The forecasters at the National Hurricane Center are the calm voices before the storm. Even off camera, they speak in a steady register, giving no indication that they are in the path of a violent tropical cyclone.

With Hurricane Irma headed toward Florida, the forecasters have been working around the clock, updating storm tracks and issuing watches and warnings — not only for this killer storm but also for two other hurricanes, Jose and Katia.

This is life-or-death stuff. People have to decide whether to evacuate. Florida has ordered evacuations for nearly 6 million people as the entire state has been imperiled. The Coast Guard, the National Guard, the Federal Emergency Management Agency, the Pentagon and the White House all hang on every word and data point from the people here at the center.

And yet, acting director Ed Rappaport remains unruffled.

He says, mildly, "I'll be looking forward to a quieter period."

Irma's journey from the remote Atlantic Ocean through the Caribbean and toward Florida's southern tip has affirmed the improving forecasting skills of the meteorological community and shown that storm prediction remains an inexact science.

The storms are much more likely to go where the experts say they'll go. Twenty years ago, Rappaport said, the hurricane center had a "1-2-3" rule — meaning that a day out, the forecast of the storm track was likely to be, on average, incorrect by 100 miles. Two days out, it would be off by 200. Three days, 300.

Today, the two-day forecast is on average within 70 miles, Rappaport said.

"We've cut out two-thirds of the error of the track. That was science and technology," he said.

The practical consequence is that the center now issues a five-day forecast rather than merely a three-day forecast. That gives people more time to prepare. For residents here in Miami, it also has prolonged the frantic period in advance of the storm. People began making a run on stores and gas stations and buying up the last plane tickets out of town on Tuesday, for a storm that isn't expect to reach Florida until Sunday.

Forecasters here have repeatedly stated that people shouldn't focus heavily on the precise center of the forecast storm track. The experts have tried to normalize uncertainty, and make people comfortable with margins of error, which is why the "Cone of Uncertainty" has become a regular feature on projection maps in their advisories.

The center's website explains: "Historical data indicate that the entire 5-day path of the center of the tropical cyclone will remain within the cone about 60-70% of the time."

The National Hurricane Center remained Saturday within the Cone of Uncertainty. The center, which is on the campus of Florida International University in west Miami-Dade County, has been bashed by a hurricane before. In 1992, the center was located in an office building on U.S. highway 1 in Coral Gables, across from the University of Miami.

Rappaport was a young forecaster at the time and remembers being so engaged with the high-pressure job of putting out the 5 a.m. forecast for Hurricane Andrew that he didn't notice that the building was swaying until a colleague pointed it out.

The storm knocked the radome, the domed structure over the radar, off the roof of the building. A wind gauge measured a gust of 164 miles per hour.

"There were cars flying through the air," Rappaport said. "I was relatively new and didn't know what to expect from a hurricane, let alone a Category-5 hurricane."

With Irma approaching, the center has remained a remarkably calm environment. The top forecasters take turns speaking to television stations and networks around the country, and they tend to speak in a neutral, just-the-facts tone.

Mark DeMaria, the center's acting deputy director, employed the same deadpan tone when asked how he feels about Irma. Betraying no emotion, he said, "I'm very concerned about this one."

DeMaria moved to South Florida three years ago and bought a house in the western suburbs, which is what you expect from someone who spends a lot of time talking about storm surge.

"I was thinking maybe it's a little bit nicer to the east, but I'd prefer to live a little further from the beach," he explained.

The hurricane center looks like a hurricane center, with three radio antennae aiming skyward on a side lawn and a forest of dishes on the roof. A stray cat name Pit patrols the exterior. The cat eats a lot, hence the name. The security guards say they're making sure there's a way to shelter Pit during the storm.

An interior hallway is lined with vintage newspaper front pages, hurricane-themed cartoons and photographs of major hurricanes from space. Peek into an office and you'll see loaves of bread and jars of peanut butter and jelly. It's government work, and survival food is pretty basic.

The spokesman here, Dennis Feltgen, is a former TV weatherman.

"I was one of the very first TV meteorologists out there screaming in the wind," he says.

Feltgen said he sometimes asks his colleagues to be more demonstrative when they're talking to the press or recording advisories for the public — but "they're scientists" he said.

Born in 1952, Feltgen grew up in Florida back when hurricanes seemed to blow through Florida every couple of years. He said he was sound asleep when Hurricane Cleo's eye passed right over the house in 1964.

"My dad put masking tape on the plate glass windows," he says. "Yeah, dad, right."

After all these years in the hurricane business, he still has one regret: As a weatherman chasing hurricanes, he was never in the eye of the storm.

And if Irma holds its current track — with the eye heading west of Miami — he'll have to wait longer.