Despite a reasonably quiet season for tropical systems in the western North Atlantic, a lingering area of low pressure and associated storms that was once Tropical Storm Gabrielle has reorganized and started to move to the North and Northeast. The most current update from the National Hurricane Center suggests a western Newfoundland landfall for the system early on Saturday morning.
The forecast track of this system takes it rather rapidly from the vicinity of Bermuda North near the continental shelf, grazing Nova Scotia, and then finally to Newfoundland. The speed and origin of this system suggest that it could entrain a number of more southerly, warmer water species, and deposit them on the island, particular East of the system’s landfall, beginning early Saturday morning. First and foremost, birders should exercise extreme caution when birding a tropical system of any kind, as dangerous conditions will exist before, during, and after the system’s arrival; but for those that can do so safely, seawatching, skywatching, and lake-watching could prove fruitful for this storm on Saturday and Sunday. This storm has potential to entrain a number of warm water pelagic species including White-tailed Tropicbird and Bridled Tern, perhaps some of the widely wandering Pterodroma reported this season, as well as numbers of more typical New England pelagics. See our previously primer on hurricane birding for more details, as the passage of Hurricane Irene in 2011 will probably shed light on what to expect with this system.
Additionally, as has been the case with numerous tropical systems that go extra-tropical, there is potential for wrap-around landbird fallouts. In such events, birds that depart to the South and West of the passage of a tropical system’s circulation become entrained, eventually falling out at nearest landfall. The imagery below suggests that birds departing the coast of the Northeastern US after the passage of a substantial cold front, flying in strong northwesterly winds, may have the potential to become entrained in the circulation of Gabrielle. The presence of a strong high pressure system circulating in the North Atlantic may facilitate this, with some strong southwesterly flow forecast between the approaching continental air mass and the marine air mass. Birders in Newfoundland should watch for the arrival of wayward songbirds in the days immediately following the passage of the storm. Furthermore, birders across the Atlantic in the UK and the Azores in particular should be watchful for Nearctic vagrants as the system moves East.