EXTENDED FORECAST DISCUSSION...AMENDED NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1253 AM EST THU FEB 09 2017 VALID 12Z SUN FEB 12 2017 - 12Z THU FEB 16 2017 PATTERN OVERVIEW/GUIDANCE EVALUATION/PREFERENCES ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ WHILE THE GUIDANCE REMAINS IN GOOD AGREEMENT ON AN INCREASINGLY AMPLIFIED UPPER PATTERN ACROSS NORTH AMERICA, WITH GENERALLY ABOVE NORMAL 500 HPA HEIGHTS ACROSS MUCH OF THE LOWER 48 (GENERALLY WARMER THAN AVERAGE), THE MOST CONTENTIOUS PART OF THE FCST CONTINUES TO BE THE UPPER LOW MOVING OUT OF THE SOUTHWEST. THE 12Z ECMWF/ITS ENSEMBLE MEAN ARE QUICKEST, WHILE THE 18Z GFS/18Z GEFS MEAN ARE SLOWEST, WITH THE 12Z CANADIAN IN THE UNUSUAL POSITION OF BEING A MIDDLE GROUND. THE FLOW PATTERN FAVORS A SLOWER MOTION TO THIS SYSTEM AS NO KICKER SHORTWAVES APPEAR TO BE PRESENT TO LURE IT QUICKLY AWAY FROM THE SOUTHWEST. SINCE IT IS MUCH MORE LIKELY THE ECMWF IS QUICK RATHER THAN THE GFS BEING SLOW, THE PRESSURES/500 HPA HEIGHTS/WINDS ARE BASED ON MAINLY AN 18Z GFS/12Z UKMET/12Z CANADIAN COMPROMISE EARLY ON. LATER, WHEN THE GFS IS A SLOW OUTLIER, TRANSITIONED TOWARDS A COMPROMISE OF THE 12Z ECMWF/12Z ECMWF ENSEMBLE MEAN/12Z NAEFS MEAN/18Z GFS TO LOWER WEIGHTING OF THE GFS. THE TEMPERATURES, RAIN CHANCES, CLOUDS, WEATHER, AND DEW POINTS WERE BASED ON ABOUT 50% ENSEMBLE MEAN AND 50% DETERMINISTIC (MIX OF 12Z CANADIAN/18Z GFS/12Z ECMWF). THE DAYS 4-7 QPF IS BEING BASED ON A 18Z GFS/00Z GFS/ECMWF COMPROMISE IN AN EFFORT TO WEIGHT TOWARDS A SLOWER SOLUTION. WEATHER HIGHLIGHTS/THREATS ~~~~~~~~~~~~~~~~~~~~~~~~~~ THE SOUTHWESTERN UPPER LOW WILL LIKELY GENERATE SOME ENHANCED AREAS OF RAIN AND HIGHER ELEVATION SNOW OVER THE FOUR CORNERS REGION DURING THE WEEKEND AND INTO THE START OF NEXT WEEK. AS THIS FEATURE DRIFTS EAST, IT SHOULD PROMOTE A THREAT FOR HEAVY RNFL ACROSS PARTS OF THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY. EXPECT EXTREME NORTHERN PARTS OF THE EAST TO SEE SNOW/WINTRY PCPN TYPES WITH THE WAVE TRACKING OUT OF THE PLAINS AND DEEPENING NEAR NEW ENGLAND... WITH SOME RAIN TO THE SOUTH. BY NEXT WEDNESDAY/THURSDAY, THE PACIFIC NORTHWEST AND NORTHERN CA SHOULD SEE MODERATE TO HEAVY PRECIPITATION. THE MOST ANOMALOUS TEMPERATURES WILL BE EARLY ON FROM THE CENTRAL AND SOUTHERN PLAINS INTO THE EAST AHEAD OF A COLD FRONT. A BROAD AREA OF PLUS 10-20F ANOMALIES FOR HIGHS AND PLUS 15-30F ANOMALIES FOR MORNING LOWS SAT-SUN. SOME DAILY RECORDS FOR HIGHS/WARM MINIMA ARE PSBL. THE NORTHERN TIER SHOULD BE MODERATELY ABOVE NORMAL MOST OF THE PERIOD. THE WEST SHOULD SEE TEMPERATURES NEAR NORMAL, TRENDING ABOVE NORMAL CENTRAL AND SOUTHERN AREAS MID NEXT-WEEK. ROTH/RAUSCH