Forecast and Analysis

Regional Migration Forecast: 21 – 28 March 2014

Andrew Farnsworth The Cornell Lab Mar 21, 2014

Continental Summary

A widespread movement in the West on Tuesday night will be followed by a similarly large-scale movement in the East on Thursday night. Species on the move this week will include Blue-winged Teal, Northern Pintail, Common Goldeneye, Common Loon, Double-crested Cormorant, Turkey Vulture, Swainson’s and Broad-winged Hawks, Ring-billed Gull, Scissor-tailed Flycatcher, Tree, Northern Rough-winged, Cliff, and Barn Swallows, Golden-crowned Kinglet, Brown Creeper, Brown Thrasher, Hooded and Prothonotary Warblers, Louisiana Waterthrush, American Tree and Chipping Sparrows, and Dark-eyed Junco.


Arrows show wind speed and direction 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 intersect and overlap may experience migrant concentrations and fallouts as migrants interact with precipitation.


Light to moderate movements kickoff the weekend in California and the Desert Southwest, some more scattered movements north and east through the central and eastern Rockies. These movements become increasingly scattered across the region through the weekend, with more extensive movements limited to the eastern Rockies by Sunday night. The week begins with a change, with more favorable conditions in the Pacific Northwest and portions of the Great Basin and Mojave Desert spawning light to moderate movements in those areas. These may include heavier movements in the Central Valley and points north along the Pacific Coast. Tuesday night sees widespread light to moderate movements across the region, with the potential for concentrations and fallouts in the immediate coastal vicinity of the Pacific Northwest. For the remainder of the period, conditions become increasingly less favorable and light to moderate movements will be restricted increasingly to the Desert Southwest and then eventually to local movements across the region on Thursday night. Species on the move this week will include Northern Pintail, Common Goldeneye, Turkey Vulture, Swainson’s Hawk, Mew, Ring-billed, and Herring Gulls, Pacific-slope Flycatcher, Western Kingbird, Bell’s and Warbling Vireos, Barn Swallow, Orange-crowned, Yellow and Black-throated Gray Warblers, Black-headed Grosbeak, and Scott’s, Bullock’s, and Hooded Orioles.

Great Plains

Unfavorable conditions are in place for much of the region to begin the period, with localized light to moderate movements likely only in the western Plains. The pattern improves slightly over the course of the weekend, with the Central Plains experiencing moderate movements by Sunday night. But it is not until Tuesday and Wednesday nights that widespread moderate and even heavy movements prevail across the region as favorable conditions finally arrive on the scene. The low pressure system and associated precipitation that follow will shut down movements by Thursday night, creating localized concentrations and fallouts where migrants meet precipitation (particularly in the southeastern Plains). Species on the move this week will include Snow, Ross’s and Cackling Geese, Blue-winged Teal, Common Goldeneye, Common Loon, Double-crested Cormorant, Great Egret, Turkey Vulture, Rough-legged Hawk, Upland and Baird’s Sandpipers, Greater Yellowlegs, Franklin’s and Ring-billed Gulls, Scissor-tailed Flycatcher, Tree, Northern Rough-winged, Cliff, and Barn Swallows, Blue-gray Gnatcatcher, Brown Thrasher, Louisiana Waterthrush, American Tree and Chipping Sparrows, and Dark-eyed Junco.

Upper Midwest and Northeast

Moderate movements, some of which may be locally heavy, will occur from the Central Mississippi River valley north and east through the Great Lakes and mid-Atlantic states to kick off the weekend. But most of the region sees migration shutdown for Saturday and Sunday as a passing low pressure system inhibits most movements. Note that some local light to moderate movements will be apparent in the eastern Great Lakes and northern New England on Saturday night. The early work week will see scattered light to moderate movements in the Great Lakes and Appalachia, shifting to New England by Tuesday and Wednesday. Wednesday night moderate to local heavy movements prevail from the western Great Lakes and western Ohio River valley south through the Central Mississippi River valley as favorable conditions move in. By Thursday night these conditions spread across much of the region as many areas see moderate movements, with some locally heavy movements scattered across many parts of the region. Species on the move this week will include Snow Goose, Tundra Swan, Blue-winged Teal, Northern Pintail, Common Goldeneye, Common Loon, Double-crested Cormorant, Snowy and Great Egrets, Osprey, Greater Yellowlegs, American Woodcock, Bonaparte’s Gull, Caspian Tern, Purple Martin, Tree, Northern Rough-winged, and Barn Swallows, Golden-crowned Kinglet, Brown Thrasher, Palm Warbler, and American Tree and Chipping Sparrows.

Gulf Coast and Southeast

Widespread moderate movements, and some heavy movements in Texas and portions of the Florida Peninsula and southeastern Coastal Plain, kick off the weekend as favorable conditions prevail. However, less favorable conditions restrict movements to immediate coastal areas by Saturday night, and then to the Florida Peninsula by Sunday night. Birders in the immediate coastal plains from Texas to Florida should watch closely the movements of precipitation on Saturday and Sunday, as trans-Gulf fallouts are likely where inbound migrants encounter precipitation. Monday and Tuesday will also likely hold the possibility for fallouts in the eastern Gulf Coast, as marginal and favorable conditions for departure from Mexico, Central America, and the Caribbean will allow migrants to move north into precipitation over the Gulf. The entire trans-Gulf system shuts down on Tuesday and portions of Wednesday as unfavorable conditions overspread the Gulf of Mexico. But as more favorable conditions return on Wednesday night, many areas west of the Mississippi River experience moderate movements; and Thursday night sees a return of widespread moderate and locally heavy movements across the region as favorable conditions prevail. Species on the move this week will include Ring-necked Duck, Hooded Merganser, Broad-winged Hawk, Upland Sandpiper, Ring-billed Gull, Chimney Swift, Ruby-throated Hummingbird, Yellow-bellied Sapsucker, Northern Flicker, Great Crested and Scissor-tailed Flycatcher, Eastern Phoebe, Eastern Kingbird, Cliff and Barn Swallows, Red-eyed  and Yellow-throated Vireos, Golden-crowned Kinglet, Brown Creeper, Hooded and Prothonotary Warblers, Louisiana Waterthrush, Rusty Blackbird, Orchard Oriole, Song and Fox Sparrows, and Dark-eyed Junco.

Special highlight

A fast-moving and strong low pressure system passing off the Atlantic Coast on Tuesday and moving rapidly north and east on Wednesday has the potential to transport early migrants in the southeastern US from the Caribbean offshore and far to the north of their intended destinations (e.g. into the Canadian Maritimes). We will monitor the evolution of this weather system and revisit this potential for spring overshoots early in the week to see how weather forecasts have changed.


Farnsworth and Van Doren