8-15 May 2015 Regional Migration Forecast: Peaks and valleys
Continental Summary
Favorable conditions for light to moderate flights begin and ends the period for the West as Black-bellied Plover, Lesser Yellowlegs, Willow Flycatcher, Swainson’s Thrush, Townsend’s Warbler, Virginia Warbler, and Blue Grosbeak are on the move, while the moderate to heavy flights that will include White-rumped Sandpiper, Short-billed Dowitcher, Least Flycatcher, Philadelphia Vireo, Blackpoll Warbler, Chestnut-sided Warbler, Wilson’s Warbler, Rose-breasted Grosbeak, Savannah Sparrow and White-crowned Sparrow navigate around some serious weather in the first half of the period and quiet markedly with that weather’s departure to end the period.
[animation name=”8-15-may-2015-forecast”]
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.
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Quick Links to Regions
Upper Midwest and Northeast![]() |
Gulf Coast and Southeast![]() |
Great Plains![]() |
West![]() |
Upper Midwest and Northeast
A swath of favorable conditions spans the region from the Mississippi River valley east and north through the Appalachians into New England at time during the first half of the period, though peppered and doused, at times, with precipitation. Where and when rain is not falling, moderate to heavy flights will occur as migration peaks in the region, including some very heavy flights. But these movements will not be widespread given the forecast for storms. By Tuesday night and Wednesday the atmospheric disturbances generating the storms begin to depart, as does the influence of the spinning subtropical storm in the Atlantic, ushering in a cooler blast of unfavorable conditions that will put the brakes on these larger movements of birds for the latter portion of the forecast period. Note, the effects of subtropical storm Ana will most certainly shut down movements in the coastal mid Atlantic during the early to middle parts of the period, but birders should watch carefully, particularly in coastal locations for storm-driven waifs (although most of this action, if there is any, will be farther south) that include tropical pelagic species and concentrations of inbound Neotropical migrants.
Species on the Move
[expand title=”Beginning to Arrive %(%span style=’font-size: 10px; vertical-align: super;’%)%%(%a href=’https://birdcast.org/news/definitions-species-arrivals-regions-and-migration-amounts/#definitions’ target=’_blank’%)%What is this?%(%/a%)%%(%/span%)%” tag=”h3″]
[table sort=”,asc” tablesorter=”true”]
Species,Begin Arrival[attr style=”color:green”],Rapid Influx,Peak,Rapid Depart
Yellow-bellied Flycatcher,5/8,5/15,5/25,6/4
Willow Flycatcher,5/8,5/17,6/1,-
Alder Flycatcher,5/11,5/19,5/31,6/11
[/table]
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[expand title=”Arriving” tag=”h3″]
[table sort=”,,asc” tablesorter=”true”]
Species,Begin Arrival,Rapid Influx[attr style=”color:green”],Peak,Rapid Depart
Philadelphia Vireo,5/1,5/8,5/18,5/28
Wilson’s Warbler,5/1,5/8,5/18,5/28
Short-billed Dowitcher,4/30,5/8,5/18,5/29
Common Tern,4/28,5/8,-,-
Blackpoll Warbler,5/1,5/9,5/18,5/29
Black Tern,4/30,5/9,5/22,-
Red-eyed Vireo,4/27,5/9,5/26,-
Canada Warbler,5/3,5/10,5/19,5/29
Semipalmated Plover,5/2,5/10,5/20,6/1
Yellow-billed Cuckoo,4/27,5/10,5/31,-
Dunlin,5/4,5/11,5/20,5/31
Common Nighthawk,5/3,5/11,5/21,5/31
Black-billed Cuckoo,5/1,5/11,5/25,6/4
Olive-sided Flycatcher,5/5,5/12,5/22,6/1
Black-bellied Plover,5/5,5/12,5/22,6/2
Black Skimmer,5/3,5/12,-,-
Least Tern,5/3,5/12,-,-
Mourning Warbler,5/5,5/13,5/23,6/1
Ruddy Turnstone,5/6,5/13,5/23,6/2
Sanderling,5/6,5/13,5/22,6/3
Semipalmated Sandpiper,5/5,5/13,5/24,6/4
Eastern Wood-Pewee,5/4,5/13,5/28,-
Yellow-bellied Flycatcher,5/8,5/15,5/25,6/4
