CHICOPEE, Mass. (WWLP)- 90 degrees in September is quite out of the ordinary, considering the weather rarely gets warmer than 60 degrees this time of year.
There’s a certain weather pattern that’s causing the heat.
The jet stream, an area of strong winds high in the sky that helps to guide storms and separates air masses, has taken a major plunge through the western half of the country, also known as a “trough.”
It allows cooler air to drop in, bringing a September chill and even some reports of snow over the past week.
To the east we have a ridge, where the jet stream is forced way north of us, allowing for a surge in heat from the south. No surprise, given this setup, for temperatures about 20 degrees above average for this time of year.