Fig. 10.1. Photo of the weather sensor suite at the Iowa DOT maintenance garage in
For the case studies presented here a technique is used to derive the actual snowfall from
the light emitting diode weather identifier (LEDWI) sensor located at the METAR site.
The LEDWI sensor reports once per minute during times of falling precipitation. In
order to convert the liquid precipitation measurements to snowfall accumulation a snow
to liquid ratio must first be identified. Time periods with relatively light winds were used
because they had fairly good liquid precipitation measurements from the NWS tipping