Hi, can anyone identify how these relatively large spots on my hood (front and center) appeared and how to remove them?

The only event I can remember that may have caused it was using a new car cover.

Regardless, I would like some tips on trying to get rid of it short of wet sanding.

 

Try a mild polish, if not try something harsher.
The problem might be in the paint rather than on the surface.

 

Whatever you do always start with a claybar to clean the clearcoat, which could possibly help with that also.

 

It very likely is a fogging under your clear coat. Seen often when a car cover or one of the old leather like bra covers would get wet, then sit in sun, or even remain wet during very humid weather periods. If that is the case, I've seen the majority of those dissipate on their own. Leave it in sun, without the cover obviously, and a couple of days should get rid of it.

With no success from nature, I agree with the above suggestions; clay & a mild polish.

 

Wash, then use a clay when needed. Polishing can be an optional step but its also a good idea if you want keep your paint looking at it's best.