Experts said that addressing five basic areas can help companies ride out a storm: ensuring computer-system redundancy; having access to phone service and the Internet; alternative power sources; insurance for storm risks; and delegation of post-storm duties to employees.

Be redundant

Businesses commonly guard against the risk of power outages on their premises by backing up their computer systems. Many have turned to automated online processes that regularly back up, or replicate, their computer systems on external hard drives in remote data centers, collectively known in high-tech shorthand as "the cloud."

Some businesses use the older, more cumbersome routine of putting backed-up versions of their computer systems on disks or tapes, then trucking the backups to remote storage facilities they control. "There’s nothing wrong with that, the only problem is, it becomes very costly," Dosal said. Nevertheless, "some people want to keep stuff in their facility. They don’t trust the cloud" due to security concerns or other reasons. "Even some of the largest companies, they’re not sending their stuff up to the cloud."

In a hurricane zone, however, keeping a computer system and its replicated twin in the same office is riskier in many respects than storing the twin separately in a storm-proof bunker. That’s one reason why many businesses in South Florida have turned to the cloud, or bunker-style data centers with fortified space, where tenants install equipment to back up their home-office computer systems.

Related services usually are available, too. Some data-center operators, for example, provide limited seating and Internet connections inside their facilities on an emergency basis to employees of powerless client companies.

Users of smart phones can prevent the loss of photos, phone numbers and other bits of personal stuff on these devices by backing them up to a cloud with the help of such remote-storage operations as iCloud and DropBox.

"All our emails and contacts are on a cloud. We use Microsoft 365 for that," said Robert Plessett, managing partner of TeleSwitch, a Miami company that sells integrated telephone, video conferencing and surveillance systems to commercial clients. "So if I don’t have power here, if I don’t have Internet access, I can go someplace else and I can still get my emails on my phone."

Terremark, a Miami-based subsidiary of the wireless telecom carrier Verizon, operates one of the most connected data centers in the world, the carrier-neutral, 750,000-square-foot Network Access Point (NAP) of the Americas in Miami. Leading telecom carriers and Internet service providers have connected more than 140 countries by co-locating switching equipment at the multi-tenant NAP, which also serves as a remote, secure location for computer-system backup.

"To build and operate your own data center is the most expensive option," said Tom Mays, senior vice president of advanced data solutions at Terremark and head of its disaster recovery business. "Customers can save a significant amount using the cloud . . .  The benefits of the cloud come from the fact that it is multi-tenant. We’re running multiple customers on the same infrastructure, and everybody is getting kind of a cooperative benefit."

Mays advises business managers shopping data centers to ask questions about their security systems and procedures and about their track record in actual disasters: "Is the provider not just an infrastructure provider but also a disaster recovery expert? Is it somebody who has a lot of scar tissue around what can happen in a real disaster situation?" He also said it’s helpful to know the density of a data center’s connections to carriers of telecommunications and Internet traffic.