DWO Weather Assessment 3 — Questions and Answers
Question 1: A vessel is steaming in tropical waters and the watch officer notices a sudden drop in air temperature accompanied by a darkening sky to windward. This most likely signals:
- A passing warm front
- An approaching squall or thunderstorm (Correct answer)
- The onset of trade winds
- A tropical high pressure cell
Correct answer: An approaching squall or thunderstorm
A sudden temperature drop combined with darkening cumulonimbus clouds to windward is a classic warning sign of an imminent squall or thunderstorm.
Question 2: What does the term 'occluded front' mean in meteorological terms?
- A front that has stalled over water for more than 48 hours
- A front formed when a cold front overtakes a warm front (Correct answer)
- A front moving faster than 30 knots
- A stationary boundary between two equal air masses
Correct answer: A front formed when a cold front overtakes a warm front
An occluded front forms when a faster-moving cold front catches up to and lifts the warm front, cutting off the warm air from the surface.
Question 3: At Beaufort Force 8, a deck watch officer should expect approximate wind speeds of:
- 17-21 knots
- 28-33 knots
- 34-40 knots (Correct answer)
- 41-47 knots
Correct answer: 34-40 knots
Beaufort Force 8 (Fresh Gale) corresponds to wind speeds of 34-40 knots with high waves and blown spray.
Question 4: Which cloud type is most directly associated with thunderstorm development?
- Altostratus
- Cumulonimbus (Correct answer)
- Nimbostratus
- Stratocumulus
Correct answer: Cumulonimbus
Cumulonimbus clouds are the hallmark of thunderstorm activity, capable of producing lightning, hail, and severe gusts.
Question 5: On a NAVTEX weather broadcast, the term 'GALE WARNING' is issued when winds are forecast to reach:
- 22-27 knots
- 28-33 knots
- 34-47 knots (Correct answer)
- 48 knots or above
Correct answer: 34-47 knots
A Gale Warning is issued when sustained winds of 34 to 47 knots (Beaufort 8-9) are expected in the forecast area.
Question 6: When analyzing a surface weather chart, a trough of low pressure is represented by:
- Solid lines connecting points of equal temperature
- An elongated area of low pressure extending from a cyclone (Correct answer)
- Concentric closed isobars around a high pressure center
- Dashed lines showing wind shift boundaries
Correct answer: An elongated area of low pressure extending from a cyclone
A trough is an elongated region of relatively low atmospheric pressure, often associated with wind shifts and unsettled weather.
Question 7: A deck watch officer in the Northern Hemisphere observes the wind backing (shifting counterclockwise). This is commonly associated with:
- Improving weather behind a cold front
- Deteriorating weather as a warm front approaches (Correct answer)
- The passage of a high pressure center
- Subsiding air and clearing skies
Correct answer: Deteriorating weather as a warm front approaches
In the Northern Hemisphere, a backing wind often signals an approaching warm front and deteriorating weather conditions.
DWO Weather Assessment 3
A vessel is steaming in tropical waters and the watch officer notices a sudden drop in air temperature accompanied by a darkening sky to windward.
This most likely signals: