


Area Forecast Discussion
Issued by NWS Anchorage, AK
Issued by NWS Anchorage, AK
518 FXAK68 PAFC 151333 AFDAFC Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 533 AM AKDT Wed Oct 15 2025 .SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3: Tonight through Friday)... A transient upper-level ridge is quickly exiting the region this morning as a potent upper-level trough and occluding surface front drive into the western Gulf ahead of a strong surface low situated over the eastern half of the Aleutian Islands. Clouds are quickly on the increase across the region as these features move east and the ridge departs. Areas of fog have developed across portions of the Copper River Valley overnight, but are expected to scour out by mid morning. Temperatures there were falling through the 30s for many locations but have stabilized as the increasing cloud cover hampers any further radiational cooling. The aforementioned front will move over Kodiak Island later this morning, then into the northern Gulf by the afternoon hours. A corridor of gale force winds will intensify to storm force as the front approaches both Kennedy Entrance and the northern Gulf coast as a barrier jet forms ahead of the boundary. These strong easterlies will affect the Barren Islands briefly on Wednesday afternoon before the front continues to the north. A secondary corridor of storm force winds will move south of Prince William Sound Wednesday afternoon into Wednesday night before winds rapidly weaken as the front moves onshore. Aside from the marine impacts, strong easterly winds are also expected to move up into the Kenai Mountains and Turnagain Arm, but a sharp down-inlet gradient developing ahead of the front will prevent strong winds from coming into Anchorage. However, fairly strong winds gusting up to 40 mph will still pick up across the Mat Valley out of the northeast Wednesday afternoon through Wednesday night thanks to the same northeast to southwest pressure gradient picking up ahead of the front. In terms of rainfall, the heaviest rain will shift from Kodiak on Wednesday morning into the eastern Kenai Peninsula and Prince William Sound Wednesday afternoon, with storm total accumulations from Cordova to Whittier and Portage on the order of 2 to 3 inches or rain. Most areas in the lee of the mountains will stay relatively dry through Wednesday night due to the strong cross-barrier flow moving in ahead of the front; however, rain showers will eventually make it to these locations by late Wednesday night or Thursday morning as both the surface front and flow aloft weaken. Higher elevations such as Thompson Pass and Tahneta Pass/Eureka will likely see some accumulating snow, around 1 to 3 inches, before a changeover to a rain/snow mix or all rain by Wednesday night. By early Thursday, the parent low currently moving over the Aleutians will drift northeast into the Gulf and move south of Prince William Sound by Thursday evening. Winds along the coastline will mostly subside as winds up to gale force south of the low shift from southerly to westerly over the open Gulf waters. Steadier periods of rain will give way to scattered showers as multiple weak waves rotating around the low pinwheel into Southcentral. Unsettled and showery conditions will persist into Friday as the low continues to degrade over the northern Gulf and as a cooler air mass begins to filter in from the west across the Alaska Range. -AS/TM && .SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days 1 through 3/Tonight through Friday)... Morning satellite imagery reveals a large and mature ~965 mb occluded low located just south of Akutan and Unalaska. Overlaid surface analysis shows surface troughing/its front situated just east of the Pribilof Islands, stretching southeastward across the Alaska Peninsula, and farther southward into the North Pacific. According to surface observations, winds have been sustained at gale force and gusting upwards of 35-45+ kts through favored bays and passes of the Alaska Peninsula and northwestward across Bristol Bay. Saint Paul has also seen wind gusts over 40 kts this morning, which is evidence that this low is over-performing wind wise as models are not really capturing/initializing its associated winds that well, though the NAM/GFS LAMP MOS seems closer to the ballpark of what is being observed. Also of note, a sting jet is present on the back side of the low with drier air and colder air advecting into the circulation. This has resulted in gale force northwesterly winds moving across the Central Aleutians in the wake of the low. Short range model guidance shows that the front will take little time traversing this region, with the front pivoting inland across the coastal Southwest Alaska zones this morning. The front looks to also reorient itself more east-west, which means that easterly Kamishak gap winds will become more favorable and begin to pick up in intensity later this morning. Near-term QPF amounts look to be on the order of 0.5-1" for the Eastern Aleutians/Alaska Peninsula (with locally higher amounts of 2"+ for the windward slopes of the southern Alaska Peninsula due to orographic lift), up to 0.25" across the Kuskokwim Valley, and 0.5-1" seeming likely for the immediate coastal Southwest areas, including the Kuskokwim Delta region. Easterly to east-southeasterly winds are really not a great setup to see coastal flooding for this region just hit very hard by the previous storm. However, we could see elevated water levels during higher tide cycles. Behind this storm system, 850 mb temperature anomalies from the global models are signaling an unseasonably cool airmass moving across much of the Bering and Aleutians through the end of the week, with a near freezing to subfreezing airmass in place for Southwest Alaska by Thursday/Friday. Aloft, the synoptic pattern continues to remain unsettled through the short term and beyond, with the upper level low associated with the aforementioned occluded low moving out of the region and into the Gulf Wednesday afternoon. The upstream 500 mb dynamic pattern has a couple of shortwaves rotating over the Bering, with a more robust wave located south of the Western Aleutians Thursday morning. Models agree that this upper level support will favor weak cyclogenesis at the surface south of the Aleutian chain heading into Thursday afternoon. Looking forward to Day 4 (Saturday), most of the global models are in loose agreement of another gale force low making its way from the North Pacific and generally northeastward towards the Aleutian Chain, but differ on placement, timing, and strength. All said, confidence remains lower than average for a potential storm system for this weekend. -AM && .LONG TERM FORECAST (Days 4 through 7/Saturday through Tuesday)... Starting with this weekend, all guidance points toward a continued stormy pattern, with a highly amplified and strong subtropical jet stream. However, there is a huge spread in operational model guidance and poor run-to-run continuity with the handling of individual storm systems. The hemispheric flow does look progressive and favors a west to east storm track across the southern tier of Alaska from the Aleutians and southern Bering Sea to Bristol Bay and the Alaska Peninsula to the Gulf of Alaska and north Gulf coast/Prince William Sound. These regions would be favored for strong winds and heavy precipitation. Areas further north would see lesser impacts from wind and precipitation. By early next week, models indicate the jet stream becoming more zonal and the center of the long-wave trough shifting just a bit eastward (with some ridging indicated upstream over the Asian continent). This could bring an end to this period of intense storms that we have been experiencing over the past week. -SEB && .AVIATION... PANC...Light northerly winds intensify through the day with the approach of a strong front and low pressure system. Ceilings begin VFR above 5000 ft. Low level wind shear is possible as winds will be southeasterly aloft through the morning. By this afternoon, down inlet pressure gradients intensify enough for wind shear to abate below 2000 ft. Winds could gust as high as 25 kt this afternoon out of the north to northeast. Late this evening, the front lifts across the terminal, allowing winds to diminish and potentially bringing ceilings below 5000 ft with light rain showers. However, there is only a low probability for MVFR ceilings. Light rain shower potential continues into Thursday morning with light northerly winds. Quesada && $$