Area Forecast Discussion
Issued by NWS Anchorage, AK
Issued by NWS Anchorage, AK
586 FXAK68 PAFC 300213 AFDAFC Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 513 PM AKST Sat Nov 29 2025 .SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3: Tonight through Tuesday)... The much-advertised active pattern is taking shape this evening as a strong warm front associated with a very large North Pacific low begins to move up into the Gulf. A plume of moisture and lift has already overspread much of Southcentral out ahead of this front, with steady precipitation along the coast now starting to fill in quickly across the western Kenai Peninsula and Cook Inlet region as radar returns close in on the radar site, indicating a shift from mostly virga to precipitation reaching the ground. Temperatures aloft have stayed slightly cooler than model projections have indicated for this afternoon, as noted in the 00Z Anchorage sounding, capturing only a small layer above freezing between about 950 and 900 mb. This has helped keep precipitation type mostly snow with the initial arrival of precipitation making it to ground level. Meanwhile, much of the interior Kenai Peninsula has seen a mix of rain, snow and freezing rain already today, where temperatures aloft are warmer and where surface temperatures have been slow to rise above freezing. This has contributed to rather treacherous conditions along parts of the Sterling and Seward Highway corridor from Turnagain Pass south to Cooper Landing and Moose Pass, where the Winter Weather Advisory has been expanded to cover the ongoing rain and freezing rain event through this evening. Much of the forecast from tonight onwards continues to be marred with quite a lot of uncertainty regarding key details in the track and progression of a couple important features, as well as the behavior of low-level temperatures over the course of the next couple days. Even in the very near term for the overnight tonight, there is a large degree of spread in terms of how much precipitation is able to spill over the mountains into the Mat-Su, Anchorage and Kenai Peninsula. This seems to stem primarily from differences in the orientation of mid-level flow, with some solutions showing winds aloft stay a bit more southerly with less downslope drying off of the Kenai and Chugach Mountains. Other model solutions are keeping much of the corridor from Kenai to Wasilla/Palmer mostly dry through Sunday morning, with more true downslope/southeast flow dominating. There is also the question of when a transition over from snow/flurries to freezing rain might occur, which will entirely depend on how much warm advection can continue to push temperatures in the existing warm nose aloft higher through tonight into tomorrow. Bottom line, expect considerable variation in conditions across the region covered within the Winter Weather Advisory area. Conditions could vary from mostly rain with temperatures hovering at or just above freezing, to periods of freezing rain or light snow through Sunday morning. For Sunday morning onwards, discrepancies in model data continue to hamper forecast confidence. Still, the large scale pattern expectations still are about the same overall compared to what we were thinking yesterday to start off the week. The strong front will push a storm force barrier jet into the Gulf coast as it continues to lift north on Sunday, then rapidly weaken as it heads inland Sunday evening. Meanwhile, a compact low is expected to spin up ahead of a shortwave trough lifting nearly due north from the western Gulf as the front is moving onshore. By Sunday night, the upper level wave is expected to outrun the surface low near/over the southern Kenai Peninsula and continue to lift north into the western half of Southcentral. What all this will mean, in short, is quite a lot of continued precipitation for a good portion of both the coastline and the interior valleys from Sunday into Sunday night. Precipitation type during this window is where forecast confidence is the lowest. Models diverge quite a bit in terms of how much the continued onslaught of south to southeasterly flow will help push low-level temperatures above freezing, especially near Anchorage, the Mat- Su, and Copper Basin. As the upper level low lifts north, heavier precipitation will likely fill in between the western Kenai Peninsula and Mat-Su by Sunday afternoon. Currently, the forecast favors a scenario where most of this corridor ends up turning over to cold rain through Monday morning. However, a few inches of very slushy, wet snow is not out of the question for parts of Anchorage and the Mat Valley between Sunday and Monday if the colder model solutions for low-level temperatures come to fruition. Precipitation type troubles could also affect parts of the Copper Basin on Sunday, where a mix of snow, sleet and freezing rain could materialize if warmer air streaming in from the south is not able to scour out cold air in place quickly enough. From Monday to Tuesday, the upper trough will shift east towards the Yukon as another very transient upper ridge moves across Southcentral in between stronger storm systems. The next frontal system will quickly move in from the west during the day on Tuesday as another strong low moves up into the Bering Sea out west. At this time, it appears likely most locations near sea level will remain warm enough for mostly rain to fall with the arrival of this next front, with snow confined to mainly higher terrain as very warm air continues to spread north. Stay tuned for updates as we continue to follow this warm and active pattern into early next week. -AS && .SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days 1 through 3)... **Key Message: The Winter Storm Watch has been upgraded to a Winter Weather Advisory for the Kuskokwim Delta and Kuskokwim Valley from 1 AM Sunday to 5 AM Monday for up to 2" of snowfall and 0.2" of ice accumulation.