Derecho

 

Derecho is derived from the Spanish for “straight”.

 

Features of the a derecho according to the United States National Weather Service (NWS):

(1) thunderstorm complex (line or band of thunderstorms)

(2) damaging winds with an extent >= 250 miles (>= 400 kilometers)

(3) wind gusts >= 58 miles per hour (>= 93 km/h, >= 50 knots)

(4) maintained for >= 6 hours

 

Features seen on Doppler radar:

(1) “bow” echo

(2) read inflow notch

(3) bookend vortices

 

Types of derecho:

(1) serial (associated with a very deep low, sublcassified into multi-bow and single-bow)

(2) progressive (moves along a stationary front)

(3) hybrid (mixed serial and progressive)