Area Forecast Discussion
Issued by NWS Anchorage, AK
Issued by NWS Anchorage, AK
102 FXAK68 PAFC 240150 AFDAFC Southcentral and Southwest Alaska Forecast Discussion National Weather Service Anchorage AK 550 PM AKDT Sun Aug 23 2026 .SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3: Tonight through Wednesday)... The patchy fog that developed across parts of Southcentral this morning has since eroded thanks to drier air working in from the north along with plenty of sunshine and temperatures well into the 60s across much of the region. Gusty winds persist for a few coastal locations such as Seward and Whittier, due to a tighter pressure gradient between a low over the Gulf and a ridge of high pressure building in from the northwest. With mainly clear skies and weak winds overnight, low temperatures are likely to fall into low to mid 40s for many locations. Early morning low temperatures may even fall into the 30s for typically cooler locations, especially across the Copper River Valley. The added radiational cooling due to light winds and minimal cloud cover may also lead to a return of patchy fog Monday morning. Fog development, however, is likely to be less widespread than the previous morning due to the drier airmass working in along with today`s sunshine and warmer temperatures helping to dry things out. Monday will start off similar to today as the upper ridge shifts east into Southcentral. However, cloud cover will begin to increase as the day progresses, especially across the western half of the region. This will mark the beginning of our next rain-maker late Monday night through Wednesday. By Monday night, southwesterly flow with a deep fetch of moisture from the Pacific will develop out ahead of a extensive frontal system progressing across the Bering and western Mainland. This feature will extend into Southcentral as the ridge in place begins to slump south and lose amplitude. Several weak impulses riding with the strong southwesterlies will combine with warm, moist advection to generate light, steady rainfall spreading across the Kenai Peninsula and Mat-Su Valleys by late Monday night. More widespread rain will spread across nearly all of Southcentral on Tuesday as a potent, negatively-tilted shortwave trough riding along the frontal zone arrives from Southwest and produces deeper lift along the main moisture axis. As the trough and front move inland over the Interior and Southwest, a strong south-north pressure gradient will develop across Southcentral, supporting strong and gusty gap winds out of the Copper River Valley, Knik Valley and Turnagain Arm for much of the day on Tuesday. The highest rainfall amounts, on the order of 1 inch of more, will likely occur across the northern and east portions of the Susitna Valley, where the upslope flow helps to wring out additional moisture. Lesser amounts are likely for locations in the lee of the mountains and where the strongest gap winds occur. The precipitation will come an end from west to east through Wednesday morning, with the potential for showers to linger across the Talkeetna Mountains Wednesday afternoon and evening as a trailing shortwave moves along the Alaska Range. As the main weather system departs, expect another round of offshore flow and gusty winds for Whittier and Seward, similar to the winds observed today. -TM/AS && .SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days 1 through 3: Today through Wednesday)... An active pattern continues across the Bering Sea and Southwest Alaska through the middle of the week. A well-defined upper-low over the Bering continues to progress eastward today, with an associated shortwave and broad cyclonic flow spreading toward the Southwest coast. Increasing south to southwesterly flow ahead of this system will continue to transport moisture northward across the region, supporting periods of rain from the Aleutians and Bering into Southwest Alaska. Winds will also remain elevated across portions of the Bering and Aleutians as the pressure gradient tightens around the associated surface low. By Monday, the upper low shifts farther east toward Southwest Alaska while becoming increasingly elongated. Continued cyclonic flow and embedded shortwaves will maintain unsettled conditions across much of Southwest Alaska, with periods of rain and generally cloudy conditions expected. Farther west, precipitation becomes more showery across the Bering and Aleutians and gusty winds will also persist, particularly across the eastern Bering and along portions of the Southwest coast. The upper low continues eastward across Southwest Alaska Tuesday as the trough axis gradually moves inland. Showery conditions will linger beneath the cold pool aloft, though precipitation should become increasingly scattered from west to east as the system begins to pull away. Meanwhile, a transient area of weak ridging develops across the western and central Bering, allowing for a relative decrease in precipitation and winds for a time. Attention then turns westward again Wednesday as another upper- level low approaches the western Bering and Aleutians. Guidance shows some differences in the exact strength and track of this next system, but the overall pattern favors another increase in southerly flow, precipitation, and winds spreading into the western Aleutians and bering through the forecast period. Farther east, Southwest Alaska should see a relative break in the more widespread precipitation as the previous system departs, though lingering showers will remain possible. Overall, the pattern remains progressive through midweek, with only a brief relative lull between systems. Forecast confidence decreases somewhat by Wednesday as guidance differs on the strength and exact track of the next Bering low, though another round of increasing winds and precipitation across the Aleutians and Bering remains favorable. LM && .LONG TERM FORECAST (Days 4 through 7: Thursday through Sunday)... The long-term pattern will remain active across the Bering Sea as progressive west-to-east flow continues. Confidence remains high that a strong system off of the Kamchatka Coast Thursday will move to near Saint Lawrence Island by Friday. Strong southerly to southwesterly winds, small-craft to gale-force will move from the Bering to the Kuskokwim Delta Coast by Thursday afternoon, along with moderate to heavy rain with an atmospheric river accompanying this system. Moderate to heavy rain along the Pribilof Islands and portions of the Western and Central Aleutians will move to inland portions of Southwest Alaska through Thursday night and Friday morning. Light to moderate rain will also move across the Eastern Aleutians and Alaska Peninsula through Friday. Southcentral Alaska will eventually get in on the rain by Friday. Prior to this rain, Southcentral will have experienced a relatively nice and quiet Thursday. For now, it looks like the heaviest of the rain will fall across Southwest with this system with light to moderate rain across Southcentral. Pockets of heavier rain along the northern Gulf Coast are possible Friday night into Saturday. River levels across the Susitna Valley, such as the Yentna River at Lake Creek will have to be monitored closely with this system for potential flooding concerns. Steady rain across Southwest will taper to showers from west to east through the day on Saturday as the low tracks into Western Alaska from Norton Sound. Steady rain across Southcentral will move east to the Panhandle through Saturday as a low in the Gulf also moves east. Moisture wrapping around this low will allow rain to linger along the northern Gulf Coast into Sunday with scattered showers across the rest of Southcentral. Showers continue along the mountain ranges across Southwest for Sunday. Another system, weaker than the Friday system, moves into the western Bering by Saturday and spreads rain across the Western and Central Aleutians through Sunday morning. Rain also makes it to the Pribilof Islands Sunday morning as well. Winds with this system, as of now, are trending to be small-craft or less. && .AVIATION... PANC... High pressure will build in overnight, leading to the possibility of fog and low stratus. The chances of reduced visibilities are low due to overcast skies left behind by the parting trough. && $$