Do metal-shafted umbrellas increace the chance of being struck by lightning?
That is, do they function like lightning rods.
I’ve always disliked umbrellas.
Don’t know for sure but …
Anything conductive that tends to intensify the electric field intensity in its vicinity, like a narrow conductive rod or your finger, might very well be a good place to start an electrical discharge.
Here isa site that mentions the effect and both Yahoo! and Google search have many more.