I’ve always been one to ponder the small scientific puzzles in life, even when there are much bigger events going on in the world like the COVID pandemic.
For example, why does the Chemainus Valley gets less sunshine on average than Thetis and Penelakut Islands at certain times of the year? Maybe these ponderings are just how I handle stress or boredom, depending on the situation.
Certainly I have concerns about the pandemic and I’m trying to do everything the health experts are saying we should do to protect my health and the health of my family, and I too am wondering just how long the crisis will last. I’m very much struck by the fact this is the first time in history nearly the entire human population of Planet Earth is doing the same things at the same time under conditions of near total lockdown.
At the same time, though, I’m also wondering if May will bring another early start to summer as it has for the last half decade or so. If so, should I be happy about it, or should I be increasingly concerned about the global warming that’s probably the cause of the longer summers and stormier winters we seem to be getting these days?
Now there’s something that’s faded from the public discourse during the current health crisis. Just a year ago, climate change was a big concern and the World Meteorological Organization was at the centre of the debate trying to promote measures to counteract its negative effects.
Now it’s the World Health Organization, a sister agency at the United Nations, which is front and centre trying to promote measures to counteract the effects of the pandemic. Kinda makes an old weather guy like me a bit nostalgic for the good old days!
If my interest in the weather seems a little obsessive to some, whether it’s cloud-spotting or debating whether the seasons should be defined astronomically or meteorologically, it’s likely because I have a bit of an obsessive personality. For me, anything worth doing is worth doing to excess! Some may think I have obsessive-compulsive disorder, but when I look at all the chaos in what commonly passes for “mainstream culture”, I prefer to see my condition as obsessive-compulsive “order”, even though it may drive some people crazy.
So now back to that question I started with, just in case anyone is curious about it: Why does the Chemainus Valley get less sunshine than Thetis and Penelakut Island, especially during the spring season? These two small islands can get as much as two hours more sunshine per day than the rest of us, mostly during the late afternoon or early evening hours before sunset.
We can thank the Vancouver Island mountain ranges for that, an effect that can operate on two levels. The most obvious factor is Thetis and Penelakut are further away from the mountains than the Valley, so it takes longer for the end-of-day shadows cast by the mountains to reach them. However, that only accounts for about a half hour difference in sunshine.
A much bigger factor when weather conditions are favourable is the cloud cover that forms over the mountains (sometimes referred to as “orographic” cloud) with the prevailing westerly winds that bring humid air in from the Pacific Ocean. As this moisture-laden air is forced aloft passing over the likes of Mount Brenton, the water vapour condenses into clouds that can cast a much more extensive shadow than the mountains that produce them.
Typically, the westerly wind circulation carries the clouds about as far as the channel that separates the Chemainus Valley from the smaller Gulf Islands. That’s usually about where the clouds evaporate before reaching Thetis and Penelakut Island, leaving them bathed in sunshine during the hours before sunset while the Chemainus Valley remains grey under the spell of the Island Mountain Cloud Factory.
Fortunately, I have a way to manage if I get into a grey mood due to too much cloud cover here. I just look beyond those sunny Gulf Islands to Vancouver. I can’t see our big city neighbour directly from here, but I can often see the clouds and weather they get due to their proximity to the Coast Mountain Range.
Vancouver gets a lot more of the grey stuff than we do much of the time, so I don’t reckon we have much to complain about. Of course, not all our clouds are orographic. We also get a fair amount of local marine cloud that forms over water, and clouds that are created by organized weather systems that roll in from the Pacific, both of which are much more democratic than the mountain clouds when it comes to grey weather. Those latter clouds blot out the sun nearly everywhere.
Next question, when is this pandemic going to end? Sorry, I can’t help you with that one.
(Chris Carss is a Chemainus resident and long-time weather observer/recorder).