Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 557 PM EDT Sat Apr 25 2020 Valid 12Z Wed Apr 29 2020 - 12Z Sun May 03 2020 ...Guidance/Predictability Assessment... Upper pattern across Alaska during the extended forecast period shows ridging near the Bering Strait slowly migrating toward the North Slope as a trough splits a piece off southward into Southcentral Wednesday into Thursday. Additional troughing out of the Bering is forecast to move east-southeastward by next weekend with a defined system south of the Gulf. The 12Z GFS/ECMWF (and UKMET through Friday) showed relatively good consensus with the ensemble means during the period, and a blend of these solutions was used as a forecast starting point. Aleutian system on Wed will split to the southeast as its old parent low weakens through the week. That system to the south is forecast to lift back toward the southern Panhandle by next weekend but the main low may stay offshore. Upper pattern would prevent much northern movement as the upper high shows no signs of budging by then. Over the Interior, models have wavered on how strong an upper trough may dive into Southcentral which would bring another shot of cooler air all the way to the Gulf. 12Z guidance somewhat splits this trough, allowing a portion (perhaps the majority) to run eastward into Canada with only weaker troughing sinking to the Gulf. Ensembles have yet to form a consensus or a defined trend as the shape/orientation of the forcing upper high is uncertain. ...Weather/Threats Highlights... Pattern remains rather unsettled for the Panhandle with lingering rain/snow Wed-Thu as an old parent low weakens in the Gulf. System next weekend to the south would bring in at least some precipitation near/ahead of the occlusion with the heavier rain/snow likely being forced into British Columbia but perhaps into the southern Panhandle, too. The Interior, by contrast, will be much nearly precipitation-free owing to the upper and sfc high. The Aleutians will see generally lighter rain after Wednesday as the sfc low slowly weakens. After a cooler than normal period at the start of the week over most of the mainland, temperatures will moderate back to within several degrees of normal for most of the state with the better chance of sustained above average temperatures near the Bering Sea near the upper ridge axis. Fracasso Additional 3-7 Day Hazard information can be found on the WPC medium range hazards 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