Alaska Extended Forecast Discussion National Weather Service College Park MD 721 PM EDT Wed Oct 15 2025 Valid 12Z Sun 19 Oct 2025 - 12Z Thu 23 Oct 2025 ...High winds and heavy precipitation for the Aleutians and Alaska Peninsula this weekend and possibly spreading eastward... ...Overview... A broad upper low is forecast to be in place atop eastern Siberia into the Bering Sea into early next week, with rounds of potentially impactful cyclones on its periphery. A large and deep surface low is forecast to pass near the Aleutians and Alaska Peninsula Sunday and bring heavy rain/precipitation and high winds. Most model guidance now shows that it should take an easterly track across the Gulf of Alaska Monday-Tuesday, perhaps bringing the heavy precipitation into Southcentral and Southeast Alaska. Another wave of upper troughing and a weaker surface low look to track near the Aleutians once again early next week, and then settle into the Gulf of Alaska while the broad cyclone aloft reorients a bit east into Bering Sea by midweek. ...Guidance Evaluation/Preferences... Most model guidance shows a notably strong surface low (generally in the 950s or 960s mb) impacting the Aleutians as the forecast period begins Sunday. At least multiple ECMWF, GFS, and UKMET runs show this, while the 12Z CMC finally had a stronger surface low (after multiple weak CMC runs) but well south of consensus. Later Sunday into Monday, most guidance has indicated a trend toward the low system moving east across the Gulf of Alaska, after models were split yesterday with some (like GFS runs) still directing the low more northeast toward Bristol Bay, like the best consensus from two days ago. The EC-AIFS seemed to be the first to catch on to the potential for an easterly rather than northeasterly track. The most recent AIFS is somewhat south of the EC/GFS though, allowing for less precipitation in Southcentral. In any case, the track over the Gulf is more agreeable now, with the low moving quickly east by Tuesday. A non-CMC model blend favoring the 12Z ECMWF and GFS and a bit of their ensemble means seemed best for this feature. Upstream, another surface low looks to track east from the southern tip of the Kamchatka Peninsula early next week. Models have this low's central pressure generally in the low 980s. There is model spread in the low position, with the ECMWF south of the Aleutians and GFS runs just to the north/on top of the islands Monday. With either track, the low looks to make it to Kodiak Island and the Gulf of Alaska by Tuesday and then persist there through Wednesday and Thursday. Meanwhile, the CMC low track is farther north and takes the low across the Bering Sea unlike the model and ensemble consensus, so the CMC was not favored for this feature either. After that, the ECMWF is alone in showing another surface low as deep as the upper 960s near 50N latitude Tuesday- Thursday. While not really affecting Alaska itself, it was in the forecast domain and thus reduced and then eliminated the ECMWF from the model blend by Days 7-8. Instead used a model blend favoring the ensemble means with a bit of GFS through the latter part of the period. ...Weather/Hazards Highlights... The Aleutians to the Alaska Peninsula can expect ample precipitation and high winds this weekend with the strong surface low. As the low tracks into the Gulf, precipitation will likely spread across Southcentral Sunday night into Monday, though there is a chance that the low track is far south enough that Southcentral does not see much. Precipitation should spread into Southeast Alaska (the Panhandle) regardless, beginning Monday. The second low will provide some moderate rain to the Aleutians and AKPen again on Sunday into Monday, likely reaching Southcentral and Southeast by Tuesday with moderate to heavy amounts. The slower-moving pattern by the middle of next week will be favorable for moisture streaming into Southeast Alaska for multiple rounds of precipitation next week. Thus will continue to monitor if this deserves a hazard area on the Day 3-7 Hazards chart, despite the high criteria for this time of year since the region can handle a lot of precipitation. Farther north across the Mainland, most areas should stay mainly dry early next week (after a few rain and snow showers early Sunday), until Tuesday and Wednesday when coverage of light precipitation may increase as energy aloft gets closer and funnels some weak moisture ahead of it. Temperature-wise, lower elevation areas of the Mainland will mostly be above average (especially for lows) through the period, with chillier temperatures in the Brooks and Alaska Ranges. The Lower Kuskokwim delta may cool to slightly below average by Wednesday-Thursday as energy aloft moves in. Southeast Alaska should be generally near average for temperatures in the 40s and low 50s. Tate 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