Matt Whiting wrote:

Yes, ice will form first on small radius surfaces, but not until at or
below freezing temperatures. If you still have water on your wings or
tail, then you won't have ice on your OAT probe.

From what I've observed so far, there's a zone of ambiguity between
about 1 degC and -5 degC where supercooled droplets may or may not
stick to the airframe as ice. I've seen ice form on the tip of my OAT
probe while there were still drops of water running down its sides, as
well as over the rest of the airframe. Freezing is not an
all-or-nothing proposition.


All the best,


David