Forecast and Analysis

Regional Migration Forecast: 24-31 October 2014

Andrew Farnsworth The Cornell Lab Oct 24, 2014

Continental Summary

Moderate to heavy movements occur in several pulses this week, though primarily at more local than regional scales, as storm systems exit the Northeast over the weekend and pass through the Great Plains and Upper Midwest over the course of the week. Species on the move this week will include Lesser Scaup, Bufflehead, Common Goldeneye, Long-tailed Duck, Red-breasted Merganser, Hooded Merganser, Bonaparte’s Gull, Hermit Thrush, Snow Bunting, American Tree Sparrow, and Dark-eyed Junco.

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.


Unfavorable conditions begin and end the week, keeping most migrants on the ground for the start and end of the forecast period. But two low pressure systems are forecast to move through the region, and these will bring increasingly marginal and finally favorable conditions by Wednesday and Thursday nights. Leading up to these nights, movements will be most scattered light to moderate, reaching their greatest extents and intensities, primarily light to moderate flights, by Wednesday and Thursday. Generally, as the migration season for most passerines wanes, waterfowl step up and are much more prominent. Species on the move this week will include Bufflehead, Red-breasted Merganser, Bonaparte’s Gull, Hooded Merganser, Lesser Scaup, Canvasback, Tundra Swan, Long-tailed Duck, Black Scoter, Common Loon, American Tree Sparrow, Rough-legged Hawk, Greater Scaup, Surf Scoter, and Common Goldeneye.

Great Plains

Marginal and locally favorable conditions are pervasive across the region through at least the middle of the week. Where conditions allow, light to moderate and locally heavy movements will occur. Note that Tuesday and Wednesday may produce interesting movements, possibly local concentrations of birds, as migrants in favorable wind conditions fly into precipitation and face potential grounding conditions. Not until the end of the forecast period do truly favorable conditions arrive that are widespread. On Thursday night widespread light to moderate movements will occur, with some heavy and possibly local very heavy movements. This night will surely represent one of the last large movements of the fall of both landbirds and waterbirds. Species on the move this week will include Hooded Merganser, American Tree Sparrow, Lesser Scaup, Common Loon, Red-breasted Merganser, Lapland Longspur, Canvasback, Bonaparte’s Gull, Fox Sparrow, Greater Scaup, Ring-necked Duck, Common Goldeneye, Redhead, Dark-eyed Junco, and Ruddy Duck.

Upper Midwest and Northeast

Increasingly favorable conditions build into the region over the weekend, as widespread moderate to heavy movements follow. Note that strong winds in coastal areas will cause morning flights in appropriate areas, particularly on Sunday and Monday mornings. The beginning of the work week sees a return of southerly flow and the movement of a strong low pressure system across the region. In advance of this system movements will decrease in extent and intensity quite rapidly. This system does not completely clear the region during this forecast period, and marginal to locally favorable conditions end the week as a result with requisite moderate flights where conditions will allow. Species on the move this week will include Bufflehead, Snow Bunting, Hooded Merganser, Common Goldeneye, Long-tailed Duck, Red-breasted Merganser, Common Loon, Horned Grebe, Lesser Scaup, Red Phalarope, Ring-necked Duck, Cave Swallow (yes this species is in the mix, with strong low pressure potentially moving birds from where they are now into the Northeast as has occurred in past years), Common Redpoll, Black Scoter, and Bonaparte’s Gull.

Gulf Coast and Southeast

Moderate to locally heavy movements that begin the period in the southeast give way to increasingly light movements across the region over the weekend and into next week as southerly flow returns. The week continues with mostly unfavorable and locally marginal and favorable conditions, and migration will be scattered and mostly light to moderate. Not until the end of the week, probably late on Thursday or early on Friday, do conditions for larger scale moderate to heavy movements return. Species on the move this week will include Hermit Thrush, Lesser Scaup, Dark-eyed Junco, Ring-necked Duck, Hooded Merganser, Chipping Sparrow, Gadwall, White-crowned Sparrow, Common Loon, White-throated Sparrow, American Pipit, Vesper Sparrow, Redhead, Snow Goose, and Canvasback.