none, zilch, nunca. Winds were out of the southwest. No birdies in the sky. Actually, that’s not entirely true. There were lots of birds moving down the central flyway, behind a cold front that is moving our way. Stay tuned tonight!
none, zilch, nunca. Winds were out of the southwest. No birdies in the sky. Actually, that’s not entirely true. There were lots of birds moving down the central flyway, behind a cold front that is moving our way. Stay tuned tonight!
3 responses to “No Migration Detected”
ok, I thought I was getting the hang of this but last night left me confused. The radar looked promising, high db values near the radar with lowering values moving out concentrically. I thought the velocity plot looked appropriate, i.e. speeds about 10 knots greater than wind speed, but there appeared to be North to South and South to North components. Are you basing your determination that there was no migration last night primarily on wind direction? And since there was no migraion, what was causing the readings, temperature inversion?
I’m basing it on the fact that most of the movement last night was South to North. Actually, all of it was South to North after about 10pm (so there might have been a little liftoff of a few birds just after sunset, but they probably stopped as soon as the wind picked up. Temperature inversion wouldn’t have any velocity associated with it, so there must have been some wind-borne particulate (or insect) moving across the radar. Don’t be discouraged! There’s definitely a level of “artistic interpretation” to it all. Hopefully this cold front will move east of us enough to get a good push of migrants behind it and, not coincidently, result in a more interpretable radar image.
Cheers!
Thanks for the reply. I’m not discouraged, just confused which isn’t a new thing for me. 🙂
I’ve only just found out about the technique of using radar to track migration so I realize it will take some time to pick up on the “art” of interpreting the data. Your blog has been very helpful in getting me started, so thank you for that. I also found some additional links, like Clemson University Radar Ornithology Lab that I haven’t had a chance to read through yet.
Thanks!