Ground deicing of aircraft require the use of holdover tables. These tables have specific holdover times based on precipitation intensity and type. Current methods to estimate the intensity of snowfall operationally use visibility to estimate the snowfall rate. Studies conducted at NCAR have shown that visibility can provide misleading estimates of snowfall rate, however. These studies have been corroborated by additional studies by APS Canada. Outdoor and indoor deicing fluid testing has shown that fluid endurance time is indirectly proportional to the liquid water content of the snow. Therefore, methods are needed to provide liquid equivalent snowfall rates to pilots and ground deicing personnel in real-time.

The current Weather Support to Deicing Decision Making (WSDDM) system uses liquid equivalent snowfall rates from snowgauges to calibrate radar data in order to accurately nowcast snowfall rate. The new system is based on WSDDM technology but also includes an additional snow sensor at each airport site, as well as a stand alone precipitation type sensor. These additional sensors make the system more suitable for the determination of holdover time. The purpose of this paper is to describe the development of this standalone liquid equivalent snowfall rate system and the plans for testing at Denver, Minneapolis, O'Hare, and Pittsburgh airports. Preliminary results from the deployments will be given.