


Area Forecast Discussion
Issued by NWS Anchorage, AK
Issued by NWS Anchorage, AK
692 FXAK68 PAFC 171218 AFDAFC Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 418 AM AKDT Fri Oct 17 2025 .SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3: This afternoon through Sunday evening)... A negatively tilted trough is extending from the Susitna Valley southeastward into the northeastern Gulf this morning. This feature, coupled with a developing surface low near the entrance of Prince William Sound, is drawing moisture back over the Chugach Mountains and over Cook Inlet. The result is persistent low cloud cover and bands of light showers from north of Homer across the Anchorage Bowl and over the Talkeetna Mountains. Farther east, showers are also falling around Cordova and Valdez. The upper-level trough will lift northeast toward the Copper River Basin by mid to late morning, pushing the bulk of the moisture eastward, farther over the higher peaks of the Chugach and Talkeetna Mountains. However, as precipitation looks to wind down over northern Cook Inlet and Anchorage, a trailing vorticity lobe embedded in the weak westerly flow aloft will likely allow for enough lift for the redevelopment of showers into the afternoon for these locations. Precipitation will also become more widespread across the Copper River Basin by this afternoon as the downstream trough moves into the region. An upper level low then drives over Cook Inlet from Southwest Alaska late tonight into early Saturday. While the exact track and strength of this feature is still a bit uncertain, this feature will likely aid in the development of another area of showers from Cook Inlet into the Mat-Su Valleys by late this evening, aided again by moisture advecting westward from a surface trough over Prince William Sound. As the upper-level trough drops south into the western Gulf early Saturday morning, colder air will move in quickly behind it. Any lingering precipitation may fall in the form of snow across the Upper Hillside of Anchorage. As the trough and associated cold air advection moves southeast across the Gulf through Saturday, gusty gap winds increase out of Seward, Whittier, Thompson Pass, and the marine zone complex of Valdez. While gusty northern gap winds through Thompson Pass and Valdez Narrows persist into Sunday, northerly surface flow should inhabit really gusty conditions from getting into Whittier by then. A stronger storm that once trended farther north with more impacts for the Alaska Peninsula and possibly Kodiak Island for Sunday afternoon and evening, has now trended farther south, with less impacts for Kodiak Island with maybe some showers reaching the island from the storm`s northern flank by Sunday evening. TM/DAN && .SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days 1 through 3)... A deep vertically stacked low continues tracking eastward along the Aleutian Islands, with a frontal system pushing across the Islands the Bering Sea. A short-wave on the leading edge of the trough is leading to a band of rainfall ahead of the front, spreading across the Eastern Aleutians this morning before fizzling and moving south. Cold air advection moving into the Kuskokwim Delta may bring a transition to mixed rain/snow or possibly even all snow early this morning along the Kuskokwim Delta coast. This is mostly likely during periods of heavier precipitation as surface temperatures will hover just above freezing, though no snow accumulations are expected. Bethel and other inland locations won`t see the colder air arrive until at least midday, which favors precipitation remaining as mostly rain. A ridge moves over Southwest Alaska today, bringing quieter weather conditions. A plethora of short-waves will transit the Bering and Aleutians through tonight, with multiple compact lows crossing the Bering Sea. Confidence is low on the exact track of these features, but impacts will be fairly low and localized. The upper level pattern will once again amplify as we head through the weekend. However, there have been some large shifts in the models on storm track, trending much farther south with a North Pacific low this weekend. While uncertainty is still high, it looks like the bulk of precipitation and wind will remain south of the Alaska Peninsula as the low tracks eastward, with little to no impact on Bristol Bay and Southwest Alaska. Another deep low will approach the western Aleutians Sunday, with good model agreement and much better confidence in the track of this storm. && .LONG TERM FORECAST (Days 4 through 7)... Confidence is moderate that the general wind pattern through mid- week across the North Pacific and Gulf of Alaska turns more zonal. This west-east wind flow causes a deep North Pacific low to move eastward through the Gulf of Alaska early next week and into the Panhandle by mid-week. Multiple weak lows spin up off this parent low and slowly move into Prince William Sound toward the end of the week. As the parent low departs, weak ridging forms over the Gulf of Alaska. A main low moves through the Bering Sea and into the North Pacific mid- week. Cooler air filters into the Aleutians and Alaska Peninsula in the wake of this low`s departure. This low then progresses across the North Pacific into the Gulf of Alaska. As this low weakens and turns more stationary late next week, some models signal that it may take a northeastward path around the aforementioned weak ridge. This path would bring the low northward toward Kodiak Island/Kenai Peninsula. Though exact the placement of these two parent lows remains inconsistent, confidence remains moderate of zonal flow through mid-week. && .AVIATION... PANC...MVFR ceilings and light winds will persist through this morning with occasional light showers. MVFR visibilities are also possible at times with any heavier showers and mist. Showers may continue through the afternoon; however, any shower activity near the terminal is expected to become more scattered in nature with VFR ceilings at times. More widespread shower activity is then expected to redevelop over the terminal by late this evening, continuing into the overnight hours. Ceilings will again fall to MVFR with some scattered clouds below 1,000 ft possible. By mid- morning Saturday, winds turn northerly and increase as showers move east and ceilings improve. && $$