ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 220 PM EST FRI JAN 13 2017 VALID 12Z TUE JAN 17 2017 - 12Z SAT JAN 21 2017 ...VERY COLD TEMPERATURES LIKELY FOR MUCH OF INTERIOR ALASKA NEXT WEEK... ...OVERVIEW AND GUIDANCE PREFERENCES... SYNOPTIC SETUP REMAINS CONSISTENT FOR NEXT WEEK AS AN UPPER LOW REMAINS ANCHORED OVER WESTERN ALASKA. A COUPLE SHORTWAVES WILL FLOW AROUND THE LARGE CIRCULATION AND LIFT INTO SE ALASKA EARLY IN THE PERIOD BEFORE ONLY MINOR DISTURBANCES ARE EXPECTED TO ROUND THE BASE. A BLEND OF THE RECENT 12Z GFS/06Z GEFS MEAN AND 00Z ECMWF/ECENS MEAN OFFERED A REASONABLE STARTING POINT THROUGH ABOUT NEXT THU/FRI BEFORE SMALLER TIMING DIFFERENCES RESULT IN A MYRIAD OF SFC LOWS OVER THE GULF. SYSTEM SOUTH OF THE ALEUTIANS ON TUE MAY HAVE A LEAD SFC WAVE/LOW NEAR HAIDA GWAII (VERY LOW PREDICTABILITY THOUGH THERE IS A CLUSTER OF ENSEMBLE MEMBERS WITH LOW PRESSURE IN THE VICINITY). PARENT LOW SHOULD LIFT TOWARD THE PANHANDLE (00Z ECMWF WAS ON THE SOUTHERN FRINGE OF THE ENSEMBLE CLUSTERING) AND LINGER IN THE GULF THEREAFTER. OTHER WEAK FEATURES MAY GAIN ENOUGH STRENGTH TO BE REFLECTED AT THE SURFACE BUT OTHERWISE NO DEFINABLE FRONT IS EXPECTED. BY NEXT WEEKEND (SAT 1/21) THE PATTERN APPEARS TO AMPLIFY BETWEEN JAPAN AND KAMCHATKA WHICH WOULD SUPPORT A FRONTAL SYSTEM NEARING THE WESTERN ALEUTIANS. ...WEATHER HIGHLIGHTS... AN EXTENDED PERIOD OF WELL BELOW AVERAGE TEMPERATURES ARE EXPECTED FOR INTERIOR ALASKA AS 850MB TEMPERATURE ANOMALIES ARE FORECAST TO BE IN THE -2 TO -3 SIGMA RANGE. ACTUAL 850MB TEMPERATURES OF -25 TO -30C ARE LIKELY IN THE COLD INTERIOR (ABOUT 5-10% OF ENSEMBLE MEMBERS DIP BELOW -35C). THIS MAY SUPPORT RECORD COLD TEMPERATURES BUT WILL BE DEPENDENT ON CLOUD COVER EACH NIGHT. ENSEMBLE SPREAD EXCEEDS 60F SO CONFIDENCE IS LOW IN DETERMINISTIC TEMPERATURES AT THIS LEAD TIME. EKDMOS 10TH PERCENTILE VALUES DIP TO BELOW -50F IN FAIRBANKS AND MCGRATH (RECORDS ARE IN THE -50S TO AROUND -60). ANCHORAGE SHOULD BE LESS COLD BUT STILL WELL BELOW AVERAGE (10TH PERCENTILE VALUES STRADDLE RECORD LOW MIN/MAX TEMPERATURES FROM WED THRU THE FOLLOWING SUN). PRECIPITATION SHOULD BE CONFINED MOSTLY TO THE PANHANDLE WITH LIGHTER SNOW OVER SW ALASKA AROUND THE UPPER LOW. NEAR TO ABOVE AVERAGE TEMPERATURES ARE FORECAST IN THE SOUTHEAST CORNER AND PANHANDLE. FRACASSO