EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1200 PM EDT WED APR 20 2016 VALID 12Z SAT APR 23 2016 - 12Z WED APR 27 2016 ...OVERVIEW... THE OVERALL UPPER-LEVEL PATTERN WILL FAVOR ACTIVE WEATHER IN THE WEST AS MULTIPLE SHORTWAVES/CUTOFF LOWS MOVE INTO A LONGWAVE TROUGH POSITION. THE EAST WILL SEE THE ARRIVAL OF COLDER AIR FROM CANADA AS NORTHWESTERLY FLOW STRENGTHS DUE TO AN UPPER-LEVEL LOW IN SOUTHEASTERN CANADA BEING BLOCKED BY A GREENLAND HIGH. ...GUIDANCE ASSESSMENT AND PREFERENCES... THE MODEL GUIDANCE STARTS OUT WITH A NOTICEABLE DIFFERENCE ALOFT IN THE WEST. THE ECMWF SOLUTIONS DEPICT A DEEPER CUTOFF LOW MOVING FROM THE GREAT BASIN INTO THE CENTRAL ROCKIES DURING THE WEEKEND/DAY 3-4 WHEREAS THE GFS SOLUTIONS HAVE BACKED OFF FROM A CUTOFF SCENARIO TO MORE OF AN OPEN WAVE. THE ECMWF HAS BEEN VERY CONSISTENT IN THE OVERALL STRUCTURE OF THIS UPPER-LEVEL LOW FOR THE PAST FEW RUNS. GIVEN THE LACK OF STABILITY IN THE GFS SOLUTIONS...THE DAY 3 AND 4 WPC BLEND CONSISTS OF MOSTLY THE 00Z ECMWF AND THE 00Z EC MEAN. FURTHER DOWN THROUGH DAY 7/WED...THE MODELS GENERALLY AGREE THAT A COUPLE MORE SHORTWAVE TROUGHS WILL SWING INTO THE WEST. OVER SOUTHEASTERN CANADA...THE ECMWF SHOWS AN ANOMALOUS SHORTWAVE TRYING TO PUSH SOUTH INTO THE GREAT LAKES IN DAYS 6 AND 7. THE WPC BLEND INCLUDES THE 00Z NAEFS FOR DAYS 6 AND 7 TO DAMP OUT THIS FEATURE SEEN ON THE ECMWF SOLUTIONS. ...WEATHER HIGHLIGHTS... TAIL END OF A COLD FRONT SHOULD PROVIDE A FOCUS FOR RAINS OVER S TEXAS THIS WEEKEND BUT THE LARGER AREAL COVERAGE WILL BE ACROSS THE WEST AND NORTHERN TIER WITH THE WEAKENING LEAD UPPER LOW AND THE SLOWLY SINKING COLD FRONT THROUGH THE GREAT LAKES. TEMPERATURES WILL COOL DRAMATICALLY IN THE NORTHERN ROCKIES AND HIGH PLAINS AFTER SATURDAY -- FROM THE 60S/70S AND NEAR 80F TO THE UPPER 40S AND 50S. THE HEAT WILL SHIFT TO THE SOUTHEAST WHERE 80S SHOULD BE WIDESPREAD FROM THE SOUTHERN PLAINS AND EASTWARD. LOW 90S ARE POSSIBLE IN INTERIOR NC/SC/GA (10-15F ABOVE AVERAGE) WHILE 40S ARE LIKELY IN NORTHERN NEW ENGLAND (ABOUT 10F BELOW AVERAGE). SOME SNOW IS NOT OUT OF THE QUESTION ON THE NORTH SIDE OF THE PRECIP SHIELD FROM MI THROUGH NY AND NEW ENGLAND MON-WED. TEMPERATURE GRADIENT WILL BE VERY SHARP N-S ACROSS THE FRONT NEXT WEEK. OCEAN TEMPS IN THE 40S TO NEAR 50F WILL KEEP COASTAL AREAS CHILLY WITH AN ONSHORE FETCH. SECOND SYSTEM COMING OUT OF THE INTERMOUNTAIN WEST EARLY IN THE WEEK SHOULD HELP MORE PRECIP BLOSSOM OVER THE PLAINS MON-WED. SNOW IS LIKELY IN HIGHER ELEVATIONS OF THE WEST WITH THE 700MB ZERO LINE THROUGH CO, NW NM, AND N AZ NEXT WEEK. KONG/FRACASSO