Mount Redoubt, a volcano 100 miles from Anchorage, Alaska has blown its top and is erupting, nearly two months after experts predicted it would.

The eruption started at 11:38 p.m. Sunday local time but was obscured by darkness and snow. The height of the initial burst is believed to be 0,000 ft, with a warning of bursts to 50,000 ft. Notably aircraft between Asia and the East Coast of North America pass in the vicinity for fuel stops on their trips. For example, Hong Kong to Toronto stops in Anchorage. Alaska Airlines is reported to have turned back four flights bound for Anchorage to their cities of origin.

An ash cloud warning is in effect for Anchorage, with ash expected to land at 2am local time across the entire Anchorage area.

Scientists had upped their warning of an eruption in the 12 hours before it happened after a series of some 60 odd small earthquakes in the area.