Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 451 PM EDT Fri Mar 18 2022 Valid 12Z Tue Mar 22 2022 - 12Z Sat Mar 26 2022 ...Pattern Overview... A lingering main feature near Alaska for the medium range period will be a mean upper low with multiple centers of focus at times in the Gulf of Alaska. Energies near the Alaska Peninsula combined with an active storm track across the northeastern Pacific will serve to redevelop and reinforce mean low pressure across the Gulf into next week. A series of low pressure systems will bring a multi-day period of unsettled weather through the Panhandle and occasionally up into the southern coast. A low near the Kamchatka Peninsula will swing a cold front through the Aleutians and lead low focus over the Bering Sea next week, with a blocky/warming upper ridge setting up over a dry northwest/northern Alaska by early period to limit eastward progression. Downstream in this pattern, modestly cooling upper troughing would have a period to amplify more over an unsettled Mainland before the pattern will likely evolve and moderate. ...Guidance/Predictability Assessment... WPC Alaskan medium range guidance was primarily derived from a composite of best clustered guidance from the 12 UTC GFS/EC/UKMET for Days 4/5 (Tuesday/Wednesday) before switching to a blend of the semi-compatible GEFS/NAEFS/ECMWF ensemble means for days 6-8. This forecast plan maintains excellent WPC product continuity in a pattern whose overall predictability lowers from average to below average over time. The WPC Hazards Outlook Desk has also added a threat for heavy precipitation (coastal rains/terrain snows) for the Southeast Panhandle centering around Tuesday considering wet antecedent conditions. The models are now in better agreement for there and nearby regions for this time period and the forecast also now has increased ensemble support. ...Weather/Hazard Highlights... Precipitation through much of the period is expected to focus from coastal south-central Alaska to especially the southeastern Alaskan Panhandle given the general northern Pacific storm track into the Gulf to include several deepened lows that will each offer a maritime threat. Recent heavy rain/snow across the area could make it more sensitive to additional impacts. Amounts seem most likely to pick up early next week with best organized/deepened system approaches and accordingly, the WPC Hazards Desk has added a threat for heavy precipitation to focus across Southeast AK around Tue now that guidance is in better agreement. Farther north, some periods of snow are also possible with unsettled conditions aloft over mainly the eastern Interior through mainly mid week. Meanwhile, slow low/frontal system progression over the Aleutians and the Bering Sea next week should still lead to subsequent low re-development and weather focus through southwest Alaska to the western Gulf of Alaska into later next week where wrapping winds/precipitation could also present an emerging maritime and coastal focus. Schichtel Hazards: - Heavy precipitation across portions of the Alaska Panhandle, Tue, Mar 22. 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