The spring equinox is here

On Tuesday, March 19, at 8:06 p.m. PST, spring will officially arrive across the North American continent. The date is also known as the spring equinox, and this occurs at the exact same moment across the globe. This is also the astronomical beginning of fall for residents in the Southern Hemisphere. The word “equinox” comes from the Latin words meaning “equal night.”

As I’ve mentioned in previous articles, we have four seasons because the Earth is tilted on its axis by approximately 23.5 degrees. As we move into April and May, the daylight hours become noticeably longer and during the summer, our planet is tilted toward the sun, resulting in longer daylight hours and a higher sun angle. During the equinoxes, the first day of spring and the first day of fall, our planet is positioned on the orbital plane where it is not tilted toward or away from the sun.

Although the equinox means that the Earth will experience exactly 12 hours of day and night, the reason the times are not exactly 12 hours apart on the first day of spring and fall is complex. Our location in a particular time zone, elevation and the fact that the sun is not a singular point in space are some of the explanations.

Here in Coeur d’Alene, March 17 was the day when we were close to having 12 hours of day and night. On that date, sunrise was at 6:55 a.m. and sunset was at 6:56 p.m.

The fall and spring equinox do showcase some of the most incredible works of civilizations around the world. One of the most famous is the pyramid in Chechen Itza on Mexico’s Yucatan Peninsula near Cancun. The Kukulkan Pyramid, also known as El Castillo, is certainly an impressive structure that was built thousands of years ago and is listed as one of the Seven Wonders of the World. The staircase of the region’s highest structure has 91 small steps and at sunset of the autumn and spring equinox, a body of light will form in the shape of a serpent on the pyramid and move down its steps to eventually reach the carved head of the serpent called Kukulkan. There are plenty of videos showing this event on the Internet and people from around the world will come to see this incredible event in person. Back in 1991, Cliff and I were in Cancun for a seminar and climbed the massive pyramid. It was quite a task, but officials no longer allowed tourists to climb the structure due to previous injuries from those who fell.

Perhaps the most famous ancient structure celebrating the equinoxes and the winter and summer solstices is England’s Stonehenge. During the first day of summer, or the summer solstice, the sun will align perfectly with the giant heel of Stonehenge. Researchers believed that this structure was built to use the sun to track the seasons.

There is also a legend that one can balance a raw egg only during the equinoxes. In my younger days, I thought that was the case as I tried many times to balance an egg on a table. I was never successful, but some readers let me know that they were able to do it. According to an article by the Farmer’s Almanac, the feat can be accomplished at any time of the year, provided you have the patience.

In terms of our local weather, the 2023-24 snowfall season is winding down, but I wouldn’t take off those snow tires yet, especially in the outlying areas. Despite the very springlike conditions we enjoyed this last weekend, weather patterns across the western U.S. are expected to change once again to the colder side of the meteorological scale.

By the middle of the week, the sunshine will be replaced by clouds and rain showers. Temperatures will be getting colder at the end of the week leading to a chance of rain and snow showers in the lower elevations. In fact, the full moon lunar cycle that begins March 25 is pointing to a chance of measurable snow in Coeur d’Alene and surrounding regions. Daytime temperatures during this cycle still may be too warm, but there be some accumulation during the overnight hours that could take our seasonal total to nearly 50 inches. Our normal snowfall for the season in Coeur d’Alene is 69.8 inches and the original prediction made last October was 51.4 inches. It was a below-average season for snow thanks, at least in part, to the warmer El Niño sea-surface temperature pattern. Our snowfall total to date is 47.1 inches at Cliff’s station, with 31.6 inches at the Spokane International Airport.

The spring season is expected to start a little wetter than average across the Inland Northwest before having near to below-normal rainfall. There should be occasional thunderstorms that could bring some heavy rainfall. Temperatures in April and May could turn warmer than normal as ocean temperatures in the south-central Pacific Ocean are still higher than average. The upcoming summer is forecast to be another dry one, especially early in the season.

• • •

Contact Randy Mann at randy@longrangeweather.com.