The Ultimate Guide to Migration Online

It’s time for migration and birds are already on the move throughout the country! Where should you look for predictions, background info, or anything else related to migration? What follows is an ever-changing list of readily available migration related resources. We will be updating the list throughout the year as new sources rise and others fall. Also, let us know in the comments if you know of a source we’re missing! Thanks!

National composite banner

Before attempting to interpret biological movements on the NEXRAD, you need to understand how it works and how to tease birds, insects, and bats apart. After reading the material in the following links, you should be well on your way to making an educated analysis and prediction on the previous night’s migration.

Understanding BIRDAR

There are several dedicated nerds out there that post daily analyses and predictions. The folks at the following sites get up early, usually predawn, and make a prediction on what should be seen on the ground that morning. If you’re birding in an area covered by one of the following sites, be sure to post your sightings on their posts.

Interpreting Radar Video from Woodcreeper
Radar & Migration FAQ from Woodcreeper
Tutorial on the NEXRAD and how to read it from Clemson University
NEXRAD Ornithology by Mike McDowell from Eagle Optics
Understanding Radar and Birds from Team eBird & BirdCast
Identification of Bird Migration Events in NEXRAD Data from Northern Rocky Mountain Science Center
How NEXRAD sees the atmosphere from New Jersey Audubon

Radar Analysis and Predictions – BIRDAR

Upper Midwest – Woodcreeper by David La Puma
Michigan’s Upper Peninsula – The Northwoods BIRDAR by Max Henschell
New England – Tom Auer’s blog by Tom Auer
Florida/SE – Badbirdz Reloaded by Angel and Mariel Abreu
NW Ohio – Birding the Crane Creek by Kenn Kaufman
Pacific NW – Birds Over Portland by Greg Haworth
Continental US – eBird BirdCast Forecasts & Reports by Team eBird

You can access current and future radar images at the following links. Each link gives you something different as far as region, the layout, and availability of archived data.

NWS Enhanced Radar Mosaic - Northeast Sector

Radar Links

An integral part of understand migration and radar is understanding the weather. By keeping an eye on storms, fronts, and various pressure systems, you can predict when big movements are going to take place days before they actually occur.

National Composite from the University of Wisconsin
Real-Time Weather Data from NCAR
Surveillance of the Aerosphere Using Weather Radar (SOAR) from numerous colloborators
Doppler Radar National Mosaic from NOAA’s National Weather Service
Paul Hurtado’s NEXRAD Archive


Front Map - Weather Underground


Weather Underground – General, Forecast Map, Current Conditions, Wind Map, Weather Radar
Intellicast – General, Radar, Wind
Forecast – General
NOAA’s National Weather Service – General, Forecast Map, National Doppler Radar
NOAA’s Aviation Weather Center – General
The Weather Channel – General, National Doppler Radar
Interactive Wind Map from HINT.FM
Rutgers Weather Center – General 

Weather Apps

Dark Sky – “Dark Sky uses state-of-the-art technology to predict when it will rain or snow — down to the minute — at your exact location, and presents it to you alongside the most beautiful weather visualizations you’ve ever seen.”


It’s nothing fancy, but we do have a Bird Migration app available in the iTunes App Store that will give you quick access to many of the resources above from your iPhone.

Quick guide to interpreting the radar

Reflectivity radar images show the magnitude of migration. When birds are migrating, it looks like a donut shape around the center of the radar station.

Velocity radar shows the direction that the objects detected by the radar station are moving. Blues are moving towards the radar station, yellows and reds are moving away from the station. So for southbound migration, blue should be on the top half of the donut, yellow on the bottom half.

Watch for precipitation moving through during the night hours, this can cause birds to stop migrating in a concentrated area, creating the fabled ‘fallout’, particularly on nights with strong migration.