ALASKA EXTENDED FORECAST DISCUSSION NWS WEATHER PREDICTION CENTER COLLEGE PARK MD 121 PM EDT SAT MAY 13 2017 VALID 12Z WED MAY 17 2017 - 12Z SUN MAY 21 2017 THE GUIDANCE SHOWS VERY GOOD AGREEMENT ON THE EXPECTED FLOW PATTERN NEAR AK INTO NEXT SUNDAY, WITH ONE CYCLONE FADING NEAR THE ALEUTIANS AS ANOTHER SWEEPS SOUTH OF THE CHAIN TRACKING TOWARDS THE AK PENINSULA NEXT SUNDAY. DUE TO THE AGREEMENT, USED A COMPROMISE OF THE 06Z GFS, 12Z GFS, 00Z ECMWF, 00Z CANADIAN, AND 00Z UKMET EARLY ON BEFORE BLENDING IN INCREASING PERCENTAGES OF THE 00Z ECMWF AND 00Z NAEFS ENSEMBLE MEANS TO DEAL WITH UNCERTAINTY/DETAIL ISSUES FROM FRIDAY THROUGH NEXT WEEKEND. RAIN CHANCES THIS PERIOD LIE NEAR THE SOUTHERN COAST WITH ONSHORE FLOW ASSOCIATED WITH THE PAIR OF CYCLONES MOVING BY SOUTHWEST AK AND THE ALEUTIANS. RAINFALL SHOULD BE MODERATE TO HEAVY, WITH OVERALL AMOUNTS NOT PARTICULARLY EXTREME. BREEZY CONDITIONS THROUGH THE PERIOD SHOULD STRETCH FROM THE ALEUTIANS EASTWARD TO KODIAK ISLAND. OTHERWISE, THE ARCTIC DRAPE SHOULD REMAIN NEAR THE NORTH SLOPE WHILE A THERMAL LOW/TROUGH PERSISTS TO THE SOUTH FROM CENTRAL/INTERIOR AK EASTWARD INTO THE YUKON AND NORTHWEST TERRITORIES. COOL OVERNIGHT TEMPERATURES GIVE WAY TO MILD READINGS DURING THE AFTERNOON AND EVENING HOURS ACROSS THE INTERIOR THIS PERIOD. THE COOLEST AIR SHOULD LIE ALONG AND NORTH OF THE NORTH SLOPE, AS IS TYPICAL. ROTH