You will never see a TS hit an aerodrome that is not forecast in a TAF; fact. It might be forecast only moments before, but it will happen.
NOT TRUE
I'm sorry but I have seen a TS hit SYD that was unforecast. Watched a huge line of CBs out out the window and on Wx radar as we flew into SYD. Nothing on the TAF or TTF. Acft dodging left right and centre as they arrived and departed SYD. Nothing on the TAF or TTF. Safely parked at the terminal when the TS hit. Lighnting strikes, heavy rain, black as midnight at 4 in the afternoon. Airport closed to all activities. Nothing on the TAF or TTF. The first forecast to mention TS was a TTF SPECI issued
seven minutes after the storm hit the airfield.