For those bracing for cold weather, the frigid temperatures and snowfall of winter 2024 are on their way. Whether you’re prepared or not, information about winter storms, blizzards, nor’easters, bomb cyclones, and lake-effect snow will soon be relevant.

Have you got your shovel ready? (And what do all these terms actually mean?)

Forecasts suggest that snow may come in heavy bursts this winter, particularly in the Great Lakes region, northern Rockies, and Pacific Northwest, although predicting any given snowstorm more than a few days ahead is difficult.

Here’s a guide to understanding winter weather terminology:

What qualifies as a blizzard?

Did you know that the National Weather Service defines a blizzard in a specific way?

A blizzard is classified as a storm with blowing and/or falling snow, with winds blowing at 35 mph or more, which reduces visibility to a quarter mile or less for at least three hours.

Interestingly, heavy snowfall and extreme cold aren’t necessary to meet the definition of a blizzard. (There are instances where strong winds lift previously fallen snow, resulting in what is known as a ground blizzard.)

However, in everyday conversation, the term “blizzard” is often used to describe any major snowstorm with strong winds, according to the American Meteorological Society.

What exactly is a nor’easter?

Nor’easters are substantial, intense low-pressure systems that generally form off the East Coast during late fall, winter, and early spring.

The name “nor’easter” arises because these storms often bring strong northeast winds as they propagate northward along the Atlantic Coast.

Nor’easters frequently lead to heavy rainfall, substantial snowfall, and significant coastal flooding.

Many nor’easters can also create blizzard-like conditions, particularly across New England.

What is a bomb cyclone?

A bomb cyclone is a type of severe winter storm that forms through a phenomenon called bombogenesis.

Often likened to a “winter hurricane,” a bomb cyclone occurs when a storm undergoes rapid intensification, with its central pressure dropping by at least 24 millibars in 24 hours. The lower the storm’s pressure, the more intense it becomes, according to The Weather Channel.

Many of the most powerful winter storms that strike the country’s coasts have been bomb cyclones.

What is lake-effect snow?

When snowfall accumulates in locations like Buffalo, New York, or Marquette in Michigan’s Upper Peninsula, conversations about lake-effect snow often arise. But what is lake-effect snow, and how does it occur?

Lake-effect snow can last anywhere from a few minutes to several days and forms from narrow bands of clouds that appear when cold, dry air moves over a large, relatively mild lake.

As the chilly air flows over the unfrozen, “warm” waters of the Great Lakes, heat and moisture are picked up by the lower atmosphere, according to the National Weather Service. This causes the air to rise, resulting in the formation of clouds that develop into narrow bands, leading to snowfall rates of 2 to 3 inches per hour or even more.

This type of snow commonly occurs in the fall or early winter before the lakes freeze. (However, if the lakes do not freeze, lake-effect snow can persist throughout the winter and into spring.)

Understanding Winter Storm Warnings and Watches

The National Weather Service issues specific alerts to indicate potential severe winter conditions: A Winter Storm Watch is announced when there is a “chance for significant and dangerous winter weather within the next 48 hours.” This does not guarantee that severe winter weather will happen, only that it could happen.

On the other hand, a Winter Storm Warning is declared when “a considerable mix of dangerous winter weather is currently taking place or is about to occur.”