Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 547 PM EDT Sun Jun 18 2023 Valid 12Z Thu Jun 22 2023 - 12Z Mon Jun 26 2023 ...Guidance Evaluation/Preferences... The 12 UTC GFS/ECMWF/CMC/UKMET and GEFS/NAEFS/ECMWF/Canadian ensemble solutions seem well clustered, but the ECMWF seems too progressive with height falls across the southern to southeastern tier of Alaska and the Gulf of Alaska by next weekend given overall flow amplitude/persistence and lack of ensemble support. An otherwise composite blend with a slight focus on the higher resolution models acts to maintain good WPC product continuity with detail consistent with a pattern with above normal predictability. Additional adjustments were manually applied, primarily to offshore low pressure systems, to offset inherent weakening from the blending process and ensure sufficient depth given favorable upper support. ...Pattern Overview and Weather/Hazards Highlights... A strong closed low/amplified trough aloft and surface focus over the North Slope and the adjacent Arctic Ocean should along with weather focus eject eastward and away into mid-later week. Expect northwest/western Alaska through the northern Interior and North Slope to the Arctic Ocean will experience unsettled conditions to include multiple periods with enhanced winds and precipitation along with some potential for Brooks Range rainfall/snowmelt fueled local runoff issues to monitor. Well to the south, a closed upper low and surface low/frontal system with deepened moisture will dig over the Gulf of Alaska mid-later week. Flow around the system favors lingering enhanced rainfall chances northward into the Alaskan Peninsula/Kodiak Island and South-Central, but activity should be slow to work eastward toward Southeast Alaska as shielded by amplified eastern Gulf of Alaska to Interior to Southeast Alaska upper ridging. Upstream, a continued and highly energetic/active storm flow off eastern Asia and the western Pacific will continue to churn up additional low pressure systems to include deepened storm tracks toward the Aleutians and southern Bering Sea as a protracted maritime threat this week into next that offers potential for high winds/waves and wrapping enhanced rains. Enhanced winds and rains should work steadily but slowly eastward, and increasingly by next weekend into early next week to southwest/western Alaska and the Interior as well as underneath with additional triple point low focus into the Alaska Peninsula/Kodiak Island and South-Central. Schichtel Additional 3-7 Day Hazard Information can be found on the WPC medium range hazards outlook chart at: https://www.wpc.ncep.noaa.gov/threats/threats.php WPC medium range Alaskan products including 500mb, surface fronts/pressures progs and sensible weather grids can also be found at: https://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif https://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml https://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html