It was darkness at noon in the central sierra as Sangay volcanic ash clouds block the sunlight

At 10 a.m., streetlights remained on and vehicles needed headlights to navigate the streets of Riobamba.

It was a morning without sunlight Thursday in Riobamba and other communities in Ecuador’s central inter-valley region as new explosions from the Sangay volcano sent ash clouds more than five miles into the atmosphere. Even at noon, a local radio station reported that “only a fraction of the normal daylight” was passing through the ash and rain clouds.

At 11 a.m., Riobamba was still in the dark.

“This emergency comes at a very difficult time since we are already suffering flooding and road blockages due to landslides from heavy rainfall,” said Carlos Guerra, regional director of the Risk Management Service in Riobamba. “The mix of rain and ash causes special problems as the ash hardens when it is wet and can cause damage to surfaces and machinery.”

In addition to Riobamba’s 400,000 residents, the ashfall affected dozens of smaller cities and towns, including Guamote, Alausí, Chambo and Cebadas in Chimborazo Province. The Geophysical Institute said it was having difficulty projecting the movement of the ash plume due to heavy cloud cover over the entire country. “We depend on satellite images to predict movement of ash clouds and the weather is making this difficult,” an institute spokesman said.

He added that other areas to the west and southeast of Sangay should be on alert for possible ashfall. “Locations such as Guayaquil, Cuenca and Azogues should remain vigilant although there is no immediate danger of spread,” he said. “The volcano is experiencing a series of powerful explosions and this makes prediction very difficult.”

The city of Riobamba issued a morning statement advising residents to remain indoors. “If you must go outside, wear masks and eye protection and be aware that wet ash is particularly dangerous.” The statement said crews are working to clean wet ash off of machinery and storm drains.