** Satellite imagery is rather messy this afternoon as the first phase of our advertised winter storm is underway across Southwest Alaska. A complex low pressure system still spins south of the Aleutian Chain as a front continues to drive precipitation and warm air advection northward across the region. Surface observations and radar imagery already shows the first wave of rain/snow moving in a couple of hours ahead of schedule from Bristol Bay across the Dillingham area, with rain falling for King Salmon. Aloft, the flow across the Alaska Peninsula and Southwest Alaska is difluent downstream of a trough that has dug well southward over the North Pacific, which is aiding the front in providing synoptic forcing. From the surface to 925 mb, and then to 850 mb, guidance continues to indicate a strong veering wind profile, with easterly winds bringing in warmer air at the surface and a southeasterly wind doing the same aloft, partly due to a downsloping component in lee of the western Alaska Range and northern Aleutian Range. The warm nose effect and a just above freezing airmass at the surface for the Bristol Bay area has arrived, which has transitioned areas such as Dillingham from snow to rain. Areas under the Winter Weather Advisory will see precipitation move in this evening and overnight. This is where the cold air at the surface will be most established with a northerly reinforcing wind, so the idea is the leading edge of precipitation will be snow, and as the warm nose moves in, a transition to freezing rain will occur. As stated in the advisory, up to 2 inches of snow and 0.2" of ice accumulation is expected for these areas through Monday morning. There could be somewhat of a lull in activity Monday morning through Monday afternoon for the Kuskokwim Valley, though the YK Delta coast could still continue to lightly precipitate. Areas of freezing drizzle could linger through this time period as the upper flow again becomes difluent in nature as another North Pacific low races northward towards the eastern half of the Aleutian Chain with a slug of moisture ahead of its front. Late Monday afternoon is where the second phase of the event starts, and this one will be far more impactful. There will be significantly more QPF with this system, and wind profiles at the surface and aloft will closely resemble the first wave. With a stronger push with this front, a stronger surge of warmer air will be ushered in compared to the first wave, so places along Bristol Bay could very well warm into the 40s, with just below freezing temperatures holding on across the YK Delta and Valley locations. One note of caution is that cold air can be stubborn to erode from valleys as it is dense and wants to hug the surface, so freezing rain could be prolonged for these areas before a changeover to rain. With cold air not well established, the latent heat release from the freezing rain will help to further warm surface temperatures elsewhere. By Tuesday afternoon, significant ice accumulation of upwards of 0.5" is expected for the YK Delta coast, and upwards of 0.25-0.35" inland across the valleys is expected into the Sleetmute area. Please stay tuned to the forecast for further updates as the event continues to unfold. -AM && .LONG TERM FORECAST (Days 4 through 7 - Wednesday through Saturday)... The long term forecast starts with a large low in the Bering over the Central Aleutians. This low brings a large swath of precipitation to almost all of the Aleutians, the Pribilof Islands, and mainland Southwest Alaska. By this point in time, cooler air will filter into the Southwest mainland, allowing for freezing rain chances to diminish and for snowfall to be the predominant precipitation type. However, Bristol Bay will likely remain as rain or rain/snow for Wednesday. Gale force winds from the Central Aleutians to Kuskokwim Coast are possible. Southcentral Alaska will see lingering precipitation as the remnants of a front linger over the area. Thursday has a higher amount of uncertainty. In Southwest Alaska, it is likely that the mainland will see colder air move in as winds become northerly. This will likely bring in drier air, which would decrease chances for precipitation. The Bering could see the low weaken as it remains mostly stationary with light precipitation continuing. Some guidance has the low dissipating earlier, which would mean lower precipitation chances. Northwest winds will allow for elevated wind speeds in the Kuskokwim Delta (15 to 20 mph). Southcentral may have a break in active weather, with drier and cooler air moving in. Friday and Saturday are highly uncertain, but will likely see the continuation of decreasing temperatures due to an Arctic air mass dropping into Alaska. As for other features, some kind of a low may move into the Gulf of Alaska, allowing for higher precipitation chances and wind speeds, though it is uncertain exactly where this will set up. Southwest Alaska may see a break in active weather as a col sets up, allowing for lighter winds and lower chances for precipitation. -JAR && .AVIATION... PANC...VFR conditions with ceilings above 5000 ft and light northerly winds will persist through much of the TAF period. A wintry mix of precipitation will quickly move over the terminal this afternoon. A mix of snow, sleet, and freezing rain is possible initially, with ceilings and visibility dropping to MVFR, before the precipitation changes over to freezing rain. Temperatures gradually increase tonight, so lingering precipitation eventually turns over to all rain. A light glaze to a tenth of an inch of ice is possible. LLWS is also likely tonight through Monday morning as southeasterly wind aloft increase ahead of a front lifting north toward Prince William Sound. Ceilings and visibility improve back to VFR after midnight with diminishing precipitation. Another round of light precipitation is possible on Sunday, with more uncertain timing. This is expected to fall as a mix of rain and snow with minimal chances for freezing rain. Ceilings and visibility potentially drop back to MVFR during heavier precipitation, especially if snow. -TM/Quesada && $$