Weather Wednesday: types of circulations

Weather Wednesday: types of circulations

(KWES) - West Texas often experiences different types of weather. Sometimes storms across the area can spin up different types of circulations such as tornadoes, landspouts and gustnadoes. There are varying differences in each type of circulation, intensity and how each form.  

Landspout: A landspout forms when air starts to spin along the surface due to wind shear. Wind shear occurs by the wind changing direction or speed with height.  As a developing thunderstorm moves over the spinning air; the storm will stretch the air upwards and a landspout can form.   

Landspouts often appear narrow, tubed, or have a rope-like shape while the storm is forming with a non-rotating cloud base. Most landspouts tend to be weak (around 60 mph) and short-lived, however, a few can be strong enough to produce damage of at a least an EF-2 tornado (110-137 mph) or less.

Gustnado: Gustnadoes are a type of non-tornado.  Gustnadoes are caused by the downward motion of air coming out of a thunderstorm. As this downward wind hits the surface ahead of a storm, whirls of dust or debris can form. Some gustnadoes could become strong enough to cause damage.

Tornado: A tornado starts to form as a column of air starts to rotate from wind shear at two different levels above the ground. This shear creates a horizontal tube of rotating air. (This is much like a pencil or pen rolling across a flat surface). The rising air within the thunderstorm can tilt this rotating air upright into the storm. This upward rotation can go through much of the storm and can cause the cloud to rotate. As more warm and moist air lifts into the storm, a lowering or wall cloud can form beneath the the storm. This wall cloud is often the place where a tornado is likely to form. This type of tornado formation is often the most common and dangerous.  

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