Currently, the alerts for tornadoes, severe thunderstorms and flash floods are issued to entire counties. But Maricopa County, for example, measures more than 9,200 square miles, so that can be problematic.
Starting Monday, the Weather Service will issue what it calls storm-based warnings. These will show the specific meteorological threat area, and do not adhere to geopolitical boundaries.
On a map, storm-based warnings will appear as boxes over the areas expected to be hit with nasty weather.
This change is taking effect nationwide.
For more information about storm-based warnings, visit the National Weather Service at www.weather.gov/sbwarnings.