PORTLAND — Superintendent Jim Morse has canceled school Wednesday in Maine’s largest school district in advance of a major snowstorm.

Morse also canceled after-school activities this afternoon because of today’s snowfall, though tonight’s school board meeting is still set for 7 p.m. at Casco Bay High School.

Wednesday’s storm is expected to start in the early morning hours and bring 9 to 18 inches of snow, according to weather services.