Popocateptetl sent a big burst of steam, gas and ashes out today. It is reported to have been two kilometers in height. You can read about it in this article which also offers a good explanation of what is happening as well as having a good video of the event. Unfortunately, we weren't on the bus to see it, and even if we had been, we'd have had to time the ride carefully to see it. The article refers you to CENAPRED, Mexico's Center for Protection from Disasters which has even more information and still pictures. I didn't realize it before, but there are actually links for info on the volcano on the site in English. This page is in English. You should explore the site even where it's in Spanish because there's enough illustrative material to interest you even if you don't speak Spanish.
As the article explains, these explosions release pressure and are not (necessarily) signs of an imminent vast explosion. The alert status at Popo remains yellow, level 2.