EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1051 AM EST TUE FEB 23 2016 VALID 12Z FRI FEB 26 2016 - 12Z TUE MAR 01 2016 ...OVERVIEW AND GUIDANCE/UNCERTAINTY ASSESSMENT... BIGGEST PICTURE VIEW IN THE MEDIUM RANGE IS IN GOOD AGREEMENT -- THIS MAINTAINS UPPER LOWS NEAR THE ALEUTIANS AND ALSO OVER HUDSON BAY. THE FLOW TO THE SOUTH OF THE FEATURES REMAINS RATHER UNRESOLVED AFTER THIS WEEKEND DUE TO SMALLER SCALE UNKNOWNS. THE CHALLENGE LIE IN TWO AREAS... THE FIRST IN THE NORTHEAST PACIFIC WHERE THE CIRCULATING SURFACE SYSTEMS WILL ATTEMPT TO PUSH WEAKENING FRONTS EASTWARD THROUGH A WEAKNESS IN THE RIDGE AND THE SECOND ALONG THE US/CANADIAN BORDER WHERE THE MODELS HAVE SHOWN LACKLUSTER CONTINUITY WITH HOW MUCH ENERGY PUSHES SOUTHWARD VERSUS EASTWARD -- AND MORE RELEVANTLY THE AMOUNT OF COLD AIR THAT FOLLOWS ALONG. OVERALL PREFERENCE IS TOWARD A MODEL/ENSEMBLE CONSENSUS THROUGH ABOUT SUNDAY BEFORE A SHIFT TOWARD A 00Z NAEFS/ECENS MEAN BLEND NEXT MON/TUE. THIS AVOIDS THE TRAPPINGS OF THE LATEST DETERMINISTIC RUNS -- RECENT ECMWF AND GFS RUNS FALL NEAR THE EDGE OF THE MULTI-CENTER ENSEMBLE ENVELOPE IN DIFFERENT AREAS OF NORTH AMERICA. FINALLY, EVEN THE ENSEMBLE MEANS ARE STRUGGLING A BIT TO PIN DOWN THE FLOW IN THE NORTH-CENTRAL/EAST NEXT WEEK WHICH LEADS TO BELOW AVERAGE CONFIDENCE. SPREAD IN THE ENSEMBLES IN SOME NORTHERN TIER LOCATIONS -- E.G. ND/SD/MN -- INCREASE TO AROUND 60F BETWEEN THE MIN/MAX ENSEMBLE MEMBERS FOR DAILY MIN/MAX TEMPS WHICH IS HIGHER THAN YOUR TYPICAL SPREAD EVEN FOR THOSE LOCATIONS. ...WEATHER HIGHLIGHTS/THREATS... IN THE EAST... ON FRIDAY, POST-FRONTAL COLD ADVECTION BRINGS A PERIOD OF LIGHT LAKE EFFECT SNOW WITH TERRAIN ENHANCEMENT SUPPORTING SOME CENTRAL/NORTHERN APPALACHIANS SNOW. THE WEEKEND OFFERS ANOTHER PERIOD OF SNOW IN THE GREAT LAKES/NORTHEAST WITH A LEAD FRONTAL SYSTEM AS THE LOW PASSES THROUGH SOUTHERN CANADA. SUBSEQUENT LOW DEEPENING IN THE CENTRAL PLAINS BY TUESDAY SHOULD SUPPORT AN EXPANDING AREA OF LIGHT SNOW IN THE NORTHERN PLAINS TO THE UPPER MS VALLEY/UPPER LAKES BY SUNDAY AND TO THE ST LAWRENCE VALLEY MONDAY. RAIN IS EXPECTED FARTHER SOUTH IN THE OH VALLEY AND MS VALLEY TO THE CENTRAL APPALACHIANS AND MID ATLANTIC STATES BY NEXT TUESDAY. UPSTREAM IN THE WEST... WEAKENING INBOUND SYSTEMS WILL SUPPORT MOSTLY LIGHT TO LOCALLY TERRAIN-ENHANCED MODERATE PRECIPITATION, PUNCTUATED BY SOME DRIER PERIODS IN BETWEEN FRONTAL PASSAGES. PATTERN SUPPORTS ABOVE AVERAGE TEMPERATURES IN THE WEST AND INTO THE PLAINS THANKS TO THE UPPER RIDGE WITH BELOW AVERAGE TEMPERATURES IN THE EAST THAT WILL MODERATE IN TIME. FRACASSO