Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 746 PM EDT Mon Jun 19 2023 Valid 12Z Fri Jun 23 2023 - 12Z Tue Jun 27 2023 ...Emerging heavy rain threat for Kodiak Island and South-Central Alaska by later this weekend... ...Guidance Evaluation/Preferences... The 12 UTC GFS/UKMET solutions seem best clustered with GEFS/ECMWF ensembles and WPC continuity valid for Friday and Saturday, forecast spread has increased compared to the last few days. This incrreasingly over time lends preference for still quite compatible GEFS/ECMWF ensemble means that were used for the Sunday-next Tuesday in a period with slowly but steadily decreasing predictability. Moderate adjustments were manually applied, primarily to offshore low pressure systems, to offset inherent weakening from the blending process to ensure sufficient depth given still likely favorable upper support despite growing uncertainties. ...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 by Friday. Expect adjacent areas down through the northern Interior will experience unsettled conditions including lingering winds and precipitation. Meanwhile, an energetic/active storm flow from 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 and into next week. This offers potential for a protracted periods of high winds/waves and wrapping enhanced rains. Enhanced winds and rains should work steadily but slowly eastward, and increasingly this weekend into early next week to southwest/western Alaska and the Interior, but especially with deeper moisture underneath with additional triple point low focus into Kodiak Island and South-Central Alaska where there is a threat for heavier rainfall. Kodiak Island may also be prone to runoff/rockslide issues to monitor in this pattern. Activity should be slow to work eastward toward Southeast Alaska as partially shielded by ambient/amplified eastern Gulf of Alaska to Interior to Southeast Alaska upper ridging. 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