Et tu, Brute? More western species east . . .

Andrew Farnsworth The Cornell Lab Nov 09, 2012

The Weather Channel has taken to naming winter storms for the 2012-2013 winter season, and Brutus is at bat. This powerful storm is dumping heavy snow in parts of the Rockies, and the associated frontal boundary strongly demarcates much colder from very warm air. As the low tracks east, strong southerly and southwesterly flow prevails across much of the Plains through the Mississippi River valley north to the Great Lakes. These conditions are likely to produce a significant western flavor to late season bird migration, including the appearance of more Cave Swallows in the Great Lakes by the weekend. By early to midweek, perhaps 14-15 November, the frontal boundary passes into the Atlantic, bringing this western flavor and presumably Cave Swallows to coastal areas of the Northeast and Mid-Atlantic. Birders should watch not only for Cave Swallow but for the appearance of Ash-throated Flycatchers, Black-throated Gray Warbler, and Western Tanager among other species.

Winter Storm Brutus dropped heavy snow on portions of the Rockies and Northern Plains, but also created a warm air blast that will carry more typically western species into the Great Lakes and Northeast. This is a graphic from the Weather Channel’s continuing coverage of Winter Storm Brutus.