Thunderstorms & Lightning

What type of cloud is primarily associated with thunderstorms?

Cumulonimbus

Which of the following is not an ingredient required for thunderstorm formation?

C) A cold air mass

Which is not a lifting mechanism that helps form thunderstorms?

B) Conduction

Thunderstorms are most commonly associated with which air mass in the U.S.?

C) mT

What mechanism causes more thunderstorms near the western boundary currents (WBC)?

C) Warm water

What type of thunderstorm is isolated, short-lived, and often triggered by convection?

C) Air mass (single-cell)

What stage of an air mass thunderstorm is dominated by updrafts?

C) Cumulus

During which stage of an air mass thunderstorm do downdrafts dominate?

C) Dissipating

What type of thunderstorm forms a long line along or ahead of cold fronts?

B) Squall line

Which of the following defines a severe thunderstorm?

B) Winds > 50 knots or hail ≥ 1 inch or a tornado

What percentage of U.S. thunderstorms are classified as supercells?

B) 2–3%

What is the rotating updraft in a supercell called?

C) Mesocyclone

Supercells are often how tall?

C) Up to 65,000 ft

Mesoscale Convective Complexes (MCCs) typically begin as:

A) Isolated storms

MCCs are hazardous mainly because they:

C) Are slow-moving and cause flooding

What are warm, moist, rising air currents in a thunderstorm called?

B) Updrafts

What happens when a thunderstorm updraft breaks through the tropopause?

C) Overshooting top develops

What is formed by a cold downdraft hitting the surface and pushing warm air?

B) Gust front

Which feature appears at the top of a thunderstorm and is pushed by upper-level winds?

B) Anvil

What is often triggered by gust fronts and can enhance thunderstorm activity?

C) New cell formation

What percent of lightning occurs between clouds (cloud-cloud)?

D) 80%

The basic cause of lightning is:

B) Charge separation

Thunder is caused by:

B) Lightning heating air rapidly

The temperature of a lightning bolt can reach:

C) 20,000˚C

Which hazard is the number one thunderstorm killer?

C) Flash flooding

Hail formation requires:

C) Strong vertical winds

Which wind event is very dangerous for aircraft due to sudden downward motion?

B) Microburst

A derecho is similar to a gust front but is:

C) Longer lasting and stronger

What results when ice particles repeatedly circulate within a thunderstorm?

A) Hail growth

Which feature helps initiate additional thunderstorm cells from cold air outflow?

B) Gust front