Past IEM Features tagged: aviation
The primary purpose of the weather stations (ASOS + AWOS networks) located at airports is to support aviation! Besides measuring wind speed and direction, these stations also make important observations of horizontal visibility and an estimate of cloud coverage at altitude. The combination of these later two observations are lumped into four categories that generalize the flying condition. The featured chart displays the hourly flight category as computed by the hourly observations from the Des Moines Airport. VFR (Visual Flight Rules) are the best conditions for flying and for allowing many variants of pilots and flight. This category has dominated for the month with only a few hours on the 2nd in a less favorable category.