textproduct: Anchorage

SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)

A ridge of high pressure continues to build in over the Southern Mainland with multiple upper-level shortwaves rotating around the periphery of the ridge over the next few days. Relatively benign conditions are expected, overall; however there will be periodic cloud cover, along with scattered showers and isolated thunderstorms, mainly over the foothills of the higher terrain and across the Copper River Basin, to deal with each day. 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 and low clouds to eastern Kodiak Island this morning, with conditions drying out by later this afternoon as the low exits to the east.

For coastal locations, expect diurnally driven sea breezes each afternoon. Low-level marine stratus and areas of fog over parts of the northern Gulf may push closer to the coast beginning today, especially from Cordova to the entrance of Prince William Sound to Chenega. Patchy fog may also develop From Homer to Kenai during the early morning hours.

KM/TM

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...VFR conditions and light winds will persist. A light southerly wind will become more west-southwesterly today around 10 kt before shifting back to south for later this evening and into the overnight hours. There is a slight chance for a shower in the vicinity of the terminal this evening.