ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 346 PM EDT FRI JUN 16 2017 VALID 12Z TUE JUN 20 2017 - 12Z SAT JUN 24 2017 MODELS AND ENSEMBLES START OFF IN GENERAL AGREEMENT NEXT TUES WITH HAVING A LARGE UPPER LOW OVER THE GULF OF ALASKA/NERN PAC AND A COMPACT UPPER LOW OVER NORTHWEST ALASKA. MEANWHILE UPPER RIDGING ALOFT WILL EXTEND ACROSS THE CENTRAL PORTION OF THE STATE AND THIS WILL BE A THEME FOR A GOOD PORTION OF THE FORECAST PERIOD. HOWEVER, OPERATIONAL MODELS BEGIN TO DIVERGE AND VARY QUITE SIGNIFICANTLY AFTER THE LOW OVER NWRN AK SWEEPS THROUGH THE NRN TIER OF THE STATE AND THE GULF OF AK LOW GRADUALLY FILLS. THUS AFTER NEXT WED OR THURS, WPC DEPENDED ON ABOUT 70 PERCENT OF THE MODEL BLEND BEING MEANS TO CALM DOWN THE DETAILS AND HOPEFULLY CATCH THE ULTIMATE LARGE SCALE PATTERN. IN TERMS OF SENSIBLE WEATHER, THE GREATEST CHANCES FOR PRECIPITATION SHOULD STRETCH FROM SERN AK TO THE PANHANDLE WITH SOME LOCALLY HEAVY QPF ACROSS THE NRN TIER OF THE STATE. GEFS AND EC MEANS GENERALLY INDICATE 850MB TEMPS NEAR AVG THROUGHOUT THE FCST PERIOD. MUSHER