A northerly wind; in general, a cold windstorm from the north.
The term has several specific applications: 1) In the southern United States, especially in Texas (Texas norther), in the Gulf of Mexico, in the Gulf of Panama away from the coast, and in Central America (norte), the norther is a strong cold wind from between northeast and northwest. It occurs between November and April, freshening during the afternoon and decreasing at night. It is a cold air outbreak associated with the southward movement of a cold anticyclone. It is usually preceded by a warm and cloudy or rainy spell with southerly winds. The norther comes as a rushing blast and brings a sudden drop of temperature of as much as 25°F in one hour or 50°F in three hours in winter. 2) The California norther is a strong, very dry, dusty, northerly wind that blows in late spring, summer, and early fall in the valley of California or on the West Coast when pressure is high over the mountains to the north. It lasts from one to four days. The dryness is due to adiabatic warming during descent. In summer it is very hot. 3) The Portuguese norther is the beginning of the trade wind west of Portugal. 4) Norther is used for a strong north wind on the coast of Chile that blows occasionally in summer. 5) In southeast Australia, a hot dry wind from the desert is called a norther.