EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1117 AM EST FRI MAR 11 2016 VALID 12Z MON MAR 14 2016 - 12Z FRI MAR 18 2016 ...OVERVIEW... UPPER RIDGING WILL GRADUALLY BUILD INTO THE WEST COAST NEXT WEEK WHILE BROAD TROUGHING CARVES OUT FROM THE ROCKIES TO THE CENTRAL U.S.. WITHIN THE MEAN FLOW...SHORTWAVE ENERGY IS EXPECTED TO LIFT FROM THE TENNESSEE VALLEY TO THE MID-ATLANTIC COAST ON MONDAY...BUT THEN THE FOCUS OF THE FORECAST WILL SHIFT UPSTREAM AS AN UPPER TROUGH PROGRESSING THROUGH THE NORTHWEST EARLY IN THE WEEK ENCOUNTERS A MEAN RIDGE OVER EASTERN CANADA AND CLOSES OFF A POTENTIALLY SLOW MOVING UPPER LOW NEAR THE GREAT LAKES BY THE MIDDLE OF THE WEEK. ...GUIDANCE EVALUATION... DETERMINISTIC GUIDANCE HAS COME INTO BETTER AGREEMENT WITH THE LARGE SCALE EVOLUTION OF THE FLOW OVER THE LOWER 48 NEXT WEEK...BUT ARE STILL SHOWING SOME SIGNIFICANT DIFFERENCES BOTH WITH STRENGTH/LOCATION OF THE UPPER LOW CLOSING OFF NEAR THE GREAT LAKES AND WITH THE AMPLIFICATION OF THE RIDGE IN THE WESTERN U.S.. THE WPC FORECAST WAS LARGELY BASED OFF THE GEFS/ECMWF ENSEMBLE MEANS SINCE A BLEND OF THE TWO OFFERED A GOOD COMPROMISE BETWEEN A MUCH STRONGER GFS/UKMET AND WEAKER ECMWF/CMC CLOSED LOW OVER THE GREAT LAKES...AND THE MEANS ALSO APPEARED TO BE A GOOD MIDDLE GROUND BETWEEN THE SHARPER/MORE AMPLIFIED ECMWF AND BROADER/LESS AMPLIFIED RIDGE BUILDING INTO THE WEST. SLIGHTLY MORE WEIGHT WAS GIVEN TO THE GEFS MEAN...SINCE IT HAS BEEN MORE CONSISTENT THAN THE ECWMF WITH THE EVOLUTION OF THE LOW CLOSING OFF OVER THE GREAT LAKES. GERHARDT ...SENSIBLE WEATHER HIGHLIGHTS... PROGRESSIVELY DRIER IN THE WEST AS RIDGING BUILDS MID-LATE WEEK. CENTRAL/NORTHERN ROCKIES WILL SEE RAIN/SNOW AS A COLD FRONT MOVES THROUGH MON-TUE WITH MODEST AMOUNTS/ACCUMULATIONS. NORTHERN THEN SOUTHERN AREAS OF THE CENTRAL/EASTERN STATES WILL SEE RAIN/SNOW EXPAND EASTWARD AND SOUTHWARD AS THE FRONT SLOWLY BUT STEADILY PROGRESSES ALONG. WITH MILD TEMPERATURES IN THE EAST -- 10-20F ABOVE CLIMO -- SNOW SHOULD BE CONFINED TO THE NORTHERN AND WESTERN SIDE OF ANCHORING SFC LOW. RECORD HIGH MAXIMA AND ESPECIALLY MINIMA ARE QUITE POSSIBLE AHEAD OF THE FRONT. OVERNIGHT LOWS MAY VERY WELL BE ABOVE AVERAGE HIGH TEMPERATURES. PRECIP WILL LIKELY BLOSSOM THROUGH THE GULF STATES LATER IN THE WEEK AS LOWER LEVEL SOUTHERLY FLOW BRINGS IN MORE MOISTURE ATOP THE SLOWING FRONTAL BOUNDARY. FRACASSO