New York City/Philadelphia Metropolitan Migration Forecast – 14-21 September 2012

Continued warm, southerly winds do not bring many new birds to the region on Friday and Saturday. However, a passing cold front brings a wind shift on Saturday, and as northwesterly winds blow through the night and into early Monday morning, migrants will respond. Heavy migration will occur Saturday night, with some continued flight of birds on Sunday morning along the immediate coast around New York. Saturday night, in particular, would be a good night to listen to a lively nocturnal flight call chorus of migrant thrushes, grosbeaks, and warblers. Birders in both metropolitan areas should watch city parks on Sunday and Monday mornings for larger numbers of songbirds, including one of the last big pulses of migrant warbler diversity. Additionally, larger songbirds like Scarlet Tanager, Swainson’s Thrush, and Rose-breasted Grosbeak should be apparent. Numbers of Northern Flickers will begin to increase, and movements of this species may be apparent on Sunday and Monday mornings. Sky watchers should see numbers of hawks migrating, in particular Broad-winged Hawk. Manhattan should once again see a flight of this species, in addition to Ospreys, American Kestrel, Sharp-shinned Hawk, and the occasional Bald Eagle. After this early pulse of birds, conditions deteriorate for migration through Wednesday. Low pressure to the north will bring rain and stronger southerly winds, all but shutting down migration. After the system passes on Wednesday, perhaps with a late day hawk movement depending on how quickly winds shift northwesterly, conditions improve slightly for migration. However, because the high pressure associated with this frontal passage is to our south, both metropolitan areas will not see the flood gates open as skies clear.  Rather, migration amounts will be moderate in marginal, southerly winds.