The tornado that tore through the Eastbrook mobile home park near Evansville, Indiana on November 6, 2005 was 1,500 feet wide, moving at 70 mph and producing winds close to 200 mph. Worst of all, the twister struck in the middle of the night while everyone in the park was sound asleep.

The rare November tornado claimed 25 lives in southwestern Indiana including 20 people from the mobile home park. Residents said they couldn’t hear the tornado sirens and had no warning that a powerful storm was headed their way.

Earlier this year, the state of Indiana changed the weather warning process when Governor Mitch Daniels signed legislation requiring all mobile homes sold in Indiana must come equipped with a NOAA weather radio.

Dubbed “C.J’s. law”, for two-year-old C. J. Martin who died in the mobile home park, the new law went into effect on June 30. C.J.’s mom, Kathryn, had urged lawmakers to adopt the bill arguing that a weather radio can give residents advance warning of tornadoes.

Costing from $35 to $70, weather radios broadcast continuous weather information from the National Weather Service. When a weather warning is issued, including a tornado warning, the radio will sound an alarm, much like a smoke detector, alerting residents severe weather is in their area.

Still, the weather radio system is not ideal. Many weather radio owners turn off the device after getting fed up with false alarms and the weekly alert tests issued by the National Weather Service.

The Weather Service hopes a new weather warning system will fine-tune those weather advisories, reducing false alarms and making weather warnings more precise. Implemented last week, the new “storm-based” warning system switches from the traditional county-based warning to a more specific community-by-community alert.

“A storm-based warning focuses on a storm itself and the geographic area that might be affected by it,” said Eli jacks, a meteorologist with the National Weather Service. “We can really reduce the number of people being warned by reducing that geographic area.”

Using radar and computer modeling programs, the National Weather Service hopes to predict the moment a storm will hit a community, neighborhood or crossroad. The new alerts could reduce a warning area from thousands of square miles to a few hundred of square miles.

“It’s like shrinking the service area in a tennis court,” said John Ferree, a meteorologist with the National Weather Service in Norman, Oklahoma and one of the developers of the plan. “Even Roger Federer is going to hit the ball outside the lines if they’re close together.”

A version of the storm-based system has already been in use here in South Florida. When a severe thunderstorm is nearing Belle Glade in far western Palm Beach County, for example, only the communities directly in the path of the storm are put under storm warnings.

The system has worked well here and in trials in Indiana. “I think it has been a good system,” said Dave Tucek, who coordinates severe weather warnings in Indianapolis. “The idea being that there is no reason to warn the northern end of a county about something in the southern end of the county.”

The National Weather Service estimates the new storm-based warning system will save $100 million annually, mainly on cutting back on unneeded business closings or the amount of time people spent huddled in closets or basements during weather warnings.

More importantly, officials hope the new storm-based system will get weather advisories to people who will be directly impacted, giving folks the information and the time to prepare for severe weather.

Maybe with the new, more targeted warning system, folks will be more likely to keep their weather radios turned on, giving them a real chance to survive a tornado like the one that hit the Eastbrook mobile home park.