EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1030 AM EST FRI FEB 24 2017 VALID 12Z MON FEB 27 2017 - 12Z FRI MAR 03 2017 ...OVERVIEW... LARGE TROUGH IN THE WEST WILL CONTINUE TO PROGRESS EASTWARD TOWARD THE CENTRAL PLAINS BY TUESDAY...GREAT LAKES BY WEDNESDAY...AND WILL PUSH OFF THE EAST COAST BY THURSDAY/FRIDAY. HIGH PRESSURE WILL BUILD ACROSS THE WEST BY MIDWEEK AND WILL CONTINUE BUILDING EAST ACROSS THE PLAINS THROUGH THE END OF THE WEEK. ...MODEL EVALUATION/PREFERENCES... ENSEMBLES CONTINUED TO BE IN GOOD AGREEMENT OVER THE MEDIUM RANGE PERIOD WITH SOME NOTABLE DIFFERENCES IN THE OPERATIONAL MODELS. AT THE START OF THE MEDIUM RANGE PERIOD (MONDAY/TUESDAY)...THE TROUGH ACROSS THE WEST WILL BEGIN TO LIFT NORTHEAST WHILE AN UPPER RIDGE SETTLES ACROSS THE SOUTHEASTERN U.S. BY MIDWEEK...THE TROUGH WILL CENTER ACROSS THE CENTRAL PLAINS/UPPER MIDWEST WHILE RIDGING CONTINUES TO BUILD ACROSS THE WEST. BY THE END OF THE WEEK...THE TROUGH WILL MOVE OVER THE EASTERN HALF OF CONUS WITH RIDGING CONTINUING IN THE WEST. THE 00Z GFS CONTINUED TO BE FARTHER SOUTHEAST/FASTER THAN THE 00Z ECMWF WITH THE TROUGH SWINGING ACROSS THE EAST AS THE MAIN COLD FRONT PUSHES OUT TOWARD THE GREAT LAKES TO SOUTHERN PLAINS BY WEDNESDAY. AS THE TROUGH SHIFTS TOWARD THE EAST COAST BY THURSDAY/FRIDAY...THE GFS CONTINUES TO BE ONE OF THE FASTER SOLUTIONS. AN ECMWF/ECENS BASED BLEND WITH CONTINUITY WAS USED WITH SOME GFS ADDED AS THERE WERE ENSEMBLE SOLUTIONS SUGGESTING A FASTER TREND WITH THE TROUGH IN THE EAST COULD BE POSSIBLE. ...WEATHER HIGHLIGHTS/THREATS... WITH THE TROUGH LIFTING FROM THE CENTRAL PLAINS TOWARD THE MISSISSIPPI VALLEY BY MIDWEEK...MODERATE TO LOCAL HEAVY RAINFALL CAN BE EXPECTED ESPECIALLY ACROSS THE MID/LOWER MISSISSIPPI VALLEY. THE POTENTIAL FOR SEVERE WEATHER FOR THIS REGION WILL BE POSSIBLE ESPECIALLY ON WEDNESDAY (CHECK SPC PRODUCTS FOR MORE INFORMATION). AS THE SURFACE LOW LIFTS AND DEEPENS FROM THE PLAINS TO THE GREAT LAKES...SNOW WILL LIKELY DEVELOP ON THE NORTHWEST SIDE OF THE LOW AS IT APPROACHES THE UPPER MIDWEST/GREAT LAKES. ANOTHER SURGE OF WARMER AIR WILL BE IN PLACE ACROSS THE EASTERN U.S. AHEAD OF THE COLD FRONT (+10-15F ABOVE AVERAGE). HOWEVER...ONCE THE FRONT PASSES TEMPERATURES WILL RETURN BACK TO NORMAL VALUES. MOST OF THE WEST COAST...WITH THE EXCEPTION OF THE PACIFIC NORTHWEST/NORTHERN ROCKIES...WILL REMAIN DRY DUE TO HIGH PRESSURE STAYING IN PLACE. REINHART/FRACASSO