Did the CIA really send a notice to the Catalan police warning of a possible terrorist attack in Barcelona?

The Catalan authorities and the Mossos d’Esquadra police deny they received any CIA warning that ISIS was potentially planning an attack on Barcelona’s La Rambla. A Catalan newspaper, El Periódico, on Thursday printed a memo allegedly sent by the US intelligence agency to Catalonia’s police force via the American National Counterterrorism Center (NCTC). However, the Catalan home affairs minister, Joaquim Forn, claimed on Thursday that the Mossos receive “dozens” such warnings and analyze them all.