The Japan Weather Association (JMA) has been struggling with a cyberattack that has been ongoing since Thursday morning. Their website, tenki.jp, is currently inaccessible due to a DDoS attack, which bombards a website with so much traffic that it can't function properly. This is just the latest in a series of cyberattacks targeting Japanese companies. Airlines, mobile carriers, and banks have all been hit recently. The JMA hasn't said when the website will be back online, and they also experienced a similar attack last Sunday. They apologized for the inconvenience, especially considering the current risk of heavy snowfall.
I use Tenki.jp regularly. Sadly, the app still takes over a minute to open.