Omaha Public Radio News
1:45 am
Mon March 9, 2009

NWS changing one criteria for issuance of Severe Thunderstorm Warnings

Omaha, NE – The National Weather Service is changing one of the criteria that determines if a Severe Thunderstorm Warning is issued.

Right now, one of those warnings is issued if a thunderstorm contains 58 mile-per-hour winds and three-quarter inch diameter hail. Starting April first, the hail criteria will change to one-inch diameter. The decision was made by the National Weather Service based on a multi-year study of hailstorms in Kansas. The NWS' Central Region offices, including Omaha, are making the change.

NWS Valley meteorologist Barbara Mayes says the difference between three-quarter inch hail and one-inch hail is the difference between a penny and a quarter. She says the National Weather Service found that three-quarter inch hail didn't cause significant damage unless it was driven by very strong winds.

Mayes says the change in hail criteria could lead to fewer Severe Thunderstorm Warnings and more Special Weather Statements being issued.