National Overview
I almost think it’s easier to describe where migration didn’t occur last night, rather than where it did. North winds and heavy precipitation associated with a strong low pressure system over the Northeast appears to have stifled any migration into that part of the country, but otherwise birds were going gangbusters! Migration was hot and heavy up the Central, Mississippi and Eastern Flyways with the most northern reach occurring along the most westerly routes. A frontal boundary across the western Great Lakes appears to have marked to eastern boundary of heavy migration, effectively cutting Wisconsin in half with regards to migration density (see below). Meanwhile conditions over the Gulf of Mexico favored trans-Gulf migration last night so we should expect an influx of new birds along the Gulf Coast today. Southerly flow over the Gulf through midweek also means more neotropical migrants making landfall at last through Thursday morning. April is here; put on your big-boy-birding-pants and do some neck stretches.
Below are the radar loops from sunset last night through 5:00am this morning
New Jersey (Mid Atlantic)
Frames are every 1/2 hour. Click on the thumbnail to view the full-sized animation.
As I said above, the Northeast and most of the Mid Atlantic got skunked for migrants last night. Strong low pressure offshore is bringing both northwest winds and copious precipitation to the region and until it spins off to the northeast I don’t anticipate conditions improving. Small movements of migrants into and out of the region will likely occur “under the radar”, but no large influxes are expected. Hit the breeding locations to dig out early arrivals, or head for the coast to see what interesting concentrations of waterfowl and pelagics may be milling about… and keep an eye on the inland fields and ponds for wayward shorebirds and waterfowl that might have gotten turned around in this system.
Wisconsin (Upper Midwest)
Frames are every 1/2 hour. Click on the thumbnail to view the full-sized animation.
The Upper Midwest as a whole experienced some pretty heavy migration last night with the south and west portions getting the bulk of the birds this morning. You can see on the Green Bay radar above that the frontal boundary running NW->SE across the scene has cut the migration event considerably for most of the eastern portion of the state. There was a pulse of migrants evident last night, with birds heading ESE->WNW away from the lake and the Door Peninsula, but nothing compared to what was going on over La Crosse. Moving over to La Crosse you can see a heavy migration event kicking off just after sunset and continuing into the morning hours. In contrast to Green Bay, the bulk of this event was headed SSE->NNW. Expect a continued increase in spring migrant sightings today with Eastern Towhees, Savannah, Chipping and Swamp Sparrows, and Ruby-crowned Kinglets all becoming more common. Several Louisiana Waterthrush have been found in the state over the last few days so expect more of them to move into their breeding haunts on this migration event. Pine and Yellow-throated Warblers should also become more evident in the next day or two. The dawn chorus is cranking outside my window; nothing new of note, but deafening nonetheless!
Good Birding,
David