Liquid hot magma? Not a good thing, and even less so when the volcano rumbling with indigestion lies just a couple of dozen miles from one of the most populous cities on Earth.

For the past few months, the Popocatepetl volcano southeast of the capital has been spewing chunks of flaming, incandescent rock and burping up clouds of hot white ash and steaming gray vapors.

At night, residents can see the glowing peak of the snowcapped volcano locals call El Popo. It is very dramatic to witness Earth’s most elemental forces reveal themselves. It is also a little bit freaky, in a Krakatoa kind of way.

The latest explosive exhalation occurred at 6:35 a.m. Wednesday, with a belch of red-hot rock, which fell harmlessly on the northeastern slopes and melted the snow.

The National Disaster Prevention Center in Mexico City reported Tuesday that El Popo’s lava dome was growing in the volcano crater like a teenager’s pimple on the eve of prom night. It warned of significant explosions of growing intensity, large ash showers, and possible mudflows and molten rock coming down the flanks of the colossus.

(Gene Thorp/The Washington Post)

Authorities raised the alert level to high yellow, or 5 on a scale of 7 (with 7 presumably being something out of a Michael Bay film).

At a news conference Tuesday, Interior Minister Alejandro Poire said that “the federal government has all the financial, logistical and human resources to meet any contingency around the volcano.”

Poire said there was no need, at present, for any evacuations of the area. He said that the high yellow alert meant volcanolo­gists were intensifying their monitoring efforts — but that residents should go about their business.

Mexico City Mayor Marcelo Ebrard told reporters that emergency officials were monitoring the volcano but that “at present there is nothing to worry about.”

Volcanologists generally believe that activity like what is now taking place helps a volcano blow off some steam and release pressure, thereby making a cataclysmic eruption less likely — in the same way that a lot of little earthquakes are better than one Big One.

Nevertheless, school has been canceled in three small towns on the volcano’s eastern flanks. The State Institute of Civil Protection also called on people in municipalities near the volcano to stay alert.

El Popo awoke in December 1994 and has been rumbling intermittently ever since. The 17,886-foot volcano has been closed to mountaineers for years, though the adventurous still climb El Popo’s mythical lover, the equally spectacular — but silent — volcano named Iztaccihuatl, which everyone calls Izta.

In 2000, the last time El Popo really let loose, more than 50,000 people were evacuated.