Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 638 PM EST Wed Nov 16 2022 Valid 12Z Sun Nov 20 2022 - 12Z Thu Nov 24 2022 ...Overview... A strong upper ridge over the mainland of Alaska into this weekend should help to deflect the main storm track to the south. Several low pressure systems look to track from near/south of the Aleutians/north Pacific into the Gulf. This will likely bring a period of gusty winds and modest rainfall to places along the Southern Coast and Panhandle. The ridge should be strongest during the short range period and finally begin to break down and shift east as an upper low over eastern Russia sends troughing into the Bering Sea and Western Alaska during to early to middle part of next week. ...Guidance/Predictability Assessment and Preferences... Despite some normal timing and stength differences, the models generally show good agreement through about day 6/Tuesday as one upper low/surface low moves from just south of the Aleutians into the Gulf. This initial low should eventually weaken in favor of a second low which deepens as it lifts from the north Pacific and again into the Gulf next Wednesday-Thursday. By day 7-8, models begin to diverge more on the timing and strength of this low into the Gulf, along with some minor timing of amplified troughing across the Bering and into western Alaska. The CMC gets out of phase with the next system across eastern Alaska and into the northern Bering late period, but the GFS and ECMWF show good agreement with each other right now as well as the ensemble means (which are noticeably weaker, likely due to the uncertainties). The WPC forecast used a blend of the CMC, GFS, and ECMWF with the ensemble means through day 6. After this, removed the CMC from the blend and increased some the ensemble means. Throughout the period, the GFS and ECMWF seem match closest with the ensemble means. ...Sensible Weather and Potential Hazards... The initial surface low into the Gulf will contine to produce at least moderate, with some locally heavy, precipitation (coastal rain/mountain snows) this weekend from parts of the Southern Coast and the northern Panhandle. Activity should also linger into the early week but with more uncertainty on specific amounts. The second low into the Gulf should also bring additional unsettled weather to the region around the middle of next week. A cold front through western and central Alaska may also bring some precipitation in spots, but overall should be light and scattered in nature. In addition, strong gap winds could develop by Tuesday or Wednesday across some southern locations. The upper ridge lingering this weekend will continue to support above normal temperatures for much the state, with the greatest anomalies across the North Slope. While the North Slope (and parts of far eastern Alaska) should stay above normal even into next week, the rest of the state will experience a significant cooling trend as a strong cold front moves through. Anomalies across western and southwest Alaska could be 10 to 20 degrees below normal by next Thursday. Santorelli Hazards: - Heavy precipitation across portions of the Alaska Panhandle and mainland Alaska, Sat-Sun, Nov 19-Nov 20. 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