A trough - ridge setup in the U.S.

The U.S. is experiencing a textbook example of a trough-ridge pattern and record heat and record cold are coming in with it.

As you can see on the TemperatureRadar, cold temperatures have overtaken the western U.S., and spring-like warmth is spreading across the east. This pattern will be in place for the next several days too!

The trough and ridge pattern is in place high up in the atmosphere, as much as 20,000 feet into the sky, and is influencing our outfit choices all the way down here on Earth’s surface. Some are wearing more layers than usual – hello, SoCal – and many are putting on sunscreen in the Midwest!

This pattern not only influences our temperatures here at the surface but also the type of weather.

Ridges are made up of high pressure which means the average weather at the surface is fair and usually quiet. Sometimes showers can sneak in due to lower-level disturbances, but on average, residents can expect quiet skies.

As for the trough, this is made up of low pressure which is associated with rainy, snowy, and even stormy conditions. The West is experiencing just that with heavy rain and mountain snow on top of the colder temperatures.

The meeting point between a trough and a ridge can also bring eventful weather. We’re seeing that tonight and Friday with the severe weather risk across the central and southern Plains.

So how do the cold and warm temperatures get brought in? This has to do with the circulation. A low-pressure trough spins counterclockwise and pulls cold air southward from the north.

The opposite takes place in a high pressure. This spins clockwise and brings warm air from the south northward, allowing the mercury to rise.

This pattern will stay put over the next several days bringing more cold air into the West and warm into the east. Across the West on Friday, thermometers will only be reading into the 40s and 50s for many with cold teens and 20s in the mountains.

At the same time, Manchester, Maine, has the chance to reach 70 F, possibly beating the 2015 record of 68 F. Lexington, Kent., could come close to tying the 78 F record from 2015 with their forecast high of 77 – 20 degrees warmer than the average November temperature here!

No matter where you’ll be this weekend, check the TemperatureRadar for the latest forecast!