EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1042 AM EST TUE NOV 03 2015 VALID 12Z FRI NOV 06 2015 - 12Z TUE NOV 10 2015 ...OVERVIEW AND SENSIBLE WEATHER HIGHLIGHTS... A MODESTLY AMPLIFIED AND PROGRESSIVE UPPER PATTERN WILL KEEP THE WEATHER RATHER CHANGEABLE DURING THE MEDIUM RANGE PERIOD. A SYSTEM WILL LIFT THROUGH CANADA ON FRIDAY WITH ITS TRAILING FRONT BRINGING IN A COOLER AIRMASS TO THE EAST, AFTER A VERY WARM PRE-FRONTAL ENVIRONMENT. MANY RECORD HIGH MINIMUM TEMPS ARE LIKELY IN THE EAST ON FRIDAY THOUGH SOME WILL NOT HOLD UNTIL MIDNIGHT AS THE FRONT MARCHES EASTWARD. THE TAIL END OF THE FRONT WILL EASE INTO THE GULF AND ACROSS FLORIDA WHICH MAY ALLOW FOR HEAVIER RAIN TO LINGER IN THE LOWER MS VALLEY FRI-SUN. THE ENSEMBLES HAVE HINTED AT DEVELOPING A WEAK AREA OF LOW PRESSURE ALONG THE FRONT AS INCOMING ENERGY FROM THE SOUTHWEST STATES APPROACHES. NEXT SUN-TUE ANOTHER WESTERN CONUS SYSTEM WILL DIG THROUGH THE INTERIOR AND SPREAD FAIRLY WIDESPREAD LIGHT TO MODERATE RAIN/SNOW TO THE REGION. MOISTURE CONNECTION WILL BE LIMITED AS THE ENERGY HAS ORIGINS OVER ALASKA. NONETHELESS, THE COLDEST AIR OF THE SEASON MAY OVERSPREAD THE AREA WITH SUB-ZERO TEMPERATURES POSSIBLE FOR THE FIRST TIME SINCE LAST WINTER. ...GUIDANCE ASSESSMENT... MODELS AND ENSEMBLES REMAIN IN BETTER THAN AVERAGE SYNOPTIC AGREEMENT THROUGH THE PERIOD AS THE FLOW LIES IN BETWEEN ZONAL AND BLOCKED FLOW, WITH ENOUGH AMPLITUDE TO KEEP THE PATTERN MOVING. RECENT ECMWF AND GFS RUNS OFFER A GOOD COMPROMISE FOR A STARTING POINT ON FRI-SAT/D3-4. QUESTION START TO SURFACE IN THE GULF AROUND SUNDAY WHERE THE GFS RUNS HAVE BEEN FLATTER WITH THE PRESSURE PATTERN THAN THE ECMWF, WHICH SHOWS POTENTIAL FOR A SURFACE WAVE TO LIFT TOWARD THE NORTHERN GULF COAST. ENSEMBLES MIMIC THEIR DETERMINISTIC COUNTERPARTS AND THE CANADIAN CAMP DOES SHOW AT LEAST SOME INVERTED TROUGH MOVING EASTWARD QUICKER THAN THE ECMWF CAMP, SO OPTED TO SHOW A SLOWER TROUGH INTO THE ARKLAMISS BY MONDAY. TRENDED TO AN ECMWF/ECENS MEAN BLEND MID-PERIOD AND THEN TOWARD AN ECENS/NAEFS BLEND BY NEXT TUESDAY, WITH MUCH MORE EMPHASIS ON THE ECENS MEAN WHICH WAS MODESTLY STRONGER/SLOWER WITH THE WESTERN TROUGH, WHICH HAS BEEN THE TREND ACROSS ALL ENSEMBLES OVER THE PAST FEW CYCLES. FRACASSO