Forecast and Analysis

Regional Migration Analysis: 18-25 April 2014

Andrew Farnsworth The Cornell Lab Apr 25, 2014

Continental Summary

Widespread light to moderate movements occurred early in the period in the West, while a major pulse of moderate to heavy movements occurred late in the week in the Southeast. Species on the move this week included Semipalmated Plover, Spotted Sandpiper, Wilson’s Phalarope, Chimney Swift, Warbling Vireo, House Wren, a suite of warblers, Chipping, Clay-colored, and Lark Sparrows, Baltimore Oriole, and Dickcissel.


Light to moderate, and in places locally heavy, movements were widespread to begin the period, particularly in the Desert Southwest and California. These continued into the beginning of the week in the southern portions of the region, while the northern portions saw movements shut down by widespread precipitation. This pattern persisted through the remainder of the week, with most movements apparent in central and southern California and the Desert Southwest. Species on the move this week included Semipalmated Plover, Spotted Sandpiper, Least Sandpiper, Western Sandpiper, Wilson’s Phalarope, Vaux’s Swift, Brown-crested Flycatcher, Western Kingbird, Warbling Vireo, Yellow Warbler, Wilson’s Warbler, Yellow-breasted Chat, Western Tanager, and Lazuli Bunting.

Great Plains

Light to moderate movements were scattered across the region during the first half of the period, delimited largely by those places not affected by the unfavorable conditions associated with passing low pressure centers that began and ended the weekend. Moderate movements persisted along the border to begin the week, expanding by Tuesday night over much of the eastern and southern portions of the region. But an intense line of storms associated with a passing disturbance moved through the central Plains on Wednesday night, shutting down most movements in the Dakotas and western Nebraska. As this system passed, it eventually shut down most movements across the entirety of the region by Thursday night, with only local and scattered light to moderate movements primarily in the central and southern Plains. Species on the move this week included Semipalmated Plover, Spotted Sandpiper, Willet, Lesser Yellowlegs, Wilson’s Phalarope, Western and Eastern Kingbirds, Warbling Vireo, House Wren, Orange-crowned and Yellow-rumped Warblers, Chipping, Clay-colored, and Lark Sparrows, and Baltimore Oriole.

Upper Midwest and Northeast

Primarily light and locally moderate movements kicked off the weekend, beginning in the Great Lakes and then expanding in extent through the remainder of the region over the course of the weekend. As a weak frontal boundary moved across the Mississippi River valley and through the Great Lakes, migration shut down behind the boundary while light to locally moderate movements continued ahead of it. This system’s passage clear the decks by Tuesday night, with the exception of scattered light to moderate movements in the upper Mississippi River valley. To end the period, favorable conditions slowly built back into the region in advance of a strong front boundary moving into and through the Mississippi River valley, with a pulse of light to moderate movements in the Appalachians and mid-Atlantic states by Thursday night. Species on the move this week included Chimney Swift, Great Crested Flycatcher, Blue-headed, Warbling, and Red-eyed Vireos, House Wren, Blue-gray Gnatcatcher, Wood Thrush, Black-and-white, Orange-crowned, and Nashville Warblers, Common Yellowthroat, Yellow, Yellow-rumped, and Black-throated Green Warblers.

Gulf Coast and Southeast

As low pressure and precipitation departed through the Southeast, light to moderate movements gradually filled in over areas west of the Mississippi. These movements expanded to the east as more favorable conditions built in as high pressure moved toward Florida, and some of the movements were heavy by Sunday night. These relatively widespread moderate and locally heavy movements continued over the course of the week, intensifying to a large take off on Thursday night when many radars were showing heavy movements from Texas to central Florida. Species on the move this week included Mississippi Kite, Common Nighthawk, Eastern Wood-Pewee, Least Flycatcher, Veery, Swainson’s andWood Thrush, American Redstart, Magnolia, Bay-breasted, Yellow, and Blackpoll Warblers, Yellow-breasted Chat, Rose-breasted Grosbeak, and Dickcissel.