Derechos, Haboobs, Gustnadoes, and Bombogenesis… What the Heck Are They?

Whether you’ve heard of them or not, the above are real terms used by The National Weather Service to describe specific weather-related conditions. Let’s look at what they are:

Derechos: These are widespread, long-lived windstorms associated with bands of rapidly moving showers or thunderstorms known as bow echoes, squall lines, or quasi-linear convection systems. These strong storms are capable of producing destruction like a hurricane or tornado, but the damage occurs in one direction along a relatively straight path. In fact, one of the meanings of the word “derecho” in Spanish is “straight.” Per weather.gov, these storms most commonly occur in the US along the “Corn Belt” from the upper Mississippi Valley southeast into the Ohio Valley and from the southern Plains northeast into the mid-Mississippi Valley. 70% of all Derechos occur between May to August, during the warm season. 

Haboobs: These are intense dust storms carried on an atmospheric gravity current known as a weather front. Haboobs typically occur in dry land area regions throughout the world. They normally occur in Arizona, New Mexico, and even parts of eastern California and West Texas in the US. The word “haboob” is Arabic for the word “blown.” Haboobs are large walls of dust created from high winds that rush out of a collapsing thunderstorm. Per Arizona’s ABC 15, “Cold air in front of the storm rushes down at an incredible rate, picking up massive amounts of dust and sand and blowing them in the air.” They explain that as a storm builds, it can completely block out the sun, making it nearly impossible to see just a few feet in front of you. The wall of dust typically reaches from 1,500 feet to 3,000 feet and can stretch as far as 100 miles wide. Effects can be dangerous and linger to negatively affect air quality and make breathing difficult.

Gustnadoes: This is the term for a strong whirlwind at the leading edge of a storm front or squall line. It is a brief, shallow surface-based vortex which forms within the downburst emanating from a thunderstorm. They can occur anywhere in the US because of a thunderstorm. Speculation exists that a gustnado was responsible for the storm that killed seven during the collapse of the stage at the Indiana State Fair in 2011. A gustnado is structurally different than a tornado. Tornadoes are associated with warm and powerful updrafts which feed the cloud. Tornadoes form from and are connected to the Cumulonimbus cloud base, and it is driven by the mesocyclonic rotation of the cloud. Unlike tornadoes, gustnadoes are not connected to the cloud base. Gustnadoes form due to non-tornadic straight-line wind and are associated with cool downdrafts. However, these thunderstorm wind events are serious as they may cause damage akin to that of a tornado.

Bombogenesis: This is the process by which a midlatitude cyclone intensifies in a rapid amount of time. It starts with a process called cyclogenesis, which happens when an area of low pressure develops or strengthens. Typically, a clash of hot and cold air masses happens over milder ocean waters and supplies fuel for the storm. A millibar measures atmospheric pressure. Per Storm Guard Roofing and Construction, “In Bombogenesis, a storm’s barometric pressure plummets by at least 24 millibars in 24 hours, which causes strong winds and a rapidly intensifying storm.” Extreme cases are termed “explosive cyclogenesis” by meteorologists. Bombogenesis creates bomb cyclones, which are common in the Pacific Ocean and can also occur in the Atlantic. Winter bomb cyclones can hit the east coast and deliver intense snow and high winds, thus creating a big storm.

The above terms are actual words used by meteorologists to describe specific storms. Understand that each can lead to dangerous weather conditions. Thus, if you hear any of them being used to describe weather headed your way, heed your meteorologist’s advice for safety.