Thunderstorms Overview

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Questions and Answers

What characterizes the final stage of an ordinary thunderstorm?

The storm gains energy from downdrafts.

The updraft continues to supply energy.

The downdraft cuts off the updraft. (correct)

The storm forms through strong wind shear.

What is a distinguishing characteristic of a supercell thunderstorm?

There is no significant wind shear present.

It can spawn tornadoes under certain conditions. (correct)

Storms last for only a short duration.

It has a diameter of less than 1 km.

How does a multi-cell thunderstorm differ from an ordinary thunderstorm?

The downdraft forms directly above the updraft.

It can induce the formation of additional storms. (correct)

It has no wind shear present.

It is consistently smaller in diameter.

What hazard is associated with microbursts?

They produce localized downdrafts with strong wind shears. Signup and view all the answers

Which of the following is true about the downdraft in a supercell thunderstorm?

It maintains the updraft, allowing the storm to last for several hours. Signup and view all the answers

What is the characteristic wind direction of tornadoes as they typically rotate?

Counterclockwise Signup and view all the answers

What is the primary meteorological condition for the formation of tornadoes?

Supercell thunderstorms Signup and view all the answers

Which of the following is true about the funnel cloud preceding a tornado?

It is a precursor that has not yet touched the ground. Signup and view all the answers

What is a common characteristic of thunderstorms?

They are associated with strong gusts of wind and thunder. Signup and view all the answers

What does the Enhanced Fujita Scale primarily account for when classifying tornadoes?

Damage indicators and construction quality Signup and view all the answers

What are the stages of an ordinary thunderstorm?

Cumulus, Mature, Dissipating. Signup and view all the answers

Which condition is NOT necessary for tornado formation?

Strong ocean currents Signup and view all the answers

What are mesoscale convective complexes characterized by?

Oval or roughly circular systems containing several thunderstorms Signup and view all the answers

What role does latent heat play in the development of thunderstorms?

It condenses the water vapor and warms the air. Signup and view all the answers

Which wind speed category on the Fujita Scale indicates 'Incredible Damage'?

F5: 417 – 515 km/h Signup and view all the answers

What is a typical lifespan of an average squall line?

More than 10 hours Signup and view all the answers

How does lightning primarily form within a thunderstorm?

Through charge separation within the cloud Signup and view all the answers

What is one of the main limitations of the original Fujita Scale?

It is based on subjective visual assessments of damage. Signup and view all the answers

Which of the following categories of thunderstorms is characterized by significant vertical wind shear?

Supercell Thunderstorm Signup and view all the answers

What event is noted as an example of a severe squall line impact?

Huntsville Tornado Signup and view all the answers

What happens during the mature phase of an ordinary thunderstorm?

A downdraft with precipitation develops. Signup and view all the answers

What feature forms as the vortex tube in the atmosphere begins to rotate vertically?

Funnel cloud Signup and view all the answers

What triggers the formation of a gust front in a thunderstorm?

The downdraft air spreading across the surface. Signup and view all the answers

What temperature can air reach in a lightning strike?

30,000º C Signup and view all the answers

In the formation of lightning, which particles tend to rise to the top of the storm?

Smaller positive charge particles Signup and view all the answers

How do large thunderstorms potentially lead to the formation of tornadoes?

Through interactions between strong updrafts and downdrafts. Signup and view all the answers

What is a key feature of the main part of the lightning flash?

It involves a return stroke carrying charge back to the cloud Signup and view all the answers

Which condition is NOT a necessary factor for the development of a thunderstorm?

The elimination of all wind shear. Signup and view all the answers

What is a major characteristic of squall lines?

They advance at right angles to their line and can produce severe weather Signup and view all the answers

What is the primary reason hailstones form in cumulonimbus clouds?

Deposition of supercooled water onto an ice core Signup and view all the answers

Which region in the United States typically experiences the most hail days?

Leeward side of the Rockies Signup and view all the answers

What characteristic of hailstones contributes to their potential damage?

Their size and weight Signup and view all the answers

Which of the following best describes the process by which hailstones grow?

Recycling through up- and downdrafts Signup and view all the answers

What is the significance of the World Wide Lightning Location Network?

