61 Hailstorms-Mid

Hailstorms FOCUS Question What causes hailstorms?

冰雹焦点问题冰雹是由什么引起的?

What Is Hail? You're walking home on a hot summer day when suddenly the sky becomes dark. A loud BOOM of thunder startles you. Then countless balls of ice start falling from the sky. Ice on a hot summer day? You bet—it's a hailstorm! Hail is a form of frozen precipitation— water that falls from the sky to the ground. It is made up of balls, or pellets, of ice. A single piece of hail is called a hailstone. Hailstones are usually about the size of a pea, but they can be as large as a grapefruit.

冰雹是什么?在一个炎热的夏日，你正走在回家的路上，突然天变黑了。 一声巨响把你吓了一跳。 接着，无数的冰球开始从天而降。 在炎热的夏天结冰?你说对了——是冰雹!冰雹是冰冻降水的一种形式——水从天空落到地面。 它是由冰球或冰球组成的。 一块冰雹叫做冰雹石。 冰雹通常只有豌豆大小，但也有葡萄柚那么大。

The Ups and Downs of Hail In the United States, the only cold thing people usually think about in summer is ice cream. While sleet and snow fall in winter, hail normally falls in summer from a type of cloud called cumulonimbus (KYOOM-yuh-low NIM-bus). These clouds produce thunderstorms. Thunderstorms have just the right conditions for making hail. They have updrafts—air that flows upward at high speeds—and supercooled water droplets. These tiny raindrops are below the freezing point but have not yet frozen solid. Strong updrafts catch the supercooled droplets, hurling them high up in the cloud. Here, cold air freezes them, either alone or around tiny ice crystals that form the center of hailstones. Once they get heavy enough, the hailstones start to fall.

在美国，人们在夏天唯一想到的冷的东西就是冰淇淋。 当雨夹雪在冬季降临时，冰雹通常在夏季从一种叫做积雨云的云(KYOOM-yuh-low NIM-bus)中降临。 这些云产生雷暴。 雷暴刚好有产生冰雹的条件。 它们有上升气流(高速向上流动的空气)和过冷的水滴。 这些微小的雨滴低于冰点，但还没有冻成固体。 强烈的上升气流抓住过冷的液滴，将它们抛向云中。 在这里，冷空气将它们单独或围绕在形成冰雹中心的小冰晶周围冻结。 一旦它们变得足够重，冰雹就开始降落。

While falling through the air, small hailstones may get caught in updrafts and pulled higher again. More supercooled water freezes around them and they grow. The hailstones grow larger and larger as they gain more layers through a process called accretion. Updrafts can force hailstones upward over and over; the hailstones grow by accretion and then fall. The more often the cycle repeats, the larger the hailstones grow. This cycle continues until the hailstones get too heavy and fall all the way to the ground. Strong storms have powerful updrafts that can make very large hailstones before they fall to the ground.

在空中下落时，小冰雹可能会被上升气流困住，再次被拉得更高。 更多的过冷水在它们周围结冰，它们就变大了。 随着冰雹通过一个叫做吸积的过程获得更多的层，它们变得越来越大。 上升气流可以迫使冰雹一次又一次地上升;冰雹通过吸积而增长，然后下降。 这种循环重复得越频繁，冰雹就越大。 这种循环会一直持续下去，直到冰雹变得太重，一直落到地面上。 强风暴有强大的上升气流，在落到地面之前可以形成非常大的冰雹。

Look Out Below! Some people refer to hail as "the white plague" because hail can cause millions of dollars in damage! Rock-hard hailstones can cause serious damage to crops, cars, buildings, and aircraft. Even small hailstones can crush plants, dent cars, break windows, and harm animals. Although it is rare, people and other animals can die from hail. Hailstorms can occur anywhere thunderstorms happen. In the United States, hail most often occurs in the Great Plains states in the middle of the country. This area is known as Hail Alley. Wowser! Hailstones hurtle toward the ground at speeds up to 145 kilometers (90 mi.) per hour!

往下看!有些人把冰雹称为“白色瘟疫”，因为冰雹可以造成数百万美元的损失!岩石般坚硬的冰雹会对农作物、汽车、建筑物和飞机造成严重破坏。 即使是很小的冰雹也能压碎植物、撞凹汽车、打破窗户、伤害动物。 虽然这种情况很罕见，但人类和其他动物也会死于冰雹。 冰雹可能发生在雷暴发生的任何地方。 在美国，冰雹最常发生在美国中部的大平原各州。 这个地区被称为冰雹巷。 老古板!冰雹以每小时145公里(90英里)的速度冲向地面!

Hail Events On July 23, 2010, a terrible thunderstorm hit Vivian, South Dakota. Afterward, a man named Les Scott spotted something amazing. It was a huge hailstone about the size of a volleyball! His find broke the record for the largest and heaviest hailstone in the United States. The deadliest hailstorm happened in India on April 30, 1888. The storm killed at least 246 people in an area outside Delhi. RECORD-BREAKING HAILSTONES IN THE UNITED STATES Measurement Data Date Location largest (circumference) 47.6 cm (18.75 in.) June 22, 2003 Aurora, Nebraska largest (diameter) 20.3 cm (8 in.) July 23, 2010 Vivian, South Dakota heaviest 0.88 kg (1.94 lb.) July 23, 2010 Vivian, South Dakota

2010年7月23日，一场可怕的雷暴袭击了南达科他州的维维安。 后来，一个名叫莱斯·斯科特的人发现了一些惊人的东西。 那是一颗排球大小的巨大冰雹!他的发现打破了美国最大、最重冰雹的记录。 最致命的冰雹发生在1888年4月30日的印度。 这场风暴在德里郊外造成至少246人死亡。 美国破纪录的冰雹测量数据日期地点最大(周长)47.6厘米(18.75英寸)2003年6月22日极光，内布拉斯加州最大(直径)20.3厘米(8英寸)2010年7月23日，Vivian, South Dakota最重0.88 kg(1.94磅)