ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 245 PM EDT MON MAY 19 2014 VALID 12Z FRI MAY 23 2014 - 12Z TUE MAY 27 2014 ...PATTERN OVERVIEW...GUIDANCE/UNCERTAINTY ASSESSMENT...SENSIBLE WEATHER HIGHLIGHTS... AN AMPLIFIED PATTERN ALOFT CONTINUES INTO THE UPCOMING WEEKEND AS BOTH ARCTIC/INTERIOR AND GULF OF AK TROUGH ENERGIES FOCUS SYSTEM ORGANIZATION TO THE LEE OF A BERING SEA/STRAIT RIDGE. IN THIS PATTERN COLD AIR SETTLES DOWN THROUGH THE INTERIOR THIS WEEK BUT SHOULD MODIFY LATER AS APPROACHING NERN ASIAN SYSTEM ENERGY TRIES TO BREAKDOWN THE BERING RIDGE EARLY NEXT WEEK IN A POSSIBLE TRANSITION TO A SOMEWHAT LESS DEFINED FLOW PATTERN. MEANWHILE FARTHER SOUTH...SLOWLY APPROACHING GULF OF ALASKA LOW SYSTEM DEVELOPMENT AND DEEPER MOISTURE SHOULD COMBIME WITH TOPOGRAPHY TO SUPPORT LOCALLY HEAVY SERN ALASKAN AND TO A LESSER EXTENT SRN ALASKAN PRECIPITATION. WPC ALASKAN MEDIUM RANGE SURFACE FRONTS/PRESSURES AND 500 MB PROGS ALONG WITH ASSOCIATED HIGH RESOLUTION SENSIBLE WEATHER GRIDS HAVE BEEN PRIMARILY DERIVED FROM A BLEND OF THE 00 UTC ECMWF/ECMWF ENSEMBLE MEAN. THESE GUIDANCE CHOICE FLOW FORECASTS HISTORICALLY AND CURRENTLY TEND TO BE ON THE LESS PROGRESSIVE/MORE AMPLIFIED SIDE OF THE FULL ENVELOPE OF ALL GUIDANCE. THIS SEEMS A GOOD WAY TO GO FOR ALASKA AND ADJOINING WATERS GIVEN HIGH MID-UPPER LEVEL RIDGE AMPLITUDE CENTERED TO THE WEST OF THE STATE WELL INTO MEDIUM RANGE TIME SCALES. WHILE RUN TO RUN CONTINUITY OF THE DETERMINISTIC ECMWF HAS NOT BEEN STELLAR LATELY...THE ADDED DETAIL MAY OFFER SOME SKILL AS THE LATEST 00 UTC ECMWF RUN SEEMS TO BE REASONABLY COMPATABLE TO A SMOOTHED 00 UTC ECMWF ENSEMBLES MEAN AT LEAST INTO NEXT WEEKEND IN A PATTERN WITH NEAR AVERAGE OVERALL PREDICTABILITY. SCHICHTEL