EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 251 AM EDT THU JUN 09 2016 VALID 12Z SUN JUN 12 2016 - 12Z THU JUN 16 2016 ...PATTERN OVERVIEW... AMPLIFIED MID-LATITUDE FLOW WILL CONTINUE TO DOMINATE THE PATTERN WITH A PAIR OF ANOMALOUS UPPER LOWS INHABITING THE NORTHEAST PACIFIC AND COASTAL NEW ENGLAND...RESPECTIVELY. PERSISTENT RIDGING ACROSS THE CENTER OF THE CONUS WILL GRADUALLY MOVE EASTWARD TOWARD THE MS RIVER VALLEY BY EARLY NEXT WEEK. THIS OCCURS AS A SOUTHERN STREAM SHORTWAVE MIGRATES FROM THE DESERT SOUTHWEST INTO THE CENTRAL PLAINS BY TUESDAY. EVENTUALLY THIS FEATURE SHOULD APPEAR SOMEWHERE IN THE VICINITY OF THE MIDDLE MS VALLEY/UPPER GREAT LAKES BY DAY 7/JUNE 16 WITHIN BROAD SCALE HEIGHT RISES. ...MODEL EVALUATION/PREFERENCES... CONCLUDING THIS WEEKEND...MODELS HAVE BEEN PLAGUED BY ISSUES WHILE RESOLVING A PAIR OF FEATURES ON THE MAP. FIRST...LONGWAVE TROUGHING OVER THE WEST COAST CONSISTS OF TWO PRIMARY CAMPS...THE ECMWF/UKMET SOLUTION VERSUS THE SLOWER GFS/CMC FORECASTS. WHILE DIFFERENT IN NATURE...BOTH HAVE BEEN RATHER CONSISTENT IN THEIR OWN RIGHT. THE MORE PROGRESSIVE RUNS OF THE ECMWF/UKMET FAVOR SLIDING HEIGHT FALLS INTO THE NORTHERN ROCKIES BY SUNDAY MORNING WHILE ALSO EMPHASIZING A STRONGER SOUTHERN STREAM ACROSS THE DESERT SOUTHWEST. MEANWHILE...RECENT RUNS OF THE GFS HAVE BEEN SLOWER AND MORE DEVELOPED DURING THE DAY 3-5 PERIOD ACROSS THE NORTHERN ROCKIES/PLAINS WITH LESS EMPHASIS ON THE MORE SOUTHERN SHORTWAVE. ADDITIONAL UNCERTAINTIES EXTEND TO A DYNAMIC NORTHEASTERN U.S. SYSTEM...PARTICULARLY DURING THE PROCESS OF LIFTING THE NEGATIVE HEIGHT ANOMALY AWAY FROM THE CONUS. ALL SOLUTIONS AGREE ON A RAPID DEEPENING PROCESS BUT VARY IN HOW LONG IT AFFECTS THE NORTHEASTERN U.S. THE 12Z ENSEMBLE LOW PLOTS SHOW THE SLOWER/SOUTHWARD GEFS MEMBERS ARE IN STARK CONTRAST WITH THE 12Z ECMWF ENSEMBLES. WHILE VARIABLE IN NATURE...A VAST MAJORITY OF THE 12Z CMC MEMBERS ARE CLOSER TO THE FASTER SIDE OF THE GUIDANCE. WHILE MODEL SPREAD DOMINATES THE NORTHEASTERN U.S. INTO THE CANADIAN MARITIMES...THERE IS SUFFICIENT AGREEMENT WITH THE NEXT UPPER LOW DROPPING DOWN FROM THE NORTHEAST PACIFIC DURING THE TUESDAY-THURSDAY TIMEFRAME NEXT WEEK. THE MEDIUM RANGE PRODUCTS DID NOT INCORPORATE ANY OF THE GFS SUITE GIVEN THE SOUTHWARD DISPLACEMENT OF THE UPPER LOW INHABITING THE NORTHEASTERN U.S. WHILE IT HAD ITS OWN ENSEMBLE SUPPORT...NONE OF THE OTHER GUIDANCE SHOWED ANY DISCERNIBLE SIMILARITIES TO THE GFS/GEFS. THROUGH DAY 5...PRIMARILY UTILIZED THE 12Z ECMWF/UKMET WITH SUBTLE CONTRIBUTIONS FROM THE 12Z ECMWF/NAEFS ENSEMBLE MEANS. KEPT A SMALL AMOUNT OF THE 12Z ECMWF INTO DAY 6 TO MAINTAIN THE STRENGTH OF INDIVIDUAL FEATURES BEFORE REVERTING TO ALL ENSEMBLE MEANS FOR THE DAY 7 FORECAST. ...WEATHER HIGHLIGHTS... FAIRLY WARM TEMPERATURES ARE EXPECTED EARLY IN THE PERIOD GIVEN THE EXPANSIVE RIDGE EXTENDING FROM THE GREAT PLAINS TO THE SOUTHEASTERN U.S. FORECAST ANOMALIES ARE LIKELY TO BE IN THE 10 TO 15 DEGREE ABOVE AVERAGE RANGE AS HIGHS SOAR INTO THE MID/UPPER 90S ACROSS THE REGION. THESE VALUES SHOULD COME BACK DOWN A BIT AS HEIGHTS BEGIN TO RELAX IN RESPONSE TO THE APPROACHING SOUTHERN STREAM SYSTEM. MEANWHILE...EXPECT SIMILAR ANOMALIES BUT ON THE BELOW AVERAGE SENSE ALONG THE WEST COAST...PARTICULARLY DURING THE DAY 5-7 PERIOD. THIS WILL ALSO HOLD TRUE OVER THE GREAT LAKES AND NEW ENGLAND AS THE CORE OF LOWER HEIGHTS SWINGS THROUGH ESTABLISHING NORTHWESTERLY FLOW IN ITS WAKE. EXCEPT FOR THE SOUTHWESTERN STATES...IT APPEARS MOST OTHER LOCATIONS IN THE U.S. SHOULD SEE INCREASING CHANCES FOR PRECIPITATION. THE MOST ACTIVE REGION SHOULD BE IN RESPONSE TO THE SHORTWAVE LIFTING OUT OF THE FOUR CORNERS INTO THE GREAT PLAINS. MODELS CONTINUE TO SHOW ACTIVE CONVECTION ANYWHERE FROM THE CENTRAL/NORTHERN PLAINS INTO THE UPPER GREAT LAKES. AN ADDITIONAL AREA OF FOCUSED PRECIPITATION MAY OCCUR ALONG A STALLED FRONT EXTENDING FROM THE LOWER MID-ATLANTIC BACK THROUGH THE LOWER OH VALLEY. RUBIN-OSTER