https://api.twitter.com/1/statuses/user_timeline.rss?screen_...
https://api.twitter.com/1/statuses/user_timeline.rss?screen_...
If you put http://blog.jquery.com/ into your feedreader it should be able to just automatically detect the feed (it's embedded in the page using a <link rel="alternate" type="application/rss+xml" .../>).
I've seen multiple commenters at the jQuery Blog state that the feed is broken for them too. The following search results bring up some of these comments:
https://google.com/search?q=site:blog.jquery.com+broken+feed...
I recall that this issue was acknowledged at some point by one of the contributors at the jQuery Blog. I don't recall who acknowledged it though, but I seem to recall that they stated it would be fixed eventually, which is why I didn't look for a solution until today.