Any energetic extratropical cyclone that sweeps the eastern seaboard of North America in winter.

• A. Storm
• B. Polar Cell
• C. Precipitation
• D. Nor'easter

Answer: (D)

The key idea is the specific wintertime storm that travels along the U.S. East Coast and brings strong northeast winds. A nor’easter is an energetic extratropical cyclone that forms near the coast and tracks northeast along the coast, pulling in cold air from the land and warm, moist air from the Atlantic. Because the winds wrap around the low-pressure center toward the northeast, coastal areas experience powerful northeast winds and heavy precipitation, often with snow inland and rain along the shore. This combination of coastal trajectory in winter and strong northeast winds is what defines a nor’easter. A generic storm lacks the regional, winter-coastal context; a polar cell is a large-scale atmospheric circulation pattern, not a weather event; and precipitation describes the rain or snow itself, not the storm system producing it.