The following schools have canceled classes on Thursday, as of 11:30 p.m. Wednesday:

* Ayer-Shirley

* Billerica

* Burlington

* Concord/Carlisle

* Chelmsford

* Dracut

* Groton-Dunstable

* Greater Lowell Technical High School

* Littleton

* Lowell

* Nashoba Valley Technical High School

* North Middlesex Regional

* Tewksbury

* Tyngsboro

* Westford

* Wilmington