The first Atlantic hurricane of the season is forecast to bring heavy rain and life-threatening surf and rip currents to the U.S. East Coast this week.

While the category 4 storm is not expected to make landfall on the U.S. east coast, it will have an impact nonetheless.

Most of Erin’s intensification occurred during a 12- to 15-hour window overnight, according to Dan Pydynowski, a meteorologist at AccuWeather. By 5 p.m. Friday, Erin’s winds had remained only 75 mph.

Additional strengthening is expected as the storm is forecast to “remain a large and dangerous major hurricane through the ...