WCBI WEATHER WORKS – SPRING ARRIVES

Tuesday will bring the beginning of astronomical spring, but us meteorologists have been in spring since the beginning of March, but why is there this discrepancy? We explore it in this week’s WCBI Weather works.

Astronomical vs Meteorological spring. What’s the difference?

Generally when people think of seasons, they tend to think of astronomical seasons.These are based on the sun’s relation to the earth. The year is then divided roughly into fourths based on the solstices and equinoxes. The spring equinox occurs around March 21st and is when the sun passes directly over the earth’s equator. Because the earth’s orbit is an elliptical shape, seasons vary between 89 and 93 days. This inconsistency created problems with climatological data.

Therefore meteorologists break the calendar into fourths based on annual temperature cycles. The warmest 3 months are deemed as summer and the coldest 3 months deemed as winter. Using this basis, Meteorological spring runs from March 1st through May 30th. This allows us to compare seasonal temperatures to one another more easily.

But just because we’ve entered into a warmer season doesn’t mean the cold is gone for good. Historically here in Mississippi, freezing weather can least well into April and even May and our average last freeze is in late March. It is also possible to see snow as late as the beginning of April. With this weeks WCBI weather works, I’m Meteorologist Amanda Reynolds