SAN ANTONIO  —  The National Weather Service will stop issuing countywide severe weather warnings this fall, instead putting out warnings that are more geographically specific, the National Oceanic and Atmospheric Administration said Tuesday.

The weather service will issue "storm-based warnings" for tornadoes, severe thunderstorms, flash floods and marine hazards for specific areas within a county, using well-known landmarks such as highways or rivers.

Severe weather warnings are currently issued for entire counties.

Retired Air Force Brig. Gen. David L. Johnson, director of the weather service, said the new warning system, which will take effect Oct. 1, will provide the public with better information.

"These are potentially deadly, short-duration events that can develop very rapidly," Johnson said at a news conference during the American Meteorological Society's annual meeting.

Because of the current system, some people could be under a warning but be more than 100 miles from the weather event, he said. In Texas, some counties are bigger than the state of Rhode Island, he noted.

The change will improve graphical displays and offer more accurate information to the public so areas that aren't threatened won't be warned, he said.

"This is a fundamental change in our warning procedures and a major enhancement in our service capability," Johnson said.