Watch for favorable migration conditions progressing eastward this week, affecting the Great Plains Monday and Tuesday and the Midwest and possibly East Coast on Wednesday and Thursday. A cold front approaching the West Coast will bring strong winds to the region on Tuesday.
See animated wind maps for the week.
This week’s weather will feature a large high pressure system moving from southern Canada early in the week, and will be off the East Coast by mid-week. This high pressure system will lead to a prolonged period of southerly winds and very mild weather from the southern Plains up through the Great Lakes and the northeast United States from Tuesday to Thursday. A cold front will drop south later in the week through the Great Lakes, Northeast and Middle Atlantic States replacing the southerly winds with a chilly north wind. Warmer southerly winds should prevail across the southeastern U.S. into the end of the week as the front stalls in the Carolinas.
Wind map for Monday, 5 March 2012, at 925 mb. The small arrows indicate wind direction and the number of hatches indicate wind strength.
Wind map for Wednesday, 7 March 2012, at 925 mb. The green area indicates a nice area of southerly wind flow that should yield significant bird movement through the Great Plains, Midwest, and Great Lakes regions. Along the West Coast a powerful cold front will bring 20-30 mph northwest winds to the region, likely resulting in good from-shore sea-watching conditions.
Species to watch for include: Geese and swans, ducks, Loons, American White Pelican, early herons and egrets, Turkey Vulture, Osprey, Hawks, American Kestrel, Killdeer, American Woodcock, Gulls, Belted Kingfisher, Tree Swallow, Purple Martin (in the south), Brown Creeper, Golden-crowned Kinglet, Hermit Thrush, sparrows (especially Song and Fox) and blackbirds. Early trans-Gulf migrant passerines possibly along the Gulf Coast (e.g., Prothonotary Warbler).
Birders in many areas of the US east of the Rockies should see the signs of new spring arrivals on Tuesday, Wednesday, or Thursday, depending on your location relative to the approach and passage of this high-pressure system. This should include arrivals of early trans-Gulf migrant landbirds in the Gulf of Mexico region. Some light migration may be evident in the central US (primarily east of the Rockies but west of the Great Lakes) by Monday as the system takes shape on its march eastward. By Tuesday, southerly winds and mild weather forecast from the Texas coast to the Great Lakes should produce more widespread and increasingly favorable conditions for diurnal and nocturnal migration.
West Coast sea-watchers could see significant numbers of alcids, gulls, loons, and tubenoses from shore during the blustery conditions following Tuesday’s storm. Be on the lookout for albatrosses as well as Fork-tailed Storm-Petrels during these conditions.
For those examining radar imagery at night, one might expect to see some birds moving (with peak reflectivity values in the 5-15 dBz range, approximating 50-100 birds km-3). For those listening at night, expect to hear the first substantive nocturnal flight calling events of the season (particularly sparrows, Hermit Thrush, Brown Creeper, and waterfowl) as early season migrants continue moving northward. As the system continues to track toward the Atlantic, favorable migration conditions will likely spawn movements in the Ohio River Valley and western Appalachia by Wednesday, perhaps even as far as the Atlantic seaboard. The pattern for this area should continue on Thursday, when many signs of early spring migrants should be apparent. By Friday, the influence of unfavorable conditions after frontal passage will presumably stall migration across much of the eastern US, with the exception of some coastal locations on the Atlantic seaboard.
As always, we encourage you to get out both before and after the weather event, report your birds to eBird, and let us know what you see (email Marshall Iliff with noteworthy observations, and put “eBird BirdCast” as the email subject).
