Quote Originally Posted by PSRB View Post
Is that is in Manchester? I assume TEMPO is temperature, max/min?
It is Manchester, yes. TEMPO is a temporary condition occurring between two stated times, so in the example above:

PROB30 TEMPO 2521/2606 8000 BKN008 means a 30% probability that temporarily between 21:00 GMT on the 25th and 06:00 GMT on the 26th, the visibility will be 8000 metres and there will 6/8 cloud at 800'.

There. I've revealed all the secret code.