Story highlights

NEW: The National Weather Service issues an ashfall advisory

Latest readings say ash plume has risen to 37,000 feet -- nearly double previous height

The Pavlof Volcano, on Alaska's remote Aleutian Island archipelago, last erupted in 2014

CNN  — 

Alaska’s Pavlof Volcano, which erupted unexpectedly over the weekend, continued to rumble and fling ash into the sky Monday, the Alaska Volcano Observatory said.

The ash plume is now 37,000 feet high and trails some 400 miles to the northeast over the Alaskan interior. Aviation alerts were up in the region.

Citing Kristi Wallace, a geologist with the observatory, CNN affiliate KTVA reported that the main concern is the ash cloud that has been growing since the eruption and obscuring area air traffic.

Bering Air and PenAir canceled at least some flights Monday, according to KTVA.

Wallace reportedly said she doesn’t expect ash to fall, except for trace amounts in the village of Nelson Lagoon.

The National Weather Service issued an ashfall advisory for communities north and east of the volcano, including Nelson Lagoon, warning of light accumulation less than one-tenth of an inch.

The volcano began erupting suddenly Sunday. It’s the first eruption for the volcano since 2014.

Pavlof, which is about 7 miles in diameter and located 592 miles southwest of Anchorage, is described by the center as “one of the most consistently active volcanoes in the Aleutian Arc.” In the past, it has sent ash plumes as high as 49,000 feet, according to the observatory.

Fast facts: Volcanoes

CNN’s Dave Alsup contributed to this report.