This example shows traditional word spacing. The amount of space between each word is equal to the amount of space that it would take to write the letter i.
When you leave more space it can be distracting. When the word spaces line up in a vertical or diagonal line, it looks like a river of white space flowing through the paragraph.
I circled the *rivers* and spaces with a red pen to point out the areas I am talking about.
I inserted the letter i in three places to show how much closer the following words should be. The slant on the i between the-snowfall is way off. Please ignore that detail and just look at the amount of space.