March 8, 2021 – Spring officially arrives on March 20, 2021 at 5:37 a.m. EDT. It’s the Vernal Equinox. Unofficially, spring is already in the air. This week in some northern locations, temperatures will soar into the 60s. There were sub-freezing or sub-zero temperatures for most of February. This week will feel like summer if temerpature rise into the 60s. But Mother Nature always has a few surprises in March. Even though spring migration is underway, will birds be flying in snow?

Temperatures will be 15 to 25 degrees above average over parts of the Upper Midwest on Monday into Tuesday. This information is from this morning’s National Weather Service (NWS) bulletin. Whatever snow is on the ground will have a good chance of melting away.

If there is another March snowstorm, the snow will probably melt quickly as temperatures swing wildly from the 30s to the 60s and even higher. March could easily be called muddy March. It’s often the least favorite month from the standpoint of weather. As snow melts, it turns an ugly brown color. Soggy lawns and fields are also an ugly brown color, basically large patches of mud.

The saving grace for March is March Madness, the NCAA Men’s and Women’s Basketball Championships. And for millions of birders, March means bountiful birds will soon be migrating north during spring migration. Peak migration for beautiful little warblers (songbirds) is early May.

Some birds, such as many species of shorebirds (e.g. ducks, geese and swans), are already on the move.

Vernal Equinox
Seasons change because planet Earth is tilted on its axis as Earth orbits the Sun, a star. The following is an explanation of the Vernal Equinox by the NWS:

“There are only two times of the year when the Earth’s axis is tilted neither toward nor away from the sun, resulting in a ‘nearly’ equal amount of daylight and darkness at all latitudes. These events are referred to as Equinoxes.The word equinox is derived from two Latin words – aequus (equal) and nox (night). At the equator, the sun is directly overhead at noon on these two equinoxes. The ‘nearly’ equal hours of day and night is due to refraction of sunlight or a bending of the light’s rays that causes the sun to appear above the horizon when the actual position of the sun is below the horizon. Additionally, the days become a little longer at the higher latitudes (those at a distance from the equator) because it takes the sun longer to rise and set. Therefore, on the equinox and for several days before and after the equinox, the length of day will range from about 12 hours and six and one-half minutes at the equator, to 12 hours and 8 minutes at 30 degrees latitude, to 12 hours and 16 minutes at 60 degrees latitude.”

Reason for the Seasons
NASA has an excellent graphic to explain why seasons change. Again, to be repetitive to make sure everyone knows why seasons change, seasons change because of Earth’s tilt and not the distance of planet Earth from the Sun.

Let’s count down the days to March 20 and hope there is not a winter swan song!

REVIEW QUESTIONS

1. Why do seasons change?

2. What is the forecast for the Upper Midwest this week?

3. When is the first day of spring?

4. What is the Vernal Equinox?

INQUIRY QUESTIONS

1. How many days does it take Earth to orbit the Sun?

2. Why are there equal amounts of daylight and night on the Vernal and Autumnal Equinox in March and September?

3. Read the headline again. What is the origin of the idiom, “swan song?” Discuss its literal and figurative meanings.