It’s mid-November, and temperatures are getting cooler and days are getting shorter. Certainly, both are factors in making things a little depressing. The cold keeps us inside, and the lack of daylight makes things dark, quite literally.

But even in the daylight, it can often seem more grim. When it’s sunny, that usually means it’s colder in the morning, but another huge factor is the lower Lifting Condensation Level (LCL) that comes with winter. The LCL is level at which air lifted from the surface would reach the condensation point in the atmosphere. In practice, this is the height at which the bases of clouds form.

A given “parcel” of air will see temperatures drop at a known rate with height, based on established atmospheric physics. As we know with fog and clouds, moisture can only be retained in air to a certain temperature before it condenses. This is also why we have dew in the morning – that is when temperatures are coolest, and the air can’t hold the moisture any longer.

Cold air holds less moisture, and the atmosphere is colder in at all levels in the winter. As air at the surface is generally warmer than air aloft, it is prone to rising until it meets the LCL, at which point clouds start to form. Clouds are more likely in the cooler weather because the air can’t hold moisture, and the LCL is lower because the change in temperature from the surface to the point which the air can’t bear as much water is smaller, so those clouds are going to have low bases. There will be more clouds, and they will be lower to the ground. It’s dingy and claustrophobic, even in the day time.

But at least night comes earlier. At least spring is only 6 months away.