Summer hail storms in Mexico are not unusual. Here is one from 2013: https://www.youtube.com/watch?v=B_YG8Eo5Qho
The hail comes with rain and so the run-off is ice filled and accumulates where it is restricted. This is piss-poor journalism all around.
This one was in Russia....
https://www.youtube.com/watch?v=XodGK_EJV_4