Update 24 Sep 2007: Seen on the 22nd was Gambell's 3rd Siberian Accentor, 4th Dusky Warbler, and 6th Little Bunting of the season; while St Paul, Pribilofs turned up their 2nd Siberian Accentor and first Pechora Pipit of the season. And the big news, adding some weight to my tenuous connection - a Common Rosefinch at Southeast Farallon Island, California - the first ever in North America away from western Alaska.It's been an above-average fall for Asian birds in Alaska. The tiny "oasis" of Gambell, on Saint Lawrence Island, has been well-watched by Paul Lehman and others for each of the last 10 or so falls, so I think it's safe to say that Gambell has more rare birds this fall and not just better coverage. Of course, there could still be other explanations besides more vagrants coming to Alaska - local weather that concentrates or keeps birds at the point or in some way makes them easier to find, the same observers with more experience getting better at finding and identifying rarities, random chance....
The Pribilofs (Saint Paul Island) have had less consistent coverage, and with more habitat vagrant landbirds can be harder to find there (relying more on chance), but this has been a good season compared to the last several years, especially considering the Brown Hawk-Owl last month.
Sky Lark - up to 6 at Pribilofs
Brown Shrike - 1 at Gambell (about 8 NA records)
Siberian Accentors - 2 at Gambell, 1 at Pribilofs (about 25 NA records)
Red-flanked Bluetail - 1 at Pribilofs
Dusky Warbler - 3 at Gambell (now about 20 NA records)
Willow Warbler - 3 at Gambell (bringing the total to 4 NA records, all from Gambell)
Yellow-browed Warbler - 1 at Pribilofs (now 4 NA records, the other three from Gambell in he last few years)
Olive-backed Pipit - 1 at Pribilofs
Pechora Pipit - 2 at Gambell (about 30? NA records)
Pallas's Bunting - 1 at Gambell (6th NA record)
*Yellow-browed Bunting - 1 at Gambell, first NA record
Little Buntings 4 or 5 at Gambell, 1 at Pribilofs (now about 20 total NA records)
Common Rosefinch - 1 at Gambell (about 20 NA records?)
Most birders have little chance of getting to Gambell in the fall, so these reports seem unreal. But if you like to be optimistic, an unprecedented three Arctic Warblers in southern California last week could start to look like a pattern of Asian vagrants. Unprecedented things seem to happen in California pretty regularly... but the distance from Gambell to southern California is about the same as the distance from Gambell to Michigan.
OK, I admit it is a bit of a stretch to link the CA Arctic Warblers to the Siberian birds at Gambell, but birders all over North America would do well to recall past records of things like Siberian Accentors in the northern Rocky Mountains, Siberian Flycatcher in Bermuda, Brown Shrike in Nova Scotia, Siberian Stonechat in New Brunswick, and Siberian Rubythroat in Ontario.
Get to know your local patch, keep an open mind, and go out there and look. There's no telling what might turn up.