Gas prices in Iowa have jumped about eight cents a gallon in the past month according to the latest state survey. Ward Lenz of the Iowa Department of Natural Resources says pump prices are about a quarter higher than a year ago. The average Iowa price for a gallon of unleaded with ethanol is a $1.46. Lenz says it’ll be a “topsy, turvy spring” with price spikes in gasoline prices ahead.He says a refinery in Illinois is rumored to be going out of business, and Lenz says that refinery supplies about one-third of the gasoline in Iowa. Lenz does not predict gasoline shortages, but he says the shutdown will probably mean higher pump prices.