Estimating Hail Size For Midwest States

The National Weather Service has established a criteria for a severe storm that includes a hail size of ≥¾ of an inch in diameter, except for the Midwest where the size is ≥1 inch in diameter. A study was done at the National Weather Service site in Chanhassen, MN where they used the height of the freezing level, -20°C dbZ, 60 and 65 dbZ heights, and storm top divergence to establish a calculator that notifies the meteorologist whether to warn for severe weather or not and gives an estimate of hail size. This work uses the calculator on other states within the Midwest in order to determine if the calculator can be as affective as it is in Minnesota. The hail size will vary since the calculator was based on previous Minnesota storms but it should yield relatively similar hail sizes to the observed sizes along with being helpful in warning for severe weather.