CHELMSFORD -- Leave some extra time for your commute this morning, as the heavy rain has already caused some accidents on the busiest travel day of the year.

A "minor accident" has shut down the left lane on Interstate 495 North at exit 33, resulting in a backup on the way to Lowell.

In addition, Lowell police reported a three-car crash at Andover Street and Clark Road, which caused a traffic jam this morning. Cars were towed from the scene, but there were no injuries, according to police.

The heavy rain is expected to last into busy the afternoon and evening commute. Flood and wind advisories are in effect for Lowell.

Follow Rick Sobey on Twitter and Tout @rsobeyLSun.