Younger Futhark
Hagall is hail, called the coldest of grain in all three traditions: something that arrives looking like the crop and then destroys the crop. Somewhere in these seven days a thing will land that nobody could have priced in, and the rune's most useful claim is that you did not cause it. Þurs has something hostile behind it and Kaun has been developing quietly for a while. Hail simply falls. The Norse poems leave it as cold grain and driving sleet and never follow it through to melting, so do not wait for the week to hand you the lesson. Arrange the seven days so one wrecked afternoon cannot take the rest of them with it.