WordPress does not recognize update

Greetings all, I am developing a WordPress site on my local machine. It is version 3.13, and I’m trying to update. However, the WordPress update announcement is not showing. Furthermore, when I manually “check for new updates”, it says I’m running the latest version – even though I certainly am not. I haven’t been running the latest version for over a week now, so it’s not a matter of waiting until the update shows.

The updates to my plugins are showing correctly, so it’s also not a matter of connectivity to the update server. Also, the updates to the very same site on the live server ARE showing. Is there any way to force a WordPress upgrade by changing a setting in the options table?

I know I can manually update, but I have a heck of a lot of local sites, I need to find out why this isn’t working.

Thanks!