White-rumped Sandpiper,5/6,5/15,5/26,6/7
[/table]
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[expand title=”Peaking” tag=”h3″]
[table sort=”,,,asc” tablesorter=”true”]
Species,Begin Arrival,Rapid Influx,Peak[attr style=”color:green”],Rapid Depart
Orange-crowned Warbler,4/21,4/29,5/8,5/19
White-crowned Sparrow,4/23,4/29,5/8,5/19
Prothonotary Warbler,4/9,4/21,5/8,5/22
Red-winged Blackbird,-,3/10,5/8,-
Summer Tanager,4/19,4/27,5/9,5/17
Black-and-white Warbler,4/21,4/29,5/9,5/19
Nashville Warbler,4/23,4/30,5/9,5/19
Red-headed Woodpecker,4/19,4/28,5/9,-
Blue-winged Warbler,4/20,4/28,5/10,5/18
Black-throated Green Warbler,4/22,4/30,5/10,5/20
Northern Waterthrush,4/22,4/30,5/10,5/21
Northern Parula,4/22,4/30,5/10,5/21
Forster’s Tern,3/28,4/29,5/10,5/24
Tree Swallow,3/21,4/3,5/10,-
Kentucky Warbler,4/18,4/27,5/10,-
Hooded Warbler,4/18,4/27,5/10,-
Black-throated Blue Warbler,4/25,5/1,5/11,5/21
Lincoln’s Sparrow,4/24,5/1,5/11,5/22
Green Heron,4/14,4/25,5/11,-
Rose-breasted Grosbeak,4/23,5/1,5/12,5/21
Golden-winged Warbler,4/25,5/2,5/12,5/22
Cape May Warbler,4/26,5/2,5/12,5/22
House Wren,4/18,4/27,5/12,-
Cerulean Warbler,4/19,4/28,5/12,-
Yellow-throated Vireo,4/21,4/30,5/13,-
Orchard Oriole,4/21,4/30,5/13,-
Wood Thrush,4/22,5/1,5/13,-
Ovenbird,4/23,5/1,5/13,-
Spotted Sandpiper,4/17,4/30,5/14,5/27
Great Blue Heron,3/11,3/21,5/14,-
Yellow Warbler,4/22,5/1,5/14,-
Baltimore Oriole,4/24,5/2,5/15,5/24
Blackburnian Warbler,4/26,5/4,5/15,5/25
Tennessee Warbler,4/27,5/5,5/15,5/26
Swainson’s Thrush,4/27,5/5,5/15,5/26
Gray-cheeked Thrush,4/28,5/5,5/15,5/26
Bay-breasted Warbler,4/28,5/6,5/15,5/26
Least Sandpiper,4/26,5/4,5/15,5/27
Common Grackle,-,3/2,5/15,-
Great Egret,3/20,4/1,5/15,-
Warbling Vireo,4/22,5/1,5/15,-
Gray Catbird,4/23,5/2,5/15,-
[/table]
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[expand title=”Departing” tag=”h3″]
[table sort=”,,,,asc” tablesorter=”true”]
Species,Begin Arrival,Rapid Influx,Peak,Rapid Depart[attr style=”color:green”]
Ruby-crowned Kinglet,4/2,4/12,4/25,5/8
Sharp-shinned Hawk,3/24,4/10,4/22,5/9
White-throated Sparrow,4/9,4/18,4/28,5/11
Cooper’s Hawk,3/16,4/9,4/24,5/13
Swamp Sparrow,3/31,4/13,4/29,5/14
Louisiana Waterthrush,3/26,4/5,4/30,5/14
[/table]
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Gulf Coast and Southeast
Moderate to heavy flights will be widespread in the western portions of the region for the first half of the week, while the effects of subtropical storm Ana will shut down movements in more eastern areas until it departs. Birders in southeastern coastal plain should watch for potential effects of this storm in the arrivals both of pelagic species inshore and downed inbound Neotropical migrants. Additionally, birders should watch the distribution of precipitation carefully, as localized concentrations of inbound migrants may occur after their flights over the Gulf of Mexico and Caribbean Sea may encounter scattered precipitation. The latter half of the period brings a substantial change to the region, with a frontal boundary once again approaching and entering the Gulf of Mexico, creating late season fallout potential, and with the departure of low pressure and the subtropical storm ushering in much less favorable migration conditions of scattered light to moderate movements.
[expand title=”Beginning to Arrive %(%span style=’font-size: 10px; vertical-align: super;’%)%%(%a href=’https://birdcast.org/news/definitions-species-arrivals-regions-and-migration-amounts/#definitions’ target=’_blank’%)%What is this?%(%/a%)%%(%/span%)%” tag=”h3″]
No more for this year – but still plenty peaking!
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[expand title=”Arriving” tag=”h3″]
No more for this year – but still plenty peaking!
