On the weekend of San Francisco’s annual Bay to Breakers race that typically brings tens of thousands of people to the city, the National Weather Service is asking folks to stay away from the beaches due to hazardous conditions.

San Francisco is expected to see wind gusts up to 50 miles per hour throughout the weekend, National Weather Service meteorologist Roger Gass told SFGATE on Friday. The wind will be blowing across the region from west to east — so for runners going from downtown to the ocean, it means they’ll likely face a headwind all throughout Sunday’s revelrous race. 

But beyond the actual running, the wind will also cause a major impact on the Pacific Ocean. The weather service put out a statement on Thursday warning of hazardous beach conditions, with the gusts likely leading to rocky seas, bigger waves and cooler water temperatures — even as temperatures reach into the 70s.

“Our ocean is definitely not family-friendly, and the water is cold,” Gass told SFGATE. “Even if the weather is hot, it doesn’t mean that the ocean is warm.”

The 12-kilometer race ends along the Great Highway right alongside Ocean Beach, with a festival after the finish line set up at the southwestern corner of Golden Gate Park near there. Some racers celebrate finishing the race by jumping into the ocean water, but Gass said he would “highly discourage people who are wanting to jump into the water after the race.”

Bay to Breakers spokesperson David Perry told SFGATE on Friday that race organizers are continuing to monitor weather conditions for Sunday’s race and will send participants an alert about race conditions sometime before Sunday’s 8 a.m. start. But they haven’t done so as of Friday afternoon, partly in hopes of a pattern change before the race begins. 

“As we all know, the weather in San Francisco can change in 10 seconds or 10 blocks,” Perry said. “So we’re all hopeful it’s going to be a nice, dry and calm day for the 115th running of Bay to Breakers.”

Perry also encouraged runners to officially register for the race and to download the official Bay to Breakers app to get the most up-to-date information about the race.