National Weather Service Weather Forecast Office

On April 1st, the hail size criteria the National Weather Service in Sioux Falls and surrounding offices use to issue Severe Thunderstorm Warnings will change.  Instead of penny size or three-quarters of an inch, the new threshold will be a minimum of quarter-size or one inch in diameter.  There will not be a change to minimum wind gusts needed for a warning, which is 58 mph (50 kts).

For more information on the background behind this change and implementation plans across the Midwest, please watch the five minute video below. 

One-Inch Hail Informational Video