THUNDERSTORMSPHYSICS CCE

-Anushree K7’A’

CONTENTS

Introduction to Thunderstorms:1. What are thunderstorms?2. How they occur?3. Different types of thunderstorms4. Safety precautions

Examples of thunderstorms:1. 2010 Eastern Indian States2. 1939 South California tropical storm

WHAT ARE THUNDERSTORMS?

A thunderstorm is also known as an electrical storm, a lightening storm, thundershower or simply a storm. Thunderstorms are usually accompanied by strong winds, heavy rain and sometimes  snow, sleet, hail or no precipitation at all.

Thunderstorms result from the rapid upward movement of warm, moist air. They can occur inside warm, moist air masses and at fronts.

As the warm, moist air moves upward, it cools, condenses, and forms cumulonimbus clouds that can reach heights of over 20 km. As the rising air reaches its dew point, water droplets and ice form and begin falling the long distance through the clouds towards the Earth's surface.

As the droplets fall, they collide with other droplets and become larger. The falling droplets create a downdraft of air that spreads out at the Earth's surface and causes strong winds associated commonly with thunderstorms.

How do they occur?

Different types of thunderstorms

There are four types of thunderstorms:1. Single-cell2. Multicell cluster3. Multicell lines4.  Supercells.

Supercell thunderstorms are the strongest and the most associated with severe weather phenomena. Dry thunderstorms, with no precipitation, can cause the outbreak of wildfires with the heat generated from the cloud-to-ground lightning that accompanies them.

Preparedness

People should know the names of local counties, cities, and towns, as these are how warnings are described.

Monitor forecasts and know whether thunderstorms are likely in the area.

Be alert for natural signs of an approaching storm.

Cancel or reschedule outdoor events (to avoid being caught outdoors when a storm hits).

Avoid open areas like hilltops, fields, and beaches.

Safety

Take action immediately upon hearing thunder. Anyone close enough to the storm to hear thunder can be struck by lightning.

Avoid electrical appliances, including corded telephones. Cordless and wireless telephones are safe to use during a thunderstorm.

Close and stay away from windows and doors, as glass can become a serious hazard in high wind.

Do not bathe or shower, as plumbing conducts electricity.

Safety precautions

2010 Eastern Indian States

At approximately 11 pm local time, April 13, 2010, a severe storm struck parts of Bangladesh and eastern India. It lasted about 90 minutes, with the most intense portion spanning 30–40 minutes.

2010 Eastern India States. As of April 16, more than 140 deaths have been reported. At least

91 people died in the Indian state of Bihar, 44 in West Bengal and 4 in Assam.

 In Bangladesh, five deaths and 200 injuries were reported. Most of the deaths were women and children crushed when their huts were destroyed. Over 91,000 dwellings were destroyed in India and several thousand in Bangladesh; approximately 300,000 dwellings were at least partially damaged.

 Nearly 500,000 people were left homeless or otherwise affected by the storm. Rescue efforts have been inhibited as many roads, were blocked by downed trees and telephone poles. 

Medical personnel and supplies were quickly rushed to the affected areas, and aid packages were announced. Aid workers began to distribute rice, dried fruits, water, and temporary tarpaulin shelters on April 15.

1939 California tropical storm

The 1939 California tropical storm, also called the 1939 Long Beach tropical storm, El Cordonazo, The Lash of St. Francis was a tropical cyclone that hit Southern California in September, 1939.

1939 CALIFORNIA TROPICAL STORM. Formerly a hurricane, it was the only tropical storm to

make landfall in California in the twentieth century.The storm caused heavy rain in most parts of the country

and also lead to floods. The flooding killed 45 in Southern California, although some of these may be attributable to the rain immediately before the tropical storm. At sea, 48 were killed.

The tropical storm was credited with at least one beneficial effect: it ended a vicious heat wave that had lasted for over a week and killed at least ninety people.

 Out at sea, the Coast Guard and Navy conducted rescue operations, saving dozens of people. Schools were closed there as the wind had reached a mighty speed too.

People were advised not to use electrical appliances, not to stay near water outside and to stay away from any glass item.

PICTURES OF THE THUNDERSTORMS

2010 Eastern Indian States 1939 California tropical storm

SOURCE

Information: WikipediaPictures : Google images