4 Ways That Heavy, Wet Snow Can Bring Hazards In A Winter Storm

Here Are 4 Dangers Of Heavy, Wet Snow

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Not all snow is created equally, and some types of snow are definitely more dangerous than others.

For example, heavy, wet snow is more than just a pain to shovel and dangerous to drive on – it can also be hazardous to your health and your home.

Early- and late-season winter storms – for example, those in November and March – can often come with snow that is much heavier and wetter than it typically would be in colder months like December, January and February.

(MORE: Winter Storm Central)

There is typically less cold air for a winter storm to work with early and late in the season, yielding surface temperatures closer to freezing or sometimes even above freezing as snow falls. This causes snowflakes to partially melt before reaching the ground, leading to heavier and wetter snow.

Heavy, wet snow has a low snow-to-liquid ratio – as low as 5-to-1, which means that for every 5 inches of snow, there is a 1-inch liquid equivalent.

Mid-winter snowstorms, on the other hand, with colder air in the 20s or even teens near the surface, may have a snow-to-liquid ratio of 10-to-1 to as high as 20-to-1, since melting isn't occurring before the snowflakes reach the ground.

Lake-effect snow is an example of a very dry snow, as it typically has snow-to-liquid ratios of 25-to-1 or 30-to-1, depending on how cold the air is that's flowing over the lake.

(MORE: Snow Ratios: An Important Role in Snowfall Forecasting)

The higher the snow-to-liquid ratio, the lighter and fluffier the snow, making it much easier to shovel and less hazardous, relative to heavy, wet snow.

Here’s why people have to be especially cautious and aware of this type of snowfall:

1. 'Heart-Attack Snow'

Heavy, wet snow is sometimes called "heart-attack snow" because shoveling it can trigger heart attacks in individuals with heart problems.

According to a Canadian study that looked at the number of heart attacks reported in Quebec hospitals between 1981 and 2013, one-third of the 128,000 heart attacks happened after a substantial snowfall.

A separate study from the Center for Injury Research and Policy noted that in the United States, an average of 100 cardiac deaths resulting from snow shoveling happened every year between 1990 and 2006.

The study found that patients over 55 years old were more than four times more likely than younger patients to experience cardiac-related symptoms while shoveling snow, and male patients within that age group were twice as likely to exhibit symptoms as female patients.

Therefore, if you can avoid doing so, don't shovel heavy, wet snow if you think you may be at risk of a heart attack. Hire someone to clear your driveway and sidewalk for you, or ask if a healthy family member would be willing to do you a favor.

2. Power Outages

Any trees or tree branches that break from the weight of the snow have the potential to fall onto power lines, potentially leaving you without power in a critical scenario.

Being without power during a snowstorm can be extremely dangerous, especially if you need electricity to heat your home. Losing heat in a snowstorm can cause pipes to freeze and potentially burst, which can lead to thousands of dollars in damage.

More importantly, prolonged exposure to extreme cold without any source of heat can be dangerous.

“If the cold persists and your heat is not restored, call family, neighbors, or friends to see if you can stay with them,” advises a New York City Emergency Management webpage on winter weather safety.

Falling trees and tree limbs can also land on homes or businesses and potentially cause damage to roofs in addition to the direct threat to roofs from heavy snow.

3. Roof Damage

Heavy snow can damage more than just trees and power lines – it can also cause roofs to be damaged or even cave in.

Most roofs should be able to support 20 pounds per square foot of snow before they become stressed, according to the Insurance Institute for Business & Home Safety (IBHS).

However, in parts of New England and mountainous areas throughout the U.S., snow loads may be higher and roofs may be able to support a greater amount of snow.

Using a snow-to-liquid ratio of 10-to-1, 10 inches of snow is equal to 1 inch of water, or about 5 pounds per square foot of roof space. This means you could have up to 4 feet of new snow before your roof will become stressed, the IBHS added.

But with heavier, more dense snow, that ratio can be much lower.

If the ratio is closer to 5-to-1, for example, 1 inch of water may be equivalent to 5 inches of snow, which means that your roof can reach the danger zone if total snow accumulation passes 2 feet. You may think your roof can hold more snow than it actually can, so keeping it clear is important.

Of course, only shovel your roof if you can do so safely. Hire a professional if you are unable to do it on your own.

4. Dangerous Travel Conditions

This should go without saying, but any accumulating snow can lead to dangerous travel conditions due to slippery roads for vehicles and slick runways for airplanes.

(MORE: The Dangers of Light Snow)

It's best to stay home until the snow stops and road crews have a chance to plow or salt the roads. If you must travel, drive slowly and give yourself plenty of extra time.

Also make sure you clear the roof of your car before you start driving. When snow is wet and compact, it can be more likely to fly off as one big clump, which can leave a hazard on the road or even hit someone’s windshield.

But there is one good thing about heavy, wet snow: It's great for building snowmen or having a serious snowball fight. Perhaps that'll keep your kids occupied while you do the dirty work of shoveling.