The Doppler Radar for Airport Weather (DRAW) system, which has been installed at eight major airports in Japan, is a detection and warning platform for airport terminal weather hazards such as low altitude wind shear. The DRAW system in Japan is serving as a very important safety net for air travelers.

On Japan railroads, wind conditions also affect operating efficiency, infrastructure, and safe passage of people and freight. For instance, strong winds cause regional delays or shutdowns, and especially hazardous crosswinds may lead to overturn of railcars. Since sonic/cup anemometers densely cover on the railroads for operations through some wind speed thresholds (e.g., winds in excess of 30 ms-1), localized but hazardous wind phenomena are difficult to detect with the present system. The ultimate goal of the project is to develop an automatic hazardous wind alert system for railroads, which the decision to warn is generally based upon information from a single-Doppler radar wind observation.

For the first step of the project, in order to assess the utility of Doppler radar for use in operational railroad systems, high-resolution observations of hazardous wind phenomena over the Shonai area (roughly 20km*20km, Yamagata Pref., Japan) have been performed. The observations include;

1) 26 Automated surface stations which are fairly uniformly distributed in the study area. The instruments measure pressure (10sec intervals) , temperature (10sec intervals) , relative humidity (10sec intervals) , and wind direction and speed (1sec interval).

2) Two Doppler radars (X-band). The distance between these radars is 10km and dual-Doppler scanning is conducted.

3) GPS-sonde soundings within a 3 hour interval from a research vessel located 10km from te shore in the study area.

In this presentation, we will introduce an overview of the project as well as highlights from a sample of ongoing case studies.