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Scattered light to moderate flights of Vaux’s Swift, Pacific-slope Flycatcher, Western Tanager, Black-throated Gray Warbler, and Orange-crowned Warbler took flight in the West this week, while moderate flights of Red-eyed Vireo, Warbling Vireo, Swainson’s Thrush, Veery, Gray Catbird, Magnolia Warbler, and Scarlet Tanager became increasingly widespread by the end of the week in the East.

Generally unfavorable migration conditions prevail in the West this week, with those pulses of movements that occur featuring Green Heron, Least Sandpiper, Short-billed Dowitcher, Pacific-slope Flycatcher, Common Yellowthroat, and Clay-colored Sparrow, while the East sees a return to more summer like conditions until more favorable conditions and associated moderate flights of Common Nighthawk, Ruby-throated Hummingbird, Red-eyed Vireo, Blue-winged Warbler, Blackburnian Warbler, and Chipping Sparrow come after the middle of the week.

Moderate and some locally heavy migration was heavily featured across the continent during the past week, with the West seeing pulses of Northern Shoveler, Northern Pintail, Green-winged Teal, Solitary Sandpiper, Pectoral Sandpiper, and Orange-crowned Warbler among other migrants and the East seeing movements including Piping Plover, Solitary Sandpiper, Caspian Tern, Chestnut-sided Warbler, Magnolia Warbler, and Baltimore Oriole.

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Favorable conditions early in the period will bring moderate movements featuring Northern Pintail, Warbling Vireo, Swainson’s Thrush, Wilson’s Warbler, and Western Tanager in parts of the West, particularly the Pacific Northwest, while a passing cold front early in the week will bring moderate to locally heavy movements of Warbling Vireo, Red-eyed Vireo, Veery, Blue-gray Gnatcatcher, Ovenbird, Northern Waterthrush, Blackburnian Warbler, Chestnut-sided Warbler, and Rose-breasted Grosbeak in its wake before southerly flow slows down the system in the East.

Scattered light to moderate movements featuring American Wigeon, Sanderling, Yellow Warbler, Wilson’s Warbler, and Yellow-headed Blackbird highlighted the week in the West, while Black-bellied Plover, Wilson’s Phalarope, Common Nighthawk, Least Flycatcher, Chestnut-sided Warbler, Yellow Warbler, and Wilson’s Warbler composed generally light early period and increasing moderate and even isolated heavy later period movements in the East.

A brief pulse of light to moderate flights that will include American Avocet, Marbled Godwit, Western Sandpiper, Western Kingbird, Barn Swallow, Black-headed Grosbeak, and Bullock’s Oriole on either end of the forecast period highlight otherwise unfavorable conditions across the West, while a relatively weak front drifts east mid week bringing light to moderate flights of Osprey, Greater Yellowlegs, Semipalmated Sandpiper, Ruby-throated Hummingbird, Purple Martin, and Tree Swallow first to the northern Plains, then the Great Lakes, and finally the Appalachians and portions of the eastern seaboard.

All but the latest of migrants already passed, this week saw in the primarily scattered light and highly localized moderate movements across the West, with late migrants featuring Olive-sided Flycatcher, Willow Flycatcher, Cedar Waxwing, and Townsend’s Warbler, while the East saw its light to moderate flights concentrated in the center of the country and featuring primarily departures of Least Sandpiper, White-rumped Sandpiper, Short-billed Dowitcher, Cedar Waxwing, Swainson’s Thrush, Tennessee Warbler, Blackpoll Warbler.

As the spring migration winds down for most species, this forecast period sees early week light to moderate movements in the West that feature Common Nighthawk, White-throated Swift, Warbling Vireo, Cedar Waxwing, and Gray Catbird and mostly moderate flights in the East that feature late season shorebirds, Least Tern, Yell0w-billed Cuckoo, Acadian Flycatcher, Alder Flycatcher, and Cedar Waxwing among other late season passerine migrants.

This period brought light to moderate flights that featured Western Sandpiper, Dunlin, Long-billed Dowitcher, Swainson’s Thrush, and Cedar Waxwing to the West, primarily in the middle of the week and scattered from California to the Rockies and north to Canada, while the East enjoyed moderate to locally heavy early and later week flights that featured Black Skimmer, Common Nighthawk, Black-billed Cuckoo, Yellow-billed Cuckoo, Swainson’s Thrush, Cedar Waxwing, and Dickcissel.

With peaks of spring movements in the rear view for most species, this week will see scattered light flights across much of the West, with moderate flights along the eastern front of the Rockies, that will feature Black Tern, Cordilleran Flycatcher, Willow Flycatcher, MacGillivray’s Warbler, and Blue Grosbeak, and moderate to heavy midweek flights where and when precipitation does not fall in the East, featuring Black-bellied Plover, Black Tern, Olive-sided Flycatcher, Alder Flycatcher, Yellow-bellied Flycatcher, and Mourning Warbler.

A reasonable quiet late migration season week in the West featured movements of Black Tern, Olive-sided Flycatcher, Swainson’s Thrush, Gray Catbird, Northern Waterthrush, American Redstart, particularly in the Desert Southwest and northern Rockies, while moderate to heavy flights in the East early in the week, featuring White-rumped Sandpiper, Sanderling, Black Skimmer, Eastern Wood-Pewee, Marsh Wren, Saltmarsh Sparrow, and Orchard Oriole, subsided as a more early spring like air mass arrived.