Weather and Migrations
The radar and wind maps together tell the story about this week's Ruby-throat migration. Notice how behind (left) the cold front the winds are coming out of the north. On the radar map the blue circles to the east of the front are birds taking off on migration. These weather tools help us understand the bigger migration picture.

Winds and Nexrad (radar) on Wednesday, April 5, 2017   Courtesy of windyty.com and Paul Hurtado