-Non Supercell Tornadoes-

Gustnadoes

• A term meaning “gust front tornado”

• Short lived low level based vortices that form on the gust front, or under the shelf cloud.

• Rotation – Not just blowing dust

• Can cause damage

• Often form below radar beam

Decorative Image: Image of two gustnadoes.

Speaker Notes:

• By definition, a tornado is a violently rotating column of air from a thunderstorm in contact with the ground. Typically these tornadoes form with supercell thunderstorms that will be discussed later.

• Gustnadoes are short lived vortices that form under the leading edge of rain-cooled air ahead of the squall line called the ‘gust front’. The cloud that identifies this gust front is called a shelf cloud.

• Sometimes, as seen in the above image, a gustnado will form under the shelf cloud.

• NOTE: This is NOT a dust devil. Dust devils form usually where storms are absent. Gustnadoes form on the leading edge of the rain cooled air associated with storms and do rotate and do cause damage, however winds with gustnadoes are usually under 100 MPH.

• Because this process occurs at the ground, it falls below the beam of the radar, thus gustnadoes are usually not observed on radar.

• Most gustnadoes last only a couple of minutes.