EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 139 AM EDT SAT APR 02 2016 VALID 12Z TUE APR 05 2016 - 12Z SAT APR 09 2016 ...RECORD WARMTH LIKELY FOR PORTIONS OF THE WEST NEXT WEEK... ...RECORD COLD LIKELY FOR PORTIONS OF THE EAST ALONG WITH SNOW... VERY LITTLE CHANGE MADE THROUGH DAY 5 --- WITH THE 1/12Z GFS/ECMWF AND THEIR MEANS IN GOOD 'SYNCH' WITH THE TRAJECTORIES OF MODIFIED-ARCTIC AIRMASSES MIGRATIONS ALONG/EAST OF THE CONTINENTAL DIVIDE. THE NATIONAL TEMPERATURE FORECAST SEEMED TO BE ON TRACK FOR WELL BELOW NORMAL TEMPERATURES ACROSS THE GREAT LAKES...NORTHEAST AND EAST CENTRAL STATES --- THE 'BACKDOOR' FRONTS ACROSS THE PLAINS --- AND THE OFFSHORE FLOW EVENT FOR THE WEST COAST. IN RESPONSE TO THE PROJECTED MID-LEVEL CYCLONE TRACK FROM EAST CENTRAL ALBERTA TO NORTHERN NEW ENGLAND THIS FORECAST PERIOD---THE CHALLENGING PART OF THE FORECAST WILL BE TO JUDGE THE IMPACT OF THE 'DRY' FRONTS THAT SPREAD SOUTHWARD ACROSS THE HIGH PLAINS AND DOWNSTREAM INTO THE SOUTHERN PLAINS...OZARKS AND THE SOUTHEAST/GULF COAST. THE VERY DRY AIRMASSES WILL MAKE FOR VERY COOL NIGHTS BUT TEMPERATE DAYS --- AND LARGE DIURNAL TEMPERATURE RANGES. THE ADJUSTMENTS MADE TO THE NEW DAY 6-7 FORECAST---WERE ESSENTIALLY A BY-PRODUCT OF THE BLEND. THE 1/12Z DETERMINISTIC ECMWF WITH THE THREE MEANS --- ECENS/NAEFS AND GEFS --- FOR TEMPERATURES AND PRECIPITATION PROBABILITIES --- ADDS SOME PRECIPITATION CHANCES ACROSS THE SOUTHWEST --- WITH THE MID-LEVEL PATTERN SUGGESTING ISOLATED HIGH-BASED CONVECTION POTENTIAL ON/AFTER DAY 6. AND FOR THE EASTERN SEABOARD...THE 1/12Z GUIDANCE IS DECIDEDLY 'WETTER' WITH THE THURSDAY-FRIDAY 'CLIPPER' MIGRATING ACROSS THE EASTERN GREAT LAKES AND NORTHERN NEW ENGLAND. VOJTESAK .