Mourning Warbler. Felipe Pimentel/Macaulay Library. eBird S36967529.

Continental Summary

Light to moderate flights becomes increasingly likely in the West and will feature White-throated Swift, Willow Flycatcher, Western Wood-Pewee, Eastern Kingbird, Swainson’s Thrush, MacGillivray’s Warbler, and Western Tanager, as spring migration winds down, while scattered moderate to heavy flights featuring Black Tern, Common Nighthawk, Chimney Swift, Yellow-billed Cuckoo, Acadian Flycatcher, Philadelphia Vireo, Cedar Waxwing, and Mourning Warbler will punctuate the migration scene in the East amidst unsettled conditions.

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.

We use data collected by eBird users help make more accurate forecasts. If you enjoy the predictions contained in these posts, please consider submitting your own bird sightings to eBird to even further improve the content. Every observation counts, whether it be a single bird at a feeder in your backyard, or an entire day spent in a national park. To get started with eBird, head on over to the site!

Please note that photographs and other digital media showing birds come from the Macaulay Library, which receives credit along with the photographer/observer in the media caption as part of a new initiative that allows public contribution, access and use of natural history media.

Finally, and new for Spring 2017, our friend Kyle Horton of the Radar Aeroecology Lab at Oklahoma University created a new set of images depicting spring bird movements in the Gulf of Mexico region as part of an analysis that he is leading as part of our ongoing collaboration. This feature appears in the Gulf Coast and Southeast region forecast.

Need a review of our definitions for regions, species on the move, and migration amounts? Please visit this link.

Quick Links to Regions

Upper Midwest and Northeast	Gulf Coast and Southeast
Great Plains	West

Upper Midwest and Northeast

A disturbance begins the weekend and ushers in a period of marginal migration conditions in many areas. Given the date, moderate to heavy flights may occur locally if wind conditions are calm or even from lightly opposing directions. Additionally, precipitation is forecast in some areas, creating a potential for concentrations and even local fallouts, so birders should watch where nocturnal migration and rain overlap; this is particularly true on Saturday and Sunday nights. The marginal and locally favorable migration conditions continue in many areas through the early part of the week, and moderate to heavy flights are likely in these areas. The likelihood of such movements shifts to the east as the work week continues as another low pressure center enters the region and starts to shut down movements in the Midwest and portions of the Great Lakes. The greatest intensity and extent of flights will come at the end of the period, as favorable conditions on Thursday night will spawn widespread moderate to locally very heavy flights.

Cedar Waxwing. Sheila Bremer/Macaulay Library. eBird S36737212.

Species on the Move

Beginning Arrivals What is this?

Peaking Arrivals

Beginning Departures

Ending Departures

Gulf Coast and Southeast

Moderate to heavy flights will occur in many areas of the region this weekend, with increasing potential for fallouts from Saturday through Tuesday. A frontal boundary and associated precipitation stalls in the Gulf Coast region, creating a scenario where birds arriving over the Gulf of Mexico may encounter rain. This potential is distributed along the Gulf Coast, and does not change significantly until Tuesday night as the frontal boundary shifts to the east. As this happens, conditions in the western Gulf of Mexico becomes highly unfavorable for migration, whereas conditions in the eastern Gulf and Florida in particular become quite good for moderate to heavy flights. Some of these flights may pile up along the east coast of Florida, creating a nice listening opportunity on Tuesday night to hear nocturnal flight calls. This frontal passage also has the potential to entrain yet more migrants into low pressure departing into the western North Atlantic, similar to previous events this spring, suggesting a watchful eye farther north in Canada. Most of the region is quiet by Wednesday night, with the exception of portions of inland Texas where moderate to heavy flights will occur. Thursday night sees these flights expand to many areas of the region away from the Florida Peninsula and southeastern coastal plain.

Yellow-billed Cuckoo. Aaron Evans/Macaulay Library. eBird S36930664.

Beginning Arrivals What is this?

Peaking Arrivals

Beginning Departures

Ending Departures

Weekly mean spring nocturnal migration activity and direction of movement in the Gulf of Mexico region for the week of 18-24 May, 1995 to 2015. Circular buffers around radar stations represent migration activity scaled to radar reflectivity (a measure of biological activity), with weekly activity represented by size scaled to the activity at KCRP Corpus Christi and seasonal activity represented by colors scaled to the most intense movements of the spring period (L: light, M: moderate, H:heavy); arrows represent mean track direction (a measure of the direction birds are traveling) derived from radial velocity.

Great Plains

A strong disturbance passing through the region keeps any favorable conditions for migration local and scattered. The northern Plains will see moderate to heavy flights on Friday, with more southerly locations experiencing mostly moderate flights on Sunday night. Once this system clears the region, unfavorable conditions build into most areas, with migration primarily light and local. In areas where winds are light, more intense movements may occur (e.g. in the northern Plains). The first significant change to this pattern occurs on Wednesday and Thursday nights, when marginal and locally favorable conditions return to the western Plains; so, too, will moderate to locally heavy flights. More intense flights are also likely by Thursday night in the southern Plains, as favorable migration conditions build as high pressure moves in to the south and east.

Black Tern. Brett Sandercock/Macaulay Library. eBird S36922549.

Species on the Move

Beginning Arrivals What is this?

Peaking Arrivals

Beginning Departures

Ending Departures

West

A quiet start to this late period will see scattered light movements mostly in the southern reaches of the West. More intense movements are likely in New Mexico and Colorado on Sunday night, as more favorable conditions for migration persist and intensify in those areas. By Tuesday night, the northern Rockies see action, with moderate flights in and to the east of these mountains. Wednesday sees the migration action return to areas farther south in the Rockies, but also some light to moderate flights scattered across the intermountain region and the Desert Southwest. By Thursday night, the most widespread favorable conditions occur, and despite the late date more widespread light to moderate flights are likely than at any other time during the forecast period. This is still particularly the case for the eastern reaches of the region, primarily to the east of the Rockies.

Eastern Kingbird. Harold Ziolkowski/Macaulay Library. eBird S36911859.

Species on the Move

Beginning Arrivals What is this?

Peaking Arrivals

Beginning Departures

Ending Departures

–––––––––––––––––––––––––––––––––––

Farnsworth and Van Doren