Gas prices are jumping at the pump. Over the past week, prices in the Lake area have increased by anywhere from 15 to 20 cents. In some other places around Missouri, gas prices have risen by as much as 30 cents. Triple A says some of the blame is because of refinery issues in the northeast, west and south. Refineries are also said to be at the start of their maintenance season. Another reason is the recent increase in crude oil prices from 92 to 100 dollars a barrel.