Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 659 PM EST Wed Feb 12 2025 Valid 12Z Sun Feb 16 2025 - 12Z Thu Feb 20 2025 ...Overview... An arctic upper low will initially be over northwestern Alaska on Sunday and this should slowly drift towards the northeast and lift north of the state by Tuesday. Meanwhile, a low will be weakening over the Gulf on Sunday, but a more active pattern emerges south of the Aleutians early to mid week with a couple additional low pressure system tracking east towards the Gulf region, providing onshore flow from Kodiak Island to the southeast Panhandle, with periods of rain and mountain snow expected. By the end of the forecast period Thursday, a weak ridge axis extends from western Canada to central Alaska, with generally above average temperatures expected across most of the state. ...Guidance Evaluation and Preferences... The model guidance initially shows some modest differences with the arctic low over northern Alaska early in the period, with the ECMWF/ECENS farther west than the GFS/GEFS/CMC solutions, with these differences increasing over time, leading to greater than average uncertainty for the northern half of the domain to begin next week. There is also growing uncertainty with the broad upper low south of the Aleutians and the shortwaves that pivot around it. The CMC was likely too far north with the surface lows that evolved when compared to the model consensus, so this was dropped by next Tuesday. The ensemble means were gradually increased to about 50-60% by the end of the forecast period, and some previous WPC continuity was maintained through Wednesday. ...Weather/Hazards Highlights... An upper low along with a surface low pressure system are forecast to track through the northeast Pacific this weekend, while an Arctic front should stall on the leading edge of high pressure strengthening over northwest Canada. These features will support modest precipitation for southern areas, including the Alaska Peninsula to South-central and Southeast Alaska. A few snow showers are possible farther north in areas of the Interior with a weak front in place. Into early-mid next week, low pressure systems tracking through the Aleutians are likely to produce rounds of precipitation and perhaps some gusty winds there. Southerly flow should allow for some precipitation eastward, leading to renewed rain/snow chances for the Alaska Peninsula to Southcentral areas Monday-Wednesday and perhaps into the Southeast. At this point, weather impacts look to generally remain below hazardous levels. Temperatures for most areas will gradually moderate closer to normal and then above normal as next week progresses given the increasing upper ridge pattern. 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