EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 1108 AM EST FRI FEB 26 2016 VALID 12Z MON FEB 29 2016 - 12Z FRI MAR 04 2016 ...GUIDANCE AND UNCERTIANTY ASSESSMENT... RECENT DETERMINISTIC MODELS AND ENSEMBLE MEMBERS OFFER ABOVE NORMAL FORECAST SPREAD AND RUN TO RUN CONSISTENCY ISSUES DAYS 3-7...WITH ENSEMBLE SYSTEMS TENDING TO TREND DAILY IN A SIMILAR FASHION TO THEIR SISTER DETERMINISTIC RUNS. THIS DOES NOT BODE WELL FOR PREDICTABILILTY. THIS IS ESPECIALLY EVIDENT CONSIDERING AN UNCERTAIN EMPHASIS OF A SERIES OF SMALL-MID SCALE NRN AND SRN STREAM SYSTEMS SLATED TO WORK AROUND OR THROUGH AN ESTABLISHED MID-UPPER LEVEL WRN NOAM RIDGE BEFORE DIGGING INTO A MEAN EAST-CENTRAL CANADA/US MEAN TROUGH POSITION ALOFT. AM HESITANT GIVEN RECENT MODEL VARIANCE TO ADJUST WPC GUIDANCE TOO RADICALLY FROM CONTINUITY PENDING MORE SUSTAINED MODEL AND ENSEMBLE TRENDS/SUPPORT. THEREFORE...THE WPC PRODUCT SUITE LEANED STRONGLY ON CONTINUITY...ESPECIALLY WITH THE PATTERN EVOLUTION ALOFT...BUT DID TRY TO INCORPORATE A BIT OF MORE CLUSTERED NEWER GUIDANCE FROM THE 06 UTC GFS/GEFS AND 00 UTC ECMWF/ECMWF ENSEMBLE MEAN. ...PATTERN HIGHLIGHTS/THREATS... THIS PATTERN SEEMS HIGHLIGHTED BY PERIODIC BREAKTHROUGH OF MID-LATITUDE PACIFIC ENERGY THROUGH THE WRN US MEAN POSITION SPREADING MODEST PCPN ACROSS THE NWRN US TO THE N-CENTRAL ROCKIES INTO MON/MIDWEEK/AND THEN LATER WEEK. ACTIVITY WILL FOCUS OVER COASTAL AREAS AND INLAND OVER FAVORED TERRAIN. THIS UNCERTAIN ENERGY STREAM ALONG WITH ADDITIONAL NRN STREAM SHORTWAVE TROUGH DIGGING TO THE LEE OF THE RIDGE POSITION FROM W-CENTRAL CANADA INTO AN ERN US MEAN TROUGH ALOFT ALSO SETS THE STAGE FOR PERIODIC CYCLOGENESIS AND FRONTOGENESIS DOWNSTRREAM OVER THE CENTRAL TO ERN US. DYNAMIC SUPPORT ON PAR FOR WELL ORGANIZED BUT UNCERTAIN LOW TRACKS SHOULD BE ABLE TO TAP DEEPENING GULF OF MEXICO THEN ATLANTIC MOISTURE FOR WIDESPREAD PCPN POTENTIAL. WPC SURFACE PROGS HIGHLIGHT SUCH A THREAT WITH BEST POTENTIAL FOR SYSTEM GENESIS/EXPANSION OVER THE E-CENTRAL TO ERN US MON INTO WED AND THEN AGAIN THU/FRI. THESE SYSTEMS COULD ENHANCE WARM SECTOR CONVECTION/RAINFALL AND OFFER A WINTER WEATHER THREAT ON THE NRN/NW PERIPHERY OF THE OVERALL PCPN SHIELD. SCHICHTEL