EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1238 AM EST SUN JAN 12 2014 VALID 12Z WED JAN 15 2014 - 12Z SUN JAN 19 2014 ...OVERVIEW AND PREFERENCES... THE MODELS/ENSEMBLES SHOW PERSISTENT CYCLONIC FLOW ACROSS THE BERING SEA. TELECONNECTIONS OF THE PERSISTENT FEATURE LEAD TO A MEAN 500 MB RIDGE OVER THE NORTHWEST US AND SOUTHWEST CANADA AND DOWNSTREAM EASTERN US TROUGH. MODELS AND ENSEMBLES SHOW GOOD AGREEMENT WITH THE SUGGESTED TELECONNECTION PATTERN. FROM DAY 3 WED INTO DAY 5 FRI 17 JAN A BLEND OF THE 12Z ECMWF WITH THE 12Z ECMWF MEAN WAS USED TO HANDLE THE WAVE DEVELOPMENT OVER THE MID ATLANTIC TO NORTHEAST. FOR DAYS 5 FRI TO DAY 7 SUN A BLEND OF THE 12Z ECMWF ENSEMBLE MEAN/12Z NAEFS ENSEMBLE MEAN/18Z GEFS MEAN WAS USED. GOOD AGREEMENT EXISTED IN THE 500 MB WAVE PATTERN WITH ONLY MINOR TIMING/AMPLITUDE DIFFERENCES AMONG THE ECMWF ENSEMBLE MEAN WITH THE 12-18Z NAEFS MEAN AND 18Z GEFS MEAN. THIS LENDS ITSELF TO A CONSENSUS APPROACH. THE PRIMARY FCST PROBLEM DURING WED-THU INVOLVES SHRTWV ENERGY CROSSING THE APPALACHIANS AND GREAT LAKES APPROACHING THE EAST COAST. THE 12-18Z GFS AND 18Z GEFS MEAN ARE FASTER THAN THE 12Z ECMWF/ECMWF ENSEMBLE MEAN IN MOVING THE MID LEVEL WAVE AND SFC REFLECTION OFF THE EAST COAST. THE MODELS/ENSEMBLES SHOW AN AMPLIFIED CENTRAL PACIFIC RIDGE/POSSIBLE CLOSED HIGH...WHICH USUALLY BLOCKS EAST FORWARD MOTION OF TROUGHS APPROACHING THE EAST COAST. CONSEQUENTLY...A BLEND OF THE SLOWER ECMWF/ECMWF ENSEMBLE MEAN WERE USED. AGREEMENT IS MUCH BETTER WITH THE DEEP SYSTEM EXPECTED TO MOVE NORTH OF LAKE SUPERIOR THU AND ACROSS ONTARIO INTO QUEBEC FRI 17 JAN. DIFFERENCES MAGNIFY AS THE SYSTEM CROSSES NEW ENGLAND INTO THE CANADIAN MARITIMES...WITH A SPLIT IN THE GFS/ECMWF FCSTS LEADING TO A MEAN PREFERENCE. LIKEWISE...ON SUN 19 JAN THE 12Z ECMWF WAS DEEPER WITH ITS NEXT LOW MOVING NORTH OF THE GREAT LAKES TOWARDS THE ST LAWRENCE VALLEY/NORTHERN NEW ENGLAND. ON THE OTHER SIDE OF THE MAP...THE 18Z GFS WAS FURTHER EAST WITH THE CYCLONE DEVELOPMENT IN THE EAST PACIFIC. THE HIGH AMPLITUDE RIDGE IN THE WEST WOULD FAVOR KEEPING AREAS OF LOW PRESSURE FURTHER WEST...LIKE THE MEAN SOLUTIONS. ...SENSIBLE WEATHER HIGHLIGHTS... EXPECT MOST OF THE WEST TO BE WARM AND DRY UNDER THE INFLUENCE OF THE RIDGE ALOFT...WITH HIGH TEMPS IN CA/NV COMMONLY 10-15 DEGREES F ABOVE NORMAL. HIGHS MAY BE AS MUCH AS 20-30 F ABOVE NORMAL OVER THE NRN PLAINS ON DAY 3 WED. ON THE FLIP SIDE...THE PERSISTENCE OF THE AMPLIFIED TROUGH IN THE SOUTHEAST LEADS TO BELOW NORMAL TEMPS MOST DAYS ACROSS THE SOUTHEAST AND FL...WITH THE DAY 4 TEMPS 15 TO 20 DEGREES BELOW NORMAL ACROSS CENTRAL AND SOUTH PENINSULAR FL. THE MEAN TROUGH AND DIABATICALLY INDUCED LOW PRESSURE FAVORS SEVERAL ROUNDS OF LAKE ENHANCED AND LAKE EFFECT PRECIPITATION/SNOW AROUND THE GREAT LAKES...AND IN THE MID ATLANTIC TO NORTHEAST WITH THE WAVE DEVELOPING ON THE FRONT AND MOVING ACROSS THE REGION WED 15 JAN. PETERSEN