To provide real-time lightning information worldwide Signup and view all the answers

What phenomenon does the acronym ENSO represent in relation to thunderstorms?

El Niño Southern Oscillation Signup and view all the answers

During which time of day do thunderstorms typically peak in Florida?

Mid to late afternoon Signup and view all the answers

What is the largest hailstone recorded in Canada according to recent data?

292.71 grams and 123 mm in diameter Signup and view all the answers

How many cloud droplets are estimated to form a golf ball-sized piece of hail?

10 billion Signup and view all the answers

What characterizes the worldwide distribution of thunderstorms according to seasonal probability?

Higher in summer hemisphere and mainly over land Signup and view all the answers

Study Notes

Thunderstorms

Thunderstorms are violent storms that cause heavy precipitation, strong gusts of wind, and thunder and lightning.
Thunderstorms are also known as convective storms.
Surface heating causes thunderstorms to form.
Thunderstorms are characterized by cumulonimbus clouds.
As air rises in the cloud, it cools and some of its water vapor condenses.
The condensation releases latent heat, warming the surrounding air.
Ordinary, multi-cell, supercell, and mesoscale convective complexes (MCCs) are four categories of thunderstorms.
Ordinary thunderstorms often develop within large air masses and are not necessarily near a frontal system.
They have little vertical wind shear.
Ordinary thunderstorms have three stages:
- Developing
- Mature
- Dissipating
Multi-cell thunderstorms have moderate wind shear that tilts the storm, allowing the downdraft to form downwind of the updraft.
Supercell thunderstorms form with strong vertical wind shear and can spawn tornadoes.
Supercells can last for several hours.
Microbursts are localized downdrafts that can create strong wind shear when they reach the surface.
MCCs are multiple thunderstorms organized in a circular fashion.
Squall lines are a series of very vigorous cumulonimbus clouds that merge to form a continuous line and advance at right angles to the line itself.

Lightning

Lightning is an electrical discharge that neutralizes a charge separation that has accumulated within a cloud between two clouds, or between a cloud and the ground.
Most (90%) lightning starts at the cloud base and goes to the surface.
The first step of the process is the ionization of a path of about 50 m by 3 million volts of electricity.
The air heats to 30,000º C, generating a shock wave which is heard as thunder.
Lightning detection can be done by detecting radio waves (sferics) that are produced during lightning.

Hail

Hail is a precipitation in the form of hailstones, which are hard, more or less spherical pieces of ice.
Hail stones form in cumulonimbus clouds.
Golf ball-sized hail stones require 10 billion cloud droplets.
The leeward side of the Rockies has the most hail days in the United States.

Tornadoes

Tornadoes form when a rapidly rotating column of air reaches the ground.
Tornadoes are also known as funnels or twisters.
A funnel cloud is the precursor to a tornado.
Tornadoes are typically counterclockwise and 100–600 m in diameter.
Tornadoes are usually short-lived and can produce peak winds over 400 km/h.
Tornadoes are formed from supercell thunderstorms.
Wind shear causes the formation of the vortex tube.
In a supercell thunderstorm, the updraft causes the rotating column of air (vortex tube) to take on a vertical component.
When the vortex tube becomes vertical and reaches the ground, it becomes a tornado.

Tornado Classification

The Fujita Scale classifies tornadoes based on the damage they cause.
Developed in 1971 by Ted Fujita, the Fujita Scale uses a six-category system.
The Enhanced Fujita Scale (EF-scale) was created to address some of the limitations of the original Fujita Scale.
The EF-scale provides more accurate estimates of tornado wind speeds.

Thunderstorms and ENSO

ENSO is a climate pattern that refers to the El Niño and La Niña phases.
During El Niño, warmer-than-average sea surface temperatures are present in the central and eastern Pacific Ocean.
During La Niña, cooler-than-average sea surface temperatures occur in the central and eastern Pacific Ocean.

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Description

This quiz covers the formation and characteristics of thunderstorms, including the different types such as ordinary, multi-cell, supercell, and mesoscale convective complexes. It also explores the stages of ordinary thunderstorms and the role of surface heating and condensation in their development.