Brookings effect

The Brookings effect, also known as the Chetco effect, is a weather pattern that occasionally occurs along the southern Oregon Coast in the United States. It is named after Brookings, Oregon, a city just a few miles north of the California border.

Partially as a result of this phenomenon, Brookings recorded its highest temperature ever, 110 degrees Fahrenheit, on July 8, 2008.

The Brookings effect is the same meteorological phenomenon as the Chinook wind, in which adiabatic heating increases the temperature of a mass of air as it travels down-slope.

The Brookings effect is most common in late fall and winter. During periods of dry weather, a high-pressure ridge sometimes forms over the Pacific Northwest or the Great Basin. Along the Oregon coast, and especially near Brookings, this often leads to an offshore wind or east wind. When the dry, cool air of the interior approaches the coast, it descends along the slopes of the coastal mountains, and is funneled down the Chetco River valley. By the time it reaches the coastal towns of Brookings and Harbor, which are separated by the Chetco River, the air is likely to be much warmer and drier. Even in mid-winter, temperatures of 20C (68F) or higher are very possible during such a pattern. During autumn the temperatures may soar to 25-30C (77-86F), sometimes even higher. Temperatures of 105F (41C) have been recorded.

The Brookings effect is likely caused by downsloping winds in the coastal mountains,...
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