In a flash, it can tell if there may be a flood

It can portray a hurricane in stunning detail. It’s powered by a supercomputer that can perform 14 trillion calculations a second. And starting in June, it should help tropical meteorologists project whether a storm will arrive as a killer or a cream puff.

The sophisticated model could be the tool forecasters have long sought to sharply improve their hurricane intensity predictions and give emergency managers and residents more time to prepare accordingly.

“This is the first time a hurricane model will have its own analysis of the center of the hurricane’s structure,” said Naomi Surgi of the National Weather Service, who spearheaded the model’s development. “This is really pushing the frontiers of science.”

“Often times, the intensity forecasts can be poor, and that’s not because forecasters aren’t doing the best they can,” said John Gamache of the National Oceanic and Atmospheric Administration’s Hurricane Research Division in Miami. “It’s just that, to an extent, our understanding of the processes within a storm are kind of limited.”

Enter the new model, officially called the Hurricane Weather and Research Forecast system, or “H-werf” for short. It will zero in on the ocean’s interaction with a storm as never before and produce an elaborate three-dimensional picture of a hurricane’s core, where the most vicious winds lurk.

Hopes are that it will outperform older storm-intensity models, said Surgi, hurricane modeling program leader at the weather service’s Environmental Modeling Center in Camp Springs, Md.

To function, the model needs to gorge on data: sea surface temperatures, wind conditions and barometric pressures, gleaned by planes, satellites, buoys and other sensors.

After the information is gathered, it is processed by NOAA’s supercomputer in Gaithersburg, Md., which is capable of absorbing 240 million global weather observations daily and doing 14 trillion data operations in a flash.

The model already has proved to be a powerful forecasting tool. While being tested, it accurately predicted that Hurricane Katrina would spin into a Category 5 monster as it moved across the Gulf of Mexico toward New Orleans in August 2005. It did a “really good job” tracking other major hurricanes that summer, including Dennis, Rita and Wilma, Surgi said.

Nevertheless, it will take a few seasons for forecasters to gain confidence in the model, she said. Though it should produce positive results this year, it will require annual upgrades before it becomes a truly reliable gauge of a hurricane’s development.

“We will see an accelerated rate of improvement over the next five to 10 years,” Surgi said.

NOAA, the parent agency of both the weather service and the hurricane center, has made intensity forecasting a priority because the Atlantic basin is entrenched in a period of heightened activity. That was clearly seen in 2005, the most destructive and active season since records began in 1851.

The fear is that more hyperactive seasons may lie ahead, and that off-target intensity predictions could lead to disaster. Yet, try as they might, forecasters have so far been unable to grasp the complex mechanisms that influence storm strength. As a result, the hurricane center last year erred by an average of 21 mph in predicting the sustained winds of storms three days in advance. That wasn’t much better than the average error a decade and a half ago.

The most dreaded scenario for forecasters and emergency managers is for a system to rapidly intensify just before landfall, as Charley did in August 2004. In five hours, the system’s sustained winds surged from 110 to 150 mph, from Category 2 to Category 4, before battering Punta Gorda, Port Charlotte and other southwest Florida towns.

The reason Charley bulked up so quickly: It crossed over unusually warm water near the coast and feasted on the thermal energy.

It’s just the kind of information the new system is designed to detect and take into consideration.