Manufacturing overhead consists of only indirect product costs. Some companies even refer to it as indirect overhead.. Others call manufacturing overhead by the label, factory overhead. Indirect costs cannot be easily traced to specific products or services provided. Because period costs have no relationship with products, they are never labeled as direct or indirect.
The United States averaged 1,274 tornadoes per year in the last decade. April 2011 saw the most tornadoes ever recorded for any month in the US National Weather Service's history, 875; the previous record was 542 in one month.
Tornadoes can happen at any hour of the day and any time of the year, though they are most common in the spring, especially during May and June. They are least common in the winter because cold air has less energy.