Extreme instability, strong shear, lots of moisture…all ingredients were in place over northern Iowa yesterday. The SPC put up a moderate risk in the area, including a 15% hatched area for EF2-EF5 tornadoes. Nothing came of it. A layer of warm air aloft prevented the development of thunderstorms. In fact, not even so much as a rainshower popped up before dark in the region. A good forecasting day, but the atmosphere simply had other plans for the day. All part of the frustration that has characterized chase season 2009. We look eastward today, and the picture is very muddy. We face a very, very long drive through very stormy weather…not the isolated supercells we strive to intercept, but clusters and lines that produce high winds and heavy rain instead. We will play tag with some on our route eastbound today and tonight.