EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1142 AM EST TUE MAR 01 2016 VALID 12Z FRI MAR 04 2016 - 12Z TUE MAR 08 2016 ...GENERAL FLOW PATTERN... PROGRESSIVE FLOW OVER THE LOWER 48 LATE THIS WEEK WILL FEATURE A SURFACE LOW SPINNING UP OFF THE CAROLINA COAST EARLY FRIDAY FOLLOWED BY AN UPSTREAM CLIPPER SYSTEM STREAKING FROM THE UPPER MIDWEST TO THE MID-ATLANTIC REGION THIS WEEKEND. STARTING EARLY NEXT WEEK...THE PATTERN SHOULD BECOME QUITE AMPLIFIED ACROSS THE CONUS AS ANOMALOUS TROUGHING DIGS INTO WESTERN U.S. WHILE AN EXPANSIVE RIDGE BUILDS IN OVER THE EASTERN TWO THIRDS OF THE NATION. ...MODEL EVALUATION/PREFERENCES... MODELS HAVE COME INTO MUCH BETTER AGREEMENT WITH THE SURFACE LOW DEEPENING OFF THE CAROLINA COAST EARLY FRIDAY. THERE ARE STILL DETAIL DIFFERENCES TO BE RESOLVED WITH THE EXACT DEPTH AND TIMING...ESPECIALLY AS IT LIFTS TOWARDS THE CANADIAN MARITIMES FRIDAY NIGHT. ALSO...THERE ARE STILL SLIGHT TIMING/STRENGTH DIFFERENCES WITH THE CLIPPER SYSTEM DROPPING OUT OF THE UPPER MIDWEST THIS WEEKEND. A BLEND OF THE ECWMF/ECMWF ENSEMBLE MEAN/GEFS MEAN SEEMED TO BEST REPRESENT THE MIDDLE OF MODEL SPREAD WITH BOTH THESE SYSTEMS. LATER IN THE FORECAST PERIOD...DETERMINISTIC GUIDANCE AND ENSEMBLE MEANS HAVE BEEN CONSISTENT WITH ADVERTISING A TRANSITION TOWARDS MORE AMPLIFIED FLOW OVER THE CONUS EARLY NEXT WEEK. HOWEVER...MODELS ARE STILL SHOWING VARYING SOLUTIONS WITH THE EXACT EVOLUTION OF THE UPPER TROUGH DIGGING INTO THE WEST AND RIDGE BUILDING IN OVER THE EAST. THE GENERAL TREND HAS BEEN TOWARDS PROGRESSING HEIGHT FALLS FARTHER EAST INTO THE INTERMOUNTAIN WEST AND EVENTUALLY GREAT PLAINS...SO THE FORECAST WAS LARGELY BASED OFF THE ECWMF ENSEMBLE MEAN BY THE END OF THE FORECAST PERIOD SINCE IT WAS ON THE EASTERN SIDE OF MODEL SPREAD. ...SENSIBLE WEATHER HIGHLIGHTS... THE SURFACE LOW DEEPENING OFF THE CAROLINA COAST COULD CLIP PORTIONS OF THE MID-ATLANTIC REGION WITH SNOW BEFORE IT RACES TOWARDS THE CANADIAN MARITIMES ON FRIDAY...PLEASE SEE THE QPFHSD FOR MORE DETAILS ON THE SNOW POTENTIAL WITH THIS SYSTEM. SNOW WILL ALSO BE POSSIBLE WITH THE CLIPPER SYSTEM STREAKING FROM THE UPPER MIDWEST TO THE MID-ATLANTIC...WITH THE BEST CHANCE OF ACCUMULATIONS EXPECTED OVER MINNESOTA AND WISCONSIN. BEHIND THESE SYSTEMS...TEMPERATURES WILL SURGE WELL ABOVE BENEATH A RIDGE EXPANDING OVER THE EASTERN TWO THIRDS OF THE NATION. ALSO...CHANCES FOR HEAVY PRECIPITATION WILL INCREASE OVER THE SOUTHERN/CENTRAL PLAINS AND MISSISSIPPI VALLEY AS GULF MOISTURE FUNNELS NORTHWARD AHEAD OF THE UPPER TROUGH DIGGING INTO THE WEST. MEANWHILE...AN ACTIVE AND WET PERIOD WILL CONTINUE OVER MUCH OF THE WESTERN U.S. THIS WEEKEND AND INTO EARLY NEXT WEEK AS ANOMALOUS TROUGHING DIGS IN OVER THE REGION. GERHARDT