Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 705 PM EDT Thu Oct 10 2024 Valid 12Z Mon Oct 14 2024 - 12Z Fri Oct 18 2024 ***Gulf of Alaska storm continues to bring adverse weather for the southern coastal areas into Monday*** ...Overview and Guidance Evaluation/Preferences... A strong low pressure system is expected to be over the northern Gulf of Alaska to begin the forecast period Monday, although this is expected to steadily weaken going into the middle of the week. An arctic low situated north of Yukon Territory will also move away from the Arctic Coast early in the week. Meanwhile, a surface high will be stretched across the central Aleutians and into the Bering Sea region, although this will give way to more unsettled conditions as a low pressure system moves in from the west and likely crosses just south of the Aleutians. Low pressure will likely linger over the northern Gulf going into the end of the week, and a surface high over the Interior. The 12Z model guidance is in good overall agreement across the Alaska domain for the beginning of the week, and a general deterministic model compromise serves as a good starting point in the forecast process. Tuesday also features good agreement, with the one exception across the southern Gulf where the 12Z ECMWF spins up a stronger surface low off the British Columbia Coast. Given the lack of support from the AI guidance and the model consensus, this stronger solution is not currently favored. Looking ahead to the second half of the week, the CMC is a little slower with the arrival of the next low pressure system crossing south of the Aleutians, and weaker with the low over the northern Gulf, but still within the range of reasonable possibilities. The ensemble means were gradually increased to about 40-50% towards the end of the week. ...Weather/Hazards Highlights... The strong low pressure system that will be over the Gulf this weekend should still be impactful going into Monday, with windy conditions in northwest flow across the Alaska Peninsula, and continued onshore flow across the southeast Panhandle region. This will fuel additional rounds of rainfall across the region, although abating some in intensity compared to Sunday. Seas will continue to be quite rough with gale force winds remaining over the open waters. Several inches of rain is likely by early Tuesday near the coast from Cook Inlet to the southeast Panhandle, and heavy snow for the coastal mountain ranges. Lingering light to moderate snow is likely across the Brooks Range and the eastern North Slope after heavier snow over the weekend. Temperatures will be trending colder across most of the state as a cold front crosses and brings more of an arctic air mass to the region, with highs likely near or below freezing for most inland areas by the end of the week, and mid 30s to mid 40s near the southern coast. Some valley locations near the Brooks Range could have overnight lows near zero by Thursday and Friday. 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