Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 525 PM EST Mon Dec 26 2022 Valid 12Z Fri Dec 30 2022 - 12Z Tue Jan 03 2023 ...Major Storm to produce a New Year's Weekend Heavy Precipitation/High Wind Threat for the Alaskan Peninsula/Kodiak Island and Coastal Southcentral Alaska... ...Weather/Hazards Highlights and Guidance/Predictability Assessment... Models and especially ensemble means offer a reasonably similar mid-larger scale pattern evolution over medium range time scales, bolstering forecast confidence. However, models still show ample differences with embedded smaller scale weather systems/features. Noteable differences and uncertainties include modest weather focusing upper impulse/low translations out from northwest Alaska, with the ensemble means reasonably brokering a middle ground with depcition of a weakness aloft to round out 2022. Elsewhere, guidance differences relate to the complex interactions of upper trough/low energies and enhanced local weather focuses rotating out from the near the Aleutians to the Gulf of Alaska along with lead low/system energies working into the Gulf from the North Pacific in active flow. A favored composite of the 12 UTC GFS/ECMWF/Canadian and GEFS/ECMWF ensemble means seems to provide a good forecast basis late week before shifting to more compatible and better than usually detailed ensemble means heading into 2023 to mitigate smaller scale system variance. As such, there remains a quite favorable signal to ring in 2023 with development and track of a deep low/storm to the south of the Aleutians and into the Gulf of Alaska. The aforementioned favored guidance composite has seemed to begin to lock into a main feature that currently has good observational data coverage over Asia and is slated to generally track bodily eastward over the northern Pacific toward Alaska. This potentially potent storm with low pressure below 960mb given upper support could offer a significant maritime to coastal wind/waves threat. Lead wrapping moisture inland into the Alaskan Peninsula/Kodiak Island and Southcentral Alaska, and to a lesser extent the Panhandle, could fuel a multi-day heavy precipitation and high wind threat. WPC product continuity is well maintained in this forecast plan collaborated between WPC and Alaskan weather offices. Schichtel Hazards: - Heavy precipitation for portions of the Alaska Peninsula and Kodiak Island to Southcentral Alaska, Sat-Mon, Dec 31-Jan 2. - High winds for portions of the eastern Aleutians through Southcentral Alaska, Sat-Fri, Dec 31-Dec 2. 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