Category Archives: weather

  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 →

  The trouble with rainbows is, frankly, all that rain. Within minutes of my camera begging me to take it out to see the rainbow, we both were soaked. I could not wipe its lens quickly enough to keep drops … Continue reading →

  For the last week I have delighted in the adornments accompanying mountain waves. Just as a moving boat will leave waves in its wake, so too can a mountain—although in this case, the air moves, not the mountain. Unlike … Continue reading →

  The interaction of the Lake and a sandy beach offers fascinating physical details: Water wets the sand changing both appearance and firmness. Waves move up and down the beach sorting sand and pebbles by size. Waves shift sand along the … Continue reading →

  After a few weeks of low cloud and rain, the skies cleared overnight. The inevitable result of moist ground, moist air, and radiative cooling was valley fog. Fog blanked the Lake. It gently drifted over the water and along the shore. … Continue reading →

  The skunk will have to wait. Last evening I managed to take the first good picture of a foraging skunk in a long time. I was about to post it, when a circumzenithal arc appeared in the sky. Nature’s … Continue reading →

  We have entered the season of the circumhorizontal arc—one of the most brilliant and colourful of all the haloes. Indeed at its best, it outclasses the rainbow. The circumhorizontal arc forms a horizontal line low in the sky, when … Continue reading →

  The title is not a typo: this is about sky lines, not skylines. White lines across the sky are easy to interpret: contrails (trails of condensation from aircraft). What about dark lines across the sky, such as seen in … Continue reading →