Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 639 PM EST Sun Dec 15 2024 Valid 12Z Thu Dec 19 2024 - 12Z Mon Dec 23 2024 ***Multiple surface lows over the Gulf and North Pacific to produce hazardous maritime conditions late in the week and into the weekend*** ...Overview/Guidance Evaluation/Preferences... A very active weather pattern will be in place across the North Pacific and extending into the Gulf of Alaska for most of the upcoming forecast period beginning on Thursday. A strong surface low is expected to track towards the northwest and in the general direction of Kodiak Island late in the week, and weakening as it approaches the coast. The UKMET and CMC are generally faster with this low. A second low will likely follow this, although the guidance greatly differs on the strength of it, with the ECMWF quite a bit stronger with it compared to the much weaker GFS. The third and probably most powerful low pressure system develops over the southern Gulf going into Sunday and likely gains latitude going into Monday as the upper ridge axis situated over western Canada blocks its eastward progress. Both the EC and GEFS means are in good overall agreement with the low being about a few hundred miles south of the Kenai Peninsula by Monday morning, but the deterministic guidance is generally south and east of that position. There is a trend for a stronger system, with the guidance into the 950s and low 960s. ...Weather/Hazards Highlights... There will likely be a increase in southeasterly flow from the northeast Pacific into southern Alaska, resulting in increasingly cloudy skies statewide and a gradual warm up for many areas, which will be most pronounced in the southern half of the state and slowest across northern and eastern portions of Alaska. Gale to storm force winds are likely across the Gulf of Alaska and near the Bering Strait with the approach of the storm systems noted earlier, especially with the storm in the Gulf about a week away. Daily precipitation near south-central Alaska should be about 0.5 to 1.5 inches of QPF per day in windward coastal terrain, though a spike in amounts appears more likely going into next weekend with a potential atmospheric river event developing. Hamrick Additional 3-7 Day Hazard Information can be found on the WPC medium range hazards outlook chart at: The WPC Hazards Outline depicts these threats. 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