weather

All posts tagged weather

Credit UuMUfQ – CC-BY-SA


Cloud of the Day – Nimbostratus

I mentioned nimbostratus in the Cloud of the Day post on altostratus, but I think it deserves a post of its own. It is a stratiform cloud that typically forms on a warm front. As advancing warm air rises over the retreating colder, denser air, we see the classical progression of cloud types. As the warm front approaches, we see the highest clouds first. Wisps of cirrus, maybe a layer of cirrostratus, complete with a halo, and cirrocumulus. Then, the closer the warm front gets, the lower the clouds we see. The middle etage clouds, altocumulus, and altostratus, perhaps even altocumulus castellanus, are next. Finally come the stratocumulus, stratus and the various forms of cumulus.

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It is the stratus clouds that are of interest in the case of nimbostratus, because nimbostratus is so thick that it stretches from near the ground up into the middle etage. It is stratus and altostratus combined into one thick layer. It is so thick that its bottom is very dark, even black. It is so laden with water that precipitation is inevitable. The “nimbus” in the name has many meanings, but in the case of the cloud, it indicates that it’s a rain cloud.

Credit Indrajit Das – CC-BY-SA


Nimbostratus is the cloud that gives sustained rain over a wide area. It is the bringer of those dark, gloomy, wet days. Often there are fractus clouds scudding about underneath it. It’s the kind of weather that’s good for the lawn, and good for watching from inside, warm and dry.

Credit Fir0002 – CC-BY-SA


rjb

“Enchanted Light | New Mexico” by Jim Crotty is licensed under CC BY-NC-ND 4.0

Spring and early summer have been good so far this year. It has been unusually cool and wet. The numbers haven’t been extreme. We have seen months at 125% of the average. The wettest, June, was 150%. We can’t say that it’s been twice as wet as usual, even though it feels as if we should be able to. I suspect that is because it has been so much wetter than the last few years, which have been quite dry.

I can see the effects right out my window. The lawn and trees and other plants in our yard are green and luscious, without the need for a lot of irrigation. The hillsides across the valley still have a lot of green on them, which is unusual in july. The biggest and most important effect, though, is the dramatic decrease in forest fires. In the last couple of decades there have been a lot of fires, many of them large and dangerous. By this time in July there would have been hundreds of fires with tens of thousands of hectares burned. This year there have been fewer than two hundred with less than a thousand hectares burned. That shows that most of the fires have been small, extinguished before they could take off. For that we can thank the weather for keeping things wet.

This isn’t what tourists expect to find when they come to the Okanagan, but most of us who live here appreciate ti.

rjb


After the snow and the cold snap, we have cycled into a warm spell. Looking at that picture, would you believe I live in a desert? It’s not only warm here, it’s also wet. Everything is sodden and dripping, but I like it. We need to stockpile as much moisture as we can at times like this against the threat of drought later in the year.

rjb


That was the cold snap. Minus fourteen the first night, following a biting north wind that froze our doorknob on that side. Temperatures hovering near that mark for a couple of days, not changing much between day and night. Much colder not far north of here. I guess we just caught the southern fringe of the arctic outbreak. Snowing today and forecast to warm up over the next few days, all the way above freezing.

Guess what I heard:

“Cold enough for ya, yet? So much for global warming, eh?”

A thousand years of data won’t convince them, but one cold snap will. Although, I guess it could be a harmless bit of amusing banter and not indicative of the speaker’s political leanings, couldn’t it? Just a bit of humor. Gallows humor, maybe.

Those clothes that were on the line in the last post sure got freshened up in that wind. The shirt I’m wearing — the plaid one — smells like fresh air.

Go see the rest of the Jesus and Mo cartoon to find out how they got to that point.

rjb


Here’s the snow that was forecast, along with some wind. North of us are snow plows working hard, snowblowers roaring in driveways, cars that look like white humps in the snow. Here you can clear the driveway with one hand on the shovel. It’s still warm, though. Around freezing. Next up, the cold snap.

rjb