Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 402 PM EST Wed Jan 26 2022 Valid 12Z Sun Jan 30 2022 - 12Z Thu Feb 03 2022 ...Overview and Guidance/Uncertainty Assessment... Significant uncertainties in the upcoming medium range forecast period pattern mainly result from embedded system evolutions/interactions within a large scale Omega block settled over Alaska and surrounding areas. This results in a highly chaotic array of surface lows near the Aleutians and to a lesser degree the Gulf of Alaska. Guidance solutions diverge significantly with embedded system evolutions from short through medium range time scales with development and uncertain breakdown of Omega blocking over/near Alaska, especially with lows rotating into the block position near the Aleutians. The 12 UTC ECMWF has issues, but overall seems the best overall fit with GEFS/ECMWF ensembles and WPC continuity days 4 into 6 (Sun into Tue). Accordingly added the ECMWF to a composite with the ensemble means in this time frame to add some detail consistent with the pattern. Used a composite of the generally compatible ensemble means later Tue into next Thu (later Day 6 to Day 8), shifting majority weighting to ECMWF ensembles that flows a bit better from the day 4-6 embedded system locations and depths. WPC product continuity is decently maintained with this forecast plan. ...Weather/Hazard Highlights... Arctic high pressure slowly weakens during the medium range period, but keeps most of mainland Alaska dry. Meanwhile, storm systems in the Gulf especially early in this forecast period will translate to unsettled conditions along the Southeast coast and Panhandle regions. Moderate to heavy precipitation there will shift slowly southward this weekend with conditions tending to dry out by early next week. Meanwhile, a number of highly uncertain storm systems offer potential to bring highly unsettled periods of wet and windy weather to the Aleutians through this period, and potentially with slow erosion of the Omega block with leading flow downstream into mid-later next week with otherwise generally benign weather conditions for the AKpen/Kodiak Island and the Alaskan southern tier. Schichtel Hazards: - Heavy precipitation across the Alaska Panhandle, Sat, Jan 29. 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