Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 700 PM EST Fri Jan 05 2024 Valid 12Z Wed Jan 10 2024 - 12Z Sun Jan 14 2024 ...Stormy conditions for the Aleutians and western Alaska... ...Overview... The western part of the state and the Aleutians will remain in an active wet and windy pattern as multiple low pressure systems move through the region. While there will be a mean trough over the eastern Pacific/Bering Sea to allow a couple of shortwaves/frontal systems to pass through the Aleutians and western part of the state, ridging will also be strengthening over the eastern two-thirds leading to warmer and drier conditions into next week. ...Guidance Evaluation/Preferences... While there was a small improvement noted yesterday for the beginning of the extended period, the latest runs have trended to a more diffuse starting point and maintained a not-so clustered evolution. The ensemble means were offset from their parent models, which did not help improve the forecast confidence. Although the exact track and details for each individual feature are uncertain, there continues to be consensus for increasing amplification of the ridge over the Mainland with a mean trough/multiple waves lifting through the eastern Pacific into the Aleutians/western part of Alaska. This pattern would favor warmer temperatures spreading across the Interior under the dome of high pressure in addition to mostly dry conditions. For the portions of the southern coast and northeast coast, but mainly the western and central Aleutians and western Mainland will have periods of strong wind/wind gusts along with moderate rain/snow. The WPC model composite maintained a sense of continuity by utilizing an initial blend of the ECWMF/GFS/CMC for Day 4 but then included EC ensemble means and GEFS means for Day 5 and beyond. ...Weather/Hazards Highlights... Before the start of the period, expect high winds across the Arctic Coast/North Slope region to persist into Friday and lead to periods of ground blizzard conditions. Then during the weekend the deep storm tracking northward through the Aleutians and Bering Sea will spread a broad area of high winds across those areas as well as portions of the mainland. Strongest winds over the mainland should be over parts of the Seward Peninsula and Lower Yukon/Lower Kuskokwim regions, with blizzard conditions possible there as well. The combination of the storm's leading front and a potential trailing wave/front will spread precipitation across and east from the Aleutians, with the most pronounced focus likely to be along the Alaska Peninsula and Kenai Peninsula during Saturday-Sunday. Meaningful totals may also be possible a little farther inland over the far southwestern mainland. What moisture reaches the southeast coast/Panhandle will produce much lighter precipitation, while fairly dry conditions should prevail over the Interior and North Slope. By next Tuesday-Wednesday another storm system may bring precipitation and brisk to strong winds to at least the Aleutians if not the Bering Sea and far western mainland as well. Monitor forecasts as details for this latter system become better resolved. Most of the state will see above to well above normal temperatures through the period, with highest anomalies likely over northern and western parts of the mainland. The primary exception will be over the eastern Interior, where negative anomalies should moderate after the weekend, and over the central-southern Panhandle with moderately below normal temperatures. Campbell 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