Archives: Weather Glossary

Our weather glossary breaks down complex weather and climate terms in an easy-to-understand way.

What is an Atmospheric River?

TWSE Explains

Our atmosphere is constantly in motion. Weather systems are transported around the globe by this motion, with a narrow band of stronger winds called the ‘jet stream‘ providing much of this motion, which lies between cold and warm air masses.

What is Sleet?

TWSE Explains

In the average winter, most of us will have to deal with frozen precipitation, not just snow. One of these types is sleet, and we'll explain how it forms and the difference between it and a hailstone.

What is a Polar Vortex?

Ed Oswald

Winter 2020-21 didn’t turn out as many thought. Most long-range forecasters thought La Niña would lead to a mild and uneventful winter. My weather station read 62 on Christmas Day in Pennsylvania! Well, the polar vortex had other plans.

What is a Nor’easter?

TWSE Explains

Nor'easters are intense periods of snow and high wind that can last for days. While the term is most commonly associated with coastal storms that pass by the Northeastern US' major cities, the term is used elsewhere, such as in Europe.

Cloud Types Guide

Ed Oswald

No doubt at some point you’ve looked up at the clouds, if just for their beauty, and to marvel at the different shapes and sizes. By knowing the various cloud types you can make general assumptions about current and near-future weather.

Sleet vs Freezing Rain vs Hail

TWSE Explains

Sleet vs freezing rain: which winter weather phenomena would you rather deal with? While both create a whole host of headaches, one is far more hazardous than the other.

What are Snow Squalls?

TWSE Explains

It happens every winter. Drivers are caught off guard by icy roads and a sudden wind gust, the arrival of cold air, and a burst of snow so heavy you can't see the car in front of you. It's called a snow squall and is more common than people think.

What is an Outflow Boundary?

TWSE Explains

An outflow boundary is a meteorological term that refers to the boundary between two air masses created by a thunderstorm's downdraft. If you've ever stood outside during a thunderstorm and felt the cool rush of air preceding a storm, you've experienced an outflow boundary.

The Difference Between Isolated and Scattered Thunderstorms

TWSE Explains

When most people think of thunderstorms, they imagine a large, dark storm cloud that pops up in the afternoon and evening, bringing strong winds and heavy rain. This type of storm is called an air mass thunderstorm. However, two other types of thunderstorms often precede frontal passages in the summer.

What is a Squall Line?

TWSE Explains

A squall line is a line of strong and severe thunderstorms common in the spring and summer and often produce strong winds, lightning, heavy rain, and hail. Squall lines often form ahead of cold fronts but can develop independently if several strong thunderstorms merge.