textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

Ridging builds in over Southcentral, with a series of shortwaves cycling around the periphery of the ridge over the next few days. Overall, relatively benign conditions are expected. Partly cloudy skies and light rain showers, especially along terrain and upslope areas, will persist through midweek. The low currently sitting south of the Alaska Peninsula will slowly make its way across the Gulf of Alaska and weaken as it moves towards Yakutat. An associated front is bringing persistent light rainfall to eastern Kodiak Island today and tomorrow morning, with conditions drying out as the low exits to the east.

As the low moves east, and ridging builds in from Canada, rounds of easterly waves will trek across Southcentral, bringing warmer air and producing a more unstable atmosphere. The dominant flow will be northerly, offshore, allowing for more seasonal and diurnally driven sea breezes for coastal locations.

KM

LONG TERM FORECAST (Days 4 through 7: Friday through Monday)

Expect unsettled weather late this week into early next week, though no major hazards are anticipated at this time. As an Arctic upper low and a North Pacific low converge on Southern Alaska, the main concerns will be (a) thunderstorm potential in the interior and (b) steady rain along the Gulf coast, with some question of how much moisture will make it inland.

Friday begins with a bit of a col over Southern Alaska due to one low approaching Southwest Alaska and another departing into Southeast Alaska; meanwhile, ridges extend over interior Alaska/Canada and the Bering Sea. As the low moves into Southwest Alaska through the weekend, increasing vorticity (combined with diurnal heating under a surface ridge) will likely spur afternoon/evening thunderstorms across the Southcentral interior. Southwest Alaska may also see thunderstorms earlier in the period, but the approaching North Pacific low may bring enough cloud cover and rain to stabilize the atmosphere as early as Saturday afternoon. This will depend on the track of the moisture stream, which is a bit uncertain at this time. Deterministic models show precipitation moving in over the weekend between a line extending from Bethel to Sand Point, and another line extending from about Glennallen to Valdez; which areas will see the most precipitation remains uncertain at this time, but there's enough consensus to suggest overcast and perhaps even rainy conditions for much of the Southern Mainland by the latter half of the weekend and into early next week.

For the Bering Sea and Aleutian Islands, the ridge will remain the dominant weather influence. While fronts will nudge into the Western Aleutians (Attu to Amchitka) early on Friday and on then again on Monday, models suggest the ridge will remain strong enough to keep these fronts from progressing much into the Bering Sea. As such, much of the Bering Sea will likely see overcast skies and areas of fog due to subsidence under the ridge.

-KC

AVIATION

PANC...Variable winds become light and southerly from 08Z Tuesday through 18Z Tuesday. A more westerly wind will persist through Tuesday evening with speeds near 10 knots.