Scientists received indications that the Turrialba volcano was about to erupt again about 10 p.m. last night, but the cloudy condition of the area prevented them from seeing what was happening.
The Red Sismológica Nacional said that instruments detected an episode of tremors within the mountain from 9:25 to 9:52 p.m. Such activity usually comes before an eruption of ash, the Red said.
There were no initial reports of ash falling, said the Red.
The mountain is watched closely, but only infrared cameras are able to pierce the thick cloud cover. The wind was southwest, said the Red.
The mountain has erupted dozens of times in the last five days.