Past IEM Features tagged: gfs
The Ames Airport and much of Ames reported a nice inch of rain on Sunday. This event was not well forecasted by the weather models and the featured chart shows precipitation forecasts from the GFS model. Each small box represents the three hour forecasted precipitation for one model run for one three hour window in the future. This model runs four times per day and forecasts out for a number of days, so thus why you see so many boxes! The left most highlighted area shows few GFS model runs showing rainfall for Ames for the period it actually rained (top row of boxes) on Sunday. The second highlighted period shows very heavy rainfall persistently forecasted by the model for Monday night and into Tuesday morning. Hopefully the model is not wrong about this upcoming event.