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[expand title=”Peaking” tag=”h3″]
[table sort=”,,,asc” tablesorter=”true”]
Species,Begin Arrival,Rapid Influx,Peak[attr style=”color:green”],Rapid Depart
Least Flycatcher,4/21,4/29,5/9,5/20
Wilson’s Warbler,4/22,4/30,5/9,5/20
Eastern Wood-Pewee,4/13,4/26,5/10,5/22
Scissor-tailed Flycatcher,3/15,3/26,5/10,-
Cliff Swallow,3/15,4/1,5/10,-
Canada Warbler,4/23,5/1,5/11,5/22
Chimney Swift,3/23,4/3,5/11,-
Mourning Warbler,4/24,5/1,5/12,5/23
Olive-sided Flycatcher,4/22,5/1,5/12,5/24
Western Kingbird,4/7,4/17,5/12,-
Semipalmated Sandpiper,3/28,4/14,5/13,5/29
White-rumped Sandpiper,4/22,5/1,5/14,5/27
Willow Flycatcher,4/26,5/4,5/15,5/26
Yellow-bellied Flycatcher,4/27,5/5,5/15,5/26
Black Tern,4/3,4/14,5/15,-
[/table]
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[expand title=”Departing” tag=”h3″]
[table sort=”,,,,asc” tablesorter=”true”]
Species,Begin Arrival,Rapid Influx,Peak,Rapid Depart[attr style=”color:green”]
Rose-breasted Grosbeak,4/10,4/17,4/27,5/8
Savannah Sparrow,-,-,-,5/8
Nashville Warbler,4/4,4/15,4/26,5/9
Black-and-white Warbler,3/10,4/17,4/26,5/9
Yellow-headed Blackbird,4/7,4/15,4/27,5/9
Baltimore Oriole,4/9,4/17,4/28,5/9
Cape May Warbler,4/10,4/17,4/28,5/9
Lesser Yellowlegs,3/11,4/15,4/24,5/10
Gray Catbird,4/9,4/17,4/27,5/10
Ovenbird,4/8,4/17,4/29,5/10
Golden-winged Warbler,4/11,4/18,4/29,5/10
Northern Parula,-,3/2,4/17,5/11
Solitary Sandpiper,4/1,4/15,4/27,5/11
Orchard Oriole,3/30,4/10,4/28,5/11
Tennessee Warbler,4/5,4/15,4/28,5/11
Northern Waterthrush,4/9,4/17,4/28,5/11
Black-throated Blue Warbler,4/11,4/19,4/30,5/11
Black-throated Green Warbler,4/7,4/17,4/29,5/12
Clay-colored Sparrow,3/25,4/19,4/29,5/12
Gray-cheeked Thrush,4/11,4/19,4/30,5/12
Veery,4/12,4/19,5/1,5/12
Pine Siskin,-,-,-,5/13
Ruby-throated Hummingbird,3/16,4/4,4/28,5/14
Blackpoll Warbler,4/12,4/20,5/2,5/14
Blue-headed Vireo,-,-,4/8,5/15
Western Sandpiper,-,-,4/13,5/15
Bobolink,4/15,4/23,5/4,5/15
Bay-breasted Warbler,4/17,4/25,5/5,5/15
[/table]
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Great Plains
A slowly building and slow moving low pressure system advancing through the region brings a mix of cooler and unfavorable conditions to the northern Plains and favorable warm conditions to the southern Plains to start the weekend as the disturbance passes. The associated moderate to heavy flights in the southern Plains will gradually lose ground to the light to moderate flights of the northern Plains as the unfavorable conditions spread across the region by Sunday and Monday. The effects of this system’s passage will continue through most of the week, so birders should expect light to locally moderate flights during this period. Note that some areas where winds are calmer will experience higher intensity movements, given the time of year and the need for birds to arrive on breeding territories. Thursday night will see a return of moderate to very heavy flights that are widespread across the region.
