The window in which severe thunderstorms could pummel New Orleans and Baton Rouge Saturday is becoming smaller.

Multiple St. Patrick’s Day celebrations in South Louisiana have been postponed due to the threat of strong winds and possible tornadoes this weekend.

The worst of the weather is expected Saturday afternoon and should end between 6 p.m. and midnight, the National Weather Service said. Waveland’s annual St. Patrick’s Day Parade will now roll at 2 p.m.