Alaska Extended Forecast Discussion NWS Weather Prediction Center College Park MD 554 PM EST Fri Mar 07 2025 Valid 12Z Tue Mar 11 2025 - 12Z Sat Mar 15 2025 ...Overview... A pair of lows near the coast of Southwest Alaska as well as in the Gulf will dissipate on Tuesday. The next sprawling North Pacific low will move along the south side of the Aleutians on Wednesday and Thursday, then into the western Gulf Friday and Saturday. Heavy precipitation on the north side of the low may impact Kodiak and Afognak Islands west to Katmai National Park. Meanwhile, a building polar high over the Arctic Ocean will increase the pressure gradient and winds around Point Hope and through the Bering Strait Thursday and Friday as troughing associated with the Aleutians low sets up across the Bering. ...Guidance Evaluation and Preferences... Most of the deterministic guidance (GFS/EC/CMC/UKMET) were in reasonable enough agreement with each other as regards the strength and track of the North Pacific low that will track south of the Aleutians and into the Gulf from Wednesday into next weekend. Given that is the only feature of significant import, the model preferences were primarily tailored to the handling of that low. The only other feature of note is an Arctic High over the Chukchi Sea that will be increasing the winds around Point Hope and the Bering Strait from Thursday through Saturday. Terrain will be a substantial factor in the localized nature of these high winds, and the model handling of the high is good. The lows both near the coast of Southwest Alaska and the one in the Gulf both on Tuesday will both dissipate through the day on Tuesday, so model handling of those lows, while not good, ultimately did not have any impact on the forecast overall. Given all of the above and the better-than-normal handling of the low by the deterministics, a larger than normal share of the deterministics was left in the model blend used for the maps through Day 8/Saturday, to offset the tendency in the ensembles to wash out stronger features. On approach to the Aleutians, the CMC was the northern and western outlier, trying to depict weaker secondary lows forming and then dissipating/absorbing into the parent low, so its influence was diminished, and the EC was about 5-10 mb stronger/deeper with the low than the others, so it too was reduced. ...Weather/Hazards Highlights... There are no significant hazards forecast for Alaska through next Saturday/Day 8. Threats we are watching include a sprawling North Pacific low moving along the Aleutians Wednesday and Thursday and into the Gulf Friday and Saturday that will produce low elevation rain and mountain snow, which may be heavy at times around Kodiak and into Katmai National Park Thursday through Saturday. Localized gale force winds are likely through the gaps in the Alaska Peninsula, Shelikof Strait, and across much of the northern Gulf, as well as some of the inner channels in the Panhandle. Elsewhwere, a strong polar high will build across the North Slope late week, which will increase the winds through the Bering Strait as well as around Point Hope and portions of the Chukchi Sea. Temperature-wise, the coldest conditions will be across northern and eastern Alaska, where surface high pressure stuck across the Yukon and Nunavut will keep conditions tranquil, with cold air damming keeping the valleys cold. The coldest conditions are expected with the building of the polar high north of the Brooks Range, where lows Friday night could approach 30 below. Wegman 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