Understanding Blizzard Conditions and Characteristics

Michael Matthews from the Bismar Weather Education Center explains blizzards, focusing on their characteristics, formation, and the conditions required for their occurrence. A blizzard is defined by the National Weather Service as having winds of at least 35 mph and snow that reduces visibility to less than 1/4 mile for three or more hours. Blizzards can occur without new snowfall if there is enough wind and loose snow on the ground, known as ground blizzards. The condition of the snow pack significantly affects the likelihood of a ground blizzard, with fresh, uncompacted snow being most susceptible. The video concludes with a call to explore more educational resources.

What are the basic elements required for a blizzard?

• Wind and rain

• Wind and snow

• Cold temperatures and snow

• Snow and rain

According to the National Weather Service, what wind speed is required for a blizzard?

• 25 mph

• 30 mph

• 35 mph

• 40 mph

How long must blizzard conditions persist to be officially classified as a blizzard?

• 1 hour

• 2 hours

• 4 hours

• 3 hours

What is a 'whiteout' condition?

• When visibility is reduced to less than 1/4 mile

• When it is snowing heavily

• When the temperature drops below freezing

• When the sky is completely white

Can a blizzard occur without any snowfall?

• No, it must be snowing heavily

• No, snowfall is always required

• Yes, if the temperature is below freezing

• Yes, if there is enough wind and loose snow on the ground

What is a ground blizzard?

• A blizzard that occurs only at night

• A blizzard with clear skies but strong winds blowing loose snow

• A blizzard with heavy snowfall

• A blizzard that occurs in mountainous regions

What factor makes snow more resistant to being blown around?

• Fresh snowfall

• Snow that has settled and compacted

• High temperatures

• Heavy rainfall

What happens to the snowpack when temperatures rise above freezing and then fall back below freezing?

• An icy top layer forms

• It melts completely

• It becomes more compact

• It becomes loose and powdery

When are ground blizzards most common?

• In early spring

• In the dead of winter

• In late winter

• In early winter

What is the best condition for ground blizzards to form?

• Snow that is compacted and icy

• Snow that has melted and refrozen

• Snow that is loose and powdery

• Fresh snow that has settled and never melted