A day earlier, Roman Abramovich’s yacht My Solaris arrived in the nearby resort of Bodrum, triggering a protest by a group of Ukrainians.
Khashoggi, a contributor to the Washington Post, was killed on October 2 shortly after entering the kingdom's consulate in what Riyadh called a "rogue" operation.
The US mission is closed this week as Turkey celebrates the Muslim holiday of Eid al-Adha.
Heavy rainfalls that pounded the Black Sea coastal provinces of Bartin, Kastamonu, Sinop and Samsun on Wednesday caused the flooding that demolished homes and bridges and swept away cars.
The statement is the first public confirmation by a Turkish official that Khashoggi was strangled and dismembered.
Muharrem Ince, Erdogan’s main challenger in the latest election, while conceding defeat after the results were announced, had warned that Turkey was becoming "a one-man regime”.
A 75-year-old woman was found dead amid the debris of her three-story house in Rize's Muradiye district, state-run Anadolu Agency reported.