Via Erik Clemetti's Eruptions blog: New Explosive Eruption From El Salvador's San Miguel. Click through for some good photos, a very dramatic video, many links, and continuing updates. Excerpt:
In somewhat unexpected news, San Miguel (also known as Chaparrastique) in El Salvador had an explosive eruption earlier today — with some impressive images showing up across the internet (see above). Not a lot of details right now, but ash is falling on the towns around the volcano. It is hard to get a sense of scale from the images I’ve seen thus far, but the eruption column looks to be at least several kilometers tall.
[UPDATE: It seems that the plume is being estimated at ~5 km / 16,000 feet. This would suggest to me a vulcanian explosion, but we won't know until the ash is examined to be juvenile (new magma) or accidental (old rocks).]
The civil alert status for the area around the volcano was raised to yellow after the eruption occurred, suggesting that more explosions could follow. No word so far on any evacuations
(UPDATE: 5,000 have been ordered to evacuate from around the volcano).
This would be the first eruption from San Miguel since 2002, when the volcano produced a small VEI 1 eruption. The last large eruption from the volcano came back in 1967, at the end of decade of a number of VEI 2 eruptions from the volcano. The last time the volcano appear in the Global Volcanism Program’s weekly activity report was in 2011, when increasing degassing was noticed. As with many Central American volcanoes, ash fall and pyroclastic flows are major hazards from San Miguel.
More details as they arrive (and if this isn’t enough, Etna has started a new paroxysm as well — check out the webcam.)