Holiday-season events, including Macy's now-traditional day-after Thanksgiving Day parade, will be the reason for some traffic diversions in the downtown Seattle core on Friday.

Macy's Holiday Parade is scheduled to kick off at 8:45 a.m. from Seventh Avenue at Pine Street. The parade will head west to Fifth Avenue, then south to University Street, then west to Fourth Avenue, and north to the Westlake Center area, on the east side of Macy's downtown flagship store.

The parade route and streets in-between will be closed to through traffic from about 8:30 to 11 a.m. In addition, the exit from southbound Interstate 5 to Union Street, near the Washington State Convention and Trade Center, will be closed from 8:30 to 10 a.m.

Parade planners say up to 35,000 spectators are anticipated.

Later in the day, more than 10,000 spectators are expected to fill Westlake Plaza for the also-traditional Westlake tree lighting celebration, scheduled from 5 to 5:30 p.m. Streets funneling traffic into the plaza will be cordoned off from about 4:45 to 6 p.m.

On Friday, some transit buses in downtown Seattle will be rerouted all day because of the parade and the tree lighting. Regular transit service will be shifted from Fourth and Fifth avenues onto Third Avenue during the event hours, and bus service on Pine Street also will be impacted.