At 12:57pm EDT on Thursday, the Earth will hit the vernal equinox. It's the point where the Earth's axis is at a near 0° incline in relation to the sun (the planet's vertical axis is normally tilted in relation to the sun, but not during the 2 Equinox's a year). Above is a picture from Wikipedia explaining the Equinox a little bit better than I can with words. The best part about the Spring is we are now on the count down to summer, and the longest amount of daylight during the year on the Summer solstice!
The temperatures are going to be decent for the start of Spring. We will be right around average for highs on Thursday, generally in the upper 50s. Friday looks simply amazing with plenty of sunshine and highs in the mid to upper 60s. However Winter hasn't had it's last laugh yet my friends.
A big trough in the jet stream will dip into the Eastern half of the country as it has done so many times this Winter. This is going to allow a ton of cold air to come back down and stick around for a couple of days from the weekend into next week. Check out what the GFS is showing for departure from normal temperatures for Saturday through next Thursday.
That's showing temperatures about 6° Celsius below average, that would translate to highs in the mid 40s and lows in the mid 20s. While not as cold, it looks like another cooler period could be waiting for us not long after. This what the GFS is looking like from March 30 through April 4th.
There's still a lot of cold in mother nature's tank my friends.