The Ultimate Guide to Migration Online

Drew WeberFeatured, Migration, Science2 Comments

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It’s definitely 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. Originally compiled by Tim Schreckengost several years ago, we will be updating the list going forward as new sources rise and others fall. Also, let us know in the comments if you know of a source we’re missing! Thanks!

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

Below are some great resources to get you started on the path of learning what the radar can tell you about the current or previous night’s migration.

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

Radar Analysis and Predictions – BIRDAR

There are several bird radar enthusiasts out there that post daily analyses and predictions in spring and/or fall. 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.

Continental US – BirdCast Forecasts & Reports
Michigan’s Upper Peninsula – The Northwoods BIRDAR by Max Henschell
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

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.

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 – University of Wisconsin
Real-Time Weather Data – NCAR
Surveillance of the Aerosphere Using Weather Radar (SOAR) – numerous colloborators
Doppler Radar National Mosaic – NOAA’s National Weather Service
Latest US Radar loop – animated loop updated daily


Front Map - Weather Underground

Weather Links

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


More and more, apps are becoming a valuable source of information. Quick access to various radar and weather products, as well as wind conditions and predictions make it easier than ever to plan on the go.

RadarScope – great app for scoping out your local radar
Dark Sky – Hyperlocal Weather, Radar, and Storm Alerts – Dark Sky uses state-of-the-art technology to predict when it will rain or snow — down to the minute — at your exact location
Weather Underground: Forecasts, Interactive Radar, and Weather Alerts – Weather Underground, LLC
Windfinder Pro – Windfinder

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.