Bank Swallow. Noah Strycker/Macaulay Library. eBird S38680296.

Continental Summary

Moderate movements featuring Northern Shoveler, Killdeer, Belted Kingfisher, Warbling Vireo, MacGillivray’s Warbler, Yellow Warbler, and Western Tanager are likely in many areas of the West, while the East will see scattered moderate to heavy pulses that feature Blue-winged Teal, Common Nighthawk, Least Flycatcher, Eastern Wood-Pewee, Yellow Warbler, Chestnut-sided Warbler, and Summer Tanager. The dangerous Hurricane Harvey will bring typical Gulf of Mexico bound seabirds and near shore species to inland locations from Texas and Louisiana to Arkansas over the course of the week.

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 blue will experience conditions that are favorable for migration, and areas where blue and green (and red and blue) intersect and overlap may experience migrant concentrations and fallouts as migrants interact with precipitation.

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Quick Links to Regions

Upper Midwest and Northeast	Gulf Coast and Southeast
Great Plains	West

Upper Midwest and Northeast

Moderate to heavy flights are likely in many areas of the region for the weekend, although the extent of these flights will become increasingly restricted to coastal areas and highly localized mountainous areas by Sunday. However, a new low pressure center moving east through the Upper Mississippi River Valley will bring modest flights by Monday, with some locally heavy flights in the Upper Midwest likely. The progression of this system will be slow, largely as a function of the slow-moving remnant of Hurricane Harvey to the south; but by late in the period, this low pressure center will pass and usher in widespread moderate to heavy flights. Note that the slow progression of this low pressure across the region will create conditions for shorebird and waterbird fallouts in the Great Lakes, particularly from Monday to Wednesday.

Chestnut-sided Warbler. Wendy Hogan/Macaulay Library. eBird S38549420.

Species on the Move

Beginning Arrivals What is this?

Peaking Arrivals

Beginning Departures

Ending Departures

Gulf Coast and Southeast

A striking duality will be apparent in the region for the period. To the east of the Mississippi River, favorable migration conditions will facilitate moderate to heavy flights for the first half of the period. At the same time, the dangerous and slow moving Hurricane Harvey and its eventual remnants shut down migration to the west of the Mississippi River, particular in coastal Texas and Louisiana. Although most migration in the vicinity of the storm will be grounded, entrained and displaced seabirds, shorebirds, and waterbirds (and perhaps a White-collared Swift or two?) are likely in all coastal areas and on inland bodies of water (but safety is the first priority, always!). To the north of the storm, farther inland, moderate to locally very heavy flights may occur. As this cyclone moves east and loses some strength, slowly, heavy and very heavy flights are likely to the west of precipitation as favorable conditions return. This will be particularly true in Texas by Wednesday and Thursday.

Prothonotary Warbler. Joan Baker/Macaulay Library. eBird S38575686.

Beginning Arrivals What is this?

Peaking Arrivals

Beginning Departures

Ending Departures

Great Plains

A relatively quiet and slow weekend for migration will give way to moderate to heavy flights by Sunday night across the northern and central Plains. Favorable migration conditions will continue for much of the period, but the extent of these conditions will become increasingly restricted by Wednesday and Thursday; so too will the distribution of increasingly less intense flights. By the end of the period, unfavorable conditions for migration are mostly in place, keeping movements local and light. Note, however, that the path of Hurricane Harvey’s remnants may bring a distinctly more tropical flavor to the southern Plains by Thursday or Friday; birders should be safe but watchful, as opportunities to find displaced and entrained seabirds and concentrations of waterbirds and shorebirds are possible.

Buff-breasted Sandpiper. Nick Anich/Macaulay Library. eBird S38797774.

Species on the Move

Beginning Arrivals What is this?

Peaking Arrivals

Beginning Departures

Ending Departures

West

Scattered moderate flights are likely in many areas during this forecast period, particularly over the weekend. Although the extent of flights will be at its greatest on Saturday and Sunday nights, all of the remaining nights of the period will host noticeable movements in many areas. Note that late in the period there is potential for a tropical system to approach the Desert Southwest, a scenario we will watch carefully.

Western Tanager. Marlene Cashen/Macaulay Library. eBird S38438583.

Species on the Move

Beginning Arrivals What is this?

Peaking Arrivals

Beginning Departures

Ending Departures

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