Chapter 14 - Thunderstorms

Question 1

What is a thunderstorm?

Answer 1

Convective storms that form with rising air.

Question 2

What atmospheric conditions are necessary for the development of ordinary cell (air mass) thunderstorms=

Answer 2

Typically involves warm, moist air rising in a conditionally unstable environment.

Question 3

How do downdrafts form in ordinary cell thunderstorms?

Answer 3

Dry air around cloud gets drawn in (entrainment) and evaporates the water. Then the air becomes colder because the lost of latent heat. Becomes heavier than the air around it and sinks.

Question 4

Why do ordinary cell thunderstorms most frequently form in the afternoon?

Answer 4

The atmosphere is most unstable in the afternoon.

Question 5

Describe one process by which thunderstorms become electrified.

Answer 5

graupel (hailstones) collide with supercooled water droplets. They freeze and release latent heat. Surface of hailstone becomes warm. When in contact with colder ice crystals, there is a net transfer of positive ions from warmer object to colder object. Hail negative and ice positive. LIGHTNING :O

Question 6

Sinking air warms, yet the downdrafts in a thunderstorm are usually cold, why?

Answer 6

Entrainment of dry air, which cools the descending air by the evaporation of rain droplets, results in cooler air than would occur if the temperature in the downdraft were determined by the environmental or dry adiabatic lapse rates.