textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

Rainfall has tapered off this afternoon across the Kenai Peninsula, Anchorage, and much of the MatSu, with any remaining showers mainly staying over the terrain. As the upper level feature departs to the north and east, rain lingers across the northern Susitna and Copper Valleys through this evening as weak ridging builds in behind it. Expect a brief break in the rain with subsidence allowing for some sunshine across the Kenai Peninsula, with breaks in the cloud cover expected as far north as Anchorage and the MatSu through this evening. Winds persist through the evening hours before relaxing overnight tonight ahead of the next system.

For Thursday and Friday, another low pressure system will track from the Alaska Peninsula Thursday morning to over the Kenai Peninsula through Friday. This will bring another round of rain that will sweep slowly west to east as the system progresses. Models continue to remain in good agreement on the timing of this system with rain reaching the southern Kenai Peninsula mid to late Thursday morning and spreading north across Anchorage, the MatSu, and Prince William Sound by the afternoon. By Thursday night, the heaviest precipitation pushes east with the front across eastern Prince William Sound and the Copper Basin. The rest of Southcentral remains showery through Friday as the trough axis lifts north out of the northern Gulf across the region. While gap winds will likely come into some areas by Thursday afternoon, the farther south low track will lead to weaker winds than observed yesterday.

For the weekend, yet another low will round the southern edge of the main upper trough, amplifying the pattern and leading to another round of widespread rain.

LONG TERM FORECAST (Days 4 through 7: Sunday through Wednesday)

Very little change from the previous discussion. There is a strong signal in the global models of a slow moving, highly amplified, upper level trough consolidating along 165th west meridian and lingering across much of Alaska well into next workweek. Smaller scale details are less certain, especially with embedded shortwaves rounding the base of the trough and moving into the Gulf of Alaska, where moderate storm development is possible over the southern Bering Sea and northern Gulf. This pattern supports an extended unsettled stretch of daily rain chances region wide though precipitation will turn more widespread, organized and windier from the Southwest through Prince William Sound and Southcentral Alaska as moisture deepens and shifts northward. A multi-day heavy rainfall threat has been highlighted for those areas next week. The main forecast challenge through the long term is timing out shortwaves (which will drive periods of moderate rainfall) rotating around the large upper level trough complex that will anchor over the eastern Bering Sea.

Along the coastal waters, particularly the Gulf of Alaska and Southern Bering Sea, strengthening systems carry the potential for increasing winds and rougher seas. These conditions are likely to create hazardous marine environment for boating, commercial fishing and vessel operations, with heavier seas and gusty winds possible. Overall, the wetter and windier pattern across southern and coastal Alaska will require attention to accumulating rainfall impacts and marine hazards into early next week.

-DD/AM

AVIATION

PANC...VFR conditions will persist through most of the TAF period. Gusty south to southeast winds will slowly diminish this evening into tonight, but will likely return by around midday Thursday. Areas of rain and some lowering of ceilings are also likely by late Thursday morning ahead of a low approaching Southcentral from the Bristol Bay vicinity.