Sep. 22, 2015: The start of the Fall season, as known as the Autumnal Equinox, is tomorrow morning. Our weather will be anything but fall-like, however!
More on that in a second; first, here’s how the fall season begins:
The Earth has a slight wobble going as it spins on its axis through space. That change in angle gives us our seasons; in the spring and summer, the northern hemisphere is tilted toward the Sun, giving us more intense sunlight, which heats us up more. In the fall and winter, the opposite happens, with us tilting away from the sun, weakening the energy provided by the Sun, which cools the Earth off on our end.
When the equinox occurs, the Earth’s axis is roughly straight up and down, placing the Sun directly over the equator. We mark that as the start of the Fall season (it also happens in the spring, when we are tilting back toward the Sun). This year’s Autumnal (i.e. Autumn, or Fall) Equinox occurs at 3:21 AM CDT.
It is somewhat of a myth that day and night are equal on the equinox. This is close, but not exact. Since light bends as it’s coming into the atmosphere (this causes the sky to be blue, plus provides beautiful colors as the sun angle changes during sunrise and sunset), there is a delayed effect to having equal portions of night and day. It will take until this Saturday before we have an “equal” day.
So what’s ahead for the Fall season? For starters, Fall 2015 will be off to a very warm start. Temperatures will be nearly 10 degrees above average as an unseasonably warm weather pattern this week stays strong into Wednesday and beyond.
We will eventually cool off some, but maybe not a lot: the Climate Prediction Center is showing a good chance for above average weather to last through December. We’ll still get some cold days, but if you average the entire Fall season together, we should end up somewhere above average for temperatures.
So, who’s ready for Fall? It looks like a beautiful start to the season, at least this time around!
Posted under weather