LISBON — Web Summit, one of the world's largest technology conferences, has cancelled its second day in Lisbon on Wednesday after the Portuguese government ordered the event shut because of Storm Charles.

"The Government of Portugal has formally advised Web Summit that, due to the risks posed by Storm Charles, including tidal flooding, severe disruption to public transport and the impact of high winds on external structures, Day 2 of Web Summit should not take place," organizers told attendees in an email.

The decision followed discussions with the Portuguese government, the National Emergency and Civil Protection Authority and the Public Security Police. "Web Summit will of course respect the Government's direction, and accordingly, Day 2 (Wednesday, November 11th) will not take place," the email said. The summit plans to resume on Thursday.

Portugal has declared a state of alert for the whole of mainland Portugal, closing schools and non-essential public services for Wednesday. Access to coastlines, riverside areas and other flood-prone locations has been prohibited, and Lisbon has closed road tunnels, parks and museums.

Storm Charles is expected to bring winds of up to 140 km/h, heavy rain and possible coastal flooding, with red weather warnings in place for Lisbon and seven other districts until 9 p.m. Wednesday. The storm has already caused flooding in Madeira's Machico region.

Lisbon Mayor Carlos Moedas had suggested on Tuesday that the summit should be cancelled, leaving the decision to the central government and organizers. Web Summit, held at the MEO Arena and the FIL exhibition centre in Parque das Nações, expects close to 70,000 attendees, including 900 speakers and more than 2,000 startups, from more than 150 countries.

The four-day conference opened Monday and is scheduled to run through Thursday, Nov. 12.