Japan - Recent unstable weather in Kanto

Hailstorm around Yokohama station, Kanagawa, today.
http://matome.naver.jp/odai/2133662691840157201

Tornadoes in Tsukuba, Ibaraki, MAY 6.
http://matome.naver.jp/odai/2133628166904762101

Government is still advising being on alert for tornadoes.
At least, take your umbrella with you.

This been a common theme lately?

I remember seeing crosswind landing videos from NRT last month. Amazing stuff.

http://www.youtube.com/watch?feature=player_embedded&v=zwIXeT0EZSQ