28 April 2020
Will today be a good day to go birding? Will there be new migrating birds in our area? You don’t have to guess the answer. Just check these maps.
Above, Cornell Lab of Ornithology’s BirdCast uses national radar data to show where, when and in what direction the birds are moving in real time. The screenshot, above, from 4:00am this morning shows intense movement (bright yellow-white) in the Central Great Plains and Mississippi Valley. Birds were also migrating over Pittsburgh but not Philadelphia.
Click on the BirdCast link and play the video to see sunset (red bar) sweep across the continent and the birds start to move. Hotspots soon develop on the map, especially in the pre-dawn hours. That’s where you want to be. When sunrise (yellow bar) sweeps across, migration stops for the day.
If you can’t get outdoors today, see the 2-3 day prediction at CSU’s Aeroeco Lab’s Lights Out Alerts. The website combines historical migration counts with the weather forecast to predict three days of bird migration and alert cities to turn off their lights to save the birds.
According to Lights Out Alerts, last night (April 27-28 “Tonight”) almost 350 million birds flew over the U.S. on their way north. Tomorrow morning (April 28-29) we’ll see the same. Then the weather will suppress movement on the night of April 29-30. NOTE: The labels are a little off. “Tonight” always means “Last Night” if you view the website during the day.
Kyle Horton and his colleagues used historical migration patterns and the current weather forecast to produce the maps. Here’s his long view: A map of peak migration, week by week, across the U.S.
It’s almost time folks! We’re nearing peak migration in portions of the contiguous US. Here’s a <coarse> rule of thumb to let you know when your backyard activity should see a prominent uptick. Dates derived from two decades of radar data. #birding #ornithology pic.twitter.com/YWA55981vE— Kyle Horton (@Kyle__Horton) April 21, 2020
Based on these maps I’d say that birding will be good today in Pittsburgh … when the rain stops.
UPDATE September 2020: In late August BirdCast added migration forecast tools to their website. Click here for Forecast Maps, Live migration maps and Local Alerts.