AMES, Iowa -- Another round of severe thunderstorms over the weekend that produced large hail--grapefruit-sized in parts of Eastern Nebraska, and some inch-and-quarter hail in Eastern Iowa.
"We've had three or four severe weather events already in the storm season that ended up dropping at least one- to two-inch hail stores causing damage in sort of the same general area. I have not seen this in my roughly 30 years living in Ames," says Iowa State University Meteorology Professor William Gallus.
He says severe storms producing large hail may be coming from a rapid transition between "La Nina" and "El Nino" weather phenomena in the Pacific Ocean.
"Perhaps because of these changes that are going on globally we've just been in a position in Iowa where a lot of very powerful weather systems have been setting up--putting Iowa on the east side of the really strong winds, which is a good location to get severe weather," Gallus says.
He says that rapid "La Nina" to "El Nino" transition also makes it hard to say if the large-hail pattern will continue for the rest of the severe weather season.
"Three events, or even just one year, that ends up being extra active is not enough time to really study it and to be able to tell if it's a long-term trend. I know right now the weather has become rather cool and is generally pretty quiet for the next week or two," Gallus says.
Severe thunderstorm producing large hail, strong winds and tornados in some parts of Iowa has prompted Governor Kim Reynolds to issue seven different disaster declarations since the end of March.