Species on the Move
[expand title=”Beginning to Arrive %(%span style=’font-size: 10px; vertical-align: super;’%)%%(%a href=’https://birdcast.org/news/definitions-species-arrivals-regions-and-migration-amounts/#definitions’ target=’_blank’%)%What is this?%(%/a%)%%(%/span%)%” tag=”h3″]
[table sort=”,asc” tablesorter=”true”]
Species,Begin Arrival[attr style=”color:green”],Rapid Influx,Peak,Rapid Depart
Western Wood-Pewee,5/15,5/24,6/6,-
[/table]
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[expand title=”Arriving” tag=”h3″]
[table sort=”,,asc” tablesorter=”true”]
Species,Begin Arrival,Rapid Influx[attr style=”color:green”],Peak,Rapid Depart
Chestnut-sided Warbler,4/30,5/8,5/17,5/28
American Redstart,5/1,5/8,5/18,5/28
White-rumped Sandpiper,4/30,5/8,5/19,5/30
Veery,4/30,5/8,5/18,-
Bobolink,4/30,5/8,6/16,-
Blackburnian Warbler,5/1,5/9,5/18,5/28
Magnolia Warbler,5/1,5/9,5/18,5/28
Lark Bunting,4/27,5/9,5/31,-
Dunlin,4/12,5/10,5/18,5/29
Cape May Warbler,5/3,5/10,5/19,5/29
Olive-sided Flycatcher,5/3,5/10,5/20,5/31
Acadian Flycatcher,4/29,5/10,5/22,6/2
Black Tern,5/2,5/10,5/21,-
Yellow-breasted Chat,4/25,5/10,6/3,-
Ruddy Turnstone,5/4,5/11,5/20,5/30
Mourning Warbler,5/4,5/11,5/20,5/30
Red-necked Phalarope,5/4,5/11,5/21,5/31
Canada Warbler,5/5,5/12,5/21,5/30
Alder Flycatcher,5/6,5/13,5/22,6/1
Black-capped Vireo,4/23,5/13,6/4,-
Willow Flycatcher,5/4,5/13,6/12,-
Yellow-bellied Flycatcher,5/7,5/14,5/23,6/2
Least Tern,5/4,5/14,5/30,-
Yellow-billed Cuckoo,4/30,5/14,6/5,-
Common Nighthawk,5/1,5/15,6/2,-
Dickcissel,4/23,5/15,-,-
[/table]
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[expand title=”Peaking” tag=”h3″]
[table sort=”,,,asc” tablesorter=”true”]
Species,Begin Arrival,Rapid Influx,Peak[attr style=”color:green”],Rapid Depart
Palm Warbler,4/20,4/28,5/8,5/18
Purple Martin,3/19,4/7,5/8,-
Nashville Warbler,4/22,4/29,5/9,5/19
Clay-colored Sparrow,4/22,4/29,5/9,5/19
Blue-headed Vireo,4/23,4/30,5/9,5/19
Least Sandpiper,4/17,4/28,5/9,5/23
Eastern Towhee,3/22,4/28,5/9,-
Black-and-white Warbler,4/23,4/30,5/10,5/20
Northern Waterthrush,4/24,5/1,5/11,5/22
Spotted Sandpiper,4/17,4/28,5/11,5/24
Brown-headed Cowbird,3/17,4/22,5/11,-
Summer Tanager,4/19,4/28,5/11,-
Golden-winged Warbler,4/26,5/2,5/12,5/22
Black-throated Green Warbler,4/23,5/1,5/12,5/23
Pectoral Sandpiper,3/13,3/25,5/12,5/28
Semipalmated Sandpiper,4/8,4/17,5/12,5/29
House Wren,4/15,4/26,5/12,-
Wood Thrush,4/24,5/2,5/13,5/24
Swainson’s Thrush,4/24,5/2,5/13,5/24
Rose-breasted Grosbeak,4/25,5/2,5/13,5/24
Gray-cheeked Thrush,4/26,5/3,5/13,5/24
Green Heron,4/11,4/23,5/13,-
Kentucky Warbler,4/20,4/30,5/13,-
Indigo Bunting,4/22,4/30,5/13,-
Yellow-throated Vireo,4/22,5/1,5/13,-
Baltimore Oriole,4/22,5/1,5/14,5/24
Least Flycatcher,4/26,5/3,5/14,5/25
Wilson’s Warbler,4/27,5/4,5/14,5/26
Warbling Vireo,4/20,4/30,5/14,-
Blackpoll Warbler,4/28,5/5,5/15,5/26
Tennessee Warbler,4/27,5/5,5/15,5/27
Chimney Swift,4/15,4/27,5/15,-
Great Crested Flycatcher,4/20,4/30,5/15,-
Bank Swallow,4/12,5/1,5/15,-
[/table]
[/expand]
[expand title=”Departing” tag=”h3″]
[table sort=”,,,,asc” tablesorter=”true”]
Species,Begin Arrival,Rapid Influx,Peak,Rapid Depart[attr style=”color:green”]
Savannah Sparrow,3/18,4/15,4/25,5/8
Ruddy Duck,-,3/18,4/5,5/10
Hermit Thrush,3/23,4/5,4/23,5/10
Lesser Yellowlegs,4/2,4/14,4/26,5/10
Blue-winged Teal,3/11,3/23,4/21,5/12
White-throated Sparrow,4/11,4/21,5/1,5/14
Harris’s Sparrow,-,4/23,5/1,5/14
Solitary Sandpiper,4/14,4/23,5/3,5/14
Ruby-crowned Kinglet,3/23,3/31,5/1,5/15
Broad-winged Hawk,4/5,4/16,5/1,5/15
Long-billed Dowitcher,4/12,4/20,5/1,5/15
White-crowned Sparrow,4/18,4/25,5/4,5/15
[/table]
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West
A quiet start is on tap for the region, as scattered light movements will occur in largely marginal and unfavorable conditions for the weekend. By Monday night, moderate movements return with more favorable conditions, particularly in the Desert Southwest and intermontane regions. As these conditions become increasingly widespread for the remainder of the period, so to will moderate movements become more widespread. Some of these movements in the northern Rockies and grasslands of Montana may be heavy.
