A National Weather Service meteorologist says there’s something in Iowa farm fields that’s greatly contributing to the high humidity right now, the crops.Meteorologist Craig Cogil says the crops add a lot of moisture to the air as they grow.Cogil says the other reason it’s so humid is that a weather system is parked over the nation’s midsection.That ridge of high pressure in the upper U-S, allowing warm, humid air to move north from the Gulf of Mexico. Cogil says there may be a little relief in sight: a front will move through the state, bringing cooler air by Wednesday.