65 Ice Storms-Mid

Ice Storms FOCUS Question How do ice storms form?

冰暴焦点问题冰暴是如何形成的?

Nature's Icing In some parts of the world, winter weather can create a frozen wonderland of snow and ice. Ponds freeze into solid sheets that support huts for ice fishing. Snow on hills is perfect for sledding. Snow and ice can be fun But they can also be dangerous. Snowy roads can make driving unsafe. Heavy ice can weigh down and snap tree branches and power lines. Many types of winter storms can cover the ground with white snow. An ice storm quickly coats an area in ice. Let's explore how ice storms are different from other winter storms.

大自然的结冰在世界上的一些地方，冬天的天气会创造出一个冰雪仙境。 池塘结冰成坚固的薄片，支撑着冰钓的小屋。 山上的雪最适合滑雪橇了。 雪和冰很有趣，但也很危险。 积雪路面会使驾驶变得不安全。 厚重的冰会压垮树枝和电线。 许多类型的冬季风暴可以用白雪覆盖地面。 一场冰暴很快就把一个地区覆盖上了冰。 让我们来探索一下冰暴与其他冬季风暴的不同之处。

How Winter Storms Form Winter storms form when cold and warm air masses bump into each other. In North America, cold dry air from Canada swoops south. Warm, moist air from Mexico moves north. Depending on how they meet, they create a cold or warm front. A cold front forms when cold air pushes into warm air. The warm, moist air rises higher into the sky. Water vapor in the warm air cools and turns into liquid water. Then clouds form Rain falls and thunderstorms may begin.

当冷热气团相互碰撞时，冬季风暴就形成了。 在北美，来自加拿大的干冷空气向南俯冲。 温暖潮湿的空气从墨西哥向北移动。 根据它们相遇的方式，它们会形成冷锋或暖锋。 冷锋是冷空气推进暖空气形成的。 温暖潮湿的空气升得更高。 暖空气中的水蒸气冷却后变成液态水。 然后云形成，下雨，雷暴可能开始。

Warm fronts are more likely to cause big winter storms. That may sound strange, but it's true. During a warm front, warm air moves into an area of cold air. The warm air rises up and flows over the top of the cold air mass. As the warm air rises, it gets colder. The water vapor turns into liquid water or ice. Now clouds form above the cold air. Precipitation, such as rain or snow, falls through the cold air mass instead of in front of it. The type of precipitation that falls depends on the temperature of the air it falls through.

暖锋更有可能导致冬季大风暴。 这听起来可能很奇怪，但这是真的。 在暖锋期间，暖空气进入冷空气区域。 暖空气上升并流过冷空气团的顶部。 随着暖空气的上升，天气变得更冷。 水蒸气变成液态水或冰。 现在云在冷空气上方形成。 降水，如雨或雪，通过冷空气团而不是在冷空气团前面落下。 降水的类型取决于它所经过的空气的温度。

Types of Precipitation Rain often begins as snow falling from clouds above a warm air mass. The snow melts as it passes through warm air. Rain hits the ground. Freezing rain falls when raindrops pass through very cold air. The raindrops become supercooled. They are below the freezing point of 0°C (32°F), but they remain liquid. The drops instantly freeze when they hit ice-cold surfaces. Sleet forms when rain passes through a large area of cold air. The raindrops freeze before landing on the ground as solid bits of ice. Snow falls when snowflakes stay frozen in cold air all the way to the ground.

降水的类型雨通常以雪从暖气团上方的云层中落下开始。 雪经过暖空气时会融化。 雨水打在地上。当雨滴穿过非常寒冷的空气时，就会出现冻雨。 雨滴变得过冷。 它们低于0°C(32°F)的冰点，但仍保持液态。 当水滴碰到冰冷的表面时，会立即冻结。 雨夹雪是雨水经过大面积冷空气时形成的。 雨滴在落到地面之前会凝固成固态的冰块。 当雪花在冷空气中一直冻结到地面时，就会下雪。

Frozen Can you guess which type of precipitation falls during an ice storm? Freezing rain falls during an ice. storm and covers every outdoor surface with ice The supercooled raindrops turn to ice as soon as they hit anything below freezing. One drop lands on a tree branch. Ping! It's ice! Another hits a mailbox. Ping More ice forms. A winter storm becomes an ice storm once surfaces are coated with at least 6.6 millimeters (0.25 in.) of ice. Wowser! Ice is heavy Just 12.7 millimeters (0.5 in.) of ice on a power line adds 227 kilograms (500 lb.) of extra weight.

你能猜到在冰暴期间会有哪种类型的降水吗? 冰天期间下着冻雨。 过冷的雨滴一旦碰到冰点以下的物体就会变成冰。 一滴落在树枝上。 萍!这是冰!另一个撞到了邮箱。 更多的冰形成。一旦表面覆盖了至少6.6毫米(0.25英寸)的冰，冬季风暴就会变成冰暴。 老古板!电线上只要有12.7毫米(0.5英寸)的冰，就会增加227公斤(500磅)的额外重量。