Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 732 PM EDT Sat Mar 18 2023 Valid 12Z Wed Mar 22 2023 - 12Z Sun Mar 26 2023 ...Overview/Guidance Evaluation/Predictability Assessment... A broad upper trough will be situated over the Bering Sea for the middle of the week, and the strong surface low is expected to be weakening as it slowly lifts northward across the Bering Strait. Shortwave energy pivoting around the southern periphery of this trough will induce a new surface low just south of the Alaska Peninsula and Kodiak Island that will become the next event to make weather headlines for southern Alaska. This low then drifts southeast through the end of the week and weakens. Looking ahead to next weekend, another organized low pressure system will likely approach the western Bering and eastern Siberia, and a separate low may also develop over the northern Gulf next Saturday. The model guidance initially has a good overall depiction of the synoptic scale pattern, and the latest CMC has come into better agreement with the low evolution over the Gulf and also the Bering, so more of it was incorporated compared to yesterday's forecast. The GFS begins to differ significantly by next weekend with a stronger surface high over western Alaska and a slower arrival of the next Bering Sea storm, so it was weighted less by Friday night and beyond. ...Weather/Hazard Highlights... Periods of moderate to heavy rain and heavy mountain snow are likely from Kodiak Island to the Kenai Peninsula on Wednesday as deep onshore flow ahead of the Gulf low advects copious Pacific moisture inland. This moisture of moisture then reaches locations farther east, including the southeast Panhandle, by Thursday although less intense. Strong winds are also possible for these coastal areas, mainly for the Kenai Peninsula and Kodiak Island where the pressure gradient will be tightest. Meanwhile, the winds should be slowly abating across northwestern Alaska as the first Bering Sea low weakens by midweek. Winds and precipitation could make a return to western portions of the state and the Aleutians depending on the eventual track of the next low pressure system entering the Bering late in the forecast period. Hamrick 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