SPRINGFIELD, Mass (WWLP) — Record high temperatures are in the low 90s Saturday across western Massachusetts, and with actual temperatures in the 80s, combined with the sky high humidity levels, it felt like that record.
Despite the nice weather, a big change is coming starting Sunday. The shift is primarily due to a rapidly changing jet stream.
The western United States is noticeably less humid because the eastern Pacific Ocean’s sea surface temperatures are much cooler, and cooler water leads to cooler air which leads to less humidity.
The western Atlantic Oceanic is very warm, and therefore feeds a lot of moisture to the eastern half of the United States.
Saturday, the jet stream was positioned in such a way that it’s dragging in hot air from the southwest, while swinging north in such a way closer to the coast that it’s also picking up that Atlantic moisture.
Sunday, however, the jet stream curve will instead feed in air from over the Arctic. Air that is not only cooler, but significantly drier.
That will bring temperatures slightly below normal.