Hurricane Rosa intensified into a major storm in the Pacific Ocean, with maximum sustained winds of 145 miles per hour, the National Hurricane Center said late Thursday.

Swells generated by Rosa are forecast to affect parts of the coastlines of southwestern Mexico, the southern Baja California Peninsula, and Southern California later this week and over the weekend.

"These swells are likely to cause life-threatening surf and rip current conditions," the Miami-based center said.

At 8 PM PDT...Rosa was moving west at 8 Knots. She is now a CAT 4 hurricane, the 7th of the EastPac 2018 season. Maximum sustained winds are 145 mph. Slight strengthening is possible overnight before weakening and turning north Fri into Sat. Large swells are headed our way. #CAwx pic.twitter.com/mTmCKGUF6P — NWS San Diego (@NWSSanDiego) September 28, 2018

The Category 4 storm was moving west at around 7 mph at 2 a.m. ET on Friday.

No coastal watches or warnings were in effect, the NHC said.