A strong cold front has moved off the Atlantic coast after a week of more summer-like conditions. Friday night will see temperatures drop in many areas, with winds from the North and Northwest, perfect for moderate to heavy movements in many areas (and some locally very heavy movements). These large movements of birds will be audible in many areas, and Friday night will be an excellent opportunity to experience the spectacle of nocturnal migration acoustically! Those in New York State, portions of northeastern Pennsylvania, the greater Washington DC area, and portions of northern New England may have exceptional opportunities to listen, because of the forecast for extensive and low-level cloud cover. Areas shaded in greens and blues will experience mostly cloudy to totally overcast conditions and low cloud ceilings.
Birders across the region should plan to spend some hours listening this evening, and those of you that have microphones should make sure they are functional and that your recorders are turned on! A strong frontal passage that is followed by extensive moisture aloft, extensive cloud cover, and low cloud ceiling, particularly after days of much warmer conditions, is a recipe for high-calling events. This is particularly true in areas in which artificial illumination is shining beneath the cloud cover. The combination of light and poor visibility is correlated with high call counts, and early mid-September is period of great diversity of passing nocturnal migrants.
