EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 130 AM EDT SUN JUL 31 2016 VALID 12Z WED AUG 03 2016 - 12Z SUN AUG 07 2016 ...OVERVIEW... THE MEDIUM RANGE FORECAST REMAINS RATHER STABLE THROUGH THE PERIOD. THE WESTERLIES WILL LARGELY STAY ALONG/NORTH OF THE US/CANADA BORDER WHILE AN UPPER RIDGE GENERALLY STAYS CENTERED OVER THE SOUTHERN/CENTRAL PLAINS. IN THE TROPICS, THE NATIONAL HURRICANE CENTER CONTINUES TO MONITOR A TROPICAL WAVE POTENTIALLY MOVING INTO THE WESTERN CARIBBEAN BY THE MIDDLE OF NEXT WEEK. PLEASE REFER TO WWW.NHC.NOAA.GOV FOR THE LATEST INFORMATION. ...GUIDANCE ASSESSMENT... ASIDE FROM THE 12Z GFS, WHICH BECAME QUICKER THAN THE CONSENSUS AFTER THURSDAY ESPECIALLY IN CANADA, A BLEND OF THE 18Z GFS/GEFS AND 12Z ECMWF/ECENS MEAN OFFERED A REASONABLE STARTING POINT THROUGH ABOUT NEXT SATURDAY. THIS TAKES A SFC LOW INTO CANADA WITH ITS COLD FRONT MOVING EASTWARD THROUGH THE UPPER MIDWEST AND GREAT LAKES. FRONTAL TIMING HAS BEEN RELATIVELY STABLE THE PAST TWO DAYS WITH A CONSENSUS BLEND. DIFFERENCES START TO BECOME MORE NOTICEABLE BY NEXT WEEKEND WITH THE 12Z ECMWF OVER NW CANADA, WHICH BLEEDS SOUTHWARD INTO THE CONUS. GIVEN ITS DEPARTURE FROM THE ENSEMBLES, TRENDED TOWARD A BLEND OF JUST THE 18Z GFS/GEFS AND 12Z ECENS MEAN. ...SENSIBLE WEATHER HIGHLIGHTS... TEMPERATURES WILL BE NEAR/ABOVE NORMAL AHEAD OF THE PROGRESSIVE FRONT, INITIALLY IN THE UPPER MIDWEST MIDWEEK THEN INTO THE NORTHEAST BY FRIDAY. ONLY MODESTLY COOLER AIR WILL FILTER IN BEHIND IT. COOLER THAN AVERAGE MAX TEMPERATURES WILL BE COMMON IN THE INTERMOUNTAIN WEST THANKS TO SCATTERED SHOWERS/STORMS FED BY MONSOONAL MOISTURE. LOCALIZED HEAVY RAIN WILL BE POSSIBLE IN THE FOUR CORNERS REGION. IN THE SOUTHEAST, THE TAIL END OF AN ATLANTIC FRONT WILL ACT AS A FOCUS FOR SHOWERS/STORMS AND POSSIBLE HEAVY RAIN THROUGH THE PERIOD. FINALLY, WESTWARD MOVING TROPICAL WAVE MAY SPREAD RAIN INTO S TEXAS NEXT WEEKEND, DEPENDING ON ITS TRACK. FRACASSO