9781422275870

Ultimate Danger Ultimate Danger Ultimate

Chapter 1

Dangerous Blizzards and Ice Storms P eople use the word blizzard casually all the time, but it actually has a specific definition: a snowstorm with wind speeds of at least 35 miles per hour (56 kilometers per hour) for a minimum of three hours. A severe blizzard is a storm with winds in excess of 45 mph (72 kmh) and temperatures that drop below 10°F (−23°C). Blizzard-force winds can also rip trees from their roots, snap powerlines, and whip up waves that flood coastal communities. Blizzard snow can come down at such a furious rate that it can bury communities under huge drifts in almost no time at all. In addition, temperatures can dip way below zero, causing frostbite and hypothermia for those unlucky enough to be caught outside. Blizzards occur when currents of warm, moisture-laden air smack into a wall of cold, dry air. When that happens, cool air falls toward the earth, creating massive changes in air pressure. This difference spurs powerful winds that can push falling snow sideways and create a dangerous wind chill that can drop the air temperature by some 30 degrees.

Dangerous Blizzards and Ice Storms

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