Category Archives: weather

  Now and then, usually in the winter, one sees some cloud that is strikingly blue. It is cloud that is only receiving direct illumination from the clear blue sky—neither from the Sun, nor higher clouds. I am always impressed … Continue reading →

  In which, something normally hidden is disclosed: a thin layer of snow reveals internal structure. The same is true of frost and dew. I first became aware of these things as a student when I discovered a book (Geiger, 1957, … Continue reading →

  Anchor ice (also called bottom-fast ice) is ice attached (anchored) to the bottom of a stream. At first blush, it seems rather odd that any ice should form on the bottom of a water body. After all, for ice … Continue reading →

  This morning, Kootenay Lake was a devils’ playground. It was spellbinding to watch, but also tooth chattering and bone chilling. Within easy sight, dozens upon dozens of devils frolicked. The experience was bone chilling as the temperature was about … Continue reading →

  Snow is white—which is really just to say, it is the same colour as the light source. But, white on a tree does not require snow—frost is white; so is rime. We have had extensive rime on mountain slopes … Continue reading →

  Steam fog There are two distinct processes that may lead to the formation of cloud or fog. One is vapour cooling; the other is vapour mixing. Steam fog results from the second: two volumes of vapour with different temperatures and … Continue reading →

  You can stick your finger into a glass of water, but not through a block of ice. That pretty well explains what is going on in this morning’s picture of fallstreaks. Water molecules are not as tightly bound together … Continue reading →

  I don’t get to see the parhelic circle very often. It is usually faint—albeit unmistakable—even on the few occasions it appears. The best recent show was over a year ago when the sky displayed not only a parhelic circle, … Continue reading →