Missing American in Dominican Republic: Unpredictable ocean currents, beachfront pose major search challenge

Her last known whereabouts came in the early hours of March 6, headed to the beach at the five-star Riu Republica resort in Punta Cana.

Everyone else seen going to the beach with her is accounted for. She never returned.

The resort has been flying red flags for days - indicating strong currents and big waves.

Even when the green flag is up - safe waters - conditions can change without warning, according to Yuri, a local charter boat captain.

"In the Caribbean, all of a sudden the wind comes," he told Fox News Digital. "You have to always be vigilant."

Many of the beaches have netting installed to keep swimmers safe and keep out floating seagrass. However, portions of the beach are unprotected, including several sections of the beach behind the Riu.

The currents are also unpredictable, experts say.

"Punta Cana is located on the Mona Passage, which connects the Caribbean Sea and the Atlantic Ocean between the Dominican Republic and Puerto Rico," explained FOX Weather meteorologist and digital content producer Andrew Wulfeck, who examined coastal records from around the time of Konanki's disappearance. 

"As is common where two waterways meet, the swell can be erratic and difficult to forecast, unlike the more predictable patterns often seen on beaches along the U.S. East Coast."

Because of the predictability of the coastline of the mainland United States, he said, authorities know that if someone is washed away, they will typically be carried to the north.

"Unfortunately for authorities on the island of Hispaniola, the erratic nature of the swells there means it is impossible to predict where items may wash up, necessitating the need for heightened vigilance from all beachgoers," Wulfeck said.

On the morning of Konanki's disappearance, swells of between 4 and 6 feet were coming from the north and east, he said. However, in the following days, they shifted toward the east and south.

"Let's say, for instance, she was caught up in a rip current, she could have been dragged out and then the current could have carried her somewhere else," he said. "A nearby buoy in the Mona Passage indicates water temperatures are in the low to mid-80s, which can help support a person who might be stranded on a flotation device without the threat of immediate hypothermia."

While early reports suggested she may have drowned, experts say they believe she would have washed ashore or been found by now if that were the case. Authorities are officially urging the public not to jump to conclusions as the investigation unfolds.

They have identified and questioned a person of interest in the case, an American college student who was the last person seen with Konanki the morning she vanished, but it has not been deemed a criminal matter. It is currently a missing person investigation.

The classmates and another man were seen returning to the hotel around 6 a.m.

Hours later another man, believed to be the person of interest, returned alone. Konanki has not been seen again.

Her friends reported her missing around 4 p.m.

Police have spent days searching the coastline with boats, dive teams and helicopters. The FBI is involved, and the sheriff from her Virginia hometown said he would be sending two detectives to assist in the investigation.

Fox News' Audrey Conklin and Stepheny Price contributed to this report.