Species on the Move
[expand title=”Beginning to Arrive %(%span style=’font-size: 10px; vertical-align: super;’%)%%(%a href=’https://birdcast.org/news/definitions-species-arrivals-regions-and-migration-amounts/#definitions’ target=’_blank’%)%What is this?%(%/a%)%%(%/span%)%” tag=”h3″]
[table sort=”,asc” tablesorter=”true”]
Species,Begin Arrival[attr style=”color:green”],Rapid Influx,Peak,Rapid Depart
Willow Flycatcher,5/12,5/23,6/7,-
Heermann’s Gull,5/15,6/29,-,-
[/table]
[/expand]
[expand title=”Arriving” tag=”h3″]
[table sort=”,,asc” tablesorter=”true”]
Species,Begin Arrival,Rapid Influx[attr style=”color:green”],Peak,Rapid Depart
Swainson’s Thrush,4/27,5/9,-,-
Blue Grosbeak,4/17,5/12,5/26,-
Gray Catbird,5/6,5/15,5/30,-
Cedar Waxwing,5/1,5/15,6/1,-
[/table]
[/expand]
[expand title=”Peaking” tag=”h3″]
[table sort=”,,,asc” tablesorter=”true”]
Species,Begin Arrival,Rapid Influx,Peak[attr style=”color:green”],Rapid Depart
Townsend’s Warbler,4/20,4/28,5/8,5/21
American White Pelican,3/23,4/5,5/8,-
Forster’s Tern,4/12,4/24,5/9,-
Virginia’s Warbler,4/16,4/26,5/9,-
Sora,4/18,4/28,5/10,5/23
Violet-green Swallow,-,3/4,5/10,-
Blue-gray Gnatcatcher,3/20,4/15,5/10,-
Cassin’s Vireo,3/28,4/19,5/10,-
Wilson’s Phalarope,4/18,4/28,5/11,5/22
Wilson’s Warbler,4/11,4/24,5/11,5/27
Tree Swallow,3/2,4/2,5/11,-
Red-necked Phalarope,4/15,4/28,5/12,5/27
Hammond’s Flycatcher,4/6,4/23,5/12,-
Lark Sparrow,4/12,4/25,5/12,-
Green Heron,4/3,4/18,5/13,-
Chipping Sparrow,4/17,4/29,5/13,-
Clay-colored Sparrow,4/27,5/4,5/14,5/25
Spotted Sandpiper,4/21,4/30,5/14,5/26
[/table]
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[expand title=”Departing” tag=”h3″]
[table sort=”,,,,asc” tablesorter=”true”]
Species,Begin Arrival,Rapid Influx,Peak,Rapid Depart[attr style=”color:green”]
Black-bellied Plover,-,-,4/22,5/8
Lesser Yellowlegs,4/4,4/14,4/25,5/9
Dunlin,4/10,4/17,4/26,5/9
Nashville Warbler,4/2,4/13,4/27,5/9
Willet,4/10,4/17,4/27,5/9
Least Sandpiper,4/10,4/17,4/27,5/9
Cooper’s Hawk,-,3/3,3/29,5/10
Western Sandpiper,4/9,4/17,4/28,5/10
Whimbrel,3/18,4/19,4/28,5/10
Eared Grebe,-,4/7,4/21,5/11
Semipalmated Plover,4/11,4/19,4/29,5/11
Solitary Sandpiper,4/12,4/21,5/1,5/13
Orange-crowned Warbler,3/21,4/2,5/1,5/15
Long-billed Dowitcher,4/16,4/24,5/3,5/15
[/table]
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Farnsworth and Van Doren
Scientific Team
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