2017-03-20 09:21:00.000 – Taylor Regan, Weather Observer
Today, March 20th, is a glorious day. Let me tell you why. It is the first day of spring! Or, to be more specific, it is the Vernal Equinox, and generally regarded as the first day of spring by most (meteorologists excluded).
The March Equinox heralds spring in the Northern Hemisphere, and fall in the Southern Hemisphere, and is the point where day and night are just about equal in most time zones around the world. The Equinox is celebrated at the same time across the globe, regardless of time zone, and is reflective of the point at which the Sun crosses the celestial equator. At that point in time, the Earth is neither tilted towards nor away from the sun.
This year, the Equinox occured today, on March 20th, at 10:29 UTC, or 6:29 am EDT at Mt. Washington. It is interesting to note that the exact date of the Spring Equinox can vary between March 19, 20, or 21.
For the Northern Hemisphere, spring lasts from the Vernal Equinox until the June Solstice, which marks astronomical summer. Meteorologists, like those up here on the summit, consider the 1st of March as the beginning of Spring, with the season lasting until May 31. This is partially to keep records consistent, by avoiding the year-to-year variation of the Spring Equinox date.
March equinox celebrations occur all around the world, and the day is generally regarded as beginning a season of new life. One superstition holds that you can balance an egg on its end on the equinox. Many ancient monuments were built as astrological calendars, mapping the sun movement over the course of the year.
Fun Fact: Looking to the sky today, you might see the moon in the daylight sky prior to it setting at 11:32 am. Maybe you have wondered in the past why the moon, when visible in daylight, almost appears translucent. Why is this? Referring back to my earlier comment on the colors of sunrise and sunset, Rayleigh scattering is largely responsible for this phenomenon. What you are seeing as you look towards the moon in the blue of the sky as it is scattered from the sunlight. This reflected blue light is in between you and the moon, as a result you are seeing the parts of the moon that are reflecting the sun brightly enough, but the rest that appears translucent is lost through the scattered blue light, making it appear that these parts blend in to the sky.
What does the Vernal Equinox mean for the summit here? Well, you’ve maybe heard the expression, “in like a lion, out like a lamb” regarding March’s weather, hinting that March starts fiercely in the throes of winter, and exits in the calm and rebirth of spring. Well, up on the summit here, winter’s fury has a tendency to linger well into spring (and even sometimes summer, for that matter). But by taking a look at some of our weather stats from the beginning of this month, you can bet the summit staff is ready for a little reprieve!
Throwback image of sunrise on the first astrological day of spring, March 20, 2016
As it stands currently, the summit’s average temp for the month of March is a frigid 1.8 degrees Fahrenheit, that’s a whopping 11 degrees below average! Not only have we seen a cold start to the month, but also a windy one. Our average wind speed for the month to date is 49.3 mph, which is almost 10 mph above average (of 40.3 mph). Our snowfall, though we are only about halfway through the month, is just about at our monthly average, (43.7 inches and 45.1 inches, respectively), and our liquid equivalent is just about average for this time of the month at 3.73 inches out of the 7.67 inch monthly average.
Taylor Regan, Weather Observer