Visualized on Google Maps is wind data from the numerical weather prediction model GPV (meso scale model) by Japan Meteorological Agency at the surface level and the upper levels. You can see the wind data all over eastern Japan centered on Fukushima Daiichi nuclear power plant of Tokyo Electric Power Company (TEPCO). Moving the slider shows you the past and the future of wind direction and speed. Winds in the upper atmosphere is available at World-wide Real-time Wind Maps.
This page was integrated into a more advanced World-wide Real-time Wind Maps. However, the surface level wind is still available at Wind Map around Fukushima Daiichi Nuclear Power Plant (Google Maps Tiling Version). Weather information around nuclear plants is also available at SPEEDI radiation monitoring and weather information around nuclear facilities (in Japanese), such as Fukushima Daiichi Nuclear Power Plant. In the same way, Active volcanoes in Japan (in Japanese) shows wind direction and speed around Japanese volcanoes.