As a Tower controller I hope I have an idea of when wx avoiding might be required, but I rely on the pilots telling me what they require and when as we have no idea of where the cells are.
It creates a lot of extra workload for the Tower as well (granted not as much as radar) but when every hold is blocked with all aircraft refusing to take-off due to a cell on climb-out, and they’re still landing, carnage ensues. So let us know nice and early what your requirements are and we’ll do our best to get you airborne asap.