Bow echo

Bow echoes tend to develop when moderate to strong wind shear exists in the lower 2 to 3 km of the atmosphere.

The strength of the cold pool and mesohigh at the surface as well as warmer temperatures aloft due to convection works to create a mesolow at mid-levels which strengthens the jet.

[5] Due to the small size of the bow echo, the vortices help enhance the mid-level flow between them, which strengthens the rear inflow jet.

In a type of long-lived and powerful bow echo known as a derecho, wind speeds can reach up to or exceed 100 mph (160 km/h) and can produce a damage path extending for hundreds of miles.

The semiarid climate and rugged terrain in the interior west of the United States do not favour the development of bow echoes.

However, on 21 April 2011, a bow echo associated with a fast-moving mid-tropospheric perturbation formed across the Great Salt Lake (GSL) in Utah, producing damaging winds along its path.

[8][9] In the 2014 Pentecost weekend storms in Europe, a violent bow echo moved across the Rhine-Ruhr metropolitan region,[10] causing 6 fatalities and an estimated 650 million euros in damages.