A week of scattered light movement in the West will stand in stark contrast to moderate to heavy flights for much of the week in the East. Species on the move this week will include Tundra Swan, Gadwall, Bufflehead, Canvasback, Hooded Merganser, Sandhill Crane, Hermit Thrush, Snow Bunting, American Tree Sparrow, White-throated Sparrow, and White-crowned Sparrow.
Arrows show wind speed and direction (arrow points in the direction to which wind is blowing) 100 m above ground level. Areas with southerly winds are colored red; northerly winds colored blue. Accumulated precipitation (in 6 hour intervals) is green, outlined by white. Broadly speaking, areas of the map in red will experience conditions that are favorable for migration, and areas where red and green (and red and blue) intersect and overlap may experience migrant concentrations and fallouts as migrants interact with precipitation.
Generally marginal and unfavorable conditions settle in for most of the period in the West. Movements will be light to locally moderate, but scattered in space and time. The most extensive movements will occur toward the end of the period, when more favorable conditions from the southern California coast north and east through the Central Rockies will spawn light to moderate movements. Species on the move this week will include Bufflehead, Canvasback, Tundra Swan, Lesser Scaup, American Tree Sparrow, Bonaparte’s Gull, Greater Scaup, Horned Grebe, Dunlin, Thayer’s Gull, Northern Shrike, Rough-legged Hawk, Western Grebe, Herring Gull, and Ring-necked Duck.
Early weekend and early week pulses of moderate to heavy, and even locally very heavy, flights across the region will coincide with northerly flow and favorable conditions. And then, following a period of less favorable and generally more southerly flow, another low pressure system passes through the region to end the week. This late week movement will also feature moderate to heavy flights. Species on the move this week will include American Tree Sparrow, Gadwall, Sandhill Crane, Common Goldeneye, Bonaparte’s Gull, Snow Goose, Northern Pintail, Northern Shrike, Redhead, Dark-eyed Junco, Common Loon, Ring-billed Gull, Horned Grebe, Greater White-fronted Goose, and Ruddy Duck.
Upper Midwest and Northeast
Moderate to heavy flights, even very heavy in some locations (especially coastal locations), will be widespread across the region this weekend. These movements will include a high likelihood for morning flights after these significant nocturnal movements, so visit your favorite coastal or ridge line locations on Sunday and Monday mornings. Another substantial set of flights will occur early week, with moderate to heavy flights returning. This early week movement will include the interesting potential for fallouts and concentrations in coastal areas, as a disturbance offshore may meet migrants at or near the coast. These conditions continue for the duration of the period, making for particularly interesting birding from DelMarVa north into New England. Note that a strong area of low pressure is forecast to develop, making for the potential for interesting sea watching and near shore species displacement to some inland lakes. Species on the move this week will include Bufflehead, Snow Bunting, American Tree Sparrow, Hooded Merganser, Horned Grebe, Long-tailed Duck, Ruddy Duck, Ring-necked Duck, Fox Sparrow, Northern Shrike, Gadwall, Lesser Scaup, Common Goldeneye, Canvasback, and Rough-legged Hawk.
North Atlantic Oscillation Side Bar
In the past Octobers since the start of the BirdCast project, the team has discussed the promise of European vagrants appearing in North America a number of times (see this original posting from 2012 and the posting about Sandy that spawned it). Now, finding ourselves in the midst of October and surfing the inter web for potentially interesting meteorological tidbits, we find the past and coming weeks having two rather substantial low pressure systems (including the remains of Hurricane Gonzalo) moving across the Atlantic. Winds are forecast to be rather strong and from the east to the north of these systems as they spin way toward Europe, creating the potential bridge between the Palaearctic and Nearctic migration systems that may bring European visitors. Furthermore, the time is right for high pressure to establish itself over the North Atlantic, the so-called Greenland High, a rex block in the North Atlantic, or the “negative phase” of the North Atlantic Oscillation. Will someone in Northeastern North America be the lucky person to find a Yellow-browed Warbler, a bumper crop of which has appeared in Iceland already this October?
Gulf Coast and Southeast
Favorable conditions will spawn moderate to heavy flights, including some very heavy flights, in much of the region over the weekend and for much of the coming week. With the exception of Monday and Tuesday nights, when movements will be increasingly coastal and then scattered in distribution, respectively, much of the region will see continued large flights for the duration of the period. Species on the move this week will include Hermit Thrush, White-throated Sparrow, White-crowned Sparrow, Yellow-rumped Warbler, Dark-eyed Junco, Golden-crowned Kinglet, Gadwall, Swamp Sparrow, Song Sparrow, Vesper Sparrow, Lesser Scaup, Ruddy Duck, Savannah Sparrow, Ruby-crowned Kinglet, and Winter Wren.