Two big storms are coming to Japan. They are now over the ocean. The storms are moving north. They will reach Japan in days. Weather experts are watching them closely.
Two Storms Approach Japan, With Possible Convergence Complicating Forecasts
Easy
Sometimes two storms come very close. They can push away from each other. They can also follow each other. The worst thing is they combine into one. Weather experts call this the Fujiwhara effect.
This makes weather guessing very hard. Teams must plan for many things. People on the coast may need to leave. Everyone is getting ready now.
Sources: japantimes.co.jp