Question 823Navigation General

The correct answer is B) A pumping of the barometer up and down a few millibars. This is because a pumping or fluctuating barometer is a clear indicator that a tropical cyclone may be within 500 to 1,000 miles of your position. As a tropical cyclone approaches, the central low pressure area causes the barometer to rise and fall in an irregular pattern, typically by a few millibars. This is a characteristic sign that the system is approaching, even before other obvious weather changes are observed. The other answer choices, while potentially associated with approaching tropical systems, are not as definitive or reliable as the barometric fluctuations. For example, wind shifts, swell changes, and increasing cloud cover can have other causes besides an impending tropical cyclone.