Dave wrote:
Andy Champ wrote:
Dave wrote:

That raises a question. Major roads around here (A6) have been
gritted. But I still find my ABS kicks in on an apparently clear
road. The temperature is only 0 degrees C.

WTF is going on? It can't be black ice. It's not cold enough.


If the sky is clear, and the sun is not on the road, radiative cooling
can get the surface temperature a _long_ way below the air temperature.

R. Thanks for that, I hadn't considered it.

cf ground frost vs air frost.

Dave