As someone who has the responsibility of calling the runway state, I must admit I am finding this thread both educating and fascinating.
A Wet or Dry runway is an easy call. However, calling a damp runway always ends up with some discussion and some disagreement.
A grooved runway causes problems also. the tops can be dry but the grooves can hold water.
The Atis reflects the runway surface on the last inspection. We do inspect as soon as we can to call a change but obviously there are times when the runway surface changes before we get out there. This is especially the case when the runway dries out quickly.
A pilot who is unsure can always ask for a surface inspection prior to take off.
We pass the runway state in thirds of the runway length. So you can have Wet, Wet, Dry or even Wet, Dry, Wet, or any combination. Am I right in assuming a pilot would use Wet settings if any combination contained a third that was wet?
My observations are UK centric obviously, but, I imagine the same applies internationally.
Any comments that assist us to assist you are welcome.
Happy Christmas.
