The National Weather Service Jacksonville escalated Jacksonville Beach's rip current risk to high Tuesday, warning that life-threatening currents are likely through late Thursday night.

Surf Expected to Build Through Thursday

Surf was already running 3 to 4 feet Tuesday afternoon with northeast winds of 15 to 20 mph, according to the NWS surf zone forecast issued at 11 a.m. Conditions are forecast to worsen.

The agency projects surf of 4 to 6 feet Wednesday, with northeast winds around 20 mph and gusts reaching 30 mph. Thursday's forecast calls for similar surf heights with northeast winds around 20 mph. Under the NWS definition, a high rip current risk means life-threatening currents are likely in the surf zone.

Forecast Marks Sharp Reversal From Saturday

The escalation marks a sharp reversal. The NWS rated Jacksonville Beach's rip current risk as moderate Saturday, with surf of just 1 to 2 feet. That forecast's extended outlook had already signaled the coming surge, projecting surf of 5 to 7 feet for the following Wednesday. The current forecast revised that estimate slightly downward to 4 to 6 feet.

Advisory Covers Northeast Florida, Georgia Coasts

The high-risk advisory covers the Northeast Florida coastline, including Nassau, Duval, St. Johns and Flagler counties, as well as the Georgia coast in Glynn and Camden counties.

Calmer Seas Expected by the Weekend

Conditions are expected to ease heading into the weekend. The NWS forecast shows surf dropping to 3 to 4 feet Friday and 2 to 3 feet Saturday, with winds falling to around 10 mph. No official all-clear has been issued.

Officials Urge Swimming Near Lifeguards

Lt. Maxwell Irvanian of Jacksonville Beach Ocean Rescue stressed the importance of swimming near lifeguards in a Sept. 7 interview with Action News Jax. "We always tell people never swim alone, always swim with a buddy," Irvanian said at the time.

Water Temperatures Remain Warm Through Advisory

Water temperatures remain warm, forecast at 80 to 85 degrees through the high-risk period. Beachgoers can check updated conditions at the NWS beach forecast page at weather.gov/beach/jax.