST AHEAD OF THE FRONT EMERGING INTO THE NRN PLAINS FRI-SAT...WITH SOME PLUS 10-15F ANOMALIES FOR HIGHS. ERN STATES WILL SEE A TREND FROM MODESTLY BELOW NORMAL THU TOWARD NEAR/ABOVE NORMAL READINGS WHILE THE RIDGE ALOFT SHOULD KEEP TEMPS ABOVE NORMAL FROM THE SRN HIGH PLAINS INTO THE SOUTHWEST WHERE RECORD TEMPS ARE POSSIBLE. SYSTEM BRUSHING THE NORTHWEST WILL BRING A BRIEF PERIOD OF COOLER TEMPS TO THAT REGION LATE WEEK. SCHICHTEL