FARGO — Windy winter weather is made much worse when there is ample snow on the ground. with enough wind, an old snow cover can be lifted into the air, producing whiteout conditions as bad as if it were actually snowing. Without falling snow, these so-called ground blizzards are typically much worse in open country because buildings and trees catch the windblown snow and improve the visibility in their wake.
Ground blizzards are a nightmare to forecast, because it is very difficult to predict the wind's ability to lift old snow and make it airborne. Snow cover has a lot of air in among the snow crystals and so old snow cover is always somewhat compacted. Sometimes it has even melted and refrozen, creating a crust. Enough wind can still break loose the snow and cause a blizzard, but knowing just how much wind is required is sometimes not much more than a guess.