Despite Tuesday's snowfall, the St. Patrick's Day parade will go on. This is Boston, after all.

However, Sunday's parade through South Boston will proceed on an alternate "snow" route. (This is, of course, not the first time the more than 3-mile route was cut nearly in half.)

Mayor Marty Walsh announced Wednesday that the annual parade will start at 1 p.m. at the Broadway MBTA Station and end at Farragut Road. (Here's a map of the original route — the upper half of the route along Broadway will stay intact.)

"Our No. 1 priority will always be to keep our residents safe at all times," Walsh said in a statement. "The snow route has allowed for a safe and enjoyable celebration in other years when there has been heavy snow before the parade."

The modified route keeps the parade out of side streets that the mayor says are difficult to navigate after the snow storm.

"Yesterday's snowfall makes it more difficult to manage this weekend's parade in South Boston, and it has created a situation where we do not feel that it is safe enough for children and families to watch the parade, especially on side streets, which are already difficult to navigate after a storm," Boston Police Commissioner William Evans said Wednesday.

The blizzard on Tuesday dumped about 15 inches of snow on the city — beating Boston's earlier record for snow accumulation in a single day in March. Most area schools were closed Tuesday, and many still on Wednesday as the region dug out from the storm.

The weather for Sunday is expected to be sunny, but quite cold with a high near 34, says meteorologist Dave Goldbaum. The MBTA's Red Line will be running an altered schedule to avoid congestion at Broadway station.

According to the mayor's office, the Boston Public Works Department removed 1,800 cubic yards of snow from Broadway so far and will continue to remove snow and clear sidewalks ahead of the parade.