Popocatépetl is already erupting, in the sense that it has been showing regular volcanic activity since 1994. However, its current eruptions are generally low to moderate magnitude.
The more important question is: Will it have a large and destructive eruption? The answer is: Possibly, but short-term probability is relatively low.
Popocatépetl has experienced periods of intermittent increased activity in the last 30 years, with explosive eruptions ejecting ash, gases, and volcanic rock several kilometers high. These eruptions can cause significant impact in surrounding areas, especially in terms of air quality and visibility.
A catastrophic eruption similar to one that occurred thousands of years ago is possible but less likely in the next century. Continuous monitoring by UNAM's Institute of Geophysics and CENAPRED keeps authorities alert to changes that could indicate escalating activity.
For nearby residents: keep N95 masks at home, monitor official CENAPRED alerts, and have an evacuation plan if alert levels increase.