New York and Philadelphia Bird Migration Forecast: 21-28 September 2012

Andrew Farnsworth The Cornell Lab Sep 20, 2012

Southerly winds will make for pleasant but perhaps uneventful birding through Saturday, but rain arrives by Saturday night. No new major movements of birds will occur in the area until Sunday night. Migrants that arrived in the heavy movement of Wednesday night and Thursday morning will stay mostly where they are until the next frontal passage. By Sunday morning, low pressure moves east of the metropolitan areas, resulting in clearing skies, cooler temperatures, and a winds shift to the Northwest. Hawk movements and other diurnal migrants should be in evidence as favorable conditions build into the morning hours. Heavy migration will occur Sunday night, and once again, those in quieter areas should listen for flight calls of vocal, passing migrants. In particular, pay attention to increasing numbers of Swainson’s and Gray-cheeked Thrushes, White-throated, Chipping, and Savannah Sparrows, and continuing passage of warblers. Earlier risers on Monday will likely see continuing movements of these nocturnal fliers, so birders in the five boroughs, along the South Shore of Long Island, in coastal NJ, and in inland areas with major topographic features like ridge lines and river valleys should keep an eye skyward. High pressure builds into the region later on Monday, and the following 36-48 hours will see diminishing returns as far as those listening at night and watching hotspots during the day – migration will be light to moderate on Monday and Tuesday night in light southerly winds. Wednesday night and Thursday morning could be interesting – as rain passes ahead of the next approaching high pressure system, winds may shift northerly and northwesterly before skies clear; if this happens, fallouts may be apparent in urban areas, especially those with green space. Birders in New York and Philadelphia should watch this frontal passage closely, to see how the forecast and reality compare, as many birds may be audible during nocturnal movements in low visibility, and large numbers of birds may be visible in migrant traps across the region.