Horrid autumn- 18/10/17

Dang! It was quiet for viz mig this morning. I was hoping for a fall, but the best was just a late Yellow Wagtail. First four-figure count of Dunlin for the autumn some consolation, though Grey Plover numbers had dropping dramatically.

Which brings me to BirdTAM. It had let me down. No, it hadn't, I had let me down, I fell for the very thing I lecture on about it. I love BirdTAM, but when I explain it to others they hope it is forecasting fallout. It isn't. It's forecasting migration.

Air forces like to be prepared, so their computers are busy predicting when the movements are going to happen, and they do a pretty good job. The southern North Sea is covered by the Belgian air force, who are very happy to share their information with all their chums. The forecast is thinking about movements through airspace. Even though they can, their planes don't skim over the water, they don't need to drop down to see land to readjust for wind drift, they don't all take off when tail winds finally arrive, and they don't only come to land when the drizzle stops.

BirdTAM does not forecast fallout. For that, you still have to play with Met Office info and seek the fronts. Repeat after me:

"All fallout is migration.

Not all migration is fallout."

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There had been a bit of nocturnal arrival, the Dunlin hinted at that. As did the Grey Plovers. And probably there was viz mig, with successful passerine migrants moving that bit too high for me today. The Yellow Wag may well be a winner for my latest date of the year note, but hides the fact it's a loser. Loooo-ser. It should have disappeared weeks ago. Stupid Wagtail. Heading out the gene pool.