Lesson 20: Stage 2 Exam Revision

What is the major motivating force behind atmospheric circulation?

• Rotation of the earth.

• High and low pressure belts.

• Uneven heating of the earth's surface.

What processes result in moisture being added to unsaturated air?

• Evaporation and Sublimation.

• Condensation and Sublimation.

• Condensation and latent heat or vaporization.

What weather conditions can you expect with a small or converging temperature/dewpoint spread?

• Fog or low clouds.

• Strong surface winds.

• Low visibility and gusty winds.

With the approach and passage of a frontal system in the United States, what pressure and wind direction changes take place?

• The pressure falls as the front approaches and rises after its passage, while the wind direction shifts to the left after frontal passage.

• The pressure rises as the front approaches and falls after its passage, while the wind direction shirts to the left after frontal passage.

• The pressure falls as the front approaches and rises after its passage, while the wind direction shifts to the right after frontal passage.

What conditions are necessary for the formation of thunderstorms?

• Unstable air, a lifting force, and high moisture levels.

• High wind velocities aloft and a small temperature/dewpoint spread.

• The close proximity of a high pressure system to a steep pressure gradient.

Thunderstorms and squall lines are generally associated with what type of front?

• Stationary.

• Slow-moving cold front.

• Fast-moving cold front.

Select the true statement regarding wind shear.

• Wind shear is a sudden, drastic shift in wind speed that occurs in a horizontal plane below 1,000 feet AGL.

• A wind shear alert is usually issued if a reading from a LLWAS sensor differs from the mean by 5 knots.

• A microburst, one of the most dangerous sources of wind shear, is a downdraft associated with convective activity.

The elevation at Denver (KDEN) is 5,400 feet. According to the accompanying aviation routine weather report (METAR), how far below the ceiling will you be if you are flying at 7,500 feet MSL over Denver?

METAR KDEN 081055Z 21010G27KT 4DM -RA BR SCT015 BKN030 20/16 A2989

• 900 feet.

• 2,100 feet.

• 8.400 feet.

According to the accompanying terminal aerodrome forecast (TAF), by 0500Z the visibility and ceiling at Philadelphia (KPHL are expected to be

• Six miles and 2,000 broken.

• Four miles and 4,000 overcast.

• Greater than six miles and a few clouds at 2,000 feet.

Use the above winds and temperatures aloft forecast to determine the wind direction, velocity and air temperature expected at 9,000 feet MSL over Glasgow (GGW).

• 310° true at 11 knots; -8°C

• 311° true at 10 knots; 8°C

• 310° magnetic at 11 knots; -8°F