Tornado Alley in the context of "Wyoming"

The Gulf of Mexico (Spanish: Golfo de México) is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southwest and south by the Mexican states of Tamaulipas, Veracruz, Tabasco, Campeche, Yucatán, and Quintana Roo; and on the southeast by Cuba.

The Gulf of Mexico basin is roughly oval and is about 810 nautical miles (1,500 kilometres; 930 miles) wide. Its floor consists of sedimentary rocks and recent sediments. It is connected to part of the Atlantic Ocean through the Straits of Florida between the U.S. and Cuba, and with the Caribbean Sea via the Yucatán Channel between Mexico and Cuba. Because of its narrow connection to the Atlantic Ocean, the gulf has very small tidal ranges.Moisture from the Gulf of Mexico also contributes to weather across the United States, including severe weather in Tornado Alley.

A supercell is a thunderstorm characterized by the presence of a mesocyclone, a deep, persistently rotating updraft. Due to this, these storms are sometimes referred to as rotating thunderstorms. Of the four main classifications of thunderstorms—supercell, squall line, multi-cell, and single-cell—supercells are the least common overall and have the potential to be the most severe. Supercells are often isolated from other thunderstorms, and can dominate the local weather up to 32 kilometres (20 mi) away. They tend to last 2–4 hours, but under highly favorable conditions, can last even longer.

Supercells are often put into three classification types: "classic" (normal precipitation level), low-precipitation (LP), and high-precipitation (HP). Low-precipitation supercells are usually found in climates that are more arid, such as the high plains of the United States, and high-precipitation supercells are most often found in moist climates. Supercells can occur anywhere in the world under the right pre-existing weather conditions, but they are most common in the Great Plains of the United States in an area known as Tornado Alley. A high number of supercells are seen in many parts of Europe as well as in the Tornado Corridor of Argentina, Uruguay, southern Brazil, and Paraguay.