Incorrect units of precipitation
Whithin the maps of thunderstorms and precipitation the unit of the amount of precipitation are given in liters per square KILOMETERS.
This should read in liters per square meters!
This layer is called Thunderstorms. It shows the area where there are lightning risks, not rain.
l / km2 means lightning per sq kilometer
Click the small circled i in right bottom corner on desktop or About this layer in the mobile app to get information about layers: