Good morning on this cloud-shrouded Wednesday.

This morning, instead of attending his usual seminar on United States government, Andrew Myers will address those in power.

Mr. Myers, a senior at the Packer Collegiate Institute in Brooklyn Heights, is one of tens of thousands of students nationwide who will walk out of classrooms today to protest gun violence, following the killing of 17 people at a high school in Parkland, Fla., a month ago.

Roughly 1,000 Brooklyn students are expected to rally in solidarity today at Borough Hall, according to Mr. Myers, one of the event’s organizers. Dozens of schools in all five boroughs have registered to take part in walkouts as well.

Most of the students involved are too young to vote. Until he turned 18 in January, Mr. Myers was one of them — an impetus for his civic engagement. “This is our only outlet,” he said. “We can’t do anything other than protest.”