EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 145 AM EDT TUE APR 08 2014 VALID 12Z FRI APR 11 2014 - 12Z TUE APR 15 2014 ...OVERVIEW... AFTER A BRIEF RESPITE IN THE SHORT TERM AND START OF THE MEDIUM RANGE PERIOD... THE GUIDANCE SUGGESTS ANOTHER ROUND OF ACTIVE SPRING-TIME WEATHER FOR THE CENTRAL/EASTERN STATES NEXT WEEKEND INTO EARLY NEXT WEEK. UPPER RIDGING IS FORECAST TO RE-ESTABLISH ITSELF OVER THE GULF OF ALASKA BY SAT/D4 AND EASE NORTHEASTWARD INTO NW CANADA BY TUE/D7. THIS SHOULD ALLOW TROUGHING TO DIG INTO THE CENTRAL THEN EASTERN STATES... SUPPORTING AN ENERGETIC SYSTEM ON THE BOUNDARY BETWEEN LATE-WINTER AND EARLY-SUMMER AIRMASSES. ...GUIDANCE EVALUATION... THE GEFS ENSEMBLE MEMBERS HAVE BEEN ON THE QUICKER SIDE OF THE MULTI-CENTER ENSEMBLE SPREAD OVER THE PAST SEVERAL DAYS AT A D5-7 LEAD TIME AND HAS GENERALLY TRENDED BACK TOWARD A SLOWER SOLUTION IN THE D3-4 LEAD TIME NEARER TO THE GENERALLY MORE STABLE ECMWF ENSEMBLE MEAN SOLUTION. THE OPERATIONAL ECMWF HAS TENDED TO BE ON THE EVEN MORE SLOWER/AMPLIFIED SIDE OF THE SPREAD AT LONGER LEAD TIMES BUT GENERALLY HAS TRENDED BACK TOWARD ITS MEAN. THE OPERATIONAL GFS RUNS HAVE WAVERED BETWEEN THE QUICKER GEFS MEAN RUNS AND SLOWER ECENS MEANS RUNS WHILE THE CANADIAN HAS MOSTLY FAVORED THE ECMWF ENSEMBLE MEAN PACE... BUT IN ITS OWN FLAVOR. THESE GENERALIZATIONS HAVE HELD TRUE WITH THE INCOMING SOUTHERN STREAM CLOSED LOW INTO CALIFORNIA SAT/D4 AS WELL AS THE PHASING CENTRAL/EASTERN CONUS TROUGH EXPECTED EARLY NEXT WEEK. THE ENSEMBLES SHOW THEIR GREATEST INCREASE IN SPREAD OVER THE INTERIOR WEST SUN/D5 AS MANY ECMWF MEMBERS HAVE JUMPED ONTO A SHARPER/SLOWER SOLUTION... WHICH WOULD SLOW DOWN THE NEXT PAC NW SYSTEM BY MON-TUE/D6-7. TO THE SOUTH... THE GEFS IS JUST AHEAD OF THE ECMWF ENSEMBLE MEMBERS WITH THE WEAKENING MID-LEVEL FEATURE BUT IS CARRIED ALONG BY THE QUICKER NORTHERN STREAM ENERGY COMPARED TO THE SLOWER ECMWF-LED CLUSTER. FELT IT WAS PRUDENT TO STAY WITH THE ONGOING PREFERENCE... A MULTI-MODEL BLEND EARLY TRANSITIONING TOWARD THE ECMWF ENSEMBLE MEAN BY TUE/D7. FAVORED DETAILS FROM THE ECMWF OVER THE GFS FRI-MON/D3-6. ...SENSIBLE WEATHER HIGHLIGHTS... TEMPERATURES WILL BE GENERALLY NEAR TO ABOVE AVERAGE ON BOTH THE WEST/EAST COASTS WITH COOLER THAN AVERAGE TEMPERATURES EAST OF THE DIVIDE TOWARD THE GREAT LAKES AND MS VALLEY. COALESCING SYSTEM IN THE CENTRAL STATES WILL BRING A VARIETY OF WEATHER... TYPICAL OF SPRING SYSTEMS... WITH WINTRY CONDITIONS TO ITS NW AND WIDESPREAD MODEST RAINS ALONG AND SE OF THE FRONT... POSSIBLE HEAVY... AS PW VALUES RISE TO +2 STD DEV /OR MORE/ ABOVE CLIMO. COOLER AIR ON THE BACK SIDE OF THIS SYSTEM WILL DROP THROUGH THE PLAINS EARLY NEXT WEEK. TEMPERATURES MAY BE 10-20F BELOW AVERAGE. FRACASSO