Agencies use old and new tech to monitor, prepare for Hurricane Earl

As Hurricane Earl barrels down on the East Coast of the United States, federal agencies are relying on a combination of new and established technologies to prepare for and to monitor the massive storm, including gadgets that more accurately measure wind speed and social media sites citizens can use to communicate and relay information.

The National Hurricane Center and Federal Emergency Management Agency have worked together to reduce the chance that Earl doesn't catch communities and local governments by surprise.

"We have all kinds of tools, some of which we've had a long time, and others more recent," said James Franklin, branch chief of the hurricane specialist unit at the National Hurricane Center in Miami.

Traditional satellite images are the "single most important" piece of data because they track a storm's movement, but they "are increasingly supplemented by newer tools [arming] aircrafts that help us do our job better," he said.

The National Hurricane Center uses a new instrument called the Stepped Frequency Microwave Radiometer to classify a hurricane's wind force. The equipment picks up the microwave radiation emitted from the foam the hurricane winds create on the ocean's surface. Earl's top winds have been measured at 135 MPH, making the storm a Category 4.

"The windier it is, the more disrupted the sea surface and the greater the amount of foam," creating more radiation, Franklin said. "That's kind of a big deal because until recently we had to estimate the intensity of a storm based on the winds observed by an aircraft," flying at 10,000 feet through the hurricane. "Of course, no one lives at 10,000 feet," he added. "We need to know how strong the winds are at the surface."

For about 10 years the National Hurricane Center has used a device called a dropwindsondes to measure a hurricane's winds. The instrument is loaded with a GPS receiver and a parachute, which opens when dropped from an aircraft. Scientists can measure wind speed based on how fast a dropwindsondes descends. While the center still uses the device, it's less reliable than Stepped Frequency Microwave Radiometers because it measures wind only in a specific location. In addition, dropwindsondes costs $750 each and can't be reused.

"Having continuous readings below where the aircraft is flying allows us to have better estimates of current [storm] intensity, which is the starting point for a forecast," Franklin said. "You can't forecast something unless you know what you're starting from."

Meanwhile, FEMA also is relying on technology to prepare residents for the possibility of Earl. The agency has used social media sites to keep citizens in Puerto Rico, the Virgin Islands and on the East Coast of the United States informed about the storm, which is expected to sweep up the U.S. shoreline starting near Cape Hatteras, N.C.

FEMA's Facebook page provides updates on Earl's intensity and movement in English and Spanish, and directs visitors to Ready.gov, which provides information on preparedness and response to hurricane emergencies, and also refers them to the National Hurricane Center's website for updates on Earl's status.

In addition, FEMA and the National Hurricane Center are offering mobile versions of their sites that are designed for cell phones' small screens and for handheld devices.

"Our most important message is for people to be aware, and make sure they've taken steps to plan for [emergencies] before the storm threatens," said FEMA Administrator Craig Fugate during a media call Tuesday.