Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 519 PM EDT Sun Sep 24 2023 Valid 12Z Thu Sep 28 2023 - 12Z Mon Oct 02 2023 ...Possible Aleutians to Southern/Southeast Alaska offshore low... ...Guidance Evaluation/Preferences... Rapidly building forecast spread and run to run continuity issues quickly become unmanageable with deterministic model guidance, lending preference Days 4-8 for a composite of now quite compatible GEFS/NAEFS/ECMWF ensemble means. Given uncertainties, there does still seem to be a better than expected signal for development of a threatening Northern Pacific low set to track northeastward to the state heading into/through next weekend. The ensemble mean track, depth and timing is in between 12 UTC GFS/ECMWF guidance. Manual adjustments are applied to ensure sufficient storm depth to offset the mean blending process. WPC product continuity is best maintained in this manner. ...Weather/Hazards Highlights... A relatively benign weather pattern may reactivate later this week. Flow wrapping around a leading southern Bering Sea low favors some moderate precipitation into western and southwest Alaska Thursday, lingering into Friday along with some unsettled flow. Meanwhile, the forecast signal continues to grow in support of development and track of a well orgainzed Pacific storm system to approach the Aleutians late this week. This storm still offers quite of bit of uncertainty, but would offer maritime and coastal high wind/wave threats along with wrapping heavy rains. The main impacts would then spread across the northern Gulf of Alaska and inland into the AKpen/Kodiak Island through Southcentral to Southeast Alaska through next weekend. 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