Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 520 PM EST Wed Jan 12 2022 Valid 12Z Sun Jan 16 2022 - 12Z Thu Jan 20 2022 ...Guidance/Uncertainty Assessment... The overall synoptic scale pattern across the Alaska domain is generally handled well by the 12Z guidance. A couple of weaker shortwave troughs will pass through the northern Gulf region during the Sunday-Monday time period, with one affecting the southern mainland while another low lifts northward into the Panhandle region. Both of these systems gradually become absorbed by the mid-upper level flow and weaken. Meanwhile, guidance continues to show a rather large, closed low settling across the western Aleutians and then settling southeastward across the North Pacific through the early to middle part of next week. There is still significant model spread within this feature, with several embedded pieces of vorticity rotating through the flow that are difficult to time and pinpoint during this time range. There are signals of low pressure developing on the southern periphery of this system which then lifts northeast toward the mainland. Most of the deterministic models have this signal but with wide range in timing and track. Taking these factors into account, the WPC fronts/pressures forecast was primarily derived from a UKMET/CMC/ECMWF blend through Monday, and then more of the ensemble means while still maintaining some of the ECMWF/CMC/GFS through Day 8. ...Weather/Hazard Highlights... A series of low pressure systems will impact the Alaska panhandle going into the 16th/17th, and these disturbances could bring widespread moderate to locally heavy precipitation (mountain snow, valley rain) as well as high winds and waves along the coast. The rest of the mainland is expected to be relatively dry (a weakening system will pass through the southern mainland days 3-4) as a closed low settles over the Aleutians. By the end of forecast period, waves of low pressure will become possible underneath the closed low and this could bring widespread precipitation to the eastern Aleutians and the southern mainland later next week. Hamrick/Taylor Hazards: - Heavy precipitation across portions of the Alaska Panhandle, Sat, Jan 15. 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