ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 308 PM EDT FRI JUL 31 2015 VALID 12Z TUE AUG 04 2015 - 12Z SAT AUG 08 2015 ALASKA FORECAST DISAGREEMENT OCCURS IN 2 AREAS: THE FIRST REVOLVES AROUND HOW ENERGY SOUTH OF THE ALEUTIANS CONSOLIDATES AND EITHER MEANDERS IN PLACE OR SLIDES EAST INTO THE GULF. THE 12Z GFS TUE-WED 04-05 AUG MADE A LARGE CHANGE FROM ITS 06Z RUN WITH LOW PRESSURE MOVING A DAY FASTER THAN THE PRIOR RUN ACROSS THE GULF OF AK. WITH LOW CONFIDENCE IN THE LARGE RUN TO RUN CHANGE IN THE GFS...THE 12Z GFS RUN WAS NOT USED IN THE FORECAST. THE ECMWF/ECENS MEAN REPRESENTS BETTER CONTINUITY AND WAS USED IN CONJUNCTION WITH THE 00Z NAEFS AND 06Z GEFS MEAN. WITH LOW PRESSURE SFC/ALOFT PERSISTING OVER THE BERING...HIGHER HEIGHTS OVER MAINLAND AK LEADS TO LOW LEVEL AND SURFACE TEMPS ABOVE NORMAL MUCH OF THE PERIOD ACROSS SOUTH AND CENTRAL AK. TO THE NORTH... TREND HAS BEEN TOWARD A BIT MORE TROUGHING PUSHING THROUGH THE NORTH SLOPE... AND THE FRONTAL BOUNDARY IN THE AREA DRIFTS SLOWLY SOUTH ACROSS NORTHERN AK. SCATTERED SHOWERS AND STORMS ARE EXPECTED NEAR THE FRONTAL BOUNDARY IN NORTHERN AK. THE 2ND AREA OF DISAGREEMENT IS IN NORTHERN AK. MANUAL PROGS TRENDED AWAY FROM THE 12Z GFS BY NEXT THU/FRI 06-07 AUG AS THE GFS WAS AN OUTLIER IN DEVELOPING STRONG LOW PRESSURE AND MOVING IT ALONG THE NORTH COAST...BREAKING CONTINUITY AND IN DISAGREEMENT WITH THE OTHER MODELS/ENSEMBLE MEANS...INCLUDING THE 12Z GEFS MEAN. PETERSEN